Apparatus and method of measuring the stress on a work machine

• US 6,314,818 B1
• Filed: 03/29/1999
• Issued: 11/13/2001
• Est. Priority Date: 03/29/1999
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Mandon, Stephane L.
• Primary Examiner(s): Fuller, Benjamin R.
• Assistant Examiner(s): DAVIS, OCTAVIA L
• Application Number:
  US09/280,162
• Time in Patent Office: 960 Days
• Field of Search: 737/81, 738/624.9, 738/625.4, 738/626.4, 701/862.52, 913/61, 603/27
• US Class Current: 73/781
• CPC Class Codes: E02F 3/34 with bucket-arms , i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms with a single arm E02F3/283 directly pivoted on the frames of tractors or self-propelled machines
• CPC Class Codes: E02F 9/24 Safety devices , e.g. for preventing overload E02F9/226 takes precedence
• CPC Class Codes: E02F 9/26 Indicating devices E02F5/145 takes precedence
• CPC Class Codes: G01L 5/0061 Force sensors associated with industrial machines or actuators for the specific machine or actuator involved see relevant class, e.g. F01, F04, F16, B66, E21

Abstract

An apparatus and method of measuring the stress on a work machine is disclosed. A work machine includes a frame, a plurality of ground engaging devices, an operator compartment, an implement having a linkage, an engine, and a stress measurement control system. The stress measurement control system includes a strain gauge sensor, a memory, an electronic controller, and an operator interface. The strain gauge sensor assembly is mounted to the frame or the implement and provides a stress signal indicative of the stress acting upon the frame or the implement. The memory stores a stress signal value and stress limit value. The electronic controller receives the stress signal and the stress limit value, determines whether the stress signal is greater than the stress limit value, and responsively stores the stress signal value in the memory and provides an associated message. The operator interface receives the associated message and provides it to the operator in the operator compartment.

Claims

1. A work machine controlled by an operator and acting upon a load through a plurality of work cycles, comprising:

a frame;

a plurality of ground engaging devices supporting the frame;

an operator compartment supported by the ground engaging devices;

an implement having a linkage for connecting the implement to the frame;

an engine coupled to the ground engaging devices; and

a stress measurement control system, including;

a strain gauge sensor assembly mounted to at least one of the frame and implement and providing a stress signal having a stress signal value indicative of a stress acting upon at least one of the frame and implement;

a memory storing at least one stress signal value and at least one pre-determined stress limit value;

an electronic controller associated with the memory and receiving the at least one stress signal and the at least one pre-determined stress limit value, determining whether the stress signal value is greater than the pre-determined stress limit value and responsively providing an associated message; and

an operator interface receiving the associated message and providing the associated message to the operator in the operator compartment.

2. The work machine of claim 1, wherein the associated message is provided to the operator as an audible message.

3. The work machine of claim 1, wherein the associated message is provided to the operator as a visual message.

4. The work machine of claim 3, wherein the visual message is a warning light.

5. The work machine of claim 1, wherein the frame includes a cross member and the strain gauge assembly is tack welded to the cross member of the frame.

6. The work machine of claim 1, wherein the frame has a weldjoint and the strain gauge assembly is tack welded proximate the weldjoint.

7. A method of measuring a stress on a work machine controlled by an operator and acting upon a load through a plurality of work cycles, comprising the steps of:

mounting a strain gauge sensor assembly to at least one of a frame and implement;

providing a stress signal having a stress signal value indicative of a stress acting upon at least one of the frame and implement;

storing at least one stress signal value and at least one pre-determined stress limit value;

receiving the at least one stress signal and the at least one pre-determined stress limit value;

determining whether the stress signal value is greater than the pre-determined stress limit value and responsively providing an associated message; and

receiving the associated message and providing the associated message to the operator in the operator compartment.

8. The method of claim 7, including the step of providing the associated message to the operator as an audible message.

9. The method of claim 7, including the step of providing the associated message to the operator as a visual message.

10. The method of claim 7, including the step of tack welding the strain gauge assembly to a cross member of the frame.

11. The method of claim 10, including the step of tack welding the strain gauge assembly proximate the weldjoint.

12. A work machine controlled by an operator and acting upon a load through a plurality of work cycles, comprising:

a frame having at least one cross member subject to stress that changes depending on a work cycle and load, the cross member being connected to the frame by a weldjoint;

an implement engaging the load and having a linkage for connecting the implement to the frame;

a plurality of ground engaging devices supporting the frame;

an operator compartment supported by the ground engaging devices;

an engine coupled to the ground engaging devices; and

a stress measurement control system, including;

a strain gauge sensor assembly tack welded to the cross member proximate the weldjoint and providing a stress signal having a stress signal value indicative of the stress acting upon the frame;

a memory storing at least one stress signal value and at least one pre-determined stress limit value;

a controller associated with the memory and receiving the at least one stress signal and the at least one pre-determined stress limit value, determining whether the stress signal value is greater than the pre-determined stress limit value and responsively providing an associated message; and

an operator interface receiving the associated message and providing the associated message to the operator in the operator compartment.