WO2004048965A1

WO2004048965A1 - Automatic ultrasonic testing apparatus to evaluate the structural integrity of lead-acid battery terminal posts

Info

Publication number: WO2004048965A1
Application number: PCT/IB2002/005439
Authority: WO
Inventors: Ricardo Flores-Lira; Jose Hector Lopez-Lozano; Jose Luis Rocha Guerra
Original assignee: Enertec Comercial S. De R.L. De C.V.
Priority date: 2002-11-26
Filing date: 2002-11-26
Publication date: 2004-06-10

Abstract

An ultrasonic testing apparatus for on or offline evaluation of the structural integrity of lead-acid battery terminal posts in battery manufacturing. The apparatus includes: means for controlling the reception, gate keeping (14), positioning (15), guiding (13) and transporting of lead-acid batteries (21) across the different operation stations of the apparatus; means for application of ultrasonic coupling medium (17) on the surface of the battery terminal posts; means for the engaging and disconnection of ultrasonic coupler devices to the battery terminal posts; means for transmitting ultrasonic waves from transducers (25) through the body of the lead-acid battery post; means for detecting and analyzing, the structural integrity of the terminal posts by a reflected echo; means for deciding the rejection or the acceptability of lead-acid batteries; and means for separating the failed batteries towards a rejects position. The main elements and functions of the apparatus can be adapted to any lead-acid battery manufacturing line.

Description

AUTOMATIC ULTRASONIC TESTING APPARATUS TO EVALUATE THE STRUCTURAL INTEGRITY OF LEAD-ACID BATTERY TERMINAL POSTS

TECHNICAL FIELD

This invention relates generally to an apparatus for detecting failed lead acid batteries, and more specifically, to an automatic ultrasonic testing apparatus for evaluating the structural integrity of battery terminal posts on and offline, in the manufacturing plants.

BACKGROUND ART

There has been much effort at developing apparatus for determining the condition of lead- acid batteries in the automotive field and, in particular for determining the acceptability of such batteries. It is desirable that such apparatus be as simple as possible to use, and involve the exercise of a minimum amount of judgment by the operator, so that personnel with a relatively low level of skill or experience may operate it. It is further important that such apparatus be as accurate as possible. It is also important that the period of time required to analyze a battery not be unreasonably long, and it is further desirable that the analysis be performed in as wide a variety of different conditions as possible.

Apparatus for automatically analyzing the condition of automotive batteries are known in the prior art. Such apparatus are disclosed in patents such as the U.S. Patent No. 4,193,025 of C. E. Frailing et al. In this apparatus for automatically testing automotive-type, lead acid storage batteries three separate tests are made. The results thereof are compared to predeteraiined standards in a specified order, to maximize the information obtained about the battery. The three tests measure ( 1 ) whether the battery meets its cold cranking rating by drawing a predetermined load current therefrom for a predetermined period of time and determining whether the battery voltage is above a specified level at the end of that period, (2) whether the battery terminal voltage is above another specified level at the end of a predetermined period of time following the completion of the first test, and (3) whether the internal resistance is acceptably low. If the battery passes the first test, it is known to be acceptable. If the battery fails the first test and passes the second test, it is known to be unacceptable. If the battery fails the first and second tests, the third test is performed. If the battery then passes the third test, it is known to be acceptable but to require a recharge, whereas if the battery then fails the third test the acceptability of the battery is then not yet determined and it must be recharged and retested. Frailing et al in the U.S. Patent No.4,322,685 also disclosed an apparatus for detecting the presence of a defective cell in a lead-acid battery. The apparatus measures the terminal potential of the battery when it is subject to a constant resistance load. If that potential is found to increase more than a predetermined amount during a time interval following the application of the load, the battery is known to have at least one defective cell.

Jacobs et al in the U.S. Patent No. 4,423,379 disclosed a system and method for testing a battery having an internal impedance by generating digital battery parameter values corresponding to the battery parameters at different points in time by means of current, voltage and temperature measurement circuits and an analog-to-digital converter. An electrical load is periodically placed on the battery and the battery is also charged between loadings in order to provide battery parameter values during different battery conditions. A microprocessor coordinates the testing of the battery and the measuring of the battery parameter values, as well as the calculation of test criteria based on those values in order to quickly and accurately analyze the condition of the battery.

Eberle in the U.S. Patent No.4,214,204 disclosed a high rate battery testing apparatus. In this apparatus, the high rate terminal blocks are adjustably mounted to service batteries. Each battery to be processed is located and clamped by a high rate test head, after which a load is connected across the battery terminals to effect the testing operation. The terminal blocks are preferably of the same configuration as the molding templates used to mold the battery terminals, thereby ensuring precise alignment and excellent contact between the battery terminals and the water cooled terminal blocks.

Pies et al in the U.S. Patent No. 4,102,205 described a method and apparatus for ultrasonic nondestructive testing of workpieces including automatic compensation of echo responsive electrical signals commensurate with preprogrammed test parameters. In this apparatus, the test parameters include at least one of the following: depth dependent correction of the individual DGS (distance, gain, size) values for each respective probe; correction for material related properties of the workpiece and coupling medium; correction for temperature affecting the testing of the workpiece. Preferably, a compensating signal generated commensurate with the sum of the correction signals is used for varying either the gain of a received amplifier or a predetermined level provided to a comparator circuit or both. Embodiments disclosed are applicable for processing both analog and digital echo responsive electrical signals.

Ostroff et al, in the U.S. Patent No. 4,451,791 disclosed a method and apparatus for electrically testing individual elements of multi-cell batteries comprises sequentially locating batteries at a test location whereat they are engaged by test probes which are sequentially associated with a testing device which tests the individual cells. If faults are detected, the individual faulty cell is marked. Auxiliary test indicator lights provide a visual indication of the individual testing of each cell as it occurs. Other battery testing methods and apparatus, have been proposed over the years as alternatives to lead-acid battery testing. Some of such apparatus are described in U.S. Pat. No. 3,873,911 to Keith S. This apparatus is electronic in nature, measuring the dynamic conductance of the battery which is said to be proportional to the maximum power available from the battery. Haruhisa Furuishi described in the U.S. Patent No. 3,753,094 an ohmmeter for measuring the internal resistance of a battery and directly reading the measured resistance value.

It should be appreciated by those skilled in the art that an improper or defective battery terminal post is substantially detrimental to the overall performance of the electric storage battery. There is also a hazard that the electric storage battery may explode causing damage to persons and/or property. In addition, the electrical connections of the positive and negative battery posts to the positive and negative battery bushings are essential to the safety of the electrical storage battery. If a battery post is not fused to the battery bushing, the electrical storage may leak acid and/or acid fumes from the battery bushing. For these reasons, it is very important to have a reliable testing method to evaluate the physical integrity of the battery posts.

To ensure that a reliable electrical contact is maintained, the battery terminal connector must be constructed such that it will remain securely attached to the terminal post of the battery even when subjected to road vibrations and various other adverse conditions. At the same time, the battery terminal connector must permit the battery cable to be easily disconnected and reconnected from the battery terminal posts, maintaining the strength retention of the terminal post, the ease with which the terminal post can be attached to and detached from the battery, and the ability to be reused numerous times without a significant loss in its structural integrity.

In view of the importance of the structural integrity of the battery terminal posts, and because specific testing methods are not known for detecting battery terminal post defects, providing a new automatic testing apparatus for evaluating the physical integrity of terminal posts in lead-acid batteries is an object of the present invention.

SUMMARY OF THE INVENTION

Some of the possible battery terminal posts non-destructive testing techniques are: high rate discharge, x-ray testing, acoustic testing, gamma rays testing and ultrasonic testing. The high rate discharge is unable to detect specifically defective posts and it does not work with unformed batteries. Such batteries are those, which have been constructed, but not yet electrically charged by the first time. The x-rays require special safety equipment and do not penetrate lead. Acoustic testing is unreliable to detect terminal post defects under noisy environments. Ga ma rays require even tougher security requirements than the x-rays technique. Ultrasonic testing is broadly utilized to detect defects of structural components because it is a very sensitive technique, could detect almost any imperfection, is easy to perform and relatively inexpensive. However, any previous application of the ultrasonic testing technique to evaluate the structural integrity of lead-acid battery components are not known.

The ultrasonic testing method, utilizes the different transmission and reflection characteristics of sonic waves at a boundary between dissimilar media. When a sound wave strikes the boundary between two different transmission media, part of the energy is reflected and part is transmitted. In ultrasonic testing, the time measurements between a transmitted pulse and the receipt of a reflected echo pulse from a non-uniformity in the object under test is a measure of distance. However, current ultrasonic methods for detection, analysis and sizing of flaws require important modifications for each different application.

This invention relates to an ultrasonic testing apparatus for evaluating on and offline battery manufacturing, the structural integrity of lead-acid battery terminal posts. The apparatus includes: means for controlling the reception, gate keeping, positioning, guiding and transporting of lead-acid batteries across the different operation stations of the apparatus; means for the application of an ultrasonic coupling medium on the surface of battery terminal posts; means for the engaging and disconnection of ultrasonic coupling devices to the battery terminal posts; means for transmitting ultrasonic waves from transducers through the body of lead-acid battery post; means for detecting and analyzing, the structural integrity of the terminal posts by a reflected echo, means for deciding the rejection or the acceptability of lead acid-batteries; and means for separating the failed batteries towards a rejects position. The main elements and functions of the apparatus can be fitted to any lead-acid battery manufacturing line.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevated sectional view of an automatic ultrasonic testing apparatus to evaluate the structural integrity of lead-acid battery terminal posts according to the present invention.

FIG. 2 is a sectional plant view of an automatic ultrasonic testing apparatus to evaluate the structural integrity of lead-acid battery terminal posts according to the present invention. DETAILED DESCRIPTION OF THE PRESENT INVENTION

The apparatus for ultrasonically testing on or offline in battery manufacturing, the integrity of lead-acid battery terminal posts, according to the present invention includes: means for controlling the reception, gate keeping, positioning, guiding and transporting of lead-acid batteries across the different operation stations of the apparatus, where transporting comprises rolls, chain, belt, or band conveyors; means for the application of an ultrasonic coupling medium on the surface of battery terminal posts; means for the engaging and disconnection of ultrasonic coupler devices to the battery terminal posts; means for transmitting ultrasonic waves from transducers through the body of lead-acid battery post; means for detecting and analyzing, the structural integrity of the terminal posts by a reflected echo; means for deciding the rejection or the acceptability of lead acid- batteries; and means for separating the failed batteries towards a rej ects position. The main elements and functions of the apparatus can be adapted to any lead-acid battery manufacturing line.

In a preferred embodiment, FIG. 1 and FIG.2 show the apparatus 10 comprising a frame 11 , which supports a conveyor 12. According to FIG.2, battery guiding means 13, battery gate keeping means 14, and battery positioning means 15, are located across the length of the conveyor 12. As shown in FIG. 1, to control the flow of batteries across the battery gate keeping station 16, the coupling medium application station 17, and the ultrasonic testing station 18; the apparatus 10 is provided with sensors and control means (not shown). The batteries 19 and 20 are at the coupling medium application station 17; the batteries 21 and 22 are at the ultrasonic testing station 18. In the coupling medium application station 17, flexible feeder heads 23 are located above the batteries 19 and 20. The flexible feeder heads 23 are supported by adjustable supporting means 24. According to each battery design, the flexible feeder heads 23 are positioned to properly dispense a coupling medium on top posts surface by pumping means (not shown) . Upon completion of coupling medium application, batteries 19 and 20, are displaced to the ultrasonic testing station 18. The ultrasonic testing heads 25 are provided with ultrasonic sensors and coupling means. The testing heads 25 are supported on member 26 moving on sliding guides 27. The testing heads 25 are moved towards and away from batteries by a piston 28 mounted on a support member (not shown). Once the batteries 21 and 22 are in the ultrasonic testing station 18, the testing heads 25 engage the batteries for testing, by lowering the rod of piston 28. Once battery terminal posts are engaged by heads 25, ultrasonic waves are transmitted from a transducer (not shown) through the body of the battery terminal posts. Software and hardware means (not shown) are used to evaluate the structural integrity of the battery terminal posts by a reflected echo from the internal body of the battery terminal post. The decision to reject or to accept the lead acid-battery is made by comparing and analyzing the transmitted and reflected echo of ultrasonic wave signals of each battery terminal post against reference signals of good and bad lead-acid battery terminal posts.

Upon completion of the ultrasonic testing of the battery terminal posts, the piston 28 raise the testing heads 25, and the batteries 21 and 22 are displaced from the testing station 18. If no battery terminal post has been detected as faulty, the batteries 21 and 22 continue to the next step in the manufacturing line. If any of the battery terminal posts have failed, the battery is marked and pushed off the conveyor onto a rejects station 29 by the action of the piston 30, which is shown in Fig. 2.

The apparatus 10 is designed to be incorporated into a battery manufacturing line such that it receives batteries to be tested from an input conveyor (not shown) and delivers tested batteries to an output conveyor (not shown) which transports the batteries to the next step in the manufacturing line, or onto a rejects station 29; depending on the results of the ultrasonic testing of battery terminal posts. Many testing results on and off line in our manufacturing facilities, have proved that: the ultrasonic testing apparatus of the present invention can be applied in massive evaluation of the structural integrity of battery terminal posts, that the testing cost per inspected unit is very low, that it is a very easy to operate and to maintain, that it is very reliable, and can be performed before and after the battery formation process.

Although a specific form of the invention has been selected for illustration by the drawings and the previous description was drawn in specific terms for the purpose of describing this form of the invention, this description is not intended to limit the scope of the invention, which is defined in the appended claims. The main elements and functions of the apparatus referred to in the present invention could be considered in the manufacturing of new ultrasonic testing apparatus, or in the modifications of any other equipment performing other functions of the manufacturing process of batteries, where the modifications could consist in adding said main elements of the present invention to the previous functions of the modified apparatus.

Claims

CLAIMSWE CLAIM:

1. An ultrasonic testing apparatus for evaluating on or off line in lead-acid battery manufacturing lines, structural integrity of battery terminal posts, comprising: means for controlling reception, gate keeping, positioning, guiding and transporting of batteries across the different operations performed in said apparatus; means for applying an ultrasonic coupling medium on a surface of the battery terminal posts; means for engaging and disconnecting ultrasonic coupling devices to the battery terminal posts; means for transmitting ultrasonic waves from transducers through a body of the battery posts; means for detecting and analyzing the structural integrity of lead-acid battery terminal posts by a reflected echo of ultrasonic waves signals from said terminal posts; means for deciding rejection or acceptability of lead acid-batteries by comparing and analyzing transmitted and reflected echo of ultrasonic waves signals from each terminal post tested against reference signals; and means for separating failed batteries towards a rejects station.

2. An ultrasonic testing apparatus according to claim 1, wherein the transport means comprise rolls, chain, belt, and band conveyors.

3. An ultrasonic testing apparatus according to claim 1 , wherein the means for engaging and disconnecting the ultrasonic coupler device to the battery terminal posts comprise supporting members, sliding guides and pistons.

4. An ultrasonic testing apparatus according to claim 1 , wherein the means for separating the failed batteries comprise a piston.

5. An ultrasonic testing apparatus according. to claim 1, further comprising means for adapting said apparatus to any other equipment used in a battery manufacturing process.