Engine Device Oblique Screw Hole Case Space Stiffness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing engine power equipment requires additional space for a lower support structure, which either reduces the internal case space or necessitates a larger case, while maintaining support stiffness is a challenge.
Innovation Solution
The engine device incorporates a crankcase with a screw hole formed obliquely at the bottom corner, allowing the fastening bolt and attachment bracket to be displaced downward, thereby enlarging the case space without compromising support stiffness, and includes a mounting axial member with rubber bushings to absorb vibrations and distribute loads linearly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If the attachment bracket is positioned at the conventional location on the crankcase, then the support stiffness is maintained, but the internal case space is reduced
Solution Approach 1:
The screw hole is formed obliquely inward from the bottom corner of the crankcase rather than horizontally from the side, changing the directional approach to access the attachment bracket mounting location. This oblique angulation allows the fastening bolt to engage the attachment bracket while positioning it lower and more laterally, thereby enlarging the internal case space without compromising support stiffness
2Volume of stationary object
If the screw hole is formed horizontally from the side of the crankcase, then the attachment bracket can be easily fastened, but the internal case space is reduced and the screw hole may interfere with other components
Solution Approach 1:
The screw hole is formed obliquely inward from the bottom corner of the crankcase rather than horizontally from the side, changing the directional approach to access the attachment bracket mounting location. This oblique angulation allows the fastening bolt to engage the attachment bracket while positioning it lower and more laterally, thereby enlarging the internal case space without compromising support stiffness
Solution Approach 2:
The screw hole is positioned asymmetrically at the bottom corner of the crankcase rather than at the center or symmetric locations. This asymmetric positioning allows the fastening bolt to engage the attachment bracket at an optimal angle while maximizing the utilization of available space in the crankcase, thereby enlarging the internal case space without compromising support stiffness
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 allows for an enlarged internal case space without lowering support stiffness, enabling increased muffler size and improved exhaust gas purification performance without affecting the muffling effect.
Implementation Method 1
the attachment bracket is attached to the mounting part via a mounting axial member penetrating horizontally through an attachment hole provided in the attachment bracket and a support hole provided in the mounting part, and the mounting axial member at least partially overlaps with the fastening bolt when viewed in an axial direction of the fastening bolt
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is an engine device that can enlarge a space inside a case without lowering support stiffness. An engine (2) is attached to a case (11) via support parts (81, 82). A rear lower portion support part (82), which is one of the support parts, includes an attachment rib (11b)as a mounting part provided in the case (11) and an attachment bracket (91) fastened to a bottom of a crankcase (46) by a fastening bolt (90) and attached to the attachment rib (11b). The fastening bolt (90) penetrates through a through hole (92a) provided in the attachment bracket (91) and is screwed into a screw hole (46e) formed obliquely inward at a corner of the bottom of the crankcase (46).