JP2007111778A - Screw driver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw driver which has a driving section driven by external power source fed via a power source section, wherein the screw driver can hold screws for use in screwing, without provision of a connection screws, thereby facilitating handling of the screw, and facilitates detachment of the screws and a tool held by the screw driver when the driver is not used or left stored. <P>SOLUTION: The screw driver is formed of the power source section to which external power source is fed, the driving section driven by the external power source fed from the power source section, a screwing tool mounting section 3 rotationally operated by the driving section, and an electromagnetic section 6 excited by the power source fed from the power source section. The electromagnetic section 6 is set on one or both sides of an external casing 1 where the driving section is housed, and when excited by the power source fed from the power source section, the electromagnetic section 6 adsorbs the screws 7 which are to be attached to the screwing tool 2 mounted on the screwing tool mounting section 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a screw driver that can be used for screw tightening or unscrewing, and more particularly to a board screw driver.

  Conventionally, a screw driver having a drive unit that is driven by being supplied with an external power supply via a power supply unit has been proposed. The drive unit rotates the screw tightening tool mounting portion to which the screw tightening tool is mounted. In this screw driver, by screwing a screw tightening tool (bit) to the screw tightening tool mounting portion, it is possible to perform screw tightening or screw removal at high speed.

  Conventionally, handling of screws used for screw tightening using such a screw driver has been complicated. That is, since the conventional screw driver does not have a function to store the screw, the operator puts the screw in the tool bag or case attached to the pocket of the work jacket or the waist belt, or A method is generally used in which a screw is put in the mouth, and the screw is taken out and tightened when necessary. However, to remove the screw from the jacket pocket, etc., it is troublesome because the arm must be moved a lot, and if the number of screws increases, it will take more work, and put your hands in the pocket etc. In some cases, the fingertip may be injured with a screw. In addition, putting a screw in the mouth is dangerous because it may cause injury to the mouth and is not preferable in terms of hygiene.

  Moreover, when the line of sight is aligned with the work location, when the screw in the pocket or the like is taken out, the line of sight may move from the work location to the pocket or the like. In this case, the line of sight is adjusted to the work location again. If the work is an upward work, it is accompanied by an operation of shaking the head up and down, resulting in a decrease in work efficiency and physical pain. For this reason, it is more efficient to put a screw in the mouth than a pocket or the like, and the risk of injury to the mouth and the problem of hygiene are further promoted. Note that board screwdrivers are often used in upward work.

  Further, the screw tightening work may be a continuous work of drilling and screw tightening, such as drilling a board such as a ceiling and then tightening the screw. In this case, it is necessary to replace the drilling tool (bite) and screw tightening tool (bit) with the screwdriver in order, and it is also necessary to remove the bite and bit from the case or tool bag attached to the waist belt. It becomes.

  Conventionally, as described in Patent Document 1, a configuration has been proposed in which a permanent magnet is attached to an outer casing of a screw driver, and a screw or a tool is attracted to the permanent magnet.

  Further, there has been proposed a screw driver that uses a connecting screw to which a plurality of screws are connected, so that the screws forming the connecting screw can be sequentially supplied to a screw tightening tool.

JP 2004-306221 A

  By the way, in the screw driver described in patent document 1, since the screw and the tool are attracted by the permanent magnet, the screw and the tool are always attracted, and these are used when the screw driver is not used or stored. It is difficult to pull the screw or tool away from the permanent magnet. Therefore, as the permanent magnet, a magnet that exhibits a very strong magnetic force cannot be used, and therefore the number of screws that can be attracted is limited.

  And in the screwdriver which used the connection screw, since the kind of screw which can be used will be limited and the price of a screw will also become high, there exists a limit in the spread.

  The present invention is proposed in view of the above-described circumstances, and is used for screw tightening without using a connecting screw in a screw driver having a drive unit that is driven by being supplied with an external power supply via a power supply unit. A screwdriver that makes it easy to handle the screw by holding it, and makes it easy to remove the screw and tool from the holding state when the screwdriver is not used or stored. Is to provide.

  In order to solve the above-described problems, a screw driver according to the present invention has the following configuration.

  That is, the screw driver according to the present invention includes a power supply unit to which external power is supplied, a drive unit that is driven by being supplied with drive power from the power supply unit, and a screw tightening tool mounting unit that is rotated by the drive unit. And an electromagnet unit that is energized by being supplied with power from the power source unit, and the electromagnet unit is installed on one side or both sides of the outer casing that houses the drive unit, and is supplied with power from the power source unit. When the magnet is excited, the screw mounted on the screw tightening tool attached to the screw tightening tool mounting portion is attracted.

  Note that the electromagnet portion can attract a drilling tool and the like in addition to the screw when the power is supplied from the power supply portion and is excited. In this case, tool change during operations from drilling to screw tightening can be performed quickly.

  In the screw driver according to the present invention, when the electromagnet unit is excited by being supplied with power from the power source unit, the screw used for screw tightening is attracted and held, so that the arm can be used without using a connecting screw. The screw can be taken out and removed only by moving the screw a little, so that it is possible to omit the work of putting the screw in and out of the mouth and the like, and the handling of the screw is facilitated, and the work time for screw tightening and screw removal can be shortened.

  In other words, with the work location still in view, the screw attracted to the electromagnet installed on one or both sides of the outer casing of the screwdriver is carried to the work location, and vice versa. Therefore, it is possible to easily attract the screw removed from the electromagnet to the electromagnet, and it is possible to hardly move the line of sight, and it is possible to shorten the time for screw tightening and screw removal work. And when working upwards, it is possible to reduce the physical burden because the neck is hardly moved, and even when working in places with poor scaffolding, safety is improved by shortening the work time. Can do. Therefore, the present invention is particularly suitable when applied to a board screwdriver that is often used in upward work.

  In addition, since the electromagnet part in this screw driver attracts the screw only when the power is supplied from the power supply part and is excited, the power to the electromagnet part is not used or stored when the screw driver is not used. If the supply is cut off, it becomes easy to remove the screw from the holding state.

  In this screw driver, the electromagnet unit is excited by being supplied with power from the power source unit supplied with external power. Therefore, unlike a screw driver that uses a battery as a driving power source, the electromagnet unit exhibits a strong magnetic force. You can use what you want. Even if an electromagnet portion that exhibits a strong magnetic force is used, there is no problem because the screw can be easily detached from the holding state if the power supply to the electromagnet portion is cut off.

  Furthermore, in this screw driver, whether or not external power is supplied to the screw driver can be clearly determined depending on whether or not the screw is attracted to the electromagnet portion. In this case, it is not forgotten to shut off the supply of the external power source, and the safety is improved.

  In addition, when the electromagnet part in this screw driver is excited by being supplied with power from the power supply part, it can adsorb not only screws but also drilling tools and the like during the work from drilling to screw tightening. Tool change can also be performed quickly.

  That is, the present invention provides a screw driver having a drive unit that is driven by being supplied with an external power supply via a power supply unit, and can hold a screw used for screw tightening without using a connecting screw. Thus, it is possible to provide a screw driver that can be easily handled and can be easily removed from the holding state when the screw driver is not used or stored.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a side view showing a configuration of a screw driver according to the present invention.

  As shown in FIG. 1, the screw driver according to the present invention has an outer casing 1, and a bit that is a screw tightening tool or a drill that is a drilling tool or the like is provided at a distal end portion of the outer casing 1. It has a screw tightening tool mounting portion 3 to which the tool 2 can be detachably mounted. The outer housing 1 is configured in a pistol shape (T-shape or inverted L-shape) and includes a grip portion 4 on the rear side.

  As described later, the outer casing 1 has a power supply unit to which an external power source such as a so-called lamp line is supplied via a power cord 5 and a motor that is driven by driving power supplied from the power source unit. And built-in part. This drive part rotates the tool attachment part 3 for screw fastening.

  The screw driver includes an electromagnet unit 6 that is excited by being supplied with power from the power source unit. The electromagnet portion 6 is installed on one side or both sides of the outer casing 1. The electromagnet portion 6 attracts the screw 7 attached to the tool 2 attached to the screw fastening tool attachment portion 3 when the power is supplied from the power supply portion and is excited. The electromagnet unit 6 can adsorb not only the screw 7 but also a drilling tool or the like when the power is supplied from the power supply unit and excited.

  In the grip part 4, the wiring from the power source part to the motor of the drive part is accommodated. When the switch 8 on the upper side of the grip part 4 is pressed, power is supplied to the drive part, and the tool 2 rotates (correctly). When the switch 8 is released, the rotation of the tool 2 stops.

  The electromagnet unit 6 includes a yoke having a flat tip end surface and an exciting coil (not shown). The yoke of the electromagnet portion 6 is formed of a magnetically permeable material, and is installed with the front end faced outward from one side or both sides of the outer casing 1. The magnetic force exerted when the electromagnet unit 6 is excited is such that the state in which the screws 7 and the like are held by the electromagnet unit 6 can be maintained even when vibration due to work with a screwdriver is applied. The position where the electromagnet portion 6 is installed is not limited to the side surface portion of the upper portion of the outer casing 1 as shown in FIG. 1, but the lower portion of the outer casing 1 or the outer casing. It is good also as a part etc. which connect the lower part of the body 1 and the grip part 4. FIG.

  In addition, in this screw driver, when a drilling tool or the like is attracted to the electromagnet portion 6, tool change during operations from drilling to screw tightening can be performed quickly.

  FIG. 2 is a block diagram showing the configuration of the screw driver according to the present invention.

  As shown in FIG. 2, the screw driver includes a power supply unit 9 to which an external power supply such as a so-called lamp line is supplied via a power cord 5, and a drive unit 10 that is driven by being supplied with a drive power from the power supply unit 9. And have. The power supply unit 9 is supplied with an AC power supply as an external power supply, and rectifies and steps down (or boosts) the AC power supply to supply a DC power supply having a predetermined voltage. As described above, the drive unit 10 rotates the screw fastening tool mounting unit 3.

  The electromagnet unit 6 is excited by being supplied with power from the power source unit 9. The power supplied to the electromagnet unit 6 may be direct current or alternating current. In the configuration shown in FIG. 2, while the external power supply is supplied to the power supply unit 9, power is always supplied to the excitation coil of the electromagnet unit 6 and the electromagnet unit 6 is excited. A switch may be provided between the power supply unit 9 and the electromagnet unit 6 so that the electromagnet unit 6 is excited only when the switch is turned on.

  The drive unit 10 has a motor 15. The motor 15 is, for example, a three-phase brushless DC motor, and U-phase, V-phase, and W-phase drive signals are supplied from the inverter circuit 21. The inverter circuit 21 is composed of six switching transistors, and performs bipolar driving in which a bidirectional driving current is supplied to a Y-connected three-phase coil of the motor 15 to drive the motor 15. Examples of the bipolar driving method include a 120 ° energization rectangular wave driving method. The inverter circuit 21 is supplied with a direct current through the current smoothing capacitor 20 from the power supply unit 9 which is a direct-current power supply.

  The motor 15 is provided with three Hall elements H1, H2, and H3 (hereinafter collectively referred to as H) that are rotation detection elements, corresponding to changes in magnetic poles for each phase of the rotor having a built-in permanent magnet. The rotation signals S1, S2, and S3 (hereinafter referred to as S when collectively referred to) are output. The detection signals S output from the three Hall elements H are input to the three-phase distribution circuit 22. The three-phase distribution circuit 22 is connected to a PWM generation circuit 24 that generates a PWM (pulse width modulation) signal and a rotation direction switching circuit 26.

  A speed command signal corresponding to a predetermined reference rotational speed of the motor 15 is output to the PWM generation circuit 24 by the addition / subtraction of the switch 8. A rotation direction signal for setting the rotation direction is output from the rotation direction command switch 23 to the rotation direction switching circuit 26. The switch 8 and the rotation direction command switch 23 are realized by operation switches such as a trigger type switch, and a predetermined rotation speed and rotation direction are set by an operator's prior setting.

  The PWM generation circuit 24 outputs a PWM waveform corresponding to the rotational speed of the motor 15, that is, the duty of the drive signal, and the rotation direction switching circuit 26 outputs a three-phase drive signal corresponding to a predetermined rotation direction of the motor 15. A signal corresponding to the phase difference between the phases is output. In addition, an overcurrent / thermal protection circuit 29 including a temperature detection element such as a thermistor is connected to the power supply line 30 between the power supply unit 9 and the inverter circuit 21 as an example. A temperature signal corresponding to the temperature near the control circuit 18 detected by 29 is input to the three-phase distribution circuit 22.

  A signal output from the three-phase distribution circuit 22 is input to the gate drive circuit 28 via the lock protection circuit 27. The gate drive circuit 28 performs on / off control of the switching transistors constituting the inverter circuit 21. The lock protection circuit 27 is detected by the three-phase distribution circuit 22 that the rotation of the motor 15 is not detected by the rotation signal S from the three Hall elements H even though the drive signal is output to the motor 15. Then, the signal from the three-phase distribution circuit 22 to the gate drive circuit 28 is forcibly cut off by a lock signal output separately from the three-phase distribution circuit 22.

  The three-phase distribution circuit 22 to which the temperature signal output from the overcurrent / thermal protection circuit 29 is input forcibly narrows the pulse width of the PWM waveform when the detected temperature exceeds the specified set temperature. The output is reduced to prevent further heat generation of the motor 15.

  In the screw driver according to the present invention configured as described above, when the electromagnet portion 6 is energized by being supplied with power from the power source portion 9, the screw 7 used for screw tightening is attracted and held. The screw can be taken out and removed by moving the arm a little without using the connecting screw, and it is easy to handle the screw by removing the trouble of putting it in and out of the mouth and the mouth, and tightening and removing the screw. Work time can be shortened.

  In the screw driver according to the present invention, the screw adsorbed by the electromagnets installed on one side or both sides of the outer casing of the screw driver is carried to the work location while keeping the work location in view. On the contrary, the screw removed from the work location can be easily attracted to the electromagnet, so that the line of sight can be hardly moved, and the time for screw tightening and screw removal can be reduced. And when working upwards, it is possible to reduce the physical burden because the neck is hardly moved, and even when working in places with poor scaffolding, safety is improved by shortening the work time. Can do. Therefore, the present invention is particularly suitable when applied to a board screwdriver that is often used in upward work.

  Further, since the electromagnet unit 6 in this screw driver attracts the screw 7 only when the power is supplied from the power source unit 9 and is excited, the electromagnet unit is used when the screw driver is not used or stored. If the power supply to 6 is cut off, it is easy to remove the screw 7 from the holding state.

  And in this screw driver, since the electromagnet part 6 is supplied with power from the power supply part 9 and excited, it is possible to use one that exhibits a strong magnetic force unlike a screw driver that uses a battery as a driving power source. it can. Even if an electromagnet portion 6 that exhibits a strong magnetic force is used, if the power supply to the electromagnet portion 6 is cut off, the screw 7 can be easily detached from the holding state, so that no problem occurs.

  Furthermore, in this screw driver, whether or not the external power supply is supplied to the screw driver can be clearly determined depending on whether or not the screw 7 is attracted to the electromagnet portion 6, and when the screw driver is not used or stored. The safety is improved without forgetting to cut off the external power supply.

It is a side view which shows the structure of the screw driver which concerns on this invention. It is a block diagram which shows the structure of the said screw driver.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer housing 2 Screw tightening tool 3 Screw tightening tool mounting part 6 Electromagnet part 7 Screw 9 Power supply part 10 Drive part

Claims (1)

A power supply unit supplied with external power;
A drive unit that is driven by being supplied with drive power from the power supply unit;
A screw fastening tool mounting portion that is rotated by the drive portion;
An electromagnet unit that is excited by being supplied with power from the power source unit,
The electromagnet portion is installed on one side or both sides of an outer casing that houses the drive unit, and when the power is supplied from the power supply unit and excited, the screw fastening tool mounting unit A screwdriver characterized by adsorbing a screw to be attached to a screw tightening tool attached to a screwdriver.

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