JPH06241071A - Exhaust brake valve device - Google Patents

Abstract

PURPOSE:To maintain the exhaust brake effect even during operation while the car is running, and make it possible to perform exhaust gas circulation even under the supercharged condition. CONSTITUTION:The valve casing 2 of an exhaust brake valve 1 is equipped with a circulation passage 3 and exhaust passage 4, and a brake valve element 5 is furnished to open and close the exhaust passage, wherein the circulation passage leads to a valve for circulation 8 which lies on the way of a circulating pipe 7, and the inlet side of the exhaust passage is in communication with the exhaust pipe 35 side of a turbo charger 9, and in the condition that the circulation passage is open while the circulating valve is in operation, the brake valve element is put in an appropriate position between full close and full open, and the exhaust pressure upstream of the brake valve element is made higher than the supercharge pressure of the turbo charger, and the circulation passage is also closed fully when the brake valve element is in full closed state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an exhaust brake valve device capable of providing an exhaust gas circulation valve in a diesel engine or the like.

[0002]

2. Description of the Related Art A conventional valve device shown in FIG.
An exhaust brake valve V having a warming function is provided downstream of the exhaust pipe P ₁ in which the turbocharger T is arranged,
The exhaust brake effect is obtained by closing the valve body B without providing an exhaust gas circulation valve. Also, FIG.
In the exhaust brake valve device shown in ( ₁₎ , a relief type warm air valve H is provided in the exhaust pipe P ₁ of the engine E via a turbocharger T, and exhaust gas circulation is performed in the middle of an exhaust gas circulation pipe P ₃ branched from the middle of the exhaust pipe P _1. The valve R is arranged so that the exhaust brake effect is obtained with the valve body B closed.

[0003]

However, in the valve device shown in FIG. 2, the pressure in the intake pipe P ₂ becomes higher than the pressure in the exhaust pipe P ₁ due to the supercharging pressure when the engine E has a high load, and the exhaust gas is exhausted. When the exhaust gas circulation valve is provided because the gas cannot be circulated, the exhaust valve causes the circulation valve to open when the exhaust brake is operated, and the pressure escapes. However, there was a problem that the exhaust brake effect was reduced.

In the device shown in FIG. 3, if the exhaust brake is operated while the vehicle is running, the exhaust gas circulation valve R will be opened, so that the exhaust brake cannot be set. E
When the load is high, the pressure in the exhaust pipe P ₁ is about 100 mmHg, while the pressure in the intake pipe P ₂ is about 500 to 600.
Since it is as high as mmHg, there is a problem that exhaust gas circulation cannot be performed. In view of such conventional drawbacks, the present invention provides an exhaust brake valve device capable of performing exhaust gas circulation even in a supercharged state without reducing the exhaust brake effect even when operated during traveling. The purpose is to

[0005]

In order to achieve the above object, the gist of the present invention is that a circulation passage communicating with a circulation valve in the middle of an exhaust gas circulation passage and an exhaust passage communicating with a turbocharger. And an exhaust brake valve having a brake valve body that opens and closes the exhaust passage, and when the circulation valve is in operation, the brake valve body is appropriately opened and closed while the circulation passage is open. The exhaust pressure on the upstream side of the brake valve body at a higher intermediate position than the supercharging pressure of the turbocharger,
In the exhaust brake valve device, the circulation passage is fully closed at the same time when the brake valve body fully closes the exhaust passage.

[0006]

In the exhaust brake valve device according to the present invention, when the circulation valve in the middle of the exhaust gas circulation path is operated, the circulation passage to the circulation valve is opened,
The brake valve body that opens and closes the exhaust passage communicating with the turbocharger is set to an appropriate intermediate position between fully closed and fully opened so that the exhaust pressure on the upstream side of the brake valve body is increased to be higher than the supercharging pressure of the turbocharger. By doing so, the exhaust valve can be re-circulated by operating the circulation valve even when the supercharging state is high, and the exhaust passage can be fully closed at the same time when the brake valve body is fully closed. The circulation valve does not operate during the operation of
Exhaust brake effect does not decrease.

[0007]

Embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the exhaust brake valve device according to this embodiment is provided with a circulation passage 3 and an exhaust passage 4 in a valve box 2 of an exhaust brake valve 1 (hereinafter referred to as “EXB valve”). A brake valve body 5 for opening and closing the exhaust passage 4 is provided, and the circulation passage 3 communicates with a circulation valve 8 in the middle of a circulation pipe 7 forming an exhaust gas circulation passage, and the inlet side of the exhaust passage 4 is an exhaust pipe of a turbocharger 9. 35, and when the circulation passage 3 is opened when the circulation valve 8 is operated, the brake valve body 5 is set to an appropriate intermediate position between the fully closed state and the fully opened state. The pressure is made higher than the supercharging pressure of the turbocharger 9, and when the brake valve body 5 is fully closed, the circulation passage 3 is also fully closed.

The valve box 2 of the EXB valve 1 has flanges 12 and 13 integrally formed at both ends of a tubular body 11, and has an inward step surface 14 along the inner circumference of the inlet side of the exhaust passage 4 near the flange 12. And the outwardly facing step surface 15 is used as the valve seat of the brake valve body 5, and both step surfaces 14, 1 in the axial direction are formed.
The distance between the two is substantially equal to the plate thickness of the brake valve body 5, and the circulation passage 3 is bent at a right angle from the inward step surface 14 to the outer peripheral surface of the flange 12 and is continuous. A muffler 17 is connected to the outlet side of the exhaust passage 4 through the.

The brake valve body 5 is provided with a valve shaft 18 between the side walls of the valve box 2 at a position deviated from the axis of the valve box 2, and is rotatably supported by the valve shaft 18 with a spacer 19 interposed. 1 and is substantially parallel to the axis including the axis of the valve box 2 when it is fully opened, as shown by the solid line in FIG. The plate surface abuts the corresponding step surfaces 14 and 15 and the circulation passage 3
Of the circulation passage 3 is closed, and at an appropriate intermediate position, the inlet of the circulation passage 3 is opened, as indicated by the inclined two-dot chain line.

In the circulation valve 8, a valve body 24 attached to a diaphragm 23 in the valve box 21 is biased by a compression coil spring 22 toward a valve seat 25, and an inlet 8b and an outlet 8c for circulating gas are respectively provided. Through the circulation passages 7 and 7 to the circulation passage 3 and the intake manifold 26 of the engine E, and through the exhaust pressure transducer 27 and the vacuum switching valve 28 to connect the vacuum pump 29 to the back chamber 8a through the pipe 30 and the back chamber 8a. Due to the relationship between the negative pressure when the internal pressure is reduced by the vacuum pump 29 and the urging force of the compression coil spring 22, the valve element 24 separates from the valve seat 25 and opens. As a result, the exhaust gas from the engine E is circulated and sent to the intake manifold 26, the amount of oxygen in the intake air is reduced, the combustion temperature is lowered, and the content of nitrogen oxides in the exhaust gas is reduced. The exhaust pressure transducer 2
Reference numeral 7 is for sensing the fluctuation of the exhaust pressure and adjusting the negative pressure to make the exhaust gas circulation amount constant.

The turbocharger 9 has an intake pipe 3 having one end connected to an air cleaner 31 and the other end connected to an intake manifold 26.
The impeller 33 arranged in the middle of 2 and the impeller 36 arranged in the middle of the exhaust pipe 35 having one end connected to the exhaust manifold 34 of the engine E and the other end connected to the inlet of the EXB valve 1 are connected by the common shaft 37. There is.

The exhaust brake valve device receives inputs regarding the engine E speed, radiator water temperature, supercharging pressure, accelerator opening, exhaust brake on / off (EXB valve 1 on / off), exhaust pressure and the like. The controller 39 receives the signal S, and the input signal S
Based on the signal output from the controller 39 based on
When the vacuum switching valve 28 is operated and the circulation valve 8 is opened to circulate the exhaust gas, the exhaust pressure at the point before the exhaust pipe 35 is connected to the EXB valve 1 is lower than the supercharging pressure of the turbocharger 9. The opening angle of the brake valve body 5 of the EXB valve 1 is controlled so that the brake valve body 5 of the EXB valve 1 is held at a slightly high position, and the brake valve body 5 of the EXB valve 1 is in a state of an appropriate intermediate position between fully closed and fully opened.

Next, the operation of the exhaust brake valve device according to the above embodiment of the present invention will be described. When the supercharging pressure is high in the high-speed operation of the engine E or when it is desired to increase the exhaust gas circulation amount, the circulation valve 8 is opened and the EX
The brake valve body 5 of the B valve 1 is in a state of being at an appropriate intermediate position between the fully closed state and the fully opened state. The exhaust passage 4 remains open, and in this state, the pressure in the portion before the exhaust pipe 35 is connected to the inlet side of the exhaust passage 4 becomes high, and the exhaust gas flows from the exhaust pipe 35 to the circulation passage 3 for circulation. It is sent to the engine E through the pipes 7, 7, the circulation valve 8 and the intake manifold 26 in the middle thereof. When the EXB valve 1 is fully closed, the inlet of the circulation passage 3 is also fully closed at the same time, and there is no possibility that the circulation valve 8 malfunctions due to the pressure in the exhaust pipe 35 and opens.

The results of experiments conducted on the valve device according to the above-mentioned embodiment under various conditions are shown below. When the engine has a low load and the supercharging pressure is atmospheric pressure, the radiator water temperature is less than 60 ° C, the brake valve body 5 of the EXB valve 1 is set to the intermediate position, the exhaust passage 4 is opened, and the circulation valve 8 is closed. , Exhaust pressure is +400 to +500
mmHg (here, “+” means a high differential pressure compared to atmospheric pressure. The same applies to the following), and the water temperature of the radiator is 60 to 80 ° C., and the EXB valve 1 and the circulation valve 8 are turned on. When both were opened, the exhaust pressure became +10 mmHg. The engine has a medium load and the supercharging pressure is from atmospheric pressure to +500.
When the water temperature is less than 60 ° C, when the EXB valve 1 is fully opened, the exhaust passage 4 is opened, and the circulation valve 8 is closed, the exhaust pressure becomes +10 to +100 mmHg, and the water temperature is 60 to 80 ° C.
When the EXB valve 1 was opened to half open and the circulation valve 8 was opened, the exhaust pressure became +10 to +600 mmHg.

The engine has a high load and the boost pressure is +5.
When the water temperature is less than 60 ° C, when the EXB valve 1 is fully opened, the exhaust passage 4 is opened, and the circulation valve 8 is closed, the exhaust pressure is +100 mmHg, and the water temperature is 60 to 80 ° C. When the EXB valve 1 is half open to full open, the exhaust passage 4 is open, and the circulation valve 8 is closed to open, the exhaust pressure is +600 to +100.
mmHg, exhaust gas pressure becomes +100 when accelerator is fully opened, EXB valve 1 is fully opened, and circulation valve 8 is closed.
It was mmHg. When the exhaust brake operates and the supercharging pressure is atmospheric pressure, the water temperature is less than 60 ° C, the EXB valve 1 is fully closed, the exhaust passage 4 is closed, and the circulation valve 8 is closed. / becomes cm ^2, the water temperature is similarly exhaust pressure be increased to 60-80 ° C. had 3-4 kg / cm ^2.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. For example, an EXB valve in which the valve shaft 18 passes through the axis of the valve box 2 may be used.
A sliding valve may be used instead of the butterfly type valve.

[0017]

The present invention is provided with a circulation passage communicating with a circulation valve in the middle of an exhaust gas circulation passage, an exhaust passage communicating with a turbocharger, and a brake valve body for opening and closing the exhaust passage. With the circulation passage opened when the valve is operated, the brake valve body is set to an appropriate intermediate position between fully closed and fully opened so that the pressure upstream of the brake valve body is higher than the supercharging pressure of the turbocharger. As a result, exhaust gas circulation can be reliably performed even in a supercharged state, and by fully closing the circulation passage when the brake valve body is fully closed, the exhaust brake effect can be achieved even when the exhaust brake is operated during traveling. It has an excellent effect that it does not decrease.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an exhaust brake valve device and its related equipment according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a conventional exhaust brake valve device and its related devices.

FIG. 3 is a circuit diagram showing another conventional exhaust brake valve device and its related devices.

[Explanation of symbols]

 1 Exhaust Brake Valve (EXB Valve) 2 Valve Box 3 Circulation Passage 4 Exhaust Passage 5 Brake Valve Body 7 Circulation Pipe (Constitutes Circulation Route) 8 Circulation Valve 9 Turbocharger 12 Flange 14, 15 Step Surface 18 Valve Shaft 32 Intake Pipe 35 exhaust pipe

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area F02M 25/07 P

Claims (1)

[Claims] 1. An exhaust brake valve having a circulation passage communicating with a circulation valve in the middle of an exhaust gas circulation passage, an exhaust passage communicating with a turbocharger, and a brake valve body opening and closing the exhaust passage, During operation of the circulation valve, the brake valve body is set to an appropriate intermediate position between the fully closed state and the fully opened state with the circulation passage open, and the exhaust pressure on the upstream side of the brake valve body is adjusted to the excess pressure of the turbocharger. The exhaust brake valve device is characterized in that the circulation passage is fully closed at the same time when the pressure is higher than the supply pressure, and the brake valve body fully closes the exhaust passage.