Noise reduction device of engine crankshaft pulley and crankshaft pulley

Abstract

The utility model relates to the field of vehicle engines, in particular to a noise reduction device of an engine crankshaft pulley and the crankshaft pulley. The device is composed of a sound absorption layer, a screw hole bush and a sound insulation shell, the sound insulation shell is matched with the inner contour of the crankshaft belt pulley, the sound absorption layer is arranged in the sound insulation shell, and the screw hole bush is embedded in the circumference of the sound insulation shell and corresponds to a threaded hole in the crankshaft belt pulley. The crankshaft pulley can effectively reduce near-field noise of the crankshaft pulley, improves sound quality of an engine, and meanwhile has the advantages of being convenient to assemble, durable, high in reliability and the like.

Description

Technical Field

[0001] This utility model relates to the field of engines, specifically to a noise reduction device for an engine crankshaft pulley and the crankshaft pulley itself. Background Technology

[0002] During engine operation, the crankshaft system is subjected to excitations from combustion within the cylinder, timing sprocket loads, and impact loads from the transmission system, causing it to vibrate. This vibration noise is transmitted to the outside of the engine through the crankshaft pulley at the end of the crankshaft. The sound insulation performance of a single-layer solid plate in the low-frequency range is mainly determined by its stiffness. In the patent (200610063743.9 Noise Insulation Pulley), the soundproof cover is made of rubber. Rubber is less stiff than plastic, which also results in lower sound insulation performance for rubber compared to plastic.

[0003] The utility model (202120130468.8 A crankshaft vibration damping pulley sound insulation cover, engine and vehicle) uses a sound insulation cover and sound insulation cotton for sound insulation and absorption. The sound insulation cover is made of plastic or metal and serves as sound insulation. The sound insulation cotton is attached to the sound insulation cover and serves as sound absorption. The thickness of the material is an important parameter affecting the sound absorption performance. This utility model does not mention that the thickness of the sound-absorbing material is relatively thin, nor does it specify the thickness. The sound insulation cover is fixed to the pulley by buckles and achieves an interference fit with a rubber sealing ring. However, rubber is prone to aging, and aging may cause the sound insulation cover to loosen.

[0004] The utility model (201820679594.7, a sound insulation device for a vibration damping pulley of a turbocharged engine) has a sound insulation cover with multiple layers of sound-absorbing and insulating materials, including foam, sound insulation sleeve, glass wool layer, semi-cured felt layer, non-woven fabric layer, and perforated aluminum foil layer. This complex structure poses a certain risk to the device's durability and reliability. Furthermore, the installation process requires adjusting the relative position between the pulley and the sound insulation cover, making it relatively cumbersome. Utility Model Content

[0005] To address the aforementioned shortcomings, this utility model proposes a novel noise reduction device for crankshaft pulleys and a crankshaft pulley itself. This device effectively reduces near-field noise from the pulley and also boasts advantages such as simple and reliable structure, convenient assembly, wide adaptability to various operating conditions, and high durability and reliability. The specific technical solution is as follows:

[0006] A noise reduction device for an engine crankshaft pulley comprises a sound-absorbing layer, a threaded bushing, and a sound-insulating housing. The sound-insulating housing matches the inner contour of the crankshaft pulley. The sound-absorbing layer is disposed inside the sound-insulating housing. The threaded bushing is embedded in the circumference of the sound-insulating housing, corresponding to the threaded hole on the crankshaft pulley. The outer shape of the sound-insulating housing is arc-shaped to avoid concave shapes and prevent sound energy focusing. The threaded bushing is embedded in the sound-insulating housing by injection molding. The threaded bushing and the sound-insulating housing are fitted with a T-shaped boss structure to effectively prevent axial movement.

[0007] Furthermore, the sound-absorbing layer is made of PUR, which has been foamed and has a density of 100~140 kg / m³. 3 The porosity is greater than 90%, and the thickness is 2~50mm.

[0008] Furthermore, the sound-absorbing layer is fixed to the soundproof cover housing by adhesive application.

[0009] Furthermore, the thickness of the soundproof shell is greater than 2.0 mm, and the material is selected as PA6+GF or PA66+GF according to the temperature resistance and strength requirements.

[0010] Furthermore, the screw hole bushings are evenly arranged circumferentially, with a quantity of 4 to 6, and the material is steel 08A.

[0011] This utility model also provides a crankshaft pulley equipped with a noise reduction device for an engine crankshaft pulley. The noise reduction device for the engine crankshaft pulley is fixed to the crankshaft pulley by bolts. The sound-absorbing layer is close to the side of the crankshaft pulley and contacts and cooperates with the pulley. The bolts pass through the threaded bushing and the threaded hole on the crankshaft pulley to fix the noise reduction device for the engine crankshaft pulley to the crankshaft pulley.

[0012] This invention, through the rational arrangement and structural design of the sound-absorbing layer and sound-insulating layer-soundproof cover, effectively reduces noise by up to 2.0 dBA through both sound absorption and sound insulation, demonstrating significant results. The noise reduction device is bolted to the crankshaft pulley, a simple, reliable, and widely adaptable installation method. The bolted bushing is strategically embedded in the soundproof cover, effectively limiting movement and preventing the cover from being damaged by the bolts during installation. Furthermore, the T-shaped boss structure of the two components effectively prevents axial movement. This invention absorbs and isolates vibration noise transmitted from the crankshaft system to the crankshaft pulley, effectively improving the problem of high near-field noise from the crankshaft pulley and enhancing the engine's operating sound quality. Attached Figure Description

[0013] Figure 1 Schematic diagram of the noise reduction device of this utility model;

[0014] Figure 2 Figure 1A magnified view of a portion of the image;

[0015] Figure 3 Assembly diagram of the noise reduction device and crankshaft pulley of this utility model;

[0016] Figure 4 Example of noise reduction effect diagram;

[0017] Figure 5 Example: Engine noise quality diagram.

[0018] Figure label:

[0019] 1—Sound-absorbing layer; 2—Threaded hole bushing; 3—Sound insulation housing; 20—T-shaped boss; 21—Crankshaft pulley; 22—Noise reduction device for engine crankshaft pulley; 23—Bolt. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] like Figure 1 As shown, a noise reduction device for an engine crankshaft pulley comprises a sound-absorbing layer 1, a threaded bushing 2, and a sound-insulating housing 3. The sound-insulating housing 3 matches the inner contour of the crankshaft pulley. The sound-absorbing layer 1 is fitted inside the sound-insulating housing 3. The threaded bushing 2 is embedded in the circumference of the sound-insulating housing 3, corresponding to the threaded hole on the crankshaft pulley. The outer shape of the sound-insulating housing is arc-shaped to avoid concave shapes and prevent sound energy focusing. The threaded bushing is embedded in the sound-insulating housing by injection molding. The threaded bushing and the sound-insulating housing are fitted with a T-shaped boss 20 structure to effectively prevent axial movement. Figure 2 As indicated by the arrow.

[0022] The sound-absorbing layer 1 is made of PUR, which has been foamed and has a density of 100~140 kg / m³. 3 The sound-absorbing layer 1 has a porosity greater than 90% and a thickness of 2-50 mm. It is positioned near the sound source (pulley) and contacts the pulley. The sound-absorbing layer 1 is fixed to the sound-insulating housing 3 by adhesive application.

[0023] The soundproof housing 3 also serves as a sound insulation layer, further isolating sound waves transmitted through the sound-absorbing layer 1. The thickness of the soundproof housing 3 is greater than 2.0 mm, and the material is selected as PA6+GF or PA66+GF based on temperature resistance and strength requirements. Screw hole bushings 2 are evenly arranged circumferentially, with a quantity of 4 to 6. The material of the screw hole bushings 2 can be steel 08A, serving as bolt limiters during the installation of the noise reduction device.

[0024] like Figure 3 The diagram shows the assembly of the noise reduction device. The noise reduction device 22 is fixed to the crankshaft pulley 21 by bolts 23. The bolts 23 pass through the threaded bushing 2 and the threaded hole on the crankshaft pulley 21 to fix the noise reduction device to the crankshaft pulley 21.

[0025] Engine bench noise tests showed that the noise reduction device of this invention effectively reduced the total sound pressure level of the engine front end near-field 1m under idling conditions by 2.0 dBA. Figure 4 As shown.

[0026] Idle engine noise quality (loudness, sharpness, and articulation index) is effectively improved by 5-10%, such as... Figure 5 As shown.

[0027] The preferred embodiments of this patent have been described in detail above. However, this patent is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this patent.

Claims

1. A noise reduction device for an engine crank pulley, characterized by: The device is composed of a sound absorption layer (1), a threaded hole bushing (2) and a sound insulation shell (3), the sound insulation shell (3) matches the inner contour of the crankshaft pulley, the sound absorption layer (1) is sleeved inside the sound insulation shell (3), the threaded hole bushing (2) is embedded at the circumference of the sound insulation shell (3) and corresponds to the threaded hole on the crankshaft pulley; the outer side of the sound insulation shell (3) is in the shape of a circular arc; the threaded hole bushing (2) is embedded in the sound insulation shell (3) by injection molding, and the threaded hole bushing (2) and the sound insulation shell (3) are arranged in a T-shaped boss (20) structure cooperation.

2. The noise reduction device of an engine crank pulley as claimed in claim 1, characterized in that: The material of the sound absorption layer (1) is PUR, which is treated by foaming process, with density of 100-140 kg / m 3 , porosity of more than 90%, and thickness of 2-50 mm.

3. The noise reduction device of an engine crank pulley as claimed in claim 2, characterized in that: The sound absorption layer (1) and the sound insulation shell (3) are fixed by a dispensing method.

4. The noise reduction device of an engine crank pulley as set forth in claim 1, wherein: The thickness of the sound insulation shell (3) is greater than 2.0 mm, and the material is selected from PA6+GF or PA66+GF according to the requirements of temperature resistance and strength.

5. The noise reduction device of an engine crank pulley as claimed in claim 1, characterized in that: The threaded hole bushing (2) is arranged uniformly in the circumferential direction, the number is 4-6, and the material is selected from steel 08A.

6. A crank pulley with a noise reduction device of the crank pulley according to any one of claims 1 to 5, characterized by: The noise reduction device (22) of the engine crankshaft pulley is fixed on the crankshaft pulley (21) by a bolt (23), the sound absorption layer (1) is close to the side of the crankshaft pulley (21) and is in contact with the pulley, and the bolt (23) passes through the threaded hole bushing (2) and the threaded hole on the crankshaft pulley (21) to fix the noise reduction device (22) of the engine crankshaft pulley on the crankshaft pulley (21).

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