DE102004041466B4 - Electromotive actuator with control unit for intermediate position and control method - Google Patents

Abstract

Method for controlling an electromotive adjusting drive, in particular for furniture, which has an electric motor (11) actuated drive element (12) with limit switches (13, 14) and an intermediate switch (15) for fixing end and intermediate layers and by actuating a first Operating element (16) is moved in a first direction and by actuating a second actuating element (17) in a second direction, characterized in that a position of the intermediate switch (15) via a changeover contact of the intermediate switch (15) is queried and a switching state of the actuating elements (16, 17) via a switching contact (32) of the actuating elements (16, 17) is queried, wherein the intermediate switch (15) is bridged when an opened switching state of the intermediate switch (15) and at the same time an interruption of an actuation of an actuating element (16, 17) are detected, and the intermediate switch (15) is not bridged when a closed switching state of the intermediate switch (15) is detected.

Description

The invention relates to an electromotive adjusting drive, in particular for furniture, with an output element whose end and intermediate layers are determined by the adjustment influencing limit switch and at least one intermediate switch, and with a control unit with intermediate position control.

Electromotive adjusting drives for furniture are known in many different versions. They are used, for example, to adjust the backrests and foot parts of armchairs in their inclination. For this purpose, both linear drives and rotary drives are used. Both have in common that their travels or angles are limited by limit switches. These limit switches are actuated by actuating means, which are arranged on the respective output members, upon reaching the respective end position and can thus interrupt the power supply to the respective motor directly or indirectly.

The operation of such drives via operating buttons, which are arranged for example on a so-called manual control. If the drive has reached an end position, it is no longer possible to move the motor in the same direction with the respective operating button. Only one procedure in the opposite direction is possible.

It is known in certain furniture, such. B. in a stand-up chair, to arrange an additional limit switch between the two end positions. This is useful because a stand-up chair is extended in the one end position as a couch and in the other end position forms a highly-driven sloping seat as a stand-up. The intermediate position is in this case the normal sitting position, which should be a reproducible position of the chair. If such an adjustment drive now moves with an intermediate position from the direction of one of the two end positions in the direction of the seat position, then the drive automatically stops in the sitting position, even if the operating button remains pressed. After releasing this control button, it is possible to move the adjustment in any direction.

This function is realized in a known embodiment by means of a relay circuit in which special relays, so-called bistable relays, are used. Another possible solution describes the generic DE 298 20 233 U1 in which an additional operating button on the manual control is arranged for the intermediate position. A disadvantage of both versions, that due to the necessary relay control additional and expensive components are used, which additionally also disadvantageously occupy space. Since the field of application of such drives comprises furniture, in particular seating furniture, in which primarily a low installation space and a low price are required, the use of the known solutions is not possible or uneconomical. In the known embodiments described above, another disadvantage is that the control of the adjustment, which is often designed as a relay control, requires its own housing. To eliminate this extra space, there are known solutions without relay control, in which the motor current is switched directly from the manual control. A disadvantage of these solutions, however, is that they have no intermediate switch.

The document DE 199 21 344 A1 relates to a drive for adjusting with an electric motor and a circuit for starting and / or reversing the electric motor. The circuit comprises two limit switches, which are designed as a changeover switch.

The document DE 12 45 064 B discloses an electric Storen drive, in which in addition to two limit switches for completely stopping the Storenantriebs an intermediate switch is provided. The intermediate switch can be bridged by means of a switch to turn the blind drive again.

The document DE 202 12 615 U1 discloses an electric motor adjustment for adjusting a piece of furniture with a drive train, which acts on the adjustable furniture via an adjusting means. The drive train is driven by an electric motor. The adjustment has two limit switches, which cause a shutdown of the electric motor upon reaching their positions. Furthermore, a safety limit switch is provided, which is responsible in the event of a defective limit switch for switching off the electric motor. In one embodiment, a switching element is arranged parallel to the safety limit switch.

The object of the invention is to provide an electric motor adjustment, especially for furniture, which no longer has the disadvantages mentioned above and offers further advantages over the prior art.

This object is achieved in that the intermediate switch has a changeover contact, and that the control unit for the intermediate position control has at least one bridge switch and at least one control block.

Advantageous developments of the invention are contained in the subclaims.

A preferred embodiment of the invention provides that the intermediate position control is arranged on a control unit within the drive housing of the electromotive adjusting drive. This control unit contains the connections for the motor, the limit switches and the intermediate switch. Also can be plugged in from the outside: an operating unit, a power supply and optionally at least one additional auxiliary drive.

The intermediate position control consists of a bridge switch and a control block, which advantageously affects the bridge switch so that it is possible in the simplest advantageous manner to approach the intermediate position with the elecromotor adjustment drive from each direction. In this case, the operating button for the adjusting motor remain depressed, the adjusting motor is automatically switched off in the intermediate position. An additional operating button for the intermediate position is advantageously not required.

Intermediate switch is a changeover switch whose one contact path, which is closed during normal operation of the drive, is electrically bridged by the bridge switch. The bridge switch is in a preferred embodiment, a semiconductor device, preferably a transistor. In the bridge switch can continue to be arranged a current limiting element.

In a further embodiment of the invention, a sensor element is arranged in the bridge switch, which may be, for example, a temperature-sensitive resistor, a so-called PTC type. Thus, in a simple way, a monitoring of the bridge switch, for example, allows for overload.

The bridge switch has a control input connected to an output of the control block. This allows the bridge switch depending on the operating conditions of the electric motor adjustment by the control block are advantageously influenced.

This is possible because the control block has a first switching half-conductor and a second switching half-conductor, and has at least one input for a first interrogation connection and an input for a second interrogation connection. The two Schalthalbleiter are mutually formed in a known manner to a so-called flip-flop, an electronic circuit arrangement. The influence of this electronic switch is realized on the one hand by the first query connection, which signals the switching state of the controls of the manual control to the control block, and on the other hand by the second query connection, which signals the state of the intermediate switch the control block. This makes it possible that when the manual operation of the motor is turned off when it reaches the intermediate switch, wherein the bridge switch is locked by the control block due to these operating conditions. Now, when the operating button is released, the operating conditions that are signaled to the control block, and the control block gives an output signal to the bridge switch, which is thereby turned on. Since the bridge switch is parallel to the switched-off in this situation intermediate switch, can now drive by further actuation of any operating button of the adjustment in a desired adjustment.

In the embodiment in which the sensor element is, for example, a temperature sensor, this temperature sensor, which is preferably a PTC resistor, can be included in the circuit of the control block, wherein the output signal of the control block can advantageously be additionally influenced. If, for example, the adjusting motor is blocked in the intermediate position or overloaded by an excessive load, the control block recognizes this via the sensor element and can thus open the bridge switch again in a further embodiment, so that the motor is stopped again.

In a further embodiment is in the direction of travel of the adjustment, another changeover switch in front of the intermediate switch, which is actuated before reaching the intermediate switch of the output element of the adjustment. This changeover switch switches in this situation, a current limiting resistor in the motor cable, which is advantageously achieved that the adjusting drive is decelerated before reaching the intermediate switch and slowly continues to turn off by the intermediate switch. This can be done in one direction as well as in both directions. Preferably, this so-called braking resistor is formed by the already existing current limiting element of the bridge switch.

Through the use of transistors or suitable Schalthalbleitern for the bridge switch and the control block and a minimum cost of electronic components, it is possible to provide a particularly compact and economical adjustment. By using the current limiting element described above, for example, an advantageous monitoring of the motor starting current in conjunction with a suitable sensor element is possible.

The control unit within the motor housing of the electric motor adjusting drive further includes known protective elements, for example against overvoltages, which thus make the use of semiconductor devices for this application unproblematic.

The intermediate position controller with bridge switch and control block can be used for a variety of drives, not just the embodiment described herein.

It is also possible to arrange several intermediate positions by a respective intermediate switch with bridge switch and control block. Also, the number of auxiliary drives is not limited to one.

The switching semiconductors of the control block are charged only with a low switching current. Therefore, they can be used in a particularly small design. Since the switching semiconductor of the bridge switch conducts the motor current only for a short time, this semiconductor can also be correspondingly small in its dimensioning. It may also include an integrated protection element such as a stand-alone temperature protection circuit.

Thus, an electric motor adjustment for use in furniture with special restrictive conditions for the installation space and economy is created.

Of course, the application of the invention in connection with a double intermediate switch, as in
DE 295 04 987 U1 described, possible to eliminate a switching hysteresis due to a correspondingly long actuator.

• 1 eine schematische Darstellung eines beispielhaften elektromotorischen Antriebssystems mit einer Zwischenposition;
• 2 ein Schaltbeispiel, teilweise in Blockdarstellung, einer Zwischenpositionssteuerung; und
• 3 das Schaltbeispiel gemäß 2 in einer beispielhaften Ausführungsform.

Further details of the invention are described in the drawings with reference to an embodiment. It shows:

• 1 a schematic representation of an exemplary electric motor drive system with an intermediate position;
• 2 a switching example, partially in block diagram, an intermediate position control; and
• 3 the switching example according to 2 in an exemplary embodiment.

In the 1 is an exemplary electric motor drive system with two variable displacement drives shown schematically. A drive 2 , a so-called linear drive, includes a motor 11 , which moves via known gear types, a driven element 12 in the direction of its longitudinal axis back and forth. The output element 12 has actuating means in a known manner 30 , z. As a switching cam on, with which limit switch 13 . 14 . 15 be operated in the extended and in the retracted position of the output element 12. In the illustrated example forms a first limit switch 13 the extended end position and a second limit switch 14 the retracted end position. An intermediate switch 15 is at the position of an intermediate position.

Furthermore, the drive includes 2 a control unit 1 , on which a service 8th , a supply connection 9 and in this embodiment, an auxiliary terminal 10 are arranged. With the operation manual 8th is a control unit 4 with controls 16 . 17 . 18 . 19 connected. A power supply 5, on one side with a power cord 6 is connected to the electrical supply network is via another connection cable to the supply connection 9 the control unit 1 connected. At the additional connection 10 is via a connection cable 7 an auxiliary drive 3 connected, whose construction except for a connection unit 31 the drive 2 equivalent.

The operating instructions 8th , Supply connection 9 and the auxiliary connection 10 are usually designed as connectors, but may also be all or even partially designed as a fixed connection.

The control unit 1 preferably comprises a printed circuit board on which the terminals 8th . 9 . 10 with the engine 11 and the limit switches 13 . 14 . 15 electrically connected via conductor tracks. Furthermore, on the control unit 1 an intermediate position control and further known electrical and / or electronic components arranged, which are explained in more detail below.

The power supply 5 For example, is provided with a transformer, a rectification and a filter capacitor, so that the connection line between the power supply 5 and supply connection 9 at the drive 2 a harmless low DC voltage leads.

Applying the motor 11 with the supply voltage of the power supply 5 takes place in that by pressing a first control element 16 its switching contacts 32 on the control unit 4 the motor 11 in a certain polarity with the DC voltage of the power supply 5 is applied and rotates in a certain direction, wherein the output element 12 of the drive 2 retracts or retracts. By releasing the first operating element 16 the power supply to the engine 11 interrupted and the engine 11 stops. By pressing a second control element 17 on the control unit 4 , becomes the engine 11 with reverse polarity of the DC voltage of the power supply 5 acted upon, changing its direction of rotation, and the output element 12 in the opposite direction.

The switching contacts 32 can also be contacts of a relay.

A third operating element 18 and a fourth operating element 19 on the control unit are the auxiliary drive 3 assigned. Because the auxiliary drive 3 in its function to the drive 2 corresponds, the same reference numerals apply to identical components.

When operating a control element 16 . 17 (This also applies to the auxiliary drive 3 ) the motor moves 11 the output element 12 of the drive 2 in a certain direction until the actuating means 30 which is z. B. on the output element 12 is one of the limit switches 13 . 14 . 15 actuated. By pressing the first limit switch 13 or the second limit switch 14 is determined by the respective limit switch 13 . 14 the power supply to the engine 11 interrupted. The engine can be moved after reaching such an end position only in the opposite direction, as is known.

Will the intermediate switch 15 from the actuating means 30 pressed, then the engine 11 also stopped. This is necessary, for example, in adjustable rest chairs to achieve a certain seat position to be reproduced. After releasing the previously operated control element 16 or 17 It is possible by pressing any operating element 16, 17 to continue the drive in any direction. This function of the intermediate position control will be described below with reference to 2 explained in more detail.

2 shows a switching example of the control unit 1 with intermediate position control partly in block representation and with usual electrical / electronic switching symbols. Here, the same reference numerals of 1 for the same components.

The symbols for the controls 16 . 17 , the limit switch 13 . 14 and for the intermediate switch 15 are all shown in a non-actuated position.

On the control unit 1 is the supply connection 9 , which is shown here with the poles plus and minus. The supply connection 9 is with the operating instructions 8th connected to which the operator unit 4 with the controls 16 and 17 and their switch contacts 32 connected in a known manner and interconnected. Also is the connection configuration of the motor 11 with the limit switches 13 and 14 and bridge diodes 20 known.

The bridge diodes 20 in a likewise known manner ensure that at an actuated limit switch 13 . 14 An actuation of the engine is only possible in the opposite direction.

The intermediate position controller consists of the intermediate switch 15 , a bridge switch 22 and a control block 23 ,

In the current path of the positive lead of the supply connection 9 is the intermediate switch 15 arranged. The intermediate switch 15 is a so-called change-over switch with a common connection G , a normally closed contact nc and a normally open contact no ,

The intermediate switch 15 is through the bridge switch 22 bridged with the terminals x, y. The bridge switch 22 has a control terminal z, which with the control block 23 via a control connection 29 connected to its connection point b is the control block 23 is to the supply connection 9 connected, he is still standing with the switch contacts 32 via at least one first query connection 27 at its connection point a in electrical connection, and with the no contact of the intermediate switch 15 via a second query connection 28 with its connection c in electrical connection.

When operating the intermediate switch 15 opens the normally closed contact nc and interrupts the circuit to the engine 11 , which is thus stopped. At the same time the normally open contact no of the intermediate switch 15 closed and stands over the second query connection 28 with the control block 23 now in electrical connection. The electrical boundary conditions at the switch contacts 32 be through the first query connection 27 the control block 23 communicated. The control block prepares the processing of this information 23 a control signal which at its terminal b via the control connection 29 the bridge switch 22 is transmitted electrically at its connection point z.

As long as the previously operated control element 16 . 17 is still pressed, causes the signal at the connection point b of the control block, a blockage of the bridge switch 22 , so that the motor is still not supplied with supply voltage. When you release the previously operated control element 16 . 17 The electrical boundary conditions at the switch contacts change 32 which is via the first query connection 27 the control block 23 is communicated. The control block 23 now changes its signal at its terminal b, whereby the bridge switch 22 via the control connection 29 is turned on to its control input z. at a renewed actuation of a control element 16 . 17 bridges the now conductive bridge switch 22 the open, normally closed contact nc of the intermediate switch 15 and thus leaves the engine 11 start. Once the engine is running, the output element 12 Continue, so that the intermediate switch 15 is no longer actuated and the normally closed contact nc closes again. At this moment, the normally open contact no of the intermediate switch 15 opened again and signals this state via the second query connection 28 the control block 23 over the connection c.

Only in this time of engine startup, until the intermediate switch 15 is no longer actuated, the motor starting current flows through the bridge switch 22 , whereby this can be advantageously sized small.

It is particularly advantageous that the bridge switch 22 and the control block 23 work together on the control unit 1 and thus within the drive 2 are located. An additional control unit with a separate external control housing is not required.

In this switching example the 2 the entire motor current is directly via the operating unit 4 directed. It is of course possible that the switching contacts 32 the controls 16 . 17 which are shown here as a change contacts in a known manner, can be replaced by relay contacts. This is provided for example in another embodiment.

The switching example of 2 will be in the 3 explained in more detail with reference to an exemplary circuit.

In 3 there is the bridge switch 22 from a bridge semiconductor 24, which in this case may be a transistor. Its connection x, is with the plus line of the supply connection 9 connected. Another terminal of the transistor is via a current limiting element R1 , via port y with the normally closed contact nc the intermediate switch 15 connected. The connection z of the bridge switch 22 is a control input of the transistor.

The control block 23 becomes from a first Schalthalbbleiter 25 and a second switching semiconductor 26 formed, in this embodiment, the Schalthalbleiter 25 . 26 Transistors are. These two transistors are interconnected in a known manner so that, for example, results in a so-called flip-flop. This flip-flop has a control input c, which the second query connection 28 to the normally open contact no of the intermediate switch 15 forms. The first query connection 27 consists in this embodiment of two lines connected to the switch contacts 32 are connected. These first two query connections 27 are via connection points a, a'mit the control block 23 connected.

Furthermore, the control block 23 a connection points d, which in conjunction with a sensor element R2 which may be, for example, a PTC resistor in direct thermal communication with the current limiting element R1 or the bridge semiconductor 24 stands. Thus, a particularly advantageous monitoring of the motor current, and / or the bridge semiconductor 24 when starting the engine 11 possible from the intermediate position. This will cause the control block 23 influenced so that, for example, at a high motor current of the bridge semiconductor 24 over the control connection 29 is locked again and thus interrupts the motor current.

The function of the control block 23 is described below. An actuation of the first operating element 16 turns off the engine 11 by means of the switching contact 32 one. When reaching the intermediate switch 15 through the actuator 30 this is switched by this. This will be the closed contact nc of the intermediate switch 15 open, with the engine 11 is turned off. At the same time, the open contact no of the intermediate switch 15 closed. This preserves the second query connection 28 positive potential from the supply connection 9 , which now at the connection point c of the control block 23 pending. As long as the first control element 16 is actuated, lies at the switch contact 32 negative potential, at the switching contact 32 of the second operating element 17 on the other hand lies positive potential of the supply connection 9 as is known. The two-wire first polling connection 27 sets the potential occurring at the respective switching contact to the control block 23 via its connection points a, a '. While the engine is running 11 is the second switching semiconductor 26 switched through and the first Schalthalhalbleitleiter 25 blocked. It follows that the control connection 29 a potential across the connection point z to the base of the bridge semiconductor 24 sets, which locks it, and thus the engine 11 when reaching the intermediate switch 15 is switched off when switching.

The two Schalthalbleiter 25 and 26 of the control block 23 lock each other. Thus, the first Schalälbleiter 25 not be switched through.

Only when the previously operated first control element 16 is released again, and thus to the connection points a, a 'of the control block 23 this state is transmitted, locks the second Switching semiconductor 26 , and the first switching semiconductor 25 is switched through, because at this time the intermediate switch 15 is still switched and via its closed no-contact positive potential on the second query connection 28 located at the connection point c. The switching through of the first Schalthalhalbbleiters 25 causes the potential on the control link 29 changes so that the bridge semiconductor 24 is switched through. Because the bridge switch 22 represents a conductive connection and the intermediate switch 15 bridged, can now by pressing a control element 16 . 17 the motor 11 restart in the desired direction of rotation.

In the event that the actuating means 30 no short switching cam, but a longer switching nose is how out DE 295 04 987 U1 is known, two intermediate switches 15 provided, which are interconnected in parallel. In this case, the actuating means must both intermediate switch 15 Press, so that the drive stops at the intermediate position.

In a further embodiment, the adjustment speed of the engine 11 reduced shortly before reaching the intermediate position. This is achieved in an advantageous manner in that between the nc contact of the intermediate switch 15 and the operating instructions 8th another changeover switch like the intermediate switch 15 is used. This changeover switch is before reaching the intermediate switch 15 from the actuating means 30 actuates and switches via its normally open contact a series resistor or current limiting element, which advantageously also the existing current limiting element R1 can be in the motor current path. This ensures that the engine 11 advantageously before reaching the intermediate position runs at a lower speed.

In the presence of an additional drive 3 this is about the additional connection 10 to the control unit 1 connected, the control unit 1 for the auxiliary drive 3 a second bridge switch 22 and a second control block 23 may have, if the auxiliary drive 3 also has an intermediate switch.

The bridge switch 22 and the control block 23 can also be used for other drive configurations, their use is not limited to the case described here. Furthermore, the embodiment described here with transistors as a bridge semiconductor 24 and switching semiconductors 25 . 26 consist of other components. It is understood that the circuit design further protection components against high voltage pulses of the motor 11 etc. has.

The exemplary embodiment described here is not limited to linear drives; the application can, of course, as is easily understood, also be used, for example, for rotary drives with limit switches.

LIST OF REFERENCE NUMBERS

1

control unit

2

drive

3

accessory drive

4

operating unit

5

power supply

6

power cable

7

connection cable

8th

operation connection

9

supply terminal

10

Second line

11

engine

12

output element

13

first limit switch

14

second limit switch

15

between switch

16

first operating element

17

second operating element

18

third operating element

19

fourth operating element

20

bridge diode

22

bridge switch

23

control block

24

Bridge Semiconductor

25

first switching semiconductor

26

second switching semiconductor

27

first query connection

28

second query connection

29

control connection

30

actuating means

31

connection unit

32

switch contacts

a-d, x-z

connection points

g, nc, no

contacts

0, I

switch positions

R1

Current limiting element

R2

sensor element

Claims (10)

Method for controlling an electromotive adjusting drive, in particular for furniture, which has an electric motor (11) actuated drive element (12) with limit switches (13, 14) and an intermediate switch (15) for fixing end and intermediate layers and by actuating a first Operating element (16) is moved in a first direction and by actuating a second actuating element (17) in a second direction, characterized in that a position of the intermediate switch (15) via a changeover contact of the intermediate switch (15) is queried and a switching state of the actuating elements (16, 17) via a switching contact (32) of the actuating elements (16, 17) is queried, wherein the intermediate switch (15) is bridged when an opened switching state of the intermediate switch (15) and at the same time an interruption of an actuation of an actuating element (16, 17), and the intermediate switch (15) is not bypassed d, when a closed switching state of the intermediate switch (15) is detected. Electromotive adjusting drive, in particular for furniture, for performing the method according to Claim 1 , with an output element (12) actuated by an electric motor (11), whose end and intermediate positions are determined by the adjusting drive influencing limit switches (13, 14) and at least one intermediate switch (15), wherein the electric motor (11) by a first operating element (16) in a first direction and by a second operating element (17) in a second, reverse direction is controlled, and with a control unit (1) with intermediate position control, characterized in that the intermediate switch (15) has a changeover contact, and that the Control unit (1) at least one bridge switch (22) and at least one control block (23), wherein the bridge switch (22) to at least one contact path of the intermediate switch (15) is electrically connected in parallel and has a control input (z), which with an output (B) of the control block (23) is electrically connected, wherein the control block (23) has a first input (a) via a first interrogation connection (27) is connected to a switching contact (32) of the operating elements (16, 17) and has a second input (c) which is connected via a second interrogation connection (28) to a normally open contact (no) of the interposer ( 15) is connected, wherein the control block (23) is formed so that the bridge switch (22) is open without this closing output signal at the output (b) when the first or second operating element (16, 17) of the intermediate switch (15 ) is reached and is open, and a bridge switch (22) closing output signal at the output (b) is applied when the open-connected intermediate switch (15), the operating element (16, 17) is no longer actuated. Electromotive adjusting drive to Claim 2 , characterized in that the bridge switch (22) comprises a bridge semiconductor (24). Electromotive adjusting drive to Claim 2 or 3 , characterized in that the bridge switch (22) has at least one current limiting element (R1). Electromotive adjusting drive according to one of Claims 2 to 4 , characterized in that the control block (23) has a first Schalthalbeltleiter (25) and a second Schalthalbleiter (26). Electromotive adjusting drive to Claim 5 , characterized in that the switching semiconductors (25, 26) are transistors. Electromotive adjusting drive to Claim 5 or 6 , characterized in that the bridge switch (22) has a sensor element (R2) which influences the output signal of the control block (23). Electromotive adjusting drive according to one of Claims 2 to 7 , characterized in that in the adjustment of the drive (2, 3) in front of the intermediate switch (15) at least one further switch with changeover contact is arranged at a distance which switches a braking resistor in the current-carrying line of the motor (11) when actuated. Electromotive adjusting drive to Claim 8 , characterized in that the braking resistor is formed by the current limiting element (R1). Electromotive adjusting drive according to one of Claims 2 to 9 , characterized in that when using two intermediate switches (15) for hysteresis influencing an actuating means (30), these two intermediate switches (15) are connected in parallel.

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