Crimping device

A crimping device has for each crimper an anvil including a conductor anvil provided with a force sensor on which the force that arises in the conductor anvil during the crimping operation acts. The conductor anvil rests on a sensor body which in turn rests on a supporting part of the crimping device. The force sensor measures the force that is required to manufacture the conductor crimp, the quality of the crimped fastening being assessable by reference to the force curve generated by the force sensor.

BACKGROUND OF THE INVENTION

The present invention relates to a crimping device and a method of fastening a crimp contact to a wire, the wire conductor and wire insulation being fastenable to the crimp contact by means of a crimper and anvil, and the crimping force that thereby arises on the anvil being measurable by means of a force sensor.

U.S. Pat. No. 5,937,505 shows a crimping press by which an electrical contact can be fastened onto the end of a wire. A crimping punch and a crimping anvil together fasten the crimp contact to the wire end, the force arising in the crimping anvil being measurable by means of a force sensor.

A disadvantage of such devices is that the entire crimping force (conductor crimping force and insulation crimping force) is measured. It also is disadvantageous that the sensor is built into a wear part.

SUMMARY OF THE INVENTION

It is here that the present invention sets out to provide a remedy. The invention provides a solution for avoiding the disadvantages of the known device, and creating a device and a method that enable precise measurement of the crimping force.

The advantages achieved by means of the invention include that the force required to produce the conductor crimp is measurable. The force in the conductor anvil is transmitted to only one sensor. The pattern of the force during the crimping operation is measured and analyzed, the quality of the crimped connection being assessed by reference to the force curve. The force measurement according to the present invention meets the high requirements for quality assurance.

In the device according to the present invention, provided on each crimper is an anvil, the crimping force arising on a conductor anvil being measurable by means of a force sensor.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1shows a crimping press1according to the present invention comprising a first housing2on which a press motor3that drives a gear4is arranged. Provided on the output side of the gear is an eccentric device that converts the rotational motion of the motor3and gear4into a linear up-and-down motion that can be transferred to a press carriage5, the press carriage5being guided by means of guides6. Provided for the production of a crimped fastening between a crimp contact22(FIG. 2) and wire18, and arranged on the press carriage5, is an upper tool7with conductor crimper8, an insulation crimper9, and a cutter plunger10, the upper tool7working in conjunction with a lower tool11. The lower tool11comprises an anvil part15, a sensor part16, and a first supporting part17. The crimp contacts22to be processed are parts of a contact belt12that is advanced by a contact advancer13. An advancing motor14drives the contact advancer13.

FIG. 2shows the lower tool11with the anvil part15, the sensor part16, and the first supporting part17. Arranged on the anvil part15is a conductor anvil19and an insulation anvil21(FIG. 3). Arranged on the sensor part16is a force sensor20on which the force that arises in the conductor anvil19acts, the force sensor20in turn being supported on the first supporting part17. The first supporting part17itself is supported on the first housing2.

FIG. 3shows the crimper8,9, the conductor anvil19, the insulation anvil21, and a one of the crimp contacts22of the contact belt12before the crimping operation. The belted crimp contact22rests with its conductor crimp23on the conductor anvil19and with its insulation crimp24on the insulation anvil21. The wire18whose end is stripped of insulation is positioned above the crimp contact22, a free wire conductor25lying above the conductor crimp23, and a wire insulation26lying above the insulation crimp24. The conductor crimp23and insulation crimp24respectively are essentially V-shaped and open toward the top. The wire end is positioned in the conductor crimp23or insulation crimp24respectively by means of the lowering movement of the crimper8,9.

FIG. 4shows the crimper8,9, the conductor anvil19, and the insulation anvil21during crimping of the crimp contact22of the contact belt12, the conductor crimp23, and the insulation crimp24being thereby plastically deformed as shown inFIG. 5. The conductor crimp23embraces the strands of the wire conductor25, and the insulation crimp24embraces the wire insulation26. During the crimping operation, the crimp contact22is separated from the contact belt12.

FIG. 6shows the conductor anvil19with the force sensor20, on which the force that arises in the conductor anvil19during the crimping operation acts. The conductor anvil19rests on a sensor body27which in turn rests on the first supporting part17. Instead of the one force sensor20, several force sensors can be provided that measure the force that arises in the conductor anvil19. For example, wire strain gauges arranged on the conductor anvil19can measure the crimping force.

FIG. 7shows details of the force sensor20with the sensor body27. A disk-shaped piezoelectric element28that responds to the force of the conductor anvil19is arranged between a first disk29and a second disk30and electrically insulated from the sensor body27by means of a plastic ring31. The sensor body27and the first disk29are made of one piece, the second disk30being threaded onto the sensor body27. Conducting pathways integrated in a foil32conduct the signal of the piezoelectric element28to a plug connector33.

In a further exemplary embodiment, the sensor body27is executed as a threaded screw with screw head, and the first disk29is executed as a loose disk with drilled hole. The threaded screw penetrates the drilled hole and the piezoelectric element28. The second disk30is screwed onto the end of the threaded screw with its internal thread and then the two disks29,30are screwed by means of the screw head until the required pretension of the piezoelectric element28is attained.