JPH076583B2 - Position control type air flow controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air flow control device for an internal combustion engine, and to a structure capable of reliably controlling the position of a valve body with respect to an input.

[Conventional technology]

The conventional air flow rate control device is configured to eliminate the influence of the suction negative pressure acting on the valve body, as described in Japanese Patent Publication No. 58-57623. However, because of the structure in which the plunger and the valve body that operate by energizing the electromagnetic body of the solenoid valve are integrated, the positional relationship between the air passage and the valve body that should be uniquely determined for the input (current) to the electromagnetic body is It is not uniquely determined because there is a pressure difference of air sandwiching the valve body, and the flow rate characteristic of air depends on the delicate balance between the valve body and the flow of air, which may cause disturbances such as variations in component accuracy. No consideration was given to obtaining weak and stable air flow characteristics.

[Problems to be solved by the invention]

In the above-mentioned prior art, because of the structure in which the plunger and the valve body are integrated, the positional relationship between the air passage and the valve body for the energization input to the electromagnetic body of the solenoid valve is not clear, and the valve placed in the flow of air is Since the flow rate characteristics depend on the balance between the body position and the air flow, no consideration is given to disturbance, and there is a problem that the flow rate characteristics become unstable.

An object of the present invention is to provide an air flow rate control device having stable flow rate characteristics.

[Means for solving problems]

The above object is achieved by providing a means for causing the valve body to faithfully follow the stroke amount of the plunger that operates by energizing the electromagnetic body of the solenoid valve. That is, the plunger and the valve body are separated, the valve body is driven by the diaphragm, the passage in the valve body for controlling the pressure of the diaphragm chamber to the atmospheric pressure, the valve seat of the plunger, and the orifice are provided,
This is achieved by constantly contacting the valve seat with the valve body and synchronizing the stroke of the valve body with the stroke of the plunger.

The configuration adopted by the present invention is as follows. There is one valve body that connects and disconnects an air passage consisting of an atmosphere chamber and an intake negative pressure chamber, and an air passage is formed in the center of the valve body, and one end of the passage is a valve provided in a plunger of an electromagnetic valve. Open and close with a seat.
Further, a diaphragm is provided on the outer circumference of the valve body at the other end of the passage to form a diaphragm chamber. The intake negative pressure chamber communicates with the diaphragm chamber through the orifice, and further communicates with the atmosphere chamber through the passage in the center of the valve body and the orifice.

[Action]

By moving the plunger of the solenoid valve in the direction to open the valve body and closing one end of the passage at the center of the valve body by the valve seat provided on the plunger of the solenoid valve, the diaphragm chamber and the atmosphere chamber are shut off. The differential pressure before and after the diaphragm disappears, and the valve body opens to the intake negative pressure chamber side due to the differential pressure between the atmosphere chamber before and after the valve body and the intake negative pressure chamber, and air flows. However, when the valve body opens, the valve seat provided on the plunger of the solenoid valve and one end of the passage in the center of the valve body separate and become open, and the pressure in the diaphragm chamber rises to the pressure in the atmosphere chamber, causing a negative suction pressure. Since the pressure in the pressure chamber is lower, the valve body operates in the closing direction due to the differential pressure across the diaphragm, and one end of the passage at the center of the valve body can be pushed by the valve seat provided on the plunger of the solenoid valve. That is, the stroke of the valve element can be synchronized with the stroke of the solenoid valve plunger in the opening direction.

On the other hand, when the plunger of the solenoid valve is moved in the direction to close the valve body and the valve seat provided on the plunger of the solenoid valve and one end of the passage in the center of the valve body are opened, the pressure in the diaphragm chamber is reduced to the pressure in the atmosphere chamber. Since the pressure rises and the pressure in the intake negative pressure chamber is lower, the valve body operates in the direction to close due to the differential pressure across the diaphragm, and the stroke of the valve body can follow the stroke in the closing direction of the solenoid valve plunger. .

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1 is a solenoid valve, and a valve seat 3 is provided at the tip of the plunger 2. Inside the body 4, a valve body 5, a diaphragm 6, and a spring 7 are arranged, and the diaphragm 6 has its center portion fixed to the valve body 5. A passage 9 is provided at the center of the valve body 5, one end of which faces the valve seat 3 of the plunger 2, and the other end of which has an orifice 11 which is electrically connected to the diaphragm chamber 10. The atmosphere chamber 12 communicates with the upstream side of a throttle valve of an internal combustion engine (not shown), and the suction negative pressure chamber 13
Is conducted downstream of the throttle valve. Atmosphere chamber 12 and suction negative pressure chamber
13 is opened and closed by the valve body 5. Also, the diaphragm 6
An orifice 14 that connects the diaphragm chamber 10 and the suction negative pressure chamber 13 is provided therein. The spring 7 acts in the direction of closing the valve body 5. Further, an orifice 15 is provided in the partition wall formed by the body 4 and the solenoid valve 1 and having the valve seat 3 and the atmosphere chamber 12, and one end of the valve body 5 and the valve seat 3 are provided. When separated, the atmosphere chamber 12 passes through the orifice 15, the passage 9 of the valve body 5, and the orifice 11 to the diaphragm chamber 10.
And conduct.

In such a structure, when a predetermined current is applied to the solenoid valve 1 during idle operation of the internal combustion engine, the plunger 2 and the valve seat 3 fixed to the plunger 2 move to the right by a value corresponding to the current. At this time, the stroke of the valve element can be made to follow the stroke of the plunger of the solenoid valve. The principle will be described. When the valve seat 3 and the tip of the passage 9 of the valve body 5 are separated from each other, the pressure in the suction negative pressure chamber 13 is equal to the orifice.
The pressure in the diaphragm chamber 10 acts on the diaphragm chamber 10 via the passage 9 of the valve body 5 and the orifice 15
The atmosphere chamber is introduced from, and the pressure in the suction negative pressure chamber 13 and the pressure in the diaphragm chamber 10 cause a pressure difference at a value determined by the diameters of the orifice 14 and the orifice 15. Since the atmospheric pressure is introduced into the diaphragm chamber 10, the pressure in the suction negative pressure chamber 13 is lower than that in the diaphragm chamber 10, and this pressure difference acts in the direction of closing the valve body 5. At this time, the atmosphere chamber 12 and the suction negative pressure chamber 13
Of course, a differential pressure occurs, and the pressure in the intake negative pressure chamber 13 is lower than that in the atmosphere chamber 12, so the differential pressure acts in the direction to open the valve body 5, but cannot overcome the force of the diaphragm 6 and the spring 7. Therefore, the valve body 5 is closed. However, when the solenoid valve 1 is energized and the valve seat 3 works to the right as shown in FIG. Since the pressure in the diaphragm chamber 10 becomes the same, the force to close the valve body 5 by the diaphragm 6 disappears, and the force to close the valve body 5 is only the spring 7. At this time, the pressure difference between the atmospheric chamber 12 and the suction negative pressure chamber 13 is
It becomes the suction negative pressure of the internal combustion engine itself, and its force overcomes the spring 7 sufficiently, so that the valve body 5 opens and the air becomes the first
It flows in the direction shown in the figure. When the air flows, the differential pressure before and after the valve body 5 decreases, and the spring 7 moves the valve body 5 toward the valve seat 3. As a result, the tip of the passage 9 of the valve body 5 and the valve seat 3 are kept constant. And the position of the valve body 5 is determined.

Therefore, according to the present invention, the position of the valve body 5 can be controlled by the urging force of the spring 7 and the connection and disconnection of the diaphragm chamber 10 and the atmosphere chamber 12 by the solenoid valve 1. However, these are irrelevant to the control of the position of the valve body 5.

〔The invention's effect〕

According to the present invention, since the position of the valve element can be controlled according to the input to the solenoid valve, stable flow rate characteristics can be obtained without being affected by disturbance, for example, dimensional accuracy or dispersion of component parts. effective.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of an embodiment of the present invention. 1 …… solenoid valve, 2 …… plunger, 3 …… valve seat, 4 …… body, 5 …… valve body, 6 …… diaphragm, 7 …… spring, 8…
… Cover, 9 …… Passage, 10 …… Diaphragm chamber, 11 …… Orifice, 12… Atmosphere chamber, 13… Suction negative pressure chamber, 14… Orifice, 15… Orifice.

Claims (1)

[Claims] 1. An electromagnetic valve, a solenoid valve, a valve seat fixed to a valve shaft of the electromagnetic valve and moving together with the valve shaft, a valve seat, and the intake air passage. A first air passage leading to the atmosphere side, a second air passage leading to the suction negative pressure side of the intake air passage, and a valve element for opening and closing the first air passage and the second air passage. In a position control type air flow rate control device comprising a body having a built-in body, a first space for containing the valve seat and the electromagnetic valve side tip of the valve body and a first air passage are electrically connected. One orifice is provided, a diaphragm is provided on the valve body on a side opposite to the solenoid valve, and a second space surrounded by the diaphragm and the body and the second air passage are electrically connected to each other. An orifice is provided, and a hollow third air passage is provided inside the valve body. And a tip of the third air passage on the side of the solenoid valve is opened to face the valve seat, a side of the third air passage on the diaphragm is opened to the second space, and the valve seat is The diaphragm is urged by the second urging means in the direction in which the valve body is closed, while being urged by the first urging means in a direction away from the opening of the third end of the third air passage on the electromagnetic valve side. Is energized, the valve seat overcomes the first urging means by energizing the solenoid valve, contacts the solenoid valve side tip of the third air passage, and closes the opening; The pressure difference between the pressure in the second space and the pressure in the second air passage disappears via the second orifice, and the pressure difference between the first air passage and the second air passage is reduced. The diaphragm is opened by the first air passage and the second air passage. The solenoid valve side tip of the third air passage of the valve body opened by the pressure difference between the air passage and the valve seat is separated, and the first air passage, the first orifice and the The first space, the third air passage, and the second space communicate with each other, and the pressure difference between the second space and the second air passage causes the valve body to close. A position control type air flow rate control device characterized by being driven.