Knock Sensor Mounting Boss Positioning in Unit Swing Engine
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Solution Overview
Problem
In unit swing engines for straddle-type vehicles, the attachment and detachment of knock sensors are complicated due to their placement below the intake system, leading to increased seat height and interference with the intake pipe, which complicates the mounting process and affects knocking detection accuracy.
Innovation Solution
A knock sensor mounting structure is designed where the mounting boss on the cylinder block is positioned to avoid overlapping with the intake pipe, with the screw axis offset to prevent interference, allowing the intake pipe to be placed at a lower position, and the knock sensor is mounted on a boss that projects outward, facilitating attachment and detachment while improving knocking detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the knock sensor is disposed immediately below the intake system including the intake pipe, then the knock sensor can be protected from stones and dirt flying from the ground, but the attachment/detachment work becomes complicated and the intake pipe must be disposed at a higher position which increases seat height
Solution Approach 1:
The mounting boss is designed to project outward from the side wall of the cylinder block in the widthwise direction, moving the knock sensor mounting position from the vertical dimension (below intake pipe) to the lateral dimension (side of cylinder block). This dimensional shift allows the sensor to be accessible from the side for easy attachment/detachment while maintaining protection from ground debris, and enables the intake pipe to be positioned lower without interfering with sensor maintenance.
2Device complexity
If the intake pipe is disposed at a higher position to prevent the knock sensor from protruding upward and interfering with the intake pipe, then interference with the intake pipe is avoided, but the height of the riding seat must be increased
Solution Approach 1:
By relocating the knock sensor mounting position to the side of the cylinder block rather than below the intake pipe, the invention resolves the spatial conflict between the sensor and intake pipe in the vertical dimension. This allows the intake pipe to be positioned lower, reducing the overall height requirement and enabling a lower riding seat while maintaining proper clearance between components.
3Ease of manufacture
If the mounting boss is formed on the upper wall of the cylinder block at a position overlapping with the intake pipe, then the knock sensor can be mounted on the cylinder block, but the intake pipe gets in the way during attachment/detachment work
Solution Approach 1:
The mounting boss is extracted from the upper wall of the cylinder block and repositioned on the side wall, projecting outward in the widthwise direction. This extraction removes the conflict with the intake pipe routing, allowing the knock sensor to be mounted securely on the cylinder block while enabling accessible attachment/detachment operations from the side without interference from the intake pipe.
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 configuration simplifies the attachment and detachment of the knock sensor, reduces seat height interference, and enhances knocking detection accuracy by positioning the sensor to effectively detect vibrations without interference from the intake pipe or cam chain noise.
Implementation Method 1
a knock sensor to detect knocking is fastened, with a screw member, to a mounting boss formed on an upper wall of the cylinder block
Data Source
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AI summary
To enable attachment/detachment work of a knock sensor to be facilitated and an intake system to be disposed at a low position in a unit swing engine in which: an intake pipe that stands upward from a cylinder head of an engine main unit, swingably supported by a frame body with a cylinder axis tilting forward, and extends rearward above the cylinder head and a cylinder block is connected to an upper wall of the cylinder head; and a knock sensor is fastened, with a screw member, to a mounting boss formed on an upper wall of the cylinder block. A mounting boss 51 is formed on an upper wall 26a of a cylinder block 26 at such a position as to avoid overlapping with an intake pipe 35 as seen in a direction along a screw axis SC of a screw member 53.