JPH11123669A - Electromotive tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give an influence to an operational parameter whithout changing the grip position of an electromotive tool. SOLUTION: This electromative tool has a driving motor having a driving shaft to drive a tool receiver, and it is provided with a start control electronic device to give an influence to the operational parameter of the electromotive tool as well as to start control the driving motor, and in this case, a regulating means to give an external influence to the operational parameter is provided to the start control electronic device correspondently. The regulating means 36 consists of a power sensor 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power tool having a drive motor provided with a drive shaft for driving a tool receiving portion, and to control start of the drive motor and influence start parameters of the power tool. A device is provided, in which case the start-up control electronics are associated with adjusting means for externally affecting the operating parameters.

[0002]

2. Description of the Related Art A power tool of this type is known. For example, a group of power tools such as drills, drill hammers, turning saws and the like are known, and it is desired to change operating parameters in these power tools. For example, it is known to adjust the rotational speed of an electric tool in advance. For this purpose, a start-up control electronics with externally operable adjusting means is arranged correspondingly to the drive motor. This adjusting means consists, as is known, of an adjusting wheel incorporated in the handgrip of the power tool, with which the rotational speed is predetermined via the activation control electronics.

A disadvantage of this case is that, in one aspect, it is necessary to change the gripping position of the power tool in order to operate the adjusting wheel.
Must be used for the operation of the adjusting wheel, on the other hand the adjusting wheel is guided through the casing opening of the casing of the power tool,
As a result, uneconomical sealing means must be provided, or the interior of the casing must be receptive to fouling, in particular dust.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to avoid the above disadvantages.

[0005]

The object is achieved according to the invention in that the adjusting means comprises a force sensor.

[0006]

According to the invention, it is possible to influence the operating parameters simply, in particular without changing the grip position of the power tool. The adjusting means for adjusting or controlling the activation control electronics comprises a force sensor, which is advantageously provided by the operating force of a part of the operator's hand gripping the handgrip of the power tool when operating the power tool. It is possible to adjust or control the activation control electronics by loading a force sensor. For this, it is not necessary to change the grip position, so that the power tool can be operated reliably.

In another advantageous embodiment of the invention, an operator
A force sensor is incorporated in the handgrip within a range where the thumb of the hand gripping the handgrip can reach. In particular, if the force sensor is arranged directly below the mantle of the casing, the force sensor is operated by applying a point-like force action to the casing. According to a further advantageous embodiment of the invention, the housing is designed to be thin in the region of the force sensor, so that the operation of the force sensor is possible via the housing, in particular without providing a housing opening. It is possible.

[0008] It is furthermore advantageous that the adjusting means is designed as a force sensor, so that mechanical loads, especially vibrations, which occur during normal use of the power tool, do not cause a change in the position of the adjusting means. .

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Examples will be described in detail.

In the drawing, a casing 10 of a power tool 12 is partially shown. The power tool 12 can be, for example, a hand-held drill, a drill hammer or the like. Casing 10 includes a casing portion 14 for receiving a drive motor (typically an electric motor).
And a casing part 16 for forming a handgrip 18. Both casing parts 14, 16
May consist of one or more parts. The handgrip 18 has a through grip opening 20 in which an on / off switch 24 is located.
Operating means 22 are arranged. Via the on / off switch 24, the supply voltage of the motor is connected or disconnected.

The power tool 12 further includes a start control electronic device 2.
The activation control electronics are mounted, for example, in the installation space of the handgrip 18.
An adjustment wheel 28 is optionally associated with the activation control electronics 26. The adjusting wheel 28 projects at least to one side from the handgrip 18 and serves for the operation of a potentiometer, not shown in detail, of the activation control electronics 26.

A force sensor 30 is also incorporated in the handgrip 18, the sensor surface 32 of which is directed to a jacket 34 of the housing part 16. In the area of the force sensor 30, the outer jacket 34 can be made thinner than in other areas of the casing part 16.
The force sensor 30 is connected to the activation control electronics 26 via an electrical connection line 36a, shown in broken lines. The force sensor 30 is provided with an adjusting means 36 of the activation control electronics 26 for externally affecting the operating parameters of the power tool 12.
Is formed.

The force sensor 3 inside the hand grip 18
The zero position means that when the operator grips the handgrip 18, the finger of the hand is penetrated into the through grip opening 20, and the force sensor 30 is simultaneously operated by the thumb without changing the position of the hand. Have been selected to be able to.
For this purpose, the force sensor is largely integrated in the area above the handgrip 18, as can be seen from the drawing. Of course, for example, a hand grip 18
If it is possible to operate the force sensor with the thumb ball of the hand while holding, the force sensor 30 can be arranged at another position.

The function of the power tool 12 is as follows.

When the power tool 12 is turned on via the on / off switch 22, the drive motor is turned on by the start control electronic device 2.
6 to the supply voltage. However, the start-up control electronics 26 initially prevents the drive motor from starting by means of appropriate circuit components. Sensor surface 32 of force sensor 30
, The high-speed rotation of the drive motor is controlled. Depending on the magnitude of the operating force F applied (via the operator's thumb), the rotational speed of the drive motor changes between a stopped state and a maximum rotational speed. It is advantageous if a minimum operating force has to be applied in order to guarantee a low starting rotation of the drive motor. In this way, since the minimum operation force F must be relatively accurately applied to the force sensor 30, accidental high-speed rotation of the drive motor is avoided. By changing the operating force during use of the power tool 12, the rotation speed of the drive motor can be changed steplessly. In particular, the pulsating response to the user allows a very precise speed adjustment to be adapted to the respective requirements or wishes.

The setting of the various maximum values of the rotational speed can additionally be effected by means of the adjusting wheel 28. In short, according to the adjustment of the adjustment wheel 28, various rotation speed ranges are adjusted with the same operating force.

The storage element of the start-up control electronics 26 for automatically maintaining a drive shaft speed proportional to the operating force F when the operating force F acting on the sensor surface is maintained constantly for a selectable period of time. 38 is helpful. For example, a predetermined rotational speed can be selected via a continuous increase in the operating force F, and this rotational speed is automatically maintained by maintaining the operating force F corresponding to this rotational speed. At the same time, the force sensor 30 can be "released".
The erasing of the storage element 38 is performed by a new load of the force sensor 30 by the operation force F and / or by operating the on / off switch 22.

Of course, in an embodiment different from the above embodiment,
Instead of the rotation speed of the power tool 12, the torque of the power tool 12 can be adjusted. Furthermore, the force sensor 30 offers the possibility to carry out an inquiry as to whether the power tool 12 is kept in the correct position. Force sensor 3 by user
Only when 0 is operated for the first time, the start of operation of the power tool 12 is released via the activation control electronics 26. This achieves a lock, especially against accidental activation of the power tool 12.

[Brief description of the drawings]

FIG. 1 is a partial view of a power tool according to one embodiment of the present invention.

[Explanation of symbols]

10 casing, 12 electric tool, 14, 16
Casing part, 18 hand grip, 20 through grip opening, 22 operating means, 24 on / off switch, 26 activation control electronics, 28 adjustment wheel, 30 force sensor, 32 sensor surface, 3
4 mantle, 36 adjusting means, 36a electrical coupling lead, 38 storage element, F operating force

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Werner Houser Germany Rheinfelden-E Hitterdingen Mohnstrasse 8 (72) Inventor Wolfgang Hirschburger USA Chicago West Peterson 4300 (72) Inventor Andreas Zimmermann Germany Stuttgart Hoy Steigstrasse 67 B

Claims (8)

[Claims] 1. A power tool having a drive motor having a drive shaft for driving a tool receiving portion, comprising: a start control electronic device for controlling a start of the drive motor and affecting an operation parameter of the power tool. In this case, the starting control electronic device is provided with adjusting means for externally affecting operating parameters, and the adjusting means (36) comprises a force sensor (30). An electric tool characterized by the above-mentioned. 2. The power tool according to claim 1, wherein the force sensor is integrated in the handgrip of the power tool. 3. The power tool (12), wherein the force sensor (30) comprises:
2. A housing part (16) forming a handgrip (18) of the housing is arranged directly under the jacket.
Or the power tool according to 2. 4. The power tool according to claim 1, wherein the sensor surface of the force sensor is directed toward the mantle. 5. The method according to claim 1, wherein the jacket is formed thinner in the area of the force sensor than in the housing part surrounding the area. The power tool according to claim 1. 6. A force sensor (3) which is used by an operator with the hand holding the handgrip (18) without changing the position of the hand.
0) so that the force sensor (30) can be operated
The power tool according to any one of claims 1 to 5, wherein a power tool is disposed. 7. An operation force (F) maintained constantly.
Detecting a signal emitted from the force sensor (30) in response to
A storage element (38) for automatically maintaining the operating parameters corresponding to the constant operating force (F) when the operating force (F) is constant for a selectable time is arranged in the activation control electronics (26). Claim 1
The power tool according to any one of claims 1 to 6. 8. The activation control electronics (26) has a corresponding adjustment wheel (28), which adjusts the operating range of the force sensor (30) for influencing operating parameters. The power tool according to any one of claims 1 to 7, wherein the power tool is adjustable in advance.