JPH034721Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a turbocharger (exhaust supercharger) with a variable displacement turbine.

[Conventional technology]

Conventionally, an exhaust supercharger is often used as a means for increasing the output per cylinder volume of an internal combustion engine.

This exhaust supercharger uses a turbine to receive high-temperature, high-pressure exhaust gas supplied from the exhaust manifold of an internal combustion engine, and supercharges each cylinder via the intake manifold by driving a blower that is directly connected to the turbine.

Generally, an exhaust supercharger attached to an internal combustion engine is designed to correspond to the set operating range of the internal combustion engine and to exhibit a predetermined supercharging effect, but in this case,
When the internal combustion engine approaches the lower limit of its set operating range,
The supercharging effect of an exhaust supercharger often decreases.

In order to increase the supercharging effect in such low-speed operating ranges and increase the low-speed torque of the internal combustion engine, an exhaust supercharger with a variable capacity turbine (hereinafter referred to as an exhaust supercharger or turbocharger) is used. .

For example, in the exhaust supercharger 1 shown in FIG. 5 having such a function, a plurality of nozzle vanes 4 are arranged in an annular row in an annular inlet 3 around the turbine wheel 2.

When the amount of exhaust gas flowing into the annular inlet 3 is large, each nozzle vane 4 is spaced apart from other adjacent nozzle vanes and supported so as not to create a large resistance to the exhaust gas.

On the other hand, when the amount of exhaust gas flowing into the annular inlet 3 is small, each nozzle vane 4 is rotated to narrow the distance between them.

Thereby, even if the amount of exhaust gas flowing in is small, its velocity energy can be effectively applied to the turbine wheel 2, so that the internal combustion engine can increase low-speed torque.

Such an exhaust supercharger 1 includes, as members for operating the nozzle vanes 4, a nozzle vane shaft 6 pivoted to a back plate 9 attached to a bearing housing 5, a lever 7 fixed to the nozzle vane shaft 6, and a lever 7 fixed to the nozzle vane shaft 6. It has a rotating ring 8 connected to the rotating end side of the lever 7 and rotatably supported by the bearing housing 5.

When assembling the exhaust supercharger 1 equipped with these nozzle vane operating members, first the rotary ring 8 is fitted onto the bearing housing 5, and then the back plate 9 to which a plurality of nozzle vanes 4 are attached is attached.
is fixed to the bearing housing 5. moreover,
The lever 7 on each nozzle vane side is connected to the rotation ring 8 side, respectively.

[Problem that the invention attempts to solve]

By the way, in such an exhaust supercharger 1,
High heat from the turbine side is transferred to the connecting portion between the lever 7 and the ring 8, and the sliding portion operates under harsh conditions in the high temperature and dry atmosphere.

Under such conditions, the sliding parts wear out in a short period of time, resulting in a problem that the exhaust supercharger 1 cannot be operated stably over a long period of time.

That is, in the past, a hard plated lever was used as the lever 7, and there was a problem in that the plated layer wore out relatively quickly, revealing the base material, and then the wear progressed rapidly.

The present invention is an attempt to solve these problems, and aims to provide a variable exhaust inlet turbocharger that can stably adjust the opening of the turbine exhaust inlet over a long period of time. do.

[Means for solving problems]

Therefore, the variable exhaust inlet turbocharger of the present invention includes a bearing housing that supports a center shaft, a turbine housing attached to an axial end of the bearing housing, in a turbocharger connected to an engine.
A turbine impeller disposed within the turbine housing and attached to the end of the center shaft; a plurality of nozzle vanes arranged in a row along the circumferential direction of the annular inlet and capable of changing the opening area of the annular inlet by rotation; and one end fixed to the nozzle vane. A support shaft that is pivotally supported by the bearing housing and extends outside the bearing housing, and a rotation mechanism that is connected to the other end of the support shaft to rotate the rotation mechanism are provided. It is composed of a ring rotatably attached to the outer periphery of the bearing housing, a drive control mechanism that rotates the ring, and a lever that connects the ring and the support shaft. In order to convert the rotation of the support shaft, the lever rotates the support via a slider whose one end is fixed to one of the ring or the support shaft and the other end is pivotally connected to the other of the ring or the support shaft. The lever is connected so that it can slide from the shaft position to the pivot position of the slider, and the lever is made of a martensitic structure in which chromium carbide is precipitated, in order to prevent wear caused by sliding between the slider and the lever. The slider is made of heat-resistant steel, and the slider is made of ceramics.

[Effect]

With the above-mentioned configuration, during operation, the turbine side opening of the exhaust supercharger is stably and smoothly adjusted over a long period of time so that the capacity corresponds to the engine operating condition, and a good supercharging effect is achieved. Stably obtained over a long period of time.

〔Example〕

Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. Figures 1 to 4 show a variable exhaust inlet turbocharger as an embodiment of the present invention.
Fig. 1 is a schematic diagram of the main part of the lever, Fig. 2 is a vertical cross-sectional view thereof, Fig. 3 is a cross-sectional view taken along the - arrow in Fig. 2,
FIG. 4 is a sectional view taken along the - arrow in FIG. 2.

As shown in FIGS. 1 to 4, the exhaust supercharger 10 is
An outer frame is formed by a central bearing housing 11 and a blower housing 12 and a turbine housing 13 that are respectively attached to both ends of the bearing housing in the axial direction.
The bearing housing 11 pivotally supports a center shaft 15 through a floating metal 14 approximately at its center.

The center shaft 15 has a blower fan wheel 16 and a turbine wheel 17 attached to its left and right ends.

An oil passage 19 for supplying oil to the floating metal 14 is formed in a bearing support portion 18 in the bearing housing 11 that supports the floating metal 14. Note that the reference numeral 20 indicates an oil discharge port.

The bearing housing 11 and the turbine housing 13 are fastened and fixed by an annular connecting belt 21. A turbine wheel 17 is housed between the two, and a turbine housing 1 facing the outer circumference of the turbine wheel 17 is provided.
3 has an annular inlet 22 formed therein.

High-temperature, high-pressure exhaust gas is supplied to this annular inlet 22 from the exhaust manifold side of the engine (not shown).
The turbine wheel 1 receives the velocity energy of this exhaust gas.
7 is set to rotate.

On the right end side of the bearing housing 11, a plurality of nozzle vanes 24 are pivotally attached to a wall portion 23 at the position of the annular inlet 22.

As shown in FIG. 3, a plurality of nozzle vanes 2
4 are arranged along the circumferential direction of the annular inlet 22, and are arranged so that their axial directions coincide with the axial direction of the turbine.

Further, each nozzle vane 24 has a wall portion 23
(See FIG. 2) is fixed to one end of a support shaft 25 that extends through and is pivotally supported. Each nozzle vane 2
4, by rotating the support shaft 25, the distance t between the adjacent nozzle vanes 24 is changed;
Thereby, the opening amount of the annular inlet 22 can be changed.

Each support shaft 25 is pivotally attached to the wall via a sleeve 26, and a lever 27 is attached to the other end.

Note that the sleeve 26 may be securely fixed to the bearing housing 11 by a holding plate 32, or the nozzle vane 24 and the turbine housing 13 may be securely fixed to the bearing housing 11.
In order to reduce the accumulation tolerance of the axial clearance between the sleeve 26 and the holding plate 32, a slight gap may be provided between the sleeve 26 and the holding plate 32, so that the holding plate 32 and the bearing housing 11 are in close contact with each other.

The levers 27 are attached to each support shaft 25 and arranged radially around the center shaft 15, and each lever 27 is connected to the ring 31 at its rotation end.

This ring 31 has a pair of ring supports 2
8 is installed.

Each ring support 28 has an arcuate end 281 formed inside thereof that slides into an annular groove 30 formed in the outer circumferential wall 111 of the bearing housing 11, and an outer end 282 of the ring support 28 that is connected to the ring 31 by a bolt 38.
Fixed.

A rotating portion 29 is formed by integrally assembling the pair of ring supports 28 and the ring 31, and this rotating portion 29 is fitted onto the annular groove 30 and rotates around the center shaft 15. It has become possible to move.

Furthermore, as shown in FIG. 2, the ring 31 is attached with a pin 33 that protrudes in a direction parallel to the center shaft direction A.
3 is engaged with a U-shaped end 271 (see FIGS. 1 and 4) formed at the rotating end of each lever 27 via a slider 51.

That is, the slider 51 is pivotally connected to each of the pins 33, and is formed in the shape of a cylinder with both circumferential ends cut out.

Then, the notched side of the slider 51 is
The slider 51 and the U-shaped end 271 are engaged with the inner periphery of the U-shaped end 271 of the lever 27 so that the slider 51 and the U-shaped end 271 can slide. , the U-shaped end 271 is allowed to slide in the direction from the support shaft 25 toward the pin 33.

Furthermore, the lever 27 is made of a material with a martensitic structure in which chromium carbide is precipitated, and the slider 51 is made of ceramics.

This prevents the sliding portion 51a of the slider 51 and the sliding portion 271a of the lever 27 from being worn out.

That is, the sliding parts 51a and 271a of this embodiment
No wear-resistant member has been provided that is effective under the harsh conditions of high temperature, dry air, and only data on high temperature, dry vacuum conditions have been provided in aerospace technology.

The above combination of materials has been confirmed to have wear resistance under the above conditions as a result of various experiments, and allows the rotating portion 29 to operate stably over a long period of time.

That is, in the past, the lever 27 was hard-plated, and there was a problem in which the plating layer wore out relatively quickly and the base material appeared, and then the wear progressed rapidly. According to
The problem is solved.

The lever 27 is made of heat-resistant steel that is Fe-based, for example, the basic components are 2.3% or less C, 11 to 24% Cr, and further contains additives such as Ni, Mo, and Si. ing.

Then, after forming the powder containing the above-mentioned components into the shape of the lever 27, the powder formed into the lever shape is placed in a reduction furnace with an atmosphere of deuterium or ammonia decomposition gas at a temperature of approximately 1150°C. ℃ for about 60 minutes, and then the sintered material is cooled in air to obtain a heat-resistant steel having a chromium carbide-based martensitic structure.

Furthermore, this heat-resistant steel is used at a set temperature higher than the normal operating temperature in a turbocharger (e.g.
Heat treatment is performed for a predetermined period of time at a temperature of approximately 500 to 650°C to reduce local stress concentration and ensure sufficient hardness.

On the other hand, the ring 31 has a connecting piece 3 on its outer peripheral surface.
4 is provided protrudingly, and an actuator 35 is connected to this connecting piece 34.

By applying an output signal from a drive control mechanism (not shown) to this actuator 35,
The ring 31 of the rotating portion 29 is rotated by a predetermined amount.

In this way, ring 31, ring support 2
8, the pin 33, the lever 27, the slider 51, the support shaft 25, the connecting piece 34, and the actuator 35 constitute a rotation mechanism for the nozzle vane 24.

Incidentally, reference numeral 36 denotes a bearing surface 36 that is disposed within the annular groove 30, is press-fitted into the bottom of the annular groove 30, and is in sliding contact with the arcuate end 281 of the ring support.
1 is shown, and four ring bearings 36 are installed in the annular groove 30 to constitute a bearing for the ring support 28 in the rotating portion 29.

Annular groove 30 and arcuate end 28 of ring support 28
Molybdenum disulfide S as a solid lubricant is sealed between the inner circumference of the ring bearing 36 and the inner circumference of the arc end 281 to reduce wear resistance when the ring support 28 rotates at the sliding portion between the outer circumference of the ring bearing 36 and the inner circumference of the arc end 281. It is starting to decrease.

Further, at the arc end 281, one guide 50 is provided between each pair of ring bearings 36, 36.
is attached by press-fitting its base 50a.

As a result, the guide 50 is driven as the ring support 28 rotates, and the flat plate portion of the guide 50 moves the inner periphery of the arcuate end 281 and the ring bearing 36.
Molybdenum disulfide S can be guided and supplied between the outer periphery and the outer periphery.

Since the exhaust inlet variable turbocharger as an embodiment of the present invention is constructed as described above, the assembly work of the exhaust supercharger 10 shown in FIGS. 1 to 4 is performed as follows.

First, the bearing housing 11 is placed on a pedestal (not shown).

At this time, the bearing housing 11 has its wall portion 23 facing upward, and all of the nozzle vanes 24 are pivotally attached to this wall portion 23.

Subsequently, all the levers 27 on the nozzle vane 24 side are arranged radially with respect to the center shaft center line l.

Next, the ring support 28 is inserted into the annular groove 30, and the inner circumference of the arcuate end 281 is inserted into the ring bearing 36.
bring it into contact with.

and the outer end 282 of the ring support 28.
are assembled and integrated into the ring 31 with bolts 38. At this time, the slider 51 pivotally supported by the ring 31 is brought into engagement with the U-shaped end 271 of the lever 27.

As a result, the ring support 28 and the ring 31 are fitted into the annular groove 30, and the rotating portion 29 and the plurality of nozzle vanes 24 are connected.

Next, the center shaft 15 to which the turbine impeller 17 is attached is fitted into the bearing support part 18, and further the turbine housing 13 is stacked on the bearing housing 11, and both are fixed with the connecting belt 21.

After this, the bearing housing 11 side is reversed, and the blower fan wheel 1 is attached to the upward center shaft 15.
Insert 6 and tighten the nut.

Next, the blower housing 12 is superimposed on the bearing housing 11, and both are fixed with the connecting belt 37, and the assembly of the exhaust supercharger 10 is almost completed. Note that the center shaft 15 may be attached before the nozzle vane 24 is assembled.

Such an exhaust supercharger 10 is attached to an engine (not shown) and is driven by receiving exhaust gas. At this time, the exhaust gas flows into the turbine wheel 17 through the gap t between each nozzle vane on the annular inlet 22 side. do.

Here, if the inflow amount of exhaust gas exceeds the set amount, the blower fan wheel 16 side performs proper supercharging operation.

On the other hand, when the inflow amount of exhaust gas falls below the set amount, the rotating portion 29 is operated by a drive control mechanism (not shown), and the rotating portion 29 is rotated around the center shaft 15 by the actuator 35, and interlocks with this. Each nozzle vane 24 is rotated.

As a result, the interval t between each nozzle vane is fitted and the opening amount of the annular inlet 22 is reduced, so even if the amount of exhaust gas flowing into the annular inlet 22 is reduced, the velocity energy of the exhaust gas is maintained at a predetermined level. Can be retained.

In other words, even if the displacement is reduced to some extent during low-speed operation, by narrowing the opening amount of the annular inlet 22, the turbine wheel 17 receives enough velocity energy from the exhaust gas to obtain a supercharging effect.
This allows the low-speed torque of the internal combustion engine to be increased.

By the way, when the rotating part 29 rotates, the arc end 281 of the ring support 28 slides smoothly due to the molybdenum disulfide S supplied between the inner periphery of the arc end 281 and the outer periphery of the ring bearing 36.
The rotating portion 29 can be rotated smoothly.

That is, when the rotating part 29 rotates, the guide 50 is driven by the rotation of the ring support 28, and the guide 50 moves the molybdenum disulfide S to the arcuate end 2.
Molybdenum disulfide S is guided and supplied to the sliding part gap between the inner periphery of the ring bearing 81 and the outer periphery of the ring bearing 36, and a sufficient amount of molybdenum disulfide S is always supplied to the sliding part gap.

Further, as the rotating portion 29 operates, the sliding portion 271a of the lever 27 and the sliding portion 51a of the slider 51 slide. Since the slider 51 is made of ceramics, the sliding parts 51a and 271a are prevented from wearing out even under the harsh conditions of high temperature and dry air, and the rotating part 29 can operate for a long time. It is performed stably over a period of time.

Note that molybdenum disulfide S is applied to the surface of the ring bearing 36 in advance.

The connection between the ring 31 and the lever 27 is as follows:
Simply slider 51 and lever 27 on ring 31 side.
This is a work to engage the U-shaped end 271 by fitting, and these assembly works can be easily performed.

[Effect of idea]

As detailed above, according to the variable exhaust inlet turbocharger of the present invention, the turbocharger connected to the engine includes a bearing housing that supports the center shaft, and a turbine housing that is attached to the axial end of the bearing housing. a turbine wheel disposed within the turbine housing and attached to the end of the center shaft; and a turbine wheel facing the outer periphery of the turbine wheel within the turbine housing to allow the exhaust gas of the engine to flow into the turbine wheel. a plurality of nozzle vanes arranged in a row along the circumferential direction of the annular inlet and capable of changing the opening area of the annular inlet by rotation; and one end fixed to the nozzle vane. At the same time, a support shaft that is pivotally supported by the turbine housing and extends outside the bearing housing, and a rotation mechanism that is connected to the other end of the support shaft and rotates the rotation mechanism are provided. is composed of a ring rotatably attached to the outer periphery of the bearing housing, a drive control mechanism that rotates the ring, and a lever that connects the ring and the support shaft. In order to convert the rotation into the rotation of the spindle, the lever is moved through a slider whose one end is fixed to one of the ring or spindle and the other end is pivotally connected to the other of the ring or spindle. Connected so as to be able to slide from the position of the support shaft toward the pivot position of the slider, in order to prevent wear caused by sliding between the slider and the lever;
It has a simple configuration in which the lever is made of heat-resistant steel with a martensitic structure in which chromium carbide is precipitated, and the slider is made of ceramics, and is equipped to adjust the opening of the exhaust gas inlet on the turbine side. We are now able to sufficiently prevent wear on the sliding parts of the lever and slider, even under the harsh conditions of high temperature and dry air, allowing the exhaust turbocharger to operate stably over a long period of time. There are advantages that can be achieved.

[Brief explanation of the drawing]

Figures 1 to 4 show a variable exhaust inlet turbocharger as an embodiment of the present invention. Figure 1 is a schematic diagram of the main part of the lever, Figure 2 is a vertical cross-sectional view, and Figure 3 is a vertical sectional view of the lever. 2 is a sectional view taken along the - arrow in FIG. 2, FIG. 4 is a sectional view taken along the - arrow in FIG. 10... Exhaust supercharger (turbocharger), 11... Bearing housing, 12...
Blower housing, 13... Turbine housing, 14... Floating metal, 15... Center shaft, 16... Blower fan, 17... Turbine impeller, 18... Bearing support portion, 19... Oil passage, 20 ... Oil discharge port, 21 ... Connection belt, 22 ... Annular inlet, 23 ... Wall, 24 ...
Nozzle vane, 25... Support shaft, 26... Sleeve, 27... Lever, 28... Ring support,
29... Rotating part, 30... Annular groove, 31... Ring, 32... Holding plate, 33... Pin, 34... Connection piece, 35... Actuator, 36... Ring bearing, 37... Connection Belt, 38... Bolt, 50... Guide, 50a... Base, 51...
Slider, 51a...Sliding part, 111...Outer peripheral wall, 271...U-shaped end, 271a...Sliding part, 2
81... Arc end, 282... Outer end, 361...
Bearing surface, l... Center shaft center line, S... Molybdenum disulfide as a solid lubricant.

Claims (1)

[Scope of utility model registration request] A turbocharger connected to an engine includes a bearing housing that supports a center shaft, a turbine housing attached to an axial end of the bearing housing, and a turbine housing disposed within the turbine housing and attached to the center shaft end. a turbine wheel; and an annular inlet formed in the turbine housing to face the outer periphery of the turbine wheel in order to allow exhaust gas from the engine to flow into the turbine wheel; a plurality of nozzle vanes arranged in a row along the axis and capable of changing the opening area of the annular inlet by rotation thereof; and a support shaft having one end fixed to the nozzle vane, pivotally supported by the bearing housing, and extending outside the bearing housing. and a rotation mechanism connected to the other end of the support shaft for rotation thereof, and the rotation mechanism is connected to the ring rotatably attached to the outer periphery of the bearing housing. It is composed of a drive control mechanism that rotates the ring, and a lever that connects the ring and the support shaft.In order to convert the rotation of the ring into rotation of the support shaft, the lever rotates one end of the mechanism. The slider is fixed to one of the ring or the support shaft, and the other end is pivotally connected to the other end of the ring or the support shaft, so that the slider can slide from the position of the support shaft to the pivot position of the slider. In order to prevent wear caused by sliding between the slider and the lever, the lever is made of heat-resistant steel having a martensitic structure in which chromium carbide is precipitated, and the slider is made of ceramics. A variable exhaust inlet turbocharger.