JP5245699B2 - Electric tool - Google Patents

Description

  The present invention relates to a power tool.

  As shown in FIG. 4, conventional rotary hammering tools include a hammer and anvil which are rotary hammering mechanisms 7, a spindle and planetary gears as a speed reduction mechanism 6, and a ring-shaped fixing fixed to the housing 2. There is a tool including a gear, a pinion, and a motor 4 as a driving unit.

  The structure is such that an electric motor 4 fixed in the housing 2, a fixed gear support jig, a fixed gear, a planetary gear, and a spindle supported with a rotation stopper in the housing 2 are arranged. An anvil is arranged, the spring is arranged between the planetary gear side of the spindle and the hammer, and the anvil can be connected to a tightening tip tool such as a cross screw driver bit or a hexagon bolt socket.

  The speed reduction mechanism 6 is composed of a pinion attached to the motor 4, a fixed gear, a planetary gear, and a needle pin supported by the spindle on the rotating shaft of the planetary gear. The planetary gear and the needle pin constitute a part of the spindle. doing. The spindle is rotatably supported by a center hole of an anvil having a rear end supported by a bearing and a front end supported by the bearing.

  The operation of generating a pulse-like rotational impact torque applied to the anvil is driven when the motor 4 to which power is supplied turns on the switch 5, and the power of the motor 4 is planetary via a pinion connected to the tip of the motor 4. Is transmitted to the gears. Since the planetary gear meshes with the fixed gear, the power of the pinion rotates the spindle through the needle pin, and the rotation of the spindle is brought into contact with the hammer through a ball disposed between the cam groove of the spindle and the cam groove of the hammer. introduce. The hammer is urged forward by a spring disposed between the hammer and the planetary gear portion of the spindle, and is pushed forward along the cam groove. After that, the hammer claw of the hammer with energy by spring force, rotation speed and moment of inertia hits the anvil claw of the anvil, so that the anvil is driven to rotate, and the bit connected to the anvil or the screw connected to the tip of the socket, Alternatively, torque is applied to the bolts and the wood or iron plate is tightened.

  Thereafter, when the hammer's impact energy decreases and the anvil torque decreases, the hammer repels from the anvil, and the hammer moves along the cam groove in the direction of the planetary gear. Thereafter, the hammer is pushed back along the cam groove again in the anvil direction by the compressive force of the spring, and the hammer is accelerated by the rotation of the spindle via a ball disposed between the cam groove of the spindle and the cam groove of the hammer. The spindle continues to rotate while the hammer reciprocates along the cam groove between the hammer and the stopper. Strike the anvil while rotating 180 °. In this way, by repeatedly hitting the anvil by axial movement and rotation of the hammer, a pulsed impact torque is continuously generated, and the screw or bolt is tightened.

  In this type of electric power tool, the hammer reciprocates in the axial direction to generate a striking force. Therefore, an elastic body 10 is provided at a fitting portion between the hammer case 8 that houses the hammer and the housing 2, and the hammer case 8 is vibrated. Is absorbed by the elastic body 10.

JP 2008-93782 A

  However, vibration is generated, and it is very difficult to eliminate the vibration at all. When considering effective utilization of electric power, it is a problem to use this vibration in reverse.

  When the motor is stopped by stopping the power supply from the normal rotation of the motor, that is, at the time of braking, a counter electromotive force is generated in the armature winding, and a regenerative braking brake is generated using this. Utilizing the generated power is also an issue when considering the effective use of power.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric tool that effectively uses the vibration generated during use and the counter electromotive force of the motor generated during braking.

  Another object of the present invention is to provide a mechanism capable of operating various electric devices provided in the electric tool independently of the use of the electric tool.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a motor that is provided with a supply cord from an external power source and is driven by the external power source, and has a main body body portion that accommodates the motor. In a power tool with a built-in hammer case, a tool protruding in front of the hammer case, and a switch trigger that drives the motor in the lower part of the hammer case in the main body body, a protruding portion at the bottom of the hammer case Is formed, a piezoelectric element is provided between the projecting portion provided on the main body body portion, a storage battery is further mounted, and electric power generated by the piezoelectric element is stored in the storage battery.

  The invention of claim 2 is characterized in that the electric power of the storage battery stored from the electric power of the piezoelectric element can be supplied to the LED light by a switch operation even in a state where no electric power is supplied from an external power source.

  The invention of claim 3 is characterized in that a piezoelectric element is provided between the hammer case and the anvil via a retaining ring.

  The invention of claim 4 is characterized in that an elastic body is provided between the main body body and the hammer case.

  The invention according to claim 5 is characterized in that regenerative electric power generated during braking of the motor of the electric tool is supplied to the storage battery according to claim 1.

  According to the present invention, due to vibration between the hammer case and the housing, a force is applied to the piezoelectric element to generate electric power, and the electric power generated by the piezoelectric element can be stored in the storage battery. Thereby, since electric power can be generated and stored while the main body is being used, electric power can be effectively used.

  In addition, as an effective use of the electric power generated from the piezoelectric element, the LED light can be turned on by a switch operation even in the absence of power supply from an external power source.

  In addition, since the anvil at the tip receives an impact in the axial direction by hitting, an impact force is applied to the piezoelectric element by attaching a C retaining ring to the anvil and providing a piezoelectric element with the hammer case, It is also possible to generate electricity.

  Furthermore, by interposing an elastic body between the hammer case and the housing, the housing and the hammer case do not behave in the same phase in the axial direction, so that a higher force can be applied to the piezoelectric element.

  Moreover, surplus electric power can be utilized effectively by storing the regenerative electric power which generate | occur | produces at the time of the brake of an electric tool in a storage battery.

  Moreover, in this invention, the apparatus which operate | moves independently of use of an electric tool can be driven by having provided the reserve battery in the electric tool. For example, an LED light, a liquid crystal clock, and a vibrometer can be installed to display the vibration on the liquid crystal, or equipped with a small radio, memory function and wireless transmission mechanism, so that music and weather information can be received via wireless earphones even during work. The battery can be used as a backup power source for these functions, such as a memory function for estimating and predicting the breakdown life based on the number of work, the usage time, and the applied vibration.

  An embodiment when the present invention is applied to the impact driver 1 will be described. An outline of the impact driver will be described with reference to FIG. The impact driver includes a housing 2 that forms an outer shell, a power cord 3 connected to the housing 2, a circuit 12 that converts AC power into DC, a DC motor 4 that is rotated by the power supplied from the power cord 3, and a DC motor 4 The switch 5 that controls the supply / stop of power to the motor, the speed reduction mechanism portion 6 that transmits the rotation of the DC motor 4, and the rotation transmitted from the speed reduction mechanism portion 6 are caused to hit by the rotary impact mechanism portion 7, and intermittent Can be hit hard and screws and bolts can be tightened. The speed reduction mechanism 6 and the rotary impact mechanism 7 are assembled in a hammer case 8 and assembled.

  In the embodiment of the present invention, as shown in FIGS. 1 and 2, a protruding portion 2 a is provided at the tip of the housing 2, and the protruding portion 8 a is also provided in the hammer case 8. A piezoelectric element 9 is provided between the two protruding portions. By doing so, a force is applied to the piezoelectric element 9 due to the vibration generated when the main body is used, so that it is possible to generate electric power by using the force.

  Since the hammer case 8 is fixed by the housing 2, even when vibration is applied, these two parts may move simultaneously. In that case, there is a possibility that less power is transmitted and less power is generated. Therefore, as shown in FIG. 2, the elastic body 10 is interposed between the hammer case 8 and the housing 2, so that the hammer case 8 and the housing 2 are axially moved when the elastic body 10 is crushed and vibrations are applied. Since the behavior does not become the same phase, a force can be applied to the piezoelectric element 9 more effectively, and the power generation efficiency can be improved.

  Further, a storage battery 23 is further mounted on the electric power tool 1, the electric power generated by the piezoelectric element 9 is stored in the storage battery 23, and even when there is no power supply from an external power source, as shown in FIG. The LED light 11 can be turned on.

  Moreover, if there is a difference in the axial behavior between the two parts even at other places, it is possible to generate electric power by providing the piezoelectric element 9. For example, as shown in FIG. 3, the anvil 14 at the tip 13 receives an impact in the axial direction due to impact, so a C retaining ring 15 is attached to the anvil and the piezoelectric element 9 is provided between the hammer case 8 and the anvil 14. Thus, it is possible to generate electric power by applying a shocking force to the piezoelectric element 9.

  Further, when the electric tool is braked, a large counter electromotive force is generated in the windings of the armature 4 and the motors (4, 16) function as a generator. This effect is utilized.

  Normally, as shown in FIG. 5A, during normal rotation of the motor, the main stator 22 is excited by the supply from the power source to generate a magnetic field, and the armature 4 rotates.

  However, at the time of braking, as shown in FIG. 5B, a back electromotive force is generated in the armature 4, a current flows through the stator brake coil 21, and a reverse magnetic field is generated, whereby the armature 4 gradually decelerates. . Here, a part of the counter electromotive force is also branched into the storage battery 23 and stored.

  Further, as shown in FIG. 6, in the case of a permanent magnet excitation type DC motor in which the motor stator main coil 22 and the brake coil 21 of FIG. 5 are replaced with permanent magnets 27, the back electromotive force of the armature 4 is a large-capacity resistance. 26, and it was very inefficient because it was converted into thermal energy of the resistor 26. By storing this back electromotive force in the storage battery 23, there is no power supply from an external power source. The LED light 11 can be turned on by operating the switch 24.

  In this embodiment, although the example of the electric tool provided with the piezoelectric element and the storage battery was shown, it is good also as a structure provided only with the storage battery, for example. That is, you may comprise so that a storage battery may be used as a reserve battery. Thereby, the apparatus which operate | moves independently of use of an electric tool can be driven by having provided the reserve battery in the electric tool. For example, an LED light, a liquid crystal clock, and a vibrometer can be installed to display the vibration on the liquid crystal, or equipped with a small radio, memory function and wireless transmission mechanism, so that music and weather information can be received via wireless earphones even during work. The storage battery can be used as a backup power source for these functions, such as a memory function for estimating and predicting the breakdown life based on the number of work, the number of working hours, and the applied vibration.

It is sectional drawing of the impact driver with a power cord of this invention. It is a detailed view (part A detail) of piezoelectric element fixation of the present invention. It is detail drawing of the piezoelectric element fixation of this invention. It is sectional drawing of the conventional impact driver. It is a schematic circuit diagram with a built-in storage battery of the impact driver with a power cord at the time of motor forward rotation. It is a schematic circuit diagram with a built-in storage battery of the impact driver with a power cord at the time of motor braking. It is a schematic circuit diagram with a built-in storage battery of a permanent magnet excitation type DC motor of an impact driver with a power cord.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Impact driver 2 ... Housing 2a ... Projection part 3 of housing ... Power cord 4 ... DC motor 5 ... Switch 6 ... Deceleration mechanism part 7 ... Rotary impact mechanism part 8 ... Hammer case 8a ... Projection part 9 of hammer case ... Piezoelectric element 10 ... elastic body 11 ... LED light 12 ... circuit 13 ... tip 14 ... anvil 15 ... C retaining ring 16 ... stator or magnet type 20 ... motor armature 21 ... motor stator brake coil 22 ... motor stator main coil 23 ... storage battery 24 ... LED switch 25 ... AC to DC conversion circuit 26 ... resistor 27 ... permanent magnet

Claims (5)

Provided with a cord for supplying power from an external power source and having a motor driven by the external power source, a main body body portion for housing the motor, a hammer case incorporating a striking mechanism is assembled, and a tool is placed in front of the hammer case In a power tool provided with a switch trigger for driving the motor at a position below the hammer case in the main body body portion, a protrusion portion is formed at the lower portion of the hammer case, and the protrusion provided on the main body body portion. A power tool characterized in that a piezoelectric element is provided between a mounting portion and a storage battery, and further, a storage battery is mounted, and electric power generated by the piezoelectric element can be stored in the storage battery. 2. The electric tool according to claim 1, wherein the electric power of the storage battery stored from the electric power of the piezoelectric element can be supplied to the LED light by a switch operation even in a state where no electric power is supplied from an external power source. The electric tool according to claim 1 or 2, wherein a piezoelectric element is provided between the hammer case and the anvil via a retaining ring. The electric tool according to any one of claims 1 to 3, wherein an elastic body is provided between the main body body and the hammer case. The power tool according to any one of claims 1 to 4, wherein regenerative electric power generated during braking of the motor of the power tool is supplied to the storage battery.

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