Transport Refrigeration Electronics Housing With External Voltage Test Sockets

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Solution Overview

Problem

Maintenance and repair of electronic units in transport refrigeration machines of commercial vehicles are complex and risky due to high voltages, requiring safe and efficient methods to ensure technician safety.

Innovation Solution

Incorporation of accessible test sockets or plugs outside the electronics housing for voltage measurement using a two-pole voltage tester, along with a battery connection and cooling circuit to manage high voltages safely.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the electronics housing is opened for maintenance and repair, then access to electronic components is improved, but the risk of electric shock increases due to high voltages

Engineering Contradiction:
ImproveAccess to electronic componentsVSAvoidRisk of electric shock
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by providing test sockets that allow voltage verification before opening the electronics housing. Technicians can use a two-pole voltage tester to check for voltage presence through the test sockets, ensuring safe conditions before accessing internal components. This preliminary safety check prevents electric shock by allowing technicians to confirm de-energized state before opening the housing.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If voltage measurement is performed inside the electronics housing, then accurate voltage detection is improved, but the complexity and risk of maintenance procedures increases

Engineering Contradiction:
ImproveVoltage detection accuracyVSAvoidMaintenance procedure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the voltage measurement function from the internal electronics to external test sockets. The test sockets are positioned on the housing exterior, allowing voltage measurement without opening the housing or exposing technicians to internal high-voltage components. This extraction simplifies the maintenance procedure while maintaining measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the electronics housing is designed with sealed enclosure for protection, then protection of electronic components is improved, but accessibility for maintenance and testing deteriorates

Engineering Contradiction:
ImproveProtection of electronic componentsVSAvoidAccessibility for maintenance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The test sockets serve multiple functions: they provide voltage measurement capability, maintain the sealed protection of the electronics housing, and enable external access for diagnostics. The same housing structure that protects internal components also incorporates external test access points, achieving both protection and accessibility simultaneously.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Facilitates safe, quick, and cost-effective maintenance by allowing voltage testing without opening the housing, reducing the risk of electric shock and simplifying connections.

Implementation Method 1

In the evaporator, a refrigerant, previously expanded through a throttle, is evaporated. The refrigerant absorbs heat from the air in the cargo space via a heat exchanger surface.

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

The refrigerant is then compressed and condensed in a condenser.

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

The refrigerant is then compressed and condensed in a condenser. The condenser also has a heat exchanger surface, allowing the heat released during condensation of the refrigerant to be dissipated to the environment.

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

a throttle upstream of the evaporator for expanding the refrigerant condensed in the condenser

Methodology Applied
Scientific EffectThrottling: Pressure Drop

Data Source

PatentEP4488082B1Transport refrigeration machine having an electronics unit and commercial vehicle having a transport refrigeration machine
Publication Date: 2025.08.27 SCHMITZ CARGOBULL AG
  • EP4488082B1 patent drawingFigure 1
  • EP4488082B1 patent drawingFigure 2
  • EP4488082B1 patent drawingFigure 3

AI summary

Described and illustrated is a transport refrigeration machine (12) for cooling a box body (5) of a commercial vehicle (1), in particular a truck, a trailer or a semi-trailer, comprising a refrigeration circuit (14) for circulating a refrigerant and an electronic unit (17) for operating the refrigeration circuit (14), wherein the refrigeration circuit (14) comprises at least one evaporator for evaporating the refrigerant, a compressor for compressing the refrigerant evaporated in the evaporator, a condenser for condensing the refrigerant compressed in the compressor and an expansion valve for expanding the refrigerant condensed in the condenser, wherein the electronic unit (17) is housed in an electronics enclosure (14) and wherein the electronics enclosure (17) comprises at least a part of at least one electrical circuit (32).In order to enable maintenance and/or repair work on the electronic unit in the electronic housing to be carried out safely, reliably, quickly and cost-effectively, the electronic housing (17) is provided to have at least two externally accessible measuring sockets (24) or measuring plugs electrically connected to at least one part of the at least one circuit (32) for measuring the voltage of the at least one circuit (32) via a two-pole voltage tester connectable to the measuring sockets (24) or measuring plugs.