JPS6053170B2 - pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure control device, and more particularly, to a pressure control device having two actuators, each actuator separately operable in response to a signal pressure from a different signal pressure source. Introducing signal pressure to the equipment from each signal pressure source connected to the operating equipment.
The present invention relates to a pressure control device that can switch between non-induction and non-induction.

Conventionally, this type of device has been used, for example, as shown in FIG.
Negative pressure as a signal pressure (closer to a vacuum when the vehicle is running at a constant speed, etc.) is transmitted to the exhaust gas recirculation valve device 303, which is the first operating device, via the first passage 302, and the first signal pressure is The first actuating device 303 is not opened according to the negative pressure value,
Exhaust gas is recirculated to the intake manifold 304, and negative pressure is generated as a second signal pressure in the intake manifold 304, which is a second signal pressure source located below the throttle valve 300 (when the vehicle is idling, decelerating, etc.) (closer to a vacuum) is transmitted to a secondary air supply valve device 306, which is a second operating device, via a second passage 305, and the second operating device 306 is opened in accordance with the negative pressure value of the second signal pressure. to supply secondary air to the exhaust manifold.

For example, when the engine cooling water temperature is lower than a preset temperature, it is necessary to forcibly stop exhaust gas recirculation and secondary air supply for reasons of drivability. Temperature range control valves are required, and temperature range control valves 307 and 308 are provided in the first passage 302 and the second passage 305, respectively. Both temperature range detection valves 307 and 308 are bimetallic and switch inversely depending on the temperature, so when the engine cooling water temperature is below the set temperature, they switch to the open state and introduce atmospheric air into both passages 302 and 305, respectively. When the operating devices 303 and 306 are forced to stop operating, and when the engine cooling water temperature reaches the set temperature or higher, both passages 302 and 306 are switched to the closed state.
305 by blocking the introduction of the atmosphere to each of the first signal pressure sources 3
01, the signal pressure from the second signal pressure source 304 is introduced into both operating devices 303, 306, respectively, and both operating devices 303,
306 to be operable. Therefore, in this conventional device, two actuating devices, namely the first actuating device 3
03 and the second actuating device 306, for example, by detecting the temperature and operating with a switching signal according to the detection result. Since the configuration is such that a total of two valve devices, temperature sensing valves 307 and 308 are arranged for the first operating device 302 and the second operating device 306, respectively, as valve devices that can introduce atmospheric air into the devices, two independent valve devices are provided. By arranging the temperature sensing valves 307 and 308, both sensing valves 307 and 308 are arranged.
Even if strict manufacturing control is performed to enable simultaneous operation of both sensing valves 307 and 308, there will be some deviation in the operation of both sensing valves 307 and 308, and it is impossible to eliminate the deviation in operation between both sensing valves 307 and 308. There was a drawback that it was possible.

Therefore, the present invention aims to introduce atmospheric air into and out of both operating devices that operate using signal pressures from different signal pressure sources using a predetermined switching signal.
The purpose is to obtain a pressure control device that can perform non-induction switching control at the same time. When atmospheric air is introduced or not introduced into the second operating device using a predetermined switching signal via the third passage.
First and second one-way valves are provided in the third passages between the valve apparatus and the first and second passages, respectively, and the first one-way valve extends in the direction from the valve apparatus to the first signal pressure source. such that the second one-way valve allows fluid communication only in the direction from the valve arrangement to the second signal pressure source. The gist of the configuration is that the first and second one-way valves are installed facing each other.

Therefore, with this configuration, the present invention allows atmospheric air to be introduced into and out of both operating devices using a single valve device that operates in response to a predetermined switching signal. In addition to achieving the initial objective of controlling the introduction and non-induction of atmospheric air and simultaneously switching the operation of both operating devices without causing a lag in the switching control timing between the two operating devices, the valve device and the In the third passage between the two passages, the first
, a second one-way valve is provided, and the first and second one-way valves are oriented to face each other so as to allow fluid communication only in the direction from the valve device to the first and second signal pressure sources, respectively. Therefore, regardless of whether the signal pressure is positive pressure or negative pressure, the operation of the one-way valve causes the signal pressure to be applied to the first signal pressure of the first operating device, to the second operating device side, or to the second operating device side. This provides an excellent effect of preventing signal pressure from entering the first operating device. Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an example in which a pressure control device according to the present invention is applied to exhaust gas purification control of a vehicle or the like.

Reference numeral 10 designates a temperature sensing valve as a valve device detailed in FIG. 2, which is connected to a one-way valve body 12 via a conduit 11 as a third passage.

The valve body 12 is connected to an advance port 1 which is a first signal pressure source generated in accordance with the displacement of the throttle valve 13 of the carburetor.
4 and the negative pressure at the intake manifold 15, which is a second signal pressure source, are received as input signals through a pipe line 16 as a first passage and a pipe line 17 as a second passage, respectively, and are connected to a one-way valve. body 1
The outputs of 2 control the secondary air supply to the exhaust gas recirculation control valve 20 and the exhaust manifold, which are the first operating devices, through the pipe 18 as the first passage and the pipe 19 as the second passage, respectively. The air switching valve 21 is connected to an air switching valve 21, which is a first actuating device. The exhaust gas recirculation valve 20 is located between the intake manifold and the exhaust manifold, and is located between the body 22
Three chambers 25, 26 and 27 are formed therein by a diaphragm 23 and a partition wall 24.

The first chamber 25 communicates with the conduit 18 to constitute a signal pressure chamber,
The second chamber 26 constitutes an atmospheric pressure chamber, and the third chamber 27 is connectable via a line 28 to an exhaust manifold and via a line 29 to an intake manifold. The lower end of the piston 30, which operates integrally with the diaphragm 23, constitutes a valve section 31 that opens and closes the pipe line 28, so that the negative pressure in the signal chamber 25 overcomes the spring 32, and the diaphragm 23 and the piston having the valve section 31 are closed. 30 is moved upward in the figure, the pipes 28 and 29 are communicated, and as is well known, part of the exhaust gas is recirculated from the exhaust manifold to the intake manifold, thereby reducing nitrogen oxides in the exhaust gas. do. The air switching valve 21 described above is connected to the air pump 3.
A diaphragm 37 is disposed within the body 36 between a pipe line 34 connected to the exhaust manifold and a pipe line 35 leading to the exhaust manifold.
Three chambers 39, 40, and 41 are formed by the partition wall 38 and the partition wall 38.

The first chamber 39 communicates with the conduit 19 to constitute a signal pressure chamber,
The second chamber 40 constitutes an atmospheric pressure chamber, and the third chamber 1 is capable of communicating with conduit 34 to receive air pump pressure and is connected to conduit 35.
Connects to the exhaust manifold via. diaphragm 3
The lower end of the piston 42 that operates integrally with the diaphragm 37 and the valve portion 43 constitutes a valve portion 43 that opens and closes the conduit 34 . By displacing the piston 42 upward in the figure, connecting the pipes 34 and 35, and injecting air pump pressure into the exhaust manifold, the well-known air injection function acts to oxidize CO, HC, etc. in the exhaust gas. Temperature sensing valve 10 includes first, second and third portions 46, 46 secured together as detailed in FIG.
, 47, and a thermostat bimetal 48 that detects temperature changes and changes its curvature is disposed within the housing.

When the bimetal 48 is in the position shown in FIG.
An atmospheric boat 50 is connected to a boat 51 which communicates with the conduit 11 at a distance from the atmospheric boat 50 . When the temperature sensed by the bimetal 48 rises above a predetermined value, the bimetal 48, which is convex to the right in FIG. The communication between the boats 50 and 51 is then cut off. The bimetal 48 is positioned by a spring 52, and in the illustrated state, its outer periphery is in contact with the shoulder 53 of the first portion 45. Incidentally, the temperature sensing valve 10 is connected to the first portion 4.
6 is screwed into an appropriate position, for example, inside the water jacket of the engine. The aforementioned positional valve body 12 includes first, second, third, and fourth portions 55, 56 that are secured to each other as detailed in FIG.
, 57, 58.

The first portion 55 has a boat 59 communicating with the conduit 16 and a boat 60 communicating with the conduit 18, and an orifice 61 is provided between the boats 59 and 60. fourth part 58
, boats 62 and 63 are connected to the pipes 17 and 19, respectively.
An orifice 64 is provided between both boats 62 and 63.
is provided. A boat 65 communicating with the conduit 11 is provided in the third portion 57 . The boat 65 is the second part 56
It is possible to communicate with the boats 60 and 63 through one-way valves 66 and 67 disposed above, respectively, and the one-way valves 66 and 6
7 have holes 68, 69 disposed in the second portion 56 and elastic valve bodies 70, 71, respectively. In addition, the one-way valve 66
, 67 in the open state, the boat 65 and the boat 59 or 62
Fluid communication with is restricted by orifices 61,64. The pressure control device configured as described above operates as described above.

When the temperature sensed by the temperature sensing valve 10 is below a predetermined value, the bimetal 48 is in the position shown in FIG. The atmosphere reaching the boat 65 opens the valve bodies 70 and 71 of the one-way valves 66 and 67, and the boat 60
, 63 to convey the atmosphere.

Atmospheric air is introduced into the signal pressure chambers 25, 39 of the exhaust gas recirculation control valve means 20 and the air switching valve 21 via the exhaust gas recirculation control valve means 20 and the air switching valve 21 via the exhaust pipes 18, 19, respectively, and the valve parts 31, 43 are connected to the pipes 28, 19, respectively. Close 34. In such conditions, exhaust gas recirculation and air injection are therefore not achieved, regardless of the operating state of the engine. Now, when the bimetal 48 of the temperature sensing valve 10 senses a temperature higher than a predetermined value, the bimetal 48 reverses its curvature and
9 and isolates the atmospheric boat 50 from the boat 51.

Therefore, the signal pressures for both valves 20, 21 are switched and controlled simultaneously. In other words, the negative pressure generated in the adpan port 14 of the carburetor is transmitted to the signal pressure chamber 25 of the control valve 20 via the pipe 16, the boats 59 and 60 of the one-way valve body 12, and the pipe 18. Therefore, when the negative pressure at the advance port 14 is large, such as when the vehicle is running at a constant speed, the piston 30 having the diaphragm 23 and the valve portion 3J1 is moved by the spring 3.
2, the pipes 28, 29 are displaced upwardly in FIG.
A portion of the exhaust gas from the exhaust manifold is recirculated to the intake manifold. At the same time, it is recirculated to the intake manifold. At the same time, the negative pressure of the intake manifold 15 is transmitted to the signal pressure chamber 39 of the air switching valve 21 via the pipe line 17, the boats 62 and 63 of the one-way valve body 12, and the pipe line 19, so that when the vehicle is idling, When the negative pressure is large enough in the intake manifold 15, such as during deceleration,
The piston 42 having the diaphragm 37 and the valve portion 43 is displaced upward in FIG.
4 and 35 are communicated to achieve air injection action. When the temperature sensed by the temperature sensing valve 10 described above is equal to or higher than a predetermined value, for example, the intake manifold 1 is used as the second signal pressure source.
The negative pressure of 5 is applied to the advance port 14 as the first signal pressure source.
In other words, the pressure generated at the advance port 14 as the first signal pressure source is always higher than the negative pressure at the intake manifold 1 as the second signal pressure source.
5 (closer to atmospheric pressure), the valve body 70 of the one-way valve 66 is held closed, stopping the flow of gas from the advance port 14 to the intake manifold 15. Both signal pressures will not mix.

Conversely, if the negative pressure of the second signal pressure source is always higher than the negative pressure of the first signal pressure source (close to atmospheric pressure), the one-way valve 67 The valve body 71 is held in a closed state to stop the flow of gas from the intake manifold 15 to the advance port, thereby preventing the two signal pressures from mixing.
Therefore, even if the height relationship of the first signal pressure source (intake manifold 15) changes depending on the operating condition of the engine, both signal pressures can be maintained by the action of the two one-way valves installed in opposite directions. Contamination with sources can be prevented. Fourth
The figure shows a switching valve body 100 as a valve device that may be disposed in the apparatus of FIG. 1 in place of the temperature sensing valve 10 in FIG.

The valve bodies 100 are arranged so as to sandwich the outer periphery of the diaphragm 101. The first and second bodies 102, 10 are fixed to each other.
3, and the first body 102 is provided with a signal boat 105 connected to the throttle positioner port 104 shown in FIG. Therefore, when the signal negative pressure in the chamber 106 connected to the boat 105 overcomes the biasing force of the spring 107, the swinging members 108 and 116 disposed on the diaphragm 101 move to the left in the figure, and the The valve member 109 that is attached to the seat 1 of the second body 103
Separate from 10. Therefore, it is separated from the seat 110 of the second body 103. Therefore, the fair is sent to the boat 117 leading to the conduit 11 in FIG. Operating equipment 2
Switching control between introducing and not introducing the atmosphere to 0 and 21 is performed at the same time. When the vehicle is generally running, the negative pressure at the throttle positioner port 104 is smaller than the set value (closer to atmospheric pressure), and the valve 109 abuts and engages the seat 110. The negative pressure of the exhaust gas recirculation control valve means 20 is transmitted to the signal pressure chamber 25, and at the same time the negative pressure of the intake manifold 15 is transmitted to the signal pressure chamber 39 of the air switching valve 21, which controls the exhaust gas recirculation and air injection. will be done. Also, when the vehicle is decelerating or idling, the throttle valve 13 closes, so the negative pressure at the throttle positioner port 104 is greater than the set value (closer to a vacuum), and the valve 109 closes to the seat 110. Since the exhaust gas recirculation control valve means 20 and the air switching valve 21 are separated from each other, atmospheric air is introduced into the signal pressure chambers 25 and 29 of the air switching valve 21, respectively.
Both exhaust gas recirculation and air injection stop. Therefore, afterburn during vehicle deceleration is prevented, and engine stability during idling is ensured.
Figures 5 and 6 show further embodiments.

In this embodiment, parts that are substantially similar to those in FIG. 1 are designated by the same numerals. In this embodiment, positive exhaust gas pressure is used as the first signal pressure of the exhaust gas recirculation control valve 20, and positive air pump pressure is used as the second signal pressure of the air switching valve 21. This is different from the previous embodiment. In case of clogging, the pipe line 28 from the exhaust manifold reaches the one-way valve body 12 via the pipe line 200, and further reaches the exhaust gas pressure chamber 202 of the control valve 20 via the pipe line 201. Note that the chamber 203 that accommodates the spring 32 constitutes an atmospheric pressure chamber. on the other hand,
A pipe line 204 branching from the pipe line 34 reaches the air pump chamber 206 of the air switching valve 21 via the one-way valve body 12 and the pipe line 205. Chamber 20 housing spring 44
7 constitutes an atmospheric pressure chamber. In addition, by using positive pressure as the signal pressure as described above, the one-way valves 208 and 29 of the one-way valve body 12 are located on the opposite side of the holes 210 and 211 from the previous embodiment. It has valves 212 and 213. In this embodiment, the bimetal having the same structure as the temperature sensing valve 10 shown in FIG. The pressure forces valves 212, 214 apart and is released to the atmosphere.

Therefore, the valve portion 31 of the control valve 20 and the switching valve 21
The valve portions 43 are biased to the closed position by springs 32 and 44, respectively, so that no exhaust gas recirculation or air injection is achieved. When the sensed temperature exceeds a predetermined value and the bimetal abuts and engages with the O-ring, the conduit 11 is cut off from the air hole.

Therefore, when the exhaust gas pressure transmitted to the chamber 202 of the control valve 20 overcomes the spring 32, the valve part 31 is displaced into the open position and exhaust gas recirculation is achieved. On the other hand, when the air pump pressure reaching the chamber 206 of the switching valve 21 overcomes the spring 44, the valve portion 43 is displaced to the open position and air is injected. In the above state, since the air pump pressure as the second signal pressure is always set higher than the exhaust gas pressure as the first signal pressure, the one-way valve 212
is held in a closed state, the flow of gas from the air pump side to the exhaust manifold side is stopped, and mixing of both signal pressures can be prevented. Therefore, even if the height relationship between the first signal pressure and the second signal pressure changes depending on the operating condition of the engine, the two one-way valves installed in opposite directions prevent the two signal pressures from mixing. can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a fluid control device according to the present invention, FIG. 2 is a detailed sectional view of the temperature sensing valve of FIG. 1, FIG. 3 is a detailed sectional view of the one-way valve body of FIG. 1, and FIG. 4 is a detailed sectional view of the one-way valve body of FIG. Fig. 5 is a cross-sectional view of a modified switching valve device that can be applied to the device shown in Fig. 1, Fig. 5 is a similar view to Fig. 1 showing a further modification, and Fig. 6 is a detailed cross-section of the one-way valve body shown in Fig. 5. It is a diagram. 10... Temperature sensing valve (valve device), 12...
・One-way valve body, 13... Throttle valve, 1
4...Advance port (first signal pressure source), 1
5... Intake manifold (second signal pressure source), 2
0...Exhaust gas recirculation control valve (first operating device)
, 21... Air switching valve (second operating device), 66, 67... One-way valve.

Claims (1)

[Claims] 1. A first operating device for an exhaust gas purification device comprising a first signal pressure source that changes according to the operating state of the engine, a diaphragm actuator that operates according to the first signal pressure of the first signal pressure source, and the first operating device for an exhaust gas purification device. a first passage connecting a signal chamber of one operating device and the first signal pressure source; a second signal pressure source that varies depending on the operating state of the engine and is different from the first signal pressure source; and the second signal pressure. a second operating device for an exhaust gas purification device comprising a diaphragm actuator that operates in response to a second signal pressure of a source; a second passage connecting a signal chamber of the second operating device with the second signal pressure source; a third passage connecting an atmospheric source to the first and second passages; a third passage disposed in the third passage; introducing atmospheric air from the atmospheric source to the first and second passages in response to a predetermined switching signal; the first and second one-way valves respectively disposed in the third passage between the valve apparatus and the first and second passages; A one-way valve allows fluid communication only in the direction from the valve device to the first signal pressure source, and a second one-way valve allows fluid communication only in the direction from the valve device to the second signal pressure source. so as to permit said first,
A pressure control device, wherein the second one-way valves are installed in opposite directions.