DE60313614T2 - DEVICE FOR APPLYING LIQUIDS - Google Patents

Abstract

The invention relates to a device for the application of a fluid. The device is intended to be mounted as a tool on a holder which is adjustable between different positions and directions. The device comprises preferably at least two nozzles (12) for discharge of said fluid, one product valve means (4) associated with each nozzle for control of the supply of fluid to each nozzle, a swivel means (2) which connects the holder to a rotatable nozzle head carrying said nozzles. Two channels are preferably arranged through said swivel means (2) for establishing fluid communication between the holder and the rotatable nozzle head. According to the invention the product valve means (4) are arranged in the rotatable nozzle head. This means that channels in the swivel (2) may be used for inlet and return channels enabling circulation up to the product valves (4) located close to the nozzles (12). The feature also allows the channels in the swivel to be used for separate fluids enabling mixing at the nozzle head for two-component application of fluids or enabling application of two different fluid materials.

Description

FIELD OF THE INVENTION

The The present invention relates to a device for applying a fluid.

BACKGROUND OF THE INVENTION

A current Apparatus for applying a fluid is used in practice as a rotatable spray gun executed which has a number of spray nozzles and so executed is that it is mounted on a robot control device.

spray guns are used when fluids such as gases, liquids or plastic materials on a surface sprayed or to be extruded. An example in the field of application such a spray gun exists in the automotive industry when bodywork is surface treated or joints to be sealed. Other areas of Application are natural also possible.

STATE OF THE ART

A device for applying fluid is known from the publication WO 97/02 901, which discloses features of the preamble of claim 1. The principle is in 1 shown. The old pistol had a swivel head 2 ' consisting of three different material channels between the product valves 4 ' and the nozzles. The three valves were fed by a common inlet channel. The valves 4 ' were by adjusting elements 20 ' opened, which are placed on a pneumatic valve block on the robot arm. All this led to slow reaction times between the actuators 20 ' and the valves 4 ' and at far distances of z. B. 20-30 centimeters between the valves 4 ' and the nozzles. A circulation was only possible up to the common product intake. The fact that the material behind the different valves 4 ' When swirling, the nozzle swirled between the seals and the feed ring in the swivel head 2 ' , This pulsing many times resulted in drops of material spilling out of the other nozzles when a valve was opened.

The The present invention seeks to solve the above-mentioned problems. One Main feature is that the product valve device in the rotatable nozzle head close to the jets is arranged. The distance between the valves and the nozzles can be reduced to 10-50 mm. This means that the channels in the swivel head used as inlet and return channels can be which allow circulation up to the product valves close to the nozzles are located. The feature also makes it possible for the channels in the swivel head for separate Fluids are used, with an application of different Fluids or mixing at the nozzle head for one Two-component application of fluids is possible. Accordingly In one embodiment of the Invention, the gun on a swivel head, which consists of a material inlet channel and a return channel which leads to the product valves which are the outermost End of the nozzle lance lie. The valves are controlled by solenoid controlled actuators open, which are also placed on the rotating part of the gun. this leads to to very fast reaction times between the solenoid coils, actuators and valves, since they are mounted close to each other. The distance is kept to a minimum between the product valves and the nozzles. This solution makes it possible for that the material circulates almost all the way to the nozzles, which is a minimum Need for rinsing brings with it. The control elements are driven by compressed air, which is fed by the swivel head in a channel, wherein the electrical signals are passed through a slip ring device. By keeping the valves close to the nozzles, snuffback (suck-back) Effects more effective, being a drop due to the pulsation is avoided.

SUMMARY OF THE INVENTION

The The present invention provides a device for applying Fluid ready for attachment as a tool to a holder is determined, between different positions and directions can be adjusted. The device comprises at least two nozzles for expel of the fluid, a product valve device associated with each nozzle, around the Supply of fluid to each nozzle to control, and a pivoting device, which is a holder with a rotatable nozzle head connects the nozzles wearing. At least one channel, preferably at least two channels through the pivoting device and in the rotatable part arranged to fluid communication between the holder and the rotatable nozzle head manufacture. The channels have the ability to rotate freely relative to the holder.

According to the invention Product valve device arranged in the rotatable nozzle head.

at an embodiment a channel in the swivel head is an inlet channel for supplying Fluid to the nozzle head, wherein another channel in the swivel head has a return channel for returning Fluid from the nozzle head is.

In a further embodiment is a first channel in the swivel head, an inlet channel for a first fluid to the nozzle head, wherein a second channel in the swivel head is an inlet channel for a second fluid to the nozzle head.

Preferably is a pneumatic channel through the pivoting device arranged to provide a pneumatic connection between the holder and the rotatable nozzle head manufacture, wherein the product valve device by a pneumatic Control operated becomes.

In addition, electrical Lines be arranged through the pivoting device, to an electrical connection between the holder and the rotatable nozzle head manufacture, wherein electrical valve actuators, fitting Magnetic coils, in the nozzle head are arranged to the pneumatic actuation of the product valve device to control.

The The invention is defined in claim 1, while preferred embodiments in the dependent claims are set out.

BRIEF DESCRIPTION OF THE DRAWINGS

The The invention will become more apparent in the following detailed description described making reference to the accompanying drawings becomes, in which show:

1 a schematic view illustrating the principles of a robot gun according to the prior art;

2 a schematic view illustrating the principles of a robot gun according to an embodiment of the present invention;

3 a schematic view illustrating the principles of a robot gun according to another embodiment of the present invention;

4 a perspective view of an embodiment of the present invention, which is attached to a holder,

5 a cross-sectional view of the base module of an embodiment of the present invention;

6 an exploded view of the valve actuators;

7A a perspective view of a first nozzle configuration;

7B a perspective view of a second nozzle configuration;

7C a perspective view of a third nozzle configuration;

8A and 8B Cross-sectional views of the snuffback (suction) valve in a closed or open position; and

9A and 9B Perspective views of the needle in a high precision configuration and the needle in a high flow configuration.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The principles of the device according to the invention are in 2 shown. The device comprises a non-rotating part or adapter 1 which is to be connected to a holder on a robot arm and a rotating part which carries nozzles for applying a fluid. A swivel device 2 provides rotatable connections for air, fluid and electrical signals. Close to the nozzles 12 There are product valves in the rotating nozzle head 4 , The product valves 4 are pneumatic valves driven by air and by valve actuators 20 be controlled, in turn, of electrical signals by electrical control elements, for. B. magnetic coils 19 to be controlled. The fluid to be applied by the nozzles circulates through the swivel head 2 and right up to the product valves 4 ,

As with the non-schematic drawings, see, for. B. 4 As will be apparent, the device for applying a fluid is designed as a pistol-shaped tool having five main components, namely an adapter 1 which serves to connect the gun with a robot arm, a pivoting device 2 , which can transmit a rotary motion, a connection 3 to a feed device for a fluid such as a gas, a liquid or a plastic material, a positioning lance 5 and a head 6 with a number of spray or extrusion nozzles 12 , The structure and the respective function of these different main components will be described below.

The adapter 1 is designed to be mounted on a robotic arm of any known type, either directly or by means of an intermediate adapter. A robotic arm can typically perform movements in six degrees of freedom, that is, movements in three directions, rotation about first and second axes that are orthogonal to each other and that are at right angles to the longitudinal direction of the robotic arm, and rotation about a third axis that are in the longitudinal direction tion of the robot arm extends. The adapter 1 transmits the rotational movement about this longitudinal axis either because the adapter is rigidly rotated or because a shaft disposed in the adapter is rotated with respect to the adapter. The arranged in the adapter shaft is provided with a shaft 8th ( 5 ) connected in the pivoting device 2 is held rotatably. This shaft can be an integral continuation of the adapter shaft.

Regarding 5 is the pivoting device 2 to the outside through a housing 10 limited, which has an outer surface 11 and an inner cylindrical wall and two end faces. The lateral surface of the housing is substantially cylindrical, but of course other shapes of the lateral surface of the housing are also possible. The gun can basically be mounted on any type of robot. It is only a matter of matching the mechanical adapter and the swivel head locking device.

The spray gun in the simplest form has one and, in the example shown in the drawing, three spray or extrusion nozzles 12 (see also 7A . 7B and 7C ). To ensure the functioning of the gun, each of the nozzles has a channel between the product valve and the nozzle. As a result, each nozzle can be opened and closed independently of the others. For this reason, it is possible to open one or more nozzles at the same time.

7A and 7B show nozzle configurations with three nozzles 12 pointing in different directions. In 7A has a nozzle straight forward, with a second nozzle facing to one side at a right angle and a third nozzle at an angle of 45 ° in the front direction at a right angle to the plane formed by the first two nozzles. In 7B all nozzles are at an angle of 45 ° in the front direction and are spaced symmetrically about 120 ° around the circumference. The nozzle configurations are selected based on their intended application. The nozzles are preferably used singly with the same or (two) different materials.

7C shows a nozzle configuration with three nozzles 12 pointing in the same direction. The nozzles can be used simultaneously with the same material to form wider material drops or arcs. Since the product valves can be individually controlled, it is possible to activate one to three of the nozzles as a way to select the width of the drops.

5 is a cross-sectional view through the base module. The gun has swivel functions for electrical signals, compressed air and the product. The media penetrate the gun through holes 13 and 14 in the housing (or exit, depending on the application) and become the rotation shaft 8th forwarded. In the shaft channels for air, material and the electrical cables to the solenoid valves are made. The shaft with the channels may be relative to the adapter 1 and the holder with unobstructed connection through the channels for electrical signals, compressed air and the product are freely rotated.

The swivel head is also equipped with an electric slip ring device 15 fitted. The slip ring device was placed next to the coupling in the back of the module. The cables to the solenoid valves run in a hole drilled through the shaft. The cables equipped with a contact for the solenoid valves may be soldered to the shaft portion of the slip ring device.

The hole 7 in 5 is the inlet for compressed air to the valves. The pneumatic delivery hose is connected with a standard threaded quick connection. The same air supply is preferably used to drive all the pneumatic valve actuators. The holes 13 and 14 are inlets / outlets for the fluid material to be applied. The design allows the inlet and the return of a material for the circulation or the inlet of two different materials in the non-rotating part. This makes it possible to adapt the gun to use two different materials and two-component materials. As will be appreciated, it is possible to design the device with multiple fluid material inlets / outlets.

A inventive device can be equipped with two different types of product valves be, a high flow type and a type based on the so-called snuffback valve. In this application, the snuffback type becomes a high-precision configuration designated.

The product valves 4 be through valve actuators 20 actuated. The arrangement of the valve actuators is in 6 shown. To open the product valves in the gun, each valve is connected by a rod 21 maneuvered with an air-operated piston 22 connected is. The admission of compressed air into the cylinder 23 moves this piston 22 in his turn. This air inlet is activated by a solenoid valve, one for each valve, and reduced in pressure. The same parts are mainly used for both the high-precision and high-flow configurations. One difference is that the rods go backwards to open the valves in the high-flow gun NEN, and moved forward to do the same in the high-precision version. Modifying an adapter plate for the solenoid valves produces this difference.

As solenoid valves conventional valves can be used, which should preferably be fast and very small. The valves are controlled by DC signals which are passed through the electrical slip ring device. The air connection from the solenoid valves to the gun can be through a plastic air block 18 ( 4 ), which is manufactured by laser-sintering. This will reduce the dimensions of the middle section of the gun. By forming different channels in this air block, the actuators are configured for the high flow or high precision configuration. The sintering manufacturing process offers great freedom in the design of the air channels through the block 18 ,

According to 6 For example, a design with three pneumatic cylinders arranged longitudinally one behind the other, angularly spaced 120 degrees apart, was made to obtain a small diameter of the gun in a minimum of space and weight. The actuators are supplied with compressed air for the back and forth movement of the solenoid coils. In the high flow configuration, a spring is mounted in the actuator cylinder (not shown) to close the product valve in the event of a lost supply of compressed air or a malfunction in the solenoid.

As earlier mentioned was focused on the high-precision configuration on sharp start and stop and constant drop widths. The High precision configuration allowed no such high flow of material like the high-flow gun. Execution of the high-precision nozzle head is made so that a snuffback or suck back is possible and given as clear starting and stopping of the drops as possible is. Suitable applications are sealing and other drop applications, where the cosmetic or visual appearance of great importance is. The high-precision configuration is usually used together with slot nozzles.

The function of the high-precision valve is in 8A and 8B illustrates where 8A the closed position and 8B show the open position. When the needle is in its rear position, there is a gap between the needle 24A and the ball 25 , where the ball 25 the valve seat 26A closes (see 8A ). The valves in the high-precision nozzle head are opened by pulling the piston rod towards the ball 25 meets, with the ball 25 from the seat 26A after being pressed. The philosophy is that the needle 24A should gain in speed before getting the ball 25 reached, and then hits the ball at an almost instantaneous opening from the closed to the fully open valve, as a result, a full flow is achieved. However, this distance increases the response time from the transmitted signal until the valve is open.

When the needle is in the position according to 8A is withdrawn, it creates a snuff-back force for the material in the nozzle channel. This function has been used with prior art product valves and has been useful when the valve was in front of the nozzle with different lance lengths in front of the swivel head. The ball 25 is by a return spring 27 pressed to the valve seat to close the flow.

The high-flow type of valve is in 5 shown. The design of the valve with the high-flow configuration is made so that a maximum flow of material is made possible. A needle 24B opens the valve as it passes through the actuator from the seat 26B is pulled back. The design does not contain a ball to close the valve, but the needle 24B closes directly at the valve seat 26B , The design provides high flow rates, but no snuffback is achieved when the piston moves forward to close the valve. In 5 the valve is shown in the closed position.

The lance 5 (eg 5 ) is used to get different pistol lengths. This is a parameter that you might want to change depending on the workspace and the position of the robot. The design was made with a stainless steel tube made in different lengths with aluminum flanges on both ends. Within the lance, the fluid material tubes and the piston rods for the valves are arranged.

By Placing a nozzle head with high flow configuration on the gun it is possible Supply materials with very high flows of material. The flow rates are of the material and the nozzle type dependent, but it is no problem to reach flows of over 100 ml / s. Suitable applications are vibration damping, underbody coating and other coating applications normally characterized by Extrusion or spray extrusion nozzles applied become.

The details for the piston rods 21 are common between the high precision and high flow configurations except for the needles. The high precision configuration uses a similar design to those used in the product valve for the prior art device. As in 9A and 9B is shown has the needle 24A for the high-precision configuration, a flat front end that hits the ball 25 is suitable while the needle 24B for the high flow configuration, has a rounded forward end that closes the valve by pushing against the valve seat 26B encounters.

The High precision and the high flow configurations differ only in a few parts of the nozzle head, it's easy to move a gun from one configuration to another to modify. The high-flow configuration was mainly for high-flow applications provided, but tests have shown that this configuration also for Gasket applications gives excellent results.

The device according to the invention can be adapted for an application with 2-component material. 3 shows the principle. Most of the components of the gun are the same as for a conventional 1-component gun. However, the gun needs to be adjusted to allow a mixer 9 , z. B. a static mixer, can be mounted in the front part. The base module (non-rotating part) of the gun is prepared so that it can supply two different materials. The two materials will be able to circulate separately in the base module as it is possible to attach two inlet and two outlet tubes to the gun. There is no circulation in the rotating part. In the rotating part are two of the valve actuators 20A and 20B each of the two material channels to the mixer 9 open with a common outlet for the mixed components. If necessary, can be a separate valve 4C be provided at the common outlet, wherein a third valve actuator 20C could be used to control the flow of mixed material to the nozzle 12C to open.

In another embodiment, the product valves open 4A and 4B each directly to a separate nozzle, allowing the use of two different fluid materials.

at the gun according to the invention The material can circulate almost the entire distance to the nozzles. This ensures a good control of the material temperature and viscosity, wherein the need for Rinsing very limited will be. If two different materials for different Nozzles of the Gun or when a 2-component material is used, it will still be possible be that both materials circulate in the gun. In these Cases the circulation is limited to the basic module of the pistol.

The circulation is through an external circulation valve 28 controlled ( 2 ), which opens the return hose. As an alternative, the circulation valve can be integrated with the gun, e.g. B. be arranged together with the product valves. If available, even one of the product valves could be used. There is a check valve between the hose and the gun 29 installed to eliminate the negative effect of accumulated pressure in the return hose.

The Gun can be equipped with two different temperature sensors its one to measure the product temperature and the other to the Temperature of the heated housing to measure the gun. Heating elements and temperature sensors can be used in the casing be integrated with the device. Material sensors can be used in be integrated with the connecting plate, where the material pipes with the housing are connected.

Even though the invention described herein with reference to particular embodiments was, should understand be that these embodiments only the principles and illustrate applications of the present invention. It should therefore understand be that numerous modifications to the illustrated embodiments made and that further arrangements can be devised, without to depart from the scope of the present invention, as characterized by the attached claims is defined.

Claims (21)

Device for applying fluid intended for mounting as a tool on a holder, which can be adjusted between different positions and directions, the device comprising at least two nozzles ( 12 ) for discharging the fluid, a product valve device ( 4 ) to each nozzle ( 12 ) to control the supply of fluid to each nozzle, and a pivoting device ( 12 ) comprising a holder ( 1 ) with a rotatable part with a nozzle head ( 6 ) connecting the nozzles ( 12 ), wherein at least one fluid channel through the pivoting device ( 12 ) and in the rotatable part is arranged to fluid connection between the holder ( 1 ) and the rotatable nozzle head ( 6 ) and the channel has the ability to move relative to the holder ( 1 ), characterized in that the product valve means ( 4 ) in the rotatable nozzle head ( 6 ) are arranged. Apparatus according to claim 1, characterized in that two fluid channels through the pivoting device ( 2 ) are arranged through, wherein a channel in the pivoting device ( 2 ) an inlet channel for supplying fluid to the nozzle head ( 6 ) and another channel in the pivoting device ( 2 ) a return channel for returning fluid from the nozzle head ( 6 ). Apparatus according to claim 1, characterized in that the fluid channels to at least one Produktventileinrchtung ( 4 ), which are used to eject the fluids via a corresponding nozzle ( 12 ) can be controlled. Device according to one of the preceding claims, characterized in that the fluid is arranged to be connected to the product valves ( 4 ) circulating through a circulation valve ( 28 ) arranged to open a return hose. Apparatus according to claim 4, characterized in that a check valve ( 29 ) is installed between the return hose and the holder. Apparatus according to claim 1, characterized in that two fluid channels through the pivoting device ( 2 A first fluid channel in the pivot means is an inlet channel for a first fluid to the nozzle head and a second fluid channel in the pivot means is an inlet channel for a second fluid to the nozzle head. Apparatus according to claim 6, characterized in that the first and the second fluid channel to a first and a second product valve device ( 4A . 4B ) for ejecting the first and second fluids into a mixing chamber ( 9 ) can be controlled to eject mixed fluids through a common nozzle. Apparatus according to claim 7, characterized in that the mixing chamber ( 9 ) to a third product valve device ( 4C ), which can be controlled to eject the mixed fluids through the common nozzle. Device according to one of the preceding claims, characterized in that the distance between the product valve devices ( 4 ) and the nozzle ( 12 ) is in the range of 10-50 mm. Device according to one of the preceding claims, characterized in that a compressed air channel through the pivoting device ( 2 ) is arranged therethrough to compressed air connection between the holder and the rotatable nozzle head ( 6 ) and that the product valve devices ( 4 ) are operated by compressed air control. Apparatus according to claim 10, characterized in that one and the same compressed air channel for driving all product valve devices ( 4 ) is used. Apparatus according to claim 10 or 11, characterized in that the compressed air connection from the pivoting device ( 2 ) to the rotatable nozzle head ( 6 ) via a plastic air block ( 18 ) produced by a laser sintering method. Apparatus according to claim 10, 11 or 12, characterized in that electrical lines through the pivoting device ( 2 ) are arranged therethrough for electrical connection between the holder and the rotatable nozzle head ( 6 ) and that electrical valve actuators ( 19 ) in the nozzle head ( 6 ) are arranged to control the pneumatic actuation of the product valve devices ( 4 ) to control. Apparatus according to claim 13, characterized in that the pivoting device ( 2 ) with an electrical slip ring device ( 15 ) is provided. Apparatus according to claim 13 or 14, characterized in that the electric valve actuators electromagnet ( 19 ) are. Device according to one of the preceding claims, characterized in that a valve actuator ( 20 ) with each product valve ( 4 ), the valve actuator being a rod ( 21 ) equipped with an air-controlled piston ( 22 ) connected in a cylinder ( 23 ) is arranged, wherein the cylinder ( 23 ) has an air inlet that is activated by a solenoid valve for each product valve and depressurized, and that the valve actuator ( 20 ) is located in the rotatable part. Apparatus according to claim 16, characterized in that the air cylinder ( 23 ) of various valve actuators ( 20 ) are arranged one behind the other in the longitudinal direction and angularly spaced apart by 120 degrees. Device according to one of claims 1 to 17, characterized in that the product valve is a needle ( 24A ), a ball ( 25 ) and a valve seat ( 26A ), wherein a distance between the needle ( 24A ) and the ball ( 25 ) is present when the product valve is in its closed position, and the ball ( 25 ) the valve seat ( 26A ) and the product valve is arranged to be opened by the piston rod ( 21 ) after being pulled on the ball ( 25 ) and the ball ( 25 ) from the seat ( 26A ) after presses. Device according to claim 18, characterized in that the needle ( 24A ) a flat front end for hitting the ball ( 25 ) Has. Device according to one of claims 1 to 17, characterized in that the product valve is a needle ( 24B ) and a valve seat ( 26B ), wherein the needle ( 24B ) is arranged so that it directly on the valve seat ( 26B ) and the needle ( 24B ) is arranged to open the valve as it passes through the actuator from the seat (10). 26 ) is pulled backwards. Device according to claim 20, characterized in that the needle ( 24B ) has a rounded front end for sealing to the valve seat ( 26B ) Has.