The disclosure pertains to the field of testing vehicle motor rotary accessory devices. More particularly, the disclosure relates to a device for the more accurate testing of the alternator of a motor vehicle engine or the like.
It is well known in the vehicle industry to employ analytical tools in connection with the analysis of vehicle motors and their individual components and systems. One such engine component that is often analyzed is the alternator. Alternators are used in connection with an engine and are typically belt driven by the engine. Alternators have internal components, which when rotated supply electrical power to a vehicle and/or an engine. Alternators are typically removable but oftentimes rigidly mounted via a bracket to the engine block or the chassis of the vehicle.
It is often desirable to test alternators after removal from a vehicle at a parts supply sales location, at a repair facility or the like. For example, such testing may be desirable for an existing alternator motor before installing a new alternator. In the event that the existing alternator may pass the test, a user may eliminate that the alternator as the cause of a problem with the vehicle.
Alternator test equipment typically utilizes an AC motor as prime mover for rotating the alternator under test and the alternator is coupled to the prime mover through a belt for power transmission. During the test procedure, the prime mover rotates the alternator under test and applies known loads on the alternator, measures the output and checks the ability of the alternator to generate power at a particular current and voltage.
One of the assumptions during the test regarding the test equipment is that there is no loss or a minimum power transmission loss, which will not affect the test results of the alternator. This assumption is not valid and it may lead to failing a good alternator due to transmission belt slippage. In this regard, the drive belt may slip and accordingly not rotate the alternator as desired. This may result in an indication that the alternator is not properly functioning.
Thus, a need exists for determining whether the test equipment is properly operating before and/or during testing of the alternator so that the alternator function may be properly determined.
The foregoing needs are met, to a great extent, by the present disclosure, wherein in one aspect, an alternator tester that determines whether the alternator under test is being properly driven to ensure more accurate test results.
In an exemplary aspect, a diagnostic tool for testing the performance of a component of a vehicle is provided and can include a processor that can process test information from an alternator component of the vehicle and can control and activate the alternator component during an alternator test; a memory that can store the test information of the alternator component and software that can operate the alternator component of the vehicle, a motor having a pulley that can connect to the alternator, a first load component that can be controlled by the processor to put a first load on the alternator during testing, and an analog to digital converter (ADC) that can provide an output voltage of the alternator, wherein the processor determines a ripple frequency from the output voltage.
In another embodiment, a method of testing an alternator can include the steps of starting an alternator drive motor with a processor of an alternator tester, receiving a voltage output from an analog to digital converter with the processor, determining a first ripple frequency from the voltage output with the processor, determining a second ripple frequency after a first load is applied by a first load component that is controlled by the processor, calculating a first difference between the first and second ripple frequencies by the processor, and determining if the first difference exceeds a predetermined percentage by the processor.
In still another embodiment, a diagnostic tool for testing the performance of a component of a vehicle is provided and can include a processor that can process test information from an alternator component of the vehicle and can control and activate the alternator component during an alternator test, a memory that can store the test information of the alternator component and software that operates the alternator component of the vehicle, a motor that can drive the alternator during the test, a power supply that can supply power to the motor during testing, a first load component that can be controlled by the processor, wherein the first load can apply a first load on the alternator during testing, and an analog to digital converter (ADC) that can provide an output voltage of the alternator, wherein the processor determines a ripple frequency from the output voltage.
There has thus been outlined, rather broadly, certain aspects of the disclosure in order that the detailed description herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional aspects of the present disclosure that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one aspect of the present disclosure in detail, it is to be understood that the present disclosure is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The present disclosure is capable of aspects in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present disclosure. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present disclosure.
The present disclosure will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An aspect in accordance with the present disclosure provides an alternator tester for testing an alternator that includes a device for more accurate testing of the alternator of a motor vehicle engine or the like.
An aspect of the present testing apparatus is illustrated in
The tester 100 also includes an alternator belt tensioning arrangement generally designated 116, an alternator mounting arrangement generally designated 118. The tester 100 may also include the ability to test a starter and may include a starter motor holder arrangement generally designated as 120. The belt tensioning arrangement 116 and the alternator mounting arrangement 118 may be mounted directly to the base plate 114.
The alternator belt tensioning arrangement 116 and the mounting arrangement 118 together hold the alternator in place for testing. An installation assembly that includes one or more mounting pins (not shown) can be placed in the mounting arrangement 118 in order to mount the alternator. The alternator can be horizontally or vertically mounted depending on the type of alternator. The pins are replaceable to allow flexibility for current and future applications.
Also shown in
The starter motor holder arrangement 120 includes a quick release ratchet system, wherein the starter is placed on a pad and held in place by the ratchet system. The starter motor holder arrangement 120 includes, a support pad 130, a handle 132 and a release lock 134 that when operated engages and disengages a lock (pawl, for example) from a ratchet (both not shown). The starter motor holder arrangement 120 helps to eliminate the use of straps, and alternatively uses the quick ratchet to hold the starter without the need of any additional holding mechanism or end user assistance during the test. Thus, the aforementioned arrangement makes the loading and unloading of components to be tested much more efficient. The starter motor may be placed on the support pad 130 for testing. Upon the placement, the operator squeezes the release lock and presses down on the handle 132 to engage the starter motor and then releases the lock so that the lock is again reengaged. The starter motor may be powered by a transformer (not shown) in order to simulate operating environments. The transformer may be powered by an external power source and may provide test power to the starter motor via a heavy duty cable and clamps. Power leads 128, including, for example, battery lead, ground lead, solenoid lead and sense lead are connected to the starter motor in order to conduct the tests.
The tester 100 may output “Good/Bad” or “Pass/Fail” results to the end user. An end user printout that details test results and provides technical advice for other potential problems can be provided to the end user.
Turning now to
The tester 200 also includes an alternator belt tensioning arrangement generally designated 216, an alternator mounting arrangement generally designated, and a starter motor holder arrangement generally designated as 220. Each of the belt tensioning arrangement 216, the alternator mounting arrangement, and the starter motor holder arrangement 220 are mounted directly to the base plate (not shown).
The test adapters 226 and power leads 228 may be connected to the alternator or starter motor in order to provide test information to tester 200. Additionally, a drive belt (not shown), such as a serpentine or V belt or the like, can be connected to the alternator, the motor of the alternator and drive motor to simulate the operating environment in the vehicle. A gas piston may be used for belt tension to ensure consistent belt tension during testing and thereby eliminating over tensioning or slipping belts that may affect test results.
The starter motor holder arrangement 220 includes a quick release ratchet system, wherein the starter is placed on a pad and held in place by the ratchet system. The starter motor holder arrangement 220 includes, a support pad, a handle 232 and a release lock 234 that when operated engages and disengages a lock (pawl, for example) from a ratchet (both not shown). The starter motor holder arrangement 220 helps to eliminate the use of straps, and alternatively uses the quick ratchet to hold the starter without the need of any additional holding mechanism or end user assistance during the test. Thus, the aforementioned arrangement makes the loading and unloading of components to be tested much more efficient. The starter motor may be placed on the support pad for testing. Upon the arrangement, the operator squeezes the release lock and presses down on the handle 232 to engage the starter motor and then releases the lock so that the lock is again reengaged. Power leads 228, including, for example, battery lead, ground lead, solenoid lead and sense lead are connected to the starter motor in order to conduct the tests.
In the aspect depicted in
In the closed position, the protective door cover 222 eliminates the possibility of hands getting caught in moving parts or projectiles potentially contacting the end user. The protective door cover 222 may employ a door interlock switch (not shown) to disable tests while the protective door cover 222 is open. Alternatively, the protective door cover 222 may include a viewing window so that the operator can observe the testing components during the tests.
The processor 304 is configured to communicate with an internal memory 308 and an external memory 310. The internal memory 308 and/or the external memory 310 can be any memory including, for example, compact flash, SD (secure digital), USB flash drives, and the like. A universal serial bus (USB) port 312 communicates with the processor 304 and provides a connection for various USB compatible devices, such as, for example, an external memory 310, a printer 314, a radio frequency identification (RFID) reader 332 and/or a diagnostic tool 336. The RFID reader 332 functions to read identifying information about the tested component containing an RFID chip once it is within a detection range. The RFID chip may contain information about the alternator or starter motor such as alternator/starter motor type, serial number, manufacturer, date of production or shipment, previous test results, electrical specifications, maintenance information, serial number, lot number, warranty information, a manufacture data code, method of shipment and the like.
The processor 304 also communicates with an interface module 324. The interface module 324 communicates with other external devices or external websites, such as a technical service bulletins (TSB) 334 through Internet 322. The interface module 324 includes a database (or access the internal memory 308 or the external memory 310 that stores the database) for storing information associated with the tested components and information associated with the diagnostic test performed by the tester 100. The RS-232 ports 316 also communicate with other external devices, such as a computing device 320, a bar code reader 318 and/or the diagnostic tool 336. In another exemplary aspect, the interface module 324 communicates with the technical service bulletins (TSB) 334 via the point-of-sale (POS) terminal 326. Further details of these components are described in U.S. patent application Ser. No. 13/463,292 filed May 3, 2012 and incorporated by reference herein in its entirety.
As described above, Alternator testers typically use a 120 VAC Motor to provide rotational drive to the alternator by means of a belt. Other configurations are contemplated as well. The drive capability of the motor to the alternator is largely dependent on the tension of the belt to prevent slippage under load. Without adequate belt tension, the belt can slip at either the driving pulley, on the motor, or at the driven pulley on the alternator, or both.
The alternator is designed to generate the proper DC voltage (typically 13.8 to 14.5 VDC) when driven over a range of RPM (revolutions per minute), typically about 800 to 10,000 RPM. If the alternator RPM slows to less than the low design RPM, the alternator's ability to generate the design voltage may not maintained. When the belt between the motor pulley and the alternator pulley is not fully tightened by the operator adequately, the belt can slip on one or both of the pulleys and the alternator RPM may drop below the design RPM, which will result in the Alternator output voltage being below the design voltage i.e., 13.8 v. Having this occur during the testing of the Alternator output would result in a failure decision of the Alternator Test. This “False” failure can cause the Alternator to be returned for warranty, thus incorrectly causing the cost of replacing the alternator. Additionally, it may cause the technician to incorrectly determine the cause of the problem in the power system. Therefore a “False” failure due to belt slip is highly undesirable.
The alternator is typically designed with inductive coils that create an alternating current (AC) voltage, which is rectified using diodes with each coil to produce a direct current (DC) voltage for charging the battery in a vehicle. The rectification by the diodes is not complete in that there is some level of ripple in the voltage after the rectification. The ripple frequency is generally directly proportional to the RPM of the alternator, the number of coils and/or diodes used in the specific design of the alternator.
This disclosure uses this ripple frequency proportional to the alternator RPM to determine if belt slip may be occurring. Belt slip when testing an alternator with the belt is not tightened sufficiently typically occurs when an electrical load is connected to the alternator output. This electrical load requires the alternator to produce more current in order to maintain the design output voltage. Producing more current requires more input power to the alternator pulley through the belt. The increase in power demand can cause belt slip.
When determining whether belt slip is occurring, the absolute (specific amount of RPM such as 655 rpm) RPM is not needed, because the RPM before the load is connected compared to the RPM after the load is connected can be analyzed for change. Specifically, if the RPM after the load is connected is significantly lower than the RPM before the load is connected, the reduced RPM is likely due to belt slip.
This disclosure measures the frequency of the voltage ripple on the output of the alternator, and converts it to a voltage related to the alternator RPM. Recording the frequency while the alternator is running (being driven by the motor through the belt) but without any electrical load as F(nl) (Frequency with no-load) and recording the frequency shortly after the electrical load is connected to the alternator as F(l1) (Frequency with load-one). The determination of whether the belt is slipping or not is determined by calculating the difference of the two frequencies; (Fnl−Fl1)=F(dif). Determining whether the frequency difference is larger than the expected amount that the motor may slow down due to the electrical load only, this can be described as X % of F(nl). If the frequency F(dif) is greater than frequency with no-load F(nl), times the percent of expected frequency slow down, it is highly likely there is belt slip occurring. With this condition the test can be stopped and the operator instructed to tighten the belt before starting the test again. This would prevent the cost of an alternator replacement under warranty on a “False” failure.
In other aspects, the belt slip check may be determined after a second heavier electrical load is connected. In this regard, it may be desirable to load the alternator with two separate loads. Having two separate loads allows a lighter load to be applied if the AC line voltage is low, and may be too low for the alternator tester to operate or trip a circuit breaker if the heavier load were applied. The belt slip procedure may be applied to analyze the RPM before and after the second load is connected, in the event that the belt slips only when the heavier load is applied.
The motor 330 may be driven by a 120 V alternating current power source 402. Other power sources are contemplated as well. The power source may be directly connected to the AC motor 330 or through a motor control 404. The motor control 404 may connect and disconnect the power from the power source 402 to the motor 330. More particularly, the motor control 404 may be a solenoid switch that is controlled by the processor 304. Other types of switches are contemplated as well.
After power from the power source 402 is provided to the AC motor 330 through a closed switch of the motor control 404, the motor 330 rotates and subsequently rotates the alternator 410. Rotating the alternator 410 will provide a power output from the B+ output of the alternator 410.
During this rotation of the alternator 410, the processor 304 or similar components may measure the ripple frequency of the power generated by the alternator 410 at described below in more detail. The alternator tester may further include an alternator load that may include a switch 414 that may be controlled by the processor 304 and a resistive load 416 that is grounded. This alternator load may cause the belt 412 to slip as described herein.
The alternator tester may further include a second load that includes a switch 418 that may be controlled by the processor 304 and a resistive load 420 that is grounded. This second alternator load may further cause the belt 412 to slip as described herein.
In 514, the difference between the two frequencies is determined, and is further determined whether or not it exceeds a particular percentage (X %) at 514. If it is determined in step 514 that the difference exceeds a particular percentage (yes), then the alternator test will be stopped at 516 and the technician instructed to tighten the belt and retest at 518.
On the other hand, if the difference does not exceed a particular percentage (no), the alternator test will continue at 520 and be completed at 522.
Additionally, the belt slip process 500 may further include a second load process 524. In this regard, after 520, the second load may be turned on at 526, the ripple frequency recorded at 528, and another difference calculation conducted at 530. In 532 the difference between the ripple frequency determined at 510 and the ripple frequency determined at 528 may be compared to determine whether or not the difference exceeds a particular percentage (X %). If the difference exceeds the percentage (yes), then the alternator test may be stopped at 534. Additionally, the technician may be instructed to tighten the belt and retest. On the other hand, if the difference does not exceed the predetermined percentage (no), the alternator test may be completed at 522.
In further aspects, the frequency may be checked after motor is started to ensure alternator is running at a predetermined minimum RPM. In yet another aspect of the disclosure, the disclosure could be used to check for belt slip when the alternator is first started. Shortly after the motor is started to drive the alternator at a desired RPM, the alternator RPM may be checked to ensure that it has reached a minimum RPM. The minimum RPM would be predetermined and specified for each alternator. In this regard, a RPM specific to each alternator is required because for a motor with a specific design RPM and a motor pulley with a specific diameter, the alternator RPM may still be different due to the diameter size pulley it is designed with. In addition the frequency of the ripple is dependent on the number of coils and diodes in the specific alternator design, and is not the same for all alternators. So the alternator pulley diameter and the number of coils and diodes would need to be known for a minimum RPM. These parameters can be recorded with the part number for a specific alternator, and used to set variables in the Belt Slip algorithm to calculate the minimum RPM.
Further details of the alternator test process are described in U.S. patent application Ser. No. 13/463,292 filed May 3, 2012 and incorporated by reference herein in its entirety.
Accordingly, the disclosure as described herein determines whether the test equipment is properly operating before and/or during testing of the alternator so that the alternator function may be properly determined.
The disclosure may be implemented in any type of computing devices, such as, e.g., a desktop computer, personal computer, a laptop/mobile computer, a personal data assistant (PDA), a mobile phone, a tablet computer, cloud computing device, and the like, with wired/wireless communications capabilities via the communication channels.
Further in accordance with various embodiments of the disclosure, the methods described herein are intended for operation with dedicated hardware implementations including, but not limited to, PCs, PDAs, semiconductors, application specific integrated circuits (ASIC), programmable logic arrays, cloud computing devices, and other hardware devices constructed to implement the methods described herein.
It should also be noted that the software implementations of the disclosure as described herein are optionally stored on a tangible storage medium, such as: a magnetic medium such as a disk or tape; a magneto-optical or optical medium such as a disk; or a solid state medium such as a memory card or other package that houses one or more read-only (non-volatile) memories, random access memories, or other re-writable (volatile) memories. A digital file attachment to email or other self-contained information archive or set of archives is considered a distribution medium equivalent to a tangible storage medium. Accordingly, the disclosure is considered to include a tangible storage medium or distribution medium, as listed herein and including art-recognized equivalents and successor media, in which the software implementations herein are stored.
The many features and advantages of the present disclosure are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the present disclosure, which fall within the true spirit, and scope of the present disclosure. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the present disclosure to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the present disclosure.
This application claims priority to U.S. patent application entitled, ALTERNATOR TESTER HAVING BELT SLIP DETECTION, filed Mar. 15, 2013, having a Ser. No. 61/791,438, the disclosure of which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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61791438 | Mar 2013 | US |