JP5067208B2 - Turbocharger - Google Patents

Description

  The present invention relates to a supercharger provided for increasing the output of an internal combustion engine and improving combustion efficiency.

  The supercharger is configured to rotate a compressor by a turbine driven by exhaust gas and to supercharge the compressed air from the compressor to an internal combustion engine.

  Conventionally, a rotating shaft extends from a turbine impeller, the rotating shaft passes through the compressor impeller, and a nut is hooked on the penetrating rotating shaft to fix the compressor impeller to the rotating shaft. And the compressor impeller rotate together.

  Since the turbine impeller is rotated by high-temperature exhaust gas, an iron-based heat-resistant alloy is used, and an aluminum alloy is used for the compressor impeller.

  In recent years, further increase in output of an internal combustion engine and improvement in combustion efficiency have been demanded, and a higher pressure ratio is required for the supercharger. However, the pressure ratio obtained from the structure of the supercharger, that is, the compressor impeller There was a limit to the number of revolutions.

  In the supercharger described above, since the rotary shaft passes through the compressor wheel, centrifugal stress is concentrated in the through hole. In particular, the maximum centrifugal stress is generated in the portion corresponding to the maximum diameter portion of the compressor wheel of the through hole, and the generated stress may exceed the allowable value. Therefore, the pressure ratio is limited due to the restriction that the maximum centrifugal stress is less than the allowable value.

  For this reason, as shown in Patent Document 1, the compressor impeller does not penetrate the rotating shaft, the compressor impeller has a solid structure, and the tip end of the rotating shaft is screwed and fixed to the compressor impeller. There is a machine.

  In a compressor impeller without a through hole (hereinafter referred to as a solid compressor impeller), the centrifugal stress is dispersed and the maximum centrifugal stress is greatly reduced. For this reason, the pressure ratio can be increased.

  In addition, a hexagonal tool hook is formed at the center tip of the compressor wheel so that the compressor wheel is screwed onto the rotation shaft of the compressor wheel, and a spanner or the like is formed on the tool hook. The compressor impeller was rotated by applying the tool and fixed to the rotating shaft.

  However, since the compressor wheel is made of an aluminum alloy and has a lower strength than that of a tool and is soft, there is a problem that the tool hook is easily damaged. Further, the compressor wheel needs to be attached to and detached from the rotating shaft for maintenance or the like, and the attachment / detachment work requires caution.

US Pat. No. 5,193,989

  In view of such circumstances, the present invention enables a turbocharger having a solid compressor wheel to be attached and detached from the compressor wheel and the rotating shaft reliably and without damaging the compressor wheel. To do.

  The present invention relates to a turbocharger having a compressor wheel with a solid structure screwed to a rotary shaft, wherein the tip of the compressor wheel is made of a material having higher strength and hardness than the compressor wheel, The present invention relates to a supercharger in which a jig having a portion is detachable and an engagement mechanism for transmitting torque is formed between the jig and the tip.

  According to the present invention, the engagement mechanism is composed of a recess formed at the tip and a connector protruding from the tool hook, and the recess and the connector are detachable. The jig is fitted on the tip, the engagement mechanism is formed on an engagement groove formed on one of the inner surface of the jig and the outer surface of the tip, and on the other The present invention relates to a supercharger that is formed of formed engaging ridges, and in which the engaging grooves and the engaging ridges are detachable.

  According to the present invention, the concave portion is a hole formed in a required number in the tip portion, the connector is a supercharger that is a rod-like protrusion that can be fitted into and removed from the hole, and the concave portion is , A slit groove radially engraved at the tip, and the connector is provided in a supercharger which is a rectangular piece projecting radially from the center and detachable from the slit groove.

  According to the present invention, in a supercharger having a compressor wheel with a solid structure screwed to a rotary shaft, the tip of the compressor wheel is made of a material having higher strength and hardness than the compressor wheel, Since a jig having a tool hanging portion can be attached and detached, and an engagement mechanism for transmitting torque is formed between the jig and the tip portion, when attaching or detaching the compressor wheel to the rotary shaft, A jig can be attached to the tip of the compressor wheel, and a tool can be applied to the jig to attach the compressor wheel to the rotary shaft with sufficient tightening force. Damage can be prevented, and further, the rotation balance of the compressor wheel can be adjusted by cutting the tip, and the rotation balance can be easily adjusted.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  First, an example of a supercharger in which the present invention is implemented will be described with reference to FIG.

  The supercharger 1 includes a turbine 3 and a compressor 4 that share a rotating shaft 2.

  The rotary shaft 2 is rotatably supported by a bearing housing 5 via a bearing 6, a turbine impeller 7 is provided at one end of the rotary shaft 2, and a compressor blade having a solid structure made of aluminum alloy at the other end. A car 8 is provided.

  The rotating shaft 2 and the turbine impeller 7 are integral, and the other end of the rotating shaft 2 is screwed and fixed to the compressor impeller 8.

  The turbine impeller 7 is accommodated in a turbine housing 12 attached to the bearing housing 5, and the compressor impeller 8 is accommodated in a compressor housing 13 attached to the bearing housing 5.

  The turbine 3 is configured by the turbine impeller 7, the turbine housing 12, and the like, and the compressor 4 is configured by the compressor impeller 8, the compressor housing 13, and the like.

  The turbine housing 12 has an exhaust gas inlet 14 and an exhaust gas outlet 15. Exhaust gas from an internal combustion engine flows into the exhaust gas inlet 14, and the exhaust gas outlet 15 supplies the exhaust gas by exhaust energy. The exhaust gas after rotating the turbine impeller 7 is exhausted.

  The compressor housing 13 has a suction port 16 and a discharge port 17, and the air sucked from the suction port 16 when the compressor wheel 8 is rotated by the turbine wheel 7 via the rotary shaft 2. And the compressed air is supplied to the internal combustion engine from the discharge port 17.

  Next, with reference to FIG. 2, a connecting portion between the rotary shaft 2 and the compressor wheel 8 will be described.

  A portion of the rotating shaft 2 that extends further than the bearing 6 is configured by a fitting shaft portion 21 having a smaller diameter with respect to the rotating shaft 2 and a screw portion 22 having a smaller diameter than the fitting shaft portion 21.

  The compressor wheel 8 is configured by a disk portion 8a and a boss portion 8b friction-bonded (friction welded) to the disk portion 8a. The disk portion 8a is made of, for example, an aluminum alloy, and the boss portion 8b For example, it is made of steel or steel alloy. Further, the joint surface 8c of the disk portion 8a and the boss portion 8b is set so as to be located on the turbine 3 side from the maximum diameter position M of the compressor impeller 8 and not reach the maximum diameter position M.

  A blind screw hole 23 is formed in the boss portion 8b, and the deepest position of the blind screw hole 23 (including the lower hole of the screw) is set so as not to reach the maximum diameter position M of the compressor impeller 8. Has been. Preferably, it is set so as not to reach the joint surface 8c. A fitting portion hole 24 having a diameter larger than that of the blind screw hole 23 is formed at the opening end of the blind screw hole 23.

  The compressor impeller 8 is screwed to the screw portion 22, and the fitting portion hole portion 24 is fitted to the fitting shaft portion 21, so that the core of the rotary shaft 2 and the compressor impeller 8 is aligned. It matches.

  Between the end surface of the disk portion 8a on the compressor impeller 8 side and the end surface of the rotary shaft 2, a thrust collar 25, a spacer ring 26, a thrust collar 27, and an oil drain 28 are provided from the rotary shaft 2 side. A thrust bearing 29 provided between the thrust collar 25 and the thrust collar 27 is fixed to the bearing housing 5.

  By tightening and fixing the compressor wheel 8 to the screw portion 22, the compressor wheel 8, the rotary shaft 2, the thrust collar 25, the spacer ring 26, the thrust collar 27, and the oil drain 28 are formed. Integrate and rotate.

  The bearing housing 5 is provided with an oil supply port 31, and further provided with a plurality of branched oil passages 32 communicating with the oil supply port 31, and a part of the conduction oil passage 32 is open to the bearing 6. , A part is opened to the outer peripheral surface of the spacer ring 26 through the thrust bearing 29. Accordingly, a part of the supplied lubricating oil is supplied to the outer peripheral surface of the spacer ring 26 through the conducting oil passage 32 and to the opposing surfaces of the thrust bearing 29 and the thrust collars 25 and 27. ing.

  Thus, the thrust bearing 29 and the thrust collars 25, 27 are lubricated, and the thrust load acting on the rotary shaft 2 is supported by the bearing housing 5 via the thrust bearing 29. ing.

  As described above, according to the present invention, the blind screw hole that is screwed into the blind screw hole 23 without penetrating the end portion of the rotary shaft 2 through the compressor impeller 8 and that is drilled in the compressor impeller 8. Since the deepest position of 23 does not reach the maximum diameter position M of the compressor wheel 8, the portion where the centrifugal force is maximized is solid, and the stress generated by the centrifugal force is uniformly dispersed, and the specific part Stress concentration is avoided.

  Next, the case where the compressor wheel 8 is screwed to the rotary shaft 2 will be described.

  As shown in FIG. 3, a plurality of recesses 34 are bored on the same circumference at the distal end portion (hereinafter referred to as the distal end portion) of the disk portion 8a on the suction port 16 side. In the present embodiment, the concave portion 34 shows a hole with a circular cross-section formed at a position divided into six equal circumferences.

  A jig 35 for rotating the compressor impeller 8 can be attached to and detached from the recess 34, and serves as means for transmitting torque to the compressor impeller 8 through the jig 35.

  4 and 5 show the jig 35. The jig 35 is made of steel that is higher in strength and hardness than the compressor wheel 8 or iron-based such as iron-based alloy steel. It is made of a metal material, and has a hexagonal head 36 as a tool hanging portion, and six connectors 37 protruding from the head 36. The connector 37 has a circular cross section. It is in a position divided into six equal circumferences and can be fitted to and removed from the recess 34.

  The recess 34 and the connector 37 constitute an engagement mechanism between the jig 35 and the compressor impeller 8.

  When the compressor impeller 8 is fastened to the rotary shaft 2, the connector 37 is fitted into the recess 34, and the jig 35 is attached to the tip of the disk portion 8a. A tool such as a spanner is applied to the head 36 to give a rotational force. The compressor wheel 8 is rotated via the jig 35, screwed onto the screw portion 22, and further tightened. After the compressor impeller 8 is attached, the jig 35 is removed.

  The number of the connectors 37 is determined by the magnitude of torque when tightening. Since the compressor wheel 8 is tightened through the jig 35 having high strength and high hardness, the jig 35 is not damaged by a tool. Further, torque is distributed and transmitted by the connector 37, so that the concave portion 34 is not damaged, and further, the compressor impeller 8 is not damaged, and a sufficient tightening force is given to the compressor impeller 8. Can do. The number of the connecting members 37 is preferably 6 or more than 6 in consideration of the material of the compressor wheel 8 being aluminum or the like.

  Next, the compressor wheel 8 has individual differences due to manufacturing errors and the like, and it is necessary to individually adjust the rotation balance.

  When adjusting the rotational balance of the compressor wheel 8, a part 38 of the front end portion of the disk portion 8 a is cut off, or a hole 39 is formed in the vicinity of the periphery of the front end portion. A metal member having a large specific gravity, such as a copper wire, is embedded.

  Since the tool for tightening or the like is not directly applied to the exposed portion of the tip of the disk portion 8a, there are few restrictions when the part 38 is cut off from the tip, and the adjustment of the rotation balance is easy. .

  The jig 35 and the disk portion 8a are engaged with each other in a hexagonal hole drilled around the recess 34, projecting around the connector 37, and the connector. The cross section of 37 may be hexagonal.

  FIG. 6 shows another engagement mechanism between the tip of the disk portion 8a and the jig 35. In the figure, for the sake of simplicity, the compressor wheel 8 is shown only at the tip.

  Three slit grooves 51 passing through the center of the disk portion 8a as recesses are formed at equal angular intervals in the disk portion 8a.

  The jig 35 has a hexagonal head portion 35a, and a connector 52 projects from the head portion 35a. The connector 52 is formed of a rectangular piece extending radially from the center in six directions at equal angles, and has a cross section of an asterisk shape, and can be fitted into and removed from the slit groove 51.

  The slit groove 51 and the connector 52 constitute an engagement mechanism, and torque applied to the jig 35 is transmitted to the disk portion 8a via the connector 52 and the slit groove 51.

  FIG. 7 shows still another engagement mechanism between the front end of the disk portion 8a and the jig 35. In the engagement mechanism, the jig 35 is externally fitted to the disk portion 8a.

  A required number, for example, six engaging grooves 53 are formed in the front end portion and outer peripheral surface of the disk portion 8a in parallel with the central axis. The engagement groove 53 is provided at a position divided into six equal circumferences, and the cross-sectional shape is, for example, a semicircular shape.

  A fitting hole 54 is formed in the jig 35, and an engagement protrusion 55 is formed on the inner peripheral surface of the fitting hole 54. The jig 35 is fitted to the disk portion 8a. The engaging protrusion 55 is fitted into the engaging groove 53.

  In the case of the present embodiment, the engagement protrusion 55 and the engagement groove 53 constitute an engagement mechanism.

  FIG. 8 shows still another engagement mechanism between the front end of the disk portion 8a and the jig 35. In the engagement mechanism, the jig 35 is the disk portion as in the engagement mechanism shown in FIG. It fits on 8a.

  A required number, for example, twelve engagement protrusions 56 are formed on the front end portion and the outer peripheral surface of the disk portion 8a in parallel with the central axis. The engagement protrusion 56 is provided at a position equally divided into 12 circumferences, and the cross-sectional shape is, for example, a triangular shape.

  A fitting hole 57 is formed in the jig 35, and an engagement groove 58 is formed on the inner peripheral surface of the fitting hole 57. The jig 35 is fitted into the disk portion 8a and the The engaging groove 58 and the engaging protrusion 56 are fitted.

  In the case of the present embodiment, the engagement protrusion 56 and the engagement groove 58 constitute an engagement mechanism.

  Various engagement mechanisms for transmitting torque between the jig 35 and the disk portion 8a are conceivable and are not limited to the engagement mechanisms described above.

It is sectional drawing which shows an example of the supercharger by which this invention is implemented. It is an expanded sectional view of the joint part of the rotating shaft and compressor impeller in this supercharger. It is a side view of the front-end | tip part of this compressor impeller. It is a side view of the jig | tool which can be fitted to the front-end | tip part of this compressor impeller. It is a front view of this jig. It is a perspective view which shows the other example of the front-end | tip part of a compressor impeller, and a jig | tool. It is a perspective view which shows the further another example of the front-end | tip part of a compressor impeller, and a jig | tool. It is a perspective view which shows the further another example of the front-end | tip part of a compressor impeller, and a jig | tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Supercharger 2 Rotating shaft 3 Turbine 4 Compressor 7 Turbine impeller 8 Compressor impeller 8a Disk part 8b Boss part 8c Joining surface 21 Fitting shaft part 22 Screw part 23 Blind screw hole 24 Fitting part hole part 34 Concave part 35 Osamu Tool 37 Connector 51 Slit groove 52 Connector 53 Engagement groove 55 Engagement ridge 56 Engagement ridge 58 Engagement groove

Claims (6)

Among screwed to the rotary shaft at the turbocharger having a compressor wheel of real structures, high strength than the compressor wheel, to allow Hamada' a jig having a high hardness material on the tip portion of the compressor wheel ,
The tip portion and the fitting portion of the jig form an engagement mechanism, and torque can be transmitted between the tip portion and the jig via the engagement mechanism.
The jig has a head on which a tool can be hung,
The compressor wheel is in a state where the jig is fitted to the tip,
A supercharger, wherein the jig is screwed onto the rotating shaft via the jig by a tool hung on the head of the jig, and the jig is removed after screwing . The engagement mechanism and the recess formed in the distal end portion, Engineering tools is composed of a projecting been consolidated from the engaging portion, supercharger of claim 1 wherein said recess coupling element is fitted detachably .   The jig is externally fitted to the tip, and the engagement mechanism is an engagement groove formed on one of the inner surface of the jig and the outer surface of the tip, and an engagement formed on the other The supercharger according to claim 1, wherein the supercharger is configured by a protrusion, and the engagement groove and the engagement protrusion are detachable.   3. The supercharger according to claim 2, wherein the concave portion is a hole formed in a required number in the tip portion, and the connector is a rod-like protrusion that can be fitted into and removed from the hole.   The supercharger according to claim 2, wherein the recess is a slit groove radially engraved at the tip, and the connector is a rectangular piece projecting radially from the center and detachable from the slit groove. .   The supercharger according to claim 4, wherein the tip portion can be partially removed by removing the hole, and the balance can be adjusted by partially removing the tip portion.

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