Engine pulley structure

Abstract

The present invention provides a pulley structure of an engine to prevent abnormal noise from being generated between a pulley and a torsional vibration damper. The pulley structure includes a step portion formed in a shape that shields a cavity in a radial direction of the cavity. The cavity is formed at a portion where the pulley and the torsional vibration damper face each other.

Description

Technical Field

[0001] The present invention relates to a pulley structure of an engine, and more particularly, to a pulley structure for preventing abnormal noise from being generated between a pulley and a torsional vibration damper. Background Art

[0002] like Figure 1 As shown, a mild hybrid vehicle structure equipped with a 48V battery is a structure that omits the AC generator of a conventional vehicle and installs a 48V battery, a DC / DC converter, and a mild hybrid starter generator (MHSG). The 48V mild hybrid structure receives the power required by the vehicle through the electric motor within an operating range such as starting and acceleration, and has the advantage of improving the fuel efficiency of the vehicle through a regenerative braking function that recovers energy generated during vehicle braking and stores the energy in a battery.

[0003] However, due to the frequent starting of the MHSG and the use of torque assist and regenerative braking during driving, as well as the torsional vibration of the engine, the 48V mild hybrid structure increases the belt load, which reduces the durability of the belt. In other words, the torsional vibration of the engine increases the performance of the tensioner, causing belt slippage, thereby deteriorating the life of the auxiliary drive belt structure and causing abnormal noise during operation.

[0004] Therefore, a technology has been developed that installs a pulley separator on the pulley to stabilize the vibration of the tensioner and reduce the slip of the belt through torsional vibration. However, although the application of the pulley separator improves the durability and noise of the belt and tensioner, this structure causes noise-vibration-harshness (NVH) due to interference between the structures.

[0005] For example, in a structure with a torsional vibration damper mounted on a pulley, abnormal noise is amplified in a specific frequency band. This occurs between the pulley and the torsional vibration damper.

[0006] The foregoing content is only intended to help understand the background of the present invention and does not mean that the present invention falls within the scope of the relevant technologies known to those skilled in the art. Summary of the invention

[0007] The present invention provides a pulley structure of an engine, which prevents abnormal noise from being generated between a pulley and a torsional vibration damper. The structure of the present invention may include: a step portion formed in a shape that shields a cavity provided at a portion where the pulley and the torsional vibration damper face each other in a radial direction.

[0008] The torsional vibration damper may be coupled to the pulley in the axial direction of the pulley; and a step portion may be formed on the torsional vibration damper to protrude toward the pulley. A cavity may be formed between one surface including an edge of one end of the pulley in the axial direction and the torsional vibration damper facing the one surface; and the step portion may be formed in a protruding shape to cover an entrance of the cavity.

[0009] The step portion may be formed in a shape covering an edge of one end of the pulley. In addition, the step portion may be formed with a predetermined gap in a radial direction relative to an edge of one end of the pulley. The inertia ring may be coupled to the torsional vibration damper along a circumferential direction of the torsional vibration damper. The step portion may be formed in a shape protruding toward the pulley so as to gradually increase in height at one surface of the inertia ring. The pulley separator may be coupled to the pulley, and the torsional vibration damper may be coupled to the pulley separator.

[0010] According to the present invention, a step portion can be formed in the radial direction of the cavity to block the sound waves generated in the cavity and prevent the sound waves from transmitting to the outside of the cavity, which changes the resonance characteristics in the pulley structure and prevents abnormal noise from being generated in the engine structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other objects, features and other advantages of the present invention will be more clearly understood through the following detailed description in conjunction with the accompanying drawings, in which:

[0012] Figure 1 is a view showing a 48V light power structure according to the related art;

[0013] Figure 2 is a view showing a configuration in which a cavity is opened in a radial direction in a conventional pulley structure according to the related art;

[0014] Figure 3 is a view showing a state before a torsional vibration damper and a pulley are coupled to each other according to an exemplary embodiment of the present invention; and

[0015] Figure 4 2 is a view showing a configuration in which a step portion shields a cavity in a radial direction in a pulley structure according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0016] It will be understood that the term "vehicle" or "vehicular" or other similar terms used herein generally include motor vehicles, such as sports utility vehicles (SUVs), buses, trucks, various commercial vehicles; ships including various boats, vessels, aircraft, etc.; and include hybrid vehicles, electric vehicles, combustion vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels from non-petroleum resources).

[0017] The terms used herein are only used to illustrate the purpose of specific embodiments and are not intended to limit the present invention. As used herein, the singular forms "one", "a kind of" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that when used in this specification, the words "include" and / or "comprise" specify the presence of the features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. As used herein, the word "and / or" includes any and all combinations of one or more related listed items.

[0018] Exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0019] The pulley structure 1 of the engine according to the present invention can be applied to vehicles with a 48V mild hybrid structure, such as Figure 1 As shown, moreover, it can be applied to a vehicle in which the starter generator is connected to the engine in other ways. In other words, the power transmitted from the crankshaft of the engine can be transmitted to the mild hybrid starter generator (MHSG) through the pulley electric structure, and the torsional vibration damper 7 can be installed on the pulley 3. In particular, the present invention can eliminate the abnormal noise generated in the pulley structure 1 through the structural improvement of the torsional vibration damper 7.

[0020] Reference Figure 3 and Figure 4 , the technical features of the present invention will be described in detail. The present invention may include a cavity 17 formed at the portion where the pulley 3 and the torsional vibration damper 7 face each other, and a step portion 15 closing the cavity in the radial direction of the cavity 17. The step portion 15 may be formed as a flange or other protrusion or a stepped component with a protrusion (for example, a part of the component extends further than the rest).

[0021] In addition, the pulley separator 5 can be coupled to the shaft of the pulley 3 to reduce torsional vibration, and the torsional vibration damper 7 can be fastened to the pulley separator 5 in its axial direction by bolts or other fastening mechanisms. In other words, the cavity 17 formed between the pulley separator 5 and the torsional vibration damper 7 generates resonance, which is a sound box formed due to the vibration of the engine and the pulley separator 5, and the resonance occurs in a specific frequency band.

[0022] In the related art, the cavity is formed as a structure opened in the radial direction, and therefore, the resonance occurring at a specific frequency is emitted to the outside of the cavity, thereby causing abnormal noise in the engine. Therefore, the step portion 15 of the present invention is arranged in the radial direction of the cavity 17, and therefore, the sound waves generated in the cavity 17 are blocked by the step portion 15 and cannot be emitted to the outside of the cavity 17, thereby changing the resonance characteristics in the pulley structure to prevent abnormal noise from occurring in the engine structure.

[0023] Reference Figure 4 In the configuration of the exemplary embodiment of the step portion 15, the torsional vibration damper 7 may be coupled to the pulley 3 in the axial direction of the pulley. In addition, the step portion 15 may be formed on the torsional vibration damper 7 to protrude toward the pulley 3.

[0024] In other words, the step portion 15 may be formed on the torsional vibration damper 7 to protrude toward the pulley 3, and thus, the protruding step portion 15 may shield the cavity 17. More specifically, the cavity 17 may be formed between one surface including an edge of one end portion of the pulley 3 in the axial direction and the torsional vibration damper 7 opposite to the one surface (e.g., disposed opposite to the one surface). Therefore, the step portion 15 may be formed in a shape that protrudes toward the pulley 3 and covers the entrance of the cavity 17. In other words, the step portion 15 may be formed in a shape that covers and surrounds the entrance of the cavity 17 in the radial direction. Therefore, the sound waves generated in the cavity 17 are not emitted to the outside of the cavity 17.

[0025] In addition, the step portion 15 may be formed in a shape having an edge covering one end of the pulley 3. In other words, the step portion 15 may cover the entrance of the cavity 17 and shield a portion adjacent to the entrance to block the sound waves generated in the cavity 17 from being radiated in the radial direction. On the other hand, the step portion 15 may be formed with a predetermined gap g in the radial direction relative to the edge of the end of the pulley 3. In other words, the step portion 15 may be arranged in the radial direction of the cavity 17 to prevent the sound waves from being emitted to the outside, and may be formed to be spaced apart from the edge of one end of the pulley 3 (e.g., not in contact with the edge), thereby preventing the generation of friction noise due to interference between the step portion 15 and the edge of one end of the pulley 3.

[0026] As described above, the step portion 15 of the present invention may be formed on the torsional vibration damper 7, and formed on the inertia ring 13 of the torsional vibration damper 7. For example, the inertia ring 13 may be coupled along the circumferential direction of the torsional vibration damper 7, and the inertia ring 13 may be a mass body that reduces the torsional vibration of the engine with sufficient inertia force. For reference, the damper rubber 11 may be disposed on the inner side of the inertia ring 13, and the damper hub 9 may be disposed on the inner side of the rubber to couple the damper hub 9 to the pulley separator 5.

[0027] In addition, a step portion 15 may be formed on one surface of the inertia ring 13 facing the pulley 3, which protrudes toward the pulley 3 and is stepped (e.g., the height gradually increases or protrudes). In other words, the step portion 15 may be formed in a step shape (e.g., a flange or a raised protrusion) on the inertia ring 13, and the step portion may be located in the radial direction of the cavity 17 to prevent the sound waves generated in the cavity 17 from being emitted to the outside of the cavity 17. In addition, the step portion 15 may be integrally formed on the inertia ring 13 to eliminate a separate component for providing the step portion 15, thereby simplifying the overall structural configuration. In other words, multiple components are not required to form a step portion covering the cavity.

[0028] As described above, in the present invention, the step portion 15 can be arranged along the radial direction of the cavity 17 to prevent the sound waves generated in the cavity 17 from being emitted to the outside of the cavity 17, thereby changing the resonance characteristics of the pulley structure and thus preventing abnormal noise from being generated in the engine structure.

[0029] Although the present invention has been described in detail only with respect to the above exemplary embodiments, many changes and modifications within the scope of the technical disclosure of the present invention will be apparent to those skilled in the art and naturally fall within the scope of the appended claims.

Claims

1. A pulley structure of an engine, comprising: a step portion formed in a shape shielding a cavity in a radial direction, wherein the cavity is provided at a portion where the pulley and the torsional vibration damper face each other; an inertia ring coupled to the torsional vibration damper in a circumferential direction of the torsional vibration damper, wherein the step portion is formed to be stepped at one surface of the inertia ring in a protruding shape extending toward the pulley; a pulley decoupler coupled to the pulley; A shock absorber rubber is arranged on the inner side of the inertia ring; and a shock absorber hub disposed inside the shock absorber rubber, wherein the shock absorber hub is directly coupled to the pulley separator, wherein the cavity resonates in a specific frequency band due to vibrations of the engine and the pulley separator, wherein the sound waves generated by the cavity are blocked by the step portion, and The cavity is formed by separating the pulley separator and the torsional vibration damper in the axial direction and extends in the radial direction.

2. The pulley structure of the engine according to claim 1, wherein: The torsional vibration damper is coupled to the pulley in an axial direction of the pulley, and the step portion is formed on the torsional vibration damper to protrude toward the pulley.

3. The pulley structure of the engine according to claim 2, wherein: The cavity is formed between one surface of the pulley including an edge of one end in the axial direction and a torsional vibration damper facing the one surface, and the step portion is formed in a protruding shape to cover an entrance of the cavity.

4. The pulley structure of the engine according to claim 3, wherein: The step portion is formed in a shape covering an edge of one end portion of the pulley.

5. The pulley structure of the engine as claimed in claim 4, wherein: The step portion is formed with a predetermined gap in a radial direction relative to an edge of one end portion of the pulley.

6. The pulley structure of the engine according to claim 1, wherein: The torsional vibration damper is coupled to the pulley decoupler.

7. A vehicle having the pulley structure according to claim 1.

Images