DE102016116257B3 - Control device for a pneumatic tool and use of the control device - Google Patents

Abstract

A control device (1) for a pneumatic tool (2), in particular for a polishing tool, is disclosed. The control device (1) comprises a cylinder (20) with an inflow side (24) and an outflow side (25) for compressed air. A magnet (23) is arranged in the axial direction (A) between a starting position (S) and an end position (E) movable in the cylinder (20). A solenoid valve (22) is arranged on an outer wall (21) of the cylinder (20) in the region of the end position (E) of the magnet (23). The solenoid valve (22) supplies a control signal to the time valve (60), so that a time interval preset at the time valve (60) is started.

Description

The present invention relates to a control device for a pneumatic tool. In particular, the control device comprises a supply line for compressed air, in which a first pneumatic valve is provided. Furthermore, a time valve is fluidly connected to the first pneumatic valve such that the supply line to the pneumatic tool can be interrupted by means of the first pneumatic valve.

Furthermore, the present invention relates to the use of the control device for a pneumatic tool in a system for repairing paint damage in a motor vehicle.

The German patent application DE 10 2009 005 217 A1 describes a system for providing quantitative process control of finesse polishing based on feedback to the operator as to whether he is meeting the one or more predetermined key control characteristics. One or more sensors provide data to a controller, the controller providing feedback to the operator regarding his operator compliance with the KCCs and disabling operation in the event of operator defiance with the intention of promoting the correct operator procedure and an operator error, if any faulty painted surface is polished to prevent. The proposed system requires not only the pneumatic connection from the compressed air supply to the tool but also an electrical connection to the tool. For example, warning lights go on and the switch is locked. Especially the electrical installation causes considerable costs and makes it difficult to carry out subsequent changes to the installation.

The German utility model DE 298 12 477 U1 discloses an actuator valve assembly for a pneumatic tool to operate it. The "power strokes" exerted by the pneumatic tool can either be rectilinear, in which case it is a pneumatic hammer. In a compressed air screwdriver, however, the power surges take place in the circumferential direction as torque surges. The purpose of carrying out a series of force impulses is to divide up the energy input required for a certain energy input, usually by overcoming friction, for better meterability. A pneumatic hammer may, for example, be the driving in of parts in a recess, in the case of a pneumatic screwdriver, the tightening of screws up to a certain limit torque.

The German Utility Model DE 20 2010 004 957 U1 describes a fluid control valve system for a pump control, with a controllable by a translationally movable piston rod of the pump control valve spool, which is displaceable between two extreme positions. The control valve system comprises a plunger which presses under pressure and which engages in a step detent field connected to the control valve slide.

The document DE 691 07 871 T1 is the part of the European patent validated in Germany EP 0 441 514 B1 , Here is a compressed air operated Paketierwerkzeug for clamping and securing a plastic Paketierbandes disclosed. The tool has a device for connecting the tool to a source of compressed air for a pneumatic actuator for contracting and connecting said Paketierbandes and a manually operated, normally closed valve between the drive and compressed air source. The Paketierwerkzeug further consists of a timing circuit, which ensures the expiry of a variable and presettable operating time for the shutdown of the compressed air supply to the drive. The timing circuit consists of a first line between the manually operated and normally closed valve and said compressed air source. A second conduit is provided between the compressed air source and the manually operated, normally closed valve. A third conduit is provided between the manually operated, normally closed three-way valve and an adjustable throttle check valve. A fourth line is provided between the adjustable throttle check valve and the pressure accumulator. An air-operated, normally open, three-way valve is arranged in the first line between the compressed air source and the drive. The valve has a pneumatic actuator which is connected to the compressed air reservoir and actuated by the pressure built up in the accumulator and closes as a result of this actuation. Thus, the compressed air supply of the drive is interrupted after a preset time from manual opening of said manually operated and closed at rest three-way valve.

The U.S. Patent 3,093,114 discloses a valve unit which is connected via a pressure hose to the tool. The tool is operated via a pressure switch. Furthermore, a Bowden train is provided, which responds to a trigger on the tool. Disadvantage is that with the tool a pressure hose and a Bowden train are connected. This increases the installation costs and the risk of accidents.

The US patent application US 2009/0055028 A1 discloses a pneumatic operated screwdriver. An electrical control is connected via corresponding lines with the screwdriver. Further, a regulator for the compressed air is provided, which is also connected to a hose with the tool. Disadvantage is that with the screwdriver, a pressure hose and an electrical line are connected. This increases the installation costs and the risk of accidents.

The German translation DE 698 22 371 T2 of the European Patent EP 0 887 560 B1 discloses a timing of a binding tool. The tying tool is a hand held, pneumatically actuated tool that provides adjustable control of the air driven engine. Thus, the amount of tension that secures and secures to the plastic strapping tool securing various packages, articles, pallets and the like is limited.

The pneumatic tools (pneumatic polishing machines) for the repair of paint damage (dust or other inclusions) are used after painting the motor vehicles in the factory. The pneumatic tools must be switched off during the polishing process after a predetermined time interval, otherwise the surface to be polished is overheated or the polishing paste used is consumed. For the controlled shutdown of the pneumatic tool, a control device is necessary. In the event that the control device is electrically formed, electrical installations must be made, which cause a high planning effort and increased costs.

The invention has for its object to provide a control device for a pneumatic tool, which is inexpensive and easy to install, thereby reducing downtime of the control device and the accident risk.

This object is achieved by a control device for a pneumatic tool comprising the features of claim 1.

The control device for a pneumatic tool comprises a supply line for compressed air, in which a first pneumatic valve is provided. A time valve of the control device is designed such that, in cooperation with the first pneumatic valve, it can interrupt the supply line to the pneumatic tool. The first pneumatic valve in the supply line is interrupted when a preset time has elapsed at the time valve. The control device comprises a cylinder with an inflow side and an outflow side for compressed air. In the cylinder, a magnet is movably arranged in the axial direction between a start position and an end position. On an outer wall of the cylinder, a solenoid valve in the region of the end position of the magnet is arranged. The solenoid valve provides a control signal to the timer valve when the solenoid is in the end position so that a time interval preset by the timer valve for the shutdown of the controller is startable.

In the control device according to the invention, a damping element between the inflow side of the cylinder and the magnet may be provided. Furthermore, a limiting element between the magnet and the outflow side of the cylinder may be provided.

According to one embodiment of the control device according to the invention, the damping element may be a spring. The limiting element may also be a spring. Both springs can contribute to a restoring force for the magnet in the starting position.

According to a possible embodiment, the damping element may be an elastic plastic component which is attached to the inflow side. The plastic component comprises for example the material FIBROFLEX ^®, which is a polyurethane rubber, and is used in the present invention in the form of a damping disk. The limiting element between the magnet and the outflow side is a spring which simultaneously provides a restoring force for the magnet in the starting position. In addition to the spring, a rigid rod may be connected to the magnet. The rigid rod cooperates with a stop on the outflow side of the cylinder when the magnet is in the end position. The stopper is preferably made of a plastic material. One possibility is the material "S" ^® , which is produced on the basis of a pure ultrahigh-molecular low-pressure polyethylene.

According to a further preferred embodiment, the damping element is a resilient plastic component, which is attached to the inflow side of the cylinder. The limiting element may be formed as a rigid rod, which cooperates with a stop on the outflow side of the cylinder when the magnet is in the end position. With the magnet, a guide element may be connected, wherein the rigid rod projects beyond the guide element. At at least three points of contact, the guide element is slidably guided on an inner wall of the cylinder. Here, too, the plastic component consists of the material "S" ^® , which clearly exceeds the requirements of DIN 16972. The original material "S" ^® belongs to the most successful material group among industrial plastics. In particular, the original material "S" green ^{® has} become established in the plastics industry and is used everywhere where technically efficient plastic is needed. The original material "S" green ^® is synonymous with good sliding properties, high wear resistance and long service life.

According to a further embodiment, a second pneumatic valve is provided in addition to the cylinder with the magnet for actuating the solenoid valve of the control device, which is fluidly connected to the time valve and the first pneumatic valve. Thus, from the second pneumatic valve, a control signal of the time valve can be received at the expiration of a preset time interval. The first pneumatic valve locks the supply line to the pneumatic tool by means of a control signal from the second pneumatic valve.

According to another embodiment, a logic time valve is fluidly connected to the first pneumatic valve and the time valve, wherein a re-release of the flow of compressed air from the central compressed air supply to the pneumatic tool on the logic time valve is adjustable via a switch-on delay.

Furthermore, a pneumatically adding preselector counter can be provided, which is fluidly connected to the time valve via a third pneumatic valve, so that a shutdown of the pneumatic tool occurs at a predefined number of cycles. The renewed switching on of the pneumatic tool is only possible again when the control device has been reset.

For resetting, a reset valve fluid may be connected to the supply line and at least to the preset counter, wherein upon actuation of a reset button of the reset valve, the accumulated number of cycles is reset on the preset counter. In addition, with the reset valve, a backwashing of the components of the control device is possible. This has the advantage that abrasion or dirt particles are discharged from the control device.

Particularly advantageous is the use of the control device for a pneumatic polishing tool in a system for repairing paint damage that has arisen in a motor vehicle during its painting. The controller requires little installation effort, can be retrofitted at any time and is long-term stability.

In the following, embodiments of the invention and their advantages with reference to the accompanying figures will be explained in more detail. The proportions in the figures do not always correspond to the actual size ratios, as some shapes are simplified and other shapes are shown enlarged in relation to other elements for ease of illustration. Showing:

1 a schematic view of a housing for the control device in conjunction with a pneumatic tool;

2 a schematic view of the circuit diagram of the purely pneumatic control device for a pneumatic tool;

3A and 3B a sectional view of a possible embodiment of the cylinder for actuating a solenoid valve, wherein the starting position and the end position of the axially movable in the cylinder magnet is shown;

4A and 4B a sectional view of another possible embodiment of the cylinder for actuating a solenoid valve, wherein the initial position and the end position of the axially movable in the cylinder magnet is shown;

5 a top view of the magnet, as shown in the in 4A and 4B embodiment shown in the cylinder is used; and

6 a schematic view of a system for repair of paint damage, which uses the control device according to the invention.

For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure.

In 1 is a schematic view of a housing 4 for the control device (not shown here) in conjunction with a pneumatic tool 2 shown. The interior of the housing 4 , in which the control device is located, is via a door 6 accessible. The door 6 is with a handle 7 to open the case 4 Mistake. In the case 4 leads a single supply line 11 for the compressed air, for example, from a central compressed air supply 19 (please refer 2 ) is made available. From the case 4 performs a single derivative 12 , via which by means of a flexible line 8th the passing through the control device compressed air to the pneumatic tool 2 is directed. In the embodiment shown here is the pneumatic tool 2 one for polishing paint on motor vehicles. The pneumatic tool 2 has a polishing pad for this purpose 9 , which by means of Compressed air is set in rotary motion. However, the polishing tool should not be construed as limiting the invention since the present invention also applies to other pneumatic tools 2 can be used. Outside the case is a reset button 10 provided with a backwashing of the control device can be performed. The control device is connected according to pneumatically.

The schematic diagram of the pneumatic control device 1 for the pneumatic tool 2 is in 2 shown. For the operation of the pneumatic tool 2 is compressed air from a central compressed air supply 19 over the only supply line 11 the control device 1 fed. The compressed air passes inside the control device 1 by means of a supply line 13 from the supply line 11 to the derivative 12 , The compressed air enters the supply line 13 to a first pneumatic valve 30 and from there to a cylinder 20 , From the cylinder 20 the compressed air reaches the discharge 12 which eventually became the pneumatic tool 2 leads. The cylinder 20 is on an outer wall 21 a solenoid valve 22 assigned. With the solenoid valve 22 can one in the cylinder 20 in the axial direction A displaceable magnet 23 (Please refer 3 or 4 ). If the magnet 23 the position of the solenoid valve 22 achieved, is in the solenoid valve 22 triggered a switching process. The switching process becomes a time valve 60 actuates the flow of compressed air from the central compressed air supply for a preset time interval 19 to the pneumatic tool 2 releases. After the preset time interval has elapsed, a second pneumatic valve is received 40 a signal from the timer valve 60 , The second pneumatic valve 40 supplies a signal to the first pneumatic valve 30 , then the flow of compressed air to the pneumatic tool 2 locks. The sliding magnet 23 in the cylinder 20 then returns to the starting position, so that the solenoid valve 22 is no longer actuated. Only with a renewed flow of compressed air to the pneumatic tool 2 becomes the magnet 23 in the cylinder 20 moved again and the solenoid valve 22 pressed (see 3 and 4 ).

After the preset time interval has elapsed, a logic time valve is received 50 a signal, and the re-release of the flow of compressed air from the central compressed air supply 19 to the pneumatic tool 2 is for the on logic time valve 50 set switch-on delay interrupted. This has the advantage of being an operator of the pneumatic tool 2 Switch off the pneumatic tool even in environments heavily loaded with noise 2 detected.

There is also a preselection counter 70 , which is formed pneumatically adding, provided. The preselection counter 70 gets from the time valve 60 via a third pneumatic valve 45 a signal, so that the number of cycles (shutdowns of the pneumatic tool 2 by the control device 1 ) can be counted. Switching off the pneumatic tool 2 after a predefined number of cycles, one will start with a preset counter 70 reached to be set number of cycles. Only when the operator of the pneumatic tool 2 at a reset valve 80 the reset button 10 is pressed, the count of the preset counter 70 reset and the pneumatic tool 2 is ready for use again. The preselection counter 70 has the task to indicate to the operator when reaching the preset number of cycles that, for example, the polishing pad of the pneumatic tool 2 to be changed. Further, by pressing the reset button 10 also a backwashing of the control device 1 achieved what happens at the controller 1 has a cleansing effect.

In the supply line 13 for the compressed air are branches 15 intended. From the branches 15 lead pressure lines 14 to some components of the controller 2 and the reset button 10 , The cable cross section of the supply line 13 is greater than the line cross section of the respective pressure lines 14 , Furthermore, in the pressure lines 14 further branches 16 provided to all components of the control device 2 to supply with the system pressure.

3A and 3B show a sectional view of a possible embodiment of the cylinder 20 for actuating a solenoid valve 22 , The solenoid valve 22 is on the outer wall 21 of the cylinder 20 intended. 3A shows the starting position of the cylinder 20 in the axial direction A movable magnet 23 , In the starting position is located on the cylinder 20 no pressure on. 3B shows the end position of the cylinder 20 in the axial direction A axially movable magnet 23 , This position is on the cylinder 20 a pressure on and the magnet 23 is with the solenoid valve 22 in operative connection. At the inflow side 24 of the cylinder 20 is a damping element 26 provided so that the magnet 23 not against the inflow side 24 of the cylinder 20 beats when the flow of compressed air through the cylinder 20 is interrupted. Between the magnet 23 and an outflow side 25 of the cylinder 20 is at least a limiting element 27 provided so that the magnet 23 at a predefined position with respect to the magnet 23 comes to a halt when the compressed air on the cylinder 20 is applied. In the embodiment shown here is the damping element 26 a feather 32 , The boundary element 27 is also a spring 33 that is between the magnet 23 and the outflow side 24 of the cylinder 20 is arranged. Although in the description of this embodiment of the cylinder 20 the damping element 26 a feather 32 and the delimiter 27 a feather 33 should not be construed as limiting the invention.

In the embodiment described here are damping element 23 a spring and the limiting element 27 one spring each 33 or 33 , both of which provide a restoring force for the magnet 23 deploy to the starting position S. The feather 33 that the boundary element 27 is in terms of their spring force dimensioned such that they have a counterforce to that in the cylinder 20 represents flowing compressed air when the magnet 23 in the end position E is. In addition to the spring 33 can be a rigid rod 34 (please refer 4B ) with the magnet 23 be connected. By means of the rigid rod 34 can be ensured that the end position E of the magnet 23 in any case, when the rigid rod is reached 34 at the stop 35 on the outflow side 25 of the cylinder 20 is applied.

4A and 4B show a sectional view of a possible further embodiment of the cylinder 20 for actuating a solenoid valve 22 , The solenoid valve 22 is on the outer wall 21 of the cylinder 20 intended. 4A shows the starting position of the cylinder 20 in the axial direction A movable magnet 23 , In the starting position is located on the cylinder 20 no pressure on. 4B shows the end position of the cylinder 20 in the axial direction A axially movable magnet 23 , This position is on the cylinder 20 a pressure on and the magnet 23 is with the solenoid valve 22 in operative connection. At the inflow side 24 of the cylinder 20 is a damping element 26 provided so that the magnet 23 not against the inflow side 24 of the cylinder 20 beats when the flow of compressed air through the cylinder 20 is interrupted. Between the magnet 23 and an outflow side 25 of the cylinder 20 is at least a limiting element 27 provided so that the magnet 23 at a predefined position with respect to the magnet 23 comes to a halt when the compressed air on the cylinder 20 is applied.

In the embodiment shown here is the limiting element 27 a rigid rod 24 that when the magnet 23 in the final position E, with a stop 35 on the outflow side 25 of the cylinder 20 interacts. To guide the magnet 23 and the weight increase is the magnet 23 with a guide element 36 Mistake. The rigid rod 24 dominates the guide element 36 and also with the magnet 23 be firmly connected. In the embodiment of the cylinder described here 20 is its installation in the control device 1 such that when in the case 4 built-in control device 1 the cylinder 20 is oriented substantially in the direction of gravity and gravity alone provides the restoring force for the magnet from the end position E to the start position S.

5 is a top view of the magnet 23 as he at the in 4A and 4B illustrated embodiment in the cylinder 20 is used. The magnet 23 is disc-shaped and has a diameter D _M , which is smaller than a diameter D _{Z of} the cylinder 30 is. To guide the magnet 23 and the weight increase is the magnet 23 with the guide element 36 Mistake. The guide element 36 is designed such that it has at least three points of contact 37 on the inner wall 29 of the cylinder 20 is applied. In the embodiment shown here, the guide element is located 36 with four points of contact 37 on the inner wall 29 of the cylinder 20 at. In the 5 The illustration shown should not be construed as limiting the invention. The number and distribution of touch points 37 of the guide element 36 with the inner wall 29 of the cylinder 20 is to be chosen such that a stable, smooth and sliding guidance of the magnet 23 is given in the cylinder. As already mentioned, the rigid rod acts 34 with a stop 35 together, hence the way of the magnet 23 in the axial direction A (see 4 ) is limited.

In 6 is the use of at least one control device according to the invention 1 for a pneumatic tool 2 at a plant 3 for the repair of paint damage to motor vehicles 5 shown. After painting a motor vehicle 5 Paint damage caused by dust or other particles can be detected. To eliminate this damage, these paint jobs with a polishing tool (pneumatic tool 2 ) in the designated facility 3 treated accordingly. For better recognition of the damaged paint spots is at least one lighting 90 intended. On a wall 18 the plant 3 is the at least one inventive control device 1 assembled. The control device 1 receives the for the operation of the pneumatic tool 2 (Polishing tool) required compressed air via a central supply 17 that with a central compressed air supply 19 connected is. As in 1 shown, is the pneumatic tool 2 from the controller 1 supplied with compressed air.

LIST OF REFERENCE NUMBERS

1

 control device

2

 pneumatic tool

3

 investment

4

 casing

5

 motor vehicle

6

 door

7

 Handle

8th

 management

9

 polishing

10

 Reset button

11

 supply

12

 derivation

13

 supply line

14

 pressure line

15

 diversion

16

 diversion

17

 central supply

18

 wall

19

 central compressed air supply

20

 cylinder

21

 outer wall

22

 magnetic valve

23

 magnet

24

 inflow

25

 outflow

26

 damping element

27

 limiting element

29

 inner wall

30

 first pneumatic valve

32

 feather

33

 feather

34

 pole

35

 attack

36

 guide element

37

 contact point

40

 second pneumatic valve

45

 third pneumatic valve

50

 Logic time valve

60

 time valve

70

 preset counter

80

 Reset valve

90

 lighting

A

 axial direction

D _M

 Diameter magnet

D _Z

 Diameter cylinder

e

 end position

S

 starting position

Claims (13)

Control device ( 1 ) for a pneumatic tool ( 2 ) with one in a supply line ( 13 ) provided for compressed air first pneumatic valve ( 30 ) and a time valve ( 60 ), which by means of the first pneumatic valve ( 30 ) the supply line ( 13 ) to the pneumatic tool ( 2 ): characterized by: a cylinder ( 20 ) with an inflow side ( 24 ) and an outflow side ( 25 ) for compressed air; • a magnet ( 23 ), which in the axial direction (A) between a start position (S) and an end position (E) movable in the cylinder ( 20 ) is arranged; and • a solenoid valve ( 22 ), which on an outer wall ( 21 ) of the cylinder ( 20 ) in the region of the end position (E) of the magnet ( 23 ), wherein the solenoid valve ( 22 ) a control signal to the time valve ( 60 ) when the magnet ( 23 ) in the end position (E), so that on the time valve ( 60 ) preset time interval is bootable. Control device ( 1 ) according to claim 1, wherein a damping element ( 26 ) between the inflow side ( 24 ) of the cylinder ( 20 ) and the magnet ( 23 ) is provided. Control device ( 1 ) according to claim 2, wherein a limiting element ( 27 ) between the magnet ( 23 ) and the outflow side ( 25 ) of the cylinder ( 20 ) is provided. Control device ( 1 ) according to claim 3, wherein the damping element ( 26 ) a feather ( 32 ) and the limiting element ( 27 ) a feather ( 33 ), both of which have a restoring force for the magnet ( 23 ) to the starting position (S). Control device ( 1 ) according to claim 3, wherein the damping element ( 26 ) is an elastic plastic component, which on the inflow side ( 24 ) is mounted, and wherein the limiting element ( 27 ) a feather ( 33 ), which at the same time a restoring force for the magnet ( 23 ) to the starting position (S). Control device ( 1 ) according to claim 5, wherein in addition to the spring ( 33 ) a rigid rod ( 34 ) with the magnet ( 23 ) connected to a stop ( 35 ) on the outflow side ( 25 ) of the cylinder ( 20 ) cooperates when the magnet ( 23 ) in the end position (E). Control device ( 1 ) according to claim 3, wherein the damping element ( 26 ) is an elastic plastic component, which on the inflow side ( 24 ) of the cylinder ( 20 ) is mounted, and wherein the limiting element ( 27 ) as a rigid rod ( 34 ) formed with a stop ( 35 ) on the outflow side ( 25 ) of the cylinder ( 20 ) cooperates when the magnet ( 23 ) in the end position (E). Control device ( 1 ) according to claim 7, wherein a guide element ( 36 ) with the magnet ( 23 ) connecting the rigid rod ( 34 ) and the guiding element ( 36 ) at least three points of contact ( 37 ) on an inner wall ( 29 ) of the cylinder is slidably guided. Control device ( 1 ) according to one of the preceding claims, wherein a second pneumatic valve ( 40 ) fluid with the time valve ( 60 ) and the first pneumatic valve ( 30 ), so that from the second pneumatic valve ( 40 ) a control signal of the time valve ( 60 ) can be received at the end of a preset time interval and the first pneumatic valve ( 30 ) by means of a control signal from the second pneumatic valve ( 40 ) the supply line ( 13 ) locks. Control device ( 1 ) according to claim 9, wherein a logic time valve ( 50 ) fluid with the first pneumatic valve ( 30 ) and the time valve ( 60 ), wherein a re-release of the flow of compressed air from a central compressed air supply ( 19 ) to the pneumatic tool ( 2 ) at the logic time valve ( 50 ) is adjustable via a switch-on delay. Control device ( 1 ) according to one of claims 9 to 10, wherein a pneumatically adding preselection counter ( 70 ) fluid via a third pneumatic valve ( 45 ) with the time valve ( 60 ), so that at a predefined number of cycles a shutdown of the pneumatic tool ( 2 ) he follows. Control device ( 1 ) according to claim 11, wherein a reset valve ( 80 ) fluid with the supply line ( 13 ) and at least with the preselection counter ( 70 ), whereby upon actuation of a reset button ( 10 ) the accumulated number of cycles on the preselection counter ( 70 ) is reset. Use of a control device ( 1 ) for a pneumatic tool ( 2 ) according to one of claims 1 to 12 in a plant ( 3 ) for repairing paint damage in a motor vehicle ( 5 ) after painting.

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