TIGHTENING TOOL EQUIPPED WITH A TIGHTENING QUALITY CONTROL DEVICE

Abstract

Tightening tool comprising a body (11), containing control circuits and an electronic processing unit having at one end a handle (12) for gripping by an operator performing the tightening, and at the other end an arm (13). Such arm at its free end comprises a seat (16) into which a plurality of inserts can alternatively be inserted, suitable for engaging the tool with a corresponding type and/or size of a mechanical member on which the tool is intended to act to perform a tightening operation. Sensor means are provided on said arm suitable for detecting tightening conditions exerted on said mechanical member. Such sensor means comprise at least one inertial measurement unit (IMU) connected to such electronic processing unit, capable of detecting tool rotations about the three cartesian axes (x, y and z) and direct accelerations along such axes.

Claims

1. Tightening tool comprising a body (11), containing control circuits and an electronic processing unit having at one end a handle (12) for gripping an operator who performs the tightening, and at the other end an arm (13), said arm at its free end comprising a seat (16) in which a plurality of inserts suitable for engaging the tool with a corresponding type and/or size of a mechanical member on which the tool is intended to act to act perform a tightening operation, on this arm there are sensor means suitable for detecting the tightening conditions exerted on this mechanical member, characterized in that said sensor means including at least one inertial measurement unit (IMU) connected to such an electronic processing unit, capable of detecting tool rotations around the three cartesian axes (x, y and z) and direct accelerations along said axes.

2. Tool according to claim 1, wherein said unit (IMU) detects the acceleration that is impressed along the bolt tightening axis (Y) to check if there have been any interruptions in the tightening operation.

3. Tool according to claim 1, wherein said unit (IMU) measures the acceleration along the tightening axis to detect a possible misalignment between the theoretical tightening axis and the real one, thus understanding whether the tightening of the bolt does not was performed along the correct axis.

4. Tool according to claim 1, wherein said unit (IMU) measures the acceleration and therefore the rotation of the wrench with respect to the point of application of the tightening torque and having stored a pre-defined tightening sequence in the processing unit, by comparison with these predefined sequences, it is possible to verify the correct tightening sequence.

5. Tool according to claim 1, wherein said unit (IMU) measures any sudden decelerations that can be stored and evaluated, to define if after the wrench it can still be used, or if it requires maintenance or repairs.

Description

[0012] Further objects and advantages of the present invention will become clear from the following description and from the attached drawings, provided purely by way of non-limiting example, in which:

[0013] FIG. 1 is a perspective view of the tightening tool according to the present invention;

[0014] FIGS. 2 and 3 are front and rear views of the tool of FIG. 1;

[0015] FIG. 4 shows a side view of a torque wrench aligned with the bolt to be tightened, showing the axes of the possible rotations of the wrench;

[0016] FIG. 5 shows a front view of a torque wrench aligned with the bolt to be tightened, showing the axes of the possible rotations of the wrench.

[0017] With reference to the aforementioned figures, the tightening tool according to the present invention is a torque wrench and comprises a body 11 containing electronic control circuits having on one side of said body a handle 12 (preferably containing rechargeable batteries for powering the tool) and on the other side an arm 13. Advantageously, a display 14 for viewing information and operating data is provided on the body 11 and a keyboard 15 allows data and commands to be entered.

[0018] Naturally, it is understood that if the processing or storage of data requires a unit which cannot be easily or completely contained in the body 11, the body 11 can be connected, by means of a cable or a wireless connection, to external processing units. A wired connection can also be envisaged to provide external power supply. A plurality of inserts can be alternatively pluggable in a suitable seat 16 at the end of the arm 13. For example, each insert will be suitable for engaging the wrench with a corresponding type and/or dimension of mechanical member or element (screw, nut, etc.) on which the tool is destined to operate.

[0019] Although for simplicity's sake inserts all having a similar dimension are shown, elongated inserts or inserts with arms of a particular shape can also be provided, as known in the art.

[0020] Each insert may comprise internally a transponder in a suitable position (typically in the plugging shank to the seat 16) to be coupled to a suitable antenna close to the seat 16 when it is mounted on the tool.

[0021] The manners for coupling between transponder and antenna for the activation of the transponder (usually known as “tag”) and the communication are widely known and will therefore not be described in detail here.

[0022] The tool comprises sensors of the torque exerted on the mechanical member, made with groups of strain gauges preferably arranged in the arm.

[0023] According to an aspect of the present invention, the tightening tool comprises an inertial measurement unit (IMU) capable of detecting rotations about the three Cartesian axes x, y and z and direct accelerations along these axes.

[0024] Such unit is connected to the central processing unit of the tool, and can take the following measurements during tightening.

[0025] For example, during the tightening of a B-bolt, by analysing the acceleration on the Y-axis (bolt tightening axis), it is possible to understand whether the tightening operation has been interrupted or whether the bolt has been tightened completely. In addition, by measuring parameters such as torque and tightening angle (via the IMU), it is possible to determine whether tightening has been carried out in several stages or in a single action to completion.

[0026] By measuring the acceleration along the tightening axis it is possible to detect a possible misalignment between the theoretical and actual tightening axes, thus understanding whether the bolt has not been tightened along the correct axis, possibly damaging the thread of the hole.

[0027] When a conventional wrench is used to tighten a series of bolts, it is almost impossible to control the inclination of all the bolts during tightening. In fact, during use, operators may handle the wrench incorrectly with respect to the inclination of the bolt to be tightened. When the wrench is used to tighten the same type of bolt each time, the inclination is known but the operator cannot precisely control it without using another tool.

[0028] Using the inertial gauge, on the other hand, by measuring the acceleration and therefore the rotation of the wrench with respect to the torque application point and having stored a predefined tightening sequence in the processing unit, it is possible to understand whether the tightening operations on all bolts have been carried out correctly.

[0029] Another problem that can be avoided is if the operator starts to tighten a bolt, gets distracted and then starts to tighten the wrong one again, which is at a different inclination. Through the measurement of the IMU and by detecting the predefined tightening sequence stored in the processing unit, the system can issue a fault signal.

[0030] Joint inclinations can also be recorded in the tightening sequence. This makes the measurement made in the previous point even more useful, in which not only the direction between one bolt and the next is measured but also their inclination.

[0031] Acceleration measurement can also provide indications on whether the tool has been subjected to shocks or falls involving sudden deceleration. These measurements can be stored and evaluated to determine whether the wrench can still be used afterwards, or whether it requires maintenance or repair.

[0032] In addition, acceleration readings can allow the tool's electronic processing unit to rotate the digital display, compatible with the axis of gravity, to make it easier for the operator to read the data on the display during use.