JPH0513957Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention automatically changes the connection state between the turbine and the compressor according to the boost pressure, maintains the boost pressure appropriately, and prevents damage to the turbine housing, etc. Regarding turbochargers that can prevent this.

[Conventional technology]

When the engine speed exceeds a certain level, the amount of exhaust gas increases, and the turbocharger turbine driven by the exhaust gas rotates at an extremely high speed, and is discharged from the compressor directly connected to it. As the amount of compressed air increases, the pressure becomes high, and this high-pressure compressed air is fed to the intake system of the engine. If the boost pressure becomes excessive, it will naturally damage the intake system on which the pressure acts, as well as damage the casing of the turbocharger and the like.

Therefore, a waste gate valve is provided to discharge the exhaust gas so as not to supply it to the turbine when the boost pressure exceeds a certain value. Since this wastegate valve is installed directly on the turbine housing, the thermal strain in this part becomes uneven and cracks are likely to occur in the housing.When these cracks occur, gas leaks occur and the specified boost Pressure may not be obtained, which may result in damage to vehicles equipped with engines equipped with turbochargers.

On the other hand, in order to solve the above-mentioned problems, a turbocharger, which is equipped with an electromagnetic clutch in the middle of the shaft that directly connects the turbine and the compressor, and which is controlled according to the load condition of the engine, has been proposed, for example, in Japanese Patent Laid-Open No.
This is proposed by Publication No. 139928.

However, since the turbocharger of the invention is configured to electrically detect the boost pressure and operate the electromagnetic clutch in response to the signal, the number of devices associated with the turbocharger increases and costs increase. In addition to this, the number of failures in the electrical system increases, which in turn causes problems with the reliability of the vehicle.

In order to eliminate the drawbacks of the conventional turbocharger, the present inventor proposed a turbocharger which is provided with a clutch between the shaft of the turbine and the shaft of the compressor that is brought into contact and separated by the pressure of the compressed air obtained by the compressor. I have already proposed a charger. Although it has been confirmed that the turbocharger according to this invention works well, it does not operate the compressor proportionally depending on the amount of exhaust gas, but continuously supplies appropriately pressurized air to the engine. There was a problem that only so-called on/off operation was possible.

On the other hand, Japanese Utility Model Application No. 57-193930 discloses that a belt drive type continuously variable transmission means is provided between the compressor of the supercharging device and the drive source (crankshaft or exhaust turbine) that drives the compressor.
A supercharged engine has been proposed in which the speed ratio of the continuously variable transmission means is changed by a diaphragm-type pressure control device that introduces the pressure of the intake passage.

However, since this device has a structure in which a V-belt is wound between the compressor pulley and the drive pulley, a large space must be secured in the engine room to install this continuously variable transmission means. However, as a result, there was a problem in that the size and weight of the vehicle increased.

On the other hand, if you try to downsize this stepless transmission means, you have to make the compressor pulley and the drive pulley smaller.Furthermore, as a characteristic of the belt drive type, the compressor pulley is constantly driven by a V-belt. Since the compressor continues to receive driving force and cannot stop the rotation of the compressor,
As a result, the gear ratio width could not be set sufficiently large, and the degree of freedom in boost pressure control was low.

[Purpose of invention]

In view of the above problems, the present invention does not require the use of electrically operated sensors or controllers, and can reduce the rotational speed of the compressor as boost pressure increases. In the event of an abnormal rise, the rotation of the compressor can be completely stopped to reliably prevent further increase in boost pressure.Moreover, the turbocharger is small and has an extremely high degree of freedom in boost pressure control. The purpose is to provide

[Summary of the idea]

In order to achieve the above object, the turbocharger of the present invention includes a fluid clutch between the rotating shaft of the turbine and the rotating shaft of the compressor, and an impeller connected to the rotating shaft of the turbine and an impeller connected to the rotating shaft of the turbine. An impeller connected to the rotating shaft of the compressor is provided, and a plurality of variable blades capable of cutting off torque transmission between these impellers are rotatably provided to adjust the pressure of the air sent out from the compressor. Therefore, the configuration is characterized in that a diaphragm device is provided for changing the rotation angle of the variable blade so as to reduce the torque transmission rate of the fluid clutch as the pressure increases.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Figure 1 is a cross-sectional view of the turbocharger, where the turbine T and compressor C are connected to the shaft 1A of the turbine T.
and the shaft 1B of the compressor C are connected via a fluid clutch 2. An impeller 3 is fixed to one end of the shaft 1A of the turbine T, and is rotatably housed in a housing 4. On the other hand, an impeller 5 is provided at one end of the shaft 1B of the compressor C, and is rotatably housed in a housing 6.

Exhaust gas G from the engine is supplied into the housing 4 of the turbine T, drives the impeller 3, and then is discharged from the discharge port 7. On the other hand, air A that has been purified by an air cleaner (not shown) is supplied from the supply port 8 of the compressor C, is pressurized by the rotation of the impeller 5, is discharged from the discharge port (not shown), and is supplied to the engine. Ru.

Shaft 1A of turbine T and shaft 1B of compressor C
is supported by a bearing 9 provided in the intermediate casing 10. In addition, the intermediate casing 10
The lubricating oil O is supplied from a supply port 11 to cool parts such as the bearing 9.

The control lever 12 of the fluid clutch 2 provided between the shafts 1A and 1B is connected to a diaphragm device 13.
The hydraulic clutch 2 is connected to a diaphragm 14 by a lever 15, and is configured to actuate the control lever 12 by applying a boost pressure B to the diaphragm device 13 to adjust the coupling force of the fluid clutch 2.

As shown in FIG.
The end of shaft 1B of is inserted, and these shafts 1A, 1
A driving-side impeller 21 and a driven-side impeller 22 are provided at B, respectively. As shown in FIG. 3, four variable blades 23A, 23 are installed at positions avoiding the rotation range of these impellers 21, 22.
B, 23C, and 23D are provided.

These variable blades 23A, 23B, 23
C, 23D has the function of a kind of valve body or guide vane, and is a blade formed in a substantially fan shape, and a plurality of blades (for example, four blades) are gathered toward the center from the side wall of the casing 20. It is rotatably supported by a shaft 24 fixed to the casing 20. and one variable blade 2 of the variable blades.
A control lever 12 is provided on a shaft 25 of 3A, and one end of the lever 15 is connected via a pin 12A provided at one end of this control lever 12.
The other end is connected to the diaphragm device 13.

Variable blades 23A, 23B, 23C, 23D
A bevel gear 27 is attached to each gathered portion of the tip of the
A bevel gear 27 is provided at the tip of the shaft 1B.
When the variable blade 23A is driven via the bevel gear 27A, the other variable blades 23B, 23C, and 23D also rotate in the same direction. Incidentally, a shaft 28 is provided at the tip of one of the variable blades 23B and 23D, and a bearing is provided on the other shaft facing the variable blades 23B and 23D. ing.

As mentioned above, the variable blades 23A, 23B, 23
For example, if the variable blade 23A rotates to the right, the other variable blades 23B, 23C, 2
3D also rotates in the same direction all at once to adjust the opening state of the central portion of the casing 20.

When the variable blade 23A is rotated by the control lever 12, the variable blade 23B is rotated in the direction of arrow r via the bevel gear 27 provided on the variable blade 23A and the bevel gear 27A, as shown in FIG. do. Therefore, when the variable blade 23A rotates in the R direction due to the rotation of the control lever 12, the other variable blades 23B, 23C, and 23D also rotate in the r direction.

Figure 3 shows variable blades 23A, 23B, 23C, 2 when boost pressure B exceeds a predetermined pressure.
This shows a 3D state in which these blades rotate simultaneously in the same direction and close across the space between impellers 21 and 22.

In this state, the impeller 21 provided on the shaft 1A of the turbine T rotates at high speed, causing the casing 2
Even if the hydraulic oil sealed in the casing 20 is sent out, the variable blades 23A, 23B, 23C, and 23D divide the inside of the casing 20 into two, so the hydraulic oil will not flow to the impeller 22 side on the compressor C side at all. , or it will decrease significantly, compressor C will not operate and compressed air A will not be delivered.

As the engine exhaust gas G increases, the turbine T
The rotational speed of compressor A increases, and compressed air A is discharged from compressor C driven via fluid clutch 2.
The pressure, that is, the boost pressure B, gradually increases, but since the boost pressure B is supplied to the diaphragm device 13, the diaphragm 14 is displaced, and the control lever 12 is rotated via the lever 15, as described above. Variable blades 23A, 23
Rotate B, 23C, and 23D in the same direction all at once.

The variable blades 23A, 23B, 23C, 2
The amount of hydraulic oil flowing from the impeller 21 on the turbine T side (impeller on the driving side) to the impeller 22 on the compressor C side (impeller on the driven side) changes continuously due to the valve action accompanying the rotation of the 3D. The transmission of power to the sides changes.

These variable blades 23A, 23B, 23
The rotating state of C and 23D is such that when the engine speed exceeds a certain value, the center of the casing 20 is closed as shown in Figure 3, and the hydraulic oil sent out from the impeller 21 moves to the impeller 22 side on the compressor C side. The situation is such that it does not occur.

In a range where the engine speed is low, the variable blades are rotated as shown in FIG. 2 (from the state shown in FIG. 3 to perpendicular to the plane of the paper) to minimize the resistance at the center of the casing 20, thereby reducing the fluid flow. Clutch 2 is now fully engaged. When the engine output gradually increases, the variable blades 23A, 23B, 23C, and 23D are rotated as described above to make it difficult for the hydraulic oil to flow, thereby reducing the driving force of the compressor C.

Note that while the engine is rotating, the impeller 21 (turbine rotor) rotates and stirs the hydraulic oil.
Although stirring resistance occurs, overrun of the impeller 21 can be prevented by setting this stirring resistance to a certain value. Also, impeller 21
As the casing 2 rotates, the temperature of the hydraulic oil increases and its viscosity decreases, which affects power transmission.
It is preferable to provide cooling fins on the outside of the cylinder 0 to cool the hydraulic oil.

[Effect of idea]

In the turbocharger of the present invention, a fluid clutch is provided between a rotating shaft of a turbine and a rotating shaft of a compressor, and within this fluid clutch, an impeller connected to the rotating shaft of the turbine and a rotating shaft of the compressor are connected. A plurality of rotatable variable blades capable of cutting off torque transmission between these impellers are provided, and the pressure is increased by the pressure of the air sent out from the compressor. The present invention is characterized in that a diaphragm device is provided that changes the rotation angle of the variable blade so as to reduce the torque transmission rate of the fluid clutch as the variable blade changes, so that the following effects can be achieved.

A diaphragm device that operates in response to boost pressure can rotate the variable blades of the fluid clutch, which not only changes the rotational speed of the compressor, but also changes the speed of the impeller in the fluid clutch, which is connected to the rotating shaft of the turbine. By using variable blades to isolate the impeller in the fluid clutch connected to the rotating shaft of the compressor,
The rotation of the compressor can be stopped, and the degree of freedom in boost pressure control can be extremely increased.

In addition, to transmit the driving force of the fluid clutch, which is a transmission mechanism, we do not use belts or chains, but instead use a fluid clutch with a transmission function in which the impeller on the driving side and the impeller on the driven side face each other closely. As a result, its external dimensions can be made extremely small in terms of structure, and it can fit into the small space between the turbine housing and compressor housing of the turbocharger, allowing for extremely high boost pressure control freedom as described above. Although the present invention has high efficiency, it is possible to prevent an increase in the size and weight of the vehicle.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the main parts of a turbocharger according to an embodiment of the present invention, Fig. 2 is a cross-sectional view of the fluid clutch taken along the turbine shaft, and Fig. 3 is a cross-sectional view showing the fluid clutch along the turbine shaft. FIG. 3 is a cross-sectional view taken orthogonally. T...Turbine, C...Compressor, 1A...
...Turbine shaft, 1B...Compressor shaft, 2
... Fluid clutch, 10 ... Intermediate casing, 1
2... control lever, 13... diaphragm device,
14...Diaphragm, 15...Lever, 20...
...Casing, 21, 22... Impeller, 23
A, 23B, 23C, 23D...variable blade,
24...shaft, 27...bevel gear, 28...shaft.

Claims (1)

[Scope of utility model registration request] A fluid clutch is provided between the rotating shaft of the turbine and the rotating shaft of the compressor, and within this fluid clutch,
An impeller connected to the rotating shaft of the turbine and an impeller connected to the rotating shaft of the compressor are provided, and a plurality of variable blades capable of cutting off torque transmission between these impellers are rotatably provided. , a diaphragm device is provided for changing the rotation angle of the variable blade so as to reduce the torque transmission rate of the fluid clutch as the pressure of the air delivered from the compressor increases. Features a turbo charger.