Vehicle Firewall Sound Insulation with Integrated Hold-Down Protrusions
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Solution Overview
Problem
The existing methods for manufacturing sound insulation elements for vehicle end walls require costly molding tools with hold-down pins to maintain the position of the plastic carrier layer, leading to unsatisfactory results and acoustic disadvantages due to cavities formed by these pins.
Innovation Solution
Incorporating hold-down projections directly into the plastic carrier layer of the sound insulation element, which are embedded in the sound-damping material and extend into the sound-damping layer, eliminating the need for external mold pins and ensuring the sound-damping material surrounds the hole edges effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mold retaining pins are used to hold the plastic carrier layer during molding, then the plastic carrier layer position is maintained, but manufacturing costs increase and cavities are formed in the sound-absorbing layer
Solution Approach 1:
The patent merges the retaining function into the plastic carrier layer itself by integrating retaining projections directly into the carrier layer structure. These projections extend through the sound-absorbing layer and anchor it to the carrier layer, eliminating the need for separate mold retaining pins. This integration reduces manufacturing tool complexity and costs while maintaining position stability during the molding process.
Solution Approach 2:
The plastic carrier layer serves its own retaining function through the integrated retaining projections, rather than requiring external mold retaining pins. The carrier layer with its built-in projections automatically maintains position stability and anchors the sound-absorbing layer during molding, making the system self-sufficient and reducing dependency on complex molding tools.
2Manufacturing precision
If mold retaining pins are used to hold the plastic carrier layer, then positioning is maintained, but acoustic performance deteriorates due to cavities
Solution Approach 1:
The retaining function is merged into the plastic carrier layer structure through integrated retaining projections. These projections extend through the sound-absorbing layer without creating cavities, as they are seamlessly integrated into the material structure. This eliminates the harmful cavities that would otherwise form around external mold retaining pins, preserving acoustic performance while maintaining positioning stability.
3Ease of manufacture
If sound-absorbing material is molded onto the plastic carrier layer with holes, then hole edges are protected, but the plastic carrier layer floats in the mold without retaining pins
Solution Approach 1:
The retaining projections are merged into the plastic carrier layer structure, providing both hole edge protection and position stability simultaneously. The projections extend through the sound-absorbing layer and anchor it to the carrier layer, preventing floating during molding while ensuring sound-absorbing material properly surrounds the hole edges for mechanical protection.
Data Source
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AI summary
The invention relates to a sound insulation element for the firewall of a vehicle body, which firewall is arranged between the passenger compartment and the engine compartment. Said sound insulation element is provided with a composite component, which has a plastic support layer (16) and a sound-damping layer (18) joined to the plastic support layer, the composite component having at least one first through-opening. The composite component has a front side, which faces the passenger compartment when the composite component is installed and which is formed by the outer face of the plastic support layer (16), and a rear side, which lies against the firewall and is formed by the outer face of the sound-damping layer (18), which outer face faces away from the plastic support layer (16). On and/or at an offset to the hole edge of the support layer hole, on the inner face of the plastic support layer (16), which inner face faces away from the outer face of the plastic support layer (16) and thus faces the sound-damping layer (18), at least one hold-down protrusion (72) protrudes from the plastic support layer, which hold-down protrusion is embedded in the sound-damping material of the sound-damping layer (18) and the free end of which hold-down protrusion, facing away from the plastic support layer (16), is substantially flush with the outer face of the sound-damping layer (18), which outer face faces away from the plastic support layer (16).