JP2003201927A - Negative pressure supplying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply steady negative pressure to an air pressure type booster by using an ejector, in a negative pressure supplying device for an engine equipped with a supercharger. <P>SOLUTION: A throttle valve 4, an intercooler 5, a turbo charger 6, and an air filter 7 are disposed in an intake pipe 3 of an engine main body 2. A first ejector 11 actuated by differential pressure between an upstream side and a downstream side of the throttle valve 4, and a second ejector 12 actuated by differential pressure between an upstream side and a downstream side of the turbo charger 6 are provided. Suction ports 11a, 12c of these ejectors 11, 12 are connected to a negative pressure chamber of the air pressure type booster 16 through check valves 14, 15. At the time of low speed operation of the engine, the vacuum degree of the negative pressure of the first ejector 11 is high, and at the time of high speed and high intensity operation, the vacuum degree of the negative pressure of the second ejector 12 is high. The check valves 14, 15 select the negative pressure having higher vacuum degree, thereby stably supplying negative pressure of high vacuum degree to the air pressure type booster regardless of an operating state. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative pressure supply device for supplying a negative pressure to a negative pressure operating device such as a pneumatic booster using an ejector by using an intake pressure of an engine of an automobile as a pressure source. It is a thing.

[0002]

2. Description of the Related Art Generally, a braking system for an automobile is provided with a pneumatic booster for increasing a braking force. The pneumatic booster generally uses the intake device of the engine as a negative pressure source, and introduces the negative intake pressure of the engine into the negative pressure chamber to generate thrust in the power piston by the pressure difference from the atmospheric pressure. To assist the operation force of the braking device.

There is also known a technique of increasing negative pressure supplied to a pneumatic booster by using an ejector. The ejector has a diffuser arranged downstream of the nozzle, and a negative pressure outlet is provided between them. When gas is flown from the nozzle side to the diffuser side, a high-speed jet flow is generated and the negative pressure outlet is formed. High negative pressure can be generated.
As a technique of supplying a negative pressure to a pneumatic booster using an ejector, for example, in Patent Document 1, in addition to an ejector arranged in parallel with a throttle valve, a difference between an engine exhaust pressure and an atmospheric pressure is disclosed. An example in which an ejector is driven by pressure to generate a negative pressure, Patent Document 2 discloses an example in which an ejector is arranged in parallel with a throttle valve so that the amount of air supplied to the ejector during no-load operation can be adjusted. 3, an example in which operating air of an ejector is caused to flow from the atmosphere to an intake pipe, and Patent Document 4 discloses an example in which an ejector arranged in parallel with a throttle valve is integrally formed with a pneumatic booster. .

[0004]

[Patent Document 1] Japanese Patent Publication No. 37-18907

[Patent Document 2] JP-A-54-13814

[Patent Document 3] Japanese Patent Laid-Open No. 59-50849

[Patent Document 4] JP-A-60-29366

[0005]

By the way, conventionally, in order to obtain a high output with a small engine, it has been widely used to use a supercharger such as a turbocharger. In an engine equipped with a supercharger, intake air is pressurized by the supercharger, so that the negative pressure of the intake pipe may decrease. In particular, during high load operation in which the supercharging pressure is high and the throttle opening is large, the amount of negative pressure supplied to the pneumatic booster is likely to decrease.

The present invention has been made in view of the above points, and provides a negative pressure supply device capable of supplying a stable negative pressure using an ejector in an engine equipped with a supercharger. The purpose is to

[0007]

In order to solve the above problems, the invention according to claim 1 supplies negative pressure to a negative pressure operating device by using intake pressure of an engine equipped with a supercharger as a pressure source. A negative pressure supply device, the first ejector operating by a differential pressure between the upstream side and the downstream side of the throttle valve, and the first ejector operating by a differential pressure between the upstream side and the downstream side of the supercharger.
It is characterized by comprising two ejectors and a selection means for supplying one of the negative pressures generated by the first and second ejectors having a higher degree of vacuum to the negative pressure operating device. With this configuration, the negative pressure generated by the larger pressure difference between the upstream side and the downstream side of the throttle valve and the differential pressure between the upstream side and the downstream side of the supercharger is reduced to a negative pressure. Actuator can be supplied. The invention according to claim 2 is a negative pressure supply device for supplying a negative pressure to a negative pressure operating device by using an intake pressure of an engine equipped with a supercharger as a pressure source,
An ejector, a first selection unit that selects the higher pressure of the atmospheric pressure and the supercharging pressure of the supercharger and supplies it to the inlet of the ejector, and the low pressure of the intake manifold pressure and the atmospheric pressure of the engine. And a second selecting means for selecting one of them and supplying the selected one to the outlet of the ejector. With this configuration,
A negative pressure actuating device generates a negative pressure generated by operating the ejector by the differential pressure between the higher pressure of the atmospheric pressure and the supercharging pressure and the lower pressure of the intake manifold pressure and the atmospheric pressure. Can be supplied to. According to a third aspect of the present invention, in the negative pressure supply device according to the second aspect, the supercharging pressure of the supercharger is supplied to the negative pressure actuating device so that a differential pressure between the supercharging pressure and the negative pressure. The negative pressure actuating device is actuated by. With this configuration, a large pressure can be generated in the negative pressure operating device by the pressure difference between the supercharging pressure and the negative pressure. A negative pressure supply device according to a fourth aspect of the present invention is characterized in that, in the configuration according to any one of the first to third aspects, the selection means is a check valve. With this configuration,
High pressure and low pressure are selected by opening and closing the check valve. The negative pressure supply device according to the invention of claim 5 is the above-mentioned claim 1 to 4
In any one of the above configurations, a gas-liquid separating means is provided in a pipe line connecting the intake pipe side and the ejector side or the negative pressure operating device side. With this configuration, the air supplied from the intake pipe side to the ejector side or the negative pressure operating device side can be separated into gas and liquid. The negative pressure supply device according to the invention of claim 6 is the above-mentioned claim 5.
In the above configuration, the engine equipped with the supercharger is equipped with a PCV valve for returning blow-by gas generated in the engine to the intake pipe, and a pipe line for supplying atmospheric pressure to the ejector. Is connected to the intake pipe at a position downstream of the return port of the PCV valve to the intake pipe. With this configuration, the blow-by gas from the PCV valve side is not mixed with the atmosphere supplied to the ejector.
Further, in the negative pressure supply device according to the invention of claim 7, in the configuration according to any one of claims 1 to 6, the engine provided with the supercharger is configured to discharge exhaust gas generated in the engine to the intake pipe. EGR valve for recirculation to
The connection port to the intake pipe of the conduit for supplying the intake manifold pressure of the engine to the ejector is
It is characterized in that it is arranged on the upstream side of the recirculation port of the EGR valve to the intake pipe. With this configuration, the exhaust gas recirculated to the intake pipe by the EGR valve does not flow to the ejector side.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. The negative pressure supply device 1 according to the present embodiment uses the intake pressure of an automobile engine as a pressure source,
Negative pressure is supplied to the pneumatic booster of the braking system.Through the intake pipe 3 of the engine body 2, from the engine body 2 side, the throttle valve 4, the intercooler 5, the compressor C of the turbocharger 6, and the air filter. 7 is arranged and the air filter 7 is open to the atmosphere. Further, the exhaust pipe 8 of the engine main body 2 includes a turbine T of the turbocharger 6 and a catalytic converter 9 in order from the engine main body 2 side.
And the muffler 10 is arranged so that the muffler 10 is open to the atmosphere.

Between the compressor C of the turbocharger 6 of the intake pipe 3 and the intercooler 5, inlets 11a and 12a of the first and second ejectors 11 and 12 are connected. The outlet 11b of the first ejector 11 is connected to the throttle valve 4 via the check valve 13.
Is connected to the downstream side (intake manifold). The check valve 13 blocks the flow from the intake pipe 3 side to the first ejector 11 side. The outlet 12b of the second ejector 12 is connected between the air filter 7 of the intake pipe 3 and the compressor C of the turbocharger 6. 1st and 2nd ejector 1
The suction ports 11C and 12C of 1, 12 are respectively connected to the pneumatic booster 1 of the braking system of the vehicle through check valves 14 and 15 (selection means).
It is connected to the negative pressure chamber of 6 (negative pressure actuator). Check valve 14,
Reference numerals 15 respectively prevent the flow from the pneumatic booster 16 side to the first and second ejector 11 and 12 sides.

Although not shown here, the pneumatic booster 16 includes a negative pressure chamber (constant pressure chamber) defined by a power piston and a variable pressure chamber, and is connected to an input rod connected to a brake pedal or the like. Depending on the input of (the brake operating force of the driver), the atmosphere is introduced into the variable pressure chamber, and the thrust force is generated in the power piston by the differential pressure generated between the negative pressure chamber and the variable pressure chamber, and the servo force is added to the brake operating force. Is generally given.

The first and second ejectors 11 and 12 are, as shown in FIG. 2, a nozzle arranged on the inlet 11a, 12a side and an outlet 1
The diffuser placed on the 1b, 12b side is combined, and the suction ports 11c, 12c are made to communicate between them.
By causing air to flow from the nozzles on the side of 1a, 12a toward the diffuser on the side of outlets 11b, 12b, a negative pressure is generated between them, and this negative pressure sucks air from the suction ports 11c, 12c. The first and second ejectors 11 and 12 form a single Laval nozzle having an inlet in which the nozzle and the diffuser are smoothly reduced and an enlarged outlet in a loose divergence angle. Reaches the speed of sound, and a flow speed exceeding the speed of sound occurs in the downstream part. Since the static pressure decreases almost in proportion to the square of the flow velocity, the inlet 11a, 1
2a side is atmospheric pressure, outlet 11b, 12b side is negative pressure of 200mmHg, and air volume from suction port 11c, 12c is 0, 360mmHg at throat section T
A negative pressure exceeding 450 mmHg can be generated in the downstream portion, and this negative pressure is taken out from the suction ports 11c and 12c. Thereby, by the pressure difference between the inlet 11a, 12a side and the outlet 11b, 12b side, a negative pressure lower than the outlet 11b, 12b side can be obtained, the inlet 11a, 12a side positive pressure, the outlet 11b, 12b side. Even at atmospheric pressure, high negative pressure can be obtained from the suction ports 11c and 12c.

Then, the first and second ejectors 11 and 12
As shown in FIG. 3, the nozzle and the diffuser having inlets 11a, 12a, outlets 11b, 12b and suction ports 11c, 12c are formed in a flat plate shape, and are arranged on the same plane to be integrally formed in one case 17. However, by connecting the inlets 11a and 12a to each other through the passage 18, they can be easily integrally formed by injection molding of synthetic resin, cutting of a plate material, or the like. Also, the first
Also, by providing check valves 13, 14, 15 (not shown in FIG. 3) integrally in the case 17 in which the second ejectors 11 and 12 are integrally formed, downsizing and simplification of piping can be achieved. Can be achieved.

The operation of the present embodiment configured as described above will be described below. The air sucked from the air filter 7 is pressurized by the compressor C of the turbocharger 6 and cooled by the intercooler 5, and then the flow rate is controlled by the throttle valve 4 to be supplied to the intake manifold of the engine body 2. . The exhaust gas discharged from the exhaust manifold of the engine body 2 drives the turbine T of the turbocharger 6, is purified by the catalytic converter 9, and is discharged to the atmosphere via the muffler 10. In the turbocharger 6, the compressor C is driven by the turbine T driven by the exhaust gas to pressurize the intake air, so that the efficiency of filling the combustion chamber with the intake air can be increased and a high output can be obtained. it can.

During low-speed operation or low-load operation of the engine, the supercharging pressure by the turbocharger 6 is low, and due to the throttle of the throttle valve 4, the inside of the intake manifold of the engine body 2 becomes negative pressure. Therefore, in the second ejector 12 connected to the turbocharger 6 side, the differential pressure between the inlet 12a and the outlet 12b becomes small, and the negative pressure (vacuum degree) generated at the suction port 12c becomes low. On the other hand, in the first ejector 11 connected to the throttle valve 4 side, the inlet 11a and the outlet 11b are
The differential pressure between and becomes large, and the negative pressure (vacuum degree) generated at the suction port 11c becomes high. Therefore, the check valve 15 on the second ejector 12 side is closed, the check valve 14 on the first ejector 11 side is opened, and the suction port 11c of the first ejector 11 having a high degree of vacuum causes the negative pressure of the pneumatic booster 16 to be reduced. Negative pressure is supplied to the pressure chamber.

Further, during high speed and high load operation of the engine,
Since the supercharging pressure by the turbocharger 6 is high and the throttle of the throttle valve 4 is small (the throttle opening is large),
The supercharged intake air may cause a positive pressure in the intake manifold of the engine body 2. At this time, the inlet 12a of the second ejector 12 connected to the turbocharger 6 side
The side becomes high pressure due to supercharging pressure, and the outlet 12b side becomes almost atmospheric pressure, so the differential pressure between the inlet 12a and the outlet 12b becomes large, and the negative pressure (vacuum degree) generated at the suction port 12c becomes high. Become. On the other hand, in the first ejector 11 connected to the throttle valve 4 side, the throttle of the throttle valve 4 is small and the intake manifold has a positive pressure due to supercharging pressure.
The differential pressure between 11a and the outlet 11b is small, and the negative pressure (vacuum degree) generated at the suction port 11c is low. Therefore, the check valve 15 on the second ejector 12 side opens, and the check valve 1 on the first ejector 11 side opens.
4 is closed, and the suction port 12c of the second ejector 12 with high vacuum is
The negative pressure is supplied to the negative pressure chamber of the pneumatic booster 16. If the inside of the intake manifold becomes positive, or
When the engine is stopped, the fuel gas is discharged from the first ejector 11
The check valve 13 can prevent backflow to the outlet 11b.

In this manner, one of the first and second ejectors 11 and 12 having a higher degree of vacuum is selected in accordance with the operating state of the engine (the operating state of the turbocharger 6) to extract the negative pressure. Therefore, regardless of the operating state of the engine, a negative pressure with a high degree of vacuum can always be stably supplied to the pneumatic booster 16.

Next, a second embodiment of the present invention will be described with reference to FIG.
And it demonstrates with reference to FIG. In the following description, the same parts as those in the first embodiment are designated by the same reference numerals, and only different parts will be described in detail.

As shown in FIG. 4, in the negative pressure supply device 19 according to the second embodiment, the inlet 11a of the first ejector 11 is an intake pipe.
3 turbocharger 6 compressor c and air filter 7
It is connected between and.

Then, the first and second ejectors 11, 12
As shown in FIG. 5, the nozzle and the diffuser having inlets 11a, 12a, outlets 11b, 12b and suction ports 11c, 12c are formed in a flat plate shape, and are arranged on the same plane to be integrally formed in one case 20. By integrally forming the first ejector inlet 11a and the second ejector 12b of the second ejector, it is possible to easily perform integral molding by injection molding of synthetic resin, cutting of a plate material, or the like. In this case, since the jet flow generated by the second ejector 12 flows into the inlet 11a of the first ejector 11 at a high speed, the degree of vacuum of negative pressure generated at the suction port 11c of the first ejector 11 can be increased. it can. Also, the first and second
The case 20 in which the ejectors 11 and 12 are integrally formed is further provided with the check valves 13, 14 and 15 (not shown in FIG. 5) integrally to achieve downsizing and simplification of piping. You can

According to the second embodiment configured as described above, the first ejector 11 includes the throttle valve 4 of the intake pipe 3.
A negative pressure can be generated in the suction port 11c by the pressure difference between the downstream side of the above and the upstream side of the compressor C of the turbocharger 6, and the same operation and effect as those of the first embodiment can be obtained.

Next, a third embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. In the following description, the same parts as those in the second embodiment are designated by the same reference numerals, and only different parts will be described in detail.

As shown in FIG. 6, in the negative pressure supply device 21 of this embodiment, the second ejector 12 and the check valve 15 are omitted, and the inlet 11a of the first ejector 11 (ejector) is
It is connected between the compressor C of the turbocharger 6 of the intake pipe 3 and the air filter 7 via the check valve 23 (first selecting means), and also intakes via the check valve 24 (first selecting means). It is connected between the intercooler 5 of the tube 3 and the compressor C of the turbocharger 6. The check valves 23 and 24 are used for the first ejector 11
The flow from the inlet 11a side to the intake pipe 3 side is blocked. Further, the outlet 11b of the first ejector 11 is connected to the check valve 25 (second
It is connected between the compressor C of the turbocharger 6 of the intake pipe 3 and the air filter 7 via the selection means). The check valve 25 blocks the flow from the intake pipe 3 side to the outlet 11b side of the first ejector 11.

With such a configuration, the check valve 2
By 3,24, of the inlet side (atmospheric pressure) and the outlet side (supercharging pressure of the compressor C) of the compressor C of the turbocharger 6 of the intake pipe 3, the one with the higher pressure is selected, and the first ejector 11 Supply to the inlet 11a. Further, the air flowing out from the outlet 11b of the first ejector 11 is compressed by the check valves 13 (second selection means) and 25 among the downstream side of the throttle valve 4 of the intake pipe 3 and the downstream side of the air filter 7. Flows to the lower side of.

As a result, during low-speed operation or low-load operation of the engine, the supercharging pressure by the turbocharger 6 is low, and the throttle of the throttle valve 4 causes a negative pressure in the intake manifold of the engine body 2. The stop valves 24 and 25 are closed, the check valves 13 and 23 are opened, and the first ejector 11 operates due to the differential pressure between the downstream side of the air filter 7 and the downstream side of the throttle valve 4 of the intake pipe 3, Negative pressure is supplied to the negative pressure chamber of the pneumatic booster 16 from the suction port 11c via the check valve 14.

When the engine is operated at high speed under high load,
Since the supercharging pressure by the turbocharger 6 is high and the throttle of the throttle valve 4 is small (the throttle opening is large),
The supercharged intake air may cause a positive pressure in the intake manifold of the engine body.

In this case, the check valve 23 and the check valve 13 are closed, the check valve 24 and the check valve 25 are opened, and the difference between the discharge pressure of the compressor C of the turbocharger 6 and the atmospheric pressure causes 1 The ejector 11 operates and the check valve
Negative pressure is supplied to the negative pressure chamber of the pneumatic booster 16 via 14.

In this way, the check valves 13, 23, 24, 2 are selected according to the operating state of the engine (the operating state of the turbocharger 6).
5, the pressure source can be selected so that the differential pressure between the inlet 11a side and the outlet 11b side of the first ejector 11 becomes large, so that the pneumatic booster 16 is always provided regardless of the operating state of the engine. It is possible to stably supply a negative pressure with a high degree of vacuum.

In the third embodiment, when the engine is operating at a low speed, the boost pressure of the compressor C of the turbocharger 6 is substantially equal to the atmospheric pressure. Therefore, the check valves 23, 24
And omits the inlet 11a of the first ejector 11 from the compressor.
Even if it is directly connected to the downstream side of C, it is possible to obtain substantially the same effect as above.

In the first to third embodiments described above, a pipe line for connecting the negative pressure chamber of the pneumatic booster 16 directly to the intake manifold of the engine body via the check valve is added to increase the pressure of the intake manifold. Is lower than the pressure in the negative pressure chamber, the negative pressure can be directly supplied from the intake manifold to the negative pressure chamber of the pneumatic booster regardless of the ejector.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
It will be described with reference to FIGS. In the following description, the same parts as those in the third embodiment are designated by the same reference numerals, and only different parts will be described in detail.

As shown in FIG. 7, in the negative pressure supply device 30 of this embodiment, the pneumatic booster 16 has a negative pressure defined by a power piston 31 as compared with the third embodiment. In addition to the chamber 32 (constant pressure chamber) and the variable pressure chamber 33, it has a positive pressure chamber 34 that stores positive pressure, and depending on the input to the input rod 36 connected to the brake pedal 35 (the brake operating force of the driver). , The positive pressure in the positive pressure chamber 34 is introduced into the transformer chamber 33, and the negative pressure chamber 32 and the transformer chamber 33 are
A thrust force is generated in the power piston by the pressure difference generated between and, and a servo force is applied to the brake operation force. By introducing a positive pressure into the variable pressure chamber 33 in this way, the differential pressure between the variable pressure chamber 33 and the negative pressure chamber 32 can be increased, so that a normal pneumatic booster that introduces the atmosphere into the variable pressure chamber can be used. Can generate a large servo force. In FIG. 7, reference numeral 37 is a vehicle body panel that divides the engine room and the vehicle compartment, and 38 is a master cylinder.

The inlet 11a of the first ejector 11 is connected to the intercooler 5 of the intake pipe 3 and the throttle valve 4 via the check valve 24.
It is connected between and (on the downstream side of the intercooler 5). The positive pressure chamber 34 of the pneumatic booster 16 is connected between the air filter 7 of the intake pipe 3 and the compressor C of the turbocharger 6 via the check valve 39 and the check valve 23, and Via the check valve 39 and the check valve 24, the intercooler 5 of the intake pipe 3
And the throttle valve 4 (downstream of the intercooler 5). The check valve 39 is installed on the intake pipe 3 from the positive pressure chamber 34 side.
It blocks the flow of air to the side. Further, the negative pressure chamber 32 of the pneumatic booster 16 is directly connected between the throttle valve 4 of the intake pipe 3 and the engine body 2 via the check valve 40 and the check valve 13. The check valve 40 blocks the flow of air from the intake pipe 3 side to the negative pressure chamber 32 side.

Although not shown and described in the third embodiment, the ISC valve 41 (idle speed control valve) bypassing the upstream and downstream of the throttle valve 4 of the intake pipe 3 and the compressor of the turbocharger 6 are omitted.
Air bypass valve 42 that bypasses the upstream and downstream of C, EGR valve 43 that recirculates exhaust gas of engine body 2 to the intake side
(Exhaust gas recirculation valve) and PCV valve 44 (positive crankcase ventilation valve) that recirculates blow-by gas of engine body 2 to intake pipe 2 are provided. Here, as indicated by symbol A in FIG. 7, the connecting portion of the EGR valve 43 to the intake pipe 3 is arranged on the downstream side of the connecting portion of the pipe line in which the check valve 13 is provided. In addition, as indicated by symbol B in FIG. 7, PCV
The connection portion of the valve 44 to the intake pipe 3 includes a check valve 23 and a check valve 2
The pipes 5 are arranged on the downstream side of the connecting portions of the respective pipes.

The ISC valve 41 is for controlling the bypass air amount of the throttle valve 4 to stabilize the idling speed of the engine body 2. Air bypass valve
Reference numeral 42 is for reducing the generation of surge noise by relieving the boost pressure of the turbocharger 6 during deceleration. The EGR valve 43 is for appropriately recirculating exhaust gas into the combustion chamber to lower the combustion temperature and suppress the generation of nitrogen oxides. Further, the PCV valve 44 is for preventing the blow-by gas from being released into the atmosphere by appropriately reducing the blow-by gas to the intake pipe 3 and burning it.

An oil mist trap 45 (gas-liquid separating means) is provided in the conduit between the check valve 24 and the intake pipe 3. As shown in FIG. 8, the oil mist trap 45 has a large diameter portion 47 formed in a part of a pipe line 46, and a porous layer 48 such as a sintered metal or a wire mesh is provided on the inner peripheral surface thereof. Pipeline 46
The flow velocity of the air flowing therethrough is reduced, gas-liquid separation is performed, and high viscosity components such as oil mist in the air are attached to the porous layer 48 and collected.

With such a configuration, the check valve 23
The check valve 24 and the supercharging pressure of the turbocharger 6 or the higher pressure of the atmospheric pressure are used for the positive pressure chamber of the pneumatic booster 16.
The air can be supplied to the positive pressure chamber 34 by the supercharge of the turbocharger 6, and the positive pressure air can be accumulated in the positive pressure chamber 34. This makes it possible to increase the differential pressure between the negative pressure chamber 32 and the variable pressure chamber 33 and increase the servo force. Also,
Since the negative pressure chamber 32 is directly connected to the intake pipe 3 via the check valve 40 and the check valve 13, even if the check valve 14 or the ejector 11 should fail, the negative pressure chamber 32 can be removed from the intake pipe 3. , Directly,
The intake negative pressure can be introduced into the negative pressure chamber 32, and the operation of the pneumatic booster 16 can be ensured.

As shown by the symbol A in FIG. 7, the EGR valve 43
Since the connecting portion of the intake pipe 3 to the intake pipe 3 is arranged on the downstream side of the connecting portion of the pipe line provided with the check valve 13, exhaust gas containing high-viscosity components such as oil mist is on the check valve 13 side. Flow to
The functions of the check valve 13 and the like are not deteriorated. Also, FIG.
As indicated by the symbol B therein, the connection portion of the RCV valve 44 to the intake pipe 3 is arranged on the downstream side of the connection portion of each of the pipelines provided with the check valve 23 and the check valve 25. Therefore, blow-by gas containing high-viscosity components such as oil mist will not be discharged by the check valve 23.
The flow does not flow to the first ejector 11, the check valve 39, and the positive pressure chamber 34 of the pneumatic booster 16 via the valve to reduce their functions.

Further, the compressor C of the turbocharger 6
The supercharged air is cooled by the intercooler 5 and then passes through the oil mist trap 45 to remove high-viscosity components such as oil mist, and then to the first ejector 11 via the check valve 24. Since the pressure is supplied to the positive pressure chamber 34 of the pneumatic booster 16 via the check valve 39, the functions of the check valves 24, 39, the ejector 11 and the pneumatic booster 16 due to high viscosity components in the air Can be prevented.

Further, a pipeline for supplying air to the positive pressure chamber 34 of the pneumatic booster 16 is provided on the engine room side of the vehicle body panel 37, and when the pneumatic booster 16 is in operation, Therefore, since the atmosphere is not introduced into the transformer chamber 33, the operating noise can be reduced.

Next, after opening the throttle valve 4 and continuing to supercharge the turbocharger 5, the throttle valve 4 is closed and the negative pressure chamber 32 of the pneumatic booster 16 when the brake is operated The pressures in the chamber 33 and the positive pressure chamber 34 will be described with reference to FIG.

In FIG. 9, is the outlet pressure of the turbocharger 6, is the intake pressure of the engine body 2, is the negative pressure chamber 32 of the pneumatic booster 16, that is, the suction port 1 of the first ejector 11.
1c pressure, positive pressure chamber 34 pressure, transformer chamber 33 pressure,
Is the pressure in the variable pressure chamber of the pneumatic booster of the third embodiment, is the pressure in the negative pressure chamber of the conventional pneumatic booster when the ejector is not provided, is the conventional pressure type when the ejector is not provided Indicates the pressure in the transformer room of the booster.

In the supercharging state, the differential pressure between the negative pressure chamber 32 and the positive pressure chamber 34 becomes a, and the differential pressure b between the negative pressure chamber and the atmospheric pressure in the third embodiment and the negative pressure when the ejector is not provided. A pressure difference larger than the pressure difference c between the pressure chamber and the atmospheric pressure can be obtained.
Further, when the brake is operated in the idling state after closing the throttle valve 4, the differential pressure between the negative pressure chamber 32 and the positive pressure chamber 34 becomes a ′, which is larger than the negative pressure chamber in the third embodiment. It is possible to obtain a pressure difference larger than the pressure difference b ′ with the atmospheric pressure and the pressure difference c ′ between the negative pressure chamber and the atmospheric pressure when the ejector is not provided. In this way, a large differential pressure can be stably obtained before and after the operation of the brake.

At this time, the positive pressure chamber is activated by the operation of the brake.
By supplying positive pressure air from the variable pressure chamber 33 to the variable pressure chamber 33, the pressure in the variable pressure chamber 33 can be rapidly increased to generate a predetermined differential pressure between the variable pressure chamber 32 and the negative pressure chamber 32. The time t1 is shorter than the response time t2 of the third embodiment, and the responsiveness of the brake operation can be improved.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
A description will be given with reference to 0. In the following description, the same parts as those in the fourth embodiment are designated by the same reference numerals, and only different parts will be described in detail.

In the negative pressure supply device 49 of this embodiment, the inlet 11a of the ejector 11 and the positive pressure chamber 34 of the pneumatic booster 16 are used.
Is connected to an air filter 50 different from the air filter 7 of the intake pipe 3 via the check valve 23 and is open to the atmosphere.
Further, an ejector unit 51 in which the ejector 11, the check valves 14, 23, 24, 39, 40, the oil mist trap 45, and the air filter 50 are integrated is provided integrally with the pneumatic booster 16. With this configuration, the piping of the connecting pipe between the engine body 2 side and the pneumatic booster 16 side can be simplified, and the mountability on the vehicle can be improved.

In the first to fifth embodiments described above, an example in which a turbocharger is used as a supercharger has been described, but the present invention is not limited to this, and another supercharger such as a supercharger. It can be similarly applied to the one using. Further, although the pneumatic booster is illustrated as the negative pressure operating device, the negative pressure operating device is not limited to this, and another negative pressure operating device using a negative pressure as a drive source may be used.

Further, the oil mist trap 45, which is the gas-liquid separating means provided in the fourth and fifth embodiments, is the same as the first mist trap.
Also in the third embodiment, the high-viscosity component in the air is removed by providing the intake pipe 3 side and the first and second ejectors 11 and 12 or the pneumatic booster 16 side in the pipe line that connects them. It is possible to prevent malfunction of the first and second ejectors 11 and 12 or the pneumatic booster 16 due to these high-viscosity components.

[0048]

As described in detail above, according to the negative pressure supply device of the first aspect of the present invention, the differential pressure between the upstream side and the downstream side of the throttle valve is controlled by the first and second ejectors and the selecting means. Since the negative pressure generated by the larger pressure difference between the upstream side and the downstream side of the supercharger can be supplied to the negative pressure operating device, the negative pressure is always applied regardless of the operating state of the engine. A negative pressure having a high degree of vacuum can be stably supplied to the pressure actuating device. According to the negative pressure supply device of the invention of claim 2, by the first and second selecting means, the higher pressure of the atmospheric pressure and the supercharging pressure and the lower pressure of the intake manifold pressure and the atmospheric pressure are used. Because the negative pressure can be supplied to the negative pressure actuator by operating the ejector by the differential pressure from the pressure of one side, the negative pressure actuator always has a high vacuum level regardless of the operating condition of the engine. The pressure can be stably supplied. According to the negative pressure supply device of the invention of claim 3, the above-mentioned claim 2
In addition to the above effect, a large force can be generated in the negative pressure operating device by the pressure difference between the supercharging pressure and the negative pressure. According to the negative pressure supply device of the invention of claim 4, in addition to the effects of claims 1 to 3, high pressure and low pressure can be selected by opening and closing the check valve. According to the negative pressure supply device of the invention of claim 5, in addition to the effects of claims 1 to 4, the air supplied from the intake pipe side to the ejector side or the negative pressure operating device side is separated into gas and liquid. Therefore, it is possible to prevent malfunction of the ejector or the negative pressure operating device due to oil mist or the like. According to the negative pressure supply device of the invention of claim 6, in addition to the effect of claim 5, blow-by gas recirculated from the PCV valve to the intake pipe is not mixed with the atmosphere supplied to the ejector. It is possible to prevent malfunction of the ejector due to oil mist contained in the blow-by gas. According to the negative pressure supply device of the invention of claim 7, in addition to the effects of claims 1 to 6, the exhaust gas recirculated to the intake pipe by the EGR valve flows from the intake manifold side to the ejector side. Therefore, it is possible to prevent the ejector, the check valve, and the like from being deteriorated by harmful components of the exhaust gas such as nitrogen oxides, and to improve their durability.

[Brief description of drawings]

FIG. 1 is a block diagram showing a negative pressure supply device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a schematic configuration of an ejector used in the device of FIG.

FIG. 3 is a plan view of a case in which first and second ejectors used in the device of FIG. 1 are integrally formed.

FIG. 4 is a block diagram showing a negative pressure supply device according to a second embodiment of the present invention.

5 is a plan view of a case in which first and second ejectors used in the apparatus of FIG. 4 are integrally formed.

FIG. 6 is a block diagram showing a negative pressure supply device according to a third embodiment of the present invention.

FIG. 7 is a block diagram showing a negative pressure supply device according to a fourth embodiment of the present invention.

8 is a vertical sectional view of an oil mist trap of the device shown in FIG.

9 is a graph showing changes in pressure of each part during operation of the negative pressure supply device shown in FIG.

FIG. 10 is a block diagram showing a negative pressure supply device according to a fifth embodiment of the present invention.

[Explanation of symbols]

1,19,21 Negative pressure supply device 4 Throttle valve 6 Turbocharger (supercharger) 11 1st ejector (ejector) 12 Second ejector 14,15 Check valve (selection means) 16 barometric pressure booster (negative pressure actuator) 23,24 Check valve (first selection means) 13,25 Check valve (second selection means)

Claims (7)

[Claims] 1. A negative pressure supply device for supplying a negative pressure to a negative pressure operating device by using an intake pressure of an engine equipped with a supercharger as a pressure source, the differential pressure between an upstream side and a downstream side of a throttle valve. The first ejector that operates, the second ejector that operates by the differential pressure between the upstream side and the downstream side of the supercharger, and the negative pressure generated by the first and second ejectors, whichever has a higher degree of vacuum, A negative pressure supply device, comprising: a selection unit that supplies the negative pressure operation device. 2. A negative pressure supply device for supplying a negative pressure to a negative pressure operating device by using an intake pressure of an engine provided with a supercharger as a pressure source, the ejector, atmospheric pressure and supercharge of the supercharger. First selecting means for supplying the higher pressure to the inlet of the ejector and selecting the lower pressure of the intake manifold pressure and atmospheric pressure of the engine and supplying it to the outlet of the ejector A negative pressure supply device comprising: a second selection means. 3. The supercharging pressure of the supercharger is supplied to the negative pressure operating device, and the negative pressure operating device is operated by a pressure difference between the supercharging pressure and the negative pressure. The negative pressure supply device described in 2. 4. The negative pressure supply device according to claim 1, wherein the selection unit is a check valve. 5. The gas-liquid separating means is provided in a pipe line connecting the intake pipe side and the ejector side or the negative pressure operating device side. Negative pressure supply device. 6. The engine including the supercharger includes a PCV valve for returning blow-by gas generated in the engine to the intake pipe, and a pipe for supplying atmospheric pressure to the ejector. The connection port of the passage to the intake pipe is
6. The negative pressure supply device according to claim 5, wherein the negative pressure supply device is arranged downstream of a return port of the PCV valve to the intake pipe. 7. An engine provided with the supercharger is provided with an EGR valve for recirculating exhaust gas generated in the engine to the intake pipe, and the ejector is provided with an intake manifold pressure of the engine. 7. The connection port of the pipeline for supplying to the intake pipe is arranged upstream of the recirculation port of the EGR valve to the intake pipe. Negative pressure supply device according to.