Remotely Mounted Actuator Isolating Valve Pin Control from Manifold Heat
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Solution Overview
Problem
Existing injection molding systems face challenges in efficiently controlling the valve gate operation due to heat exposure from the heated manifold, leading to potential mechanical issues and reduced precision in fluid flow control.
Innovation Solution
The system incorporates an electrically powered actuator with a rotary to linear converter, featuring a rigid elongated shaft and a torque increasing or rotational speed reducing device, mounted in a position isolated from heat exposure, along with a position sensor for precise control of the valve pin's movement, using a gear reduction device and couplings that accommodate thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the actuator is mounted close to the valve pin for direct control, then control precision is improved, but heat exposure from the heated manifold increases causing mechanical issues
Solution Approach 1:
The system is divided into separate functional modules: the actuator is mounted remotely on the injection molding machine platen, while the valve pin remains integrated with the heated manifold. An elongated shaft connects these separated components, allowing the actuator to control the valve pin without being exposed to manifold heat, thus resolving the contradiction between control precision and heat exposure.
Solution Approach 2:
The elongated shaft serves as an intermediary element that transmits rotational motion from the remotely mounted actuator to the valve pin. This intermediary allows the actuator to be positioned away from heat sources while maintaining effective control of the valve pin, eliminating direct heat exposure while preserving control functionality.
2Object-affected harmful factors
If an elongated shaft is used to connect the remotely mounted actuator to the valve pin, then heat exposure is reduced, but mechanical stress and potential precision loss increase
Solution Approach 1:
The system incorporates dynamic compensation mechanisms including flexible couplings that accommodate thermal expansion and contraction of the heated manifold. These dynamic elements allow the elongated shaft to maintain reliable mechanical connection while absorbing thermal stresses, preventing precision loss and mechanical failure despite the extended connection length.
Solution Approach 2:
The design accounts for thermal parameter changes by using materials and coupling mechanisms that can tolerate thermal expansion. The flexible couplings and precision bearings are selected to maintain mechanical integrity across temperature variations, ensuring the elongated shaft remains reliable despite exposure to thermal environments.
3Speed
If a rigid elongated shaft is used for rotation transmission, then rotational motion transmission is improved, but accommodation of thermal expansion becomes difficult
Solution Approach 1:
The shaft assembly incorporates localized flexible elements at specific positions (couplings and bearings) while maintaining rigid sections for efficient rotational transmission. This local differentiation allows the system to transmit rotation effectively while accommodating thermal expansion at the flexible coupling points, resolving the contradiction between rigidity and adaptability.
Solution Approach 2:
The shaft system uses composite construction combining rigid shaft sections for rotational transmission with flexible coupling sections that accommodate thermal expansion. This composite approach allows simultaneous achievement of efficient motion transmission and thermal adaptability through the integration of different material properties in a single assembly.
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 ensures precise control of the valve gate operation, reduces mechanical stress, and maintains system accuracy by isolating the actuator from heat exposure, thereby enhancing the efficiency and reliability of fluid flow management during the injection molding process.
Implementation Method 1
The transmission includes a variable-length connecting rod
Implementation Method 2
a torque increasing or rotational speed reducing device
Implementation Method 3
an elongated shaft 20 comprised of a rigid material such as steel that is interconnected to, extends from and is rotatably driven by the gearhead
Implementation Method 4
a device that converts the rotation of the elongated shaft to linearly driven motion referred to as a rotary to linear converter 40
Implementation Method 5
If the rotary to linear converter is attached to the heated manifold, the couplings must accommodate thermal expansion both side to side and axially
Implementation Method 6
The rotary to linear converter device may include a cooling circuit
Implementation Method 7
heat is convected from the housing 40h to the TCP thus cooling the moving or driven members of the converter assembly 40
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
An injection molding apparatus comprising a valve (50) comprised of: an actuator (200) having a rotor (12) interconnected to a distal end (22) of an elongated shaft (20) adapted to drivably transmit rotational motion (R1) of the rotor to rotational motion (R2) of the shaft (20), the shaft (20) being interconnected at a proximal end (24) to a converter (40) adapted to transmit rotational motion (R2) of the shaft (20) directly to driven linear motion (A) of a valve pin (100), the shaft (20) having a length or configuration (LC) selected such that the actuator (200) is mountable on the apparatus in a position or disposition that is isolated or insulated from significant or substantial exposure to or transmission of heat from a heated manifold (60).