Automatic Transmission Valve Body Channel Depth for Vibration Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control valve body structures in automatic transmissions experience vibration and noise due to pressure fluctuations caused by vortex rings formed in oil passages, which are not adequately suppressed by conventional anti-vibration measures.
Innovation Solution
A control valve body structure where the depth of the channel facing the orifice is set to be shallower than the upstream channel depth, with the depth of the channel area facing the orifice and the orifice diameter satisfying a relationship of h≤3d, preventing continuous vortex ring formation and pressure fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the channel depth facing the orifice is increased to suppress pressure fluctuations, then the vibration suppression improves, but the manufacturing complexity and machining cost increase
Solution Approach 1:
The patent applies local quality by creating a shallower channel section (second channel section) specifically in the region facing the orifice where pressure fluctuations occur, while maintaining the normal channel depth in other regions. This localized modification targets the vibration problem area without unnecessarily complicating the entire channel structure, thereby suppressing vibration and noise while controlling manufacturing complexity.
2Object-generated harmful factors
If the channel depth is made shallower to prevent vortex ring formation, then the noise generation is reduced, but the oil passage flow capacity may be affected
Solution Approach 1:
The shallower channel depth is applied locally only in the region facing the orifice where vortex rings form and cause noise, while other channel regions maintain their original depth to preserve overall flow capacity. This selective approach reduces noise generation without significantly compromising the oil passage's total flow capability.
Solution Approach 2:
The patent converts the potential harm of reduced flow capacity in the shallower section into a benefit by using the channel depth variation to disrupt vortex ring formation. The geometric modification that initially might seem to restrict flow actually prevents harmful pressure fluctuations and noise, transforming a potential disadvantage into a noise suppression mechanism.
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 vibration of the separate plate adjacent to the orifice and the resulting noise, without the need for extensive machining, thereby reducing manufacturing costs and noise generation.
Implementation Method 1
a vortex ring S caused by this flow velocity difference appears in the working fluid. As shown in FIG. 6(b), since the orifice 121 is a small circular hole viewed from above, the vortex ring S formed in the oil passage 102 is formed cylindrically so as to surround the center axis X of the orifice 121.
Implementation Method 2
a pressure of a segment Sd between contiguous vortex rings S and S becomes higher than that of a core Sc of the vortex ring S. Because of this, when the working fluid in the oil passage 101 is pushed out to the oil passage 102 through the orifice 121, fluctuation in up-and-down directions in the pressure adjacent to the orifice 121 in the oil passage 102 repeatedly occurs due to the vortex ring S continuously appearing.
Data Source
AI summary
Structure of control valve body of automatic transmission has valve body enclosures having channels on opposing surfaces thereof; a separate plate sandwiched between the valve body enclosures for defining oil passages on both sides of the separate plate; and an orifice provided at the separate plate. The oil passages on both sides of the separate plate, which are upstream and downstream side oil passages located on upstream and downstream sides of the separate plate, communicate with each other through the orifice. Depth h, in a part facing to the orifice, of the channel corresponding to the downstream side oil passage is set to be shallower than depth of the channel corresponding to the upstream side oil passage, and the depth h of the channel in the part facing to the orifice and a diameter d of the orifice are set so as to satisfy relationship of h≤3d.