JPH0540272Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an exhaust turbocharging system for an engine, and in particular a primary exhaust turbocharging device that operates constantly and a secondary exhaust turbocharging device that stops in a specific operating range. Concerning measures to improve supercharging efficiency of equipped equipment.

(Prior art) Conventionally, as an engine exhaust turbo supercharging device,
For example, as disclosed in Japanese Utility Model Application No. 60-178329, the turbines of the primary and secondary exhaust turbo superchargers are connected in parallel to the exhaust manifold in the exhaust passage, and the compressor of the two exhaust turbo superchargers is connected in parallel to the exhaust manifold. is connected to the intake passage of the engine, and an exhaust cut valve is provided in the exhaust passage on the upstream side of the turbine of the secondary exhaust turbo supercharger. At times, the exhaust cut valve is closed to intensively supply exhaust gas from the exhaust passage to the turbine of the primary exhaust turbocharger to ensure high boost pressure, but when the engine is not in a specific operating range, In other words, in this case, when the exhaust gas flow rate is higher than the above set value, the exhaust cut valve is opened and the exhaust gas from the exhaust passage is supplied to the turbines of the two exhaust turbo superchargers to maintain the intake flow rate and maintain proper overflow. Some devices are known that provide supply pressure. In addition, in order to simplify the structure of the exhaust pipe, the primary exhaust turbo supercharger and the secondary exhaust turbo supercharger are arranged with their turbine discharge ports facing each other. An exhaust gas collecting section is provided between the two to collect exhaust gas from each turbine discharge port, and the exhaust pipes are unified downstream from the exhaust gas collecting section.

(Problem to be solved by the invention) However, in the above conventional system, when the engine is not in a specific operating range, the primary and secondary exhaust turbo superchargers operate, so the exhaust from the discharge ports of each turbine is A problem arises in that the exhaust gases interfere with each other at the exhaust collecting portion, increasing exhaust resistance.

The present invention was devised in view of this point, and its purpose is to match the spiral direction of the scrolls of each turbine so that when these turbines are arranged facing each other, the exhaust gas from the discharge port of each turbine is reduced. The purpose is to ensure that the swirling directions of the flows are the same downstream of the exhaust gas collecting section and to prevent interference of exhaust gas at the exhaust gas collecting section.

However, in that case, one exhaust turbo supercharger is connected to the exhaust flow FM from the exhaust manifold and the exhaust flow inside the turbine scroll, as shown in Figure 3.
If the exhaust manifold is connected to the FT so that the axial direction of the exhaust turbo supercharger and the FT are the same, the other exhaust turbo supercharger will be connected to the exhaust manifold as shown in Fig. As such, it is necessary to connect the exhaust manifold so that the exhaust flow FM from the exhaust manifold and the exhaust flow FT in the turbine scroll are in opposite directions around the axis of the exhaust turbo supercharger. For this reason, in an exhaust turbocharger where the exhaust flow FM from the exhaust manifold and the exhaust flow FT in the turbine scroll are in opposite directions, the exhaust flow will not be smooth.
It becomes less efficient.

Therefore, the present invention targets the primary exhaust turbo supercharger, which is in constant operation and is frequently used, by aligning the direction of the exhaust flow from the exhaust manifold with the exhaust flow within the turbine scroll. It also aims to effectively increase efficiency.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, primary and secondary exhaust turbo superchargers whose scrolls have the same spiral direction are arranged facing each other, and the exhaust flow from the exhaust manifold and the inside of the turbine scroll are The exhaust flow and the direction around the axis of the exhaust turbocharger are the same in the primary exhaust turbocharger,
The secondary exhaust turbo supercharger is in the opposite direction.

Specifically, the solution taken by the present invention includes primary and secondary exhaust turbo superchargers that supercharge intake air using the energy of exhaust gas from the exhaust manifold, and the primary exhaust turbo supercharger is constantly operated. The present invention is based on an engine exhaust turbocharger configured to stop a secondary exhaust turbocharger in a specific operating range. and,
On the other hand, the spiral direction of the turbine scroll toward the exhaust discharge direction is made to match between the primary exhaust turbo supercharger and the secondary exhaust turbo supercharger, and the primary exhaust turbo supercharger and the secondary exhaust turbo supercharger are A charger is arranged with the discharge ports of the turbines facing each other, and an exhaust collection part is provided between the two exhaust turbo superchargers to collect the exhaust gas from each turbine discharge port, and an exhaust flow from the exhaust manifold is provided. and the exhaust flow in the turbine scroll around the axis of the exhaust turbocharger are in the same direction for the primary exhaust turbocharger and in opposite directions for the secondary exhaust turbocharger. The structure is such that the engine is connected to the exhaust manifold.

(Function) With the above configuration, in the present invention, the spiral direction of the turbine scroll toward the exhaust discharge direction is the same in the primary exhaust turbo supercharger and the secondary exhaust turbo supercharger, so that the two exhaust turbo superchargers The swirling directions of the exhaust flows from each turbine discharge port of the supercharger are aligned downstream of the exhaust gas collecting section, preventing interference of exhaust gas at the exhaust collecting section, and reducing exhaust resistance.

In addition, the exhaust flow from the exhaust manifold and the exhaust flow in the turbine scroll are oriented in the same direction around the axis of the exhaust turbocharger in the primary exhaust turbocharger, which is always active, and in the secondary direction, which stops in a specific operating range. In the case of an exhaust turbo supercharger, the direction is reversed, so the exhaust flow of the frequently used primary exhaust turbo supercharger becomes smoother, increasing the efficiency of the turbocharger, and effectively increasing the efficiency of the entire supercharging system. It will be done.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

1 and 2 show a three-rotor type rotary piston engine equipped with an exhaust turbo supercharger according to an embodiment of the present invention. In these figures, 1 is a housing consisting of an intermediate housing, a rotor housing, and a side housing, and within the housing 1, three polygonal rotors 2, 2, 2 are arranged. The rotor 2 rotates planetarily to cause the three working chambers formed within the housing 1 to perform intake, compression, explosion, expansion, and exhaust strokes in sequence.

The housing 1 is provided with a primary port 3 and a secondary port 4 that supply fresh air to the working chamber during the intake stroke. The housing 1 is also provided with an exhaust port 5 for discharging exhaust from the working chamber during the exhaust stroke.

An intake passage 10 is connected to the primary port 3 and secondary port 4 corresponding to each of the rotors 2 at their branched ends, and the intake passage 10 is opened to the atmosphere via an air cleaner 13. The intake passage 10 has two intake passages 11 and 12 on the way.
It is divided into. Further, downstream of the merging portion of the intake passage 10, in order from the upstream side, there is an intercooler 14 for cooling the intake air, a throttle valve 15 for adjusting the intake air flow rate, and a throttle valve 15 for relaxing the pulsation of the intake air. A surge tank 16 is provided. Further, in the intake passage 10, injectors 17 and 1 are provided facing the primary port 3 and the secondary port 4 for injecting and supplying fuel.
8 are provided respectively.

Further, an exhaust passage 20 is connected to the exhaust ports 5, 5, 5. That is, the exhaust passage 2
One end of 0 is connected to two exhaust passages 2, first and second.
The exhaust passage 21 on one side is connected to the two exhaust ports 5, 5 related to the rotors 2, 2 in the center, and the exhaust passage 22 on the other side is connected to the exhaust ports 5, 5 on the rotors 2, 2 in the center. It is connected to an exhaust port 5 related to the rotor 2.

This engine is provided with a large primary exhaust turbo supercharger 31 and a small secondary exhaust turbo supercharger 32. That is, the turbine 31a of the primary exhaust turbo supercharger 31 is located in the first exhaust passage 21, and the turbine 31a of the primary exhaust turbo supercharger 31 is located in the second exhaust passage 22.
are each provided with a turbine 32a of a secondary exhaust turbo supercharger 32, and a first
A primary exhaust turbo supercharger 3 is installed in the intake passage 11.
A compressor 31b of the secondary exhaust turbocharger 32 is provided in the second intake passage 12, and a compressor 32b of the secondary exhaust turbo supercharger 32 is provided in the second intake passage 12, respectively, so that the intake air is supercharged by the energy of the exhaust gas.
Further, the first and second exhaust passages 21 and 22 are connected via a communication passage 33 on the upstream side of each exhaust turbo supercharger 31 and 32.

Further, in the second exhaust passage 22, the communication passage 3 is connected to the secondary exhaust turbo supercharger side turbine 32a.
An exhaust cut valve 41 is provided between the secondary exhaust turbo supercharger side turbine 32 and the secondary exhaust turbo supercharger side turbine 32.
The supply of exhaust gas to a is adjusted. Furthermore, the second exhaust passage 22 downstream of the exhaust cut valve 41 and the communication passage 33 are connected by a leakage passage 42. A leak valve 43 is provided in the leak passage 42 to adjust the supply of a small amount of exhaust gas to the secondary exhaust turbo supercharger side turbine 32a. In addition, the above communication path 3
3 and the exhaust passage 20 downstream of the primary and secondary exhaust turbo superchargers 31 and 32 are connected by a bypass passage 44. A wastegate valve 45 is provided in the bypass passage 44 to adjust the bypass amount of pressurized air to improve the boost pressure characteristics. Each of these valves 41, 43, 45
are driven by pressure-responsive actuators 46-48, respectively.

Furthermore, an intake cut valve 51 is provided immediately upstream of a portion of the second intake passage 12 where it joins the first intake passage 11 . In addition, the second intake passage 1
2 is the secondary exhaust turbo supercharger side turbine 3
A relief passage 52 is provided that bypasses 2a. This relief passage 52 has a relief valve 5.
3 is provided, and by opening the relief valve 53, the upstream side and the downstream side of the turbine 32a are communicated, and the pressurized air downstream of the compressor 32a is relieved. Each of these valves 51, 5
3 are driven by pressure-responsive actuators 56 and 57, respectively.

Further, a catalyst device 60 is provided downstream of the confluence of the first and second exhaust passages 21 and 22 in the exhaust passage 20 to purify the exhaust gas.

And each of the above actuators 46 to 48, 5
6 and 57 are controlled by a control unit 80. Furthermore, 81 is an air flow sensor provided in the intake passage 10 for detecting the intake flow rate;
82 is a throttle sensor for detecting the opening degree of the throttle valve 15, 83 is a boost pressure sensor provided in the intake passage 10 for detecting intake pressure, and 84 is a rotation speed for detecting the engine rotation speed. A sensor 85 is a water temperature sensor for detecting the water temperature of the engine; 86 is the intake cut valve 51;
This is a differential pressure sensor for detecting the differential pressure between the intake pressures on both sides. Each of these sensors 81-86 is connected to the control unit 80, respectively.

Next, the operation control of the control unit 80 will be explained based on the flow shown in FIG. first,
In step _S1 , signals from the sensors 81 to 86 are input, and in step _S2, it is determined whether the engine is in the low rotation range (specific operating range) shown in FIG.

Then, when the engine is in the low rotation range, that is, when the determination in step _S2 is YES, the operation of the secondary exhaust turbo supercharger 32 is stopped in steps _S1 to _S6 . i.e. step S ₃
and the exhaust cut valve ₄ in step S4.
1 to stop the operation of the secondary exhaust turbo supercharger 32, exhaust gas is intensively supplied to the primary exhaust turbo supercharger 31 to ensure high supercharging pressure, and the intake air is cut off in step _S5 . Close the valve 51 and open the intake passage 10 from the second intake passage 1.
1, and when the boost pressure falls below the set pressure in step _S6 , the relief valve 5
Open 3. This allows the relief valve 53 to relieve pressurized air downstream of the compressor in operating conditions where the intake flow rate is low and the pressure is high, such as when decelerating from high engine speed, thereby preventing intake air from flowing back into the compressor 32b. This prevents surging from occurring.

On the other hand, the engine is not in the low rotation range and step _S2
If the judgment is NO, step S ₇ ~ Step
The secondary exhaust turbo supercharger 32 is activated in S10. That is, in step _S7 , the leakage valve 43 is opened, and a small amount of exhaust gas is supplied to the secondary exhaust turbo supercharger 32 to perform a run-up of the turbine 32a. Then, when the boost pressure exceeds the set pressure in step _S8 , the relief valve 53 is closed and the exhaust cut valve 41 is opened in step _S9 , and when the differential pressure between the intake pressures on both sides of the intake cut valve 51 becomes small, the process proceeds to step S10. Open this intake cut valve 51 to operate the secondary exhaust turbo supercharger 32,
Primary and secondary exhaust turbo supercharger 3
The intake air is supercharged by both Nos. 1 and 32. This makes it possible to obtain an appropriate boost pressure while ensuring the intake air flow rate. Here, the reason why the relief valve 53 is closed before the exhaust cut valve 41 opens is because the relief valve 53 is closed when the exhaust cut valve 41 opens.
3 is open, the turbines 31a and 32a will idle and the rotational speed will suddenly increase, causing a sudden change in exhaust pressure and a large change in engine dilution gas, causing combustion fluctuations.

Note that it is possible to provide the exhaust cut valve 41 with the function of the leak valve 43, but in this embodiment, the exhaust cut valve 41 and the leak valve 43 are each made separate, so that the accuracy of the function of the leak valve 43 can be improved. is increasing.

Although not shown in the above flow, the waste gate valve 45 is also connected to the control unit 80.
The operation is controlled according to the boost pressure.

Here, the structure around the turbines 31a and 32a of each exhaust turbocharger 31 and 32 is shown in FIGS.
This will be explained based on the diagram. The above primary exhaust turbo supercharger 31 and secondary exhaust turbo supercharger 32
In this case, the turbine 31a,
The spiral directions of the scrolls 32a are the same, and both are provided in a direction in which the exhaust flow swirls clockwise.

And the primary exhaust turbo supercharger 31
and the secondary exhaust turbo supercharger 32 are arranged such that the discharge ports of the turbines 31a and 32a face each other. Furthermore, each turbine 31a, 32
The inlet a and the exhaust ports 5, 5, and 5 are connected by an exhaust manifold 25, and the exhaust manifold 25 forms a part of the exhaust passage 20.

Further, first and second exhaust passages 2 are connected to the discharge ports of each of the turbines 31a and 32a, respectively.
1 and 22 are directed downstream (upper side in Figure 2) after gathering, and these two turbines 31a and 32a
An exhaust gas collection section 23 is formed between the two to collect exhaust gas from each turbine discharge port.

In the case of the primary exhaust turbo supercharger 31, as shown in FIG.
The exhaust turbo supercharger 31 is arranged so that the exhaust flow FM from the turbine scroll and the exhaust flow FT within the turbine scroll are in the same direction around the axis of the exhaust turbo supercharger 31.
is connected to the exhaust manifold 25. On the other hand, in the case of the secondary exhaust turbo supercharger 32, as shown in FIG. 4, the exhaust flow FM from the exhaust manifold 25 and the exhaust flow FT in the turbine scroll are
The exhaust turbo supercharger 32 is connected to the exhaust manifold 25 so that the direction around the axis of the exhaust turbo supercharger 32 is opposite to that of the exhaust manifold 25 .

Therefore, the primary exhaust turbo supercharger 31
Since the spiral directions of the scrolls of the turbines 31a and 32a in the exhaust discharge direction of the secondary exhaust turbocharger 32 and the secondary exhaust turbocharger 32 are the same, the exhaust gas from each turbine discharge port of the two exhaust turbochargers 31 and 32 is the same. The swirling directions of the flows coincide downstream of the exhaust gas collecting portion 23, preventing interference of exhaust gas at the exhaust gas collecting portion 23, and reducing exhaust resistance.

In addition, the exhaust flow FM from the exhaust manifold 25
The direction of the exhaust flow FT in the turbine scroll around the axes of the exhaust turbo superchargers 31 and 32 is the same in the primary exhaust turbo supercharger 31 that is always active, and the secondary exhaust turbo supercharger that stops in a specific operating region is Since the direction is reversed in the charger 32, the flow of exhaust gas from the frequently used primary exhaust turbo supercharger 31 becomes smooth, increasing the efficiency of this supercharger, and effectively increasing the efficiency of the entire supercharging system. It turns out.

In addition, since the primary exhaust turbo supercharger 31 is made large and the secondary exhaust turbo supercharger 32 is made small, the region where only the primary exhaust turbo supercharger 31 supercharges (low rotation region ) becomes large, and the efficiency of the entire supercharging device is further improved.

The exhaust gas collecting part 23 is integrally provided with the turbine 32a on the secondary exhaust turbocharger side, and the turbine 31a on the primary exhaust turbocharger side is connected to the collecting part 23 by a flange via a gasket. It is connected. That is, when the engine speed increases from a low speed range and enters a high speed range, the secondary exhaust turbo supercharger side turbine 32a suddenly changes from a stopped state to an operating state and is subjected to a sudden thermal load. In this case, since such a connection structure is adopted, there is no gasket interposed between the secondary exhaust turbocharger side turbine 32a and the gathering portion 23, and the heat of the turbine 32a is transferred to the exhaust passage 2.
2, and the heat load on the turbine 32a can be reduced.

(Effects of the invention) As explained above, the engine exhaust turbocharging device of the present invention is equipped with a primary and a secondary exhaust turbosupercharger, the primary exhaust turbocharger is always operated, and the secondary exhaust The turbo supercharger is configured to stop in a specific operating range, and the spiral direction of the scroll of the turbine in the exhaust discharge direction is made to match between the primary exhaust turbo supercharger and the secondary exhaust turbo supercharger, A primary exhaust turbo supercharger and a secondary exhaust turbo supercharger are arranged with the discharge ports of the turbines facing each other, and the exhaust gas from each turbine discharge port is collected between the two exhaust turbo superchargers. and the direction of the exhaust flow from the exhaust manifold and the exhaust flow in the turbine scroll around the axis of the exhaust turbocharger is in the same direction for the primary exhaust turbocharger, and in the same direction for the secondary exhaust turbocharger. Since each exhaust turbo supercharger was connected to the exhaust manifold in the opposite direction,
The swirling direction of the exhaust flow from each turbine discharge port of the two exhaust turbo superchargers coincides downstream of the exhaust collecting part,
Exhaust interference at the exhaust gas collecting section is prevented, reducing exhaust resistance, and the exhaust flow of the frequently used primary exhaust turbocharger becomes smoother, increasing the efficiency of the turbocharger. This makes it possible to effectively improve the efficiency of the entire feeding device.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the present invention; Fig. 1 is a general schematic diagram, Fig. 2 is a plan view of the main parts of the engine, and Fig. 3 is a side view of the turbine of the primary exhaust turbocharger as seen from the compressor side. , Fig. 4 is a side view of the turbine of the secondary exhaust turbocharger seen from its discharge port side, Fig. 5 is a flowchart showing the operation control of the control unit, and Fig. 6 is an explanatory diagram showing the low rotation region. be. 23...Exhaust collection part, 25...Exhaust manifold, 31...Primary exhaust turbo supercharger, 32
...Secondary exhaust turbo supercharger, 31a...Turbine, 32a...Turbine.

Claims (1)

[Scope of utility model registration request] Equipped with a primary and secondary exhaust turbo supercharger that supercharges intake air using the energy of exhaust gas from the exhaust manifold, the primary exhaust turbo supercharger is always operated and the secondary exhaust turbo supercharger is stopped in a specific operating range. In the exhaust turbocharging device for an engine configured as above, the spiral direction of the scroll of the turbine in the direction of exhaust discharge is made to match between the primary exhaust turbocharger and the secondary exhaust turbocharger, and
The primary exhaust turbo supercharger and the secondary exhaust turbo supercharger are arranged with the discharge ports of the turbines facing each other, and the exhaust gas from each turbine discharge port is collected between the two exhaust turbo superchargers. In addition, the direction of the exhaust flow from the exhaust manifold and the exhaust flow in the turbine scroll around the axis of the exhaust turbocharger is the same in the primary exhaust turbocharger, and in the secondary exhaust turbocharger. An exhaust turbo supercharging device for an engine is characterized in that each exhaust turbo supercharger is connected to an exhaust manifold in opposite directions.