JPS6027792Y2 - Throttle valve opening control device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a throttle valve opening control device, and is particularly suitable for use in an automobile internal combustion engine with exhaust gas purification measures. The present invention relates to an improvement in a throttle valve opening control device having an energized throttle valve and a bushing rod for preventing movement of the throttle valve in the closing direction under certain operating conditions.

In general, harmful emissions generated from internal combustion engines such as automobile engines include hydrocarbons HC, carbon monoxide CO, and nitrogen oxides NOX.

Of these, hydrocarbon RC is generated due to incomplete combustion, the flame-extinguishing effect of the combustion chamber wall surface, and misfire phenomena.In particular, when the throttle valve is suddenly fully closed during engine braking, the negative pressure in the intake pipe increases. Due to the sudden rise in temperature, the adhering fuel in the intake manifold evaporates rapidly, and a large amount of fuel is sucked into the engine combustion chamber. Furthermore, since the absolute amount of intake air is insufficient, ignition performance is poor, resulting in a misfire or semi-misfire condition. Therefore, a large amount of unburned fuel is discharged as hydrocarbon HC.

This shall prevent the emission of hydrocarbons during engine braking, prevent over-enrichment of the air-fuel mixture during deceleration,
In addition, by securing a certain amount of intake air mixture,
M-speed control devices such as dashpots and throttle positioners have been proposed to improve combustion, prevent misfires, and suppress the generation of hydrocarbon HC.

Among these, the former dashpot includes a throttle valve 16 disposed downstream of the venturi 14 in the intake passage 12 and biased in the fully closing direction by a predetermined closing force, as shown in FIG. 1, for example. The carburetor 10 includes a bushing rod 20 for preventing movement of the throttle valve 16 in the closing direction, and a diaphragm 2 to which the rear end of the bushing rod 20 is completely fixed.
2. a diaphragm device 18 having a spring 24 with a force smaller than the closing force of the throttle valve 16, which urges the diaphragm 22 in a direction to advance the bushing rod 20;
A check valve 26a and a throttle 26 connected in parallel to each other are connected to the diaphragm chamber 23 of the diaphragm device 18.
The negative pressure delay valve 26 is provided with a negative pressure delay valve 26 having an opening having a diameter of 1.b, and an air filter 28 for introducing clean air into the negative pressure delay valve 26.

In the figure, 30 is an air cleaner for introducing clean air into the intake passage 12, 32 is an intake manifold for distributing and supplying the air-fuel mixture formed in the carburetor 10 to the engine combustion chamber, and 34 is an air cleaner for introducing clean air into the intake passage 12. This is an adjustment screw for adjusting the contact position between the bushing rod 20 and the throttle valve lever 17 of the throttle valve 16.

In this dashpot, when the engine is stopped, the return spring force of the throttle valve 16 that applies a closing force to the throttle valve 16 is stronger than the compression spring 24 of the diaphragm device 18, so the throttle valve lever 17 resists the compression spring 24. The bushing rod 20 is pushed back to the right in the figure, and the throttle valve 16 is set to a fully closed state or a predetermined idling opening.

When the engine is in operation, the throttle valve 16 is opened in conjunction with an accelerator (not shown), so the throttle valve lever 1
7 and the adjustment screw 34 are disengaged, while the adjustment screw 34 and the bushing rod 20 are quickly introduced into the diaphragm chamber 23 via the compression spring 24, the air filter 28, and the negative pressure delay valve 26. Due to the action of the atmosphere, it protrudes to a predetermined forward position.

When the accelerator is suddenly closed for some reason, such as when the vehicle is decelerating, and a closing force is applied to the throttle valve 16, the throttle valve 16 is rotated in the direction of the closing force by the return spring force.

The opening degree of the throttle valve becomes small, and the throttle valve lever 17 is moved by the adjustment screw 3.
4, the closing force of the throttle valve 16 causes the compression spring 24 and the atmospheric pressure accumulated in the diaphragm chamber 23 to cause the throttle valve 16 to close via the bushing rod 20 and the adjustment screw 34. Since a blocking force is applied to the throttle valve lever 17, the throttle valve 16 is prevented from closing rapidly, and the return spring force of the throttle valve 16, which overcomes the compression spring 24 and the atmospheric pressure in the diaphragm chamber 23,
gradually closed.

At this time, the operating characteristics of the diaphragm 22 of the diaphragm device 18, that is, the opening control state of the throttle valve 16, are determined by the following: Backflow from the diaphragm chamber 23 of the diaphragm device 18 toward the air filter 28 via the throttle 26b of the negative pressure delay valve 26 determined by the atmospheric conditions.

In this way, even if the throttle valve 16 attempts to close suddenly, the diaphragm device 18 prevents this sudden closing, thereby preventing the negative pressure in the intake manifold 32 from increasing rapidly, and Since a certain amount of intake air-fuel mixture is secured, combustion is improved, misfires are prevented, and generation of hydrocarbon HC is suppressed.

However, in this dashpot, since the force of the compression spring 24 is smaller than the closing force of the throttle valve 16, it has the advantage of increasing the set opening of the throttle valve at which the dashpot begins to operate. The throttle valve opening returned to the idling opening, making it difficult to maintain the throttle valve opening larger than the idling opening when starting the engine.

On the other hand, the latter throttle positioner is connected to the diaphragm chamber 2 in a deceleration control device similar to the dashpot.
The force of the compression spring 24, which introduces negative intake pressure instead of the atmosphere into the throttle valve 1 and energizes the diaphragm 22, is applied to the throttle valve 1.
6. Therefore, when the engine is stopped, the throttle valve opening can be maintained larger than the idling opening, which is advantageous when starting, but when the intake negative pressure becomes low. Considering that the spring force of the throttle positioner is stronger, there is a problem in that the opening degree cannot be set too large in order to prevent the throttle positioner from being over-tightened.

The present invention was developed to eliminate the above-mentioned drawbacks of the conventional technology, and it is possible to increase the set opening at which the bushing rod, which prevents the throttle valve from moving in the closing direction, begins to act on the throttle valve. An object of the present invention is to provide a throttle valve opening control device that can maintain a throttle valve opening larger than an idling opening.

The present invention provides a throttle valve opening control that includes a throttle valve that is biased in the fully closing direction by a predetermined closing force and a bushing rod that prevents the throttle valve from moving in the closing direction under specific operating conditions. In the device, a first diaphragm to which a rear end of the bushing rod is fixed, and a first force smaller than a closing force of the throttle valve that biases the first diaphragm in a direction to advance the bushing rod. a second diaphragm to which a rear end of a stopper is fixed, the front end of which can come into contact with the first diaphragm; the second diaphragm is biased in a direction to advance the stopper; a second spring with a force greater than the closing force of the throttle valve;
A heavy diaphragm device is provided, and atmospheric air is introduced into a first diaphragm chamber behind a first diaphragm of the double diaphragm device through a negative pressure delay valve, and atmospheric air is introduced into a second diaphragm chamber behind a second diaphragm of the double diaphragm device. This is a distant relative of the above purpose by introducing negative intake pressure into the diaphragm chamber through a check valve when the engine is running, and introducing atmospheric air when the engine is stopped.

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 2, this embodiment includes a throttle valve 16 that is biased in the fully closing direction by a predetermined closing force, similar to the conventional one;
A throttle valve opening degree control device includes a bushing rod 20 for preventing the movement of the throttle valve 16 in the closing direction under specific operating conditions. a first compression spring 24 with a force smaller than the closing force of the throttle valve 16, which urges the first diaphragm 22 in the direction of advancing the bushing rod 20; A second diaphragm 42 to which the rear end of the first stopper 40 is fixed; and the throttle valve 16 that biases the second diaphragm 42 in a direction to advance the stopper 40.
a double diaphragm device 38 having a second compression spring 44 with a force greater than the closing force of the second diaphragm device 38 and a second stopper 45 regulating the retraction limit of the second diaphragm 42; A negative pressure delay valve 26 and an air filter 28 connected to the first diaphragm chamber 23 at the rear of the first diaphragm 22, similar to the conventional ones, and
A check valve 46 connected to a second diaphragm chamber 43 behind the second diaphragm 42 of the heavy diaphragm device 38 for transmitting the intake pipe negative pressure in the intake manifold 32 to the second diaphragm chamber 43. and a diaphragm 48 and also the second diaphragm chamber 4 of said double diaphragm device 38.
3, an electromagnetic on-off valve 50 and an air filter 52
It is equipped with the following.

The electromagnetic on-off valve 50 is connected to a valve body 50a, a compression spring 50b that always urges the valve body 50a to the left in the figure, and an ignition switch 52, and is connected to a power supply when the ignition switch 52 is closed. It has a solenoid t'50c which is connected to the valve body 50a and sucks the valve body 50a to the right in the figure.

The action will be explained below.

First, when the engine is stopped before starting the engine, the ignition switch 52 is open, so the valve body 50 of the electromagnetic on-off valve 50
a is at the left position as shown in FIG. 2 due to the action of the compression spring 50b, and therefore, atmospheric air is introduced into the second diaphragm chamber 43 through the air filter 52.

Therefore, due to the action of the second compression spring 44 whose force is set to be stronger than the closing force of the throttle valve 16, the second diaphragm 42 is displaced to the left in the figure. The first stopper 40 fixed to the diaphragm 22 also displaces the first tire flamm 22 to the left in the figure, so that the bushing rod 20 fixed to the first diaphragm 22 is also displaced to the left in the figure.
The throttle valve 16 is also pushed to the left in the drawing, and the throttle valve 16 is held at a predetermined opening degree defined by the adjustment screw 34, which is larger than the idling opening degree, via the adjustment screw 34 and the throttle valve lever 17.

Therefore, starting the engine becomes easy.

On the other hand, when the engine is operating, that is, when the ignition switch 52 is closed, the solenoid 50c of the electromagnetic on-off valve 50 is energized, and the valve body 50a is attracted to the solenoid 50c, causing the electromagnetic on-off valve 50 to The flow path inside is blocked.

Therefore, no air is introduced into the second diaphragm chamber 43 of the double diaphragm device 38, and the check valve 46
The intake pipe negative pressure within the intake manifold 32 is guided through the throttle 48 and the intake pipe negative pressure is maintained by the action of the check valve 46.

Therefore, regardless of changes in the intake pipe negative pressure due to changes in engine operating conditions, the pressure inside the second diaphragm chamber 43 is maintained at a predetermined high negative pressure, and the second diaphragm 42 is connected to the second compression spring 44. against this, it is sucked and held to the right position where it comes into contact with the second stopper 45.

The position of the second stopper 45 is selected so that the first stopper 40 does not come into contact with the first diaphragm 22 even if the throttle valve 16 returns to the idling opening due to the closing force. In this case, the first diaphragm 22 is displaced depending on the state of the pressure introduced into the first diaphragm chamber 23 by the air filter 28 via the negative pressure delay valve 26, and thereby the conventional The same action as a dashpot is performed.

That is, in the case of deceleration from steady state or acceleration, the throttle valve 16 changes from an open state, that is, a state where the first diaphragm 22 is pushed to the left in the figure by the first compression spring 24. When the throttle valve lever 17 first hits the adjusting screw 34, the pressure in the first diaphragm chamber 23 between the first diaphragm 22 and the second diaphragm 42 is increased through the throttle 26b of the negative pressure delay valve 26. As a result, the first diaphragm 22 gradually moves to the right in the figure, and the throttle valve opening gradually returns to the idling opening.

Next, when the engine is restarted after stopping, the air is introduced into the second diaphragm chamber 43 via the electromagnetic on-off valve 50 as described above, so the throttle valve 16 is opened to a predetermined opening degree. When the ignition switch 52 is closed and the engine is started, negative pressure in the intake pipe is generated.The negative pressure in the intake pipe is gradually introduced into the second tire diaphragm 42 through the throttle 48, and the second diaphragm 42 is gradually pressed down. Then, it moves to the right position where it abuts the second stopper 45.

Therefore, the throttle valve 16 also gradually returns to its idling opening.

In the case of a simple double structure, when the second diaphragm 42 functioning as a throttle positioner operates, the volume of the first diaphragm chamber 23 formed between the second diaphragm 42 and the first diaphragm 22 increases. change,
First tire flam 22 functioning as a dashpot
However, in the present invention, the negative pressure introduced into the second diaphragm chamber 43 is maintained by the check valve 46, thereby reducing the function of the dashpot. The position of the second diaphragm 42 is always maintained at a predetermined position, and the above-mentioned problem does not occur.

Furthermore, if the negative pressure in the second diaphragm chamber 43 is maintained in this manner, the throttle valve opening may return to the idling opening when the engine is stopped; however, in the present invention, Since the atmosphere is introduced into the second diaphragm chamber 43 when the engine is stopped through the electromagnetic on-off valve 50 operated by the ignition switch 52, such a problem does not occur.

As explained above, according to the present invention, the opening of the throttle valve can be kept larger than the idling opening during deceleration and gradually decreased, so that unburned gas, which is often discharged during deceleration, can be reduced.

Furthermore, when starting the engine, the throttle valve opening can be set larger than the idling opening, which has the excellent effect of improving startability.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of a carburetor equipped with a conventional dashpot, and FIG. 2 is a configuration of a carburetor equipped with an embodiment of the throttle valve opening control device according to the present invention. FIG. 16... Throttle valve, 17... Throttle valve lever, 20... Bush rod, 22.42...
...Diaphragm, 23,43...Diaphragm chamber, 24,44...Compression spring, 26...
... Negative pressure delay valve, 28.52 ... Air filter, 38 ... Double diaphragm device, 40.
...Stopper, 46...Check valve, 5o.
...Solenoid on-off valve 52...Ignition switch.

Claims (1)

[Scope of utility model registration request] The throttle valve opening control device includes a throttle valve that is biased in the fully closing direction by a predetermined closing force, and a bushing rod that prevents movement of the throttle valve in the closing direction under specific operating conditions. The first one to which the rear end of the bushing rod is fixed.
a diaphragm, a first spring having a force smaller than the closing force of the throttle valve, which biases the first diaphragm in a direction to advance the bushing rod, and a front end of which is in contact with the first diaphragm. a second diaphragm to which the rear end of a possible stop is fixed; and a second spring having a force greater than the closing force of the throttle valve, which biases the second diaphragm in the direction of advancing the stopper. A double diaphragm device is provided, in which atmospheric air is introduced into a first diaphragm chamber behind a first diaphragm of the double diaphragm device through a negative pressure delay valve, and atmospheric air is introduced into a first diaphragm chamber behind a second diaphragm of the double diaphragm device. A throttle valve opening control device characterized in that intake negative pressure is introduced into the second diaphragm chamber through a check valve when the engine is running, and atmospheric air is introduced into the second diaphragm chamber when the engine is stopped.