JPH0415953Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a supercharger with a variable nozzle, and particularly to a supercharger with a variable nozzle that prevents exhaust gas from leaking from a shaft portion of a nozzle vane.

[Conventional technology]

The structure of a supercharger with a variable nozzle has been known for a long time (for example, Japanese Utility Model Application Publication No. 57-76235 and Japanese Utility Model Application Publication No. 59-5724). In the conventional structure, the variable nozzle is inserted into a bush provided in the housing, and a clearance is formed between the bush and the shaft of the variable nozzle to prevent sticking.
The variable nozzle is rotatable relative to the bush. Therefore, there was a problem in that the exhaust gas inside the turbine housing leaked to the outside through this clearance.

The basic method of suppressing exhaust gas leakage is to reduce the clearance, but if the clearance is too small, there is a risk of seizure.
In order to solve this problem, a gas leakage prevention mechanism has been proposed in which a spherical surface is provided at the contact area between the nozzle vane root of the nozzle shaft and the back plate through which the root passes (Utility Model Application No. 58-114842). Public bulletin). Also known is a method of sealing exhaust gas leaks using high-pressure air.

[Problem that the invention attempts to solve]

However, the structure of the above-mentioned Utility Model Application Publication No. 58-114842 has a problem in that the friction at the contact portion increases, resulting in poor reliability and durability. Furthermore, the sealing method using high-pressure air has the disadvantage that air from the compressor outlet is used, resulting in a large energy loss.

Generally, a piston ring is used for the high temperature seal. It is thought that if a piston ring is provided on the outer periphery of the shaft of the nozzle vane instead of the above-mentioned sealing means, it will be possible to significantly suppress gas leakage. However, when installing a conventional piston ring, in the structure in which a square groove is formed on the shaft of the nozzle vane and the piston ring is fitted into it, the diameter of the nozzle vane shaft is larger than the inner diameter of the piston ring. Otherwise, it cannot be installed. Therefore, if an elastic ring is manufactured to match the diameter of the shaft, the width and thickness of the piston ring will become extremely thin, and the contact area with the bushing will become small, leading to the problem that a sufficient sealing effect cannot be achieved. be done. Further, when the thickness and width of the piston ring are increased, the piston ring is forced to expand when it is inserted into the shaft, which causes the problem of deformation of the piston ring.

In order to improve the above-mentioned problems, the present invention has a structure that allows assembly without deforming the elastic ring (a ring corresponding to the above-mentioned piston ring), and improves the sealing performance of the shaft support part to improve the nozzle vane. An object of the present invention is to provide a supercharger with a variable nozzle that can suppress exhaust gas leakage from a clearance between a shaft and a bush to a very small amount.

[Means for Solving the Problems] According to the present invention, this object is achieved by the following supercharger with a variable nozzle. That is, a bush is provided in the housing, a shaft is inserted into the bush, a nozzle vane is provided at one end of the shaft, and the shaft is rotated by a link member connected to the other end of the shaft, thereby rotating the nozzle vane. In the supercharger with a variable nozzle, the shaft is provided with a large diameter part, a medium diameter part, and a small diameter part in order in a direction away from the nozzle vane, and the shaft is connected to the link member at the small diameter part, is located at the end of the bush on the center housing side, and an elastic ring that is pressed against the inner surface of the bush is arranged on the outer periphery of the medium diameter part, and the elastic ring is arranged in different directions in the shaft axial direction. A supercharger with a variable nozzle, characterized in that the supercharger is sandwiched between two members, the large diameter portion and the link member.

[Effect]

In a supercharger with a variable nozzle configured as described above, the elastic ring is held between the large diameter portion and the link member, which are separate members, from both sides in the axial direction of the shaft, so it is possible to spread the elastic ring around the outer periphery of the middle diameter portion of the shaft. It can be attached to the outer periphery of the shaft by inserting it from the small-diameter side, applying it to the stepped side of the large-diameter part, and holding it down with a link member from the other side. That is, the elastic ring is attached to the outer periphery of the shaft without expanding the diameter of the elastic ring. Therefore, the elastic ring is prevented from being damaged or broken. Therefore, it is possible to use a metal ring having a larger width and thickness than a normal piston ring.

When the elastic ring is installed on the shaft, it is pressed against the inner circumferential surface of the bush by self-elastic expansion, but because the elastic ring is wide,
Gas leakage between the elastic ring and the bushing is significantly reduced. Further, gas leakage between the elastic ring and the shaft is suppressed by pushing the elastic ring axially against one of the different members sandwiching the elastic ring due to the gas pressure difference. As a result, gas leakage between the bush and the shaft can be suppressed to a much smaller amount than when a conventional piston ring is used due to the elastic ring having a large width and thickness.

In addition, since the elastic ring is arranged on the outer periphery of the middle diameter part at the end of the bush on the center housing side, it is away from the nozzle vane and is relatively low temperature, so high temperatures reduce the spring effect of the elastic ring. is prevented.

〔Example〕

Preferred embodiments of the variable nozzle supercharger according to the present invention will be described below with reference to the drawings.

First Embodiment FIGS. 1 and 2 show the vicinity of a variable nozzle vane support portion of a supercharger with a variable nozzle according to a first embodiment of the present invention. In the figure, 1 indicates a turbine housing, and 2 indicates a center housing. The turbine housing 1 and the center housing 2 are fastened together by a V band 3 at the outer periphery of the contact portion. A back plate 4 forming a wall of the turbine housing 1 on the center housing 2 side is provided between the turbine housing 1 and the center housing 2.

A plurality of nozzle vanes 5 for adjusting the inflow speed of exhaust gas are provided between the turbine housing 1 and the back plate 4 so as to be rotatable with respect to the back plate 4 and the center housing 1 together with the shaft 5a. The shaft 5a of the nozzle vane 5 extends from the back plate 4 side toward the center housing 2 side.
penetrates through the air, with one end exposed to the atmosphere. The center housing 2 has a hole 2a, and the back plate 4 has a hole 2a.
A hole 4a is provided in the hole 2a, and the hole 2a and the hole 4a are formed coaxially. Center housing 2
In the hole 2a of the nozzle vane 5 and the hole 4a of the back plate 4, there is a bush 6 that supports the shaft 5a of the nozzle vane 5.
Both ends of are fitted.

The bush 6 has the shaft 5 of the nozzle vane 5.
A hole 6a through which the variable nozzle 5 is inserted is formed in the axial direction, and the shaft 5 of the variable nozzle 5 is inserted into this hole 6a.
a is rotatably inserted. Shaft 5a
consists of a large diameter portion 5b, a medium diameter portion 5c, and a small diameter portion 5d, and is formed so that the diameter becomes smaller in order in the direction away from the nozzle vane 5.

The outer circumferential surface of the large diameter portion 5b faces the inner circumferential surface of the bush 6, and there is a space between the outer circumferential surface of the large diameter portion 5b and the inner circumferential surface of the bush to smooth the movement of the variable nozzle vane 5. , a clearance is formed. The middle diameter part 5c of the shaft 5a is located at the end of the bush 6 on the center housing side, and a metal elastic ring 7 is arranged around the outer periphery of the middle diameter part 5c to suppress leakage of exhaust gas. . Medium diameter part 5c
The length in the axial direction is slightly longer than the width of the elastic ring 7, and the diameter of the middle diameter portion 5c is
It is formed smaller than the inner diameter of the elastic ring 7. The small diameter portion 5d is connected to a link member 8 that operates the nozzle vane 5. The link member 8 is swung by the rotation of the disk 12 transmitted to it by a pin that engages with a groove 13 on the outer periphery of the disk 12, which is slidably supported by a bearing 11 around the center housing 2. Link member 8
The nozzle vane 5 is rotated together with the shaft 5a around the axis of the shaft 5a by the rocking.

The elastic ring 7 is made of a metal with heat-resistant spring properties, and has a diameter of 1 in the circumferential direction like the piston ring.
It has cuts at several places, and its cross-sectional shape is rectangular. The elastic ring 7 is partially fitted into the inner peripheral surface of the bush 6 in the width direction, and the outer peripheral surface of the elastic ring 7, which tends to expand due to its own elasticity, is pressed against the inner peripheral surface of the bush 6. Both end surfaces of the elastic ring 7 in the axial direction are held between different members, that is, the step portion 5f of the large diameter portion 5b of the shaft 5a and the link member 8, and the both end surfaces of the elastic ring 7 are
The surface 5f of the stepped portion faces the surface 8a of the link member 8 in a slidable manner. A clearance equal to the difference between the width of the elastic ring 7 and the length of the medium diameter portion 5d of the shaft 5a, which is slightly longer than the width of the elastic ring 7, is formed on both ends of the elastic ring 7.

Next, the operation of the variable nozzle-equipped supercharger described above will be explained.

The elastic ring 7 is attached to the step portion 5f of the shaft 5a, which is a separate member, and the link member 8 from both sides in the shaft axial direction.
Since it is held between the surfaces 8a of the shaft 5a, it is attached to the outer periphery of the medium diameter portion 5c of the shaft 5a without expanding the diameter. That is, the elastic ring 7 is easily inserted into the bush 6 from the small diameter portion 5d side of the shaft 5a with its outer diameter slightly contracted in the radial direction.
It is located on the outer periphery of the medium diameter portion 5c of the shaft 5a.
Therefore, the elastic ring 7 is prevented from being damaged or deformed when the elastic ring 7 is attached. In addition, since there is no need to expand the diameter of the elastic ring 7, it is possible to increase the width of the elastic ring 7 without being restricted by the diameter, and the contact area between the inner surface of the bush 6 and the elastic ring 7 is expanded, resulting in a seal. The effect is greatly improved.

In addition, since the elastic ring 7 is arranged at the end of the bush 6 on the center housing side and is away from the nozzle vane, the thermal load applied to the elastic ring 7 is small, and the elastic ring 7 that occurs when the thermal load is large The spring effect of the ring 7 is prevented from deteriorating, and the sealing performance is prevented from deteriorating due to the deterioration of the spring effect.

Although there is a slight clearance on both sides of the elastic ring 7 in the axial direction, the elastic ring 7 is pushed in the axial direction by the pressure of the exhaust gas on the turbine housing 1 side. The surface 8a of the link member 8 is brought into close contact with the surface 8a of the link member 8. As a result, the gas sealing properties of the clamping portion of the elastic ring 7 are also significantly improved.

Therefore, the amount of exhaust gas leakage can be significantly reduced compared to when a conventional piston ring mounting structure is applied.

Second Embodiment FIG. 3 shows a nozzle vane of a supercharger with a variable nozzle according to a second embodiment of the present invention. The second embodiment differs from the first embodiment in that the large diameter part and the middle diameter part are made of a different member from the shaft.
Since the other configurations are similar to the first embodiment, similar parts are given the same reference numerals as those in the first embodiment, and explanations of the similar parts are omitted and only different parts will be explained. In FIG. 3, 5a indicates the shaft of the nozzle vane 5. A small diameter portion 5d is formed on the outer periphery of the shaft 5a.
extends from the link member 8 to near the end of the bush 6 on the turbine housing 1 side. Small diameter part 5
The end portion d on the center housing 2 side is connected to the link member 8. The stepped tube 10 is inserted through the small diameter portion 5d. A stepped portion is formed at the end of the tube 10 on the center housing 2 side, and the outer periphery of the stepped portion constitutes a medium diameter portion 5c. An elastic ring 7 is arranged on the outer periphery of this medium diameter portion 5c, and a part of the width of this elastic ring 7 is formed by a bush 6.
It is inserted inside. Further, the portion of the tube 10 other than the stepped portion constitutes a large diameter portion 5b. The elastic ring 7 is held between the side surface of the large diameter portion 5b and the side surface 8a of the link member 8. Further, a shaft 5a is provided at the end of the tube 10 on the turbine housing 1 side.
Another elastic ring 7 is fitted around the outer periphery.

In the variable nozzle supercharger configured as described above, two elastic rings 7 are attached to the shaft 5a of each nozzle vane 5, and exhaust gas leakage is suppressed at these two locations. That is, the elastic ring 7 on the turbine housing 1 side is pressed against the end surface of the tube 10 by the exhaust gas pressure in the turbine housing 1, and the elastic ring 7 on the center housing 2 side is pressed against the end surface of the tube 10 by the exhaust gas pressure inside the turbine housing 1, and the elastic ring 7 on the center housing 2 side is pressed against the end surface of the tube 10 by the exhaust gas pressure inside the turbine housing 1. The elastic ring 7 is pressed against the surface 8a of the link member 8 by the pressure of the exhaust gas, and the end surface of the elastic ring 7 is brought into close contact with each member. Therefore, gas leakage from the clamping portion can be suppressed to a much smaller amount than when only one elastic ring 7 is used.

In addition, since the elastic ring 7 is arranged at the end of the bush 6 on the center housing side and is away from the nozzle vane, the thermal load applied to the elastic ring 7 is small, and the elastic ring 7 that occurs when the thermal load is large The spring effect of the ring 7 is prevented from deteriorating, and the sealing performance is prevented from deteriorating due to the deterioration of the spring effect. Other operations are similar to those in the first embodiment.

[Effect of idea]

According to the variable nozzle equipped supercharger of the present invention, an elastic ring that is pressed against the inner surface of the bushing is arranged on the outer periphery of the middle diameter part of the nozzle vane shaft and at the end of the bushing on the center housing side, and the elastic ring is pressed against the inner surface of the bushing. Since it is sandwiched between two axially different members, the large diameter part and the link member, it can be assembled without deforming the elastic ring, and prevents leakage of exhaust gas from the clearance between the shaft and the bush. The effect is that the amount can be suppressed to a very small amount. As a result, it is possible to help prevent pollution caused by leaked gas, and since exhaust energy acts effectively, supercharging performance can be improved. Furthermore, it is possible to prevent heat damage in the engine room caused by high-temperature gas.

Further, since gas leakage is suppressed by the elastic ring, sufficient clearance can be obtained between the shaft of the nozzle vane and the bushing, and seizing of the shaft and bushing can be prevented. As a result, the reliability of the variable nozzle mechanism is improved, the driving force of the variable nozzle vane can be reduced, and the actuator as a driving source can be downsized.

In addition, a large diameter part, a medium diameter part, and a small diameter part are provided in order in the direction away from the nozzle vane, and an elastic ring is attached to the outer periphery of the middle diameter part and the end of the bushing on the center housing side. is away from the nozzle vane, which reduces the thermal load, prevents the spring effect from decreasing due to heat on the elastic ring, and prevents deterioration of sealing performance due to a decrease in the spring effect.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the vicinity of the nozzle vane support portion of a supercharger with a variable nozzle according to a first embodiment of the present invention;
Figure 2 is a vertical cross-section of a supercharger with a variable nozzle to which the devices shown in Figures 1 and 3 are applied, and Figure 3 is a diagram showing the second configuration of the present invention.
FIG. 3 is a longitudinal sectional view of a nozzle vane support portion of a supercharger with a variable nozzle according to an embodiment. DESCRIPTION OF SYMBOLS 1...Turbine housing, 2...Center housing, 4...Back plate, 5...Nozzle vane, 5a...Nozzle vane shaft, 5d...
...Large diameter part, 5c...Medium diameter part, 5d...Small diameter part, 6
...Button, 7...Elastic ring, 8...Link member, 10...Tube.

Claims (1)

[Scope of utility model registration request] A variable variable drive system, wherein a bush is provided in the housing, a shaft is inserted into the bush, a nozzle vane is provided at one end of the shaft, and the shaft is rotated by a link member connected to the other end of the shaft to rotate the nozzle vane. In the supercharger with a nozzle, the shaft is provided with a large diameter part, a medium diameter part, and a small diameter part in order in a direction away from the nozzle vane, the shaft is connected to the link member at the small diameter part, and the medium diameter part is connected to the link member at the small diameter part. An elastic ring is located at the end of the bush on the center housing side, and is pressed against the inner surface of the bush on the outer periphery of the medium diameter portion. A supercharger with a variable nozzle, characterized in that the variable nozzle-equipped supercharger is sandwiched between the large diameter portion and the link member.