JPS61100381A - Electric tool - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a hand-held power tool such as a vibrating drill.

[Background technology]

15. When working with a hand-held power tool such as an electric drill, the handle may get in the way of the worker depending on the work location. That is, as shown in FIG.
If you work near the tool body 71, the handle 73 holding the grip 72 will come into contact with the wall surface 70, making it impossible to work.

As shown in the figure, when attempting to drill from the wall surface 70 to point io, point g.

<2. As a result, a part of the handle 73 comes into contact with the wall surface 70, making it impossible to work. Here, 11 is the distance from the axis of the bit 74 to the outermost point of the handle 73;
1/2 of f2 and the thickness of the back of the hand when gripping the grip 72! 3, and ff11=A2/2+f3. 12 is about 3011.13 is about 40m, so
11 is about 45 dragons and cannot be used near a wall below 451s.

In this case, with conventional power tools, the tool body is approximately 900 mm
It is rotated to face sideways, and is used in a working posture in which the left hand grips the auxiliary handle 75 from above and the right hand grips the grip 72 from below. At this time, the left hand determines the drilling position, and the right hand supports the tool body and presses the tool body 71 against the wall surface 70 to be drilled, but the right hand is unnatural and it is not possible to obtain enough thrust to press the tool body 71 against the wall surface 70. In addition, there was a drawback of poor workability.

[Purpose of the invention]

An object of the present invention is to provide a power tool that can be easily used in large corners of walls as well as other locations.

[Disclosure of the invention]

The power tool of the present invention has a grip rotatably attached to the rear end of the tool body having a bit at the tip thereof so as to be rotatable at least approximately 90 degrees.

Since the grip is rotatable in this way, even in large corners of walls, by rotating the grip to an appropriate angle relative to the tool body, it is easy to obtain thrust without the hand holding the grip touching the wall surface. It can be seen in its natural state.

First Embodiment An embodiment in which the present invention is applied to a vibrating drill is shown in FIGS. 1 to 3. In FIG. A grip 4 is rotatably attached to the rear end. The tool body 1 is
A battery storage section 6 containing a battery 5 is located near the rear end, and a motor 7 and a mechanism section 8 are housed inside. Tool body l
An auxiliary grip 9 is detachably attached to the vicinity of the tip. A switch 10 installed in the grip 4 from the battery 5
Electric power is supplied to the motor 7 through the. 11 is its lead wire.

The mechanism section 8 provides rotation and reciprocating motion to the chuck 3 by the rotation of the motor 7, and is configured as follows. The chuck 3 is attached to an output shaft 12 that is rotatably and movably supported by the tool body 1, and the rotation of the motor 7 is controlled by gears 13, 14, a transmission shaft 15, and a gear 16.
17 to the output shaft 12. An eccentric cam 19 is connected to the intermediate shaft 15 via a bevel gear mechanism 18, and rotation of the eccentric cam 19 causes a driver 21 to reciprocate within a guide cylinder 22 via a crank arm 20. Drive element 2
1 is connected to a hammer 24 by a coil spring 23, and a drive element 2
The hammer 24 strikes the output shaft 12 by one reciprocating motion.

The attachment part of the grip 4 will be explained. The grip 4 and the tool body 1 are in contact with each other at rotation surfaces 25 and 26 such that they can rotate and slide freely. The zero-rotation shaft 27 inserted into the hole is prevented from being pulled out by a retaining ring 28. The zero-rotation shaft 27 is provided with a through hole 29, and a lead wire 11 connects the battery 5, motor 7, and switch 10. is passing through. Although the rotational axis of the rotational shaft 27 and the rotational axis of the bit 2 are parallel to each other, it is preferable that the distance between the two rotational axes be as short as possible.

Operation of the first embodiment When using in a large corner of a wall, do as shown in Figure 3.

First, rotate the tool body 1 approximately 90 degrees from an upright position so that it is horizontal as shown in the figure, and then rotate the grip 4 downward approximately 90 degrees.
' Rotate it to the state shown in the same figure and in Fig. 2. As a result, the right hand 30 with its thickened grip 4 is in a natural state in which it can support the tool body l and easily obtain thrust. Further, the right hand 30 does not come into contact with the wall surface 31, resulting in good workability. The left hand 32 grasps the auxiliary grip 9. In addition, the auxiliary grip 9
It is also possible to directly support the tool body 1 with the left hand without attaching the grip 4 to the tool body 1. Return to use.

As a result, unlike the case where the grip 4 is fixedly installed at the angle shown in FIG. 2, it is possible to avoid a decrease in usability at a location away from the wall surface.

Second Embodiment FIGS. 4 to 8 show a second embodiment of the present invention. This example shows the mounting structure of the grip 4 and the auxiliary handle 9.
The second embodiment is different from the first embodiment in the switch 33, and the rest is the same as the first embodiment. ? +! The auxiliary handle 9 will be described later, and the mounting structure of the grip 4 will be explained. A rotary support tube 35 is installed on the 1&end surface of the tool body 1.
is integrally provided in a protruding manner, and a cylindrical spring constant adjustment knob 36 is rotatably fitted onto the rotation support cylinder 35 . The front opening edge 37 of the grip 4 is rotatably attached to the spring constant adjustment knob 36, and therefore the grip 4 is attached to the tool body l.
It is rotatably connected to.

26' This is the rotating surface that the spring constant adjustment knob 36 comes into contact with. A coil spring 38 for absorbing image pickup is interposed between the grip 4 and the end wall 35a of the rotation support tube 35. spring y7
A variable spring constant ring 39 is screwed onto the inner periphery of the four-adjustment knob 36 with a threaded portion 40 (FIG. 6). As shown in FIG. 6, the spring constant variable ring 39
It has a pin 42 that engages with a guide groove 41 formed in 5. However, when the spring constant adjustment knob 36 of the spring constant 111 is rotated, the spring constant variable ring 39 moves back and forth in the axial direction (arrow Q direction). The variable spring constant ring 39 covers a part of the coil spring 38, and the length of the variable spring variable ring 39 changes as it moves back and forth.

In this manner, in this embodiment, the grip 4 is connected to the tool body 1 via the coil spring 38, so vibrations are less likely to be transmitted to the grip 4, improving usability. Further, since the spring constant of the coil spring 38 is variable as described below, it can be adjusted to an appropriate vibration-preventing state depending on the drilling material and the drilling location.

That is, when the spring constant adjustment knob 36 is turned, the spring constant variable ring 39 screwed thereon moves forward and backward, and the length covering the coil spring 38 changes. The coil spring 38 is compressed by pressing the focus 2 against the object to be drilled when the tool is used, and at this time the coil spring 38 expands in diameter. However, the diameter of the portion inside the variable spring constant ring 39 cannot be expanded, and the action of the spring is lost in that portion. Therefore, the spring constant is given by nD3, but as the number of turns n becomes smaller, the spring constant k changes. G is the transverse elastic modulus, d is the diameter of the strand, D
is the average diameter of the coil spring 38. In addition, coil spring 3
The diameter of the wire 8 may not be uniform but may be changed gradually, thereby making the spring characteristics non-linear.

Explain the anti-vibration effect. When the tool is used, the hammer 24 vibrates at a frequency of f. Here, if the spring constant of the coil spring 38 of the grip 4 is k and the weight of the tool body l is W, the natural frequency 10 of the tool body l is (=1/2π・kg/w g: Acceleration of gravity and Here, the vibration transmissibility of (/(o) has the relationship shown in FIG.
>2, the photographing motion of the tool body l will not be transmitted to the grip 4. Therefore, the operator can stably perform drilling work for a long time without having his hands covered. Also,
The impact force generated by the impact of the hammer 24 can be effectively used for work. Furthermore, since the T and lya 5 are also vibration-proofed by the coil spring 38, the internal cells are prevented from moving and short-circuiting, and the life of the battery 5 is also extended.

Here, the pressing force when using a tool varies depending on the direction in which the tool is used. When drilling a hole in a ceiling, etc., a small push acts as a force to force the tool upward, and when drilling a hole laterally or downward in a wall or ground, a large push acts as a force. Also, depending on the material, hard concrete must be pressed with a strong force in order to make effective use of the 1 hour impact force, while soft concrete does not require a large impact force, so it can be pressed with only a weak force. The magnitude of the pressing force F corresponds to the magnitude of the motor load T, which in turn corresponds to the rotation speed of the motor 7, that is, the drive frequency f. Therefore, for the frequency f, the natural frequency ro is f / r o <
If the spring constant k of the coil spring 38 is set using the spring constant adjustment knob 36 so that the spring constant k is 0.5, a good anti-@ effect can be achieved.

Further, the number of rotations of the motor 7, that is, the frequency f, changes depending on the depth of the hole. As the depth of the hole increases, the frequency f
becomes smaller. When the hole becomes deep, in order to prevent the focus 2 from breaking and to reduce the large load (the deeper the hole, the greater the F!J friction between the side of the bit and the concrete), press the It is better to keep the force F small.However, if a nonlinear spring is used in which the spring constant k changes depending on the amount of deflection δ, the pressing force is Cal-(δ-small)-(k-small), and the pressing force is large- (δ-large) - (k-large), so for r-small due to the hole becoming deeper, fo-smaller than k-smaller even if the pressing is cull,
While obtaining a vibration-proofing effect, impact force can be used effectively, making the tool easier to use.

The auxiliary handle 9 is detachable from the tool body l.

? ! When the auxiliary handle 9 is attached, the first contact ring 44 provided on the inner surface of the A-type handle band 43 comes into contact with the contact terminal 45 on the power supply side, creating a closed circuit as shown in FIG. At this time, the switch 33 of the auxiliary handle 9 and the switch 10 of the grip 4 are connected in series. When removing the auxiliary handle 9, the second contact ring 46 is connected to the contact terminal 45.
and passes through the closed circuit shown in Figure 8. Second contact ring 46
contacts the contact terminal 45 due to its elasticity, but when the auxiliary handle 9 is attached, the contact ring 45 is pushed by the contact ring pressing protrusion 44a on the inner surface of the handle band 44, and the contact terminal 45
move away from 47 is a mounting hole for the auxiliary handle 9, and 11'
is the lead wire.

In this way, the switch 10.33 is provided on both the grip 4 and the auxiliary handle 9, and the motor 7 will not operate unless both switches 10.33 are turned on. Otherwise, it will not work and is safe.

In addition, when the auxiliary handle 9 is attached, the motor 7 does not operate unnecessarily, and the tool body latch due to sudden vibration.
There is no danger of it falling.

Third Embodiment FIGS. 9 to 13 show a third embodiment of the present invention. In this example, a tool main body 1 includes a motor 7 and a mechanism section 8.
and a circuit section 5', and a chuck 3 is attached to the tip. Additionally, an auxiliary grip 9 is attached near the tip. Note that the same parts as in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted. A rotation surface 48 is formed on the wall surface of the rear end of the tool body 1, and a rotation support shaft 49 protrudes from the rotation surface 48.

The grip 4' has a bearing 50, and the rotation support shaft 4 is supported by the bearing 50.
99 rotations freely 2 outside 11 L 7 t,' 6・1 rotation +
A through hole 51 is formed in the center of 1491, through which the lead wire 11 passes, connecting the switch 10 and the circuit section 5'.
and the motor 7 are electrically connected. In addition, in the circuit section 5', the 0-rotation support shaft 49 and the bearing 50, in which an electric circuit for controlling the rotational speed of the motor 7 is incorporated, have concave portions and convex portions on the circumference, as shown in the figure. The 0
A rotating surface 48 and a rotating surface 52 at the end of the grip 4'.
53 is stepped so that the grip 4' can rotate smoothly with respect to the tool body 1. It is desirable that the distance between the rotation axis of the bit 2 and the axis of the rotation support shaft 49 be as small as possible.
This is because if the drilling direction of the bit 2 matches, the workability will be improved.

The rotation support shaft 49 and the bearing 50 are shown in FIGS. 11 to 13.
As shown in the figure, a steel ball 54, a lock spring 55, a steel ball guide groove 56, a spring insertion hole 60, a tenth hole 57.
, a 20th hole 58, and a 30th hole 59 are formed. Thereby, the rotation of the grip 4' is restricted to the left and right 90' with respect to the tool body l, and can be locked at the normal position, left 900, and right 900. The rest is the same as the first embodiment.

Note that the rotation restriction and locking means of the grip 4' in the third embodiment are similarly provided in the first embodiment and the second embodiment.

Furthermore, in each of the embodiments described above, the battery 5 is arranged offset from the axis of the bit 2, but the battery 5 may be arranged on the axis of the bit 2. In this case, the center of gravity of the tool body l becomes It is close to the axis of the bit 2, which reduces the holding force of the tool body 1, making it easy to use.

〔Effect of the invention〕

The power tool of the present invention has the effect that the grip can be placed in a position that is easy to hold and use, such as in a large corner of a wall or in other locations, and good workability can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the first embodiment of the present invention, FIG. 2 is a cutaway front view of the grip in a rotated state, FIG. 3 is an explanatory diagram showing the usage state from above, and FIG. Embodiment 2 is a sectional view, FIG. 5 is a cutaway front view of the grip in a rotating state, FIG. 6 is a perspective view of the spring constant adjusting means of the coil spring for the grip, and FIG. 7(A) is the same. FIG. 7(B) is an electrical circuit diagram with the auxiliary handle attached, FIG. 7(B) is an electrical circuit diagram with the auxiliary handle removed, FIG.
The figure is a sectional view of the third embodiment, FIG. 1O is a cutaway front view of the grip in a rotating state, FIG. Oblique? Fig. f1 and Fig. 13 are sectional views of the same means, and Fig. 14 is an explanatory view of the use of the conventional example. DESCRIPTION OF SYMBOLS 1... Tool body, 2... Bit, 4.4'... Grip, 5... Battery, 7... Morph, 8... Mechanism part, 9... Auxiliary handle, 10... ...Switch, 27
... Rotating axis bI5 Fig. 11 Fig. 12 I:17 Fig. 14

Claims (4)

[Claims] (1) A power tool in which a grip is attached to the rear end of the tool body with a bit at the tip so as to be able to rotate at least approximately 900 rotations. (2) The power tool according to claim (1), wherein the grip is formed into a substantially rectangular frame shape. (3) The power tool according to claim (1), wherein the end surface of the rear end of the tool body is a rotating surface on which the grip slides. (4) The electric tool according to claim (1), wherein the rotation axis of the grip is disposed substantially coaxially with the bit.