Parking Lock Manual Release Lever Inversion

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Solution Overview

Problem

The durability of the urging member in manual release mechanisms for parking lock systems is compromised due to self-weight and inertia forces, leading to increased operational forces required to switch the system from a locked to an unlocked state.

Innovation Solution

The manual release device incorporates an idle motion mechanism with a lever and urging member, where the lever's distal end is positioned below its turning center, and the urging member is arranged to urge the lever towards the vehicle front side, reducing load and inertia inputs, and aligning the tangential direction of the lever's turn with the cable's movement at maximum torque, to efficiently transmit operational forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the urging member is provided to urge the lever of the idle motion mechanism, then the lever can be returned to the normal position, but the self weight of the lever increases the load on the urging member and reduces its durability

Engineering Contradiction:

Improvedurability of urging memberVSAvoidload on urging member

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The patent inverts the conventional lever configuration by positioning the distal end below the turning center instead of above it. This inversion changes the direction of the lever's self-weight relative to the turning center, transforming the self-weight from a load that increases urging member stress to a force that reduces the operational load on the urging member, thereby improving durability

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the geometric parameter of the lever configuration by positioning the distal end below the turning center. This parameter change alters the moment arm configuration, causing the lever's self-weight to generate a moment that opposes the operational force rather than adding to it, thereby reducing the total load on the urging member

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If the lever is positioned with distal end above turning center, then the lever can be operated easily, but the inertia force of the lever increases the load on the urging member during vehicle deceleration

Engineering Contradiction:

Improvelever operationVSAvoidinertia force on urging member

Core Design Contradiction:

Ease of operationVSForce

Solution Approach 1:

By inverting the lever position to place the distal end below the turning center, the patent changes how inertia forces act during vehicle deceleration. The inverted configuration causes the inertia force to act in a direction that reduces the load on the urging member, whereas the conventional configuration would increase the load

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts the potentially harmful effect of the lever's self-weight and inertia forces into a beneficial effect. By inverting the lever configuration, the self-weight and inertia forces that would normally increase the load on the urging member are transformed into forces that reduce the operational load, thereby improving durability without compromising operation

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 enhances the durability of the urging member, reduces the operational force needed to switch the parking lock mechanism, and prevents the need for increased cable load capacity, thereby improving the overall design and functionality of the manual release device.

Implementation Method 1

reduce a load input to the urging member due to the self weight of the lever

Methodology Applied

Scientific EffectSelf weight: Gravitation

Implementation Method 2

suppress input of the inertia force of the lever to the urging member

Methodology Applied

Scientific EffectInertia force: Inertia

Data Source

PatentUS10166955B2Manual release device for parking lock mechanism

Publication Date: 2019.01.01 TOYOTA JIDOSHA KK

AI summary

A manual release device for a parking lock mechanism includes an operating lever, a cable and an idle motion mechanism. The idle motion mechanism includes a body portion, a lever provided on the body portion, a helical compression spring, and a contact portion provided on the shaft. The cable is coupled to the lever. A distal end of the lever is arranged below a turning center of the lever. The parking lock mechanism is configured, when the parking lock mechanism is in a locked state, to be switched into an unlocked state as the body portion contacts the contact portion to cause the shaft to turn when the lever is turned against an urging force of the urging member as a result of operation of the operating lever to cause the body portion to turn from the normal position to the actuated position.