JP2013086228A - Electric power tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric power tool having a replaceable motor unit with a mechanism portion, and available as various tools.SOLUTION: The electric power tool includes: a motor housing 31 which houses a motor and a power transmission portion; and a grip portion housing 2 which houses a battery 3, a trigger switch 7, a forward-reverse switch 8, and a grip portion formed therein, the motor housing 31 and the grip portion housing 2 being independent of each other; and a motor unit 30 and a grip unit 1 which are detachable. The electric power tool further includes: a control bar 14 which moves along with the forward-reverse switch 8; and a safety mechanism which inhibits detachment of the motor unit 30 and grip unit 1 when the forward-reverse switch 8 is in a forward rotation position or reverse rotation position. The motor unit and grip unit can be detached only when the forward-reverse switch 8 is in a lock position.

Description

  The present invention relates to an electric tool that drives a motor using a secondary battery as a power source and applies a rotational force, rotational impact force, reciprocating force, vibration, or the like to a tip tool, and in particular, a common battery pack. The present invention relates to an electric tool that can be used as various tools using the.

  In recent years, cordless type electric tools using battery packs have been widely used. Since the output voltage of one lithium ion battery widely used in a cordless type electric tool is 3.6 V, the output voltage of the battery pack is often a multiple thereof. Therefore, manufacturers of electric tools are preparing battery packs of 7.2V, 10.8V, 14.4V, 18V, 25.2V, 36V, etc., and aiming to expand the lineup of electric tools that can be adapted to various work. Yes. As an example of such an electric tool, there is a technique disclosed in Patent Document 1. Here, a conventional power tool will be described with reference to FIG. FIG. 11 is a longitudinal sectional view showing the entire configuration of a conventional electric tool (impact driver). The electric tool 101 uses a rechargeable battery pack 103 as a power source, and uses a motor 104 as a drive source to drive a power transmission mechanism (a reduction mechanism 120 using a planetary gear, a striking mechanism 130 including a hammer 132 and an anvil 133), By applying a rotational force and a striking force to the anvil 133 that is integrated with the output shaft 134, a rotational striking force is applied to a tip tool (not shown) such as a driver bit.

  The motor 104 is a DC motor with a brush, and is accommodated in a cylindrical body portion 102a of a housing 102 having a T shape in a side view. A trigger switch 106 is provided at an upper portion of the grip portion 102b extending integrally at a substantially right angle from the body portion 102a of the housing 102. The trigger switch 106 is energized by a spring (not shown) and protrudes from the grip portion 102b. An operation unit 107 is provided. A protective circuit board 105 is accommodated in the lower part of the grip part 102b. A battery pack 103 is attached to the lower portion of the grip portion 102b.

  The striking mechanism 130 includes a spindle 131 and a hammer 132. When the trigger operation unit 107 of the trigger switch 106 is pulled and the motor 104 is started, the rotation of the motor 104 is decelerated by the speed reduction mechanism 120 using a planetary gear. The rotation is transmitted to the spindle 131, and the spindle 131 is rotated at a predetermined speed. Here, the spindle 131 and the hammer 132 are connected by a cam mechanism, and this cam mechanism has a V-shaped spindle cam groove formed on the outer peripheral surface of the spindle 131 and a hammer cam groove formed on the inner peripheral surface of the hammer 132. The ball is engaged with these cam grooves. The hammer 132 is always urged forward by a spring, and when stationary, the hammer 132 is in a position spaced from the end face of the anvil (output shaft 134) by the engagement between the ball and the cam groove. And the convex part which is not shown in figure is formed symmetrically at two places on the rotation plane where the hammer 132 and the anvil face each other. When the spindle 131 is driven to rotate, the rotation is transmitted to the hammer 132 via the cam mechanism, and the hammer 132 engages with the convex portion of the anvil before the hammer 132 is rotated halfway to rotate the anvil. However, when relative rotation occurs between the spindle 131 and the hammer 132 by the engagement reaction force at that time, the hammer 132 is retracted toward the motor 104 while compressing the spring along the spindle cam groove of the cam mechanism. start.

  When the protrusion of the hammer 132 moves over the protrusion of the anvil due to the backward movement of the hammer 132 and the engagement between the two is released, the hammer 132 receives the elastic force accumulated in the spring in addition to the rotational force of the spindle 131. While being accelerated rapidly in the rotational direction and forward by the action of energy and the cam mechanism, it is moved forward by the biasing force of the spring, the convex part is re-engaged with the convex part of the anvil, and the output shaft 134 rotates integrally. start. At this time, since a strong rotational impact force is applied to the anvil, the rotational impact force is transmitted to the screw through a tip tool (not shown) attached to the output shaft 134. Thereafter, the same operation is repeated until the trigger operation unit 107 is released.

JP 2004-174670 A

  However, the conventional battery pack 103 (shaded portion in FIG. 11) is a separate part that is detachable from the main body of the electric power tool 101, and a battery pack housing for protecting the battery cells housed therein. (Outer part) 103 a is required, and the housing 102 also requires the outer part 102 c to be mated with the battery pack 103, and the structure tends to be complicated. Further, when the battery pack 103 is mounted in the vicinity of the grip portion 102b of the electric power tool 101, the grip portion is arranged so that part or all of the battery pack 103 is accommodated up to the inside of the grip portion 102b. There was a problem that the diameter D of the finest detail of 102b would become thick.

  For this reason, it can be considered that a battery is built in the grip portion 102b without using the removable battery pack 103 type. With this configuration, the finest diameter D of the grip portion 102b can be further reduced. However, in such a configuration, the problem is how to charge the battery.

  The present invention has been made in the process of solving the above-described problems, and the object thereof is to make it possible to divide and replace a grip unit including a battery and a trigger switch and a motor unit including a mechanism unit as various tools. It is an object of the present invention to provide an electric tool that can be used and can be formed thin.

  Another object of the present invention is to provide an electric tool that can be used safely by being configured so that the motor does not rotate unexpectedly when the motor unit is attached to or removed from the grip unit.

  Still another object of the present invention is to provide an electric tool that can effectively prevent erroneous attachment of grip units having different voltages to a motor unit.

  The characteristics of representative ones of the inventions disclosed in the present application will be described as follows.

  According to one aspect of the present invention, an electric tool includes a motor, a power transmission unit that transmits the driving force of the motor to drive the tip tool, a motor housing that houses the motor and the power transmission unit, and power to the motor. A battery to be supplied; a switch for adjusting power supply from the battery to the motor; an off switch for disabling the operation of the switch; and a grip part housing for accommodating the battery, the switch, and the off switch and having a grip part formed therein . The electric tool has a motor housing and a grip portion housing that are detachable, and has a safety mechanism that prohibits removal of the motor housing and the grip portion housing when the off switch enables the operation of the switch. The off switch has a lock function that mechanically disables the operation of the switch that adjusts the power supply to the motor, and is, for example, a forward / reverse selector switch that sets the rotation direction of the motor. An attachment base is provided in the upper part of the grip part housing, and an attachment part fixed to the attachment base is formed in the lower part of the motor housing. A plurality of terminals are provided on the attachment portion, a plurality of connectors are provided on the attachment base, and the terminals are connected to the connectors when the attachment portion is attached to the attachment base.

  According to another aspect of the present invention, the safety mechanism includes a control rod provided so as to extend from the mounting base and moving in conjunction with the off switch, and a latch groove provided in the mounting portion and accommodating the control rod. When the mounting part is mounted on the mounting base, the control rod is accommodated in the latch groove, and the operation direction of the mounting part is removed when the control rod contacts the edge of the latch groove unless the switch operation is disabled by the off switch. The latch groove was configured so that it could not be moved. The off switch has, for example, three set positions: a forward rotation position where the motor is rotated in the forward direction, a reverse rotation position where the motor is rotated in the reverse direction, and a lock position where the motor is not rotated. The latch groove is a recess having a substantially H-shaped outer edge when viewed from the bottom, and the control rod is moved to a part of the outer edge of the recess when the mounting part is moved in the forward or reverse rotation position. The stopper part which prevents the movement to the removal direction of was provided. When mounting the mounting part on the mounting base with the off switch in the forward or reverse rotation position, the control rod is moved by moving the mounting part relative to the mounting base to lock the off switch in the locked position. A guide portion to be set in the latch groove was provided.

  According to still another feature of the present invention, the mounting base is provided with a latching portion for holding the mounting portion, the keyway that fits the latching portion is formed in the mounting portion, and the mounting portion is attached. When attached to the base, the latching part fits into the keyway. The shape and size of the latching part is determined according to the rated voltage of the battery, and the shape and size of the keyway is determined according to the rated voltage of the motor, and the grip part has a battery voltage that exceeds the rated voltage of the motor. The housing is configured so that it cannot be attached to a motor housing having a motor. The battery is a 14500 size lithium ion battery, and the battery is charged by removing the motor housing and connecting an external charger to the connector on the mounting base.

  According to the invention of claim 1, since the motor housing and the grip part housing are formed so as to be detachable, the grip part can be used as a battery pack, and various tools can be obtained by exchanging the motor housing including the mechanism part. The motor housing can be supplied at low cost. In addition, a safety mechanism that prohibits removal of the motor housing and grip when the off switch does not invalidate the operation of the switch is provided, so it can be removed only when the motor is stopped. Separation can be prevented.

  According to the invention of claim 2, since the off switch mechanically disables the operation of the switch, the motor housing and the grip portion housing easily prevent rotation of the motor during attachment / detachment by simple operation of the off switch. be able to.

  According to the third aspect of the present invention, since the off switch is a forward / reverse selector switch, the two switching operations of the mode for preventing the rotation of the motor and the mode for setting the rotation direction of the motor can be realized by one switch. Moreover, it is not necessary to provide a dedicated off switch separately, and an existing forward / reverse selector switch can be used.

  According to the invention of claim 4, the mounting portion is provided with a plurality of terminals, the mounting base is provided with a plurality of connectors, and the terminal is connected to the connector when the mounting portion is mounted on the mounting base. Therefore, the battery connection operation can be completed simply by attaching the motor housing to the grip portion housing.

  According to the fifth aspect of the present invention, the safety mechanism includes a control rod provided so as to extend from the mounting base and moving in conjunction with the off switch, and a latch groove provided in the mounting portion and accommodating the control rod. The off switch can be used as an operation lever for operating the latch portion, and it is not necessary to provide a new operation lever for the latch portion, thereby suppressing an increase in the number of parts.

  According to the sixth aspect of the present invention, the two functions of switching the rotation direction of the motor and preventing the rotation of the motor can be realized by one switch mechanism.

  According to the seventh aspect of the present invention, the safety mechanism is a stopper portion that prevents the off switch from moving in the forward rotation or reverse rotation position at a part of the outer edge of the latch groove of the recess having the substantially H-shaped outer edge. A safety mechanism can be realized by simply changing the housing shape.

  According to the invention of claim 8, even if the off switch is mounted in the forward rotation or reverse rotation position, the off switch is automatically returned to the locked position by the guide when the mounting is completed. It is possible to prevent malfunctions that occur.

  According to the ninth aspect of the present invention, since the latching portion formed on the mounting base and the keyway formed on the mounting portion are fitted when the mounting portion is mounted on the mounting base, the motor housing and The grip part housing can be securely fixed.

  According to the invention of claim 10, the latching portion and the key groove are changed in shape and size in accordance with the rated voltage of the battery or the motor, and these have a voltage identification function. It is possible to prevent the grip part housing having the above from being erroneously attached to the motor housing. As a result, since a battery having a rated voltage or higher is not attached, the motor can be prevented from being damaged.

  According to the eleventh aspect of the present invention, the battery built in the grip portion housing is charged by removing the motor housing and connecting the external charger to the connector of the mounting base, so that only the battery portion is removed. There is no need to provide a battery pack housing or the like, and a small and light grip housing can be realized. Further, if a 14500 size lithium ion battery is used as the battery, further miniaturization can be realized.

  The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of the electric tool which concerns on the Example of this invention, the motor unit 30 shows a side view, and the grip unit 1 shows with sectional drawing. FIG. 2 is a bottom view of the motor unit 30 of FIG. 1 and a partial cross-sectional view of the vicinity of the mounting base 10 of the grip unit 1. FIG. 2 is a top view of the grip unit 1 of FIG. 1 and shows a shape of a mounting base 10. It is sectional drawing which shows the relationship between the size of the latching | locking part 13, the keyway 43, and a battery voltage (cross section of CC part of FIG. 3). It is a figure which shows the shape of the latch groove | channel of FIG. It is sectional drawing of the AA part of FIG. It is a block diagram which shows the circuit structure of the electric tool which concerns on the Example of this invention. It is a side view which shows the motor unit 50 which concerns on the 2nd Example of this invention. It is a side view which shows the motor unit 70 which concerns on the 3rd Example of this invention. It is a fragmentary sectional view of the grip unit 91 in the 4th example of the present invention. It is a longitudinal cross-sectional view which shows the whole structure of the conventional electric tool (impact driver).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of the present specification, the up / down / left / right and front / rear directions will be described as directions shown in the drawing. FIG. 1 is a diagram showing an overall configuration of an electric power tool according to an embodiment of the present invention, in which a motor unit 30 is shown in a side view and a grip unit 1 is shown in a sectional view.

  In the present embodiment, the entire tool is configured to be vertically divided on the upper side of the grip portion (also referred to as a handle portion, which is gripped by the operator) of the electric tool. The electric tool includes the motor unit 30 and the grip unit 1. Consists of Although FIG. 1 shows a state in which the motor unit 30 and the grip unit 1 are not attached, the motor unit 30 is moved downward and slid rearward from the illustrated state as indicated by an arrow, so that the motor unit 30 Can be attached to the grip unit 1. A battery 3 is accommodated inside the housing 2 of the grip unit 1. In this embodiment, the removable battery pack 103 as shown in FIG. 11 is not provided in the grip portion, but the battery is built-in. However, from another point of view, the entire grip unit 1 functions as a battery pack, and can be regarded as a form in which the trigger switch 6 and the trigger operation unit 7 are accommodated in the battery pack.

  The grip unit 1 has substantially the same shape as the lower portion of the body portion 102a of the electric power tool 101 shown in FIG. However, since the removable battery pack is not used, the housing 103a (see FIG. 11) of the battery pack 103 can be eliminated, and the battery 3 can be directly mounted in the housing 2 of the grip portion. Therefore, it is not necessary to provide the battery pack housing and the inner wall portion (outer portion 102c in FIG. 11) of the grip portion for housing the battery pack. The battery 3 is a lithium ion battery of 18650 size or 14500 size, for example, and has one cell with a rated output voltage of 3.6 V arranged in the vertical direction (vertical arrangement) and two in the front-rear direction (horizontal arrangement). As shown in the figure, they are arranged in a substantially L shape in a side view. A protection circuit board 5 is arranged in the upper space of the horizontally arranged battery 3. A lead wire 9 connects the battery 3 to the protection circuit board 5 and the protection circuit board 5 to the trigger switch 6. The protection circuit board 5 includes an electronic circuit for monitoring the discharge status of the battery 3 that supplies power, monitoring the abnormal temperature, shutting off the power supply for preventing overdischarge, and other battery protection control, motor control An electronic circuit for carrying out is mounted.

  A motor (not shown) that rotates by electric power supplied from the battery 3 and a power transmission mechanism that transmits the rotational force of the motor to the tip tool are housed on the motor unit 30 side. The motor unit 30 has a cylindrical housing (motor housing) 31, and a mounting portion 32 formed in a planar shape is formed on the lower side of the housing 31 and in a portion in contact with the grip unit 1. The housing 31 can be manufactured by integral molding of a synthetic resin such as plastic, for example, and may be configured to be divided into two parts on the left and right. Below the attachment portion 32, a plurality of terminals 42 are provided for transmitting the power of the battery 3 to the motor when the motor unit 30 is attached to the grip unit 1.

  A trigger switch 6 is provided near the upper end of the grip unit 1 and above the battery 3. The trigger operation portion 7 of the trigger switch 6 protrudes forward from the housing 2 in a state where it is biased by a spring force. The trigger switch 6 is a variable resistance switch. When an operator pushes the trigger operation unit 7 backward, an amount of power proportional to the trigger push-in amount (operation amount) is transmitted to the motor unit 30 side via the connector 12. The In this embodiment, five connectors 12 are provided, and these are fixed to a connector board 16 arranged in parallel with the mounting base 10.

  On the upper side of the trigger operation unit 7, a forward / reverse selector switch 8 is provided for preventing the rotation of a motor (not shown) included in the motor unit 30 by disabling the operation of the trigger operation unit 7. The forward / reverse selector switch 8 enables the operation of the trigger operation unit 7 and changes the rotation direction of the motor to the forward rotation direction or the reverse rotation direction. The operator designates the rotation direction of the motor as the forward rotation direction or the reverse rotation direction by setting the forward / reverse selector switch 8 to the forward rotation position (screw tightening direction) and the reverse rotation position (screw loosening direction). Can do. The movement direction of the forward / reverse selector switch 8 is the left-right direction, and a lock position (neutral or neutral position) for fixing the trigger operation unit 7 so as not to be pulled is provided between the left and right positions. A control rod 14 is fixed to the operation lever of the forward / reverse selector switch 8 so as to extend in the vertical direction, and the control rod 14 moves in conjunction with the left / right movement of the operation lever of the forward / reverse selector switch 8.

  Near the center of the grip unit 1, a latching portion 13 is provided so that the motor unit 30 and the grip unit 1 are stably held, and a key groove 43 that engages with the latching portion 13 is provided on the motor unit 30 side. Is provided. The key groove 43 fulfills a voltage identification function, and the shape and size of the key groove 43 are determined in accordance with the rated voltage of the motor. The motor unit 30 and the grip unit 1 are connected to each other by sliding the motor unit 30 with respect to the grip unit 1 from the front to the rear in accordance with the key groove 43 disposed in the mounting portion 32. At this time, the terminal 42 extending downward from the motor unit 30 is connected to the connector 12.

  The motor unit 30 houses a motor (not shown) in a housing 31 and applies a rotational force to the output shaft 34 by a power transmission unit (not shown) that transmits the driving force of the motor. In this embodiment, the motor 104 may be a direct current motor including a brush mechanism. In this case, the rotational speed of the motor can be easily adjusted from the grip unit side by adjusting the DC voltage supplied to the brush mechanism.

  A sleeve 35 for detachably holding a tip tool (not shown) is provided on the tip side of the output shaft 34. The tip tool can be mounted on or removed from a mounting hole (not shown) provided in the output shaft while the sleeve 35 is moved forward with respect to the housing 31. The tip tool is fixed by releasing the sleeve 35 moved forward. The power transmission unit (not shown) includes a known speed reduction mechanism such as a planetary gear system for reducing the rotational speed of the motor, and a clutch mechanism for blocking output transmission of the speed reduction mechanism. A dial (clutch dial) 33 for mode switching and torque adjustment is connected to the clutch mechanism, and the dial 33 is configured so that an operator can set a driver mode or a drill mode.

  When the dial 33 selects the driver mode, the rotational torque transmitted from the output shaft of the speed reduction mechanism unit to the output shaft 34 is loaded by rotating the torque adjustment dial 33 to a predetermined rotational angle in a plurality of stages. Can be adjusted to a desired tightening torque. The dial 33 can be set, for example, in 22 stages of torque. When setting the dial 33 to the drill mode, the dial 33 is rotated to the maximum rotation angle so that the clutch mechanism does not operate.

  FIG. 2 is a bottom view of the motor unit 30 of FIG. 1 and a partial cross-sectional view (vertical cross-sectional view) near the mounting base 10 of the grip unit 1, including a terminal 42, a connector 12, a key groove 43, and a latching portion 13. The connection relationship between the latch groove 44 and the control rod 14 is shown. The latch groove 44 and the control rod 14 constitute a latch portion 45, which functions as a safety mechanism that prevents the motor unit 30 and the grip unit 1 from being removed in an operating state or an operation ready state. A rectangular attachment portion 32 that is elongated in the front-rear direction is formed in the lower portion of the housing 31 of the motor unit 30. The attachment portion 32 is arranged in a direction perpendicular to the dividing surface of the housing 31 that is divided from the center line to the left and right, and is closely fixed to the attachment base 10 of the grip unit 1. The mounting portion 32 and the mounting base 10 of the present embodiment are planar with each other and are configured to be held by the latching portion 13 and the key groove 43. However, in order to increase rigidity, the mounting portion 32 and the mounting base The base 10 may be configured to be provided with a groove portion extending in the front-rear direction and a rail portion hooked on the groove portion to enhance the mounting rigidity.

  Three terminals 42 a to 42 c are provided behind the attachment portion 32 so as to protrude from the attachment portion 32. The terminal 42a is a plus terminal, and the terminal 42b is an LD terminal (abnormal signal terminal) that receives overdischarge and overcurrent signals from the protection means (IC) mounted on the protection circuit board 5. The terminal 42 c is a minus terminal connected to the battery 3. The mounting base 10 side (grip unit 1 side) has a connector 12d (described later) which is a T terminal (temperature signal terminal) and a connector 12e (described later) which outputs a battery temperature signal to the charger side during charging. However, since these are not used when the motor unit 30 is operated, terminals corresponding to the connectors 12d and 12e are not provided. However, it may be provided as a dummy terminal.

  A keyway 43 is formed near the center of the mounting portion 32. The key groove 43 is a protrusion protruding upward from the mounting base 10 as a key shape or a fixed claw, and the latch unit 13 is pushed into the key groove 43 to move the motor unit 30 relative to the grip unit 1 in the front-rear direction. By doing so, the protruding portion of the latching portion 13 can be brought into contact with the inner wall surface of the mounting portion 32 in contact with the key groove 43. The motor unit 30 is fixed to the grip unit 1 by this contact. The width W in the left-right direction and the position in the left-right direction of the keyway 43 are determined according to the rated voltage of the motor. A substantially H-shaped latch groove 44 is formed on the front side of the key groove 43 as viewed from below (as shown in FIG. 2).

  FIG. 3 is a top view of the grip unit 1 of FIG. 1 and shows the shape of the mounting base 10. The mounting base 10 is the upper wall surface of the housing 2 of the grip unit 1 and is formed so as to straddle the joint surface between the right housing 2-1 and the left housing 2-2 of the housing 2 divided into left and right. Is a rectangular plane. Openings 11a and 11b are provided on the rear side of the mounting base 10, and connectors 12a to 12c are provided on the inner side of the opening 11a. The connector 12 a is a plus terminal connected to the battery 3, and the connector 12 c is a minus terminal connected to the battery 3. The connector 12b is an LD terminal (abnormal signal terminal), and is a terminal that outputs an overdischarge and overcurrent signal from a protection means (IC) mounted on the protection circuit board 5. Connectors 12d and 12e are provided inside the opening 11b. The connector 12d is a T terminal (temperature signal terminal), and is a terminal that outputs a battery temperature signal to the charger side during charging. The connector 12e is an LS terminal (identification terminal) that identifies the type (voltage, etc.) of the battery 3 accommodated in the grip unit 1 from the charger when the grip unit 1 is connected to a charger (not shown). is there. The connectors 12d and 12e are used only during charging, but are not used during discharging, that is, when connected to the motor unit 30. The number and types of connectors to be provided are not limited to this, and may be further provided as necessary. For example, a connector for a plus terminal and a minus terminal for lighting the LED on the motor unit 30 side may be further provided.

  A hooking portion 13 is formed near the center of the mounting base 10. The width W of the latching portion 13 and its mounting position are determined according to the rated voltage of the battery 3. A control rod 14 accommodated in the latch groove 44 is provided in front of the latching portion 13. A latch portion 45 is constituted by the latch groove 44 and the control rod 14. The control rod 14 is fixed to the operation lever of the forward / reverse selector switch 8, and the opening 15 formed in the mounting base 10 by setting the forward / reverse selector switch 8 to the forward rotation position and the reverse rotation position. Move left and right inside. Note that the position of the control rod 14 in FIG. 3 indicates a state in which the operating lever of the forward / reverse selector switch 8 is in the locked position (neutral position). The motor unit 30 and the grip unit 1 are attached by aligning the latching portion 13 with the key groove 43 for voltage identification and sliding the motor unit 30 from the front to the rear.

  Next, the relationship between the size of the latching portion 13 and the key groove 43 and the mounting position will be described with reference to FIG. FIG. 4 is a diagram showing the shapes of the housing 2 of the grip part and the housing 31 of the motor unit at the cross-sectional position of the CC part of FIG. Since each can be divided into left and right parts, the right housing will be described with a branch number “−1” and the left housing with a branch number “−2”. Further, there are variations of 36V to 3.6V depending on the rated voltage of the battery 3 or the operating voltage of the motor. In those cases, the reference numerals of the housing 2 and the housing 31 are denoted by symbols a to g. Are described separately.

  The locking portion 13 and the key groove 43 shown in FIGS. 1 to 3 are of the 10.8 V specification as shown in FIG. As shown in FIG. 4 (5), the left end of the right housing 31e-1 and the right end of the left housing 31e-2 form a key groove 43e, and its width is e. Similarly, the left end protrusion of the right housing 2e-1 and the right end protrusion of the left housing 2e-2 are joined to form the latching portion 13e. Here, as can be understood by referring to FIGS. 4 (1) to (7), the width W of the latching portion 13 and the key groove 43 is set so that the width varies from a to g depending on the voltage. At this time, the width increases as the voltage changes from a low voltage to a high voltage, and the left and right positions thereof are set to a position including the position of the latching portion 13 having a low voltage. For example, the hook portion 13g for 3.6V is arranged so as to be included in the width f of the key groove 43f for 7.2V. Similarly, for example, the latching portion 13c for 18V is determined so as to be included in the range of the keyway 43b for 25.2V. By arranging in this way, the grip unit 1 having the low-voltage battery 3 can be attached to the motor unit 30 having a high operating voltage. However, the reverse relationship does not hold, and the grip unit 1 having the high voltage battery 3 cannot be mounted on the motor unit 30 having a low operating voltage, so that a high voltage higher than the operating voltage is erroneously supplied to the motor. It is possible to prevent the motor from being damaged. Moreover, since each keyway 43a-43g is formed on both sides of the joint surface of housings 31a-31g, manufacture by integral molding is easy. Similarly, since the latching | locking parts 13a-13g are formed on both sides of the joint surface of the housings 2a-2g, manufacture by integral molding is easy. As described above, by providing the motor unit 30 and the grip unit 1 with the key groove 43 for identifying the voltage, it is possible to prevent the motor unit 30 having a low rated voltage from being used for the grip unit 1 having a high rated voltage.

  Next, the detailed shape of the latch groove 44 will be described with reference to FIG. The latch groove 44 has two parallel portions of H (the portions along the center lines 48a and 48b, and the lateral grooves 44a and 44c extending in the left-right direction) are in the left-right direction, and are connected portions (center lines) connecting the parallel portions. 48 c is a notch or groove portion arranged so that a longitudinal groove 44 b) extending in the front-rear direction extends in the front-rear direction, and guides or restricts movement of the control rod 14 by its outer peripheral edge. To do. When the motor unit 30 is mounted on the grip unit 1, the control rod 14 is at the position 46 in order to place the forward / reverse selector switch 8 in the locked position, and the control is performed by sliding the motor unit 30 backward with respect to the grip unit 1. The rod 14 moves from position 46 to position 47. When the motor unit 30 is operated to perform an operation using an electric tool, the forward / reverse selector switch 8 is set to the forward rotation direction or the reverse rotation direction, and accordingly, the control rod 14 is linked to the position 47a (forward rotation direction). ) Or position 47b (reverse direction). When the operation with the electric tool is completed and the motor unit 30 is removed from the grip unit 1, the forward / reverse selector switch 8 is normally set to the locked position. Then, the control rod 14 is in the position 47. By sliding the motor unit 30 forward with respect to the grip unit 1 in this state, the control rod 14 moves from the position 47 to the position 46, and in this state, the motor unit 30 can be detached from the grip unit 1. However, if the operator tries to remove the motor unit 30 from the grip unit 1 while the forward / reverse selector switch 8 is in the forward rotation direction or the reverse rotation direction, the control rod 14 is at the position 47a or 47b. The rearward movement is prevented by the protruding portion 44d that protrudes so as to approach the intersection of the center lines 48c and 48b along the outer periphery of the formed control rod 14. Therefore, when the operator removes the motor unit 30 from the grip unit 1, it is necessary to always return the forward / reverse selector switch 8 to the locked position, so that it is possible to reliably prevent the motor from rotating during removal.

  In the present embodiment, since the latch groove 44 is formed in a substantially H shape, the convenience at the time of mounting can be achieved. Normally, when the motor unit 30 is attached to the grip unit 1, the forward / reverse selector switch 8 should be in the locked position. However, when the forward / reverse selector switch 8 is set in the forward rotation direction or the reverse rotation direction for some reason, it cannot be mounted as it is. In this case, it is necessary to perform the mounting operation again after returning the forward / reverse selector switch 8 to the locked position, which is troublesome. Therefore, the forward / reverse selector switch 8 can be mounted in either the forward rotation position (the control rod 14 is at the position 46a) or the reverse rotation position (the control rod 14 is in the position 46b). If the motor unit 30 is moved backward with respect to the grip unit 1 when the control rod 14 is at the position 46a or 46b, the control rod 14 is automatically moved to the center in the left-right direction by the inclined portion 44e. When the mounting operation is completed, the control rod 14 settles at the position 47. As a result, even if the motor unit 30 is attached to the grip unit 1 while the forward / reverse selector switch 8 is set to the forward rotation position or the reverse rotation position, it is possible to reliably prevent a malfunction that the motor suddenly rotates after the attachment is completed.

  6 is a cross-sectional view taken along a line AA in FIG. A mounting portion 32 is formed in a lower part of a motor unit housing (motor housing) 31, and terminals 42 a to 42 c are provided side by side in three rows. From this figure, it can be understood that the cylindrical shape of the housing 31 and the flat mounting portion 32 that protrudes downward from the cylindrical shape are formed.

  FIG. 7 is a block diagram showing a circuit configuration of the electric power tool according to the embodiment of the present invention. The grip unit 1 includes a battery 3 including three lithium ion battery cells, and is connected to the connectors 12a and 12c via the protective circuit board 5 and the trigger switch 6 and the forward / reverse selector switch 8. . On the other hand, the motor unit 30 is provided with a motor 36, a planetary gear reduction mechanism 37, and a clutch mechanism 38. Electric power is supplied to the motor 36 via the terminals 42a and 42c and the connectors 12a and 12c. A switching element 39 such as an FET is arranged in series in the current path between the battery 3 and the motor 36. When the protection means (IC) mounted on the protection circuit board 5 detects that the battery 3 is overdischarged or the current flowing through the battery 3 (motor 36) is overcurrent, the protection means (IC) detects overdischarge or overcurrent. A signal (abnormal signal) is output and input to the switching element 39 via the terminal 42b serving as the LD terminal and the connector 12b. Then, the switching element 39 is turned off and the current path is interrupted, so that the battery 3 and the motor 36 can be protected. In the configuration of the present embodiment, the battery pack using a 18650 type battery when comparing a 10.8 V tool by eliminating the outer portion of the battery pack and mounting the battery 3 directly in the housing 2 of the grip unit 1. Compared to the diameter D of the conventional example (FIG. 11) using JIS, the grip part diameter D1 (see FIG. 1) could be reduced by about 2 mm. Further, by allowing the entire grip unit 1 to function as a battery pack, it can be used as various tools by exchanging the motor unit 30 including the mechanism portion, and the motor unit portion can be supplied at low cost.

  Next, the shape of the motor unit 50 according to the second embodiment of the present invention will be described with reference to FIG. In FIG. 8, a motor unit 50 includes a motor (not shown), a planetary gear speed reduction mechanism, and a striking mechanism (impact mechanism) arranged coaxially in a housing 51, and provides rotational force and striking force to an output shaft 53 that penetrates the hammer case 52. By giving, the tip tool (not shown) is rotated. A mounting portion 60 is formed in the lower portion of the housing 51, and a terminal 62, a key groove 63, and a latch groove 64 are provided from the rear side. The size and arrangement of the mounting portion 60 may be the same as the terminal 42, the key groove 43, and the latch groove 44 shown in FIG. As described above, the driver drill (FIG. 1) and the impact driver (FIG. 8) can be easily prepared by mounting the motor unit 50 on the grip unit 1 instead of the motor unit 30.

  Next, the shape of the motor unit 70 according to the third embodiment of the present invention will be described with reference to FIG. The motor unit 70 is a saver saw, and a housing 71 includes a motor (not shown) and a power transmission mechanism that converts the rotational motion of the motor into the reciprocating motion of the flange. At the distal end portion of the housing 71, a fixing screw mounting portion 72 for the left and right divided housings at a part of the housing 71 and a blade holder 73 for restricting the lateral movement of the blade as a distal tool (not shown) are provided. The blade holder 73 also has a role of guiding the cutting by the blade by abutting against the counterpart material. A mounting portion 80 is formed at the lower portion of the housing 71, and a terminal 82, a key groove 83, and a latch groove 84 are provided from the rear side. The size and arrangement of the mounting portion 80 may be the same as the terminal 42, key groove 43, and latch groove 44 shown in FIG. As described above, the driver drill (FIG. 1) and the saver saw (FIG. 9) can be easily prepared by replacing the motor unit 50 with the grip unit 1 instead of the motor unit 70. Here, unlike a driver, a saver saw or circular saw in which a motor unit and a grip unit are configured integrally is different from a driver in that the motor always rotates in one direction. It is. Therefore, when the saver saw mounting portion 80 is connected to the grip unit 1 of the present invention, the latch groove 84 is provided so that the motor can be driven when the control rod moves to the position 47a in FIG. What is necessary is just to form. Further, a dedicated grip unit for a saver saw may be prepared, and a simple off switch (a switch for switching whether to allow or lock the trigger switch) may be provided instead of the forward / reverse selector switch.

  Next, the structure of the grip unit 91 according to the fourth embodiment of the present invention will be described with reference to FIG. A rechargeable battery 93 having the same shape as an AA battery (primary battery) was used inside the housing 92 of the grip unit 91. As the battery 93, for example, a 14500 size lithium ion battery (secondary battery) can be used. When the 14500 size battery 93 was used, the diameter D2 of the grip portion could be reduced by about 5 mm compared to the diameter D of the conventional example (see FIG. 11). As can be understood from FIG. 10, when a 14500-size battery 93 is used, there is room in the internal space of the housing 92. Therefore, the lower end of the housing is not made into a large shape of a substantially rectangular parallelepiped, but may be further narrowed, and the entire battery 93 is accommodated in the cylindrical part of the grip part (the part gripped by the operator). You may do it.

  As described above, according to the embodiments of the present invention, it is possible to easily realize various types of electric tools by simply using the grip unit and replacing only the motor unit. In addition, by using the forward / reverse selector switch for the latch mechanism of the grip unit, when the motor unit is removed from the grip unit, the motor unit can be detached only when the motor is stopped and can be safely separated. Furthermore, by providing a key groove for identifying the voltage between the motor unit and the grip unit, it is possible to prevent a motor unit with a low rated voltage from being erroneously attached to a grip unit with a high rated voltage. In addition, in impact drivers where the tip tool mounting part and hammer mechanism part come first, the trigger switch and forward / reverse switch are on the same side as the battery, so only the fragile motor unit part is replaced. Therefore, there is an effect that the cost merit is high.

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various change is possible within the range which does not deviate from the meaning. For example, in the above-described embodiments, the driver unit, the impact driver, and the saver saw unit are described as examples of the motor unit. However, the unit is not limited to this, and may be a unit that constitutes another known electric tool. Further, in the above-described embodiment, the concave portion that is the key groove 43 is formed on the motor unit 30 side, and the convex portion that is the latching portion 13 is formed on the grip unit 1 side, but the grip unit having a high rated voltage is on the motor unit side having a low voltage specification. If they are combined so that they cannot be attached, the positions where the concave portions and the convex portions are provided may be reversed. In addition, the motor unit 30 and the grip unit can be changed by using a known fixing means such as a change in the concavo-convex shape or a guide rail or buckle. 1 may be detachably fixed.

  In the above-described embodiment, the forward / reverse selector switch 8 is provided on the grip unit side, and the concave portion that is a latch groove is formed on the motor unit side and the convex portion that is a control rod is formed on the grip unit side. May be provided on the motor unit side. In this case, a latch groove may be provided on the grip unit side. In this way, a grip unit can be shared between a power tool such as a driver with a forward / reverse switch and a power tool such as a circular saw with an off-lock switch that keeps the trigger switch (trigger operation unit) off. Can be easily achieved. In the case of a forward / reverse selector switch, the operation is the same as in the above-described embodiment. In the case of an off-lock switch, a latch groove may be formed so that the connection between the motor unit and the grip unit can be released only when the switch is in the locked state.

DESCRIPTION OF SYMBOLS 1 Grip unit 2 Housing 2-1 Right side housing 2-2 Left side housing 3 Battery 5 Protection circuit board 6 Trigger switch 7 Trigger operation part 8 Forward / reverse selector switch 9 Lead wire 10 Mounting base 11a, 11b Opening part 12, 12a, 12b , 12c, 12d, 12e Connector 13 Latching part 14 Control rod 15 Opening part 16 Connector board 30 Motor unit 31 Housing 32 Mounting part 33 Dial 34 Output shaft 35 Sleeve 36 Motor 37 Planetary gear reduction mechanism part 38 Clutch mechanism part 39 Switching element 42, 42a, 42b, 42c Terminal 43 Key groove 44 Latch grooves 44a, 44c Lateral groove 44b Front / rear groove 44d Projection (stopper) 44e Inclination (guide)
45 Latch part 50 Motor unit 51 Housing 52 Hammer case 53 Output shaft 60 Mounting part 62 Terminal 63 Key groove 64 Latching groove 70 Motor unit 71 Housing 72 Mounting part 73 Blade holder 80 Mounting part 82 Terminal 83 Key groove 84 Latching groove 91 Grip unit 92 Housing 93 Battery 101 Power tool 102 Housing 102a Body portion 102b Grip portion 102c Outer portion 103 Battery pack 104 Motor 105 Protection circuit board 106 Trigger switch 107 Trigger operation portion 120 Reduction mechanism 130 Impact mechanism 131 Spindle 132 Hammer 133 Anvil 134 Output shaft 135 sleeve

Claims (11)

A motor,
A power transmission unit for transmitting the driving force of the motor to drive the tip tool;
A motor housing that houses the motor and the power transmission unit;
A battery for supplying power to the motor;
A switch for adjusting power supply from the battery to the motor;
An off switch for disabling the operation of the switch;
A grip part housing that accommodates the battery, the switch, and the off switch and has a grip part formed therein,
The motor housing and the grip portion housing are detachably formed,
An electric tool comprising a safety mechanism that prohibits removal of the motor housing and the grip portion housing when the off switch enables the switch.   The power tool according to claim 1, wherein the off switch mechanically disables the operation of the switch.   The electric tool according to claim 2, wherein the off switch is a forward / reverse selector switch that sets a rotation direction of the motor. A mounting base is provided at the top of the grip part housing,
A mounting portion fixed to the mounting base is formed at a lower portion of the motor housing,
The mounting part is provided with a plurality of terminals,
The mounting base is provided with a plurality of connectors,
The electric tool according to any one of claims 1 to 3, wherein the terminal is connected to the connector when the attachment portion is attached to the attachment base. The safety mechanism is configured by a control rod provided so as to extend from the mounting base and moving in conjunction with the off switch, and a latch groove provided in the mounting portion and accommodating the control rod,
When the mounting portion is mounted on the mounting base, the control rod is accommodated in the latch groove,
The latch groove is configured so that the mounting portion cannot be moved in the detaching direction when the control rod contacts the edge of the latch groove unless the operation of the switch is invalidated by the off switch. The power tool according to claim 4.   The off switch has three set positions: a forward rotation position where the motor is rotated in the forward direction, a reverse rotation position where the motor is rotated in the reverse direction, and a lock position where the motor is not rotated. The power tool according to claim 5. The latch groove is a recess having a substantially H-shaped outer edge when viewed from the bottom,
A stopper portion is provided on a part of the outer edge of the recess to prevent the control rod from moving in the removal direction when the mounting portion is moved while the off switch is in the forward rotation or reverse rotation position. The power tool according to claim 6.   When mounting the mounting portion on the mounting base in a state where the off switch is in a forward rotation or reverse rotation position, the control rod is moved by moving the mounting portion relative to the mounting base. The electric tool according to claim 7, wherein a guide portion for setting the off switch to a locked position is provided in the latch groove.   The mounting base is provided with a latching part for holding the mounting part, a keyway is formed on the mounting part to be fitted with the latching part, and the mounting part is attached to the mounting base. The electric tool according to any one of claims 1 to 8, wherein the hooking portion is fitted with the keyway. The shape and size of the latching portion are determined according to the rated voltage of the battery,
The shape and size of the keyway are determined according to the rated voltage of the motor,
The electric tool according to claim 9, wherein the grip part housing having a battery voltage equal to or higher than a rating of the motor is configured not to be mounted on the motor housing having the motor.   11. The battery according to claim 1, wherein the battery is a 14500-size lithium ion battery, and the battery is charged by removing the motor housing and connecting an external charger to a connector of the mounting base. The power tool according to any one of the above.

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