JP3876212B2 - Surface treatment structure and surface treatment method for variable capacity supercharger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface treatment structure of components in a variable capacity supercharger in which the capacity of a turbine is variable by a variable nozzle mechanism that transmits a driving force of an actuator to a nozzle vane via a link portion and changes a blade angle of the nozzle vane. And a surface treatment method.
[0002]
[Prior art]
In an internal combustion engine with a supercharger, in order to match the exhaust gas flow rate from the engine with the gas flow rate that is the optimum operating condition of the supercharger, the exhaust gas flow rate sent to the turbine from the spiral scroll passage is used for engine operation. In recent years, variable capacity superchargers that can be changed according to the state have been widely used.
[0003]
Such variable capacity turbochargers are disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 10-26028), Patent Document 2 (Japanese Patent Laid-Open No. 2001-329850), or Patent Document 3 (Japanese Patent Laid-Open No. 11-62603). As shown, a variable nozzle mechanism is provided that transmits a driving force from an actuator such as a pneumatic type or an electric motor type to a nozzle vane via a link portion and changes the blade angle of the nozzle vane. Variable nozzle assemblies such as the nozzle vane installed at the exit of the scroll passage in the turbine casing through which high-temperature exhaust gas flows, the nozzle mount that supports the nozzle vane, and the link unit that rotationally drives the nozzle vane The turbine casing can be operated without lubrication.
[0004]
In the variable capacity supercharger, the gap between the sliding surfaces of both ends of the nozzle vane and the inner surface of the turbine casing, that is, the side clearance of the nozzle vane, reduces the amount of exhaust gas passing through the gap and avoids a decrease in turbine efficiency. Therefore, it is formed as small as possible.
Such a side clearance is formed between the sliding surfaces of both ends of the nozzle vane and the metal surface of the inner surface of the turbine casing in the prior art as shown in Patent Document 1 or Patent Document 2, so that the operation of the nozzle vane is performed smoothly. It is formed in a minimum gap.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-26028 (for example, FIG. 1)
[Patent Document 2]
JP 2001-329850 A (for example, FIG. 1 and FIG. 2)
[Patent Document 3]
JP-A-11-62603 (for example, FIG. 1)
[0006]
[Problems to be solved by the invention]
As described above, in the variable displacement supercharger disclosed in Patent Document 1, Patent Document 2, or Patent Document 3, variable nozzles such as a nozzle vane, a nozzle mount that supports the nozzle vane, and a link unit that rotationally drives the nozzle vane. The assembly is structured to operate in a non-lubricated state in a high-temperature turbine casing.
Therefore, in such a variable capacity supercharger, the sliding movement of the nozzle vane fully closed to the nozzle vane fully open to the nozzle vane fully closed is repeatedly performed in a state where the sliding portion of the variable nozzle assembly is unlubricated in a high temperature atmosphere. The initial conformability of the sliding portion is not good, and the sliding resistance during operation becomes extremely large.
[0007]
For this reason, in such a prior art, since the sliding between the nozzle vane is fully closed and fully opened under the condition that the sliding resistance of the sliding portion of the variable nozzle assembly is extremely large, the hysteresis of the operating characteristics of the nozzle vane is reduced. The turbocharger performance increases and the turbocharger performance becomes unstable, and it is easy to induce deterioration in acceleration and exhaust gas due to a primary decrease in supply pressure (supercharging pressure) during a transition period such as gear shifting.
[0008]
In the variable capacity turbocharger disclosed in Patent Document 1, Patent Document 2, or Patent Document 3, the side clearance between the sliding surfaces of both ends of the nozzle vane made of a metal surface and the inner surface of the turbine casing made of the metal surface is set in the turbine. It is formed as small as possible for the purpose of avoiding a decrease in efficiency, but the side clearance decreases due to the deformation of both the metal surfaces, and the operating resistance of the metal surface and the nozzle vane is increased or the fixing of both is taken into consideration. The side clearance must be taken to a certain extent, and gas leakage from the side clearance is a factor in reducing turbine efficiency.
And so on.
[0009]
In view of the problems of the prior art, the present invention reduces the sliding resistance of the sliding portion by improving the lubricity of the sliding portion of the variable nozzle assembly, and always keeps the side clearances on both sides of the nozzle vane properly. Accordingly, it is an object of the present invention to provide a surface treatment structure and a surface treatment method for a variable capacity turbocharger that can prevent a decrease in turbine efficiency, a decrease in acceleration performance in a transition period, and a deterioration in flue gas.
[0010]
[Means for Solving the Problems]
In order to solve such a problem, the present invention provides a first aspect of the invention in which exhaust gas flowing through a scroll passage in a turbine casing is caused to act on a turbine wheel through a nozzle vane rotatably supported by a nozzle mount. In a variable capacity turbocharger in which the capacity of a turbine is variable by a variable nozzle mechanism that rotationally drives the turbine wheel and transmits the driving force of an actuator to the nozzle vane via a link portion to change the blade angle of the nozzle vane. Further, among the members constituting the variable nozzle mechanism, carbon ultrafine powder containing carbon as a main component is melted in a solvent on the slide surfaces at both ends of the nozzle vane and the outer peripheral surface of the nozzle shaft that supports the nozzle vane on the nozzle mount. A variable capacity supercharger characterized by forming a generated carbon-based dry film To propose a surface treatment structure.
[0011]
[0012]
[0013]
[0014]
[0015]
According to this invention, the carbon-based dry film is formed on the sliding surfaces of both ends of the nozzle vane and the outer peripheral surface of the nozzle shaft that supports the nozzle vane on the nozzle mount.
[0016]
Therefore, since the forming a film of a solid lubricant consisting of both end slide surface and the carbon-based dry film carbon super fine powder produced by melting in a solvent mainly composed of carbon on the outer peripheral surface of the nozzle shaft Roh Zuruben, When the sliding member disclosed in Patent Document 1, Patent Document 2, and Patent Document 3 is operated in a non-lubricated state, the sliding resistance generated in the sliding member operating in a high temperature atmosphere Compared with the sliding resistance generated in the above, it can be greatly reduced.
As a result, the hysteresis of the operation characteristics associated with the opening and closing operation of the nozzle vanes is reduced, the turbocharger performance is stabilized, and a primary decrease in the supply air pressure (supercharge pressure) in the transient period of the turbocharger operation occurs. There averted acceleration is improved, flue gas state even Ru can be held constantly good condition.
[0017]
Further, according to the invention, the side clearance forming the carbon-based dry film in filling form side clearance (minute gap) between the inner surface of the case member inclusive slide surface and the turbine casing Roh Zuruben Is substantially zero (0), and the surfaces of the coatings having a lubricating function can be brought into sliding contact with each other to start operation of the supercharger.
Therefore, since the carbon-based dry film having a lubricating function is formed on the side clearance, the side clearance can be kept at a minimum value with a small frictional resistance, and the turbocharger can be operated. The amount of gas leakage from the clearance is reduced, and high turbine efficiency can be maintained.
Further, since the carbon-based dry film has a component common to the exhaust gas component, even if the carbon-based dry film disappears, the carbon of the exhaust gas adheres to the carbon-based dryness disappearing portion, and the carbon Has the same function as the carbon-based dry film.
[0018]
According to a second aspect of the invention relates to a surface treatment method of the variable nozzle mechanism components, acts on the turbine wheel of the exhaust gas flowed through the scroll passage in te bottle casing through the nozzle vanes rotatably supported to a nozzle mount And a variable displacement turbocharger in which the capacity of the turbine is variable by a variable nozzle mechanism that rotates the turbine wheel and transmits the driving force of the actuator to the nozzle vane via the link portion to change the blade angle of the nozzle vane. In the surface treatment method of the variable nozzle mechanism constituent member in the above , a cartridge type variable nozzle assembly in which the link portion, the nozzle mount and the nozzle vane are integrally assembled so as to be detachable from the turbine casing is integrally assembled with carbon. Using carbon ultrafine powder mainly composed of Was immersed in a solution consisting generated by fusion, the after drying to form a carbon-based dry film on the entire surface of the variable nozzle assembly components, then incorporating the variable nozzle assembly in the turbocharger It is characterized by that.
[0019]
According to this invention, the variable nozzle assembly of the variable nozzle mechanism in which the link portion, the nozzle mount and the nozzle vane are assembled together is integrally assembled in a solvent in which the carbon ultrafine powder is melted. A carbon-based dry film can be formed on the entire surface of the component member of the variable nozzle assembly composed of a plurality of parts with a very simple method and a small number of steps of dipping and drying.
[0020]
[0021]
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.
[0023]
FIG. 1 is a sectional view of an essential part showing the structure around a cartridge type variable nozzle assembly of a variable capacity supercharger according to a first embodiment of the present invention, and FIG. 2 is a fixed type variable nozzle assembly according to a second embodiment. FIG. 3 is a front view of the main part of the variable nozzle mechanism according to the third embodiment. FIG. 4 shows a nozzle vane according to a fourth embodiment, in which (A) is a side view of the nozzle vane and (B) is a view as seen from an arrow A in (A). FIG. 5 is a longitudinal sectional view of a variable capacity supercharger to which the present invention is applied.
[0024]
In FIG. 5 showing the structure of a turbocharger with a variable capacity turbine to which the present invention is applied, 30 is a turbine casing, 38 is a scroll passage formed in a spiral shape on the outer periphery of the turbine casing 30, and 44 is a turbine rotor. It is an exhaust gas outlet for sending out the exhaust gas that has been subjected to expansion work in the outside of the machine. Reference numeral 31 denotes a compressor casing, and 36 denotes a bearing housing for connecting the compressor casing 31 and the turbine casing 30.
[0025]
Reference numeral 34 denotes a turbine wheel, 35 denotes a compressor wheel, 33 denotes a turbine shaft that connects the turbine wheel 34 and the compressor wheel 35, and 37 denotes a bearing that is attached to the bearing housing 36 and supports the turbine shaft 33. 01 is the rotational axis of the turbine shaft 33.
A plurality of nozzle vanes 40 are arranged at equal intervals in the circumferential direction of the turbine on the inner peripheral side of the scroll passage 38, and a nozzle shaft 43 integrally formed with the nozzle mount 41 is attached to the turbine casing 30. The blade angle is changed by the rotation of the nozzle shaft 43.
[0026]
100 is a variable nozzle mechanism, 50 is an actuator of the variable nozzle mechanism 100, and the driving force of the actuator 50 is an actuator rod 51, a crank control unit 9 (see FIG. 3), a sleeve control unit 7 (see FIG. 3), and a lever assembly. The nozzle vane 40 is rotated to change its blade angle by rotating a ring assembly (not shown) that is driven to rotate around the rotational axis of the turbine shaft 33 via a product 42 (see FIG. 5). It has become. The actuator 50 is fixed to the compressor casing 31 by a bolt 55 via an actuator bracket 54.
[0027]
The present invention relates to a surface treatment structure and a surface treatment method for the constituent members of the variable nozzle mechanism 100 of the variable capacity supercharger shown in FIG.
That is, in FIG. 1 showing the first embodiment of the present invention, reference numeral 1 denotes a cartridge type variable nozzle assembly, the nozzle vane 40, a nozzle mount 41 that rotatably supports the nozzle vane 40 via a nozzle shaft 43, The nozzle support 45 fixed to the nozzle mount 41, the support member fixed to the end of the nozzle support 45, the nozzle vane 40 and the nozzle shaft 43, the actuator 50 and the actuator rod 51 are connected to the crank control unit 9 ( 3) and a link portion 2 that is connected via the sleeve control portion 7 and includes the lever assembly 42.
After the variable nozzle assembly 1 is assembled integrally with the components, the support member 46 fixed to the end of the nozzle support 45 is fitted into the fitting hole 47 formed in the turbine casing 30. by being configured to be eclipsed assembling detachably on the turbine casing 30.
[0028]
The structure of the variable nozzle mechanism 100 shown above is the same as the variable nozzle mechanism of a normal variable capacity supercharger.
The first method of surface treatment of the constituent members of the variable nozzle mechanism 100 according to the first embodiment of the present invention is to assemble the cartridge-type variable nozzle assembly 1 integrally, and then to make an ultrafine carbon powder mainly composed of carbon. The body is immersed in a solution formed by melting it in a xylene solution or the like (solvent). Next, the variable nozzle assembly 1 is taken out of the solution and naturally dried for a certain time. As a result, a carbon-based dry film is formed on the entire surface of the constituent member of the variable nozzle assembly 1.
Then, the variable nozzle assembly 1 made of an integral assembly in which the carbon-based dry film is formed is fitted into the fitting hole 47 formed in the turbine casing 30 by fitting the support member 46 of the nozzle support 45 into the fitting hole 47. The turbine casing 30 is detachably assembled.
[0029]
Further, the second method of surface treatment of the constituent members of the variable nozzle mechanism 100 is a sliding member that needs to be slidably contacted with a mating member and to be lubricated before the variable nozzle assembly 1 is assembled. On the surface of the member that can be assembled with a small gap between the sliding surface and the mating member, the ultrafine carbon powder mainly composed of carbon as described above is melted in a xylene solution or the like (solvent). The resulting solution is applied using a brush or the like and allowed to air dry for a certain period of time. As a result, a carbon-based dry film is formed on the sliding surface of the sliding member of the variable nozzle assembly 1 or the surface of the member to be assembled with a minute gap between the sliding member and the mating member.
Then, in the variable nozzle assembly 1 formed of an integral assembly on which the carbon-based dry film is formed, the support member 46 of the nozzle support 45 is fitted into the fitting hole 47 formed in the turbine casing 30 as in the first method. Is attached to the turbine casing 30 in a detachable manner.
[0030]
In the second embodiment shown in FIG. 2, reference numeral 1 denotes a fixed variable nozzle assembly, which includes a nozzle vane 40 with the nozzle shaft 43, a nozzle mount 41 that rotatably supports the nozzle vane 40, and the nozzle mount 41. The fixed nozzle support 45, the nozzle vane 40 and the nozzle shaft 43, and the actuator 50 and the actuator rod 51 are connected via the crank control unit 9 (see FIG. 3) and the sleeve control unit 7 (see FIG. 3). And the link portion 2 including the lever assembly 42 (see FIG. 5).
The fixed variable nozzle assembly 1 is configured to be assembled and fixed to the turbine casing 30 by fixing the nozzle support 45 to the turbine casing 30.
[0031]
The first method of surface treatment of the constituent members of the variable nozzle mechanism 100 in the second embodiment is a form in which the fixed variable nozzle assembly 1 is assembled integrally, and carbon is formed as in the first embodiment. The ultrafine carbon powder as the main component is immersed in a solution formed by melting in a xylene solution or the like (solvent). Next, the variable nozzle assembly 1 is taken out of the solution and naturally dried for a certain time. As a result, a carbon-based dry film is formed on the entire surface of the constituent member of the variable nozzle assembly 1.
Next, the variable nozzle assembly 1 on which the carbon-based dry film is formed is assembled and fixed to the turbine casing 30 by fixing the nozzle support 45 to the turbine casing 30.
[0032]
The second method of surface treatment of the variable nozzle mechanism 100 component in the second embodiment is as follows.
Before assembling the variable nozzle assembly 1, of the constituent members, assemble with a small gap between the sliding surface of the sliding member that needs to be lubricated by sliding against the mating member and the mating member. A solution formed by melting carbon ultrafine powder containing carbon as a main component in a xylene solution or the like (solvent) as described above is applied to the surface of the member using a brush or the like, and is naturally left for a certain period of time. Let dry. As a result, a carbon-based dry film is formed on the sliding surface of the sliding member of the variable nozzle assembly 1 or the surface of the member to be assembled with a minute gap between the sliding member and the mating member.
Next, as in the first method, the variable nozzle assembly 1 on which the carbon-based dry film is formed is assembled and fixed to the turbine casing 30 by fixing the nozzle support 45 to the turbine casing 30. .
[0033]
In the third embodiment shown in FIG. 3, the crank control portion 9, the ring control portion 8 and the sleeve control portion 7 in the link mechanism for connecting the drive lever 11 of the actuator 50 and the variable nozzle assembly 1 are provided. The surface of the member to be assembled with a small gap between the sliding surface of the sliding member or the mating member is formed by the first method or the second method in the first and second embodiments. A similar carbon-based dry film is formed.
[0034]
According to the first to third embodiments described above, the crank control unit 9, the ring control unit 8, and the sleeve control unit 7 in the link mechanism that connects the variable nozzle assembly 1, the actuator 50 and the variable nozzle assembly 1. Carbon produced by melting carbon ultrafine powder mainly composed of carbon in a solvent on the sliding surface of the sliding member constituting the member or the surface of the member that can be assembled with a minute gap between the member and the mating member Since the coating film of the solid lubricant made of a system dry film is formed, the sliding resistance of the sliding member operating in a high-temperature atmosphere can be reduced as in the prior art provided in Patent Document 1 or Patent Document 2. The sliding member can be greatly reduced as compared with a case where the sliding member is operated without lubrication.
Further, the gap value of the minute gap can be suppressed to a predetermined minimum value, the amount of gas leakage from the minute gap can be reduced, and high turbine efficiency can be maintained.
[0035]
In the fourth embodiment shown in FIG. 4, the first to second slide surfaces 40 a and 40 b that are formed at both ends of the nozzle vane 40 and rotate with a small gap with respect to the inner surface of the scroll passage 38. A carbon-based dry film is formed in the same manner as in the examples. In this case, the side clearance portion is filled with a carbon-based dry film on the slide surfaces 40a and 40b so that the clearance between the slide surfaces 40a and 40b and the inner surface of the scroll passage 38, that is, the side clearance becomes zero (0). In this state, the turbocharger is matched to the engine performance, and a steady operation is started.
As a result, the side clearance is filled with the carbon-based dry film having a lubricating function in the side clearance so that the frictional resistance is reduced, and the side clearance is minimized in such a low frictional resistance state. The turbocharger can be operated while maintaining the value, and the amount of gas leakage from the side clearance is reduced, so that high turbine efficiency can be maintained.
In the fourth embodiment, the carbon-based dry film is formed on the outer peripheral surface 43a of the nozzle shaft 43 that is rotatably fitted to the nozzle mount 41 to provide a solid lubricating function. Reduce frictional resistance.
[0036]
【The invention's effect】
According to the present invention as described above, the solid consists of both end slide surface and the carbon-based dry film carbon super fine powder produced by melting in a solvent mainly composed of carbon on the outer peripheral surface of the nozzle shaft Roh Zuruben lubricating Since the coating of the material is formed, the sliding member that operates in a high-temperature atmosphere has a sliding resistance as in the prior art provided in Patent Document 1 or Patent Document 2 without lubrication. This can be greatly reduced as compared with those operated in the above state.
As a result, the hysteresis of the operation characteristics associated with the opening and closing operation of the nozzle vanes is reduced, the turbocharger performance is stabilized, and a primary decrease in the supply air pressure (supercharge pressure) in the transient period of the turbocharger operation occurs. Thus, acceleration is improved, and the state of flue gas can always be kept in a good state.
[0037]
According to the present invention, the side clearance to form the carbonaceous dry film in filling form side clearance (minute gap) between the inner surface of the case member inclusive slide surface and the turbine casing Roh Zuruben Substantially zero (0) makes it possible to start operation of the supercharger by bringing the surfaces of the coatings having a lubricating function into sliding contact with each other.
Therefore, since the carbon-based dry film having a lubricating function is formed on the side clearance, the side clearance can be kept at a minimum value with a small frictional resistance, and the turbocharger can be operated. The amount of gas leakage from the clearance is reduced, and high turbine efficiency can be maintained.
Further, since the carbon-based dry film has a component common to the exhaust gas component, even if the carbon-based dry film disappears, the carbon of the exhaust gas adheres to the carbon-based dryness disappearing portion, and the carbon However, it has the same function as the carbon-based dry film and can maintain the required side clearance.
[0038]
Further, according to the second aspect , the variable nozzle assembly of the variable nozzle mechanism in which the link portion, the nozzle mount, and the nozzle vane are assembled together is integrally assembled, and the carbon ultrafine powder is melted. that is dried after immersion in there in a solvent, Ru can be formed of a carbon-based dry film on the entire surface of the very simple technique and less composed of a plurality of parts I following the step variable nozzle assembly of the components.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part showing a structure around a cartridge type variable nozzle assembly of a variable capacity supercharger according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of a main part showing a structure around a fixed variable nozzle assembly according to a second embodiment of the present invention.
FIG. 3 is a front view of a main part of a variable nozzle mechanism according to a third embodiment of the present invention.
4A and 4B show a fourth embodiment of the present invention, in which FIG. 4A is a side view of a nozzle vane, and FIG.
FIG. 5 is a longitudinal sectional view of a variable capacity supercharger to which the present invention is applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Variable nozzle assembly 2 Link part 7 Sleeve control part 8 Ring control part 9 Crank control part 11 Drive lever 30 Turbine casing 31 Compressor casing 33 Turbine shaft 34 Turbine wheel 35 Compressor wheel 36 Bearing housing 38 Scroll path 40 Nozzle vanes 40a, 40b Slide Surface 45 Nozzle support 46 Support member 43 Nozzle shaft 50 Actuator 100 Variable nozzle mechanism

Claims (2)

The exhaust gas flowing through the scroll passage in the turbine casing is caused to act on the turbine wheel through a nozzle vane rotatably supported by the nozzle mount to rotate the turbine wheel, and the driving force of the actuator is transmitted via the link portion. In a variable capacity turbocharger in which the capacity of the turbine is variable by a variable nozzle mechanism that transmits to the nozzle vane and changes the blade angle of the nozzle vane, among the members constituting the variable nozzle mechanism , both end slide surfaces of the nozzle vane and A variable capacity comprising a carbon-based dry film formed by melting a carbon ultrafine powder mainly composed of carbon in a solvent on an outer peripheral surface of a nozzle shaft that supports the nozzle vane on the nozzle mount. Surface treatment structure of type turbocharger. Exhaust gas that has flowed through the scroll passage in the turbine casing acts on the turbine wheel through a nozzle vane that is rotatably supported by the nozzle mount to rotate the turbine wheel, and the driving force of the actuator is transmitted via the link portion. In the surface treatment method of the variable nozzle mechanism constituent member in the variable displacement turbocharger in which the capacity of the turbine is variable by a variable nozzle mechanism that is transmitted to the nozzle vane and changes the blade angle of the nozzle vane, the link portion, the nozzle mount, and the nozzle vane A cartridge-type variable nozzle assembly that is integrally assembled to be attachable to and detachable from the turbine casing, and is a solution formed by melting carbon ultrafine powder containing carbon as a main component in a solvent. immersed in, and then dried their by the variable nozzle assembly The entire surface of the component to form a carbon-based dry film and then the surface treatment method for a variable capacity type turbocharger, wherein the incorporation of the variable nozzle assembly in the supercharger.

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