Switchable Double Tappet for Compact Valve Train
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing switchable valve train elements require separate guides and hydraulic medium supplies for each tappet, leading to complex construction, increased installation space, and assembly expenses when deactivating multiple gas-exchange valves.
Innovation Solution
A double tappet design that combines two supports for tappet push rods in a single housing, featuring a camshaft-side borehole with an inner element that moves axially and includes a coupling slide and lost-motion spring, allowing for simultaneous actuation of multiple gas-exchange valves with reduced housing diameter and simplified installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate guides and hydraulic medium supplies are provided for each tappet, then each tappet can be independently controlled, but the construction becomes complicated and installation space increases
Solution Approach 1:
The patent combines multiple tappet supports into a single integrated housing structure. The housing contains multiple boreholes for different tappets, and a single piston with multiple coupling slides can simultaneously control multiple valves. This merging approach maintains independent control capability while significantly reducing construction complexity and installation space requirements compared to separate tappet assemblies.
Solution Approach 2:
The single housing structure serves multiple functions: it provides supports for multiple tappet push rods, contains hydraulic medium supply channels for multiple pistons, and houses the camshaft interaction mechanism. This multi-functional design eliminates the need for separate guides and hydraulic supplies for each tappet, resolving the contradiction between adaptability and device complexity.
2Adaptability or versatility
If separate guides and hydraulic medium supplies are provided for each tappet, then each tappet can be independently controlled, but assembly expense increases
Solution Approach 1:
By merging multiple tappet supports into one housing assembly, the number of separate components requiring assembly is reduced. The housing is manufactured as a single piece containing all necessary boreholes, channels, and mounting features, which simplifies the assembly process and reduces labor costs compared to assembling multiple separate tappet units.
Solution Approach 2:
The universal housing design that accommodates multiple tappets with a single assembly process reduces manufacturing complexity. The integrated structure allows for standardized production methods and reduces the number of assembly steps required, thereby lowering assembly expenses while maintaining independent control of each tappet.
3Area of stationary object
If a double tappet design is used to reduce installation space, then housing diameter is reduced, but the mechanism becomes more complex
Solution Approach 1:
The design places multiple coupling slides and piston components within the confined space of a single housing. The nested arrangement allows multiple functional elements to occupy overlapping or adjacent spaces efficiently, reducing the overall housing diameter while maintaining the necessary mechanical functions for controlling multiple valves.
Solution Approach 2:
The patent utilizes three-dimensional space arrangement within the housing, positioning boreholes, pistons, and coupling slides in different spatial dimensions. This dimensional optimization allows the mechanism to fit within a smaller diameter housing by efficiently utilizing vertical and radial spaces rather than only horizontal arrangement.
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
The solution effectively eliminates the need for separate guides and hydraulic supplies, enabling efficient actuation of multiple valves with reduced space and assembly requirements, while maintaining a compact design.
Implementation Method 1
it is also provided to tension at least one lost-motion spring between an upper head of the inner element facing away from the lower head and a bottom side of a crossbar of the housing
Implementation Method 2
a tappet with a cylindrical housing that can be arranged so that it oscillates via its outer casing in a guide on the side of the internal combustion engine, and a borehole with an inner element, which can move axially relative to this borehole
Data Source
AI summary
A switchable double tappet (1) is provided, especially for a tappet-push rod valve train of an internal combustion engine, with a cylindrical housing (2), which is arranged so that it oscillates via its outer casing (3) in a guide (4) in the internal combustion engine side and which has a bore (5) on the camshaft side, in which an inner element (6) moves axially relative to this borehole, wherein, on one side, a cam contact surface (10) is intrinsic to this inner element on its end projecting past an edge (7) of the borehole (5) or lower head (9) running in the region of the edge (7) and also, on the other side, at least one coupling slide (11) is intrinsic in its interior in the decoupled case, and this coupling slide can be displaced partially for a coupled case in or under a respective catch surface (12) of the housing (2), wherein between an upper head (13) of the inner element (6) facing away from the lower head (9) and a lower side (14) of a crossbar (15) of the housing (2), at least one lost-motion spring (16) is tensioned and, in a borehole (17) of the housing (2) away from the camshaft, above the crossbar (15), there are two supports (18) lying next to one another, on each of which an end of a tappet push rod can be supported.