DESC:FIELD
The present disclosure relates to the field of torque measuring systems.
BACKGROUND
In today’s high speed processing of vehicle assembly, precision equipment and trained people using them play a critical role in defining high quality standards and timely delivery of work. The use of battery operated tools has become very common in view of the growing demands for quality products. Battery operated tools such as torque wrenches or battery guns are easy to operate, handy, and free from entangling air hoses / electrical cables. These tools are used to assemble a number of parts on a vehicle using tightening clamp members such as nuts and bolts, in a very short time.
A typical battery operated tool kit of the kind discussed above, for example, includes an electric motor and a battery that powers the electric motor. Further, charger is provided in the kit to charge the battery. Furthermore, LED (light emitting diode) indicators are provided on the battery tool to indicate various kinds of information relating to the functioning of the tool like torque OK/ torque NOT OK indications, and the battery charge status.
While using these battery operated tools, a common practice for confirming whether the torque delivered by a given battery operated tool is as per the standard or as desired is by observing the indications of the LED indicators provided on the battery operated tool. An operator operating the battery operated tool gets to know whether the torque is as per the requirement based on the indications received and in case any modification is required in terms of the torque applied, the operator may manually adjust the battery operated tool using a control mechanism.
It is observed that conventional battery operated tools do not provide any solution to prevent/eliminate human errors involved during the operation. Due to the comparatively small size of the LEDs and its short glowing time, it is often difficult to observe the indications in all operating conditions. Human error caused due to the deficiencies of conventional battery operated tools leads to defects, rework, poor quality, and late delivery.
There is, therefore, felt a need to provide a torque measuring system and a method that alleviates the aforementioned problems.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a torque measuring system that facilitates precise delivery of a preset level of torque from a torque tool.
Another object of the present disclosure is to provide a torque measuring system which indicates desirability/non-desirability of the applied torque.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present invention envisages a torque measuring system and a method thereof for monitoring fastening operations that are performed by a torque tool device in an assembly line. The system comprises a torque measuring unit, a tuned transmitter-receiver pair, and a control unit. The torque measurement unit is mounted on the torque tool device and is configured to measure torque generated by the torque tool device. The torque measurement unit is further configured to generate electrical signals corresponding to the measured torque. The tune transmitter-receiver pair includes a transmitter and a receiver. The transmitter is electronically coupled to the torque measurement unit and is configured to receive the electrical signals. The transmitter unit is further configured to transform the received electrical signals into radio frequency signals and transmit the radio frequency signals in free space. The receiver is wirelessly coupled to the transmitter and is configured to receive the radio frequency signals. The receiver is further configured to transform the radio frequency signals into the electronic signals corresponding to the measured torque value.
The control unit includes a repository and a processor. The repository is configured to store a lookup table of acceptable torque values and appropriate actions corresponding to the torque values. The processor co-operates with the receiver of the tuned transmitter-receiver pair and the repository, and is configured to compare the electronic signals corresponding to the measured torque value with the acceptable torque values stored within the repository. The processor is further configured to generate at least three control signals based on the comparison for monitoring and managing the fastening operations.
In an embodiment, the torque tool device includes a screw tightening unit that is configured to generate torque for performing tightening operations.
In one embodiment, the system further includes a first position sensor and a second position sensor. In an embodiment, the first position sensor (105) and the second position sensor (120) are a Gyro sensor. The first position sensor is placed at an operative first end of the assembly line. The first position sensor is configured to detect entry of an automobile body placed on the assembly line, and is further configured to generate a first sensed signal based on the detection of entry of the automobile. The second position sensor is placed on an operative second end of the assembly line, and is configured to detect exit of the automobile body placed on the assembly line. The second position sensor is further configured to generate a second sensed signal based on the detection of exit of the automobile body.
In an embodiment, the system further includes a first indicator and a second indicator. The first indicator is configured to indicate a positive status based on the control signal received from the processor. The second indicator is configured to indicate a negative status based on the control signal received from the processor. In one embodiment, the first indicator and the second indicator provides audio and/or visual indications. In another embodiment, each of the first indicator and the second indicator is selected from a light emitting diode (LED), a buzzer, or any combination thereof.
Further, in an embodiment, the processor is configured to control the movement of the assembly line based on the measured torque and by means of the control signal generated by the processor.
In yet another embodiment, the torque tool device includes a battery pack that is configured to power the torque tool device. In still another embodiment, the system further includes a power supply unit that is configured to provide power to the receiver and the processor.
The method of measuring torque for monitoring fastening operations performed by the torque tool device in an assembly line comprises following steps:
• generating torque for performing fastening operations by means of a screw tightening unit;
• measuring the generated torque value and generating electrical signals corresponding to the measured torque value, by means of a torque measurement unit;
• transforming the generated electrical signals into radio frequency signals and transmitting the radio frequency signals, by means of a transmitter;
• receiving the radio frequency signal and transforming the radio frequency signals into electronic signals, by means of a receiver;
• comparing the electronic signals corresponding to the measured torque value with acceptable torque values stored within a repository, by means of a processor; and
• generating at least three control signals based on the comparison, by the processor.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
The present disclosure will now be explained in relation to the non-limiting accompanying drawing, in which:
Figure 1 illustrates a block diagram of a torque measuring system;
Figure 2 illustrates a block diagram of a torque tool device of the torque measuring system of Figure 1;
Figure 3 illustrates a block diagram of a control unit and a receiver of the torque measuring system of Figure 1; and
Figure 4 illustrates a flowchart for a method of measuring torque for monitoring fastening operations performed at an assembly line; and
Figure 5 illustrates a flowchart for a method of monitoring fastening operations in an assembly line set-up using the torque measuring system of Figure 1.
LIST OF REFERENCE NUMERALS
100 – Torque measuring system
101 – Torque tool device
101’ – Transmitter
102 – Control unit
104 – Tuned transmitter-receiver pair
110 – Receiver
105 – First position sensor
115 – Processor
120 – Second position sensor
125 – Assembly line
130 – First indicator
135 – Second indicator
205 – Torque measurement unit
210 – Screw tightening unit
220 – Transmitting antenna
225 – Battery pack
305 – Receiving antenna
310 – Repository
315 – Power supply unit
DETAILED DESCRIPTION
While using the conventional battery operated torque tools, a common practice for confirming whether the torque delivered by the given battery operated torque tool is as per the standard or as desired is by observing the indications of LED indicators provided on the battery operated tool. An operator operating the battery operated torque tool gets to know whether the torque delivered is as per the requirement based on the indications received, and in case any modification is required in terms of the torque applied, the operator may manually adjust the torque tool using a control mechanism.
It is observed that conventional battery operated torque tools do not provide any solution to prevent/eliminate human errors involved during the operation. Due to the comparatively small size of the LEDs and its short glowing time, it is often difficult to observe the indications in all operating conditions. Human error caused due to the deficiencies of conventional battery operated tools leads to defects, rework, poor quality, and late delivery.
A preferred embodiment of a torque measuring system, of the present disclosure will now be described in detail with reference to the Figure 1 through Figure 5.
Figure 1 illustrates a block diagram of a torque measuring system 100. Figure 2 illustrates a block diagram of a torque tool device 101 of the torque measuring system 100. Figure 3 illustrates a block diagram of a control unit 102 and a receiver 110 of the torque measuring system 100.
The present invention envisages the torque measuring system 100 (hereinafter referred as “the system”) for monitoring fastening operations performed by a torque tool device 101 in the assembly line 125. The system 100 comprises a torque measuring unit 205, a tuned transmitter-receiver pair 104, and a control unit 102. In an embodiment, the torque tool device 101 is a torque wrench, a battery operated torque tightening gun, and the like. The torque tool device 101 is used for performing the fastening operation of clamp members such as nuts and bolts.
In accordance with the present disclosure, the torque measurement unit 205 is mounted on the torque tool device 101 and is configured to measure the torque generated by the torque tool device 101. In an embodiment, the screw tightening unit 210 is configured to generate torque for performing fastening operations. In an embodiment, the screw tightening unit 210 includes a motor wherein the motor is configured to generate torque. The torque measurement unit 205 is electronically coupled to the screw tightening unit 210 of the torque tool device 101, and is configured to measure torque value generated by the torque tool device 101. The torque measurement unit 205 is also configured to generate electrical signals corresponding to the measured torque.
A pseudo-code depicting the functionality of the torque measurement unit 205 to measure the torque, in accordance with an embodiment of the present disclosure, is as follows:
• Input Distance_Vector = r;
• Input Force Vector = F;
• Input Torque = T;
• T = r*F;
• Display Result;
• End.
The tune transmitter- receiver pair 104 includes a transmitter 101’ and a receiver 110. The transmitter 101’ is electronically coupled to the torque measurement unit 205 and is configured to receive the electrical signals generated by the torque measurement unit 205. The transmitter 101’ is further configured to transform the received electrical signals into radio frequency signals and transmit the radio frequency signals in free space. In an embodiment, the transmitter 101’is configured to transmit the radio frequency signals by means of a transmitting antenna 220. In an exemplary embodiment, the transmitting antenna 220 is a multi-directional antenna.
In an embodiment, the assembly line 125 referred to herein is that of a radiator tightening assembly, wherein a plurality of radiators is tightened onto a number of automobile bodies.
The receiver control unit 102 is wirelessly coupled to the torque tool device 101 by means of the tune transmitter-receiver pair 104. The receiver 110 is configured to receive the radio frequency signals transmiited by the transmitter 101’ by means of a receiving antenna 305. In an embodiment, the receiving antenna 305 is a multi-directional antenna. The receiver 110 is further configured to transform the received radio frequency signals into the electronic signals corresponding to the measured torque.
The control unit 102 includes the repository 310 and a processor 115. The repository 310 is configured to store a lookup table of acceptable torque values and appropriate actions corresponding to the torque values. The processor 115 co-operates with the receiver 110 and the repository 310. The processor 115 is configured to compare the electronic signals corresponding to the measured torque value with the acceptable torque values stored within the repository 310. The processor 115 is further configured to generate at least three control signals based on the comparison for monitoring and managing the fastening operations.
In an embodiment, the processor 115 processes the signals received by the receiving antenna 305 to provide an output in terms of torque adequacy. For example, if the signal values are within a preset range, a torque OK indication is provided or else torque NOT OK indication is provided, by means of a first indicator 130 and a second indicator 135 respectively. In one embodiment, the processor 115 and other output modules are powered by a 24V DC power supply unit 315. In one embodiment, the power supply unit 315 takes power from a 230V AC supply.
• A pseudo-code depicting the functionality of the control unit 102, in accordance with an embodiment of the present disclosure, is as follows:Store acceptable torque values and appropriate actions
record pairs { N, Indication}
var pair array slot [x. y]
{
function Row(x1)
Case 1: i = hash(x1) mod Slots;
{
if slot[i] is not occupied, then
return I;
}
Case2: i = (i + 1) mod Slots
function lookup(x1);
i := findSlot(x5);
if slot[i] is occupied, then
return slot[i] value;
else
return not found.
}
• If (Angle < 0.5 degrees), then
Torque = {0, 0, 0}
else
if (Angle > 180 degrees), then
Torque = {0, 0, 1}
• Torque = Normalize(Torque) * Force, and
• if (Time2 < Time1), then Torque = -TorqueDetermine whether the torque is adequate or not.
If torque = X,
then indicate “TORQUE OK”
ENDIF
torque = X1,
then indicate “TORQUE NOT OK”.
In one embodiment, the system 100 further includes a first position sensor 105 and a second position sensor 120. The first position sensor is placed at an operative first end of the assembly line 125. The first position sensor 105 is configured to detect entry of an automobile body placed on the assembly line, and is further configured to generate a first sensed signal based on the detection of entry of the automobile. The second position sensor 120 is placed at an operative second end of the assembly line, and is configured to detect exit of the automobile body placed on the assembly line. The second position sensor 120 is further configured to generate a second sensed signal based on the detection of exit of the automobile body. In an embodiment, each of the first position sensor (105) and the second position sensor (120) is a Gyro sensor.
In an exemplary embodiment, the first position sensor 105 is deployed at an entry point of the assembly line 125 for sensing the presence of the automobile body. Upon sensing the presence of an automobile body, a signal is sent to processor 115 of the receiver unit 102. Simultaneously, an operator carries out the fastening work, as required, using the torque tool device 101 onto the automobile body, for example, the operator starts fastening the radiator onto the automobile body using clamping means such as nuts and bolts. During the fastening process, the transmitter 101' of the torque tool device 101 transmits signals, such as wireless signals to the receiver 110. The processor 115, processes the electrical signals to determine whether the torque generated by the torque tool device 101 during a recent fastening operation was adequate, not adequate or if the conveyor, of the assembly line 125, needs to be stopped owing to some malfunction.
The first indicator 130 is configured to indicate a positive status based on the control signal received from the processor 115. The second indicator 135 is configured to indicate a negative status based on the control signal received from the processor 115. In another embodiment, each of the first indicator and the second indicator is selected from a light emitting diode (LED), a buzzer, or any combination thereof.
In an embodiment, the first indicator 130 indicates detection of adequate torque, i.e., ‘torque OK’ while the second indicator 135 indicates, along with a buzzer, detection of inadequate torque, i.e, ‘torque NOT OK’ status.
Further, the second position sensor 120 is deployed at an exit point of the assembly line 125, senses exit of the automobile body from the mounting stage. The processor 115 is configured to control movement of the automobile body in the assembly line 125 based on the signal received from the second position sensor 120. If the exit is found positive, the automobile body is allowed to move to the next stage of assembling and the system is reset to the initial stage.
In one embodiment, the torque tool device 101 includes a battery pack 225 that is configured to power the torque tool device 101. In another embodiment, the system 100 further includes a power supply unit 315 that is configured to power the receiver 110 and the processor 115.
In still another embodiment, the screw tightening unit 210 of the torque tool device 101, and the transmitter 101’ both are operated by DC power (18 to 32 volts). In yet another embodiment, the screw tightening assembly 210 and the transmitter 101’ are operated by AC power.
Figure 4 illustrates a flowchart 400 for a method of measuring torque for monitoring fastening operations performed at an assembly line.
The method of measuring torque for monitoring fastening operations performed by the torque tool device 101 at an assembly line comprises following steps:
At step 402, generating torque for performing fastening operations by means of the screw tightening unit 210.
At step 404, measuring the generated torque value and generating electrical signals corresponding to the measured torque value, by means of the torque measurement unit 205.
At step 406, transforming the generated electrical signals into radio frequency signals and transmitting the radio frequency signals, by means of the transmitter 101’;
At step 408, receiving the radio frequency signal and transforming the radio frequency signals into electronic signals, by means of the receiver 110;
At step 410, comparing the electronic signals corresponding to the measured torque value with acceptable torque values stored within the repository 315, by means of the processor 115; and
At step 412, generating at least three control signals based on the comparison for monitoring and measuring the fastening operations, by the processor 115.
Figure 5 illustrates an exemplary method 500 of monitoring fastening operations in the assembly line 125 set-up using the system 100 of the Figure 1, in accordance with an embodiment of the present disclosure.
At Step 505, the operation starts and a vehicle or an automobile body for fastening operation is awaited on the conveyor of the assembly line 125.
At Step 510, the entry of the vehicle is read by the first position sensor 105. In addition, a torque count of the torque tool device 101 during fastening operation is counted.
At Step 515, for example, a sensor reading of ‘1’ and a torque signal count of ‘2’ are measured. Both the readings are sent wirelessly to a tightening information processor.
At Step 520, it is determined by the processor 115, in addition to taking into consideration the readings as measured in Step 515, whether the vehicle has crossed the mounting stage as read by the second position sensor 120 provided at an exit stage. For example, if a reading of the second sensor is ‘0’, i.e., the body has not moved beyond the second sensor, a torque OK indication is provided at Step 525, for example, through a ‘green’ LED and the process moves to Step 535.
If the readings at Step 520 are not in conformance with the preset values, a ‘red’ signal indicating torque NOT OK is provided at Step 530 and the conveyor of the assembly line 125 is stopped. In other words, the fastening operation failed due to inadequate torque. The process then goes back to Step 515.
At Step 535, the readings are checked once again.
At Step 540, for example, if the reading of the first position sensor 105 at the entry stage is ‘0’, the torque signal count is ‘2,’ and reading of the second position sensor 120 at the exit stage is ‘1’ (i.e., a vehicle body has passed the second sensor successfully), the vehicle body is allowed to move onto the next stage and the system is reset to the initial stage.
Else, at Step 545, the system waits for the movement of the vehicle body and repetitively checks for the desired readings as received from the first position sensor 105 and the second position sensor 120 as well as the torque signal count.
The tuned transmitter-receiver pair 104 of the torque measuring system 100 allows the torque tool device 101 and control unit 102 to communicate with each other wirelessly, thereby enabling the operator to know immediately whether the torque value generated by the torque tool device 101 is adequate or not during a fastening operation. In an embodiment, the torque tool device 101 generates a momentary signal, which is used to determine whether the torque value is as per the requirement. The response time is quick (0.001 mili seconds) as it happens wirelessly. The processor 115 of the system 100 can be implemented as an add-on module with an existing torque tool device. In an exemplary embodiment, the tuned transmitter-receiver pair 104 can be designed to work in an operating radius of 100m at a frequency of about 2.4GHz (as recommended for small application industrial use by the Wireless Planning & Coordination Wing, Department of Telecommunications, Government of India).

TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including but not limited to the realization of an attachment for a torque measurement system and a method that:
- limits the requirement of skilled labor;
- eliminates human errors involved during assembly line operations; and
- reduces the time required for performing fastening operations.
The disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully revealed the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:A torque measuring system (100) for monitoring fastening operations performed by a torque tool device (101) in an assembly line (125), said system (100) comprising:
a torque measurement unit (205) mounted on said torque tool device (101), configured to measure torque generated by said torque tool device (101), and further configured to generate electrical signals corresponding to said measured torque;
a tuned transmitter-receiver pair (104) having:
a transmitter (101’) electronically coupled to said torque measurement unit (205) and configured to receive and transform said electrical signals into radio frequency signals, said transmitter (101’) further configured to transmit said radio frequency signals; and
a receiver (110) wirelessly coupled to said transmitter (101’) and configured to receive said radio frequency signals, said receiver (110) further configured to transform said radio frequency signals into said electronic signals; and
a control unit (102) having:
a repository (310) configured to store a lookup table of acceptable torque values and appropriate actions corresponding to said torque values; and
a processor (115) co-operating with said receiver (110) and said repository (310), and configured to compare said electronic signals corresponding to said measured torque value with said acceptable torque values stored within said repository and generate at least three control signals based on said comparison for monitoring and managing said fastening operations.
2. The system (100) as claimed in claim 1, wherein said torque tool device (101) includes a screw tightening unit (210) configured to generate torque for performing tightening operations.
3. The system (100) as claimed in claim 1, wherein said system (100) further includes:
a first position sensor (105) placed at an operative first end of said assembly line, and configured to detect entry of an automobile body placed on said assembly line (125), and further configured to generate a first sensed signal; and
a second position sensor (120) placed at an operative second end of said assembly line, and configured to detect exit of said automobile body placed on said assembly line, and further configured to generate a second sensed signal.
4. The system (100) as claimed in claim 1, wherein said system (100) further includes:
a first indicator (130) configured to indicate a positive status based on said control signal received from said processor (115); and
a second indicator (135) configured to indicate a negative status based on said control signal received from said processor (115).
6. The system (100) as claimed in claim 1, wherein said processor (115) is configured to control the movement of said assembly line (125) based on said measured torque.
7. The system as claimed in claim 1, wherein said torque tool device (101) includes a battery pack (225), said battery pack (225) configured to power said torque tool device (101).
8. The system as claimed in claim 1, wherein said control unit (102) further includes a power supply unit (315), said power supply unit (315) configured to provide power to said receiver (110), and said processor (115).
9. The system as claimed in claim 4, wherein each of said first indicator (130) and said second indicator (135) is selected from a light emitting diode (LED), a buzzer, or any combination thereof.
10. The method of measuring torque for monitoring fastening operations performed by a torque tool device (101) in an assembly line (125) comprises following steps:
• generating torque for performing fastening operations by means of a screw tightening unit (210);
• measuring torque and generating electrical signals corresponding to said measured torque, by means of a torque measurement unit (205);
• transforming said generated electrical signals into radio frequency signals and transmitting said radio frequency signals, by means of a transmitter (101’);
• receiving said radio frequency signal and transforming said radio frequency signals into said electronic signals, by means of a receiver (110);
• comparing said electronic signals corresponding to said measured torque with said acceptable torque values stored within a repository (310), by means of a processor (115); and

• generating at least three control signals based on said comparison for monitoring and measuring the fastening operations, by said processor (115).