JPH0415951Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a boost pressure variable device for a turbocharger.

[Prior Art] A reciprocating internal combustion engine a shown in Fig. 2 is equipped with a turbocharger b, and its exhaust energy is used to drive a turbine c. Air is compressed to increase the amount of air supplied to the internal combustion engine a for supercharging, thereby increasing output.

Furthermore, as the engine speed increases, the rotation speed of the turbine c also increases, and the boost pressure sent from the compressor d to the internal combustion engine a increases too much, causing engine trouble. Therefore, the boost pressure is reduced by the waste gate valve e. When the pressure exceeds a predetermined value, a portion of the exhaust gas introduced into the turbine c is released to the outside to stabilize the boost pressure.

[Problem that the invention aims to solve] For turbo engines used in vehicles that drive in areas with large altitude differences, if the boost pressure is set for flat terrain, sufficient output cannot be obtained at high altitudes due to the thin atmosphere. Also, if the boost pressure is set for high altitudes, the engine's explosion pressure will be excessive on flatlands, causing engine trouble.

The same is true for general turbo cars; it is desirable to increase boost and torque during sudden acceleration, but if a high boost pressure is set for this purpose, engine trouble will occur during normal driving.

[Means for Solving the Problems] In order to solve the above-mentioned conventional problems, the present invention provides a compressor outlet on the diaphragm head side of the actuator that opens and closes the waste gate valve provided in the turbine chamber of the turbocharger. A boost pressure introduction pipe connected to the pipe and a sensing pipe taken out from the shroud of the compressor impeller are connected in a switchable manner, and a branch pipe equipped with an orifice and a valve is connected to the sensing pipe, and the sensing pipe and the actuator are connected in a switchable manner. A boost pressure variable device for the turbocharger was constructed by connecting a branch pipe with a valve to the spring chamber.

[Function] In all ranges where the turbocharger rotates from low speed to high speed, the compressed air pressure in the shroud of the compressor impeller is always lower than the compressed air pressure in the compressor outlet pipe, so the shroud is driven by the wastegate valve. The pressure of the actuator can be connected via the sensing tube on the diaphragm head side of the actuator, or in this state, some of the pressure in the sensing tube can be leaked through the orifice or guided to the spring chamber side of the actuator. The operating pressure can be switched in multiple stages, and altitude correction can be easily performed.

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

FIG. 1 shows an embodiment of the present invention, in which a head 5 side of a diaphragm 4 of an actuator 3 that opens and closes a waste gate valve 1 provided in a turbine chamber of a turbocharger via a lever device 2;
The compressor outlet pipe 6 of the turbocharger is connected through a boost pressure introduction pipe 7, and a three-way valve 8 is provided in the middle of the boost pressure introduction pipe 7.
Shroud part 10 of compressor housing 9
The other end of a sensing tube 12 connected to a guide hole 11 bored at a predetermined position is switchably connected to the boost pressure introduction tube 7.

Further, branch pipes 13 and 14 are provided at two locations in the middle of the sensing pipe 12, a valve 15 is provided in the middle of one of the branch pipes 13, and the other end of the branch pipe 13 is connected to the spring chamber 16 side of the actuator 3. However, an orifice 17 and a solenoid valve 18 are provided in the middle of the other branch pipe 14, and the end of the branch pipe 14 is connected to the intake side of the compressor and opened to the atmosphere.

With the above configuration, for example, when driving on low ground, the three-way valve 8 can be set so that the boost pressure introduction pipe 7 communicates with the actuator 3.
As the altitude increases, the atmospheric pressure decreases, so it is necessary to further increase the boost, but if this continues, the actuator 3 will operate, the wastegate valve 1 will open, and a portion of the exhaust gas will leak.

Therefore, when the altitude detected by the altimeter exceeds a certain level, the three-way valve 8 is switched so that the sensing pipe 12 and the head 5 of the actuator 3 communicate with each other. Then, since the pressure in the shroud portion 10 of the impeller 19 is lower than the pressure in the compressor outlet pipe 6, the lever force of the actuator 3 becomes lower, and the boost pressure can be further increased than before switching.

Furthermore, when the altitude increases, the boost pressure can be further increased by opening the solenoid valve 18 and leaking a portion of the air through the sensing tube 12. Leak amount is orifice 17
Adjust so that the boost pressure can be set to the desired pressure.

Furthermore, the boost pressure can be further increased by opening the valve 15 and guiding a portion of the air from the branch pipe 13 through the sensing pipe 12 to the spring chamber 16 of the actuator 3.

By combining the operations of the three-way valve 8, valve 15, and solenoid valve 18 described above, the boost pressure can be finely changed in multiple stages, and smooth operation can be achieved in response to increases and decreases in altitude.

It should be noted that the turbocharger boost pressure variable device of the present invention is not limited to the above-described embodiments, and it goes without saying that various changes may be made without departing from the gist of the present invention.

[Effects of the invention] As explained above, according to the invention, the boost pressure introduction pipe and the sensing pipe taken out from the shroud of the compressor impeller are switchably connected to the actuator, and the sensing pipe is provided with an orifice and a valve. Connect the branch pipe
Furthermore, since a branch pipe equipped with a valve is connected between the sensing pipe and the spring chamber of the actuator, the control pressure to the waste gate valve actuator can be finely switched, and the boost pressure supplied to the engine can be controlled in multiple stages. This allows for various excellent effects such as being able to adapt to changes in altitude etc. with a relatively simple device without using the conventional expensive variable mechanism.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of one embodiment of the device of the present invention, and FIG. 2 is a schematic explanatory diagram of a turbocharger. 1 is a waste gate valve, 3 is an actuator, 5 is a head, 6 is a compressor outlet pipe, 7
1 is a boost pressure introduction pipe, 8 is a three-way valve, 10 is a shroud part, 11 is a guide hole, 12 is a sensing pipe, 1
3 and 14 are branch pipes, 15 is a valve, 16 is a spring chamber, 17 is an orifice, and 18 is a solenoid valve.

Claims (1)

[Scope of utility model registration request] A boost pressure introduction pipe connected to a compressor outlet pipe and a sensing pipe taken out from a shroud part of a compressor impeller are switchably connected to the diaphragm head side of an actuator that opens and closes a waste gate valve provided in a turbine chamber of a turbocharger. A variable boost pressure for a turbocharger characterized in that a branch pipe equipped with an orifice and a valve is connected to the sensing pipe, and further a branch pipe equipped with a valve is connected between the sensing pipe and the spring chamber of the actuator. Device.