TWM587406U - Electric impact tool control system capable of maintaining equal tightness - Google Patents

Abstract

The new type is an electric impact tool control system capable of maintaining the same tightness, including: a current detection circuit to detect a load current signal; a first filter circuit electrically connected to the current detection circuit and filtering the load current Signal; an amplifier circuit electrically connected to the first filter circuit to amplify the load current signal; a second filter circuit electrically connected to the amplifier circuit to filter the load current signal; a band-pass filter circuit to electrically The second filter circuit is connected to filter the noise of the load current signal; a waveform conversion circuit is electrically connected to the band-pass filter circuit to convert the load current signal into a square wave; a central processing unit A unit that is electrically connected to the second filter circuit and the waveform conversion circuit, and presets a fixed current and a preset number of strokes; the central processing unit is used to output a stable torque and the same number of strokes, so that locking components such as screws are fixed Can be locked with the same tightness.

Description

Electric impact tool control system capable of maintaining the same tightness

An electric impact tool control system, particularly an electric impact tool control system that can maintain the same tightness.

For the construction workers of the project, in order to fix the workpiece, screws, nuts, nuts, bolts and other large and small locking parts are often used. In general, if there is furniture that needs to be disassembled, there are opportunities to remove the screws. Whether disassembling or disassembling large workpieces or small tools and equipment, in order to make the disassembly and assembly process more convenient, manual screwdrivers are often used to tighten / unscrew the screws.

The existing electric / pneumatic tools, such as electric screwdrivers, are more convenient than manual screwdrivers. Users only need to hold the electric screwdriver and put the screwdriver head into the screw hole, then press the start button of the electric screwdriver. The electric screwdriver is It will automatically drive the screw to lock or loosen. The user does not need to rotate the screwdriver by hand, which is more convenient to use.

However, the existing electric / pneumatic tools fail to check whether the screw is really tightened when locking the screw. The staff must lock the screw by feeling. When the screw cannot be further locked, the screw will be determined by itself. Therefore, if the staff member feels wrong, the unfastened screws are judged to be locked, resulting in insufficient structural connection strength, and subsequent accidents and accidents are likely to occur.

In addition, if the staff is worried that the screw lock is not tight enough and repeatedly locks, increasing the number of blows, it will also cause the screw to bear more than the load, causing the screw to be injured and the strength reduced, which may also affect the stability of the structure.

In order to ensure that the locking parts such as screws and nuts can be locked securely, the new model proposes an electric impact tool control system that can maintain the same tightness. The central processing unit unified the number of blows and outputs a stable locking torque to make The tightness of each locking component is maintained to maintain structural strength and maintain the integrity of the component.

In order to achieve the above purpose, the novel electric impact tool control system capable of maintaining the same tightness includes:
A current detection circuit for detecting a load current signal, wherein the load current signal is a current driven by an electric impact tool to rotate a head cap;
A first filter circuit electrically connected to the current detection circuit for filtering the load current signal to obtain a first stable current signal;
An amplifier circuit electrically connected to the first filter circuit for amplifying the first stable current signal to generate an amplified current signal;
A second filter circuit electrically connected to the amplifier circuit for filtering the amplified current signal again to obtain a second stable current signal;
A band-pass filter circuit electrically connected to the second filter circuit for filtering noise of the amplified current signal and generating an output current signal;
A waveform conversion circuit electrically connected to the band-pass filter circuit for converting the output current signal into a square wave current signal, wherein the square wave current signal represents the actual number of strikes;
A central processing unit is electrically connected to the second filter circuit and the waveform conversion circuit, and presets a fixed current signal and a preset number of strikes; the central processing unit adjusts the second stable current signal and the fixed current signal Similarly, to control the screwdriver head cap to output a stable torque, and when it is determined that the actual number of blows reaches the preset number of blows, stop driving the screwdriver head cap to rotate.

The novel type adopts the second filter circuit and the current detector of the central processing unit to fix the torque output, and uses the waveform conversion circuit to convert the output current signal into the square wave current signal, and the actual processing is controlled by the central processing unit. The number of blows is consistent with the preset number of blows. On the one hand, the parts are kept under the same force, and the structural strength will not be reduced due to the excessive force on some parts. Prevent the staff from feeling the tightness of the locking parts to make the tightness error, affecting the structural strength.

Please refer to FIG. 1, the present invention provides an electric impact tool control system capable of maintaining the same tightness, which is applied to the electric impact tool 80 shown in FIG. 1, and is controlled when using a head cap locking screw, a nut and the like The rotation torque and the number of hits are the same, and the tightness of the part locking is unified.

Please refer to FIG. 2. The electric shock tool control system of the new type which can maintain the same tightness includes: a current detection circuit 10, a first filter circuit 20, an amplifier circuit 30, a second filter circuit 40, and a band-pass filter. The circuit 50 and a waveform conversion circuit 60. The first filter circuit 20 is electrically connected to the current detection circuit 10; the amplifier circuit 30 is electrically connected to the first filter circuit 20; the second filter circuit 40 is electrically connected to the amplifier circuit 30; the band-pass filter The circuit 50 is electrically connected to the second filter circuit 40; the waveform conversion circuit 60 is electrically connected to the band-pass filter circuit 50.

In the following, the preferred embodiments and operation modes of the circuits are described in order.

Referring to FIG. 2 and FIG. 3A, the current detection circuit 10 is used to receive a load current signal and detect the load current signal, wherein the load current signal is generated by resistance encountered by the electric impact tool, such as when a screw lock The tighter it is, the harder the screwdriver head cap of the electric impact tool is to turn, and the load current signal is larger at this time; if the screw is to be loosened, the easier the screw head cap of the electric impact tool is to turn, the load current The signal is small. FIG. 3A is a waveform diagram of a load current signal. As shown in FIG. 3A, the load current signal has a large fluctuation. In a preferred embodiment of the present invention, the current detection circuit 10 includes two first resistors R1 and a second resistor R2 connected in parallel with each other, wherein the first resistor R1 and the second resistor R2 may be relatively small in resistance. Small resistance.

Referring to FIG. 2 and FIG. 3B, the first filter circuit 20 receives the load current signal and filters the load current signal to obtain a relatively stable first stable current signal. FIG. 3B is a waveform diagram of the first stable current signal. As shown in FIG. 3B, the waveform of the first stable current signal is relatively flat. In the preferred embodiment of the present invention, the first filter circuit 20 includes a resistor and two first capacitors C1 and a second capacitor C2 connected in parallel with each other.

Referring to FIG. 2 and FIG. 3C, the amplifier circuit 30 is configured to receive the first stable current signal and amplify the first stable current signal to generate an amplified current signal. FIG. 3C is a waveform diagram of the amplified current signal. As shown in FIG. 3C, the amplified current signal is significantly larger than the stable current signal. In the preferred embodiment of the present invention, the amplifier circuit 30 includes a first amplifier 31, a third capacitor C3, a third resistor R3, and a fourth resistor R4. The non-inverting input terminal of the first amplifier 31 is electrically connected to the first filter circuit 20, and the inverting input terminal of the first amplifier 31 is electrically connected to the fourth resistor R4 and grounded; the third capacitor C3 is electrically Connected to the inverting input terminal and output terminal of the first amplifier 31; the third resistor R3 is connected in parallel with the third capacitor C3. The first stable current signal can be amplified to the amplified current signal suitable for a 0-5V circuit by using the combination of the above-mentioned amplifier, capacitor and resistor.

The second filtering circuit 40 is configured to filter the amplified current signal again to obtain a second stable current signal. The second filtering circuit 40 may be further electrically connected to a central processing unit 91, and transmit the second stable current signal to the central processing unit 91, and a current signal detector of the central processing unit 91 detects the first Two stable current signals. In the preferred embodiment of the present invention, the second filter circuit 40 includes two fourth capacitors C4 and a fifth capacitor C5 connected in parallel with each other. One end of the fourth capacitor C4 is connected in series with a resistor and connected to the amplifier circuit 30. , The other end is grounded; one end of the fifth capacitor C5 is further connected to the central processing unit 91.

Furthermore, in order to fix the torque output during striking, the central processing unit 91 presets a fixed current. When the second stable current signal is smaller than the fixed current, the central processing unit 91 controls to increase the second stable current signal to the The fixed current enables the electric impact tool control system that can maintain the same tightness to fix the torque output when hitting, so that the hitting force is the same every time. The strike force can be adjusted by the user, and the strike force can be adjusted as required.

Please refer to FIG. 2 and FIG. 3E. The band-pass filter circuit 50 is configured to filter out signals with too high or too low frequencies in the second stable current signal, and generate an output current signal. The trough values are all at the same level. FIG. 3E is a waveform diagram of the second stable current signal. As shown in FIG. 3E, the second stable current signal has been removed from signals with too high and too low frequencies. In the preferred embodiment of the present invention, the band-pass filter circuit 50 includes a seventh capacitor C7, an eighth capacitor C8, and a sixth resistor R6. One end of the seventh capacitor C7 is electrically connected to the amplifier circuit 30 and the filter circuit 40; the sixth resistor R6 is connected in parallel with the eighth capacitor C8 and then connected in series with the other end of the seventh capacitor C7.

Please refer to FIG. 2 and FIG. 3D. In a preferred embodiment of the present invention, a third filter circuit 70 may be further included. The third filter circuit 70 is electrically connected to the amplifier circuit 30 and the band-pass filter circuit 50. FIG. 3D is a waveform diagram of the amplified current signal being filtered again. The third filtering circuit 70 may include a fifth resistor R5 and a sixth capacitor C6. One end of the fifth resistor R5 is connected to the first amplifier 31. The output end is electrically connected, and the other end is electrically connected to one end of the sixth capacitor C6; the other end of the sixth capacitor C6 is grounded. Through the third filtering circuit 70, the amplified current signal can be filtered again to obtain the second stable current signal which is smoother and no noise. In FIG. 3D, the waveform diagrams of the amplified current signal of two different sizes above and below are again filtered, which means that whether it is a high current or low current signal, it will be filtered to the same after filtering through the bandpass filter circuit 50. Follow-up judgment is performed on the level; the filtered result is shown in Figure 3E.

Referring to FIG. 2 and FIG. 3F, the waveform conversion circuit 60 is used to convert the output current signal into a square wave current signal, so that the output current signal is converted from a sine wave form to a square wave form. The waveform conversion circuit 60 inputs the square wave current signal to the central processing unit 91, and a strike counting detector of the central processing unit 91 detects the number of peaks in the square wave current signal. FIG. 3F is a waveform diagram of converting the output current signal into the square wave current signal. As shown in FIG. 3F, the peak value of the output current signal is sampled as the square wave current signal peak 63. Wherein, the waveform conversion circuit 60 presets a strike threshold. When the output current signal is higher than the strike threshold, the waveform conversion circuit 60 samples the output current signal to a high level; the output current signal is lower than the strike threshold. At this time, the waveform conversion circuit 60 samples the output current signal to a low level, forms the square wave current signal from the high level and the low level, and inputs the square wave current signal to the central processing unit 91.

In the preferred embodiment of the present invention, the waveform conversion circuit 60 is a Schmitt trigger circuit and includes a second amplifier 61, a ninth capacitor C9, a tenth capacitor C10, a seventh resistor R7, a An eighth resistor R8 and a ninth resistor R9. The inverting input terminal of the second amplifier 61 is connected to the band-pass filter circuit 50, and the non-inverting input terminal is connected to the ninth resistor R9 and grounded; the ninth capacitor C9 is connected to the power input terminal of the second amplifier 61 and grounded. Between; the eighth resistor R8 is connected to the output of the second amplifier 61 and the ninth resistor R9; the seventh resistor R7 is connected to the output of the second amplifier 61 and further connected to the central processing unit 91; the first One end of the ten capacitor C10 is connected to the seventh resistor R7 and the central processing unit 91, and the other end is grounded.

The hit count detector of the central processing unit 91 determines the actual number of hits according to the number of high levels in the square wave current signal, where the number of high levels is equal to the actual number of hits.

The central processing unit 91 also presets a preset number of strikes. When the strike count detector determines that the current number of strikes is the same as the preset number of strikes, the new electric shock tool control system that can maintain the same tightness controls the The screwdriver cap stops rotating. The preset number of blows can be adjusted by the user.

Furthermore, the present invention has a current compensation mode. When the battery power of the electric impact tool 80 is insufficient to reduce the voltage, in order to maintain a fixed output power to provide a fixed torque output, the central processing unit 91 executes the current compensation mode to control the load current signal to increase when the voltage drops When the output current is increased to maintain the same power, the torque output can be fixed. When the battery power is insufficient, parts such as screws can still be locked with the same tightness. In a preferred embodiment of the present invention, the central processing unit 91 uses pulse width modulation (PWM) to increase the load current signal.

Referring to FIG. 4, a display interface 81 may be provided on the appearance of the novel model. The display interface 81 includes a first button 82, a second button 83, a third button 84, a plurality of display lights 85, and a plurality of seven segments. Display 86. The first button 82, the second button 83, the third button 84, the plurality of display lamps 85, and the plurality of seven-segment displays 86 are all electrically connected to the central control unit 91, wherein the first button 82 is switchable Each set value is displayed by the plural seven-segment display 86; the second button 83 can switch different functions, such as setting the striking strength, setting the number of striking times, and setting the number of floating lock cycles; the third button 84 can confirm the entered setting value . The plurality of display lights 85 can display different colors and quantities according to the current state of the electric impact tool control system that can maintain the same tightness.

The present invention uses the second filter circuit 40 to transmit the collated second stable current signal to the current detector, and the central processing unit 91 controls the second stable current signal to maintain the same value as the fixed current to ensure that The torque output is consistent; at the same time, the output current signal is converted into the square wave current signal by the waveform conversion circuit 60, and the actual number of blows is judged by the blow count detector, and the actual blow is controlled by the central processing unit 91 The number of times is the same as the preset number of strikes. By the above-mentioned technical means of controlling the number of blows and controlling the current output, it is ensured that each screw and other parts can be locked with the same tightness, and the connection strength of the workpiece is improved.

10‧‧‧Current detection circuit

20‧‧‧first filter circuit
30‧‧‧amplified circuit

31‧‧‧The first amplifier
40‧‧‧second filter circuit

50‧‧‧Band Pass Filter Circuit
60‧‧‧Waveform conversion circuit

61‧‧‧Second Amplifier
63‧‧‧Square wave current signal peak

70‧‧‧third filter circuit
80‧‧‧ Electric Impact Tools

81‧‧‧display interface
82‧‧‧first button

83‧‧‧Second button
84‧‧‧Third button

85‧‧‧ display light
86‧‧‧Seven-segment display

91‧‧‧ Central Processing Unit
R1 ~ R9‧‧‧first ~ ninth resistor

C1 ~ C10‧‧‧First ~ Tenth Capacitors         

Figure 1: Schematic diagram of the three-dimensional appearance of the new model.
Figure 2: Schematic diagram of the circuit structure of the new model.
Fig. 3A ~ Fig. 3F: Schematic diagram of current waveform of this new model.
Figure 4: Schematic plan view of the operating interface of the new model.

Claims (10)

An electric impact tool control system capable of maintaining the same tightness, including:
A current detection circuit for detecting a load current signal, wherein the load current signal is a current driven by an electric impact tool to rotate a head cap;
A first filter circuit electrically connected to the current detection circuit for filtering the load current signal to obtain a first stable current signal;
An amplifier circuit electrically connected to the first filter circuit for amplifying the first stable current signal to generate an amplified current signal;
A second filter circuit electrically connected to the amplifier circuit for filtering the amplified current signal again to obtain a second stable current signal;
A band-pass filter circuit electrically connected to the second filter circuit for filtering noise of the amplified current signal and generating an output current signal;
A waveform conversion circuit electrically connected to the band-pass filter circuit for converting the output current signal into a square wave current signal, wherein the square wave current signal represents the actual number of strikes;
A central processing unit is electrically connected to the second filter circuit and the waveform conversion circuit, and presets a fixed current signal and a preset number of strikes; the central processing unit adjusts the second stable current signal and the fixed current signal Similarly, to control the screwdriver head cap to output a stable torque, and when it is determined that the actual number of blows reaches the preset number of blows, stop driving the screwdriver head cap to rotate. The electric impact tool control system capable of maintaining the same tightness as described in claim 1, wherein the central processing unit includes:
A current signal detector for detecting the second stable current signal;
A strike number detector is used to detect the number of peaks in the square wave current signal, wherein the number of peaks in the square wave current signal represents the actual number of strikes. The electric impact tool control system capable of maintaining the same tightness as described in claim 2, further including a third filter circuit, which is electrically connected to the amplifier circuit and the band-pass filter circuit to further filter the Amplify the current signal. As described in claim 3, the electric impact tool control system capable of maintaining the same tightness further includes a current compensation mode. When the battery power of the electric impact tool control system capable of maintaining the same tightness is insufficient, the central processing unit executes the In current compensation mode, increase the load current signal. As described in claim 4, the electric shock tool control system capable of maintaining the same tightness, the central processing unit uses pulse width modulation technology to increase the load current signal. As described in claim 5, the electric impact tool control system capable of maintaining the same tightness, the current detection circuit includes two first resistors and a second resistor connected in parallel with each other. The electric impact tool control system capable of maintaining the same tightness as described in claim 6, the filter circuit includes a resistor and two first capacitors and a second capacitor connected in parallel with each other. The electric impact tool control system capable of maintaining the same tightness as described in claim 7, the amplifying circuit includes a first amplifier, a third capacitor, a third resistor, and a fourth resistor; the non-inverting of the first amplifier The input terminal is electrically connected to the first filter circuit, the inverting input terminal of the first amplifier is electrically connected to the fourth resistor, and the third capacitor is electrically connected to the inverting input terminal and the output terminal of the first amplifier. ; The third resistor is connected in parallel with the third capacitor. The electric impact tool control system capable of maintaining the same tightness as described in claim 8, the second filter circuit includes two fourth capacitors and a fifth capacitor connected in parallel with each other, and one end of the fourth capacitor is connected in series with a resistor The other end of the amplifying circuit is grounded; one end of the fifth capacitor is further connected to the central processing unit. The electric impact tool control system capable of maintaining the same tightness as described in claim 9, the waveform conversion circuit is a Schmitt trigger circuit, and includes a second amplifier, a ninth capacitor, a tenth capacitor, and a seventh Resistor, an eighth resistor, and a ninth resistor; the inverting input of the second amplifier is connected to the band-pass filter circuit, and the non-inverting input is connected to the ninth resistor and grounded; the ninth capacitor is connected to the second Between the power input terminal of the amplifier and ground; the eighth resistor is connected to the output terminal of the second amplifier and the ninth resistor; the seventh resistor is connected to the output terminal of the second amplifier and further connected to the central processing unit; One end of the tenth capacitor is connected to the seventh resistor and the central processing unit, and the other end is grounded.