Fuel Pressure Sensor Connection Structure to Prevent Seal Rotation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The conventional connection structure for fuel pressure sensors experiences deterioration in sealing performance due to relative rotation between the abutting surface of the fuel rail and the contact surface of the fuel pressure sensor, which is caused by the sealing surface shifting during the application of torque.
Innovation Solution
A connection structure that includes a tubular attachment boss with a first screw portion and an abutting surface, an attachment portion with a contact surface and a bearing surface, and a nut with a second screw portion that presses the bearing surface against the abutting surface, preventing relative rotation and maintaining airtight sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the male screw is screwed until a specified torque is applied to maintain sealing performance, then the sealing surface is formed, but the sealing surface shifts in the rotation direction causing deterioration in sealing performance
Solution Approach 1:
A locking plate is introduced as an intermediary component between the male screw and the female screw. The locking plate has a locking protrusion that engages with a locking groove on the male screw, preventing relative rotation between the male screw and the female screw while allowing the sealing surface to maintain contact under applied torque
Solution Approach 2:
The locking protrusion and locking groove are pre-formed on the male screw and locking plate respectively, establishing the anti-rotation mechanism before the sealing surface is subjected to operational torque. This preliminary structural arrangement prevents sealing surface shift before it can occur
Data Source
Figure 1
Figure 2
Figure 3
AI summary
To provide a connection structure for a fuel pressure sensor that can prevents relative rotation between an abutting surface of a fuel rail and a sealing surface of a fuel pressure sensor, so as to suppress a deterioration in a sealing performance. A connection structure (1) for a fuel pressure sensor that connects a fuel pressure sensor (106) for detecting a pressure of a fuel to a fuel rail (103) in which the fuel to be supplied to an internal-combustion engine flows, includes a tubular attachment boss (10) that is formed in the fuel rail (103) and includes a male screw portion (13) and an abutting surface (14), an attachment portion (20) that is provided in a sensor body (106a) of the fuel pressure sensor (106), and includes a contact surface (22a) that abuts to the abutting surface (14) and a bearing surface (22b) provided behind the contact surface (22a), and a nut (30) including a female screw portion (33) that is screwed on the male screw portion (13) and a pressing portion (34) that presses the bearing surface (22b) to the abutting surface (14) by screwing the female screw portion (33) on the male screw portion (13).