JPS6138329B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake and exhaust control device for an exhaust turbocharged engine.

In general, exhaust turbocharged engines have a marked increase in output at high loads and improved fuel consumption at high loads compared to non-supercharged engines, but on the other hand, fuel consumption decreases at low loads. rates tend to worsen. Furthermore, in exhaust turbocharged engines, the supercharger turbine often overspeeds at high loads;
When the load is high, the supply pressure and temperature of the supply air to the engine become excessive, resulting in a problem that the heat load on various parts of the engine becomes excessive.

Therefore, in order to take advantage of the advantages of exhaust turbocharging and eliminate its disadvantages, rather than keeping the engine and exhaust turbocharger connected over the entire engine load range, It can be said that it is preferable to operate in such a way that the engine and the exhaust turbocharger are shut off.

Conventionally, there is a method of installing a so-called waste gate as a method of this type, but the conventional waste gate method mainly only cuts off the exhaust gas supply to the supercharger turbine in high load ranges, and only when the engine is under full load. It was not possible to improve driving performance in this region. Taking these circumstances into consideration, the applicant has planned an exhaust turbocharged engine equipped with two bypass pipes that bypass the turbine and compressor of the exhaust turbocharger, and has already filed a utility model application for this. However, in the exhaust turbocharged engine of this patent application, a butterfly valve is provided in the bypass line on the turbine side, so there is a risk that this butterfly valve may malfunction due to the high heat of the exhaust. It wasn't practical.

On the other hand, apart from this, it is common for vehicle tower-mounted engines to have an exhaust brake valve installed in the exhaust manifold, etc. Conventionally, a butterfly valve has often been used as this exhaust brake valve, so it is similar to the above. However, there is a risk that the high heat of the exhaust gas may cause a failure, and therefore there was a need to improve the conventional exhaust brake valve.

The present invention has been made against the background of the above-mentioned circumstances, and an object of the present invention is to provide a system for an exhaust turbocharged engine having two bypass pipes that bypass the turbine and compressor of the exhaust turbocharger, respectively. The object of the present invention is to provide an intake/exhaust control device, and more specifically, to provide an intake/exhaust control device having a novel switching valve that is less likely to malfunction. Another object of the present invention is to provide a switching valve device with a simple structure that serves as both an exhaust switching valve and an exhaust brake valve. An object of the present invention is to provide an intake/exhaust control device equipped with the following.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a schematic structure of an intake and exhaust system of an exhaust turbocharged engine equipped with an intake and exhaust control device of the present invention. In the figure, 1 is an exhaust turbo supercharger, which has a turbine 2 and a compressor 3. An exhaust supply pipe 5 for supplying exhaust gas to the turbine 2 of the exhaust turbo supercharger 1 is connected to the exhaust pipe 4 connected to the exhaust manifold of the engine body, and also for supplying exhaust gas by bypassing the turbine 2. A turbine bypass pipe 6 is connected for direct discharge into the atmosphere.

An exhaust switching valve device 7 is provided midway between the exhaust supply pipe 5 and the turbine bypass pipe 6, crossing each of them. This exhaust switching valve device 7 includes a hollow and flat valve casing 8 (see also FIG. 2) that crosses the exhaust supply pipe 5 and the turbine bypass pipe 6, and inside the valve casing 8, the pipes 5 and 6 It has a plate-shaped sliding valve 9 that moves in a direction that crosses the area. A hole 10 communicating with the exhaust supply pipe 5 and a hole 11 communicating with the turbine bypass pipe 6 are bored in the side plate of the valve casing 8, as shown in FIG. As shown in FIG. 2, only a valve hole 12 communicating with the exhaust supply pipe 5 is bored. Total internal length of valve casing 8 L ₁
Although the total length _L2 of the slide valve 9 is almost equal, the hole 10 of the valve casing 8 and the valve hole 12 of the slide valve 9 are not provided in corresponding positions, and therefore, most of the slide valve 9 is When the entire valve casing 8 is inserted, the valve hole 12 of the slide valve 9 is positioned between the holes 10 and 11 as shown by the two-dot chain line in FIG. Both the supply pipe 5 and the turbine bypass pipe 6 will be cut off. On the other hand, when the tip 9' of the slide valve 9 is positioned at the position shown by the two-dot chain line in FIG.
and the valve hole 12 of the slide valve 9 match, and as a result, only the exhaust supply pipe 5 is opened. Also,
When the tip 9' of the slide valve 9 is further lowered than the position indicated by the two-dot chain line in FIG. 2 and the hole 11 in the valve casing is opened, the turbine bypass pipe 6 is opened through the inside of the valve casing 8. , conversely, the exhaust supply pipe 5 is cut off.

A flange 8a is provided at the open end of the valve casing 8, and a flange 9a as a stopper is also provided at the rear end of the sliding valve 9. However, even if a heat-resistant boot is installed between the flanges 8a and 9a, good.

A valve drive device 13 is connected to the slide valve 9 in order to drive the slide valve 9 in a direction across the exhaust supply pipe 5 and the turbine bypass pipe 6 . The valve drive device 13 may be of any type, but
In the illustrated embodiment, for example, a pneumatic cylinder 14 is used. An air pipe line 15 connected to both ends of the pneumatic cylinder 14 is provided with an electromagnetic intake/exhaust valve 16 whose opening degree can be switched in three stages. It is designed to be automatically operated by signals.

Turbine exhaust pipe 1 that guides the discharged exhaust gas of the turbine 2
8 merges with the turbine bypass pipe 6, so that the exhaust flows in both pipes 6 and 18 are discharged into the atmosphere.

On the compressor side of the exhaust turbo supercharger 1,
a fresh air introduction pipe 19 for guiding intake fresh air from an air cleaner (not shown) to the compressor 3;
It is connected to an air supply pipe 20 that introduces the discharge air of the compressor 3 into the engine body, and both pipes 1
9 and 20 are short-circuited by a compressor bypass pipe 21 that bypasses the compressor 3. A butterfly-type intake system switching valve 22 is provided at the connection between the compressor bypass pipe 21 and the fresh air introduction pipe 19, and also at the connection between the compressor bypass pipe 21 and the air supply pipe 20. A butterfly type intake system switching valve 23 is provided.
These intake system switching valves 22 and 23 are attached to rotating shafts 24 and 25 in the pipes, respectively, and as the rotating shafts 24 and 25 rotate, the valves move between the solid line position shown in the figure and the two-dot chain line position shown in the figure. is rotated. Each rotation shaft 24 and 25 is connected via links 26 and 27 to a valve drive device such as a solenoid or pneumatic cylinder 28 and 29, respectively, and is rotated by the valve drive device. Cylinders 28 and 29 are connected to respective air lines 30 and 31
It is operated by electromagnetic intake/exhaust valves 32 and 33 provided at. The electromagnetic intake and exhaust valves 32 and 33 are electrically connected to the main controller 17 and are operated synchronously by control signals from the main controller 17.

The main control device 17 controls the electromagnetic intake and exhaust valves 16, 32, and 33 according to the operating state of the engine body and the operating state of the vehicle, and is constituted by a non-contact sequence control device, a small computer, or the like. The main control device 17 receives detection signals S generated from various detectors (not shown) (for example, a detection signal of the load of the engine body, a detection signal of the vehicle speed, a detection signal of the cooling water temperature of the engine body, and an atmospheric pressure detection signal). detection signals, outside temperature detection signals, etc.) are being introduced.

Next, the operation of each part will be explained when the exhaust turbocharged engine having the intake/exhaust system and intake/exhaust control device as described above is used as a vehicle-mounted engine.

When the engine is started, the sliding valve 9 of the exhaust switching valve device 7 is positioned at the position A indicated by the dashed dot line in FIG.
Therefore, in the exhaust system, only the turbine bypass pipe 6 is opened through the hole 11 of the valve casing 8, so that the engine is set to a non-supercharging operating state. on the other hand,
In synchronization with this, the electromagnetic intake and exhaust valves 32 and 33 are operated, and the intake system switching valves 22 and 23 are positioned as indicated by the two-dot chain line in FIG. 1, and as a result, the compressor bypass pipe 21 is set to the open state. , the intake system is also set to non-supercharging operation.

This non-supercharging operating state is maintained when the engine is idling and when the load and engine speed are extremely small, but if the load reaches a predetermined low load range, the main control The electromagnetic intake/exhaust valves 16, 32, and 33 are switched by the control signal from the device 17, and the slide valve 9 is positioned as shown in FIG. They are respectively positioned at the positions indicated by solid lines. As a result, the exhaust supply pipe 5 is opened through the valve hole 12 in the exhaust system, and the fresh air introduction pipe 19 and the air supply pipe 20 are opened in the intake system. Therefore, the exhaust turbo supercharger 1 enters the operating state, and the engine is operated with supercharging.

When the vehicle speed is high and the load is quite small, the electromagnetic intake/exhaust valves 16, 32, and 33 are switched by a control signal from the main controller 17, and the slide valve 9 is moved again to the position shown by the dashed-dotted line in FIG. At the same time, the intake system switching valves 22 and 23 are moved to the positions indicated by the two-dot chain line in FIG. 1, so that the engine is maintained in non-supercharging operation.

When the exhaust brake is operated while either supercharging operation or non-supercharging operation is being continued, the slide valve 9 is completely inserted into the valve casing 8 by the valve drive device 13, and the valve hole 12 is inserted into the valve casing 8. It is positioned at the position indicated by the two-dot chain line in Figure 2. As a result, the exhaust supply pipe 5 and the turbine bypass pipe 6 are closed simultaneously, and the exhaust gas is confined within the exhaust manifold 4. At the same time, in the intake system, the intake system switching valve 23 is operated to the solid line position in FIG.
By holding the cylinder at the position indicated by the two-dot chain line in FIG. 1, backflow from the cylinder is prevented. Therefore, a large braking force is generated on the crankshaft via the piston, and an exhaust brake operation is performed.

In the intake/exhaust control device of the present invention as described above, a sliding valve is used in place of the conventional butterfly type switching valve as the switching valve provided in the exhaust system. A switching valve device is constructed that eliminates the risk of failure due to defects and is superior in both reliability and durability. On the other hand, unlike conventional butterfly valves, this switching valve device does not have a valve body in the gas flow path, so a secondary effect of reducing flow path loss is also obtained.
In addition, since the switching valve device has the function of an exhaust brake valve, it can also be used when an exhaust turbocharged engine with a bypass pipe in the intake and exhaust system is used for a vehicle as described above. It is no longer necessary to separately install an exhaust brake valve, which prevents an increase in engine manufacturing costs and reduces the number of maintenance steps.

In the embodiments shown in FIGS. 1 and 2, the switching valve device 7 is configured as a linear reciprocating type sliding valve, but it can also be configured as a rotary reciprocating type or oscillating type sliding valve. You may. Furthermore, not only the switching valve for the exhaust system but also the switching valve for the intake system may be a sliding valve.

In another embodiment of the present invention shown in FIG. 3, the intake system is provided with a first sliding type intake system switching valve device 34 of a linear reciprocating type, and a second sliding type of rotary reciprocating type. An intake system switching valve device 35 is provided. (Description of parts indicated by the same reference numerals as shown in FIG. 1 will be omitted.) The first intake system switching valve device 34 has the same structure as that of the intake system as shown in FIG.
It is installed across the fresh air introduction pipe 19 and the air supply pipe 20. This first intake system switching valve device 34 has a flat valve casing 36 that crosses the fresh air introduction pipe 19 and the air supply pipe 20, and also connects the fresh air introduction pipe 19 and the air supply pipe 20 within the valve casing 36. It has a plate-shaped sliding valve 37 that moves across the traverse. The valve casing 36 is provided with two holes that correspond to the fresh air introduction pipe 19 and the air supply pipe 20, respectively;
The slide valve 37 is also provided with two valve holes 38, 39 that match these holes. The sliding valve 37 is connected to a valve driving device 40 such as an air cylinder, and supplies fresh air to the compressor 3 and controls the compressor 3.
The compressor 3 is moved alternately between a first position, which blocks air discharged from the compressor 3, and a second position, which allows fresh air to be supplied to and discharged from the compressor 3.

On the other hand, a swing-type second intake system switching valve device 35 is provided in the compressor bypass pipe 21 so as to cross the bypass pipe 21 . This intake system switching valve device 35 has a flat fan-shaped valve casing 41 (see FIG. 4) that crosses the bypass pipe 21, and a plate-shaped valve 42 that swings within the valve casing 41. There is. The valve casing 41 is provided with a hole 43 communicating with the compressor bypass pipe 21 and a shaft hole 44, and a guide rail 45 is provided protruding from the inner wall surface. on the other hand,
The valve 42 is provided with a hole 46 that matches the hole 43 of the valve casing 41 and a guide rail 47.
8 is fixed. The rotating shaft 48 is inserted into the shaft hole 44 of the valve casing 41, protrudes to the outside, and is connected to a rotary valve drive device 49. This valve driving device 49 is a device that is reciprocated by compressed air and is connected to the pneumatic piping 51 of the valve driving device 40 via a pneumatic piping 50.

Pneumatic pipes 51 and 52 of the valve drive device 40 are connected to the valve drive device 13 of the exhaust switching valve device 7 and are configured to operate in synchronization with the valve drive device 13 of the exhaust system. On the other hand, the valve driving device 13 of the exhaust switching valve device is provided with the pneumatic piping 15, and the pneumatic piping 15 is provided with an intake/exhaust switching valve 16 that is switched by a control signal from the main controller 17. . Further, a pneumatic source Q is connected to the pneumatic piping 15 via a suction/exhaust switching valve 16 .

In the embodiment shown in FIG. 3, when the intake/exhaust switching valve 16 is switched by a control signal from the main controller 17,
The exhaust switching valve device 7 is configured such that (a) only the exhaust supply pipe 5 is opened;
(b) Only the turbine bypass pipe 6 is opened; (c) Both the exhaust supply pipe 5 and the turbine bypass pipe 6 are closed. A first position that simultaneously opens the air supply pipe 20 and the fresh air introduction pipe 19.
and a second position that simultaneously closes the intake pipe 20, and the other intake system switching valve device 3
5 is positioned at a first position where the compressor bypass pipe 21 is in a closed state and a second position where the compressor bypass pipe 21 is in an open state. As a result, when exhaust gas is supplied from the exhaust supply pipe 5 to the turbine 2, the fresh air introduction pipe 19 and the air supply pipe 20
are opened at the same time, and the compressor bypass pipe 21 and the turbine bypass pipe 6 are simultaneously closed to perform supercharging operation. During non-supercharging operation, the turbine bypass pipe 6 and the compressor bypass pipe 2 are closed simultaneously.
1 is open and the other tubes are closed.

The embodiment shown in FIG. 3 is characterized in that a sliding type switching valve device is provided not only in the exhaust system but also in the intake system, so that flow path loss can be reduced more than in the conventional butterfly valve.

As explained above, the intake and exhaust control device of the present invention makes use of the advantages of the exhaust turbocharged engine, eliminates the disadvantages, and creates a practical and reliable exhaust turbocharged engine without the risk of failure. realizable. Furthermore, in the intake/exhaust control device of the present invention, the switching valve device provided in the exhaust system has the function of an exhaust brake valve, so there is no need to provide a separate exhaust brake valve. Since it is configured as a sliding valve, failures due to thermal deformation can be prevented and manufacturing costs can be prevented from increasing.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a first embodiment of the present invention, FIG. 2 is a sectional view taken along the - arrow in FIG. 1, FIG. 3 is a schematic diagram showing another embodiment of the present invention, and FIG. FIG. 4 is a front view showing the valve casing and valve of the sliding valve type switching valve used in the embodiment of FIG. 3; 1: Exhaust turbo supercharger, 2: Turbine, 3: Compressor, 4: Exhaust pipe, 5: Exhaust supply pipe,
6: Turbine bypass pipe, 19: Fresh air introduction pipe, 2
0: Air supply pipe, 21: Compressor bypass pipe,
7: Exhaust switching valve device, 22, 23: Intake system switching valve, 34, 35: Intake system switching valve device.

Claims (1)

[Claims] 1. An exhaust supply pipe for supplying exhaust gas to the turbine of the exhaust turbo supercharger, a turbine bypass pipe for bypassing the turbine and releasing the exhaust gas directly into the atmosphere, and a compressor for the exhaust turbo supercharger. a fresh air introduction pipe for introducing fresh air into the compressor, an air supply pipe for guiding the exhaled air from the compressor to the engine main body, and a compressor for bypassing the compressor by short-circuiting the fresh air introduction pipe and the air supply pipe. An intake/exhaust control device for an exhaust turbocharged engine, the intake/exhaust control device being installed across both the exhaust supply pipe and the turbine bypass pipe at the same time. a single sliding valve type exhaust switching valve device; an intake system switching valve for opening and closing each of the fresh air introduction pipe, the air supply pipe, and the compressor bypass pipe; the exhaust switching valve device; 1. An intake and exhaust control device for an exhaust turbocharged engine, comprising: a main control device that synchronously controls an intake system switching valve according to a predetermined sequence.