JPH0349341Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a flow rate control device used in an automobile exhaust gas purification system, etc. A flow control device with a reed valve is provided with a reed valve in the reed valve, and one on-off valve is arranged on the upstream side of the reed valve. In particular, when the on-off valve is opened, the flow rate of the fluid flowing from the inflow path to the outflow path is set in three stages. It relates to something that can be variably controlled.

(Prior Art) Conventionally, a flow control device with a reed valve as shown in FIG. 3 is known. That is, the inlet passage 102 and the outlet passage 1 formed in the valve housing 101
A reed valve 105 is provided between the reed valve 105 and the reed valve 105, and an on-off valve 106 is provided upstream of the reed valve 105.
The on-off valve 106 includes a valve seat member 107 whose outer circumferential portion is fixed to the valve housing 101 and which has a valve hole 107a in the central portion, and a valve seat member 107 which is disposed above the valve seat member 107 so as to be movable in the vertical direction. It consists of a valve body 108 that can open and close the hole 107a. One end of a valve rod 109 that is vertically slidably supported by the valve housing 101 is fixed to the valve body 108.
The other end is fixed to the center of a diaphragm 110 whose outer periphery is held between the valve housing 101, and the diaphragm 110 connects the inside of the valve housing 101 to an atmospheric pressure chamber 111 communicating with the atmosphere and a negative pressure source (Fig. (not shown)
It is divided into a negative pressure chamber 112 and a negative pressure chamber 112 which is communicated with.
A coil spring 113 that urges the diaphragm 110 downward is installed in the negative pressure chamber 112, and the diaphragm 110 is pressed toward the atmospheric pressure chamber 111 by the spring 113. The valve body 108 is pressed so as to be seated on the valve seat member 107, thereby closing the valve hole 107a.

Further, the inlet passage 102 is communicated with the atmosphere, and the outlet passage 103 is communicated with the negative pressure side, and when the negative pressure in the outlet passage 103 exceeds a certain value, the reed valve 105 is opened by the negative pressure. As shown in FIG. 4, when the negative pressure in the negative pressure chamber 112 exceeds a predetermined value A, the diaphragm 110 is caused to spring 1 by the negative pressure.
The valve body 108 is moved toward the negative pressure chamber 112 against the biasing force of the valve member 13, and the valve body 108 is separated from the valve seat member 107 and closed to the valve hole 1.
07a and when the negative pressure exceeds a predetermined value B, the valve body 108 completely opens the valve hole 107a, and even if the negative pressure increases thereafter, the flow rate of the fluid passing through the valve hole 107a remains constant. become.

In addition, in FIG. 3, 114 is a valve seat of the reed valve 105 equipped with a valve hole 114a, 115 is a reed valve body, 1
16 is a lead stopper.

(Problem to be Solved by the Invention) However, in the conventional example described above, when the on-off valve 106 is opened and closed, the entire amount of fluid from the inflow passage 102 is transferred to the valve hole 107a of the on-off valve 106 and the valve hole 114a of the reed valve 105. through the outflow passage 103, while when the on-off valve 106 is closed, the inflow passage 10
2 to the outflow path 103 is completely blocked. Therefore, by changing the negative pressure in the negative pressure chamber 112, the fluid flow rate can only be changed in two stages (zero or very small amount and maximum amount). Therefore, if it is necessary to variably control the flow rate of the fluid in three or more stages, a special actuator that controls the opening amount of the on-off valve 106 in three or more stages may be used, or an on-off valve such as a solenoid valve may be used. Therefore, there were problems in that the structure became complicated and the number of parts increased, leading to an increase in costs.

Therefore, the present invention was developed with a focus on the above-mentioned problems, and its purpose is to reduce negative pressure by using only one on-off valve, without requiring two or more special actuators or on-off valves. It is an object of the present invention to provide a flow control device with a reed valve that is simple in structure and inexpensive and can variably control the flow rate of fluid in three stages according to changes.

(Means for Solving the Problems) In order to achieve the above object, the present invention divides the inflow path formed in the valve casing into a first and second inflow path by a partition wall, and also includes an on-off valve in the partition wall. A through hole is bored at a position facing the valve hole formed in the valve seat member,
The valve body of the on-off valve is disposed between the through hole and the valve hole so that the valve hole and the through hole can be selectively opened and closed by the valve body.

(Function) Negative pressure acts in a pulsating manner in the outflow passage, and the reed valve repeatedly opens and closes, but until the negative pressure in the negative pressure chamber reaches a predetermined value, the valve hole is closed and the intake air is Not achieved (first stage).

Next, when the negative pressure in the negative pressure chamber reaches a predetermined value, the negative pressure causes the valve body to separate from the valve seat member, and the valve hole communicates with the inflow path. At this time, since a negative pressure is applied to the inside of the outflow path, air is drawn into the outflow path from the inflow path. In this state, both the first and second inflow passages communicate with the valve hole of the valve seat member (second stage).

Then, the negative pressure in the negative pressure chamber further increases and the second
When the predetermined value in the step is exceeded, the negative pressure causes the valve body to seat against the partition wall and close the passage hole. In this state, communication between the first inflow path and the outflow path is cut off, and only the second inflow path communicates with the outflow path via the valve hole.
Therefore, at this time, the flow rate from the inflow path to the outflow path becomes a value that is smaller than the value in the second stage (third stage).

In this way, the flow rate is variably controlled in three stages, from the first stage to the third stage, according to changes in negative pressure by one on-off valve.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment in which a flow rate control device with a reed valve according to the present invention is applied to a secondary air introduction system for exhaust gas control of a vehicle engine. In FIG. 1, 1 is a valve housing, and this valve housing 1 consists of a valve housing body 1a and a lid body 1b attached to the upper end of the valve housing body 1a.
Inside, there is an inflow passage 2 that communicates with the atmosphere side, that is, a portion of the engine intake passage (not shown) upstream of the throttle valve (not shown), and a negative pressure side, that is, the engine intake passage (not shown). ) is formed with an outflow path 3 that communicates with a portion on the downstream side of the throttle valve (not shown). The inflow path 2 is connected to the first inflow path 2 by the partition wall 4.
The partition wall 4 is formed with through holes 4a, 4a, . , the first inflow path 2a and the second inflow path 2b are communicated with each other through the through holes 4a, 4a, . . . .

A valve chamber 10 is provided between the second inflow path 2b and the outflow path 3 within the valve housing body 1a, and the valve chamber 1
0 is provided with a reed valve 11 and an on-off valve 5. The reed valve 11 is airtightly attached to the valve housing main body 1a via a gasket 13 on the outer periphery, and includes a valve seat 14 having a valve hole 14a in the center, and a side surface of the valve seat 14 on the outflow path 3 side. The reed valve body 16 is usually seated on the valve seat 14 and closes the valve hole 14a, but if the negative pressure in the outflow passage 3 exceeds a certain value. and opens the valve hole 14a.

The on-off valve 5 provided on the upstream side of the reed valve 11 includes a valve seat member 6 whose outer periphery is sandwiched between a gasket 13 and a valve housing body 1a, and which has a valve hole 14a in the center, and the valve seat member 6. It consists of a valve body 18 disposed above, and a valve rod 20 whose one end is fixed to the valve body 18 and the other end is fixed to the diaphragm 19, and the valve rod 20 has first and second inflow passages 2a, 2b
An annular guide portion 4b integrally formed with the partition wall 4 between
is fitted to be slidable vertically.

The outer periphery of the diaphragm 19 fixed to the valve rod 20 is held between the upper end surface of the valve housing body 1a and the lower end surface of the lid body 1b, and a negative pressure chamber 25 is defined inside the lid body 1b by the diaphragm 19. The negative pressure chamber 25 is in communication with a negative pressure source, for example, a portion of the intake passage (not shown) of the engine downstream of a throttle valve (not shown), and the negative pressure chamber 25 of the diaphragm 19 is connected to On the side opposite to the chamber 25, an atmospheric pressure chamber 26 is defined by the valve housing body 1a, the diaphragm 19, and the partition wall 4, and the atmospheric pressure chamber 26 is connected to the first inflow path 2a.
is communicated with.

A coil spring 27 is compressed in the negative pressure chamber 25, and this coil spring 27 causes the diaphragm 1 to
9 is pressed downward as shown in FIG. Second
(see figure), the negative pressure overcomes the pressing force of the coil spring 27 and moves the diaphragm 19 toward the negative pressure chamber 25 in FIG. 1, opening the valve hole 6a. When the negative pressure in the negative pressure chamber 25 further increases and exceeds a certain value D, the diaphragm 19 is further moved toward the negative pressure chamber 25 side by the negative pressure, and the valve body 18 comes into contact with the partition wall 4 and closes the through hole 4a. , 4a... are closed.

In addition, in the figure, the reference numeral 28 is a fixed orifice provided in the second inflow path 2b.

Next, the operation of the above embodiment will be explained.

Now, when the throttle valve (not shown) is closed while the engine is running, the amount of air supplied from the intake passage (not shown) to the combustion chamber (not shown) of the engine will be reduced and the air will be incomplete in the combustion chamber. Combustion becomes more likely to occur, and as a result, the proportion of unburned components such as carbon monoxide in the exhaust gas released into the atmosphere increases, leading to air pollution.
However, in this case, the negative pressure on the downstream side of the throttle valve in the intake passage increases due to the closure of the throttle valve.
The negative pressure in the outflow passage 3 of the valve housing 1 that communicates with the downstream side of the throttle valve in the intake passage increases, first the reed valve 11 is opened, and then the negative pressure in the negative pressure chamber 25 that communicates with the downstream side of the throttle valve in the intake passage increases. When the negative pressure exceeds a predetermined value C, the diaphragm 19 is moved toward the negative pressure chamber 25 against the biasing force of the coil spring 27, and the valve body 18 is separated from the valve seat member 6 to close the valve. Hole 6a is opened.
In this state, the first and second inflow passages 2a, 2b communicate with each other via the through holes 4a, 4b... provided in the partition wall 4, so the throttle valve (not shown) of the intake passage (not shown) 1) Atmospheric air that has flowed into the inflow path 2 communicating with the upstream side flows into the valve chamber 10 through the first inflow path 2a, the atmospheric pressure chamber 26, and the through holes 4a, 4a... of the partition wall 4, and also flows into the second inflow path. Orifice 2 of road 2b
8 into the valve chamber 10, and from the valve chamber 10 into the valve hole 6a of the valve seat member 6 and the valve hole 1 of the reed valve 11.
4a into the outlet passage 3, from where it is supplied via an intake passage (not shown) to the combustion chamber (not shown) of the engine.

Further, when the negative pressure inside the negative pressure chamber 25 increases further and exceeds the predetermined value D, the negative pressure causes the diaphragm 19 to
further moves toward the negative pressure chamber 25 side, and the valve body 18 moves toward the partition wall 4.
is seated, and the through holes 4a, 4a, . . . are closed. In this state, communication between the second inflow path 2a and the valve chamber 10 is cut off, so the atmosphere flows into the valve chamber 10 through the orifice 28 of the second inflow path 2b, and from there flows into the valve holes 6a, 14a. through which it is led to the outflow channel 3. Therefore, at this time, the amount of air flowing from the inflow path 2 to the outflow path 3 is throttled by the orifice 28 and reduced to a constant value r (see FIG. 2).

(Effect of the invention) The flow control device with a reed valve according to the invention has the above-described configuration and operation, and is the only one that does not require special actuators or two or more on-off valves for opening and closing the valve. The flow rate of the fluid flowing from the inflow path to the outflow path can be variably controlled in three stages according to changes in the negative pressure in the negative pressure chamber using the individual on-off valves. In addition, since only one on-off valve is used, the number of parts is reduced compared to conventional ones, simplifying the configuration and reducing costs.
The entire device can be made compact.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view of a flow control device with a reed valve according to the present invention, Fig. 2 is a graph showing its flow characteristics, Fig. 3 is a longitudinal side view of a conventional flow control device with a reed valve, and Fig. 4 is a graph showing the flow rate characteristics. Explanation of symbols, 1...Valve housing, 2...Inflow path, 2a
...First inflow path, 2b...Second inflow path, 3...Outflow path, 4...Partition wall, 4a...Through hole, 5...Opening/closing valve, 6...Valve seat member, 6a...Valve hole , 11... Reed valve, 18... Valve body.

Claims (1)

[Scope of utility model registration request] In a flow control device with a reed valve, a reed valve is provided between an inflow path and an outflow path formed in a valve casing, and an on-off valve operated by negative pressure is provided upstream of the reed valve. The passage is divided into a first and second inflow passage by a partition wall, and the partition wall includes:
A through hole is formed at a position facing the valve hole formed in the valve seat member of the on-off valve, and a valve body of the on-off valve is disposed between the through hole and the valve hole, and the valve body allows the A flow control device with a reed valve that can selectively open and close a valve hole and a through hole.