Vane Rotor Lock Pin Radial Size Reduction
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Solution Overview
Problem
The existing valve timing control devices for internal combustion engines face a challenge in maintaining the radial direction size of the large diameter portion while accommodating a lock member, leading to increased rigidity requirements that result in larger dimensions.
Innovation Solution
A vane rotor with alternating small and large diameter portions, where the large diameter portion extends circumferentially to cover the lock hole and includes a first vane protruding radially outward, allowing the lock member to be positioned close to the large diameter portion's inner side, thereby reducing the radial size of the large diameter portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the lock member is provided at the large diameter portion to ensure rigidity, then the structural strength is improved, but the radial direction size of the large diameter portion increases
Solution Approach 1:
The lock member is repositioned from the traditional location at the large diameter portion to the small diameter portion of the vane rotor. This spatial relocation in the radial dimension allows the large diameter portion to maintain its structural integrity and rigidity while reducing its radial direction size, as the locking function is now fulfilled by the small diameter portion area.
2Area of moving object
If the lock member is moved closer to the outer periphery of the large diameter portion, then the pressure receiving area of the vane is increased, but the thickness around the accommodation hole decreases
Solution Approach 1:
The lock member and its accommodation hole are relocated to the small diameter portion, which creates sufficient radial thickness in that region to accommodate the lock member structure. This allows the large diameter portion to extend its pressure receiving area to the outer periphery without compromising the thickness requirement around the accommodation hole, as the locking mechanism is now positioned in the radially inner small diameter portion.
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 effectively suppresses the increase in radial direction size of the large diameter portion, reduces its size, and enhances the response of the valve timing control by increasing the pressure receiving area of the vane, leading to improved stability and reduced weight of the device.
Implementation Method 1
by controlling hydraulic pressures of these retard and advance working chambers, a rotation position of the vane rotor relative to the housing is changed
Data Source
AI summary
Lock pin (71) is disposed movably in axial direction in accommodation hole (70) formed at vane rotor (12). Top end portion of lock pin (71) is fitted into lock hole (23) provided at housing (11), then relative rotation position of vane rotor (12) is restrained at predetermined lock position. Vane rotor (12) is provided with small diameter portion (84) and large diameter portion (85) which are formed alternately in circumferential direction. Large diameter portion (85) extends in circumferential direction so as to cover lock hole (23). First vane (36A) protrudes from outer periphery of large diameter portion (85) to radially outer side. At least a part of lock pin (71) and at least a part of accommodation hole (70) overlap with large diameter portion (85), and are located at position that overlaps with area (86) formed by elongating first vane (36A) to radially inner side.