DE102017119623A1 - Torque control system and torque control method for electric shock with adjustable torque - Google Patents

Abstract

In a torque control system and method for an adjustable torque electric impact tool, a curve is first determined that determines the relationship between the high and low voltages of the tool during normal operation and the high and low torque values, respectively, of the tool at the high and low torque values Low voltages are output accordingly. Then, a target torque value that falls between the highest and lowest torque values on the relational curve is input to obtain a working voltage corresponding to the target torque value to perform a tightening operation. During the tightening process, a microprocessor of a torque control device immediately and continuously receives and uses measurement signals sent from a torque measuring device and changes in voltage, current, and motor temperature continuously detected by a voltage / current measuring element and a temperature sensing element Voltage control module to stably control the working voltage within a preset allowable variation range for the tightening torque control.

Description

The present invention relates to a torque control system for an adjustable torque electric impact tool, and more particularly to a torque control system in which AC / DC power is supplied to a brush motor or a brushless motor through a torque control device, an adjustable torque electric impact driver and an output end driven therefrom connected torque measuring device, thereby to control an output by the electric adjustable torque wrench torque for tightening a bolt on a workpiece. The present invention also relates to a torque control method for an adjustable torque electric impact tool.

There are various torque control devices and methods for adjustable torque electric shock tools. For AC / DC motors, torque, position and speed or acceleration are generally the most common parameters that need to be controlled. To control these parameters, adjustments must be made by a controller using signals fed back to it by a sensor. An electric motor is a mechanism that uses mechatronics to convert input electrical energy into mechanical energy, and outputs the latter. Therefore, controlling electrical energy is important to the electric motor. However, when controlling electrical energy, only three factors can actually be set, namely voltage, current direction and frequency. Of these three factors, the current direction controls the forward / reverse rotation of the motor, and it is a relatively simple factor; the frequency mainly refers to the control of an induction motor. However, the voltage is the real factor, which is closely related to the real objects to be controlled such as torque, position, speed and / or acceleration of the engine. That is, the voltage is the main parameter to be set by a torque control controller.

In 1 are shown conventional AC / DC motorized impact wrench with or without built-in torque measuring devices. In 1-1 is a battery powered impact wrench 2d shown a control board 21d , a DC motor 22d and a striking mechanism 23d , which is mounted in its housing and electrically with a charging battery 1 is connected has 1-2 shows a battery powered impact wrench 2d ' with a built-in torque measuring device. That means that the battery powered impact wrench 2d ' by providing a torque measuring device 24d in the housing of the battery powered impact wrench 2d out 1-1 between a striking mechanism 23d ' and an exit end 25 of which is formed. The battery powered impact wrench 2d ' has a control board 21d that have a DC motor 22d and a striking mechanism 23d ' drives to torque over an output end 25 ' thereof to apply to a socket and a bolt corresponding to the socket wrench insert in type and size to tighten a workpiece. 1-3 shows a mains operated impact wrench 2a that has a control board 21a , an AC motor 22a and a striking mechanism 23a , which is mounted in its housing and electrically connected to an AC power source 1' is connected has. 1-4 shows a mains operated impact wrench 2a ' with a built-in torque measuring device. That means that the mains operated impact wrench 2a ' by providing a torque measuring device 24a in the housing of the mains powered impact wrench 2a out 1-3 between a striking mechanism 23a ' and an exit end 25 ' thereof is formed to drive a socket and a bolt corresponding to the socket wrench insert in type and size to tighten a workpiece. The battery powered impact wrench 2d and the mains operated impact wrench 2a use the voltage to control the torque and the current control to toggle between forward and reverse rotation under open loop control. However, these controls are almost useless in terms of controlling the torque amount at the output end of the striking mechanism. On the other hand, the built-in torque measuring device transmits 24d . 24a , with the battery powered impact wrench 2d ' and the mains operated impact wrench 2a ' , Torque or angle signals to the control board 21d ' . 21a ' via wires or wirelessly during the closed-loop control tightening process, allowing for a degree of substantial improvement in torque control at the output end of the striking mechanism.

When using any of the conventional electric impact tools with adjustable torque 1 The impact mechanism mounted on the output end of the motor strikes against the output shaft of the tool to drive the socket and thereby tighten the bolt against the workpiece. Normally, the tightening torque is controlled only by adjusting the engine output or the spring tension that presses against the clutch. In some cases, a torque measuring device is mounted on a front end of the output shaft of the tool to accommodate changes in the To detect torque and the tightening angle. However, even if the same output voltage can be adjusted and the post-tightening deformation of the bolt and the rotation angle during the output shaft rotation can be monitored or even other parameters such as the tightening duration can be adjusted to control the torque, there are still others Factors that can lead to failure of the stable tightening torque control. These factors include, for example, the inevitable gradual loss of the tool's ability to output power during use, the ease of wearing away the impact mechanism of the torque impact tool or, in the case of an oil pulse torque tool, the release of the initial set torque caused by the rising temperature of oil in the engine hydraulic cylinder due to the continuous operation of the tool during a period of time, the use of the same torque settings for tightening workpieces of different Schraubfallhärte and even the changing posture of a fatigued operator during the treatment of the instrument, after working a long time. When the above-mentioned situations occur, the conventional adjustable-torque electric impact tools or the oil-pulse torque tools can only issue a warning to inform the operator of the detected result, without the possibility of solving the above-mentioned problems and any effective torque control to implement.

It is therefore an object of the present invention to provide a torque control system and torque control method for an adjustable torque electric impact tool such that measurement signals are continuously transmitted throughout the operating process to a torque control device incorporated into or externally connected to an adjustable torque electric shock tool and a microprocessor can use the changes in current or voltage detected immediately and continuously by a voltage / current measuring element to stably control the working voltage or current within a preset allowable variation range via a voltage control module, for the purpose of torque control to reach when tightening.

In order to achieve the above and other objects, the torque control method for an adjustable torque electric shock tool provided in accordance with the present invention is applicable to a tightening operation using an adjustable torque electric power tool or an oil pulse torque tool, and includes the steps of: connecting a power supply module having a torque control device externally connected to an adjustable torque electric shock tool or externally connected to an output end thereof for outputting a stable working voltage for driving the adjustable torque electric shock tool and externally connected to a torque motor tool or externally connected to an output end thereof Torque measuring device, driving the adjustable-torque electric impact tool and the torque measuring device using the highest working voltage and the lowest working voltage of the adjustable torque electric shock tool under normal conditions to perform a tightening torque calibration operation prior to the tightening operation, determining a match relationship curve of voltage and torque using the highest and lowest working voltages and the corresponding highest and lowest torque values received from the calibration operation, input of a target torque value falling between the highest torque value and the lowest torque value based on the voltage and torque coincidence curve to obtain a corresponding operating voltage, using the obtained respective operating voltage to drive the adjustable torque electric shock tool and the built-in one or externally connected torque measuring device to perform the tightening operation, and causing a microprocessor of the torque ste In order to amplify and calculate measurement signals transmitted instantaneously and continuously from the torque measuring device to the torque control device and to compare the amplified and calculated measurement signals with a voltage and torque match curve stored in advance in a memory unit of the torque control device, a corresponding working voltage is applied for performing the tightening operation under closed-loop torque control, based on changes in voltage, current and temperature immediately and continuously detected by a voltage / current measuring element and a temperature measuring element of the torque control device, stably controlling the working voltage within a preset allowable range of variation to control the tightening torque, via a voltage control module from the microprocessor, and finally off the power module and output a warning when the range of the target torque value has been reached.

Further, according to the aforementioned torque control method for an adjustable-torque electric impact tool, the tightening torque calibration operation comprises the steps of: using the torque-adjustable electric shock tool to drive the torque measuring device during the tightening torque calibration operation using the torque control device to detect the voltage / current measuring element detecting voltage signals and the torque signals detected by the torque measuring device, storing the detected voltage signals and torque signals in the storage unit of the torque control device and executing multiple sets of torque calibration operations at a plurality of points between the highest and lowest voltages, and obtaining average sample data therefrom to determine the coincidence relationship curve of voltage and Torque corresponding to the voltages and the indicates the torque values of the electric impact tool with adjustable torque during normal operation.

The aforementioned torque control method for an adjustable torque electric impact tool further includes the steps of using the adjustable torque electric impact tool to directly tighten a workpiece, and then using a torque calibration tool to obtain a torque value used to tighten or loosen the workpiece, inputting the Torque value in the torque control device via a keyboard, storing the input torque value and the changes of the voltage and the current that were detected by the voltage / current measuring element of the torque control device during the entire tightening operation, in the storage unit of the torque control device, and executing multiple sets of torque calibration operations at several Points between the highest and the lowest voltage and obtaining average sample data thereof for determining the coincidence reference Voltage and torque curve showing the voltages and corresponding torque values of the electric impact tool with adjustable torque during normal operation.

The aforesaid torque control method for an adjustable torque electric impact tool further comprises the steps of: automatically repeating the tightening torque calibration operation multiple times between the highest and lowest voltages according to a preset program for obtaining a plurality of highest / lowest working voltage groups and their corresponding highest / lowest torque values, combining and averaging multiple sets of highest torque values, lowest torque values, highest working voltages, and determining the voltage and torque match relationship curve using the obtained average highest torque value, average lowest torque value, average highest working voltage, and average lowest, respectively working voltage.

The aforementioned torque control method for an adjustable torque electric shock tool further includes the steps of: depressing a torque modification key when there is a relatively large difference between the actual torque value and the target torque value, automatically adjusting the microprocessor's match voltage and torque relationship curve on the basis of the modified torque value and displaying an adjusted controllable torque range, reentering the target torque value to obtain a adjusted working voltage corresponding to the target torque value according to the adjusted relationship curve of torque and working voltage, and using the adjusted working voltage to drive the Adjustable torque electric impact tool such that the tool performs the tightening operation with the output torque reaching the target torque value can.

The aforementioned torque control method for an adjustable torque electric shock tool further includes the steps of: inputting a calibrated torque value to replace the indicated torque value, using the substitute torque value to replace the torque value initially shown in the voltage and torque match curve; the working voltage corresponding to the initially shown torque value remains unchanged, reentering the target torque value and, based on the adjusted torque and working voltage relationship curve, driving the adjustable torque electric shock tool with the working voltage, so that the tool will tighten with the required tightening operation Can execute target torque value.

The aforementioned torque control method for an adjustable torque electric impact tool further includes the steps of: if a calibrated torque value with does not agree with the target torque value but shows stable reproducibility of the torque control, modifying only the torque value of the relationship curve while leaving the curve unchanged, monitoring and controlling changes in voltage throughout the tightening process or the torque calibration and issuing a warning about one Warning device or interrupting power supply to the adjustable torque electric shock tool when a change in voltage exceeds the allowable variation range.

To achieve the foregoing and other objects, the torque control system for an adjustable torque electric shock tool provided in accordance with the present invention includes a power supply module and a torque control device electrically coupled to the power supply module for driving an adjustable torque electric shock tool and a torque converter. A power tool installed or externally connected to an output end thereof torque measuring device for performing a tightening operation. The torque control device includes a microprocessor, a voltage control module, a voltage / current measuring element, a temperature measuring element, an input and output unit, a display unit, a warning unit, a wire / wireless communication module and a memory unit. The microprocessor amplifies and calculates torque and angle measurement signals. which are instantaneously and continuously outputted from the torque measuring device to the torque control device compares the amplified and calculated measurement signals with a voltage-torque relationship curve stored in the storage unit to obtain a target torque value-corresponding working voltage for performing the tightening operation under closed-loop torque control Stably controls via the voltage control module, the working voltage within a preset allowable range of torque control variation for tightening by the use of voltage, Str om and temperature changes, which are detected immediately and continuously by the voltage / current measuring element and the temperature measuring unit during the tightening process, and turns off the power supply module and issues a warning when the range of the target torque value has been reached. The voltage control module stably controls the working voltage within a preset torque control variation allowable tightening range based on voltage, current, and temperature changes that are detected immediately and continuously by the voltage / current measuring element and the temperature measuring unit during the tightening process. The voltage / current measuring element detects the working voltage and working current changes of the adjustable torque electric impact tool during the tightening process and returns the detected changes back to the microprocessor in time for use as a reference in voltage or current control. The temperature sensing element detects the increase in engine temperature and returns the detected temperature rise back to the microprocessor in time for use as a reference in voltage or current control. The input / output units are used to transmit various torque settings in the torque control system, measured deformation values, target torque values, and torque control signals. The display unit displays voltage and torque measuring units, target torque values and corresponding working voltages, the number of tightening operations performed and the tightening conditions. The alert unit issues warnings by light indicators or tones to remind the user of each result of the calculation and determination made by the microprocessor. The wire / wireless communication module enables data communication between the torque control device and the torque measuring device in a wired or wireless manner. The storage unit stores the highest torque value and the lowest torque value respectively corresponding to the highest working voltage and the lowest working voltage, that for the electric impact tool torque tightening operation performed with adjustable torque, and also stores other associated operating conditions. The torque measuring device is incorporated in the adjustable torque electric shock tool or externally connected to an output end thereof, and includes a torque measuring unit and a circuit board module electrically connected to a battery unit. The circuit board module further includes a microprocessor, an amplification circuit unit, an angle measurement unit, a memory unit, an input / output unit, a charging circuit unit, and a communication unit.

According to another embodiment of the above torque control system for an adjustable torque electric impact tool, the tension control module is replaced by a flow control module. In this case, the torque control device drives the adjustable torque electric shock tool and the torque measuring device using the highest working current and the lowest working current of the adjustable torque electric shock tool in normal operation to perform a tightening torque calibration operation before starting the tightening operation. The current control module also determines a compliance relationship curve of current and torque using the highest and lowest operating currents and the corresponding highest and lowest torque values obtained from the calibration process. Based on the current and torque match curve, a target torque value falling between the highest torque value and the lowest torque value may be input to obtain a corresponding operating current. The torque control device uses the obtained corresponding operating current to drive the adjustable torque electric impact tool and the built-in or externally connected torque measuring device to perform the tightening operation. In the tightening process, the microprocessor of the torque control device amplifies and calculates measurement signals sent from the torque measuring device to the torque control device immediately and continuously, and compares the amplified and calculated measurement signals with the relationship curve previously stored in the storage unit of the torque control device to obtain a corresponding working current for performing the tightening operation To obtain closed-loop torque control. Based on the voltage, current and temperature changes detected instantaneously and continuously by the voltage / current measuring element and the temperature measuring element of the torque control device, the microprocessor stably controls the operating current within a preset allowable torque control tightening range via the current control module. Finally, the power supply to the adjustable torque electric shock tool is interrupted and a warning is issued when the range of the target torque value has been reached.

In the aforementioned torque control system for an adjustable torque electric shock tool, the microprocessor modifies and adjusts the torque and torque match curve based on an input modified torque value, and when the target torque value is reentered, a new corresponding bias current is displayed based on the adjusted current and torque matching curve, and the new corresponding operating current is used to drive the adjustable torque electric impact tool to perform the tightening operation.

In summary, in the torque control system and method for an adjustable torque electric shock tool according to the present invention, the torque measuring device incorporated in or external to the output end transmits measurement signals to the on-board or externally connected torque control device throughout the tightening process and the microprocessor the torque control device uses the current or voltage detected immediately and continuously by a voltage / current measuring element to stably control the working voltage or current within a preset allowable variation range via the voltage control module or the current control module to achieve the purpose of tightening torque control to reach.

• 1 herkömmliche Elektro-Schlagwerkzeuge mit einstellbarem Drehmoment mit bzw. ohne eingebaute Drehmomentmessvorrichtung,
• 2 verschiedene andere Elektro-Schlagwerkzeuge mit einstellbarem Drehmoment mit eingebauter oder extern verbundener Drehmomentmessvorrichtung gemäß der vorliegenden Erfindung,
• die 3A - 3E Spannung-Ausgangsdrehmoment-Graphiken anhand experimenteller Beobachtungen gemäß einer ersten Ausführungsform eines Drehmomentsteuerverfahrens für ein Elektro-Schlagwerkzeug mit einstellbarem Drehmoment gemäß der vorliegenden Erfindung,
• 4 eine Beziehungskurve hoher bzw. niedriger Arbeitsspannungen und entsprechender gemessener hoher bzw. niedriger Drehmomente, die unter Verwendung der ersten Ausführungsform des Drehmomentsteuerverfahrens für ein Elektro-Schlagwerkzeug mit einstellbarem Drehmoment gemäß der vorliegenden Erfindung erhalten werden,
• 5 die Schritte des Drehmomentsteuerverfahrens für ein Elektro-Schlagwerkzeug mit einstellbarem Drehmoment gemäß der vorliegenden Erfindung,
• 6 Blockdiagramme verschiedener Ausführungsformen eines Drehmomentsteuersystems für ein Elektro-Schlagwerkzeug mit einstellbarem Drehmoment gemäß der vorliegenden Erfindung, bei dem Drehmoment über Spannungssteuerung gesteuert wird,
• 7, wie man die Übereinstimmungsbeziehungskurve von Spannung und Drehmoment modifiziert, die unter Verwendung der ersten Ausführungsform des Drehmomentsteuerverfahrens für ein Elektro-Schlagwerkzeug mit einstellbarem Drehmoment gemäß der vorliegenden Erfindung bestimmt wurde,
• die Figure 8A- 8E Strom-Ausgangsdrehmoment-Graphiken anhand experimenteller Beobachtungen gemäß einer zweiten Ausführungsform des Drehmomentsteuerverfahrens für ein Elektro-Schlagwerkzeug mit einstellbarem Drehmoment gemäß der vorliegenden Erfindung,
• 9 eine Beziehungskurve hoher bzw. niedriger Arbeitsströme und entsprechender gemessener hoher bzw. niedriger Drehmomente, die unter Verwendung der zweiten Ausführungsform des Drehmomentsteuerverfahrens für ein Elektro-Schlagwerkzeug mit einstellbarem Drehmoment gemäß der vorliegenden Erfindung erhalten werden, und
• 10 ein Blockdiagramm einer anderen Ausführungsform des Drehmomentsteuersystems für ein Elektro-Schlagwerkzeug mit einstellbarem Drehmoment gemäß der vorliegenden Erfindung, bei dem Drehmoment über Strom gesteuert wird.

The structure employed by the present invention and the technical means for achieving the above and other objects may best be understood by reference to the following detailed description of the preferred embodiments and the accompanying drawings. Show it:

• 1 conventional electric impact tools with adjustable torque with or without built-in torque measuring device,
• 2 various other adjustable torque electric impact tools with built-in or externally connected torque measuring device according to the present invention,
• the 3A - 3E Voltage output torque graphs based on experimental observations according to a first embodiment of a torque control method for an adjustable torque electric impact tool according to the present invention;
• 4 a relationship curve of high and low operating voltages and corresponding measured high and low torques respectively, which are obtained using the first embodiment of the torque control method for an adjustable-torque electric impact tool according to the present invention,
• 5 the steps of the torque control method for an adjustable torque electric impact tool according to the present invention;
• 6 Block diagrams of various embodiments of a torque control system for an adjustable torque electric impact tool according to the present invention Invention in which torque is controlled via voltage control,
• 7 How to Modify the Tension and Torque Match Relationship Curve Determined Using the First Embodiment of the Torque Control Method for an Adjustable Torque Electric Impact Tool according to the Present Invention
• Figure 8A-8E current output torque graphs from experimental observations according to a second embodiment of the torque control method for an adjustable torque electric impact tool according to the present invention;
• 9 a relationship curve of high and low operating currents and corresponding measured high and low torques, respectively, which are obtained using the second embodiment of the torque control method for an adjustable-torque electric impact tool according to the present invention, and
• 10 a block diagram of another embodiment of the torque control system for an adjustable-torque electric impact tool according to the present invention, in which the torque is controlled by current.

The present invention will now be described with reference to some preferred embodiments with reference to the accompanying drawings. For purposes of ease of understanding, elements that are the same in the preferred embodiments will be denoted by the same reference numerals.

It's up 2 Referring to Fig. 3, there are shown various adjustable torque electric percussion tools such as AC / DC powered power wrenches having a built-in torque measuring device or an externally connected torque measuring device in accordance with the present invention. In particular, in 2-1 a battery powered impact wrench is shown with externally connected torque measuring device, which generally with a reference numeral 2d " referred to, the battery powered impact wrench 2d out 1-1 similar but their torque measuring device 3 with an exit end 25 thereof is externally connected and internally a torque control device 21d " includes a socket wrench 4 and a bolt 5 to drive, which correspond to each other in type and size, via an exit end 25 the externally connected torque measuring device 3 to a workpiece 6 using the bolt 5 to tighten, as in the 6 and 10 is shown in 2-2 a battery powered impact wrench with built-in torque measuring device is shown, which generally with a reference numeral 2d '" referred to, the battery powered impact wrench 2d " out 2-1 similar, but with a built-in torque measuring device 24d ' in a housing thereof between an internal impact mechanism 23d ' and an exit end 25 is provided and internally a torque control device 21d '' includes a socket wrench 4 and a bolt 5 to drive, which correspond to each other in type and size, via an exit end 25 ' to a workpiece 6 using the bolt 5 tighten. In 2-3 a mains operated impact wrench with externally connected torque measuring device is shown, which generally with a reference numeral 2a " referred to, the mains operated impact wrench 2a out 1-3 similar but their torque measuring device 3 with an exit end 25 thereof is externally connected and internally a torque control device 21a " includes a socket wrench 4 and a bolt 5 to drive, which correspond to each other in type and size, via an exit end 25 ' the externally connected torque measuring device 3 to a workpiece 6 using the bolt 5 tighten. In 2-4 a mains operated impact wrench with built-in torque measuring device is shown, which generally with a reference numeral 2a '" referred to, the mains operated impact wrench 2a " out 2-3 similar, but with a built-in torque measuring device 24a ' in a housing thereof between an internal impact mechanism 23a ' and an exit end 25 is provided and internally a torque control device 21a '' includes a socket wrench 4 and a bolt 5 to drive, which correspond to each other in type and size, via an exit end 25 ' to a workpiece 6 using the bolt 5 tighten. According to the 2-1 to 2 - 4 include both battery-powered and mains powered adjustable-torque electric percussion tools, whether with an externally connected torque measuring device 3 or with a built-in torque measuring device 24d ' . 24a ' in that, in addition to the torque measuring device, a microprocessor wirelessly or wire-assisted continuously using the measurement signals transmitted continuously from the torque measuring device back to the torque control device during the tightening operation to perform the associated torque control or rotational speed control. By observing the pulse characteristics of the electric impact tools with the torque measuring device presented during the tightening process and the actual measured data, it is proved that a Torque control method for an adjustable-torque electric impact tool according to the present invention can definitely solve the problem of difficult tightening torque control which occurs in the conventional electric striking tools.

The 3A - 3E FIG. 12 is voltage output torque graphs based on experimental observations according to a first embodiment of a torque control method for an adjustable torque electric impact tool according to the present invention. FIG. The in the graphics from the 3A - 3E The data obtained is obtained by using the same adjustable torque electric impact tool with the same externally connected torque measuring device and by stably controlling the working voltage of the tool to be within a very small range of variation. The tool is driven by various voltages of 5V, 6V, 7V, 8V, 9V, 10V, 11V, 12V, 13V and 14V to separate the bolts of the same material and of the same size to tighten the workpieces with the same properties in the same exposure time. In all tightening operations driven by different voltage levels, measured torque values are relatively uniform and stable. Here only a part of the obtained graphics is taken and described. As in 4 4, an almost linear relationship between the high and low voltages and the corresponding measured high and low torque values, respectively, is presented. Based on the above theory and the experimental data, it is proved that, in the torque control method according to the present invention, one and the same adjustable torque electric power tool is driven by a stable working voltage in the manner of an adjustable torque electric impact driver, to tighten workpieces of the same tightening hardness during the same tightening time, similar tightening torque values can always be output. In other words, when using an adjustable torque electric wrench, for example, the tightening torque can always be controlled within a specific target area, provided that the variation in the percentage of working voltage throughout the tightening process is monitored and controlled to maintain the working voltage within a stable range of variation.

4 10 shows a relationship curve of high and low operating voltages and corresponding measured high and low torques, respectively, obtained using the first embodiment of the torque control method for an adjustable torque electric impact tool according to the present invention. The relationship curve in 4 is based on the actual measured data in the 3A - 3E plotted shown high and low torques. According to the characteristics of the adjustable torque electric percussion tools and the oil impulse torque tools, control parameters may be preset in the manner of the same tension and the same tightening time duration for one and the same tool. If the tool is operated in this way with a stable voltage that is monitored and controlled throughout the tightening process, the same torque can be stably output if the workpieces to be tightened have the same tightening hardness. For this purpose, first the highest tension VH and the lowest voltage VL of the tool during normal operation at its existing output capacitance detected. Then the highest tension VH and the lowest voltage VL used to drive the tool and its torque measuring device to perform a Drehmomentkalibriervorgang, so that the highest torque TH and the lowest torque TL obtained at the highest voltage and the lowest voltage, respectively. Thereafter, the linear regression is used to obtain a relationship curve of stress and torque LS using the highest voltage and the lowest voltage and the corresponding highest torque and the lowest torque. Accordingly, when a target torque value falls between the highest and lowest torque of the tool obtained from the above torque calibration operation, the microprocessor of the torque control apparatus according to the present invention immediately calculates for the adjustable torque electric impact tool based on the Tool stored voltage and torque match curve and automatically adjusts the tool to a corresponding working voltage to drive the tool to perform a tightening operation. Throughout the tightening process, the working voltage is continuously monitored and controlled to be maintained in a stable condition for performing the tightening operation. When the target torque value is reached, power to the tool is cut off and the operation of the adjustable torque electric shock tool is stopped. In this way, the output torque of the tool can be controlled within a preset allowable range. It is therefore no longer necessary to worry about the torque control accuracy being slowed down due to slow response Signal transmission between the torque control element and the torque measuring element can be influenced. However, the relationship between the calibrated torque values and the stresses can not be perfectly linear due to many factors such as the type of clearance between the socket / bolt and the workpiece, the way the tool is held, and the conditions of the workpiece to be tightened. In practical applications, the amount of deviation from the linear relationship curve, whether positive or negative, can be considered as a fundamental error in the torque control that can still be corrected to finally obtain the satisfactory torque control accuracy.

5 shows the steps of the torque control method for an adjustable torque electric impact tool according to the present invention. As shown, the torque control method according to the present invention comprises the following steps: ( S11 Connecting a power supply module to the adjustable torque electric shock tool and driving a torque measuring device installed in the tool or externally connected to an output end thereof for detecting the highest voltage VH and the lowest voltage VL of the tool under normal conditions at its existing output capacity, S12 ) Driving the tool and the torque measuring device and tightening a bolt against a workpiece to be tightened to perform a torque calibration operation and to determine a relationship curve of the highest and lowest voltages of the tool in normal operation and the corresponding highest and lowest torques, respectively ( S13 Inputting a target torque value falling between the highest and lowest torque values represented in the relational curve using a microprocessor of the torque control device for amplifying and calculating the input target torque value and comparing the input torque value with the relational curve previously stored in a storage unit; to obtain a working voltage corresponding to the target torque value for driving the adjustable torque electric impact tool and performing a tightening operation, and ( S14 ) Using measurement signals sent from the torque measuring device to the torque control device immediately and continuously, during the tightening process to perform the tightening operation under closed-loop torque control, and based on changes in voltage, current and motor temperature continuously from a voltage / current measuring element and a temperature measuring element of the torque control device, stable control of the working voltage within a preset allowable range of variation to control the tightening torque, by the microprocessor, and finally interrupting the power supply and issuing a warning when the range of the target Torque value has been reached.

Preferably, the torque control method for an adjustable torque electric impact tool according to the present invention may further comprise the steps of: using the torque measuring device according to the present invention or any other torque calibration tool to manually calibrate the highest and lowest torque values, respectively, the highest and lowest voltages inputting the respective calibrated highest and lowest torque values into the torque control device, using the voltage / current sensing element of the torque control device to obtain changes in voltage during the tightening process, and storing a kinetic relationship curve based on a plurality of groups average torque values obtained at a plurality of points in the process of torque calibration is determined in a storage unit of the Drehmomentsteuervorri rect.

Preferably, the torque control method for an adjustable torque electric shock tool according to the present invention may further include the steps of: depressing a calibration key in accordance with a preset auto-calibration mode so that the torque controller automatically detects the highest and lowest voltages of the tool during normal operation, respectively; co-operating with or externally connected to the output end thereof, to perform calibration of a plurality of sets of voltages and corresponding torque values at a plurality of points between the highest and lowest voltages, according to a preset program, to average sample data of multiple sets of voltages and corresponding torque values at several points to determine the relationship curve of the highest and lowest stresses of the tool, respectively, and then forming storing the relationship curve in a memory unit of the torque control device.

Preferably, the relationship curve may be finely adjusted or modified if the tightening torque does not meet the target torque value This is primarily because when determining the relationship curve of torque and high or low operating voltage of the adjustable torque tool, there is a difference between when calibrating used in relation to their hardness and a difference between the states of the bolts used, resulting in a relatively large error between the actually measured tightening torque value and the target torque value. In this case, the working voltage can be finely adjusted to modify the torque so that the tightening torque is closer to the target torque value. Therefore, in practice, the calibration of the relationship curve of high and low operating voltages and high and low output torques is preferably carried out on the basis of the actually to be tightened workpiece. Otherwise, it may be necessary to improve the control accuracy through a torque modification mode.

Preferably, a required torque modification can also be performed in the following situation. When an indicated actual torque value is in the vicinity of the target torque high or low limit, a torque modification key may be pressed for the microprocessor to automatically adjust the working voltage to be higher or lower along the relationship curve. Then, the adjustable torque electric shock tool is restarted, and a torque value even closer to the target torque value can be obtained. Otherwise, if there is a relatively large difference between the torque value detected by the customer's quality control (QC) personnel and the actual torque value displayed by the torque controller, both the displayed actual torque value and the detected torque value can have very good reproducibility and stability the torque modification key is pressed and held for about 1 second until a numeric keypad is displayed on a display unit of the torque control device. Then the torque value detected and approved by the customer must be entered and the ENTER key must be pressed. The microprocessor will automatically fine tune the working voltage higher or lower along the relationship curve. Then, the original target torque must be reentered and the adjustable torque electric shock tool started to perform the tightening operation. After the tightening process, the QC staff can recheck. In this way, the required torque control accuracy can be achieved.

Preferably, the torque control method for an adjustable torque electric impact tool according to the present invention may further include the steps of: adjusting the parameters related to the torque control before determining the above-mentioned relationship curve such as setting the highest working voltage to 90% or 95; % of a system detectable highest voltage value for use as the additional kinetic energy required in torque compensation. That is, when the tool achieves the target torque due to, for example, weakening the power output capability of the tool during the usage process or dropping the initial set torque caused by the temperature increase of the oil pulse from the hydraulic cylinder after continuous operation over a period of time or using the same torque setting For tightening workpieces of different tightening hardness or changing posture of a fatigued operator in handling the tool, after having worked for a long time, can not reach the target torque, the microprocessor of the torque control device can automatically adjust the working voltage higher along the relationship curve for the torque compensation and interrupts the power supply when the target torque has been reached, or outputs a warning via a display unit of the torque control device when the tension has been set to its highest or lowest limit, however, the tool still can not reach the target torque value.

Preferably, the torque control method for an adjustable torque electric impact tool according to the present invention may further comprise the steps of: monitoring and controlling the voltage changes throughout the tightening process, controlling and interrupting the power to the adjustable torque electric shock tool when the voltage change across one permissible range, and outputting a warning via a warning unit of the torque control device.

6 FIG. 12 shows block diagrams of various embodiments of a torque control system for an adjustable torque electric shock tool according to the present invention. FIG. According to these embodiments Tension used to control the torque of an adjustable torque electric impact tool. As shown, the torque control system according to the present invention includes a torque control device 21d " . 21d '" . 21a " . 21a '' between a power supply module 1 . 1' and an AC motor 22a or a DC motor 22d of the electric impact tool with adjustable torque is mounted. The torque control device 21d " . 21d '" . 21a " . 21a '" includes a microprocessor 211 and a voltage control module 212 , a voltage / current measuring element 213 , a temperature measuring element 214 , an analog-to-digital converter 215 , a communication module 216 , an input unit 217 , an output unit 218 , a display unit 219 , a warning unit 220 and a storage unit 221 that are electrically connected to the power supply module 1 . 1' via the microprocessor 211 connected to the AC / DC motor 22a . 22d drive. In 6-1 For example, the illustrated torque control system may be embodied in any one of a variable torque power tool with built-in torque measuring device, generally designated by a reference numeral 2a "' and an adjustable torque battery-operated impact tool with built-in torque measuring device, generally designated by a reference numeral 2d '" is applied, and includes a torque measuring device 24a ' . 24d ' which is mounted in a housing of the adjustable torque electric impact tool and located between an output end 25 a striking mechanism 23a ' . 23d ' and an output shaft 25 ' of the electric impact tool with adjustable torque is located. On the other hand, in 6-2 the illustrated torque control system to any one of an adjustable torque mains operated impact tool having an externally connected torque measuring device, generally designated by a reference numeral 2a " and an adjustable torque battery-operated impact tool having an externally connected torque measuring device, generally designated by a reference numeral 2d " is applied, and includes a torque measuring device 3 , which is externally connected to the tool and located between an output shaft 25 of the tool and a socket wrench 4 located. The built-in torque measuring device 24a ' . 24d ' and the externally connected torque measuring device 3 each comprise a torque measuring unit 32 , a power supply unit 33 and a printed circuit board module 31 , The PCB module 31 further comprises an amplification circuit unit 312 , a microprocessor 311 , an angle measuring unit 313 , a wire / wireless communication unit 314 and a storage unit 315 , In a torque calibration process for the tool, one must first torque the torque measurement unit 32 and the angle measuring unit 313 apply. A relationship curve between the deformation of the torque measuring unit 32 and the torque applied is in the memory unit 315 saved. In the process of tightening, the torque measuring device sends 24a ' . 24d ' instantaneous and continuous torque / angle measurement signals to the communication module 216 the torque control device 21d " . 21d '" . 21a " . 21a '' via the wire / wireless communication unit 314 , The microprocessor 211 The torque control device amplifies and calculates the received measurement signals and compares the signals with one in the memory unit 221 stored kinetic relationship curve to obtain a working voltage corresponding to a target torque value to perform the tightening operation under closed-loop torque control. During the tightening process, the voltage / current measuring element will detect 213 and the temperature measuring element 214 immediate and continuous voltage, current and temperature changes. Based on these detected changes, the microprocessor controls 211 stable via the voltage control module 212 the working voltage to keep it within a preset allowable range of variation to control the tightening torque. When the range of the target torque value is reached, the power source becomes 1 . 1' switched off, gives the warning unit 220 a warning and becomes a control result in the display unit 219 displayed.

The voltage control module 212 may be a pulse width modulation (PWM) controller that modulates and supplies a stable voltage to drive the motor, or it may be a proportional-integral-derivative (PID) controller that compensates the voltage according to an error amount, that is, the voltage increases or decreases in proportion to an existing error.

The microprocessors 211 . 311 may automatically adjust an initially determined voltage and torque match curve according to a modified torque value input by an operator after a torque calibration. Based on the modified voltage and torque match curve, the target torque value may be reentered to obtain a new working voltage.

The new working voltage is then used to drive the adjustable torque electric impact tool to perform a tightening operation.

If the tightening torque could not reach the target torque value or above the high or low limits of the allowable range of the target torque value, a fine adjustment or modification of the relationship curve can be performed. This is primarily because, when determining the relationship curve of torque and high or low working stress of the tool, there is a difference between the workpieces used in the calibration and the workpieces to be tightened in the actual tightening operation in terms of their hardness or between the states of the bolts used which would result in a relatively large error in the actual tightening torque value. In this case, the working voltage can be finely adjusted to modify the torque so that the tightening torque is closer to the target torque value. Therefore, in practice, the calibration of the relationship curve of torque and high or low working voltage is preferably carried out on the basis of the workpiece actually to be tightened. Otherwise, it may be necessary to improve the control accuracy through a torque modification mode. Preferably, a torque modification is performed in the following situation. If the indicated actual torque value is in the vicinity of the target torque high or low limit, a torque modification key may be pressed and the microprocessor will automatically adjust the working voltage to be higher or lower along the relationship curve Electric shock tool with adjustable torque restarted, and it can be obtained a torque value, which is even closer to the target torque value.

Otherwise, if there is a relatively large difference between the torque value detected by the customer's quality control (QC) personnel and the actual torque value displayed by the torque controller, both the displayed actual torque value and the detected torque value can have very good reproducibility and stability the microprocessor modifies the actual displayed torque value to be equal to the torque value measured by the QC personnel. At this point, the torque modification key must be pressed and held for about 1 second until a numeric keypad is displayed on the display unit of the torque control device. Then the torque value detected and approved by the customer must be entered and the ENTER key must be pressed. The microprocessor will automatically fine tune the working voltage higher or lower along the relationship curve. Then, the original target torque must be reentered and the adjustable torque electric shock tool started to perform the tightening operation. After the tightening process, the QC staff can recheck. In this way, the required torque control accuracy can be achieved.

According to the characteristics of the adjustable torque electric shock tools and the oil pulse torque tools, when using a second embodiment of the torque control system and method according to the present invention, operating conditions may be preset in the manner of the same current and tightening time for the same tool. If the tool is operated in this way with a stable current that is monitored and controlled throughout the tightening process, the same torque can be stably output when the workpieces to be tightened have the same hardness. For this purpose, during normal operation, the highest and lowest currents of the tool are detected at its existing output capacitance before the tightening operation is performed. Then, the tool and torque measuring device are driven to calibrate the highest and lowest tightening capacitances or torques respectively generated at the highest and lowest current levels to determine a relationship graph of current and corresponding torque. Thereafter, a target torque value that falls between the highest and lowest torque values on the relational curve is input to obtain a working current corresponding to the target torque value. The adjustable torque electric shock tool is then restarted to drive the torque measuring device built therein or externally connected to the output end thereof to perform a tightening operation. During the tightening process, the torque measuring device continuously sends torque / angle measurement signals to the torque control device. The microprocessor of the torque control device amplifies and calculates the received measurement signals and compares the signals with the relationship curve stored in the storage unit to find a duty value corresponding to the target torque value to perform the tightening operation under closed-loop torque control. During the tightening operation, the torque measuring device continuously transmits torque control device measurement information wirelessly or by wire, and the voltage / current measuring element and the temperature sensing element immediately and continuously detect voltage / current / temperature changes. Based on the measurement information and the detected voltage / current / Temperature changes, the microprocessor stably controls the operating current via a current control module to maintain it within a preset allowable range of variation to control the tightening torque. When the range of the target torque value is reached, the power supply is interrupted and a warning is issued. After the tightening operation has been performed, the tightening torque is recalibrated to check if it still falls within the preset range. If necessary, the aforementioned torque modification may be performed to more accurately control the tightening torque. Therefore, it is no longer necessary to develop an adjustable torque electric shock tool having a high accuracy manufacturing torque control mechanism. With the torque control system and method of the present invention alone, either the electric screwdriver or the torque adjustable oil pulse electric screwdriver can be used. to easily perform a more economical, reliable, efficient, and accurate tightening operation than any other conventional torque control technique.

7 Figure 4 shows how to modify the voltage and torque match curve of the torque control method of the present invention. It's up 7 along with 6 directed. An operator may use a frequently used or reliable torque calibration tool to calibrate the torque upon completion of the tightening operation. If it is between the torque value obtained from the calibration and the target torque value TX gives a relatively large difference, a MODIFY key (not shown) of the input unit 217 the torque control device 21d " . 21d " ' 21a " . 21a '' to enter the calibrated torque value and this in the memory unit 221 save. The microprocessor 211 becomes the coincidence relationship curve of stress and torque, which generally with LS is designated according to the modified torque value TX1 .automatically adjust. The adjusted voltage and torque matching curve is commonly used LM designated. Meanwhile, a new controllable torque range is set and displayed. In short, in the case where the inputted modified torque value becomes TX1 less than the target torque value TX is shifted down the adjusted match curve of tension and torque, as in 7 (a) is shown. On the other hand, if the inputted modified torque value TX1 greater than the target torque value TX is, the adjusted match curve of voltage and torque is shifted upward as in 7 (b) is shown. After the target torque value has been reentered, a new corresponding working voltage will be generated VX1 on the adjusted match curve of tension and torque LM receive. After the new working voltage VX1 for driving the battery powered impact wrench 2d " . 2d '' or the mains power wrench 2a " . 2a '" is used to perform the tightening operation, the calibration may be performed according to the actual need to check if a correct target torque value has been reached. Therefore, the torque control method according to the present invention not only accurately controls the output torque of the adjustable torque electric impact tool, but also satisfies the practical use requirements by allowing a user to fine tune torque by torque calibration according to various conditions of the workpieces to be joined ,

It should be noted that in the case where a voltage exceeding the preset allowable variation range is detected in the tightening process, a warning is promptly issued by the warning unit 220 the torque control device 21d " . 21d '' . 21a " . 21a '' is output or the power supply through the voltage control module 212 is interrupted until the voltage returns to the stable voltage range. At this point, the tightening process can continue. In addition, the adjustment of the allowable variation range is closely related to the accuracy of the torque value in the actual tightening operation. In short, the accuracy of the torque control is lower when a larger allowable variation range is set.

The 8A - 8E FIG. 12 is current output torque graphs based on experimental observations according to a second embodiment of the torque control method for an adjustable torque electric impact tool according to the present invention. FIG. In an experiment conducted by the inventor on the same adjustable torque electric impact wrench with the same externally connected torque measuring device, the operating current for driving the torque wrench is stably controlled to be within a very small variation range, and the torque wrench is operated using different amounts of current, including 12 A, 14 A, 16 A, 18 A, 20 A and 22 A, driven to tighten the bolts of the same material and of the same size separately on the workpieces with the same properties in the same exposure time. The results of the experiment indicate that the measured Output torques are relatively uniform and stable throughout the tightening operations. Here only a part of the obtained graphics is taken and described. As in the 8A - 8E and 9 On the basis of the above theory and the experimental data, it is proved that when in the torque control method according to the present invention, an almost linear relationship between the high and low currents and the corresponding measured high and low torque values, respectively and the same adjustable torque electric striker, such as an adjustable torque electric striker, is driven by a stable operating current to apply torque to workpieces of the same hardness during the same tightening time, similar tightening torque values can always be obtained. In other words, when using an adjustable torque electric power wrench, for example, the tightening torque can always be controlled within a specific target area, provided that the variation in the percentage of working flow throughout the tightening process is monitored and controlled to increase the working flow within a stable range of variation hold.

9 FIG. 10 shows a relationship graph of high and low operating currents and corresponding measured high and low torques, respectively, obtained using the second embodiment of the torque control method for an adjustable torque electric shock tool according to the present invention. The relationship curve in 9 is based on the actual measured data in the 8A - 8E plotted shown high and low torques. When using the adjustable torque electric percussion tools and the oil impulse torque tools, control parameters can be preset in the manner of the same tension and tightening time for one and the same tool. If the tool is operated in this way with a stable current that is monitored and controlled throughout the tightening process, the same torque can be stably output when the workpieces to be tightened have the same hardness. For this purpose, first the highest current IH and the lowest current IL of the tool during normal operation at its existing output capacitance detected. Then the tool and a torque measuring device are driven by it to get the highest torque TH and the lowest torque TL to drive each generated at the highest and the lowest current to drive. Thereafter, the linear regression is used to obtain a relationship graph of current and torque LS ' to determine. Accordingly, when a target torque value falling between the highest and lowest torque of the tool obtained from the above calibration is input, the microprocessor of the torque control apparatus according to the present invention immediately calculates on the basis of the adjustable torque power tool the current and torque match curve stored in the memory unit and automatically adjusts the tool to a corresponding working current to drive the tool to perform the tightening operation. Throughout the tightening process, the working voltage and the working current are monitored and controlled to maintain a stable current to perform the tightening operation. When the target torque value is reached, power to the tool is cut off and the operation of the adjustable torque electric shock tool is stopped. In this way, the output torque of the tool can be controlled and maintained within a preset allowable range. If, after tightening, there is a relatively large difference between the torque value obtained from the calibration and the target torque value TX The actual torque value can be determined using the same method previously described with reference to FIG 7 is adjusted to a value closest to the range of the target torque value.

10 FIG. 12 is a block diagram of another embodiment of the torque control system for an adjustable torque electric shock tool according to the present invention in which torque is controlled by current. This embodiment differs from the ones in FIG 6 illustrated embodiments in that the torque control device 21d " . 21d " ' 21a " . 21a '' a power control module 212 ' includes the voltage control module 212 replaced according to other embodiments. It has been proven that the torque control system according to the present invention with the power control module 212 ' can still achieve the same good torque control effect. However, considering some factors, including the technical difficulties and implementation costs, the use of voltage in torque control should still be the first choice.

The accuracy of the tool structure, manufacture and assembly has no absolute influence on the torque control. In general, neither the adjustment of the amount of current flowing through the tool nor the control of the duration of the exposure time can be other simple Tension control means achieve satisfactory effects in torque control. In particular, due to the generation of unstable pulse signal generation, it is not easy to detect the output torque of an adjustable-torque electric impact tool or an oil-pulse torque tool even when a torque measuring device is mounted on the tool. Torque control also becomes more difficult because all types of workpieces to be tightened and tightening elements to be used in tightening have many connection problems, including their materials, hardness and surface roughness, the treatment of bolted surfaces between them, the packaging material between the workpieces and the tightening elements, the structure the bonding surface and the bolt tightening sequence. The influence of all these problems on the accuracy of controlling the final tightening torque or the clamping force is much greater than the influence of the manufacturing quality or manufacturing accuracy of the tool.

The torque control system and method of the present invention overcomes the misconception on the part of manufacturers of conventional adjustable torque electric percussion tools that it is difficult to control the torque of that type of tool. The torque control system and method of the present invention are provided based on a thorough understanding of the characteristics of the relationship between the pulse signal and the torque of the adjustable torque electric shock tool or an oil pulse torque tool. The present invention has come to grips with the technique of detecting pulse signals to remove possible interference during transmission of electrical signals. In the torque control system and method for an adjustable torque electric impact tool according to the present invention, before starting a tightening operation, torque calibration is performed on the basis of the characteristics of the workpieces and the tightening elements to be used in the tightening operation. In the calibration, the torque control device is used to detect the highest and lowest operating voltages or currents of the tool during normal operation to obtain a kinetic relationship plot of highest or lowest working voltages or currents and corresponding highest and lowest torque values, respectively to determine. Then, a target torque value falling between the highest and lowest torque values may be input, and the microprocessor of the torque control device may find the exact operating current based on the previously determined relationship curve of working voltage and the corresponding tightening torque value to drive the tool and generate the target torque value. Then, the microprocessor automatically adjusts the working voltage or current and displays the adjusted working voltage or current on the display unit, thereby allowing the operator to perform the tightening operation with controllable output torque. Further, according to the present invention, changes in voltage and current, respectively, are monitored and controlled according to the preset operating and control conditions throughout the tightening process to thereby achieve accurate torque control.

Accurate torque control may be achieved for each adjustable torque electric impact tool, provided that the technical features and means defined by the torque control method and the torque control system according to the present invention are used accurately. As emphasized by the torque control method and system according to the present invention, a stable working voltage for operating the tool is always maintained throughout the tightening process. Further, based on the relationship curve of the highest or lowest voltage or current of the tool during normal operation and the corresponding highest and lowest tightening torque values, respectively, determined by torque calibration prior to the tightening operation, the operator may select a desired target torque value which falls within the range between the corresponding highest and lowest torque values to obtain a corresponding operating voltage or current for driving the adjustable torque electric impact tool and the torque measuring device built in or externally connected to the output end thereof to carry out the tightening process. During the tightening process, the microprocessor of the torque control device reminds the operator of the appropriate working voltage or current. Then, the voltage or current can be manually or automatically adjusted to the correct working voltage or current to drive the tool and perform the tightening operation. The accuracy of the tightening torque control can be adjusted according to the degree of accuracy actually required by adjusting the allowable variation range of the working voltage or the working current. The present invention also enables the user to modify the aforementioned voltage / current / torque relationship curve according to the actual torque value measured during calibration to perform the tightening operation with even more accurate torque control.

The present invention has been described in terms of some preferred embodiments, and it is to be understood that the preferred embodiments are for illustration only and are not intended to limit the invention in any way. Because the tightening torque of the adjustable torque electric screwdriver is indirectly proportional to the working voltage, the output torque can be controlled within a specific target range as long as the working voltage or current can be stably controlled throughout the tightening process within an allowable variation range. Therefore, while the torque control method according to the present invention has been described mainly from the viewpoint of voltage control, it should be understood that the description is illustrative and not restrictive and many changes and modifications can be made to the described embodiments without departing from the scope and spirit of the invention to depart, which are limited only by the appended claims.

LIST OF REFERENCE NUMBERS

1, 1 ')

Power supply module

2a, 2a ", 2a '")

numeral

2d, 2d ', 2d ", 2d'")

battery powered impact wrench

21a, 21a ', 21a ", 21a"')

Torque control device

21d, 21d ', 21d ", 21d'")

Torque control device

211)

microprocessor

212)

Voltage control module

212 ')

Power control module

213)

Voltage / current sensing element

214)

Temperature sensing element

215)

Analog to digital converter

216)

communication module

217)

input unit

218)

output unit

219)

display unit

220)

Wameinheit

221)

storage unit

22a, 22a ')

AC motor

22d, 22d ')

AC motor

23a, 23a ')

impact mechanism

23d, 23d ')

impact mechanism

24a, 24a ')

Torque measuring device

24d, 24d ')

Torque measuring device

25, 25 ')

output end

3)

Torque measuring device

31)

PCB module

311)

microprocessor

312)

Amplification circuit unit

313)

Angle measuring unit

314)

Wire / wireless communication unit

315)

storage unit

32)

Torque measuring unit

33)

Power supply unit

4)

Socket

5)

bolt

6)

workpiece

Claims (11)

A torque control method for an adjustable torque electric impact tool to be applied to a tightening operation performed using an adjustable torque electric power tool or an oil pulse torque tool, comprising the steps of: connecting a power supply module to an electric impact tool an adjustable torque built-in or externally connected to an output end thereof torque control device for outputting a stable working voltage for driving the electric impact torque adjustable tool and a torque measuring device installed in or externally connected to a torque motor tool, driving the electric adjustable torque striking tool and the torque measuring device using the highest working voltage and the lowest working voltage of the adjustable torque electric impacting tool under normal conditions to tightening torque calibration before starting the tightening process. Determining a match relationship curve of voltage and torque using the highest and lowest working voltages and the corresponding highest and lowest torque values obtained from the calibration operation, inputting a target torque value falling between the highest torque value and the lowest torque value based on the coincidence relationship curve of Tension and torque to obtain a corresponding working voltage, using the obtained corresponding operating voltage to drive the adjustable torque electric shock tool and the built-in or externally connected torque measuring device to perform the tightening operation, and using a microprocessor of the torque control device to immediately during the tightening process and amplify and calculate continuously transmitted from the torque measuring device to the torque control device measuring signals and the v and comparing measured signals with a kinetic relationship curve prestored in a memory unit of the torque control device to obtain a corresponding operating voltage for performing the tightening operation under closed-loop torque control, based on changes in voltage, current, and Temperature immediately and continuously detected by a voltage / current measuring element and a temperature measuring element of the torque control device, stable control of the working voltage within a preset allowable range of variation to control the tightening torque, via a voltage control module from the microprocessor, and finally switching off the power supply module and Issuing a warning when a range of the target torque value has been reached. Torque control method for an electric impact tool with adjustable torque to Claim 1 wherein the tightening torque calibration operation further comprises the steps of: using the adjustable torque electric shock tool to drive the torque measuring device during the tightening torque tightening torque process using the torque control device to detect the voltage signals detected by the voltage / current measuring element and the torque signals detected by the torque measuring device, storing the detected voltage signals and torque signals in the storage unit of the torque control device and performing the calibration of a plurality of groups of voltages and corresponding torque values at a plurality of points between the highest and the lowest voltage and obtaining average sampling data thereof for determining the coincidence relationship curve of voltages of the adjustable torque electric impact tool during normal operation and corresponding torque values. Torque control method for an electric impact tool with adjustable torque to Claim 1 further comprising the steps of: using the adjustable torque electric hammer tool to directly tighten a workpiece, and then using a torque calibration tool to obtain a torque value used to tighten or loosen the workpiece, inputting the torque value to the torque controller via a keyboard, storing the torque value in the storage unit of the torque control device, and performing the calibration of a plurality of groups of voltages and corresponding torque values at a plurality of points between the highest and the lowest voltage and obtaining from the inputted torque value and the voltages detected by the voltage / current measuring element of the torque control device during the entire tightening operation average sample data thereof for determining the coincidence relationship curve of voltages of the adjustable-torque electric impact tool in normal b operation and corresponding torque values. Torque control method for an electric impact tool with adjustable torque to Claim 2 and further comprising the steps of: automatically repeating the tightening torque calibration operation multiple times between the highest and lowest voltages according to a preset program for obtaining highest torque values and lowest torque values corresponding respectively to the plural groups of highest working voltages and lowest working voltages, combining and averaging multiple sets of highest torque values, lowest torque values, highest working voltages and lowest working voltages, and determining the voltage and torque match relationship curve using the obtained one average highest torque value, average lowest torque value, average highest working voltage, and average lowest working voltage, respectively. Torque control method for an electric impact tool with adjustable torque to Claim 3 and further comprising the steps of: automatically repeating the tightening torque calibration operation multiple times between the highest and lowest voltages according to a preset program for obtaining highest torque values and lowest torque values corresponding respectively to the plural groups of highest working voltages and lowest working voltages, combining and averaging multiple sets of highest torque values, lowest torque values, highest working voltages, and lowest working voltages, and determining the voltage and torque match relationship curve using the obtained average highest torque value, average lowest torque value, average highest working voltage, and average lowest working voltage, respectively. Torque control method for an electric impact tool with adjustable torque to Claim 1 further comprising the steps of: depressing a torque modifier key when there is a relatively large difference between the actual torque value and the target torque value, automatically adjusting the microprocessor's match voltage and torque relationship curve based on the modified torque value, and displaying an adjusted torque value controllable torque range, reentering the target torque value to obtain an adjusted operating voltage corresponding to the target torque value based on the adjusted torque and working voltage relationship curve, and using the adjusted operating voltage to drive the adjustable torque electric shock tool for execution the tightening operation so that the generated torque reaches the target range of the torque value. Torque control method for an electric impact tool with adjustable torque to Claim 1 further comprising the steps of: inputting a calibrated torque value to replace a displayed torque value, using the substitute torque value to replace the torque value initially shown in the voltage and torque match curve while the working voltage corresponding to the initially shown torque value remains unchanged; and reentering the target torque value and, based on the adjusted torque and working voltage relationship curve, driving the adjustable torque electric shock tool with the operating voltage to produce the desired target torque value in performing the tightening operation. Torque control method for an electric impact tool with adjustable torque to Claim 1 further comprising the steps of: if a calibrated torque value does not match the target torque value, but shows stable torque control reproducibility, modifying only the torque value of the relationship curve while leaving the curve unchanged, monitoring and controlling changes in voltage during the entire tightening process or the torque calibration and issuing a warning via a warning device or interrupting the power supply to the adjustable torque electric shock tool when a change in the voltage exceeds the allowable variation range. A torque control system for an adjustable torque electric impact tool comprising a power supply module and a torque control device electrically connected to the power supply module for driving an adjustable torque electric shock tool and a torque measuring device externally connected to a torque motor tool or externally connected to perform a tightening operation • wherein the torque control device comprises: • a microprocessor for immediately and continuously amplifying and calculating torque or angle measurement signals sent from the torque measurement device to the torque control device, comparing the amplified and calculated measurement signals to a relationship curve previously determined from a torque calibration process to obtain a working voltage corresponding to a target torque value for performing the tightening operation gs is closed-loop torque control, using the instantaneously and continuously detected changes in voltage, current, and temperature during the tightening process to stably control the working voltage within a preset allowable range of variation to control tightening torque and shutdown of Power supply module and outputting a warning when a range of the target torque value has been reached; a voltage control module for stably controlling the operating voltage within the preset torque control variation allowable tightening range using voltage, current, and temperature changes that occur immediately and continuously during the power supply module Tightening process; • a voltage / current measuring element for detecting working voltage and working current changes of the adjustable torque electric impacting tool during the tightening process and timely supplying the detected changes back to the microprocessor for use as a reference in voltage or current control; a temperature sensing element for detecting the increase in temperature of the adjustable torque electric shock tool and timely supplying the detected temperature rise back to the mic roprocessor for use as a reference in voltage or current control, • an input unit and an output unit for transmitting various torque settings in the torque control system, measured deformation values, target torque values, and torque control signals, • a display unit for displaying voltage and torque measuring units, target torque values and corresponding operating voltages, the number of tightening operations performed and conditions of tightening operations, • a warning unit for issuing warnings by light indicators or sounds to remind the user of each result of calculation and determination performed by the microprocessor, a wire / wireless communication module for data communication between the torque control device and the torque measurement device in a wired or wireless manner, and a memory unit for storing the highest operating voltage and lowest working voltage that are within a stable range of working voltages of the adjustable torque electric hammer tool in the normal tightening operation and used in a tightening torque calibration operation, and the corresponding highest torque value and the lowest torque value obtained from the tightening torque calibration operation; for storing other preset operating conditions; and • the torque measuring device incorporated in the adjustable torque electric impact tool or externally connected to an output end of the adjustable torque electric impact tool and a torque measuring unit and a printed circuit board module electrically connected to a battery unit , wherein the circuit board module further comprises a microprocessor, an amplification circuit unit, an angle measuring unit, a memory unit, an input / output comprising a charging circuit unit and a communication unit Torque control system for an electric impact tool with adjustable torque to Claim 9 wherein the tension control module is replaced by a flow control module, in which case the torque control device drives the adjustable torque electric shock tool and torque measuring device using the highest working flow and operating current of the adjustable torque electric shock tool in normal operation to provide tightening torque calibration prior to the start of the tightening operation, the current control module also determines a match relationship curve of current and torque using the highest and lowest operating currents and the corresponding highest and lowest torque values obtained from the calibration procedure, based on the current and torque match relationship curve, a target torque value; which falls between the highest torque value and the lowest torque value is input to obtain a corresponding operating current, the Torque control device used the obtained corresponding operating current for driving the torque-adjustable electric shock tool and the built-in or externally connected torque measuring device to perform the tightening operation, and the microprocessor of the torque control device during the tightening process immediately and continuously amplifies and calculates measured signals sent from the torque measuring device to the torque control device and comparing the amplified and calculated measurement signals with the relationship curve pre-stored in the storage unit of the torque control device to obtain a corresponding duty current for performing the tightening operation under closed-loop torque control, based on changes in voltage, current, and temperature immediately and continuously from the voltage / current measuring element and the temperature measuring element of the torque control device are detected, the microprocessor via the current control module stably controls the working current within a preset permissible range of variation to control the tightening torque, and finally the power to the adjustable torque electric shock tool is interrupted and a warning is output when the range of the target torque value has been reached. Torque control system for an electric impact tool with adjustable torque to Claim 9 wherein the torque controller microprocessor modifies and adjusts the current and torque match relationship curve based on an input modified torque value, wherein when the target torque value is reentered, a new corresponding operating current is displayed based on the adjusted current and torque matching relationship curve and the new corresponding operating current is used to drive the adjustable torque electric impact tool for the tool to produce a torque that is even closer to the target torque value when the tightening operation is performed.

Images