JPS6153541B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid control valve, and more particularly to an improvement in a fluid control valve used in an exhaust gas purification system for an internal combustion engine. In general, a fluid control valve device refers to a diaphragm-driven valve that controls the operating pressure of devices etc. using signal pressure. Conventional fluid control valve devices, especially air bleed type negative pressure control valves, are used to purify exhaust gas. The system detects signal pressures such as intake manifold negative pressure, throttle opening port negative pressure, and air pump pressure, and bleeds (introduces) air into the pressure circuit that connects the fluid pressure source and various devices by opening and closing valves. It was something that made me want to do something. However, as shown in Figure 1, its characteristics are such that the ratio of Po to input pressure Pi is set to Po/Pi = 1 by the pressure signal.
It was intended to switch Po/Pi=0. In other words, Po/Pi = 1 indicates that the input pressure becomes the output pressure when the valve is closed, and Po/Pi = 0 indicates that the atmosphere is introduced when the valve is open and the output pressure becomes the output pressure. This indicates that the pressure is at atmospheric pressure, and therefore the ratio of output pressure to input pressure cannot be arbitrarily selected.

In addition, as a valve device for controlling the opening and closing of a fluid passage connecting a fluid pressure source and a servo means, JP-A-51
- The one described in Publication No. 60831 is known. However, in this valve device as well, the ratio of output pressure Po to input pressure Pi is Po/Pi.
It is not possible to arbitrarily set the ratio of output pressure to input pressure by simply controlling the switching between = and Po/Pi = 0. Therefore, its application to various exhaust gas purification systems has been limited.

Therefore, an object of the present invention is to open and close a valve that senses signal pressure and operates as shown in FIG.
The ratio of output pressure to input pressure is Po/Pi=1.
The purpose is to control the switching so that Po/Pi=0 and to arbitrarily set the output pressure ratio with respect to the input pressure.

In order to achieve the above object, the basic configuration of the present invention is to connect an atmospheric source through an orifice between an input port and an output port when a valve is opened. At this time, by changing the size of the orifice, the ratio of input pressure to output pressure can be arbitrarily determined.

The present invention will be explained below based on an embodiment in which the present invention is applied to an engine ignition timing adjustment system with reference to the attached FIGS. 3, 4, and 5.

As is well known, the ignition timing adjustment system detects vehicle conditions, such as vehicle speed and water temperature, and sets the optimal ignition timing for each.
This is a system that aims to reduce CO and NO _x , maintain driving performance, and reduce fuel consumption.

10 is a fluid control valve device, and housing 11
consists of a first section 12, a second section 13 and a third section 14, and the second
The first section 12 and the third section 14 are hermetically secured to the section 13 by appropriate means. The screw 15 disposed on the inner peripheral portion 12a of the first section 12 has an adjuster screw 16.
One end of the adjusting screw 16 locks a thrust washer 17, and the other end is filled with silicone rubber 18, which prevents reverse rotation of the adjusting screw 16 and prevents the adjusting screw 16 from rotating backwards. It functions to seal the threaded portion between the unit 16 and the screw 15. A spring 19 is disposed inside the first section 12, one end of which is engaged with the thrust washer 17, and the other end of the spring 19 urges the sliding member 20 to the right in the drawing. By adjusting the adjustment screw 16, the mounting load of the spring 19, that is, the rightward biasing force in the drawing against the sliding member 20 can be adjusted within a certain range. The diaphragm 21 has an inner part 21a fixed to the sliding member 20 and a fixed member 22 and the sliding member 20.
The outer periphery 21b is clamped between the first section 12 and the second section 13.
The interiors of the first and second sections 12 and 13 are separated by a sliding member 20 and a diaphragm 21 into a first chamber 23 that accommodates a spring 19 and a second chamber 24 that accommodates a valve to be described later. be done.
The first chamber 23 serves as a negative pressure chamber connected to a signal negative pressure source, such as an intake manifold 27, via a signal port 25 and a conduit 26 provided in the first section 12. The second chamber 24 is the second section 1
Air filter 29 supported by support 28 inserted into section 3, fluid introduction passage 30 disposed in second section 13, fluid introduction port 31 disposed in third section 14, and air source through pipe line 32 That is, it is connected to the air cleaner 33. Therefore, in the second chamber 24, the O-ring 34 inserted into the joint between the fluid introduction passage 30 and the fluid introduction port 31 constituting the atmospheric chamber provides a seal between the fluid introduction passage 30 and the fluid operating passage described below. Secured. A valve 36 is provided in the atmospheric chamber 24, and the valve 35
is normally biased to its open position by spring 19 and biased to its closed position by spring 36 when the negative pressure in first chamber 23 becomes a counterforce greater than the biasing force of spring 19. The valve is engageable with the seat portion 37a of the seat member 37 fixed to the second section 13, thereby controlling the opening/closing of the connection between the atmospheric chamber 24 and the fluid introduction passage 38 disposed in the second section. . The fluid introduction passage 38 is connected via a first orifice 39 provided in the passage 38 to a fluid operating passage 40 formed by fixing the second section 13 and the third section 14 together. The fluid operating passage 40 is the third
A second orifice 42 provided in a boulder 41 fixed to the section 14, an air filter 43 supported by the holder 41, and a third section 1
4 is connected to an input negative pressure source that generates a negative pressure source in response to changes in the opening degree of the throttle valve 46, that is, an advance port 48 of a well-known capretor 47. . At the same time, the fluid operating passage 40 is connected to an air filter 50 supported by a support 49 inserted into the third section 14, an output port 51 disposed in the third section 14, and a negative pressure operating device or device (not shown) via a conduit 52. It is connected to a servo means 53 connected to the ignition timing adjustment plate of the tributator. The servo means 53 is biased by a spring 54 and has a diaphragm piston 55 for controlling the operation of the ignition timing adjustment plate.

The operation of an embodiment applied to the fluid control valve device ignition timing adjustment system constructed as described above will now be described.

This embodiment has a configuration in which the fluid control valve device of the present invention is disposed in the negative pressure circuit between the vacuum advance servo means 53 of the distributor of the ignition timing adjustment system and the advance port 48 of the carburetor 47. It's summery.

In general, the ignition timing adjustment system uses a governor advance device (advance angle relative to the rotation speed) and a vacuum advance device (advance angle relative to the intake manifold vacuum), since the optimal ignition timing varies depending on the engine rotation speed and intake manifold vacuum. ) is provided. NO _x emitted from the engine
The vacuum advance angle is cut or delayed in a high load state during acceleration where there is a lot of noise, and the vacuum advance angle is normally performed in a low load state during steady running.

Now, in the high load state during the above-mentioned acceleration, the manifold vacuum is lowered, and the first chamber 23 has a vacuum weaker than the rightward biasing force of the spring 19, and the valve 35 is maintained in the open position. At this time, the manifold vacuum of the advance port 48 generated by stepping on the throttle valve 46 is as follows: input port 44 → second orifice 42 → fluid operating passage 40 → output port 51 → servo means 5
However, since the valve 35 is in the open position, the atmosphere controlled by the first orifice 39 is introduced from the air cleaner 33 into the fluid operation passage 40 via the atmosphere introduction port 31 and the fluid introduction passage 38 ( bleed), the vacuum is reduced and transmitted to the servo means 53. That is, Po／Pi≠
1, and in this example Po/Pi<
1. As a result, the vacuum advance angle of the distributor is felt and the advance angle amount is reduced. The rate at which this vacuum advancement angle decreases depends on the sizes of the first and second orifices 30 and 42. Now, if the size of the orifice 42 on the input port 44 side is kept constant and the size of the orifice 39 on the air introduction side is increased, for example, the amount of air bleed will increase and the rate of decrease in the advance angle will increase, and if the size is made smaller. Then, the amount of air bleed decreases and the rate of decrease in the advance angle becomes small.

Next, in a low load state during steady running, the manifold vacuum rises and when the first chamber 23 reaches the vacuum where it overcomes the biasing force of the spring 19, the valve 35 is maintained in the closed position. At this time, the atmospheric chamber of the second chamber 24 and the fluid introduction passage 38 are cut off, and the manifold vacuum connected to the advance port 48 is transferred from the input port 44 to the servo means 35 via the output port 31 without being reduced by the atmosphere. communicated. That is, the case where Po/Pi=1 is shown. As a result, the vacuum advance angle of the distributor is performed normally.

As described above, the fluid control valve device in the ignition timing adjustment system according to the present invention has an orifice in the negative pressure circuit for vacuum advance between the advance port of the carburetor and the servo means of the distributor during acceleration. Ignition timing is retarded by introducing controlled atmospheric air (bleed) to reduce negative pressure. As a result, an excellent effect can be obtained in that the emission of NO _x in exhaust gas can be significantly reduced. At this time, the reduction rate of the negative pressure in the vacuum advance negative pressure circuit is controlled by the sizes of the first and second orifices and can be arbitrarily determined.
This has the excellent advantage that the degree of advance of the ignition timing can be arbitrarily determined.

Furthermore, since it is formed as a single assembly, it is extremely compact. Therefore, when applied to various exhaust gas purification systems, etc., it is extremely easy to install, does not take up much space, and has the effect of simplifying the system.

As explained above, in this embodiment applied to an ignition timing adjustment system, the valve opens when the signal pressure is below a predetermined negative pressure, and the bleed fluid at that time is atmospheric air. It is easily possible to consider that the valve opens under or under positive pressure and the bleed fluid is then under positive or negative pressure, and the fluid control valve device according to the invention can be used in other exhaust gas purification systems, e.g. during engine operation. Exhaust gas recirculation systems that control the amount of exhaust gas recirculated from the exhaust system to the intake system depending on the engine operating conditions, secondary air supply systems that control the amount of air supplied to the exhaust system depending on the engine operating conditions, etc. It can also be applied as a control valve device.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the relationship between input pressure Pi and output pressure Po in a conventional air bleed type negative pressure control valve, and Fig. 2 is an explanatory diagram of the relationship between input pressure and output pressure in the fluid control valve device of the present invention. Figure 3 is a system diagram showing an embodiment of the present invention applied to an ignition timing adjustment system, Figure 4 is an enlarged sectional view of the fluid control valve device of the present invention in Figure 3, and Figure 5 is a system diagram showing an embodiment of the present invention applied to an ignition timing adjustment system. The AA cross-sectional view in Figure 4 is shown. 10...Fluid control valve device, 19...Spring, 21...Diaphragm, 25...Signal port, 2
7... Intake manifold, 30, 38... Fluid introduction passage, 31... Fluid introduction port, 33... Air cleaner, 35... Valve, 39... First orifice, 4
0...Fluid operation passage, 42...Second orifice, 44
...Input port, 47...Carburetor, 48...Advance port, 51...Output port, 53...Servo means.

Claims (1)

[Claims] 1 A liquid working passage having an input port connected to an input negative pressure source and an output port connected to a negative pressure actuation device, a fluid introduction port connected to the fluid working passage at one end and connected to an atmospheric source at the other end. a fluid introduction passage having a fluid introduction passage, a fluid control means provided in the fluid introduction passage to control opening and closing of the fluid introduction passage, a first fluid introduction passage provided between a connecting portion of the two fluid passages and the fluid control means; an orifice, a second orifice provided between the connecting portion and the input port, and a signal port for connecting the fluid control means to the signal negative pressure source, and the fluid control means includes the signal negative pressure source. A diaphragm operated by the pressure of the signal negative pressure source, a valve operated by the diaphragm, and a spring that opposes the pressure of the signal negative pressure source and determines the displacement position of the diaphragm, and the pressure of the signal negative pressure source reaches a predetermined value. When this happens, the valve of the fluid control means opens and closes, and the opening and closing operation of the valve controls the connection between the atmospheric source and the fluid operating passage, and at the time of the connection, the first
Due to the throttling action of the orifice and the second orifice, the pressure of the input negative pressure source is reduced or increased and is transmitted from the input port to the output port of the fluid working passage. Fluid control valve device for internal combustion engine exhaust gas purification system.