How to determine the quality of a drilled hole

Abstract

Described herein is a method for indicating quality of a drill hole for a manual drilling operation in a composite material, comprising the steps of continuously monitoring (S01a) a value of a first parameter indicative of a displacement over a time interval of a drill bit head relative to a workpiece (6) using a measurement device (2, 2') disposed on a drilling tool (1), storing (S02) the continuously monitored value of the first parameter, correlating (S03) the continuously monitored value of the first parameter with a first threshold value, and determining (S04) whether the quality of the drill hole (10) is acceptable or not based on the correlation of the continuously monitored value with the first threshold value.

Description

[Technical field]

[0001] The present invention relates to the field of drilling in industrial applications, in particular manual drilling, more particularly manual drilling in composite materials. [Background technology]

[0002] Although automation has become a large part of industrial drilling applications and assembly lines, manual drilling is still used in various applications, for example in aircraft manufacturing, but increasingly in other industries such as lightweight manufacturing and the autonomous vehicle industry. Typically, workpieces used in the aircraft industry are made of composite materials, meaning that they are composed of various layers of different materials. For example, composite materials with alternating carbon fiber layers and metal layers such as aluminum or titanium are very common. Drilling such composite materials poses challenges, especially when operators manually drill holes in composite materials. With conventional solutions, problems can arise if the operator does not push the drill forward into the hole or if the operator pushes the drill forward into the hole too hard. To understand such problems, it is best to imagine drilling a piece of wood. If the drill hole is pushed too hard, the hole will bend outwards from the exit hole and wood fibers will protrude from the exit hole. On the other hand, if the operator does not apply enough pressure on the drill, the drill bit will generate excessive heat and the equipment or workpiece may be thermally damaged or catch fire.

[0003] The bending of wood fibers outwards is usually an aesthetic problem and does not substantially affect the quality of the workpiece. However, when drilling holes in composite materials, bending outwards from the exit hole can be a major problem, requiring reworking and, in the worst case, replacement of the entire workpiece. Carbon fibers in particular are sensitive to bending outwards from the fibers, and such bending can affect the structural strength of the workpiece. Also, heat generated in the workpiece can affect the material and destroy the workpiece, at least in the vicinity of the drilled hole. Reworking an aircraft workpiece or replacing an entire aircraft workpiece can lead to substantial economic impacts, meaning that such reworking or replacement can be costly. Furthermore, reworking can result in the need to drill holes with a larger diameter than the existing holes, which can only be done a limited number of times, reducing the workpiece's operating time, and reworking can only be done, in some cases, twice, after which the workpiece must be replaced. In addition to the above, undetected holes with poor hole quality in composite materials can have serious consequences, for example, if such poor quality drilled holes weaken the structure of the aircraft. In view of the above, there is a need to provide a method that can prevent or at least check and indicate the creation of unacceptable holes when manually drilling workpieces or components. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above, it is an object of the present invention to provide a method that allows observing, monitoring and indicating the quality of drill holes in a composite material during or after manual drilling of the composite material.

[0005] Another object of the present invention is to provide a drilling tool having a measuring device capable of carrying out the method disclosed herein. [Means for solving the problem]

[0006] The inventors of the present invention have found that during manual drilling, a sensor can be used in the drilling tool or power drill, which can continuously monitor the value of a first parameter, for example at predefined intervals. The inventors have further found that by continuously monitoring the value of the first parameter, the quality of the drilled hole can be detected by correlating the continuously monitored value with at least one threshold value. The first parameter can be the displacement over time of the drilling tool or power drill relative to the workpiece. In this way, the speed of movement of the drill head to the workpiece can be determined, and thereby the quality of the drilled hole can be evaluated.

[0007] Disclosed herein is a method for determining drill hole quality of a manual drilling operation in a composite material, the method comprising: - continuously monitoring, by means of a measuring device arranged on the drilling tool, a value of a first parameter indicative of the displacement over a time interval of the drill head relative to the workpiece; - storing the continuously monitored values ​​of a first parameter; - correlating the continuously monitored values ​​of a first parameter with a first threshold value; - determining whether the quality of the hole is acceptable based on a correlation between the continuously monitored values ​​and a first threshold value; Includes.

[0008] The above method allows the quality of drill holes in composite materials to be indicated in real time and at the end of the drilling operation.

[0009] The measurement sensor may, for example, monitor the value continuously at predetermined intervals. Depending on the application, these intervals may be very short, for example in the range of one hundredth (1 / 100) of a second or even microseconds.

[0010] Alternatively, the quality of the drilled holes can be indicated after the drilling operation has finished, which can be when the drilling tool is stopped or when the operator indicates that the drilling operation is complete.

[0011] In one embodiment, the method further includes a step of indicating in a tactile, visual or acoustic manner whether the hole quality is unacceptable based on the determination of the hole quality and the correlation of the continuously monitored value of the first parameter with a first threshold value.

[0012] This allows an operator to be alerted and ensured to be notified in case of an indication of a quality problem with a drill hole. Alternatively or additionally, this indication can be sent to a network or database, where the quality problem is then recorded and stored.

[0013] In a further embodiment, the first threshold may be an upper threshold.

[0014] The upper threshold may be, for example, a maximum displacement between the drill bit head and the workpiece over time to ensure that the drill bit head does not advance too quickly into the workpiece.

[0015] Alternatively, the first threshold may be a lower threshold.

[0016] The lower threshold is used to detect if the displacement of the drilling tool relative to the workpiece over time is too slow to avoid heating.

[0017] The method may also include correlating the continuously monitored value with upper and lower thresholds to keep the actual value of the first parameter within an appropriate range for optimal drill hole quality.

[0018] In one embodiment, the first parameter indicative of the displacement over a time interval may be an acceleration or a velocity.

[0019] In another embodiment, the method may include continuously monitoring a value of a second parameter indicative of a rotational speed of the drill bit head, storing the second parameter, correlating the continuously monitored value of the second parameter with a second threshold value, indicating whether the hole quality is acceptable based on the correlation of the continuously monitored value with the second threshold value, and determining the hole quality and indicating in a tactile, visual or audio manner whether the hole quality is unacceptable based on the correlation of the continuously monitored value with the second threshold value.

[0020] A first parameter indicating the rotational speed of the drill bit head as well as the displacement of the drilling tool relative to the workpiece may lead to greater quality control since the displacement and rotational speed are correlated and the first parameter is dependent on the second parameter or vice versa.

[0021] The second parameter can be correlated to the first parameter for optimal quality control and drill hole quality. For example, a higher rotation speed can lead to a larger displacement per time, unless a threshold value is exceeded.

[0022] In one embodiment, the second threshold may be an upper threshold, a lower threshold, or both.

[0023] In yet another embodiment, the measurement device may be an accelerometer.

[0024] The accelerometer can be used to detect how fast the drilling tool is accelerating during drilling.

[0025] In another embodiment, the measurement device may be a laser capable of generating at least one laser beam directed toward the workpiece when the drilling tool is in use.

[0026] The measuring device can also be embodied as an optical sensor instead of a laser.

[0027] The laser can also function as an accelerometer since it can measure displacement over time continuously at predetermined intervals.

[0028] In yet another embodiment, the method may include detecting a third parameter representative of a position of the drill bit head on the workpiece, correlating the third parameter with the first parameter or the second parameter, and providing a tactile, visual or acoustic indication of whether the correlation returns a value that exceeds a third threshold.

[0029] Again, the instructions can be sent to a database or network. An advantage of this third parameter is that the method can use different thresholds depending on the exact position of the drill bit head in the composite material, such that the tolerance and therefore either the first or second threshold and / or the upper and / or lower threshold can be adapted to the material that the drill bit head is currently drilling.

[0030] However, it is believed that this third parameter needs to be correlated with the first and second parameters for optimal performance adaptation and to provide maximum value. The rotational speed of the drill bit, for example, can be adapted to the material at hand and changed when the drill bit head enters another material in the composite.

[0031] Disclosed herein is a drilling tool including a measurement device, a memory and a processing circuit, the drilling tool being configured to carry out a method according to any of the above.

[0032] Although the present invention has been described according to several embodiments, the present invention is not limited to the combinations disclosed above, but rather covers the above disclosed concepts with all modifications that can be conceived by a person skilled in the art within the scope of his or her knowledge of the technology.

[0033] The invention will now be described in more detail, by way of example only, by means of embodiment(s) and with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0034] [Figure 1] 1 shows a schematic diagram of a manual power drill with a measuring device for drilling holes in a composite material. [Diagram 2] Schematically shows a view and embodiment similar to that of FIG. 1, but with an alternative measuring device connected to a manual power drill. [Diagram 3] 1 illustrates a schematic diagram of a method according to an embodiment disclosed herein. [Figure 4] 4 illustrates generally another method according to another embodiment disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] FIG. 1 shows a manual power drill 1 including a measuring device 2. A drill bit 4 is engaged with the manual power drill 1, which is used to drill a hole in a workpiece 6 made of a composite material. The drill bit 4 comprises a drill bit head. The manual drill 1 is shown without an operator for illustrative purposes. Saw particles 8 are removed from the composite material 6 during the drilling operation. A hole is formed in the composite material by rotation of the drill bit 4 and manual depression of the manual power drill 1 by the operator. The measuring device 2 is designed to detect a first parameter indicating the displacement over time of the manual drill 1. The measuring device 2 can thus comprise a gyroscope type sensor 3 or an accelerometer type sensor 3. The measuring device 2 detects or measures whether the displacement or acceleration over time is within a certain range, for example a first lower threshold and a second upper threshold. As long as the value of the first parameter is within the predefined range, the quality of the drilled hole 10 is evaluated as approved. This quality approval is visually indicated to the operator or recorded in a database. The same applies if the value of the first parameter is outside of the approved range, which is visually notified to the operator and / or stored in the database. Alternatively, the indication can be tactile or audible.

[0036] The monitoring of the first parameter can be done in real time and the operator can be notified in real time. As an example, a manual power drill can include two visual indicators, such as LED arrows, that can indicate whether the operator needs to press harder if the actual value of the first parameter is near or below a first lower threshold, or whether the operator needs to release pressure if the actual value of the first parameter is near or above a first upper threshold.

[0037] This procedure is or can be the same for different embodiments disclosed herein. An indication of whether the actual value of any measured or monitored parameter is within, exceeds, or falls below a threshold value can be monitored in real time. Also, the current value of any measured parameter can be indicated or displayed or illustrated in real time. This is possible for any embodiment disclosed herein.

[0038] FIG. 2 shows a similar embodiment to FIG. 1, but the power drill 1 is equipped with another measuring device 2′. The measuring device 2′ shown in FIG. 2 can for example comprise an optical sensor 5, which is able to detect the distance between itself and thus the power drill 1 and the workpiece 6. Also, such detection as shown in FIG. 2 can be performed in real time, so that the acceleration can be detected, since the distance between the measuring device 2′ and the workpiece 6. In addition, such distance detection also allows the computer or central control device (not shown) of the power drill to calculate exactly where the drill bit head is currently located in the workpiece 6. This information can be used for other control procedures, such as for example the rotational speed of the drill bit.

[0039] The optical sensor 5 of the measuring device as shown in FIG. 2 can be an optical sensor, thus a camera, or alternatively a laser sensor capable of emitting at least one laser beam.

[0040] Another parameter that may be monitored using any of the measuring devices or sensors described and illustrated, or directly via the power drill 1, is the rotational speed of the drill bit head during the drilling operation.

[0041] 1 to 2, the measuring device 2, 2' is arranged outside the power drill 1. However, it is also conceivable that the measuring device 2, 2' is integrated in the power drill 1 or in a housing thereof.

[0042] Referring to FIG. 3, there is shown and described a general process or method for determining parameters indicative of displacement, position, angle and acceleration.

[0043] 3 shows a method according to the invention for manually drilling holes in composite materials, comprising the following method steps: The method is used to determine the drill hole quality of a manual drilling operation in a composite material, - a step S01a of continuously monitoring, by means of a measuring device arranged on the drilling tool, the value of a first parameter indicating the displacement over a time interval of the drill head relative to the workpiece; - a step S02 of storing the continuously monitored values ​​of a first parameter; a step S03 of correlating the continuously monitored values ​​of a first parameter with a first threshold value; - a step S04 of determining whether the quality of the hole is acceptable based on a correlation between the continuously monitored values ​​and a first threshold value; Includes.

[0044] The method may further comprise a step S05 of indicating in a tactile, visual or acoustic manner whether the quality of the hole is unacceptable based on the determination of the quality of the hole and on the correlation of the continuously monitored value of the first parameter with the first threshold value. However, this indicating step is optional and is not necessary to implement the invention. The quality control of the drill holes may be performed in other areas, for example in a central database in the factory.

[0045] The first threshold is an upper threshold. The upper threshold may be an upper limit value in distance / time, for example, cm / s, mm / s, mm / ns. A measured or monitored value approaching the upper threshold may indicate that an operator of a manual power drill is applying too much pressure to the power drill.

[0046] The first threshold may alternatively be a lower threshold, which is a lower limit value of a distance / time interval and associated velocity or acceleration, for example in cm / s, mm / s or mm / ns. A measured or monitored value approaching the lower threshold may indicate that an operator of the manual power drill is applying too little pressure to the power drill.

[0047] In one embodiment, the first threshold may be an upper threshold and a lower threshold.

[0048] The first parameter related to the distance / time interval may be the speed / velocity or acceleration.

[0049] In another embodiment of the invention shown in FIG. 4, the method may include the steps S01b of continuously monitoring a value of a second parameter indicative of a rotational speed of the drill bit head, S02 of storing the second parameter, S03 of correlating the continuously monitored value of the second parameter with a second threshold value, S04 of determining whether the hole quality is acceptable based on the correlation of the continuously monitored value with the second threshold value, and S05 of indicating in a tactile, visual or acoustic manner whether the hole quality is unacceptable based on the determination of the hole quality and the correlation of the continuously monitored value with the second threshold value.

[0050] Similarly in FIG. 4, the indication step is an optional step and is not required to take advantage of the present invention and to use the methods disclosed herein to improve the quality of a drill hole or to determine whether there is a quality problem.

[0051] The second threshold may be an upper threshold, a lower threshold, or both.

[0052] Further referring to FIG. 4, the measuring device 2′ of the power drill 1 may further comprise an optical sensor or a laser in addition to the acceleration sensor, and the method may further comprise the steps of detecting S01c a third parameter indicative of the position of the drill bit head in the workpiece, storing S02 the continuously monitored values ​​of the third parameter, correlating S03 the third parameter with the first parameter or the second parameter, determining S04 whether the hole quality is acceptable based on the correlation of the continuously monitored values ​​with a third threshold, and providing a tactile, visual or acoustic indication S05 of whether the correlation has returned a value above the third threshold.

[0053] The above steps can be used, for example, to provide different acceleration tolerances based on the exact location of the drill bit head within the composite. As an example, aluminum may have a higher tolerance for the acceleration or linear velocity of the drill bit than, for example, a carbon layer. The same is true for the correlation between the rotational speed (rpm) of the drill bit head and the exact location of the drill bit head.

[0054] The position parameter can be used to correlate to the first or second parameter, and thus the acceleration and / or rotational speed of the drill bit head, as explained above. Alternatively or additionally, a third parameter of position can be used to indicate to the operator when the drill bit head begins to penetrate to the outside of the composite material or workpiece 6, so that the operator knows that he can slowly release the pressure of the power drill to avoid a punch through phenomenon of the drill hole 10.

[0055] The fourth parameter may be a pair of angle values, a first angle value for a left-to-right direction and a second angle value for a top-to-bottom direction.

[0056] Further disclosed herein is a power drill 1 having circuitry and electronic memory to enable the power drill 1 to carry out any of the process or method steps described above, according to any of the methods shown in Figures 4 to 5, or any suitable combination thereof.

[0057] The measurement device disclosed herein is for mounting on a power drill, but may include any combination of the sensors described. The measurement device need not be configured exactly as disclosed in any of Figures 1-3. For example, it may include an accelerometer and a laser, or a gyroscope and an optical sensor, or only one of these. [Explanation of symbols]

[0058] 1 Drilling tools 2' Measuring device 4 Drill bits 5 Optical Sensors 6 Workpiece 10 Drill holes

Claims

1. 1. A method for determining drill hole quality for a manual drilling operation in a composite material, comprising: - a step (S01a) of continuously monitoring the value of a first parameter indicative of the displacement over a time interval of the drill bit head into the workpiece (6) using a measuring device (2, 2') arranged on the drilling tool (1), the parameter being adapted to detect the displacement over time of said drilling tool; - storing (S02) said continuously monitored value of said first parameter; - a step (S03) of correlating said continuously monitored value of said first parameter with a first threshold value; - determining (S04) whether the quality of the drilled hole (10) is acceptable based on a correlation between the continuously monitored value of the first parameter and the first threshold value; A method comprising:

2. 2. The method of claim 1, further comprising the step (S05) of indicating in a tactile, visual or acoustic manner whether the quality of the drilled hole (10) is acceptable based on the determination of the drilled hole quality and correlation of the continuously monitored value of the first parameter with the first threshold value.

3. The method of claim 1 , wherein the first threshold is an upper threshold.

4. The method of claim 1 , wherein the first threshold is a lower threshold.

5. The method of claim 1 , wherein the first parameter indicative of a displacement over a time interval is an acceleration.

6. 5. The method of claim 1, further comprising the steps of: continuously monitoring (S01b) a value of a second parameter indicative of a rotational speed of the drill bit head; storing (S02) the second parameter; correlating (S03) the continuously monitored value of the second parameter with a second threshold value; determining (S04) whether a quality of the drilled hole (10) is acceptable based on the correlation of the continuously monitored value of the second parameter with the second threshold value; and indicating in a tactile, visual or acoustic way whether the quality of the drilled hole (10) is unacceptable based on the determination of the quality of the drilled hole and the correlation of the continuously monitored value of the second parameter with the second threshold value.

7. The method of claim 6 , wherein the second threshold is an upper threshold, a lower threshold, or both.

8. The method of claim 5, wherein the measuring device (2) comprises an accelerometer (3).

9. 5. The method according to claim 1, wherein, when the drilling tool is in use, the measuring device comprises a laser sensor capable of generating at least one laser beam directed towards a workpiece.

10. 7. The method of claim 6, further comprising the steps of: detecting and continuously monitoring (S01c) a value of a third parameter indicative of a position of the drill bit head on the workpiece (6); correlating (S03) the third parameter with the first parameter or the second parameter; determining (S04) whether the quality of the drilled hole (10) is acceptable based on the correlation of the continuously monitored value of the third parameter with a third threshold value; and providing a tactile, visual or acoustic indication (S05) of whether the quality of the drilled hole (10) is unacceptable or acceptable.

11. A drilling tool (1) comprising a measuring device, a memory and a processing circuit, said processing circuit being adapted to carry out the steps of the method according to any one of claims 1 to 4.

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