Patent Description:
Wires are terminated using a variety of methods, such as, crimping, soldering or welding. For example, electrical terminals are typically crimped onto wires by a crimping apparatus to form a lead. The crimping apparatus has crimp tooling made up of a first part mounted to a base for supporting the electrical terminal and a second part mounted to a ram that is movable toward and away from the base for effecting the crimp. In operation, the terminal is placed on the first part of the crimp tooling and an end of a wire is inserted into the ferrule or barrel of the terminal. The ram is caused to move toward the base through a crimp stroke, thereby crimping the terminal onto the wire. A wire terminating apparatus (on which the preamble of claim <NUM> is based) is disclosed in patent <CIT>. The apparatus includes crimp tooling defining a crimp zone. An ultrasonic module transmits acoustic signals through a crimped terminal and a wire onto which it has been crimped. Reflected acoustic signals are analysed to check that sufficient crimp quality has been achieved.

It would, therefore, be beneficial to provide a wire termination monitoring system and method which can be used to monitor different terminations of wires. In particular, it would be beneficial to provide a wire termination monitoring system and method which does not solely measure force or dimensions, but monitors the thermal characteristics of the termination.

According to the invention there is provided a wire terminating apparatus according to claim <NUM>. An embodiment is directed to a crimping apparatus which allows for determining the quality of a crimp. The apparatus includes an applicator which has an anvil and a crimp tool which is movable relative to the anvil, The anvil and a crimp tool define a crimping zone of the apparatus. A thermal sensor is mounted on the crimping apparatus proximate the applicator. The thermal sensor monitors the thermal properties of the crimp made by the applicator to determine if the crimp is defective.

Herein disclosed is a method of determining the quality of a termination of a wire or terminal. The method includes: terminating the wire; monitoring the thermal properties of the termination with one or more thermal sensors; and comparing the monitored thermal properties to stored thermal properties to determine if the termination is defective. If the termination is defective, the termination is discarded.

A device (<FIG>) and method of monitoring the crimping processes (<FIG> and <NUM>) for the purpose of determining crimp quality by using thermal characteristics and signatures is shown. However, the use of the crimping machine is meant to be illustrative and not limiting. The use of thermal data and analysis, as described below, to monitor the termination of wires, conductors or terminals has other uses beyond just crimp related applications.

<FIG> is a perspective view of a crimping machine <NUM> having an applicator <NUM>. The crimping machine <NUM> is illustrated as a terminal crimping machine used for crimping terminals to wires, however, other types of machines may be used, such as an insulation displacement connector (IDC) machine, a welding machine, and the like, that attach connectors to wires using processes other than crimping. Alternatively, the crimping machine <NUM> may be another type of crimping machine such as a lead frame machine.

The applicator <NUM> is coupled to the crimping machine <NUM>. The applicator <NUM> may be removed and replaced with a different applicator, such as when the applicator <NUM> is worn or damaged or when an applicator having a different configuration is desired. The applicator <NUM> has a terminating zone or crimping zone <NUM> and includes a crimper or crimp tooling <NUM> and an anvil <NUM> as the mechanical tooling for crimping electrical connectors or terminals <NUM> to an end of a wire <NUM> in the crimping zone <NUM>. The anvil <NUM> is a stationary component of the applicator <NUM>, and the crimp tooling <NUM> represents a movable component.

One or more thermal sensors <NUM> are mounted to the crimping machine <NUM>. The thermal sensors <NUM> may be mounted at various locations in or proximate to the crimping zone <NUM>. The thermal sensors <NUM> may be removably mounted by a removable device, such as, but not limited to, a magnet (not shown). Alternatively, the thermal sensors <NUM> may be held in place by using mechanical fasteners, latches, adhesives, and the like. While the thermal sensors <NUM> are shown circular members, the thermal sensors <NUM> may have other shapes.

In an exemplary embodiment, each of the thermal sensors <NUM> are positioned to have a field of view that includes the crimping zone <NUM>. The thermal sensors <NUM> are positioned to acquire the thermal characteristics, in the form of discrete thermal data, of the terminal <NUM> and/or the wire <NUM> in the crimping zone <NUM>. In an exemplary embodiment, at least one of the thermal sensor <NUM> is positioned in-line with a longitudinal axis <NUM> of the anvil <NUM> and a barrel <NUM> of the terminal <NUM>. This allows the thermal sensor <NUM> to directly sense and collect the thermal data from the thermal energy that is emitted directly from the terminal <NUM> and/or the wire <NUM>. In an alternate embodiment, one or more of the thermal sensors <NUM> may be positioned out-of-line or off-center from the axis <NUM>. If one or more of the sensors <NUM> are positioned out-of-line or off-center from the axis <NUM>, those thermal sensors <NUM> may collect thermal energy that is transferred through the terminal <NUM> to the wire <NUM> or to another object and/or those thermal sensors <NUM> may collect thermal energy which is reflected off the terminal <NUM> and/or the wire <NUM>.

For example, positioning bodies or objects around the terminal <NUM> and/or wire <NUM> which are configured to intentionally reflect or direct thermal energy from the terminal <NUM> and/or the wire <NUM> being sensed would allow a thermal sensor <NUM> to be out-of-line or off-center from the terminal <NUM> and read thermal data that is reflected from the surrounding bodies or objects. Construction of these surrounding bodies could be done with materials of known emissivity to enhance the reflected imaging of the thermal characteristics of the terminal <NUM> and/or the wire <NUM> being terminated. This would allow the ability to thermally "sense" areas that would not be easy viewed or to view more surface area of the terminal <NUM> and/or the wire <NUM> with fewer sensors.

As previously stated, the thermal data collected by the one or more thermal sensors <NUM> may be one or a combination of three distinct components of energy. The first is thermal energy emitted directly from the terminal <NUM> and/or the wire <NUM>. The second is thermal energy that is transferred through the object (heat from somewhere else that passes through) such as from the terminal <NUM> to the wire <NUM>. The third is thermal energy reflected off the terminal <NUM> and/or the wire <NUM>.

In one exemplary embodiment, the thermal data is captured by a plurality of sensors <NUM> arranged in a matrix (such as a charge coupled device network) which allows the thermal data to be captured and arranged in rows and columns - similar to how pixels of data describe a visual image collected with a conventional visual energy camera. For example, one thermal sensor may be positioned in-line with the longitudinal axis of the of the terminal, while other thermal sensors of the matrix may be positioned out-of-line or off-center from the axis. Due to the number of data points, techniques, such as but not limited to, an adapted convolution neural network, are used to extract features from these matrices of data to analyze the process of a crimp before, during and after the crimp has been formed. These features are apparent in particular regions of interest on the terminal <NUM> and/or the wire <NUM> and form the basis of categorization of the termination.

The characteristics and signatures of the thermal data collect may include, but are not limited to: i) area heating; ii) heat transfer times; iii) heat transfer patterns; iv) temperature delta v) physical characteristics and variations identified through thermal properties.

In addition, the thermal data is collected at various times, which results in a time series of images. Using analysis techniques, such as, but not limited to artificial intelligence, the time varying data is analyzed.

In various illustrative examples, the thermal sensors <NUM> have the ability to collect absolute temperatures. Absolute temperatures provide the potential for not just analyzing "relative" regions of interest but potentially distinct mechanical characteristics of the termination.

A display device <NUM> may be communicatively coupled to the thermal sensor <NUM> and configured to display the thermal characteristics acquired by the thermal sensor <NUM>. The display device <NUM> may be integrated into a host controller or processor of the crimping machine <NUM> itself or may be a separate controller or processor <NUM>, such as a desktop computer, a laptop computer, a tablet computer, a monitor, a projector, and the like. Optionally, the display device <NUM> may be a crimp quality monitor (CQM) device. The controller <NUM> and/or display device <NUM> may be coupled to the thermal sensor <NUM> through a cable or the like. Alternatively, the controller <NUM> and/or display device <NUM> may communicate wirelessly through induction, radio frequency waves, Wi-Fi, and the like to transmit data between the thermal sensor <NUM> and the controller <NUM> and/or display device <NUM>.

The controller <NUM> and/or display device may include a storage or memory device <NUM> such as, but not limited to, a hard disk drive, RAM, ROM, and/or another internal data storage device. The memory device <NUM> may be configured to store data acquired by the thermal sensor <NUM>. Such data may be used for subsequent quality reporting purposes.

In various examples, the crimping machine <NUM> may include additional sensors <NUM>, such as, but not limited to, a force sensor or a linear sensor to provide additional data with respect to the quality of the crimp.

During a crimping operation, the crimp tooling <NUM> is driven initially towards the stationary anvil <NUM> and finally away from the anvil <NUM>, as represented by <NUM> in <FIG> illustrates the method of determining the quality of a termination <NUM>. Thus, the crimp stroke has both a downward component and an upward component. The crimping of the terminal <NUM> to the wire <NUM> occurs during the downward component of the crimp stroke. The crimp tooling <NUM> engages the terminal <NUM> and crimps the terminal <NUM> onto the wire <NUM> by compressing the terminal <NUM> between the crimp tooling <NUM> and the anvil <NUM>. As this occurs, thermal energy or heat is produced in the terminals and the wires within and proximate to the crimp.

As previously stated, the thermal sensors <NUM>, either directly from thermal sensors <NUM> positioned in line with the axis <NUM> or indirectly from thermal sensors positioned out-of-line or off-center from the axis <NUM>, may acquire temperature measurements/data at designated intervals or continuously of the terminals <NUM> and the end of the wire <NUM> positioned in the crimping zone <NUM>, as represented by <NUM> in <FIG>. The collected temperature measurements/data is transmitted to the display device <NUM>, the controller <NUM> or the memory device <NUM>, either on the crimping machine <NUM> or at an external location from the crimping machine <NUM>. The temperature measurements/data transmitted by the thermal sensor <NUM> is used by an operator of the crimping machine <NUM> to be able to determine if the termination of the wire meets appropriate standards to provide the desired electrical and mechanical connection. The terms "operator" is used herein to identify the machine or person operating or controlling the crimping machine <NUM>.

By monitoring the temperature of the terminal <NUM>, either directly or indirectly, the quality of the crimp may be monitored <NUM>. By analyzing the temperature of the terminal <NUM>, either directly or indirectly, other characteristics of the crimp may be analyzed. For example, the temperature may be used to calculate the forces imported onto the terminal <NUM>, as the amount of force is related to the temperature of the terminal <NUM> after crimping has occurred.

In operation, after the movement of the crimp tooling from the closed position back toward the open position is detected, the sensors <NUM> are activated and send data to the controller <NUM>.

In an exemplary embodiment, as represented by <NUM> in <FIG>, the thermal characteristics of the crimp are measured, either directly or indirectly, during the crimp stroke by the one or more thermal sensors <NUM>. The thermal characteristics are measured at predetermined intervals based on either time or crimp tooling position. For example, a predetermined sample time may be selected, and the thermal characteristics may be measured at each of the discrete sample times. Alternatively, or additionally, the thermal characteristics may be measured when the crimp tooling is at a predetermined crimp height position. The position of the crimp tooling may be detected by a distance sensor (not shown) or the like.

The controller <NUM> may create a measured temperature profile of the crimp based on the measured thermal characteristics. The measured thermal profile is then compared to an acceptable temperature profile or an acceptable temperature profile range of known successful crimps, as represented by <NUM> in <FIG>. Alternatively, the measured thermal characteristics may be compared to known acceptable temperature characteristics or profiles of the particular materials being used. The acceptable temperature profile or an acceptable temperature profile range may be preinstalled in the controller <NUM> or may be developed by the user on-site and stored in the controller <NUM>. If the measured temperature profile is within the acceptable temperature profile range, the controller <NUM> will indicate that the crimp is proper. If the measured temperature profile is not within the acceptable temperature profile range, the controller <NUM> will indicate that the crimp is not acceptable and reject the crimp, as represented by <NUM> in <FIG>. Data relating to the thermal characteristics, the peak temperature, the amount of area below the temperature curve, the shape of the temperature curve, or any combination may be analyzed to determine if the crimp is defective.

The use of thermal data and analysis to monitor the termination of wires or conductors has other uses beyond just crimp related applications. For example, thermal analysis of welds (ultrasonic, resistive, etc.), molding, stamping, thermoplastic welding and heat staking (plastic riveting) is beneficial to determine if a proper electrical connection has been secured. In addition to collecting thermal data directly after the terminal has occurred to determine if a proper termination has been affected, the thermal sensors may be used to collect thermal data during the termination process, allowing the controller to continue the terminal process until such time that a good termination/connection is achieved.

By collecting thermal data during the crimping process, either by non-contact methods such as thermal sensors or by direct contact thermal sensors or both the data can be used to provide a quality assessment without the need for destructive testing. In fact, the thermal data can be used to create nondestructive 3D thermal cross sectioning. The use of the thermal data is beneficial in many applications, particularly in applications in which there is very little force variation between crimping a terminal with a wire or crimping one without a wire, for example, when crimping aluminum wire.

Claim 1:
A wire terminating apparatus (<NUM>) which allows for determining the quality of a termination of a wire, the apparatus comprising:
a wire termination zone (<NUM>);
a sensor (<NUM>) mounted on the wire terminating apparatus (<NUM>) proximate the wire termination zone (<NUM>);
wherein the sensor (<NUM>) monitors the properties of the termination to determine if the termination is defective,
characterised in that the sensor (<NUM>) is a thermal sensor, that monitors thermal properties of the termination by collecting thermal data at various times resulting in a time series of images and analysing time varying data so collected.