JPH0128221B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust gas recirculation amount control valve in an engine, and more particularly, to an exhaust gas recirculation amount control valve for an engine, and more particularly, to a control device that partitions an atmospheric pressure chamber and a negative pressure chamber by a partition, and controls the amount of operation of the partition. The present invention relates to an exhaust gas recirculation amount control valve that is provided with a valve body that controls the flow area of the exhaust gas recirculation passage in conjunction with a partition that is operated by adjusting the pressure in the negative pressure chamber by the control means. It is preferably used for NOx control in diesel engines, gasoline engines, etc. (Hereinafter, this will be referred to as an EGR valve.) Conventionally, a solenoid has been used to adjust the negative pressure of this type of EGR valve. However, this type of electrical control does not directly detect the engine load, but instead converts it into an electrical signal, which requires a control device to send this signal to the EGR valve, resulting in a complicated structure. Not only that, but they were also prone to breakdowns. Furthermore, since the control is only indirect, there is a drawback that there is no certainty in adjusting the amount of exhaust gas recirculation relative to the load.

SUMMARY OF THE INVENTION An object of the present invention is to provide an EGR valve for an engine that can reliably adjust the amount of exhaust gas recirculation depending on the load, has a simple structure, and is less prone to failure, in order to eliminate such drawbacks.

Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings. 1 is a valve seat 4 in which an inlet 2 at the lower end and a discharge outlet 3 that is perpendicular to the inlet 2 are connected to a valve seat 4 within the inlet 2. This is a valve box that communicates with the intake port 2 and the discharge port 3 through the exhaust gas recirculation passage 1a. 5 was installed adjacent to the same valve box 1.
In the control unit body of the EGR valve, 6 is a partition portion in which the inner circumference of a ring-shaped diaphragm 7 is clamped by a pair of upper and lower clamping plates 8 and 9, and these clamping plates 8 and 9 can be separated. and a diaphragm 7 made of rubber etc.
The outer periphery of the controller body 5 is clamped to the inner periphery of the control unit body 5, and the inside of the body 5 is divided into upper and lower chambers 10 and 11.

The pressure regulating mechanism is constructed as follows. Reference numeral 12 denotes a valve hole provided through the center of the upper clamping plate 8 of the partition portion 6, and a valve seat 13 is formed at the upper end thereof facing downward. 14 is a valve device normally seated on the valve seat 13 by the bias of a spring 15 supported on the substantially central portion of the lower clamping plate 9 of the partition portion 6; It is a ring-shaped filter that is clamped between the upper and lower clamping plates 8 and 9, and a filter chamber 17 is formed on the inner and outer peripheries of the ring-shaped filter, and a filter chamber 17 is formed between the valve hole 12 of the upper clamping plate 8 and the filter chamber 1.
7 is connected.

Reference numeral 18 denotes a valve body provided downward from approximately the center of the lower clamping plate 9 of the partition portion 6, and is moved up and down by a guide 19 provided at the connecting portion between the valve box 1 and the control body 5. The upper chamber 10 of the control body 5 is inserted into the valve body 1 while being guided so as to bias the upper clamping plate 8 of the partition 6 downward.
It is normally seated against a valve seat 4 within the valve body 1 by a spring 20 supported therein.

Reference numeral 21 denotes a plurality of openings transparently provided in the lower part of the control unit body 5, and the lower chamber 11 in the body 5.
is communicated with the atmosphere to make the lower chamber 11 an atmospheric pressure chamber. Reference numeral 22 denotes a plurality of communication holes transparently provided in the lower clamping plate 9 of the partition section 6, which are connected to the atmospheric pressure chamber 1.
1 and the filter chamber 17 are communicated with each other.

Reference numeral 23 is a conduit connected to the upper chamber 10 of the control section body 5, and by communicating this to a negative pressure source, the upper chamber 10 is made into a negative pressure chamber.

Note that the communication hole 22, the filter chamber 17, and the valve hole 12 form an atmospheric passage 6a that communicates the atmospheric pressure chamber 11 and the negative pressure chamber 10.

Reference numeral 24 denotes a control mechanism provided at the upper part of the control body 5, and a spring 27 at the upper part of the body 25 urges the movable element 26 downward to move the lower rod part 26a into the partition part 6. Valve device 1
4, and the wire 2 is attached to the upper part of the movable element 26.
8 are connected to guide the wire 28 to the outside of the body 25, and the negative pressure chamber 10 is sealed by the sealing material 29 connected between the mover 26 and the body 25.
9 It is cut off from the atmosphere above.

Next, the operation of the EGR valve configured as described above will be explained.

When a controller (not shown) controls the wire 28 to be pulled upward in a state where negative pressure is introduced into the negative pressure chamber 10, the movable element 26 is pulled upwardly by the wire 28.
As the pulling force is pulled up to a position where it is balanced with the elastic force of the spring 27, the valve body 18 becomes a partition that moves upward against the bias of the spring 20 due to the pressure difference between the negative pressure chamber 10 and the atmospheric pressure chamber 11. 6, the valve seat 4 in the valve box 1 opens and the suction port 2
and the discharge port 3 communicate with each other.

When the valve device 14 comes into contact with the rod portion 26a of the movable element 26, the valve device 14 lowers against the bias of the spring 15, and the valve seat 13 opens. Then, atmospheric pressure chamber 1
1. Since the atmosphere is introduced into the negative pressure chamber 10 through the communication hole 22, the filter chamber 17, and the valve hole 12, the negative pressure in the negative pressure chamber 10 decreases, and the partition part 6 is biased by the spring 20. The valve device 14 moves downward to the valve seat 1.
3 closes, the valve seat 4 in the valve body 1 also closes the valve body 1.
Closed by 8.

When the valve seat 13 is closed and the negative pressure in the negative pressure chamber 3 increases again, the partition portion 6 moves upward and the valve body 18 opens the valve seat 4.

Therefore, if the amount of pull of the wire 28 is changed,
Since the vertical position of the mover 26 also changes, the valve body 18 connected to the partition part 6 also displaces in the same way as in the case described above, following this vertical movement amount, and the movement amount of the valve body 18, that is, the exhaust gas recirculation passage. The flow path area of 1a can be controlled.

Next, an application example of the EGR valve A according to the present invention will be explained.

FIG. 2 shows an embodiment applied to a diesel engine, in which the exhaust gas recirculation passage 1a of the EGR valve A is used as an exhaust gas recirculation passage that communicates the intake pipe 31 and the intake pipe 32 of the internal combustion engine 30, and the EGR valve A The conduit 23 is connected to a vacuum pump (not shown) via a vacuum switching valve 33 and a vacuum tank 34, and is connected to a wire 28 of the EGR valve A.
is linked to a speed control lever 36 (mechanical operating mechanism) of the fuel injection pump 35.
Note that it is also possible to use a brake vacuum pump instead of the vacuum pump.

As mentioned above, the opening degree of the exhaust gas recirculation passage 1a of the EGR valve A increases as the amount of pull of the wire 28 increases, but the amount of pull can be adjusted by using the accelerator pedal (which operates the speed control lever 36). (not shown). The amount of depression of the accelerator pedal, that is, the operating weight of the speed control lever 36, is inversely proportional to the amount of pulling of the wire 28, that is, the degree of opening of the exhaust gas recirculation passage 1a.

In other words, the operating range where exhaust gas recirculation is unnecessary (for example,
During idling (as indicated by L in Figure 3),
The vacuum switching valve 33 is closed.
Since the negative pressure supplied to EGR valve A is cut off,
The exhaust gas recirculation passage 1a is closed and the amount of exhaust gas recirculation becomes zero.

When the load increases beyond this idling region L, the vacuum switching valve 33
opens and negative pressure is supplied to the EGR valve A, so the exhaust gas recirculation passage 1a opens and the exhaust gas recirculation amount reaches its maximum. After that, the amount of exhaust gas recirculation becomes smaller, contrary to the opening degree of the fuel injection pump 35 depending on the operating amount of the speed control lever 36.

FIG. 4 shows an example in which the EGR valve A is applied to a gasoline engine, and compared to the case of the diesel engine described above, the conduit 23 of the EGR valve A is connected to the intake pipe 3 through a vacuum switching valve 33.
The difference is that the wire 28 of the EGR valve A is connected to the throttle lever 37 (mechanical operating mechanism) of the carburetor by communicating with the EGR valve A and utilizing its negative pressure. The amount of depression of the accelerator pedal (not shown), that is, the amount of operation of the throttle lever 37 is determined by the wire 28.
It is designed to be proportional to the amount of pull, that is, the opening degree of the exhaust gas recirculation passage 1a.

That is, at the time of idling, which is indicated by L in FIG. 5, the amount of exhaust gas recirculation is zero, as in the case of a diesel engine. When the load increases beyond this idling region L, the vacuum switching valve 33 opens and negative pressure is supplied to the EGR valve A, so the exhaust gas recirculation passage 1a opens and the amount of exhaust gas recirculation begins to increase. Thereafter, the amount of exhaust gas recirculation increases in proportion to the opening degree of the throttle lever 37.

In the above embodiment, the speed control lever 36 and the throttle lever 37 are controlled by the control mechanism 24.
Although the wire 28 is used as a mechanical interlocking means for interlocking the movement, a link mechanism may be used instead.

As detailed above, the EGR valve according to the present invention includes a control mechanism and a pressure regulating mechanism as control means,
An atmospheric passage 6a in which a valve device 14 is interposed as the pressure regulating mechanism is provided in the partition portion 6, and the valve device 1
4 is provided with a valve seat 13 and a mover 26 having a rod portion 26a for opening and closing the valve seat 13, and the control mechanism is linked to mechanical operating mechanisms 36 and 37 that are directly related to the engine load. It is characterized in that a mechanical interlocking means 28 for moving the movable element 26 forward and backward is provided on the negative pressure chamber side. Therefore, the displacement of the mechanical operating mechanisms 36, 37 is controlled by the mechanical interlocking means 2.
Since this is directly transmitted to the EGR valve A as a displacement of 8, the amount of exhaust gas recirculation can be reliably adjusted to the load, the structure is simple, and failures are eliminated.

In addition, since the atmospheric passage 6a in which the valve device 14 is interposed as a pressure regulating mechanism is provided in the partition portion 6, the control mechanism 24
The movable parts of the motor can be greatly simplified and lightened, and the responsiveness can be significantly improved. This means that even though the mechanical movement mechanism 3
There is almost no burden on 6 and 37, and there is no adverse effect on the original operation.

Incidentally, when the wire 28 is used as the mechanical interlocking means, the structure becomes very simple.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the exhaust gas recirculation amount control valve according to the present invention, Fig. 2 is a system diagram showing an embodiment in which the exhaust recirculation amount control valve of the present invention is applied to a diesel engine, and Fig. 3 is its EGR rate. FIG. 4 is a system diagram showing an embodiment in which the exhaust gas recirculation amount control valve of the present invention is applied to a gasoline engine, and FIG. 5 is an EGR rate diagram thereof. Valve box...1, Exhaust recirculation passage...1a, Valve seat...
4. Control unit body...5, Partition section...6, Atmospheric passage...6a, Clamping plate...8,9, Negative pressure chamber...1
0, Atmospheric pressure chamber...11, Valve seat...13, Valve device...
...14, Filter...16, Valve body...18, Communication hole...22, Control mechanism...24, Mover...2
6. Rod part...26a, Wire (mechanical interlocking means)...28, Speed control lever (mechanical operating mechanism)...36, Throttle lever (mechanical operating mechanism)...37, EGR valve...A .

Claims (1)

[Scope of Claims] 1. The inside of the control unit body is divided into an atmospheric pressure chamber and a negative pressure chamber by a partition, and has a control means for controlling the operating amount of the partition, and the control means controls the negative pressure. An exhaust gas recirculation amount control valve including a valve body that controls the flow area of an exhaust gas recirculation passage in conjunction with a partition that is activated by adjusting the indoor pressure, wherein the control means includes a control mechanism and a pressure regulating mechanism. , an atmospheric passage through which a valve device is interposed as the pressure regulating mechanism is provided in the partition, and the valve device is provided with a valve seat and a movable member having a rod portion for opening and closing the valve seat, An exhaust gas return system for an engine, characterized in that the control mechanism is provided with a mechanical interlocking means on the negative pressure chamber side for moving the mover forward and backward in conjunction with a mechanical operating mechanism directly related to the load of the engine. Flow control valve. 2. The exhaust gas recirculation amount control valve in an engine according to claim 1, wherein the mechanical interlocking means is a wire.