JP2013188854A - Power tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power tool guaranteeing reliability of fastening work by performing the control so that it is actuated only when operated by using both hands.SOLUTION: In a power tool comprising a housing 11 housing a drive shaft, a handle 15 projecting at a rear end of the housing, a tubular part projecting in front of the handle and housing a prime mover capable of transmitting power to the drive shaft, and a casing 17 connecting a distal end of the handle and a distal end of the tubular part and housing a control part 40 controlling operation of the prime mover, the power tool comprises a first switch 20 provided at the handle and electrically connected to the control part and a second switch 30 provided at a front lower part of the tubular part or a front end of the casing and electrically connected to the control part. The control part is configured to actuate the prime mover only when both of the first switch and the second switch are operated.

Description

  The present invention relates to a power tool such as a tightening machine that includes two switches and is operable only when both of these switches are operated. More specifically, the present invention relates to a tightening machine including a reaction force receiver. It relates to power tools such as.

There are known power tools such as a tightening machine used for fastening bolts and nuts, and so-called shear bolts having shearing tips.
In these power tools, a handle that is a handle has one switch for turning on / off its operation, and power is transmitted from the motor by operating the switch while grasping the handle.

  During the tightening preparation work using the power tool, the operator may operate if the operator accidentally touches the finger unintentionally.

  In addition, although a so-called reaction force receiver is provided at the tip of the tightening machine (see, for example, Patent Document 1), in particular, in such a tightening machine, the socket is securely attached to a bolt, a nut, or the like. The operator is required to operate the tightening machine with both hands in a state where the reaction force receiver rotating in the direction opposite to the socket is applied to the projection.

JP 2001-113470 A

  However, it may be operated with one hand due to carelessness or the like, which may cause poor tightening of bolts and nuts.

  The objective of this invention is providing the power tool which can ensure the certainty of a fastening operation | work by controlling so that it may operate | move only when it operates using both hands.

In order to solve the above problems, the power tool of the present invention is:
A housing housing the drive shaft;
A handle protruding from the rear end of the housing;
A cylindrical portion that protrudes in front of the handle and contains a prime mover capable of transmitting power to the drive shaft;
A casing in which a control unit that connects the tip of the handle and the tip of the tube part and controls the operation of the prime mover is housed,
In a power tool comprising
A first switch disposed on the handle and electrically connected to the control unit;
A second switch that is disposed at a front lower portion of the cylindrical portion or a front end of the casing and is electrically connected to the control portion;
With
The control unit operates the prime mover when both the first switch and the second switch are operated.

According to the present invention, the prime mover operates only when both the first switch and the second switch are operated. The first switch is provided on the handle, and the second switch is provided on the lower front side of the cylinder part or on the front end of the casing. These switches cannot be operated with one hand, so the first switch with one hand and the other The second switch must be operated by hand.
Therefore, the power tool cannot be operated unless it is operated with both hands, and the bolt or nut is not sufficiently attached to the socket, or the reaction force receiver is not applied to the projection. It is possible to prevent erroneous operation in the state.
As described above, according to the power tool of the present invention, the certainty of the tightening work can be ensured and the safety can be enhanced.

FIG. 1 is a left side view of a tightening machine according to an embodiment of the present invention. FIG. 2 is a right side view of the same. FIG. 3 is a front view of the same. FIG. 4 is a rear view of the same. FIG. 5 is a plan view of the same. FIG. 6 is a bottom view of the same. FIG. 7 is a front view showing the internal structure of the second switch unit provided with the second switch in a non-operating state. 8A is a fragmentary sectional view taken along line 8a-8a in FIG. 7, and FIG. 8B is a fragmentary sectional view taken along line 8b-8b in FIG. FIG. 9 is a front view showing the internal structure of the second switch unit in a state where the second switch on the left side is pressed. FIG. 10 is a front view showing the internal structure of the second switch unit in a state where the second switch on the right side is pressed. 11A is a partial fragmentary sectional view taken along line 11a-11a in FIG. 9 or FIG. 10, and FIG. 11B is a partial fragmentary sectional view taken along line 11b-11b in FIG. 9 or FIG. is there. FIG. 12 is a circuit diagram showing an embodiment of the present invention. FIG. 13 is a circuit diagram showing a different embodiment of the present invention. FIG. 14 is a circuit diagram showing still another embodiment of the present invention.

  Hereinafter, an embodiment in which the present invention is applied to a two-axis type tightening machine (10) for tightening bolts and nuts as power tools will be described. The power tool is not limited to the two-axis type tightening machine (10), and may be, for example, an impact wrench, an impact driver, a vibration / hammer drill, etc. It can be used for any prime mover such as pneumatic, hydraulic, etc.

1 to 6 show a two-shaft type tightening machine (10) to which the present invention is applied.
The tightening machine (10) incorporates a planetary gear mechanism inside a cylindrical housing (11), and is concentric twin shafts composed of an inner shaft and an outer shaft that are rotatable in opposite directions via the planetary gear mechanism. With a drive shaft. As shown in FIG. 3, a socket (12) to which a bolt, a nut, or the like is attached is connected to the tip of the inner shaft, and the shaft of the outer shaft is connected to the tip of the outer shaft as shown in FIGS. A reaction force receiver (13) having an arm (14) extending in a direction perpendicular to the core is connected. The socket (12) and the reaction force receiver (13) can be formed integrally with the inner shaft and the outer shaft, or can be detachably formed.

  On the rear end of the housing (11), that is, on the side opposite to the front end where the socket (12) and the reaction force receiver (13) are connected, a handle (15) gripped by the operator is attached as shown in the figure. The handle (15) is provided with a first switch (20). In the illustrated embodiment, the first switch (20) is a push-type switch disposed near the upper end of the handle (15), and is operated by pressing the index finger with the operator holding the handle (15). A first switch button (21) is attached. The first switch (20) is electrically connected to a control unit (40) described later.

  The housing (11) has a cylindrical portion (16) that houses a prime mover such as a motor connected to the planetary gear mechanism so as to be able to transmit power to the front of the handle (15) and projects in the same direction as the handle (15). Has been.

The lower end of the handle (15) and the cylinder part (16) are connected by a casing (17), and a control part (40) for controlling the prime mover is accommodated in the casing (17). The control unit (40) controls, for example, forward / reverse rotation, output, and tightening torque of the motor.
A wiring (18) that can be connected to a commercial power source is provided at the rear end of the casing (17) to supply power to the motor, the control unit (40), and the like.

  The front end of the casing (17) is provided with a second switch (30) for switching on and off the prime mover in cooperation with the first switch (20).

  As a specific embodiment, the second switch (30) includes a right second switch button (32), a left second switch button (33), a second switch button (32) or (33 ) Can be used as the second switch unit (31) including the sub switch (37) that is switched on and off.

  As a specific embodiment, the second switch unit (31) includes a right second switch button (32) and a left second switch button that are projected in front of the casing (17) so as to be operable from both left and right directions. (33) and a switch mount (31a) covering the outside of the second switch unit (31). As shown in FIGS. 7 and 8, the switch mount (31a) is electrically connected to the control unit (40) and transmits the operation of the second switch (30) to the control unit (40). A switch (37) is deployed.

  As a specific embodiment of the left and right second switch buttons (32) and (33), the second switch buttons (32) and (33) are switched inside the switch mount (31a) as shown in FIGS. It can be set as the structure connected by the rod (34). That is, each end of the switch rod (34) becomes the left and right second switch buttons (32) and (33), respectively.

The switch rod (34) is biased in the axial direction by a biasing means such as a spring (35) so as to maintain a neutral state in an unloaded state.
In FIG. 8 (b), a spring (35) which is an urging means for the switch rod (34) is fitted in a left and right concave groove (18) formed on the front inner surface of the casing (17). The concave groove (18) is formed to a depth such that a part of the periphery of the spring (35) protrudes toward the switch rod (34). Also, the length of the concave groove (18), that is, the distance L between the left and right end faces (18a) (18b) (shown by dotted lines in FIG. 7) is a little when the spring (35) hits both end faces (18a) (18b). 9 and FIG. 9 even when the spring (35) is pushed into the second switch button (32) or (33) and pressed against the pressing surfaces (36a) and (36b) as will be described later. As shown in FIG. 10, it is set so that it is not completely compressed.

In order to apply the urging force of the spring (35) to the switch rod (34), when the switch rod (34) is slid in the axial direction, as shown in FIGS. Further, the pressing surfaces (36a) and (36b) on which the switch rod (34) presses the end surface of the spring (35) are formed so as to protrude outward from the shaft core. The space between the pressing surfaces (36a) and (36b) is the same as or slightly wider than the end surface in the left-right direction of the concave groove (18).
In the illustrated embodiment, the pressing surfaces (36a) and (36b) are formed by forming a part of the switch rod (34) as a thin shaft (34a). A configuration that protrudes from (34) may be adopted.

  The switch rod (34) is attached to the casing (17), the spring (35) is fitted into the concave groove (18), and then the spring cover (35a) (see FIG. 8 (b)) is fitted, whereby the spring (35 ), The peripheral edge protruding from the concave groove (18) hits the thin shaft portion (34a) of the switch rod (34) and the spring cover (35a), and cannot be removed from the concave groove (18).

  As shown in FIG. 9, when the right second switch button (32) is pressed, the switch rod (34) having the above configuration moves the pressing surface (36a) in the right direction and moves the end surface (18b) of the concave groove (18). ), And slides to the right against the biasing force of the spring (35) while compressing the spring (35). As shown in FIG. 10, when the left second switch button (33) is pressed, the pressing surface (36b) moves to the left and the spring (35) is formed between the end surface (18a) of the groove (18). ) And slide to the left.

  When the pressing force on the second switch buttons 32, 33 is released, the switch rod 34 returns to the neutral state as shown in FIG. 7 by the restoring force of the spring 35.

  On the other hand, since the switch rod (34) does not slide even if the operator accidentally presses the left and right second switch buttons (32) and (33) at the same time, erroneous operation can be suppressed.

  The switch rod (34) having the above configuration operates the sub switch (37). The switch rod (34) is formed with a tapered recess (36), which switches on / off a sub switch (37) described below.

  The sub switch (37) includes a swingable switch lever (38) as shown in FIGS. 7 and 8 in the off state and FIGS. 9 to 11 in the on state. The sub switch (37) has a switch lever (38) biased in the protruding direction, and has a built-in switch mechanism that switches on and off by swinging the switch lever (38). The switch mechanism is electrically connected to the control unit (40).

  As shown in FIGS. 7 and 8, the sub-switch (37) is in the recess (36) of the switch rod (34) that maintains the neutral position by the urging force of the spring (35) in the no-load state. The tip of the switch lever (38) is fitted, and the power supply is cut off and turned off.

  From this state, when the operator presses the right second switch button (32) or the left second switch button (33) with a finger, the biasing force of the spring (35) as shown in FIG. 9, FIG. 10, or FIG. Against this, the switch rod (34) slides, the tip of the switch lever (38) comes out of the recess (36) and rides on the thick part of the shaft of the switch rod (34). By this operation, the switch lever (38) swings upward, and the sub switch (37), that is, the second switch (30) is energized and turned on.

  When the operator releases the pressing force on the second switch button (32) or (33), the switch rod (34) returns to the neutral position by the restoring force of the spring (35), as shown in FIGS. Then, the switch lever (38) swings in the opposite direction to the above and fits into the recess (36) again, and the sub switch (37) is turned off.

  By pressing the second switch button (32) or (33) as described above, the second switch (30) can be switched on and off.

12 to 14 show examples of circuit diagrams of the tightening machine (10) including the first switch (20) and the second switch (30).
In FIG. 12, a first switch (20) and a second switch (30) are connected in series with a motor (41) and an AC power supply (42). As can be seen from FIG. 12, the motor (41) is not energized unless both the first switch (20) and the second switch (30) are turned on. Note that the circuit of FIG. 12 is the most simplified circuit, and omits the control unit (40) for controlling the rotation and output of the motor (41).

  In FIG. 13, a first switch (20) and a second switch (30) connected in series are connected to a control unit (40), and a motor (41) and an AC power source (42) are also connected to the control unit ( 40) is connected. In the circuit of FIG. 13, the controller (40) detects that both the first switch (20) and the second switch (30) are turned on, and the motor (41) is energized. Yes.

  In FIG. 14, the first switch (20) and the second switch (30) are separately connected to the control unit (40). Similarly, the motor (41) and the AC power source (42) are also connected to the control unit (40). Connected to. In the circuit of FIG. 14, the controller (40) detects whether the first switch (20) and the second switch (30) are on or off, and the controller (40) detects both switches (20) (30). When the on-state is detected, the motor (41) is energized.

  In any of the circuits shown in FIGS. 12 to 14, the motor (41) is energized only when both the first switch (20) and the second switch (30) are turned on. When one or both are off, the motor (41) is not energized.

  In the tightening machine (10) configured as described above, the operator holds the handle (15) with the right or left hand, attaches the other hand to the vicinity of the front end of the casing (17) or grips the vicinity of the front end of the casing (17), Attach the socket (12) to a bolt, nut, etc., and apply the reaction force receiver (13) to the projection.

  From this state, press the first switch (20) with the index finger of the hand holding the handle (15), and press one of the left and right second switch buttons (32) (33) with the opposite finger. The first switch (20) and the second switch (30) are turned on, and the motor (41) is energized. As a result, the socket (12) rotates in a predetermined direction, and the reaction force receiver (13) rotates in the opposite direction to the socket (12), and the reaction force receiver (13) hits the projection and reacts by tightening. Bolts and nuts are tightened while receiving force.

  Further, when the pressing force applied to the first switch (20) or the second switch (30) is released, the energization is cut off and the rotation of the motor (41) is stopped.

  As described above, the tightening machine (10) of the present invention is safe because the motor (41) cannot be operated unless both the first switch (20) and the second switch (30) are operated. Excellent.

  In addition, since the second switch (30) can be operated from either the left or right side, the second switch (30) is attached to or gripped by the hand (generally the dominant hand) holding the handle (15) and the casing (17). Regardless of the left and right hand to operate 30).

  Further, since the second switch (30) is provided at a position close to the control unit (40), the electrical wiring to the control unit (40) can be shortened, and the electrical wiring is exposed to the outside. Therefore, there is no need to separately install parts for protecting the electrical wiring, and insulation is ensured.

  Further, the first switch (20) and the second switch (30) are held in a state in which the handle (15) is held with one hand and the other hand is attached to or held by the casing (17) and the clamping machine (10) is held. ) Can be performed stably even when a heavy-duty tightening machine is used or when the tightening machine is used upward.

  In addition, the socket (12) can be fitted into the bolt or nut while holding the tightening machine (10) with both hands, so these operations can be performed reliably, and thereafter, the switch (20) ( 30) can be performed and the workability is also excellent.

  In the above embodiment, the second switch (30) is operated by sliding one switch rod (34), but the configuration of the second switch (30) is not limited to this. For example, a switch such as a push-down type can be provided on the left and right sides of the casing (17), and these can be connected in parallel to form the second switch (30). Of course, the configuration of the first switch 20 is not limited to these.

  In the above embodiment, the power tool is a two-shaft type tightening machine (10) having a reaction force receiver (13), but it is obvious that the present invention is not limited to this.

  Furthermore, in the above description, the second switch (30) is provided at the front end of the casing (17). However, the second switch (30) can be provided at the lower part on the front side of the cylindrical portion (16). Depending on the form of the tool, the control unit may be arranged in another part and the casing (17) may be omitted.

  The present invention is useful as a power tool such as a tightening machine that cannot be operated unless both switches are operated.

(10) Clamping machine (power tool)
(15) Handle
(16) Tube section
(17) Casing
(20) First switch
(30) Second switch
(32) Right second switch button
(33) Second left switch button
(34) Switch rod

Claims (2)

A housing housing the drive shaft;
A handle protruding from the rear end of the housing;
A cylindrical portion that protrudes in front of the handle and contains a prime mover capable of transmitting power to the drive shaft;
A casing in which a control unit that connects the tip of the handle and the tip of the tube part and controls the operation of the prime mover is housed,
In a power tool comprising
A first switch disposed on the handle and electrically connected to the control unit;
A second switch that is disposed at a front lower portion of the cylindrical portion or a front end of the casing and is electrically connected to the control portion;
With
The control unit causes the prime mover to operate when both the first switch and the second switch are operated.   The said 2nd switch is each provided so that it can operate from the right-and-left both sides of a casing, and a control part operates a motor | power_engine by operating said 1st switch and any one 2nd switch. The power tool described in 1.

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