JPS635151A - After fire preventing device for automobile - Google Patents

Abstract

PURPOSE:To prevent generation of an after fire, by contolling a coasting richer passage of a carburetor by an atmospheric pressure responsively acting member so that proper auxiliary fuel is supplied in the time of deceleration in no relation to the atmospheric pressure. CONSTITUTION:A carburetor provides a coasting richer passage 4 from a float chamber 3 to the downstream of a throttle valve 2. A control valve 11, which is provided in said passage 4, is opened and closed by a control unit 31. An atmospheric pressure responsively acting member 53 is provided in a control pressure system of the control valve. On the low ground, the member 53, which contracts a bellows 62 opening a hole 61 and introducing the atmospheric pressure into a chamber 57 through holes 64, 61, closes a hole 71 by a valve 76, and the carburetor, in which negative pressure of a hole 85 acts in a chamber 35 in the deceleration time pulling a diaphragm 33 to open the valve 11 through a rod 44, supplies auxiliary fuel. On the high ground, the bellows 62 closes the hole 61, and the carburetor, in which the negative pressure of the hole 85, acting in the chamber 57 in the deceleration time, is introduced into also a chamber 36 by opening the valve 76, opens the valve 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for preventing afterfire in a motor vehicle.

[Conventional technology]

In automobiles, it is called afterfire.
phenomenon may occur. Afterfire is
This is a phenomenon in which the fuel is not completely combusted in the combustion chamber of the engine, but combustion continues in the exhaust pipe.

Afterfire is likely to occur when the intake manifold negative pressure increases rapidly, such as when decelerating, dismounting, and shifting a car; this is because the air-fuel ratio required by the engine is very This is because it is lean.

Afterfire is not desirable because noise is generated when afterfire occurs.For convenience of explanation, in the following description, afterfire during deceleration of an automobile will be used as an example.

FIG. 2 is a longitudinal sectional view of a conventional afterfire prevention device for an automobile.

Examples of prior art documents disclosing the conventional afterfire prevention device as shown in Figure 2 include 1, for example, Toyota Motor Sales Co., Ltd. "Toyota Dyna New Model Manual", pages 88 and 89 (
(published August 25, 1978).

In FIG. 2, 1 is a carburetor, 2 is a throttle valve, and 3 is a float chamber. The carburetor 1 is provided with what is called a coasting glitcher passage 4. The coasting glitcher passage 4 opens into an intake passage 8 downstream of the throttle valve 2. A valve body 1 for opening and closing the coasting glitcher passage 4 is provided in the coasting glitcher passage 4.
1 is provided, and the valve body 11 is driven by a diaphragm 10 that moves in response to intake manifold negative pressure.

That is, when the intake manifold negative pressure becomes extremely high, such as when the automobile is decelerating, the compression coil spring 12 is defeated by the intake manifold negative pressure, and the diaphragm 10 moves in the direction of arrow A. Therefore, the coasting glitch intermediate passage 4 is opened and fuel is added from the coasting glitch passage 4. That's how it is.

The air-fuel ratio of the air-fuel mixture taken into the engine becomes rich as required by the engine, and afterfire is prevented from occurring.

During normal driving or idling, the intake manifold negative pressure is not as high as during deceleration, so the compression coil spring 1
2 overcomes the intake manifold negative pressure.

The diaphragm 10 remains moved in the direction of arrow B. Therefore, during normal speed or idling, the coasting glitcher passage 4 is closed, and it is the same as if the coasting glitcher passage 4 were not present.

[Problem that the invention attempts to solve]

The conventional afterfire prevention device shown in FIG. 2 does indeed prevent afterfire when the vehicle is traveling on level ground.

Afterfire still occurs when cars go to high altitudes. There was a problem. This is due to the following reason.

That is, in the case shown in Fig. 2, the diaphragm 10 is driven by the high intake manifold negative pressure during deceleration to open the coasting glitcher passage 4, but since the air becomes thinner at high altitudes, the intake manifold negative pressure is lower. It gets lower. Therefore, during deceleration at high altitudes, the negative pressure in the intake manifold cannot overcome the pressing force of the compression coil spring, and the diaphragm 10 moves as shown by arrow A.
This is because it does not move in any direction.

This problem appears to be solved by replacing the compression coil spring 12 with a weaker spring. However, if this is done, a problem arises in that the coasting glitch passageway 4 opens when the vehicle is being fitted on a flat surface. Therefore, simply changing the compression coil spring 12 to a weaker one will not solve the above problem.

The present invention solves these problems of the conventional technology.

The technical problem of the present invention is to prevent the occurrence of afterfire whether the vehicle is on level ground or on high ground.

[Means for solving problems]

゛ In order to achieve this technical problem, the following measures are taken in the present invention.

That is, 1. The 7-failure prevention device for an automobile according to the present invention includes a coasting glitcher passage for communicating the float chamber of the carburetor and the intake passage downstream of the throttle valve to supply additional fuel to the engine. , comprising a valve body for opening and closing the coasting glitcher passage, a first diaphragm and a second diaphragm, and driving the valve body by displacing the first diaphragm or the second diaphragm. and an altitude compensator that applies an intake manifold negative pressure to the first diaphragm on flat ground and applies intake manifold negative pressure to the second diaphragm on high ground. The diaphragm device includes a first compression coil spring that presses the first diaphragm against intake manifold negative pressure, and a second compression coil that presses the second diaphragm against intake manifold negative pressure. A spring is provided. The first diaphragm is displaced only when negative pressure from the intake manifold that overcomes the pressing force of the first compression coil spring acts on the first diaphragm, causing the valve body to displace the coasting. The richer passage is opened, and the second diaphragm is displaced only when a negative pressure in the intake manifold that overcomes the pressing force of the second compression coil spring acts, causing the valve body to move through the course. Open the Teigritcha passage.

[Effect]

Consider the case when the car is on flat ground and decelerating.

In the device of the present invention, the intake manifold negative pressure acts on the first diaphragm. Since it is during deceleration, the intake manifold negative pressure is very high, and overcomes the pressing force of the first compression coil spring, displacing the first diaphragm and opening the coasting richer passage. Therefore, since fuel is added from the coasting glitcher passage, the engine's required value for the air-fuel ratio is met, and afterfire does not occur.

Consider the case when a car is at a high altitude and decelerates.

This time, intake manifold negative pressure acts on the second diaphragm. This intake manifold negative pressure overcomes the pressing force of the second compression coil spring. Accordingly, the second diaphragm is displaced to cause the valve body to open the coasting glitcher passage. For this reason.

Similarly, no afterfire occurs because fuel is added to the engine through the coasting richer passage.

If the car is on level ground and the vehicle is off the plate during deceleration 9 For example, if we consider the case during normal driving or idling, even in such a case, the intake manifold negative pressure acts on the first diaphragm, but 8 the intake manifold negative pressure The pressure is not as high as during deceleration, so the intake manifold negative pressure cannot overcome the pressing force of the first compression coil spring, so the first diaphragm is not displaced, so the valve body is coasting. Since the char passage is not opened, fuel is not added through the coasting glitcher passage.

The same is true if the car is at a high altitude and is off the board when decelerating.

That is, 2. For example, if a car is located at a high altitude, it is normal.

Consider the case when the vehicle is running or idling.

In such a case, the intake manifold negative pressure still acts on the second diaphragm, but the intake manifold negative pressure is not as high as during deceleration. Therefore, the intake manifold's negative pressure cannot overcome the pressing force of the second compression coil spring, so
Since the second diaphragm is not displaced and therefore the five valve body does not open the coasting glitcher passage, no fuel is added through the coasting glitcher passage.

As can be seen from the above description, according to the present invention.

Whether the car is on level ground or at high altitude.

Generation of afterfire is prevented. However, when the vehicle is in normal operation or idling, the coasting glitch passage & is closed and is not opened.

〔Example〕

FIG. 1 is a longitudinal sectional view of an afterfire prevention device for an automobile according to an embodiment of the present invention.

In FIG. 1, 1 is a carburetor, 2 is a throttle valve, and 3 is a float chamber. 8' represents the intake passage in one carburetor. The carburetor 1 is attached to an intake manifold 22.

A coasting glitcher passage 4 is provided in the carburetor 1. One end of the coasting lithochamber passage 4 is connected to the float chamber 3.

The other end 23 is opened to the intake air i8 downstream of the throttle valve 2. 24.25 is coasting glincher passage 4
It is a dedicated air bleed.

The coasting glitcher passage 4 is provided with a valve body 11 that opens and closes the coasting glitcher passage 4. The valve body 11 is driven by a diaphragm device 31 .

In the diaphragm device 31, the inside of a diaphragm case 32 is partitioned into three chambers 35, 36, and 37 by a first diaphragm 33 and a second diaphragm 34.

For convenience of explanation, the chamber 35 will be referred to as the first chamber, the chamber 36 as the second chamber,
Chamber 37 will be referred to as the third chamber. A first compression coil spring 41 is arranged in the first chamber 35 . The first compression coil spring 41 presses the first diaphragm 33.

A second compression coil spring 42 is arranged in the second chamber 36 . The second compression coil spring 42 is arranged between the first diaphragm 33 and the second diaphragm 34 so as to press the first diaphragm 33 and the second diaphragm 34.

The first compression coil spring 41 is the second compression coil spring 42
Something stronger than that is used.

No compression coil spring is arranged in the third chamber 37.
The third chamber 37 is always open to the atmosphere through an atmosphere communication hole 43 formed in the diaphragm case 32.

A rod 44 is connected to the second diaphragm 34, and the above-mentioned valve body 11 is attached to the tip of the rod 44. Further, the rod 44 protrudes into the second chamber 36, and an enlarged portion 45 is attached to the tip of the loft 44. A cylindrical member 46 protruding into the second chamber 36 is attached to the first diaphragm 33, and a through hole 52 is bored in the end surface 51 of the fifth cylindrical member 46. The rod 44 is loosely fitted into the through hole 52.

The enlarged portion 45 is present within the cylindrical member 46 .

53 is an altitude compensator. A diaphragm device 54 is attached to the altitude compensator 53 .

In the diaphragm device 54, the inside of a diaphragm case 59 is partitioned by a diaphragm 55 into an upper diaphragm chamber 56 and a lower diaphragm chamber 57. A compression coil spring 79 that presses the tire phragm 55 is arranged in the lower diaphragm chamber 57 . A very weak compression coil spring 79 is used.

The lower diaphragm chamber 57 can communicate with the atmosphere via an orifice 61. A bellows 62 is arranged inside the altitude compensator 53.

A valve body 63 for opening and closing the orifice 61 is attached to the tip of the bellows 62. The bellows 62 is contracted when the vehicle is on level ground.

Therefore, the valve body 63 opens the orifice 61. When the vehicle is at a high altitude, the bellows 62 is expanded, and the valve body 63 therefore closes the orifice 61.

Therefore, when the vehicle is on level ground, the lower diaphragm chamber 57 is in communication with the atmosphere, and when the vehicle is on high ground, the lower diaphragm chamber 57 is isolated from the atmosphere.

64 is a filter element.

The diaphragm case 59 has a first valve boat 71 and a second valve boat 71.
A valve boat 72 is provided. 1st valve bo) 7
1 is connected to the first chamber 35 of the diaphragm device 31 via a first passage 73. The second valve port 72 is connected to the upper diaphragm chamber 56, which communicates with the atmosphere via a filter element 74.

A rod 75 is connected to the diaphragm 55, and a first valve body 76 and a second valve body 77 are attached to the rod 75. The first valve body 76 is connected to the first valve port 71
The second valve element 77 opens and closes the second valve boat 72. As mentioned earlier, the first
The second valve body 76 and the second valve body 77 are fixed to the rod 75. h, when the diaphragm 55 moves downward and the first valve body 76 opens the first valve boat 71, the second valve body 77 closes the second valve boat 72;
When the diaphragm 55 is displaced upward and the first valve body 76 closes the first valve boat 71, the second valve body 77
opens the second valve boat 72.

The diaphragm case 59 is further provided with a third port 81. The third port 81 is connected to the first valve port 71 and the second valve boat 72 in the diaphragm case 59.
exists between. The third boat 81 is located in the second passage 82
It is connected to the second chamber 36 of the diaphragm device 31 via.

A third passage 83 is connected to the lower diaphragm chamber 57, and the other end of the third passage 83 is connected to the middle of the first passage 73. Further, a fourth passage 84 branches off from the middle of the first passage 73, and the fourth passage 84 is connected to a negative pressure boat 85 bored in the intake manifold 22.

The operation of this embodiment will be explained.

Consider the case when the car is on flat ground and decelerating.

Since the automobile is on level ground, the orifice 61 of the altitude compensator 53 is open. 7 Therefore.

Since the lower diaphragm chamber 57 is at atmospheric pressure, the first valve body 76 closes the first valve port 71 due to the pressing force of the compression coil spring 79.

The second valve body 77 opens the second valve port 72.

Therefore, atmospheric air is introduced into the second chamber 36 of the diaphragm device 31 from the filter element 74 through the upper diaphragm chamber 56, the second valve port 72, the third port 81, and the second passage 82. , the second chamber 36 is at atmospheric pressure.

On the other hand, the intake manifold negative pressure is introduced into the first chamber 35 of the diaphragm device 31 from the negative pressure boat 85 via the fourth passage 84 (this intake manifold negative pressure is introduced from the first passage 73 Although the pressure is leaking to the atmosphere through the lower diaphragm chamber 57 and the orifice 61, negative pressure is still generated in the first chamber 35).

(Thus, the compression coil spring 41 is defeated by the negative pressure in the first chamber 35 and the first diaphragm 33 is pulled in the direction of arrow A. However, when the first diaphragm 33 is displaced in the direction of arrow A, the 9 cylindrical member 46 This is because the ampulla 45 is pulled in the direction indicated by the arrow.

Eventually, the valve body 11 opens the coasting glitcher passage 4.

Therefore, when the vehicle is on flat ground and decelerating, fuel is added through the coasting glitch passage 4, so that the air-fuel ratio required by the engine is met and no afterfire occurs.

Consider the case when a car is at a high altitude and decelerates.

Since the vehicle is at a high altitude, the orifice 61 of the altitude compensator 53 is blocked. Therefore.

Since the intake manifold negative pressure is guided to the lower diaphragm chamber 57 via the third passage 83, the first passage 73, the fourth passage 84, and the negative pressure boat 85, the lower diaphragm chamber 57 is under negative pressure. It has become.

Therefore, since the compression coil spring 79 is defeated by the negative pressure and the diaphragm 55 is displaced downward, the first valve element 76 opens the first valve boat 71.

The second valve body 77 closes the second valve boat 72 .

The second chamber 36 of the two-diaphragm device 31 therefore has a passageway 84 to a first passageway 73 and a first valve port 71 .
Negative pressure is introduced through the third boat 81 and the second passage 82, and the second chamber 36 becomes a negative pressure (note that the first chamber 35 of the diaphragm device 31 also has a negative pressure). pressure boat 8
5 through the fourth passage 84).

Thus, the compression coil spring 42 is defeated by the negative pressure in the second chamber 36 and the second diaphragm 34 is pulled in the direction of arrow A. However, when the second diaphragm 34 is displaced in the direction of arrow A, Since the valve body 11 moves in the direction indicated by the arrow, the valve body 11 eventually opens the coasting glitcher passage 4.

Therefore, even when the vehicle is at a high altitude and decelerating, fuel is added through the coasting glitcher passage 4, so no afterfire occurs.

When the automobile is on flat ground and is not decelerating (2), for example, when the vehicle is in normal driving or idling, in such a case, the second chamber 36 of the diaphragm device 31 is Although the pressure is atmospheric and the intake manifold negative pressure is introduced into the first chamber 35, the intake manifold negative pressure is not as high as the intake manifold negative pressure during deceleration.
There is not enough force to overcome the compression coil spring 41. Therefore, the first diaphragm 33 is not pulled in the direction of the arrow.
Therefore, since the valve body 11 closes the coasting glincher passage 4, fuel is not added through the coasting glitch passage 4.

When the vehicle is at a high altitude and is not decelerating (1) For example, when the vehicle is in normal driving or idling, in such a case, the first chamber 35 of the diaphragm device 31 is Similarly, although the pressure is negative and the second chamber 36 is also negative pressure.

Since the intake manifold negative pressure is not as high as the intake manifold negative pressure during deceleration, the negative pressure in the second chamber 36 is reduced by the compression coil spring 42.
I don't have the power to defeat you. Therefore, the second diaphragm 3
4 is not pulled in the direction of the arrow, therefore, the valve body 11
is blocking the coasting glitcher passage 4,
No fuel is added through the coasting glitcher passage 4.

As can be seen from the above description, according to one embodiment.

Whether the car is on level ground or at high altitude.

Generation of afterfire is prevented. However, when the vehicle is in normal operation or idling, the coasting glitch passage is closed and is not opened.

Although two specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, but includes various embodiments within the scope of the claims.

〔Effect of the invention〕

According to the present invention, afterfire is prevented from occurring whether the vehicle is on level ground or on high ground. This effect is achieved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a seven-day lid tire prevention device for an automobile according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of a conventional afterfire prevention device for an automobile. 1--Carburizer 2--Throttle valve 3--Float chamber 4--Coast glitcher passage 8--
--- One intake passage 11 --- Valve body 31 --- One diaphragm device 33 --- First diaphragm 34 --- Second diaphragm 41. ---First compression coil spring 42, ---, Second compression coil spring 53, ---
・Altitude compensation device

Claims (1)

[Claims] a coasting richer passage for communicating the float chamber of the carburetor and the intake passage downstream of the throttle valve to supply additional fuel to the engine; a valve body for opening and closing the coasting richer passage; and a second diaphragm, the diaphragm device driving the valve body by displacing the first diaphragm or the second diaphragm, and applying an intake manifold negative pressure to the first diaphragm on a flat ground. and an altitude compensation device that applies intake manifold negative pressure to the second diaphragm at high altitudes, and the diaphragm device includes a first diaphragm that presses the first diaphragm against the intake manifold negative pressure. and a second compression coil spring that presses the second diaphragm against intake manifold negative pressure, the first diaphragm being compressed by the first compression coil spring. The second diaphragm is displaced only when negative intake manifold pressure that overcomes the pressing force acts on the first diaphragm, causing the valve body to open the coasting richer passage. An automobile aftermarket characterized in that the valve body is displaced only when a negative pressure of the intake manifold that overcomes the pressing force of the second compression coil spring is applied to open the coasting richer passage. Fire prevention device.