JP2658337B2 - Nozzle angle adjustment device for variable capacity turbocharger - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a nozzle angle adjusting device for a variable displacement supercharger.

[Prior Art] At present, in order to improve the thermal efficiency of various prime movers, a turbocharger that turns a turbine with exhaust gas of the prime mover, drives a compressor by the turbine, and supplies air compressed by the compressor to the prime mover is known. Used.

In the above turbocharger, since the flow rate of exhaust gas used as a power source fluctuates depending on the load state of the prime mover, the angle of a blade called a nozzle for guiding the exhaust gas to the turbine wheel can be adjusted according to the load state. There is a variable displacement supercharger in which high supercharging efficiency is maintained by doing so.

A nozzle angle adjusting device of such a variable displacement supercharger will be described with reference to FIGS.

FIGS. 4 and 5 show the turbine section of the variable displacement supercharger. The casing of the turbine section is constructed by sandwiching a shroud 3 between a turbine casing 1 and a gas outlet cover 2. The nozzle shaft 4 is rotatably held by the shroud 3 via the bearing 5, the nozzle 6 is fixed to the end of the nozzle shaft 4 on the turbine casing 1 side, and the nozzle link 7 is fixed to the end of the gas outlet cover 2 on the side of the gas outlet cover 2. ing.

A donut-shaped space 9 surrounding the gas outlet 8 is formed between the gas outlet cover 2 and the shroud 3, and the nozzle link 7 and a nozzle drive ring 10 are rotatably housed in the space 9. A pin 11 and a slide joint 12 are protruded from the nozzle drive ring 10, and a slide groove 13 at the tip of the nozzle link 7 is fitted to the slide joint 12 so as to be slidable in the radial direction of the nozzle drive ring 10. I have. Further, a pin 14 and a slide joint 15 are protruded from the nozzle drive ring 10, and the slide joint 15
The slide groove 17 at the end of the drive link 16 has a nozzle drive ring
10 are slidably fitted in the radial direction, and drive link 16
The rear end of the drive shaft 19 is fixed to a drive shaft 19 that penetrates the gas outlet cover 2 via a drive bearing 18.
20 are connected. In the figure, reference numeral 21 denotes a turbine wheel, and reference numeral 22 denotes a guide for guiding the rotation of the nozzle drive ring 10.

If the drive lever 20 is driven from an external drive source, the drive shaft
19. The nozzle drive ring 10 rotates via the drive link 16, and the rotation of the nozzle drive ring 10 causes the nozzles 6 to simultaneously change the angle via the nozzle link 7 by an angle corresponding to the amount of rotation of the nozzle drive ring 10. I do.

[Problems to be Solved by the Invention] However, in the conventional nozzle angle adjusting device of the variable displacement supercharger, the nozzle angle adjusting device itself has a high temperature of 450 ° C. or more (around 500 ° C.) and performs lubrication by the high temperature. In particular, since it is provided in the turbine section where lubricating oil cannot be produced (since the lubricating oil is carbonized due to high temperature), in particular, the slide joint 12 of the nozzle drive ring 10 and the slide grooves 13 and 17 of the nozzle link 7 and the drive link 16 are formed. Therefore, the nozzle driving ring 10, that is, the radial sliding portion of the turbine wheel 21 is easily affected by high-temperature oxidation and sliding wear at the same time, and as a result, a brittle oxide layer is formed on the surface of the sliding portion by high-temperature oxidation, The oxidized layer is scraped off by sliding wear to form a new surface, and an oxide layer is formed on the newly formed surface by high-temperature oxidation, and the oxidized layer is scraped off by sliding wear. On the contrary, there is a problem that the above-mentioned sliding portion is damaged, and it is difficult to secure the reliability because the durability is lowered.

In view of the above-described circumstances, the present invention has a variable structure in which the sliding portion in the radial direction of the turbine wheel is eliminated, thereby making the structure less susceptible to high-temperature oxidation and sliding wear, thereby improving durability and reliability. It is an object of the present invention to provide a nozzle angle adjusting device for a displacement type supercharger.

Means for Solving the Problems According to the present invention, in a nozzle angle adjusting device of a variable displacement supercharger capable of adjusting the angle of a plurality of nozzles for guiding exhaust gas to a turbine wheel, one end is provided for each nozzle. A connection for connecting a fixed nozzle shaft, a link plate fixed to the other end of the nozzle shaft, and positions equidistant from the nozzle shaft between adjacent link plates with a length equal to the distance between the nozzle shafts. Plate and a drive lever for changing the angle of the nozzle, at least one of the adjacent link plates.
The present invention relates to a variable-capacity supercharger nozzle angle adjusting device, characterized in that an unconnected portion that does not connect a coupling plate is formed at a position, and a driving lever is connected to a nozzle located at the most upstream of the flow of exhaust gas. Can be provided.

[Operation] When the link plate is swung, the angle of the nozzle is changed via the nozzle shaft, and at the same time, the swing is sequentially transmitted to the adjacent link plate via the coupling plate, so that all the nozzles are simultaneously adjusted in angle. . At this time, since the link plate can be moved in the radial direction of the turbine wheel, it is not necessary to form a sliding portion in the radial direction, and each part can be connected only by the pin joint.

Further, by forming an unconnected portion at at least one location between adjacent link plates, the influence of dimensional tolerances of the link plates and the coupling plates and the effects of thermal expansion are absorbed.

Further, by providing a drive lever for the nozzle located at the most upstream of the flow of the exhaust gas, the angle of the nozzle can be adjusted without being affected by the pulsation of the exhaust gas.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and the structure of a variable displacement supercharger itself will be described as being similar to that shown in FIG.

At the other end of the nozzle shaft 4 having the nozzle 6 fixed at one end, an apex corner of an isosceles triangular link plate 23 (which may be T-shaped or Y-shaped) having, for example, three pivot points is fixed, and is adjacent to the link plate 23. The distance between one bottom corner and the other bottom corner located at the same distance a from the top corner between the link plates 23 fixed to the nozzle shaft 4 that is fixed to the adjacent nozzle shaft 4 Are connected by the connecting pin 31 and the connecting plate 24 so as to have a length equal to the distance b between the two axes to form a parallelogram link structure.

At this time, for example, it is attached to the other end of the link plate 23 'attached to the nozzle 6' located at the most upstream of the flow of the exhaust gas near the turbine inlet 25 of the turbine casing 1, and to the nozzle 6 "located at the most downstream. An unconnected portion 26 to which the connecting plate is not connected is formed between one ends of the link plate 23 ″.

Further, a link plate 2 attached to a nozzle 6 'located closest to the turbine inlet 25 and located at the most upstream position of the exhaust gas flow.
A drive lever 27 projecting to the outside is fixed to 3 ', and a drive device such as an air cylinder is attached to the end of the drive lever 27 projecting to the outside.
Connect 28.

 Next, the operation will be described.

When the drive lever 27 swings due to expansion and contraction of the drive device 28,
The link plate 23 'fixed to the drive lever 27 swings, and the angle of the nozzle 6' changes via the nozzle shaft 4.

At the same time, the swing of the link plate 23 'is sequentially transmitted to each of the link plates 23, 23 "on the downstream side of the flow of the exhaust gas via the coupling plate 24, and the swing of the link plates 23, 23" causes the nozzle shaft 4 to move. The angle of the nozzle 6, 6 ″ changes through the nozzle.

Therefore, the angles of the nozzles 6, 6 ', 6 "can be simultaneously adjusted by the drive lever 27.

At this time, the space between the link plates 23 at the adjacent positions is
Are connected so as to form a parallelogram link, so that when the link plate 23 is swung, the coupling plate 24 can move in the radial direction of the turbine wheel, so that the link plate 23
It is not necessary to mount the coupling plate 24 so as to be slidable in the radial direction of the turbine wheel, and all the pivoting portions can be configured as pin joints and only rotationally oscillated. There is no sliding part that is damaged by simultaneous influence of dynamic wear, and the durability is improved and the reliability of operation is greatly improved.

An unconnected portion that is not connected by the connecting plate 24 between the most upstream link plate 23 'and the most downstream link plate 23 "of the exhaust gas flow.
By forming the link 26, the dimensional tolerance and thermal expansion of the link plate 23 and the connecting plate 24 can be absorbed. Therefore, the distance b between the connecting pins 31 can be reduced to make the connecting plate 24, the link plate 23 and the nozzle 6 Can be increased, and these smooth operations can be obtained.

Furthermore, since the unconnected portion 26 is formed, the link plate 23
The driving force transmitted becomes weaker as the position moves away from the position of the drive lever 27.However, since the drive lever 27 is fixed to the link plate 23 'located at the most upstream of the exhaust gas flow, the pulsation of the exhaust gas The nozzle 6 ', which is most susceptible to the above, can be driven with a strong force, and the angle can be reliably adjusted.

FIG. 2 shows another embodiment of the present invention, in which the drive lever 27 'is directly fixed to the nozzle shaft 4 of the link plate 23' in a configuration substantially similar to that of FIG. The operation and effect of the present invention can be obtained.

FIG. 3 shows another embodiment of the present invention. In a configuration substantially similar to that of FIG. 1, the tip of a drive lever 27 "is pivotally attached to a turbine casing (not shown) using a pin 29, and a link plate 2 is provided.
The position of the distance c from the nozzle shaft 4 of 3 'and the position of the distance c from the pin 29 of the drive lever 27 "are connected by a connecting plate 30 so as to be equal to the distance d between the nozzle shaft 4 and the pin 29. 1 can obtain the same effects as those of FIG.

It should be noted that the nozzle angle adjusting device of the variable displacement supercharger of the present invention is not limited to the above-described embodiment, and the shape of the link plate and the coupling plate does not matter, and the method of attaching the drive lever does not matter. It is needless to say that there is nothing, the position where the unconnected portion is formed is arbitrary, and other various changes can be made without departing from the scope of the present invention.

[Effects of the Invention] As described above, according to the nozzle angle adjusting device for a variable displacement supercharger of the present invention, the following various excellent effects can be obtained.

Since the link plates fixed to the nozzle shaft are separately fixed by the coupling plate, the coupling plate can move in the radial direction of the turbine wheel when the link plate is swung, and Sliding parts can be eliminated, and each part can be made only of a pin joint. Therefore, there is no part that is damaged by simultaneous high-temperature oxidation and sliding wear, and durability and reliability can be improved.

Since at least one unconnected portion is formed between adjacent link plates, it is possible to absorb the effects of dimensional tolerances and thermal expansion of the link plate, the coupling plate, and the like.

Since the drive lever is provided for the nozzle located at the most upstream of the flow of the exhaust gas, the angle of the nozzle can be accurately adjusted without being affected by the pulsation of the exhaust gas.

[Brief description of the drawings]

1 is an overall view of one embodiment of the present invention, FIG. 2 is an overall view of another embodiment of the present invention, FIG. 3 is an overall view of another embodiment of the present invention, and FIG. 5 is a sectional view taken along the line VV of FIG. 4. In the figure, 4 is a nozzle shaft, 6, 6 ', 6 "are nozzles, 21 is a turbine wheel, 23, 23', 23" are link plates, 24 is a coupling plate, 26 is an unconnected portion, 27, 27 ' , 27 ″ indicate a drive lever, and a and b indicate distances.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-198306 (JP, A) JP-A-58-93902 (JP, A) JP-A-64-35099 (JP, A) 151940 (JP, U) Japanese Utility Model Showa 50-131004 (JP, U) Japanese Utility Model Showa 61-187974 (JP, U) Japanese Utility Model Showa 59-64434 (JP, U) Japanese Utility Model Showa 44-27765 (JP, Y1) U.S. Patent 3056541 (US, A)

Claims (2)

(57) [Claims] 1. A nozzle angle adjusting device for a variable displacement supercharger, wherein an angle of a plurality of nozzles for guiding exhaust gas to a turbine wheel is adjustable, a nozzle shaft having one end fixed to each nozzle. A link plate fixed to the other end of the nozzle shaft, a coupling plate that connects positions equidistant from the nozzle shaft between the adjacent link plates with a length equal to the inter-axis distance of the nozzle shaft, and an angle of the nozzle. A nozzle angle adjusting device for a variable displacement turbocharger, comprising: an unconnected portion that does not connect the connecting plate to at least one of the adjacent link plates, the driving angle being constituted by a driving lever that is changed. 2. A nozzle angle adjusting device for a variable displacement turbocharger according to claim 1, wherein the drive lever is provided for a nozzle located at the most upstream position of the flow of the exhaust gas.