DE102010034377A1 - Electrical switch for hand-guided electric power tool e.g. electric drilling machine, has printed circuit board accommodating control device that controls and/or regulates electric motor, and switching contact mechanically fastened to board - Google Patents

Abstract

The switch has a contact system (7) including a switching contact and a fixed contact, and an actuating body (6) switchingly acting on the contact system in a position. A printed circuit board (PCB) (16) accommodates a control device (9) for controlling and/or regulating an electric motor (2). The switching contact is mechanically fastened to the PCB and electrically connected with a conductive strip and/or a conductor surface (17) on the PCB. The switching contact is formed by a contact spring that directly solders an end of an electrically contactable area on the PCB.

Description

The The invention relates to an electrical switch according to the preamble of claim 1, 2 or 3.

Such Switches are used for power tools, for example Hand-held power tools, such as electric drilling machines, Rotary hammers, electric screwdrivers o. The like., Used.

From the DE 197 08 939 A1 an electrical switch for a power tool with an electric motor is known, wherein the switch has a manually adjustable between an initial and an end position actuator. If the actuator is moved from the starting position, a contact system of the switch is switched on to start an electric motor of the power tool. The actuator is also operatively connected to a potentiometer which emits a voltage corresponding to the adjustment of the actuator. The potentiometer thus serves as a signal means for generating a the adjustment of the actuator associated signal, which is represented in this case by the electrical voltage. This signal is supplied to a control device accommodated on a printed circuit board in the switch, the control device operating, controlling and / or regulating the electric motor as a function of this signal. For example, the control device sets the speed of the power tool according to the adjustment made by the user of the actuator. If the actuator in the end position, so one of the bridging of the control device serving contact system is turned on, so that the electric motor is operated at full voltage. The actuator thus acts in each case a position, namely the output and the end position, switching on the respective contact system, wherein the contact system has a switching contact and a fixed contact.

at Hand-held power tools are thus to a large extent Switches and / or switching systems with electrical and / or electronic Additional functions are used, the printed circuit boards with or without electronic components in and / or on the mechanical switch housing include. The basic structure of such a power tool switch consists of a mechanical switch-on, one of this electrically downstream electronics for controlling or regulating the tool functions, such as speed, torque and / or direction of rotation, a mechanical Bypass contact for bridging the electronics in "Full or Max. Speed" mode and an optional one mechanical direction of rotation switch. The variety of these contact systems together with the circuit board leads to a complex as well large-scale power tool switch.

Of the Invention is based on the object, the electrical switch such that the switch designed to be more compact is.

These Task is in a generic electrical Switch by the characterizing features of claim 1, 2 or 3 solved.

At the switch according to the invention is at least one the switch contacts mechanically attached to the circuit board. additional Alternatively, the switching contact is electrically connected to a Conductor and / or a conductor surface on the circuit board in Connection. As a result, the circuit board at the same time as a carrier used for at least one switching contact in the switch, what the otherwise required support structures for the switch contacts omitted in the switch. Advantageously reduced thereby the size of the switch.

One Such switching contact can also be used for use an electrical switch, although the switching contact in and / or out of contact with the fixed contact to the switching Acting in the contact system is movable, but this on an actuator, in particular on a manual adjustable actuator, is omitted. For example In this case, the switching contact can be electromotive, electromagnetic, due to external and / or internal influence or be movable in any other way. According to the invention in turn, the switch contact mechanically attached to the circuit board and / or is electrically connected to a conductor track and / or a conductor surface on the circuit board.

Further Embodiments of the invention are the subject of the dependent claims.

Around to contact the switch contact in a compact way electrically stands the switching contact expediently electrically with a conductor track and / or a conductor surface in the Type of contact pad on the circuit board in conjunction. In this case It also makes it possible that the fixed contact of a further conductor track and / or another conductor surface is formed in the manner of a contact pad on the circuit board.

In a further embodiment, the switching contact may be formed by a mechanically resilient contact spring in the manner of a leaf and / or compression spring. It is advisable that the contact spring soldered by means of one end to a first electrically contactable point directly on the circuit board, clamped to the circuit board, pressed into a circuit board hole o. The like. Mechanically and / or electrically contacting is attached to the circuit board. The switching contact expediently interacts with a second, electrically contactable point of the printed circuit board as a fixed contact switching. For the interaction of the switching contact with the fixed contact is expediently the other end of the contact spring. The contact spring may have an additional contact for good contacting, wherein the additional contact may be attached to the other end of the contact spring.

In Another embodiment is by mechanical action on the Switching contact arranged by means of an external to the circuit board, with the actuator operatively connected component the contact is opened and / or closed in the contact system. The external component can according to the wishes of the User as a pusher, slider, button or as another Be configured actuator. For this purpose, on the component movable between the printed circuit board and the contact spring, on the Contact spring acting approach be located. This is the result Switching contact against its spring force by means of the approach of the fixed contact liftable by moving the lug in between. Otherwise is the switching contact on the fixed contact by means of its spring force.

In a training, especially in a switch without Actuator offers, consists of the switching contact a bi-metal material. This is due to the temperature-dependent Self-movement of the switch contact an opening and / or closing a circuit allows. This circuit is used again for heat regulation in the switch. For example This can cause the opening of a critical circuit to turn off the power tool or close it a cooling circuit for a fan o. The like. Be enabled. Damage to the Power tool due to overload will be on this Way prevented.

The Actuator is manually between an output and an end position adjustable. Will the actuator moved from the starting position, so is a contact system of the switch switched on to start an electric motor of the power tool. The actuator is still in operative connection with a signal device for generating a the adjustment of the Actuator associated signal. This signal will a control device supplied in the switch, wherein the Control device, the electric motor in dependence of operates, controls and / or regulates this signal. For example the control device sets the speed, the torque o. The like. of the power tool according to the adjustment path of the user made adjustment of the actuator a. reaches the actuator in the end position, so is the bridging the control device serving contact system is turned on, which the electric motor is operated at full voltage. The actuator thus acts in one position at a time, namely the starting point as well as the end position, switching to the respective contact system one.

Instead of a contact system for bridging the control device can also be a so-called "non-bypass" system be used. Not least new and constantly improved Battery technologies and the associated need for realization of electronic monitoring functions, for example of current, voltage and / or temperature by measuring these values, regulations to partial or full shutdown functions, as well Display functions pose growing and also new requirements to the switch system. Special requirements are required the mechatronic packing density and the performance because of the mentioned shutdown functions of the mechanical by-pass contact omitted. In another switch concept One waives mechanical power contacts by the switching functions be taken over by controlled power electronics components, so that this is the so-called fully electronic Switch acts. There are switching and / or braking functions Optionally also fully electronic feasible. With all these Switch designs, especially these "electronically dominated" switch designs, It may be necessary to use certain switching functions, such as the partial or complete switching on and / or off the electronics or Components of electronics, with complete galvanic To realize separation.

For this purpose, the state of the art shows the use of wiper elements which "glide" over corresponding printed circuit board areas with switching pads arranged there or else the use of small contact systems which are arranged in or on the switch housing externally of the printed circuit board and are electrically connected to the electronics. When using grinders, there is the problem that there is no galvanic isolation between the pulse width modulation (PWM) potentiometer and the circuit to be switched. The variant of an additional auxiliary contact has the disadvantage of the necessary additional contacting this auxiliary contact externally of the circuit board. Partial power contacts are also used to switch the electronics, but with great restrictions on the switching point and lack of galvanic isolation. The electrical switching via microprocessor is also state of the art for this purpose, which, however, is problematic in terms of the "leakage current problem" and with regard to the risk of fault susceptibility. to Avoiding these problems and instead of such elaborate embodiments, it is again here to turn to realize these switching functions by means of additional mechanical switching elements, which according to the invention by mechanically attached to the circuit board and / or electrically with a conductor and / or a conductor surface on the circuit board in Connection standing switching contacts are formed.

In usual Way, the switch may have a housing. preferably, is the circuit board together with the switching contact and / or the control device in the housing. If desired, can However, the circuit board together with the switching contact and externally in Regarding the case to other convenient Be located in the power tool. Conceivable is the use of the inventive switching contact also in external, in the grip, for example below or above the Switch, located electronics. The operation of the Switching contact takes place in this case also mechanically, wherein This additional function activation, if necessary, by the machine operator by mechanical push of a button in the lower or upper area of the power tool he follows.

Conveniently, the signaling device has a grinder, the grinder is arranged on the actuator. Preferably, the Grinder arranged on the slider-like component, such that the Grinder is movable by means of the actuator. Of the Grinder acts on manual movement of the actuator by the user with at least a portion of the adjustment path associated contact surface electrically contacting the Generating the signal together. This is the contact surface designed in the manner of a potentiometer and is located as a resistance surface on the circuit board. The signal that from a corresponding to the respective tapped potentiometer Control voltage is supplied to the control device. According to the signal as a setpoint then the electric motor operated in dependence thereon.

For a particularly preferred embodiment is to be determined below.

One or even more such additional switching elements for the corresponding switching functions of the switch are directly mechanical and / or electrically attached to or on the circuit board. This will be preferably a mechanically resilient contact spring, for example a leaf or compression spring, with or without additional contact directly soldered to the PCB, clamped to the PCB, pressed in printed circuit board holes or by another known Joining connection technology mechanically and / or electrically attached directly to the circuit board. The mechanical design is done in such a way that this switching element at a second, electrically contactable point of the circuit board with a specific Contact force is applied. By mechanical action from the outside, in particular by a component arranged externally of the printed circuit board, like a pusher, a slider, a button or something similar Actuator, this contact can be opened.

optional This switching element can consist of several individual elements. Such an embodiment is dependent on the switching behavior, the forces, the mechanical conditions and dimensions or also by the number of switching points and / or current paths.

Also can the switching element in the "original state" designed open be. The closing of the contact path then takes place a component arranged externally of the printed circuit board. The switching element Consequently, as an opener and / or possibly also as normally open act. The switching and / or contact forces can from the switching element itself, for example when using resilient metallic elements, or of corresponding ancillary equipment, For example, by spring elements, are applied. The non-latent Contact point can be designed according to the electrical requirements be, for example, bare metal, electroplated or with an additional contact made of a special contact material. Of the Contacting or opening can optionally by a relative movement takes place transversely to the contacting vertical, for the contact safety by a mechanical cleaning of the contact point too improve. The actuation of the switching element takes place usually from the outside by means of direct or indirect mechanical linkage, for example by means of a pusher, a slider, button or similar actuator.

at Use of a bi-metal material can its temperature-dependent "Eigenbewegeung" to the opening or to close a circuit. Consequently can this self-movement for the purpose of heat regulation be used in the switch system. examples for this are the opening of a critical circuit or closing a cooling circuit.

Such, attached directly to or on the circuit board switching element can be mounted on a printed circuit board located in the circuit board. Conceivable is a use even with external, in the grip, for example, below or above the switch, located electronics. The operation is also done here mechanically. This additional function activation may be performed by the machine operator via mechani pressing a button in the lower or upper area of the power tool.

The particular advantages of the invention are that the direct attachment of the switch contact and / or on the circuit board for a compact and reliable mechatronic Design leads. It is a smaller footprint than necessary in previous solutions.

The PCB is simultaneously handled with the contact, resulting in Simplifications in the manufacture of the switch leads. The installation and / or attachment of the switch contact to the circuit board can be considered a simpler and cheaper Handlötprozeß ausgestalten. The invention The system is also tolerance-insensitive. Furthermore are electronics for operating the power tool with lesser ones Complexity than previously possible when switching off of the power tool with leakage currents "close to zero" omitted can be.

Furthermore is the integrability of the invention Switching contacts in today's switch designs possible, which saves costs for a new development. There in the case of cordless tools here the negative battery connection (B-) is switched, turns off the electronics thus of great advantage. Compared to the electronic Shutdown, this variant is much safer. The precise Shutdown by mechanics avoids the otherwise with the electronics occurring problems. Especially with regard to the "fully electronic Switch ", in which the switching off in terms of safety regulations represents a problem, the inventive Solution greatly simplify the circuits.

One Embodiment of the invention with various developments and embodiments is shown in the drawings and will described in more detail below. Show it

1 1 is a schematic illustration of a power tool with an electrical switch, wherein the housing of the power tool is shown partially broken away;

2 one out the contact system of the switch 1 comprehensive detail view, with the contact system off, and

3 a detail view like in 2 , wherein the contact system is turned on.

In 1 is a power tool 1 with an electric motor 2 for driving a tool 3 to see. It may be a cordless and / or mains power tool. Exemplary is in 1 a cordless drill as a power tool 1 shown using a supply voltage from a mobile energy storage 8th is operated in the manner of a battery. Of course, it can be in the power tool 1 also to another electric drill, a hammer drill, an electric screwdriver, a grinder, a saw, a planer, an angle grinder o. The like. Act.

In the case 4 of the power tool 1 is a switch 5 with a switch housing 13 arranged. The desk 5 is so in the case 4 recorded that a manually movable by the user actuator 6 of the switch 5 in the manner of a pusher, button, actuator o. The like. From the housing 4 protrudes. The desk 5 owns a contact system 7 on which the actuator 6 acts to switch, so that the power supply from the energy storage 8th for the power tool 1 , in particular for the operation of the electric motor 2 , by means of the actuator 6 can be switched on and / or off by the user.

Finally, the switch includes 5 an electrical circuit arrangement for controlling and / or regulating the electric motor 2 by means of pulse width modulation (PWM). The example, a microcontroller or a microprocessor containing circuitry serves as a control device 9 for speed change of the electric motor 2 according to the position of the user moved, adjustable between an initial and an end position actuator 6 and is conveniently located in the switch housing 13 , This is the actuator 6 with a signaling device 21 for generating a the adjustment of the actuator 6 associated signal in operative connection. The signaling device 21 then acts with the controller 9 for operation, namely for controlling and / or regulating the electric motor 2 , How its speed, torque o. The like., Depending on the adjustment of the actuator 6 together.

As in further 1 is visible on the case 4 a workfield lighting 10 arranged, with the help of which the working area for the tool 3 is illuminatable as support for the user. The power supply for the working area lighting 10 also takes place from the energy storage 8th , in the present case via the control device 9 , which works as a pulse width modulation circuit for this purpose. This will be the workfield lighting 10 via one of the supply voltage from the energy store 8th fed pulse width modulation signal 11 operated, bringing the brightness of the workfield lighting 10 Accordingly, can be adjusted as desired. This leads to a current path 12 from the controller 9 to Ar beitsfeldbeleuchtung 10 to the power supply, wherein the pulse width modulation signal 11 over the current path 12 for working area lighting 10 is directed.

As based on the 2 or 3 can be seen, is the contact system 7 on a circuit board 16 in the switch housing 13 , The circuit board 16 further serves to receive the control device 9 , The actuator 6 acts in a position switching on the contact system 7 one, and indeed is in the in 2 shown starting position of the actuator 6 the contact system 7 switched off as well as in the 3 shown movement position of the actuator 6 the contact system 7 switched on. The contact system 7 has a movable switching contact 14 as well as a fixed contact 15 on. The switching contact 14 of the contact system 7 is mechanically on the circuit board 16 attached.

For electrical contacting is the switching contact 14 at one end electrically with a conductor track and / or a conductor surface 17 in the manner of a contact pad at a first electrically contactable location on the circuit board 16 in connection. The fixed contact 15 is also of a conductor track and / or a conductor surface in the manner of a contact pad on the circuit board 16 formed, bringing the switching contact 14 by means of its other end with a second, electrically contactable point of the circuit board 16 as a fixed contact 15 interacting switching. The switching contact 14 is formed by a mechanically resilient contact spring in the manner of a leaf and / or compression spring. This is the switching contact 14 due to its spring force on the fixed contact 15 on, as based on 3 can be seen, in which case the contact is closed. The contact is open as based on 2 is seen by an approach 18 between the circuit board 16 and the contact spring 14 is moved while the switching contact 14 against the spring force of the fixed contact 15 takes off. The approach 18 is located at one with the actuator 6 operatively connected component 20 in the manner of a slider, so that by mechanical action by means of the external to the circuit board 16 arranged slider 20 contacting in the contact system 7 opened and / or closed. To further improve the contact, the contact spring 14 at the other end, one of the interaction with the fixed contact 15 serving additional contact, but this is not shown in detail. The contact spring 14 is for mounting on the circuit board 16 by means of a pin 19 pressed into a circuit board hole. Just as well, the contact spring 14 in any other way to the circuit board 16 clamped, clamped, directly on the circuit board 16 soldered o. The like. Mechanically and / or electrically contacting on the circuit board 16 to be appropriate.

The signaling device 21 is designed in the manner of a potentiometer and has a grinder 22 and a contact surface 23 on. The contact surface 23 is in the manner of a potentiometer track as on the PCB 16 located resistor surface configured. The grinder 22 is on the slider 20 attached so that the grinder 22 by means of the actuator 6 is movable, and acts with the at least a portion of the adjustment path of the actuator 6 associated contact surface 23 electrically contacting to generate the signal together. The respective signal depending on the adjustment of the actuator 6 Then, as already mentioned, the control device 9 for the corresponding operation of the electric motor 2 fed.

In a further embodiment, which, however, also not shown further, there is the switching contact 14 from a bi-metal material. Its temperature-dependent proper motion thus allows the opening and / or closing of a circuit, this circuit for heat regulation in the switch 5 serves. By opening a critical circuit, the switch can 5 be turned off to the power tool 1 and / or the switch 5 to protect itself from overheating. Likewise, thereby closing a cooling circuit is possible, for example, an additional fan for the power tool 1 and / or the switch 5 to be put into operation.

As described, such a switching element 14 directly on or in the switch housing 13 located circuit board 16 appropriate. The switching element 14 However, it can also be used for other internal and / or external circuit boards and / or electronic assemblies. So is also a use with external, in the grip, below or above the switch 5 located electronics possible. The operation is also done mechanically, for example, this additional function activation by the machine operator by mechanical button pressure in the lower or upper part of the power tool 1 ,

The invention is further not limited to the described and illustrated embodiment. Rather, it also encompasses all expert developments within the scope of the invention defined by the claims. Thus, such a switch can be used not only in mains (AC) powered power tools operating, for example, with phase-angle control and / or battery-powered (DC) power tools operating, for example, with PWM control in other electrical equipment supplied by a voltage source, as garden tools, kitchen appliances o. The like., Use find.

LIST OF REFERENCE NUMBERS

1

power tool

2

electric motor

3

Tool

4

casing (from power tool)

5

switch

6

actuator

7

Contact system

8th

energy storage

9

control device

10

Cockpit lighting

11

Pulse-width modulation signal

12

current path (for working area lighting)

13

switch housing

14

Switching contact / contact spring / switching element

15

fixed contact

16

circuit board

17

conductor surface (for switching contact)

18

approach

19

spigot (to contact pen)

20

Member / slide

21

signaling device

22

grinder

23

contact area

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19708939 A1 [0003]

Claims (10)

Electric switch, in particular for a power tool ( 1 ) with an electric motor ( 2 ), as for an electric drill, a hammer drill, an electric screwdriver o. The like., With an actuator ( 6 ), with a switch contact ( 14 ) as well as a fixed contact ( 15 ) contact system ( 7 ), wherein the actuating member ( 6 ) in a position switching to the contact system ( 7 ), and with a printed circuit board ( 16 ), in particular for receiving a control device ( 9 ), for example, for controlling and / or regulating the electric motor ( 2 ), characterized in that the switching contact ( 14 ) mechanically on the circuit board ( 16 ) is attached. Electric switch, in particular for a power tool ( 1 ) with an electric motor ( 2 ), as for an electric drill, a hammer drill, an electric screwdriver o. The like., With an actuator ( 6 ), with a switch contact ( 14 ) as well as a fixed contact ( 15 ) contact system ( 7 ), wherein the actuating member ( 6 ) in a position switching to the contact system ( 7 ), and with a printed circuit board ( 16 ), in particular for receiving a control device ( 9 ), for example, for controlling and / or regulating the electric motor ( 2 ), characterized in that the switching contact ( 14 ) electrically with a conductor track and / or a conductor surface ( 17 ) on the printed circuit board ( 16 ). Electric switch, in particular for a power tool ( 1 ) with an electric motor ( 2 ), as for an electric drill, a hammer drill, an electric screwdriver o. The like., With a one switching contact ( 14 ) as well as a fixed contact ( 15 ) contact system ( 7 ), wherein the switching contact ( 14 ) in and / or out of contact with the fixed contact ( 15 ) is movable, and with a printed circuit board ( 16 ), in particular for receiving a control device ( 9 ), for example, for controlling and / or regulating the electric motor ( 2 ), characterized in that the switching contact ( 14 ) mechanically on the circuit board ( 16 ) and / or electrically connected to a conductor track and / or a conductor surface ( 17 ) on the printed circuit board ( 16 ). Electric switch according to claim 1, 2 or 3, characterized in that the fixed contact ( 15 ) of a further conductor track and / or another conductor surface on the printed circuit board ( 16 ) is formed. Electrical switch according to one of Claims 1 to 4, characterized in that the switching contact ( 14 ) is formed by a contact spring, that preferably the contact spring ( 14 ) by means of one end thereof at a first, electrically contactable point directly on the printed circuit board ( 16 ) soldered to the circuit board ( 16 ) clamped, pressed into a circuit board hole o. The like. Mechanically and / or electrically contacting on the circuit board ( 16 ) is mounted, that further preferably the switching contact ( 14 ) with a second, electrically contactable point of the circuit board ( 16 ) as a fixed contact ( 15 ), in particular by means of the other end of the contact spring ( 14 ) cooperating, and that even more preferably the contact spring ( 14 ), in particular at the other end, has an additional contact. Electrical switch according to one of claims 1 to 5, characterized in that by mechanical action by means of an external to the printed circuit board ( 16 ), with the actuator ( 6 ) in actively connected component ( 20 ), which is designed in particular in the manner of a slide, the contacting in the contact system ( 7 ) is opened and / or closed, and that preferably on the component ( 20 ) between the printed circuit board ( 16 ) and the contact spring ( 14 ) movable, on the contact spring ( 14 ) approach ( 18 ) is located, such that the switching contact ( 14 ) against its spring force by means of the approach ( 18 ) from the fixed contact ( 15 ) can be lifted and otherwise on the fixed contact ( 15 ) abuts by means of its spring force. Electrical switch according to one of Claims 1 to 6, characterized in that the switching contact ( 14 ) consists of a bi-metal material, so that by the temperature-dependent proper movement of the opening and / or closing of a circuit is made possible, in particular this circuit for heat regulation in the switch ( 5 ) serves. Electrical switch according to one of claims 1 to 7, characterized in that the actuating member ( 6 ) is adjustable between an initial and an end position that preferably the actuating member ( 6 ) with a signaling device ( 21 ) for generating a the adjustment of the actuator ( 6 ) signal is operatively connected, and that further preferably the signaling device ( 21 ) with the control device ( 9 ) for operation, in particular for controlling and / or regulating the electric motor ( 2 ), As the speed, torque o. The like., Depending on the adjustment of the actuator ( 6 ) cooperates. Electrical switch according to one of Claims 1 to 8, characterized in that the signaling device ( 21 ) a grinder ( 22 ), that preferably the grinder ( 22 ) on the component ( 20 ) is arranged so that the grinder ( 22 ) by means of the actuator ( 6 ) is movable, that further preferably the grinder ( 22 ) with an at least one portion of the adjustment associated with the contact surface ( 23 ), in particular one in the manner of a Potentiometerbahn designed and optionally on the circuit board ( 16 ), electrically contacting for generating the signal cooperates, and still further preferably the signal of the control device ( 9 ) for the operation of the electric motor ( 2 ) is supplied in response to the respective signal. Electrical switch according to one of Claims 1 to 9, characterized in that the switch ( 1 ) a switch housing ( 13 ), and that preferably the circuit board ( 16 ) and / or the control device ( 9 ) in the switch housing ( 13 ) is located.

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