PIEZO BASED ENERGY HARVESTING FOR E-LATCH SYSTEMS

• US 20160326779A1
• Filed: 07/11/2016
• Published: 11/10/2016
• Est. Priority Date: 11/21/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Papanikolaou, Kosta, Patel, Rajesh K.
• Granted Patent: US 10,422,166 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60J 5/00 Doors B60J10/00 takes precedence; window aspects B60J1/00 ; side board or tailgate structures for open load compartments B62D33/023
• CPC Class Codes: E05B 77/28 for anti-theft purposes, e.g. double-locking or super-locking
• CPC Class Codes: E05B 81/04 Electrical electrical circuits E05B81/54
• CPC Class Codes: E05B 81/14 operating on bolt detents, e.g. for unlatching the bolt
• CPC Class Codes: E05B 81/56 Control of actuators
• CPC Class Codes: E05B 81/76 Detection of handle operation; Detection of a user approaching a handle; Electrical switching actions performed by door handles
• CPC Class Codes: E05B 81/77 comprising sensors detecting the presence of the hand of a user
• CPC Class Codes: E05B 81/84 using manually operated generator means
• CPC Class Codes: E05B 81/86 using capacitors
• CPC Class Codes: E05B 85/10 Handles
• CPC Class Codes: H02N 2/186 Vibration harvesters
• CPC Class Codes: Y10T 292/1082 Motor

Abstract

A vehicle door includes an electrically-powered latch and a user input feature that can be actuated by a user to cause the electrically-powered latch to unlatch. An electrical energy storage device is operably connected to the electrically-powered latch, and a piezoelectric device is mounted to the door. The piezoelectric device can be manually actuated by a user to charge the electrical energy storage device, and electrical energy from the electrical energy storage device can be utilized to actuate the electrically-powered latch to thereby unlatch the latch. The user input feature may comprise a switch or sensor located adjacent a door handle/latch release on an inside and/or an outside of the vehicle door. The electrical energy storage device may comprise an emergency battery, capacitor, or other electrical device.

Claims

1. A vehicle door, comprising:

a door structure;

a handle fixed to the door structure;

an electrically-powered latch defining latched and unlatched states;

a user input feature comprising a sensor actuated by a user and causing the electrically-powered latch assembly to change from the latched state to the unlatched state in order to unlatch the door such that the door can be unlatched without movement of the handle relative to the door structure;

an electrical energy storage device that is operably connected to the electrically-powered latch;

a piezoelectric device operably connected to the electrical energy storage device such that the piezoelectric device is manually actuated by a user to charge the electrical energy storage device; and

wherein;

electrical energy from the electrical energy storage device is utilized to actuate the electrically-powered latch to thereby unlatch the electronically-powered latch without movement of the handle relative to the door structure.

2. The vehicle door of claim 1, wherein:

the sensor comprises a switch that is mounted to the vehicle door.

3. The vehicle door of claim 2, wherein:

the switch is mounted on the exterior side of the door.

4. The vehicle door of claim 3, wherein:

the door has an exterior surface portion;

the handle is disposed on the exterior side of the door with an inner side facing the exterior surface portion; and

the piezoelectric device is mounted on the inner side of the handle.

5. The vehicle door of claim 4, wherein:

the switch includes a movable switch member;

the piezoelectric device includes a bendable piezoelectric element that generates electrical energy upon bending, whereby the bendable piezoelectric element contacts the movable switch member and actuates the switch upon bending of the bendable piezoelectric element.

6. The vehicle door of claim 1, including:

an interior latch release including an interior piezoelectric device that can be manually actuated by a user from inside the vehicle to generate electrical power to actuate the electrically-powered latch to unlatch the door, and an interior sensor that can be actuated from inside the vehicle to unlatch the electrically-powered latch.

7. The vehicle door of claim 1 including:

an actuating member movably mounted to the interior side of the vehicle door; and

wherein;

the sensor comprises a switch mounted on the interior side of the door;

the piezoelectric device is configured to be manually actuated by movement of the actuating member.

8. The vehicle door of claim 7, wherein:

the switch includes a movable switch member;

the piezoelectric device includes a bendable element that generates electrical energy upon bending.

9. The vehicle door of claim 8, including:

a base mounted to the interior side of the vehicle door; and

wherein;

the actuating member movably engages the base;

the bendable element comprises a piezoelectric beam having a first end that is fixed to the base; and

upon movement of the actuating member, the actuating member engages and bends the bendable element and also engages and moves the movable switch member.

10. An electrically-powered latch system for vehicle doors, the electrically-powered latch system comprising:

a controller;

an electrically-powered latch including a movable catch member and a pawl that selectively engages the catch member in a closed position, and an electrically powered actuator that, upon receiving a signal from the controller, shifts the pawl between an engaged position wherein the electrically-powered latch remains in the latched position, and a released position wherein the electrically powered latch is in an unlatched configuration,

a piezoelectric device having a base and a piezoelectric element, a first portion fixed to the base and a second portion that moves relative to the first portion end when a force is applied to the piezoelectric element;

a sensor operably connected to the controller, the controller generating an unlatch signal that unlatches an electrically-powered latch without movement of a door handle upon actuation of the sensor; and

wherein;

the piezoelectric device is configured to generate electrical power that is utilized to power the electrically-powered latch.

11. The electrically-powered latch system of claim 10, wherein:

the piezoelectric element comprises a bendable piezoelectric element including an end that moves relative to the base.

12. The electrically-powered latch system of claim 10, wherein:

an exterior door handle having an inside surface that faces an exterior surface of a door when the exterior door handle is mounted on a vehicle door; and

wherein;

the sensor and the piezoelectric device are disposed on the inside surface of the handle.

13. The electrically-powered latch system of claim 12, wherein:

the sensor includes a movable switch member;

the bendable piezoelectric element engages and moves the movable switch member upon bending of the bendable piezoelectric element.

14. A vehicle door including the electrically-powered latch system of claim 10, wherein:

the vehicle door defines an exterior side and an interior side, and wherein the sensor is disposed on the interior side of the vehicle door.

15. The vehicle door of claim 14, wherein:

the vehicle door includes a movable actuating member that is configured to operably engage the first portion of the piezoelectric element and apply a force to the first portion of the piezoelectric element whereby a user can manually move the movable actuating member and cause the piezoelectric element to generate electrical power.

16. A vehicle door comprising:

a door structure and a handle mounted thereto;

an electrically-powered latch;

a controller;

a sensor;

primary and secondary batteries;

a piezoelectric element adjacent the sensor;

a movable actuating member that engages the piezoelectric element to generate electrical energy that charges the secondary battery, whereby the controller unlatches the electrically- powered latch in response to actuation of the sensor even if the handle does not move relative to the door structure.

17. The vehicle door of claim 16, wherein:

the vehicle door defines an outer side and an inner side;

the sensor and the piezoelectric element are disposed on the inner side of the vehicle door.

18. The vehicle door of claim 17, wherein:

the piezoelectric element is bendable;

the sensor comprises a switch;

the vehicle door includes a base and an actuating member movably engaging the base for reciprocating movement whereby reciprocating movement of the actuating member actuates the switch and bends the bendable piezoelectric element.

19. The vehicle door of claim 18, wherein:

the bendable piezoelectric element has a first end that is rigidly mounted to the base, and a second end that is substantially free, and wherein the actuating member engages the bendable piezoelectric element adjacent the second end.

20. The vehicle door of claim 16, wherein:

the controller is operably connected to the sensor, the primary and secondary batteries, the electrically-powered latch, and the piezoelectric element, and wherein;

the vehicle door includes an illuminated indicator adjacent the actuating member, and wherein the controller causes the illuminated indicator to generate a visible signal if the piezoelectric element needs to be actuated to charge the secondary battery due to a failure of the primary battery.