JPS63212712A - Exhaust manifold cooling device - Google Patents

Abstract

PURPOSE:To control an exhaust manifold to the optimum temperature and to improve durability by forming a water jacket in the periphery of the exhaust manifold, providing water injection means, and controlling the water injection quantity according to the exhaust temperature. CONSTITUTION:A water jacket 17 is formed in the periphery of an exhaust manifold 6, and a water injection nozzle 20 is provided thereon. Exhaust temperature sensors 33, 34 are provided on an exhaust manifold collecting portion 30 and a catalytic converter 32, and the injection of the water injection nozzle 20 is controlled according to the exhaust temperature by a control unit 21. Thus the temperature of the exhaust manifold is controlled to the optimum so as to improve the durability of the exhaust manifold and improve exhaust emission.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an exhaust manifold cooling device that efficiently cools an exhaust manifold using water injection, and in particular, the present invention relates to an exhaust manifold cooling device that efficiently cools an exhaust manifold using water injection. This invention relates to a device that can optimize the degree.

[Conventional technology] In order to improve the durability of the exhaust manifold itself and the heat resistance of the supercharger, or to reduce the exhaust temperature and reduce the fuel OT (o
ver Temperature) reduction in volume increase, WOT
(Wide 0 Pen Throttle) It is known that cooling the exhaust manifold is effective in reducing fuel consumption, improving performance such as Ia engine output torque, and suppressing knocking.

As a forced cooling method for exhaust manifold, Utility Model Application No. 61-5
A method using air cooling is also considered, similar to the exhaust pipe cooling described in Japanese Patent No. 7118 and Japanese Utility Model Application No. 61-78213@, but since the cooling capacity is limited in the case of air cooling, great effects cannot be expected.

Various methods using water cooling have been proposed as highly efficient cooling methods.

For example, Utility Model Application No. 61-21814@publication, Utility Model Application No. 61-21814@publication
Publication No. 134513@ discloses a structure in which a water jacket is provided around the outer periphery of the exhaust manifold, and cooling water is not allowed to flow through the A-water jacket. In addition, although it is not intended for cooling the exhaust manifold, a water shower is applied to the outer wall of the cylinder (C, J). ).In addition, a structure is known in which a flow of cooling air containing fine water droplets is applied to the entire engine with cooling fins (Japanese Patent Laid-Open Publication No. 55-60618).

However, in the structures shown in Japanese Utility Model Application Publication No. 61-21814 and Japanese Utility Model Application Publication No. 61-134513, the structure is such that the A-ta jacket formed around the outer circumference of the exhaust manifold is filled with cooling water. There is a problem in that the heat capacity of the exhaust manifold increases due to the presence of water, which worsens engine warm-up performance. In addition, in the case of the water-cooled structure as described above, it is necessary to release the amount of heat absorbed by the exhaust manifold to the atmosphere by the engine cooling water radiator, and there is also the problem that the radiator needs to be larger.

Furthermore, although the structure shown in Japanese Utility Model Application Publication No. 56-138113 is not intended for exhaust manifolds, even if such an IM structure were applied to the water jacket around the exhaust manifold, it would simply be a water shower. Since the water shower is not uniformly distributed within the water jacket 1, there is a problem that the exhaust manifold is not cooled uniformly.The high temperature exhaust manifold is cooled unevenly. If this happens, it may even encourage thermal distortion of the exhaust manifold.

In order to solve the above-mentioned problems, the applicant first introduced water in the form of a spray from a water injection means into the A-jacket formed around the outer periphery of the exhaust manifold. By using the latent heat of vaporization of A device has been proposed that cools the air well.In particular, a part of the supercharged air is introduced into a four-wheel jacket, and water spray is introduced along with the flow of the supercharged air. 1- can be uniformly dispersed within the interior of the room, making it possible to achieve even more uniform cooling.

[Problems to be Solved by the Invention] The present invention relates to an improvement of the exhaust manifold cooling device proposed by the present applicant in the above light, and the degree of cooling of the exhaust manifold is determined based on the actual state of the engine at that time. The purpose is to make it possible to optimize according to the

[Means for solving the problem] The υ1 atmosphere manifold cooling device of the present invention that meets this objective has the following features:
In an engine equipped with an exhaust manifold cooling device having a water jacket formed around the exhaust manifold and a water injection means capable of injecting atomized water into the water jacket, the exhaust system of the engine, e.g. An exhaust temperature sensor is installed in the exhaust manifold and immediately after the catalyst installed in the exhaust system, and the amount of water injected from the water injection means is controlled via a control device based on the signal from the exhaust temperature sensor. #J Consists of something that is covered.

Here, the water injection means is, for example, a water injection nozzle, or a part of the supercharged air is introduced into an A-ta jacket, a venturi is provided in the supercharged air introduction passage, and water is supplied from the water tank to the venturi part. The water supply channel is equipped with a solenoid valve or a flow rate control valve.

When the water injection means is a water injection nozzle, the water injection amount DA is controlled by controlling continuous injection, intermittent injection, or stop.

[Function] In such an exhaust manifold cooling device, atomized water is introduced into the water jacket I around the exhaust manifold, and is uniformly dispersed within the water jacket 1 to mainly form a water spray. The high-temperature exhaust manifold is efficiently cooled by the latent heat of vaporization when the gas is vaporized by the heat of the exhaust manifold, but the actual engine condition J3 and The catalyst activation state is accurately detected, and the water injection amount is controlled to be the optimum amount based on it. Therefore, the exhaust manifold is cooled to maintain an optimum temperature depending on the actual engine conditions.

As a result, the temperature of the exhaust manifold is optimized, and by optimizing the exhaust gas temperature, the activity of the catalyst is optimized to improve exhaust emissions and fuel efficiency, and the durability and reliability of the exhaust manifold is improved by preventing overheating and rapid cooling. Furthermore, warm-up performance and the like can be efficiently achieved.

[Embodiments] Preferred embodiments of the present invention will be described below with reference to the drawings.

First Embodiment FIG. 1 shows a cooling device for an exhaust manifold according to a first embodiment of the present invention. In the figure, 1 is the engine, 2
3 is a cylinder block, 3 is a cylinder head, 4 is an intake manifold connected to an intake port 5, and 6 is an exhaust manifold connected from an exhaust boat 7, respectively. A supercharger 8 is attached to the exhaust manifold 6, and exhaust gas is introduced into a turbine 9 of the supercharger 8, and an air flow meter 10. Air taken in through the suction duct 11 is compressed by the compressor g12. The compressed air is
The supercharged air is sent to the intercooler 14 via the intake duct 13, and from the intercooler 14 to the intake system via the intake duct 15. 16 indicates a throttle valve.

Up to this point, the structure is the same as that of a normal supercharged engine, but the following mechanism is provided in the present invention.

An A-tater jacket 11 is provided around the outer periphery of the exhaust manifold 6, covering almost the entire area thereof.

The Δ-taper jacket 17 is formed by making the exhaust manifold 6 into a two-Φ pipe structure. A supercharged air introduction passage 18 is provided between the water jacket 17 and the intake duct 15 so that the two can communicate with each other, so that a part of the supercharged air can be introduced through the supercharged air introduction passage 18. It has become. A check valve 19 is installed at the connection portion of the supercharged air introduction passage 18 to the intake duct 15 to prevent backflow of air from the supercharged air introduction passage 18 side to the intake duct 15 side.

1) Spray water in the form of a spray from one side of the supercharged air introduction passage 18 (in the vicinity of the cellar 1-1 population, from the direction G into the cellar jacket 1-11). A nozzle 20 is provided. This water injection nozzle 20 is connected to EC1J21 as a control device and is operated based on a signal from EC1J21. This water injection nozzle 20 basically has the same configuration and function as a fuel injection nozzle under EFI control, and injects water toward the water jacket 17 in a controlled manner.

A drain pipe 22 is connected to the lower part of the water jackets 1 to 17 as a discharge passage for discharging water together with the supercharged air from the water jacket 17.

The drain pipe 22 is provided with cooling fins 23 to condense water spray from the water jacket 17 by air cooling. The lower end of the drain pipe 22 is connected to a drain tank 24, air and water from the drain pipe 22 are separated in the upper space of the drain tank 24, and water is stored in the lower part. The drain tank 24 is connected to a pump 25, and the pump 25 circulates the water in the drain tank 24 through a water return pipe 26 to the water injection nozzle 20 again. Further, 27 indicates a baffle plate, and 28 indicates a steam/water separation filter, so that the drained supercharged air is returned to the upstream side of the compressor 1 no. 12 of the supercharger 8 via a return pipe 29. It has become. .

The exhaust manifolds 6 are assembled at an exhaust manifold collection section 30 and connected to an exhaust pipe 31. A catalytic converter 32 is provided in the middle of the exhaust pipe 31 or at a position immediately after the exhaust manifold gathering portion 30, and a catalyst for purifying exhaust gas (the path shown in the figure) is accommodated within the catalytic converter 32.

The exhaust manifold collecting part 30 is provided with an exhaust temperature sensor 33 (e.g., a reamister) that detects the temperature of the exhaust manifold collecting part 30 itself or the exhaust gas passing through the inside. Sen ° Su・34 (
For example, a reamister) is provided. Detection signals from these exhaust temperature sensors 4J33.34 are sent to the ECU 21. In the ECU 21, as shown in FIG. 2, the signals from the exhaust temperature sensor 4J33.
The temperature is compared with the preset temperature in step 5.36. In the comparator 35, the set temperature for comparison is, for example, 85.
0'C, and the comparator 36 outputs, for example, 800C.
It is assumed to be °C. The signals from comparators 35 and 36 are
When the signal is input to the OR circuit 37 and one or both of the exhaust temperature sensors 33 and 34 exceeds the above set value, an exhaust temperature increase signal is issued from the OR circuit 37h1 to the CPU 38. There is. From the CP tJ 38, through a suitable signal processing circuit, the water injection nozzle 20
An operation control signal is sent to. Furthermore, in this embodiment, EC
A fuel cut signal 39 is also input to the LI 21, and based on the input signal 39, the water injection nozzle 20
operation can be controlled.

In the embodiment device constructed as described above, the water injected from the water injection nozzle 20 rides on the flow of supercharged air introduced from the supercharged air introduction passage 18, becomes atomized, and becomes a water spray. The latent heat of vaporization efficiently removes the heat from the exhaust manifold 6, is cooled and condensed in the drain pipe 22, and is stored in the drain tank 24.The collected water is again injected into the water jet. The supercharged air sent to the injection nozzle 20 and subjected to steam and water separation is returned to the upstream side of the compressor 12.

In such a system, the amount of water injected from the water injection nozzle 20 is controlled as follows depending on the state of the engine.

As shown in FIG. 3, the control performed by the ECU 21 is first determined in step 101 based on the signals from the exhaust gas temperature sensors 33, 34 as to whether or not the exhaust gas temperature has risen above a set value. If both the exhaust temperature and the exhaust temperature sensor 1J33.34 are below the set value, warm-up has not been done sufficiently and the catalyst has not reached a sufficient activation temperature. Then, the driving of the water injection nozzle 20 is stopped. At this time, the jet pulse of the water jet nozzle 20 is stopped as shown in FIG. 4.

When either of the exhaust gas temperatures exceeds the set value, or both exceed the set value, the process proceeds to step 102, where it is determined whether or not the fuel is being cut.

In step 102, it is determined whether the fuel level is 1 or 1. If the fuel is being cut, the process proceeds to B, where the fuel is stopped after several intermittent injections as shown in FIG. Prevents the exhaust temperature from dropping during operation. Next, if the fuel is not being cut, the process proceeds to C, and as shown in FIG. 6, the fuel is intermittently injected several times and then continuously injected. As a result, compared to rapid continuous injection,
Rapid cooling due to continuous injection (causing cracks in the exhaust manifold,
Distortion (thermal shock) is prevented. Note that the ON and OFF time settings for intermittent injection are determined based on suitability.

In this way, in the device of the present invention, the amount of water injected from the water injection nozzle 20 is controlled based on the actually detected exhaust gas temperature, so that the amount of water injected from the water injection nozzle 20 is controlled accurately as desired in accordance with the actual engine condition at that time. Cooling of the exhaust manifold 6 is carried out.

Second Embodiment Next, FIG. 7 shows a second embodiment of the present invention. In this embodiment, a water injection nozzle is not provided, and a venturi 41 is provided in the middle of the supercharged air introduction passage 18.Then, water from the water tank 42 is inserted into the smallest diameter part of the venturi. A water supply pipe 43 is opened so that water can be injected.A solenoid valve (shutoff valve) 44 is installed in the water supply pipe 43, and water is supplied from the water tank 42 to the old venturi part via the water supply pipe 43. The electromagnetic valve 44 may be a flow rate adjustment valve that can shut off the water and also adjust the flow rate of the water. This is a balance pipe that balances the pressure inside the water tank 42.In addition, in this embodiment, a heat exchange pipe 48 that guides the refrigerant from the coolant compressor 4747 is wrapped around the drain pipe 46, It is configured to be able to condense water vapor.

Even in the embodiment device having such a configuration, the electromagnetic valve 44 is controlled according to the actual conditions of the engine by the ECLJ 21 based on the detection signals from each exhaust temperature sensor. Basically, it is possible to accurately control the water jet DAm in the same way. As mentioned above, it is also possible to use a flow control valve instead of the electromagnetic valve 44, so that the water injection is performed continuously instead of in a pulsed manner as in the first embodiment, and the flow rate is controlled. . Other configurations and functions are similar to those in the first embodiment, so the same reference numerals as in FIG. 1 are used for parts in FIG. 7 that correspond to those in FIG. 1.
Therefore, the explanation will be omitted.

[Effect 1 of R-light] As explained above, the exhaust manifold cooling device of the present invention has a cooling effect when water is injected into the taja wood formed on the outer periphery of the exhaust manifold. )
Jffl can be accurately controlled to the optimum amount by understanding the actual engine condition based on the detection signal from the exhaust temperature sensor, so the exhaust manifold salt can be adjusted to the optimum value according to the actual engine condition. It becomes possible to control
It is possible to further improve the durability and reliability of the υ1 air manifold by improving fuel efficiency, improving exhaust emissions, preventing overheating of the exhaust manifold, and preventing rapid cooling.

It is also possible to prevent deterioration of emissions due to a temperature drop in the exhaust manifold during warm-up, and also to prevent a temperature drop in the exhaust manifold during fuel exhaust.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an exhaust manifold cooling device according to a first embodiment of the present invention, FIG. 2 is a block diagram of water injection control that is applied to the device shown in FIG. 1, and FIG. 3 is a diagram similar to that shown in FIG. 1. The control flow diagram in ECLI of the device shown in FIG. 4 to FIG.
FIG. 7 is an overall configuration diagram of an exhaust manifold cooling device according to a second embodiment of the present invention. 1... Engine 2... Cylinder block 3...
・・・・・・・・・Cylinder head 4・・・・・・・・・
...Intake manifold 6...Exhaust manifold 8...Supercharger 9... Turbine 10... Air flow meter 11.
・・・・・・・・・・Suction duct 12・・・・・・・
・・・・・・Compressor 14・・・・・・・・・・・・
Intercooler 15...Intake duct 1
-17・・・・・・・・・・・・A-ta jacket 1
8......Supercharged air introduction passage 19...
......Reverse 1 valve 20...Water injection nozzle 21...
......ECtJ22.46...Drain pipe 23...Cooling fin 24...
・・・・・・・・・Drain tank 25・・・・・・・・・
・・・Pump 2G・・・・・・・・・Water return pipe 27・
......Baffle plate 28...
・・・・・・・・・Filter 29・・・・・・・・・・・・
・Return pipe 30・・・・・・・・・Exhaust manifold gathering part 31・・・・・・・・・Exhaust pipe 32・・・・・・・・・Catalytic converter 33.3
4...Exhaust temperature sensor 1 35.36...
Comparator 37......OR circuit 38...
......CPU 39...Fuel cut signal 4
1・・・・・・・・・・・・Venturi 42・・・・・・
・・・・・・Water tank 43・・・・・・・・・・・・
Water supply pipe 44... Solenoid valve 45... Balance pipe 47...
・・・・・・・・・Couran Koburetsuri 48・・・・・・
...Heat exchange pipe patent applicant
Toyota Autotun Co., Ltd. Figure 3

Claims (1)

[Claims] (1) In an engine equipped with an exhaust manifold cooling device having a water jacket formed around the exhaust manifold and a water injection means capable of injecting water in the form of atomized water into the water jacket, the exhaust of the engine An exhaust manifold cooling device characterized in that an exhaust gas temperature sensor is provided in the system, and the water injection means is connected to a control device that controls the amount of water injected by the water injection means based on a signal from the exhaust temperature sensor.