Cylinder Block Thermal Spray Coating Heat Control
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Solution Overview
Problem
The formation of thermally sprayed coatings on cylinder blocks leads to temperature rises and accumulation of internal stresses, causing deformations that complicate machining and finishing processes.
Innovation Solution
Controlling the heat input by reciprocating a thermal spray gun along the axial direction while rotating it, and optionally cooling the cylinder block, to reduce temperature rises and internal stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermal spray coating is applied to the cylinder bore, then the anti-abrasion property is improved, but the cylinder block temperature rises and internal stresses accumulate causing deformations
Solution Approach 1:
The thermal spray gun is reciprocated along the axial direction in periodic cycles while rotating, controlling the heat input to the cylinder block. This periodic action allows the coating to be applied while limiting temperature rise and internal stress accumulation, thereby preventing deformations and maintaining manufacturing precision.
Solution Approach 2:
The thermal spray gun is rotated during the coating process to distribute heat input dynamically around the cylinder bore. This dynamic rotation combined with axial reciprocation ensures uniform coating application while controlling thermal accumulation, preventing localized overheating and associated deformations.
2Ease of manufacture
If the cylinder block is machined in the state where internal stresses are accumulated, then pre-stage machining is completed, but deformations occur when internal stresses are released
Solution Approach 1:
The invention applies thermal spray coating with controlled heat input before pre-stage machining operations. By controlling the coating process to minimize internal stress accumulation from the outset, the subsequent machining operations can be performed without significant deformations occurring when stresses are released, simplifying the manufacturing process.
3Strength
If thermal spray coating is applied to improve anti-abrasion property, then coating thickness increases, but heat input causes temperature rise and complicates finishing operations
Solution Approach 1:
The periodic reciprocation of the thermal spray gun controls heat input while maintaining adequate coating thickness for anti-abrasion protection. This controlled thermal process prevents excessive temperature rise and internal stress accumulation, resulting in minimal deformation that simplifies subsequent finishing operations and reduces process complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach restricts deformations and simplifies subsequent machining and finishing operations by maintaining lower internal stresses and consistent coating thickness.
Implementation Method 1
melted droplets generated by heating and melting the wire by a heat source such as plasma arc
Implementation Method 2
controlling the heat input to the cylinder block when forming a thermally sprayed coating by reciprocating a thermal spray gun along an axial direction in the cylinder bore while rotating the thermal spray gun
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A thermally sprayed coating (5) is formed on an inner surface of a cylinder bore (3) of a cylinder block (1) by using a thermal spray gun (7). The thermal spray gun (7) is reciprocated along an axial direction in the cylinder bore (3) while being rotated, and injects melted droplets (10) generated by melting a wire made of a ferrous material from a nozzle (9) at its end. At this time, a moving speed of the thermal spray gun (7) along the axial direction into the cylinder bore (3) is made equal-to or larger-than a predetermined value, and the number of reciprocating cycles of the thermal spray gun (7) along the axial direction into the cylinder bore (3) is made equal-to or larger-than a predetermined value.