EP0478758B1 - Spray gun for applying foam, especially for filling hollow spaces in the automobile industry - Google Patents

Spray gun for applying foam, especially for filling hollow spaces in the automobile industry Download PDF

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Publication number
EP0478758B1
EP0478758B1 EP91908652A EP91908652A EP0478758B1 EP 0478758 B1 EP0478758 B1 EP 0478758B1 EP 91908652 A EP91908652 A EP 91908652A EP 91908652 A EP91908652 A EP 91908652A EP 0478758 B1 EP0478758 B1 EP 0478758B1
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EP
European Patent Office
Prior art keywords
foam
spray gun
metering chamber
gun according
sealing element
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP91908652A
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German (de)
French (fr)
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EP0478758A1 (en
Inventor
Mathias Pauls
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Rathor AG
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Rathor AG
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Publication date
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Publication of EP0478758A1 publication Critical patent/EP0478758A1/en
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D83/00—Containers or packages with special means for dispensing contents
    • B65D83/14—Containers or packages with special means for dispensing contents for delivery of liquid or semi-liquid contents by internal gaseous pressure, i.e. aerosol containers comprising propellant for a product delivered by a propellant
    • B65D83/28—Nozzles, nozzle fittings or accessories specially adapted therefor
    • B65D83/30—Nozzles, nozzle fittings or accessories specially adapted therefor for guiding the flow of spray, e.g. funnels, hoods
    • B65D83/303—Nozzles, nozzle fittings or accessories specially adapted therefor for guiding the flow of spray, e.g. funnels, hoods using extension tubes located in or at the outlet duct of the nozzle assembly
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
    • B05B1/30—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages
    • B05B1/3033—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages the control being effected by relative coaxial longitudinal movement of the controlling element and the spray head
    • B05B1/304—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages the control being effected by relative coaxial longitudinal movement of the controlling element and the spray head the controlling element being a lift valve
    • B05B1/3046—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages the control being effected by relative coaxial longitudinal movement of the controlling element and the spray head the controlling element being a lift valve the valve element, e.g. a needle, co-operating with a valve seat located downstream of the valve element and its actuating means, generally in the proximity of the outlet orifice
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B13/00—Machines or plants for applying liquids or other fluent materials to surfaces of objects or other work by spraying, not covered by groups B05B1/00 - B05B11/00
    • B05B13/06—Machines or plants for applying liquids or other fluent materials to surfaces of objects or other work by spraying, not covered by groups B05B1/00 - B05B11/00 specially designed for treating the inside of hollow bodies
    • B05B13/0627—Arrangements of nozzles or spray heads specially adapted for treating the inside of hollow bodies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D83/00—Containers or packages with special means for dispensing contents
    • B65D83/14—Containers or packages with special means for dispensing contents for delivery of liquid or semi-liquid contents by internal gaseous pressure, i.e. aerosol containers comprising propellant for a product delivered by a propellant
    • B65D83/16—Containers or packages with special means for dispensing contents for delivery of liquid or semi-liquid contents by internal gaseous pressure, i.e. aerosol containers comprising propellant for a product delivered by a propellant characterised by the actuating means
    • B65D83/20—Containers or packages with special means for dispensing contents for delivery of liquid or semi-liquid contents by internal gaseous pressure, i.e. aerosol containers comprising propellant for a product delivered by a propellant characterised by the actuating means operated by manual action, e.g. button-type actuator or actuator caps
    • B65D83/207—Actuators comprising a manually operated valve and being attachable to the aerosol container, e.g. downstream a valve fitted to the container; Actuators associated to container valves with valve seats located outside the aerosol container

Definitions

  • the invention relates to a spray gun for the metered application of foam, in particular for foaming cavities in the automotive industry, with an adapter part for a pressure container for blowing agent and foaming agent and an actuating lever for releasing the foam.
  • the invention relates in particular to a spray gun with which plastic foams, in particular one-component and two-component polyurethane foams, are applied from a pressure vessel at their place of use with the aid of a blowing agent.
  • the pressure container contains the foam components and the blowing agent, which is usually liquefied and correspondingly gasified when there is a sufficient pressure drop, as a result of which the foam-forming component is foamed.
  • the foam hardens more or less quickly when it comes into contact with a crosslinking agent, which is supplied by atmospheric moisture in the case of one-component foams and is added in the form of a second component in the case of two-component foams.
  • the pressure vessels are subject to safety standards, which on the one hand ensure the safe containment of the foam components and the blowing agent and on the other hand the safe connection via suitable adapters to commercially available foaming devices.
  • foams produced in this way are used as construction materials. They serve different purposes. When building, for example, frames can be sealed or cavities be sealed moisture-proof. Most foams of this type are therefore adjusted in such a way that they finally cure using the atmospheric humidity and require little time for this process.
  • a spray gun for the metered application of foam, in particular for foaming cavities in the automotive industry, with the features of the preamble of claim 1 is known from FR-A-2 351 713.
  • US-A-2 248 958 discloses a device for metering flowable substances, which has a metering chamber which is provided with a sealing element which is connected to an actuating member via a control element and which is provided with a closure element which is via the control element is operably connected synchronously to the sealing element.
  • Plastic foams especially polyurethane foams, are increasingly used in automotive engineering.
  • foaming of hollow parts to prevent corrosion.
  • Other areas of application are noise and thermal insulation and the protection of sensitive parts against mechanical injury.
  • noise protection measures there has recently been an increasing tendency to foam or foam into hollow profiles in order to dampen air vibrations.
  • Such hollow profiles are contained in many places in self-supporting vehicle bodies, as are used in modern automobile construction. They are created by folding and rolling the sheet metal parts where the body is to be given additional stiffening.
  • the design of the roof which is said to have roll resistance, is particularly problematic. It has been shown that the rear roof rail is particularly susceptible to air vibrations, the damping of which is desirable.
  • the foaming agent is supplied in the form of a prepolymer provided with blowing agent, which is under pressure.
  • blowing agent which is under pressure.
  • the amount of foam applied in the unit of time changes, which leads to a breakdown of the insulation effect when the critical amount is undershot.
  • all foaming agents used in conventional automotive technology tend to polymerize prematurely in the spraying or dosing device.
  • the time switching and switching mechanisms are changed to such an extent that the result is a slow decrease in the amount of foam over the operating life of the device. Cleaning these mechanisms is time-consuming and costly.
  • the object of the invention is therefore to provide a spraying device with which a reliable metering of foam for the foaming and foaming of cavities is possible.
  • This device is said to be particularly insensitive to premature polymerization of the foaming agent or one largely preclude such premature polymerization.
  • a spray gun of the type described at the outset which has a metering chamber for receiving a defined amount of foaming agent or foam which has not yet fully expanded, a sealing element which closes the metering chamber on the adapter side and is connected to the actuating lever via a control element, and a closure element which closes the spray gun on the mouthpiece side when the sealing element is open and is operably connected via the control element to the actuating lever in synchronism with the sealing element.
  • the invention also relates to the use of this spray gun for foaming or foaming hollow profiles.
  • the invention furthermore relates to a method for metering foam, in particular for dispensing metered amounts of foam for closing the ends of hollow profiles in automobile construction, in which a defined amount of a mixture of propellant and foaming agent is introduced into a metering chamber of predetermined volume and, if necessary, pre-expanded and the introduced and if necessary, the pre-expanded amount of foam is then released using the remaining driving force of the blowing agent and complete expansion.
  • the foaming agents used according to the invention are generally customary polyurethane prepolymers for one-component foams, which with the help a propellant can be applied from a pressure can. These prepolymers cure in a short time in the presence of water, which is usually provided by the moisture contained in the air.
  • conventional two-component polyurethane foams can also be used, in which the polyurethane prepolymer is brought together with an active hydrogen-containing hardener, generally a polyol, amino alcohol or polyamine, immediately before use and thus cures after a short time.
  • an active hydrogen-containing hardener generally a polyol, amino alcohol or polyamine
  • transitional forms from one-component to two-component foams in which an amount of hardener which is not sufficient for complete curing is used and the complete curing takes place via atmospheric moisture.
  • the spray guns can be handled on the one hand as homogeneous units that are used in different locations, but they can also be installed as automatic machines and thus used on production lines in series production. Although they are particularly suitable for the automotive industry, their application is not restricted to this area of application; they can be used in all areas where it is necessary to fill cavities or hollow profiles with a precisely metered amount of foam, such as. B. in mechanical engineering, and in construction as well as in refrigeration and air conditioning.
  • the mixture of foaming agent and blowing agent is first led out of the pressure bottle via an adapter into a dosing chamber of a defined volume.
  • This metering chamber is closed to the outside, so it fills up to the pressure equalization with the mixture of blowing agent and foaming agent, so that a pre-expansion may occur.
  • the opening through which the mixture is supplied is blocked and the metering chamber is opened to the outside, so that the possibly pre-expanded mixture can escape from the metering chamber into the object to be foamed or foamed under the residual pressure of the propellant contained therein.
  • the driving pressure in the pre-expanded mixture is so high that the dosing chamber is practically completely emptied.
  • the outlet opening is closed again and the feed opening for a new mixture of propellant gas and foaming agent is opened synchronously with it. In this way, a precisely defined amount of the mixture is pre-expanded in each cycle and taken to the location to be provided with foam.
  • the closure of the outlet opening largely prevents the entry of air humidity and thus the premature polymerization.
  • the pressure built up regularly inside and the expulsion of the pre-expanded mixture also have a corresponding effect.
  • Fig. 1 shows a conventional spray gun, such as for applying polyurethane foam from a Pressure bottle is used and the starting point for the invention.
  • An adapter (2) is located on a spray gun body (1), via which the pressure vessel (3) for the mixture of prepolymer and propellant gas is connected to the spray gun.
  • An operating lever (4) is used to operate the spray gun and an adjusting screw (5) is used to regulate the amount of foam or to secure the gun when not in use.
  • the foam produced is applied to the place of use via a spacer or discharge tube (6) through a mouthpiece (7).
  • Such a spray gun is described, for example, in German utility model G 83 04 005.6.
  • Fig. 2 shows the spray gun of Fig. 1 in a modified form according to the invention.
  • the metering chamber (8) is screwed onto the spray gun body (1) with the adapter part (2), the pressure vessel (3), the actuating lever (4) and the adjusting screw (5), on which in turn the spacer tube (6) with the mouthpiece (7).
  • the dosing chamber (8) has a cylindrical shape and a defined volume; it is sealed both to the spray gun body and to the outside by sealing elements which can be actuated synchronously.
  • the sealing elements are actuated synchronously by the actuating lever (4) via a control element, in the rest position the spray gun is closed to the outside and the metering chamber is open on the adapter side and when the lever (4) is actuated the metering chamber is closed and the mouthpiece (7) is released synchronously becomes.
  • Fig. 3 shows a section through the metering chamber and discharge tube of a spray gun according to the invention.
  • the metering chamber (8) in which the mixture of foaming agents, is connected to the spray gun body (1) and blowing agent is pre-expanded.
  • the dosing chamber (8) merges into the discharge or spacer tube (6), which ends in the mouthpiece (7) with the discharge nozzle (9).
  • the dosing chamber (8) is connected to the spray gun body (1) by a screw connection (16).
  • the tightness is ensured by a seal (18), for example an O-ring.
  • the dosing chamber (8) can be detached from the spray gun body (1) via the screw connection (16), for example for cleaning or maintenance or to replace it with a dosing chamber of a different volume.
  • the mouthpiece (7) is screwed into the discharge tube (6) so that it can be replaced.
  • a feed channel (11) for the blowing agent / prepolymer mixture which opens into the metering chamber (8), which in turn merges into the outflow channel (10) to the outlet opening.
  • a control element in the form of a control rod (13) which is connected in a conventional manner to the actuating lever (4).
  • the control element (13) is arranged concentrically in the chamber and in the channels. It ends in a closure element (14) which is seated in the nozzle cone (15) of the nozzle element (9).
  • a sealing element (12) is arranged concentrically around the control rod (13), which seals the feed channel (11) against the metering chamber (8) when the actuating lever (4) is actuated and the supply of Blowing agent / prepolymer mixture blocked.
  • This sealing element preferably consists of a piston or cone, which is located at the mouth edges of the channel (11). Further measures for sealing can be taken on the sealing element or its seat on the gun body (1), for example the arrangement of elastic sealing elements, etc. To improve the sealing effect, spring elements can be present which press the sealing element (12) against its seat in a sealing state .
  • Fig. 3 shows the closure element (14) and the sealing element (12) when the actuating lever (4) is relaxed.
  • the conical end of the closure element (14) seals the discharge channel (10) and the metering chamber (8) from the outside against the nozzle cone (15).
  • the sealing element (12) releases the metering chamber (8) against the feed channel (11).
  • the sealing element (12) closes the discharge chamber (8) against the feed channel (11), while the closure element (14) releases the opening of the nozzle (9), so that this in the chamber ( 8) Any pre-expanded mixture can escape.
  • closure element (14) at the outlet opening of the chamber (8) so that the discharge or spacer tube is open to the outside.
  • this enables the unhindered entry of air and air humidity into the outlet channel (10), which in turn leads to its slow polymerization, such an arrangement is not preferred.
  • Fig. 4 shows the section of FIG. 3 in a state in which the mouthpiece (7) of the closure element (14) is released and at the same time the feed channel (11) is separated from the chamber (8) by the sealing element (12). This is the case when the actuating lever (4) is actuated.
  • the blowing agent / prepolymer mixture flowing in from the pressure container (3) accumulates in the channel (11) in front of the sealing element (12), while at the same time the pre-expanded mixture located in the chamber under its residual pressure through the outlet channel (10 ) and the mouthpiece (7) flows out.
  • the dosing chamber (8) is partially integrated into the gun body (1); the screw connection (16) and the seal (18) connect a rear chamber part (19) to a front chamber part (20), which together form the dosing chamber (8).
  • the volume of the metering chamber (8) can be varied by appropriately enlarging or reducing the size of the front chamber part (20); in extreme cases, the volume of the metering chamber (8) can be drastically reduced by omitting the front chamber part (20) and forming a direct transition to the spacer tube (6).
  • Fig. 6 shows a third embodiment in which the discharge or spacer tube (6) is connected to the metering chamber (8) via a screw connection (17). This makes it easy to change the discharge tube.
  • control element (13) with the closure element (14) and the sealing element (12) can be regarded as a normal extension of the usual closure control of a spray gun. Accordingly, it is possible by constructive familiar to those skilled in the art Measures to modify a conventional spray gun, as shown in Fig. 1, by switching on a dosing chamber (8) and corresponding extension and equipment of the control rod according to the invention.
  • the spray gun according to the invention can be used with particular advantage for foaming the ends of hollow profiles in automobile construction.
  • the method according to the invention for foaming hollow profiles has proven to be particularly suitable for reliably foaming hollow profiles at the ends, so that effective damping of air vibrations is possible.

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  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Nozzles (AREA)
  • Filling Of Jars Or Cans And Processes For Cleaning And Sealing Jars (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Catching Or Destruction (AREA)
  • Medicinal Preparation (AREA)

Abstract

The invention concerns a spray gun for the metered application of foam, especially for filling hollow spaces in the automobile industry, with an adapter component (2) connectable to a pressure vessel (3) for propellants and foaming agents and an operating lever (4) for releasing the foam, which has a metering chamber (8) to take a determined quantity of not yet fully expanded foam, a sealing component (12) which closes off the metering chamber (8) on the adapter side and is connected to an operating lever (4) via a control component (13), and a closing device (14) which closes off the spray gun on the nozzle side when the sealing component (12) is open and is connected via the control device (13) to the operating lever (4) so as to be operable in synchronism with the sealing component (12).

Description

Die Erfindung betrifft eine Spritzpistole zum dosierten Ausbringen von Schaum, insbesondere zum Ausschäumen von Hohlräumen in der Automobilindustrie, mit einem Adapterteil für einen Druckbehälter für Treibmittel und Schaumbildner sowie einem Betätigungshebel zur Freigabe des Schaums.The invention relates to a spray gun for the metered application of foam, in particular for foaming cavities in the automotive industry, with an adapter part for a pressure container for blowing agent and foaming agent and an actuating lever for releasing the foam.

Die Erfindung betrifft insbesondere eine Spritzpistole, mit der Kunststoffschäume, insbesondere Einkomponenten- und Zweikomponenten-Polyurethanschäume, mit Hilfe eines Treibmittels aus einem Druckbehälter an ihrem Einsatzort ausgebracht werden. Der Druckbehälter enthält die Schaumstoffkomponenten und das Treibmittel, welches in der Regel verflüssigt ist und dementsprechend bei hinreichendem Druckabfall vergast, wodurch die schaumbildende Komponente aufgeschäumt wird. Der Schaum härtet bei Kontakt mit einem Vernetzungsmittel, das bei Einkomponentenschäumen von der Luftfeuchtigkeit geliefert wird und bei Zweikomponentenschäumen in Form einer zweiten Komponente unmittelbar vor der Schaumbildung zugesetzt wird, mehr oder weniger schnell aus. Die Druckbehälter unterliegen sicherheitstechnischen Normen, die zum einem den sicheren Einschluß der Schaumstoffkomponenten und des Treibmittels und zum anderen den sicheren Anschluß über geeignete Adapter an im Handel befindliche Schäumvorrichtungen gewährleisten.The invention relates in particular to a spray gun with which plastic foams, in particular one-component and two-component polyurethane foams, are applied from a pressure vessel at their place of use with the aid of a blowing agent. The pressure container contains the foam components and the blowing agent, which is usually liquefied and correspondingly gasified when there is a sufficient pressure drop, as a result of which the foam-forming component is foamed. The foam hardens more or less quickly when it comes into contact with a crosslinking agent, which is supplied by atmospheric moisture in the case of one-component foams and is added in the form of a second component in the case of two-component foams. The pressure vessels are subject to safety standards, which on the one hand ensure the safe containment of the foam components and the blowing agent and on the other hand the safe connection via suitable adapters to commercially available foaming devices.

Die auf diese Weise erzeugten Schäume werden als konstruktive Werkstoffe verwendet. Sie dienen unterschiedlichen Zwecken. Beim Bauen können damit zum Beispiel Zargen abgedichtet oder Hohlräume feuchtigkeitsdicht verschlossen werden. Die meisten Schäume dieser Art sind deswegen so eingestellt, daß sie unter Ausnutzung der Luftfeuchtigkeit endgültig aushärten und für diesen Vorgang nur wenig Zeit verbrauchen.The foams produced in this way are used as construction materials. They serve different purposes. When building, for example, frames can be sealed or cavities be sealed moisture-proof. Most foams of this type are therefore adjusted in such a way that they finally cure using the atmospheric humidity and require little time for this process.

Eine Spritzpistole zum dosierten Ausbringen von Schaum, insbesondere zum Ausschäumen von Hohlräumen in der Automobilindustrie, mit den Merkmalen des Oberbegriffs des Anspruchs 1 ist aus FR-A-2 351 713 bekannt.A spray gun for the metered application of foam, in particular for foaming cavities in the automotive industry, with the features of the preamble of claim 1 is known from FR-A-2 351 713.

US-A-2 248 958 offenbart eine Vorrichtung zur Dosierung von fließfähigen Substanzen, die eine Dosierkammer aufweist, welche mit einem Dichtelement versehen ist, das mit einem Betätigungsglied über ein Steuerelement verbunden ist, und die mit einem Verschlußelement versehen ist, das über das Steuerelement synchron zum Dichtelement betätigbar verbunden ist.US-A-2 248 958 discloses a device for metering flowable substances, which has a metering chamber which is provided with a sealing element which is connected to an actuating member via a control element and which is provided with a closure element which is via the control element is operably connected synchronously to the sealing element.

Kunststoffschäume, insbesondere Polyurethanschäume, finden zunehmend Anwendung im Automobilbau. Hier sei insbesondere auf die Ausschäumung von Hohlteilen zur Verhinderung von Korrosion verwiesen. Andere Anwendungsbereiche sind die Lärm- und Wärmedämmung sowie der Schutz empfindlicher Teile gegen mechanische Verletzung. Im Bereich der Lärmschutzmaßnahmen wird in jüngster Zeit zunehmend dazu übergegangen, Hohlprofile aus- bzw. zuzuschäumen, um Luftschwingungen zu dämpfen. Solche Hohlprofile sind in selbsttragenden Fahrzeugkarosserien, wie sie im modernen Automobilbau verwandt werden, an vielen Stellen enthalten. Sie entstehen durch Falten und Walzen der Blechteile dort, wo der Karosserie zusätzliche Versteifung verliehen werden soll. Besonders problematisch ist die Gestaltung des Daches, das eine Überrollsteifigkeit aufweisen soll. Es hat sich gezeigt, daß der hintere Dachholm besonders anfällig für Luftschwingungen ist, deren Dämpfung wünschenswert ist.Plastic foams, especially polyurethane foams, are increasingly used in automotive engineering. Here, particular reference is made to the foaming of hollow parts to prevent corrosion. Other areas of application are noise and thermal insulation and the protection of sensitive parts against mechanical injury. In the field of noise protection measures, there has recently been an increasing tendency to foam or foam into hollow profiles in order to dampen air vibrations. Such hollow profiles are contained in many places in self-supporting vehicle bodies, as are used in modern automobile construction. They are created by folding and rolling the sheet metal parts where the body is to be given additional stiffening. The design of the roof, which is said to have roll resistance, is particularly problematic. It has been shown that the rear roof rail is particularly susceptible to air vibrations, the damping of which is desirable.

Der einfachste Weg zur Dämpfung von Luftschwingungen in Hohlprofilen besteht darin, diese Hohlprofile entweder vollständig auszuschäumen oder aber an ihren Enden mit einer für diesen Zweck ausreichenden Schaummenge zuzuschäumen. Bereits durch das Zuschäumen der Enden wird der Luftaustausch mit der Umgebung wirksam unterbunden - was zugleich zu einem wirksamen Korrosionsschutz führt - und werden Luftschwingungen weitgehend eliminiert. Da das Zuschäumen an den Enden eine material- und gewichtsmäßige Einsparung mit sich bringt, ist es gegenüber dem vollständigen Ausschäumen bevorzugt.The simplest way to dampen air vibrations in hollow profiles is either to completely foam these hollow profiles or to foam them at their ends with a sufficient amount of foam for this purpose. Already by foaming the ends, the exchange of air with the environment is effectively prevented - which at the same time leads to effective corrosion protection - and air vibrations are largely eliminated. Since the foaming at the ends is a material and weight Saving, it is preferred over the full foaming.

Problematisch hierbei ist aber die genaue Dosierung des Schäumungsmittels. Während eine Überdosierung neben der Materialverschwendung keine negativen Folgen hat, führt eine Unterdosierung zu einer unzureichenden Schwingungsdämpfung und damit zu einem Nichteintreten der eigentlich beabsichtigten Wirkung. Unterdosierungen sind aber mit herkömmlichen Schäumungsverfahren kaum zu vermeiden, da die Dosierungsmechanismen nicht mit der nötigen Zuverlässigkeit arbeiten. Hierbei spielen vor allem zwei Effekte eine Rolle.The problem here is the exact dosage of the foaming agent. While an overdosing has no negative consequences in addition to the waste of material, an underdosing leads to insufficient vibration damping and thus to a failure to achieve the intended effect. Underdosing can hardly be avoided with conventional foaming processes because the dosing mechanisms do not work with the necessary reliability. Two effects play a role here.

Zum einen wird das Schäumungsmittel in Form eines mit Treibmittel versehenen Prepolymers geliefert, das unter Druck steht. Bei Unregelmäßigkeiten im Druck oder einer Abnahme des Treibgasdrucks im Vorratsbehälter ändert sich die in der Zeiteinheit ausgebrachte Schaummenge, was bei Unterschreiten der kritischen Menge einen Zusammenbruch der Dämmwirkung mit sich bringt. Zum anderen haben alle in der herkömmlichen Automobiltechnik verwandten Schaumbildner die Tendenz zur vorzeitigen Polymerisation bereits in der Spritz- bzw. Dosiereinrichtung. Hierdurch werden die Zeitschalt- und Umschaltmechanismen soweit verändert, daß eine langsame Abnahme der Schaummenge über die Betriebsdauer der Vorrichtung die Folge ist. Eine Reinigung dieser Mechanismen ist zeit- und kostenaufwendig.On the one hand, the foaming agent is supplied in the form of a prepolymer provided with blowing agent, which is under pressure. In the event of irregularities in the pressure or a decrease in the propellant gas pressure in the storage container, the amount of foam applied in the unit of time changes, which leads to a breakdown of the insulation effect when the critical amount is undershot. On the other hand, all foaming agents used in conventional automotive technology tend to polymerize prematurely in the spraying or dosing device. As a result, the time switching and switching mechanisms are changed to such an extent that the result is a slow decrease in the amount of foam over the operating life of the device. Cleaning these mechanisms is time-consuming and costly.

Aufgabe der Erfindung ist daher die Bereitstellung einer Spritzvorrichtung, mit der eine zuverlässige Dosierung von Schaum für das Aus- und Zuschäumen von Hohlräumen möglich ist. Dabei soll diese Vorrichtung insbesondere unempfindlich sein gegen vorzeitige Polymerisation des Schaumbildners bzw. eine solche vorzeitige Polymerisation weitgehend ausschließen.The object of the invention is therefore to provide a spraying device with which a reliable metering of foam for the foaming and foaming of cavities is possible. This device is said to be particularly insensitive to premature polymerization of the foaming agent or one largely preclude such premature polymerization.

Diese Aufgabe wird mit einer Spritzpistole der eingangs geschilderten Art gelöst, die durch eine Dosierkammer zur Aufnahme einer definierten Menge an Schaumbildner oder von noch nicht vollständig expandiertem Schaum, ein Dichtelement, das die Dosierkammer adapterseitig verschließt und mit dem Betätigungshebel über ein Steuerelement verbunden ist, sowie ein Verschlußelement, das die Spritzpistole bei geöffnetem Dichtelement mundstückseitig verschließt und über das Steuerelement mit dem Betätigungshebel synchron zum Dichtelement betätigbar verbunden ist, gekennzeichnet ist.This object is achieved with a spray gun of the type described at the outset, which has a metering chamber for receiving a defined amount of foaming agent or foam which has not yet fully expanded, a sealing element which closes the metering chamber on the adapter side and is connected to the actuating lever via a control element, and a closure element which closes the spray gun on the mouthpiece side when the sealing element is open and is operably connected via the control element to the actuating lever in synchronism with the sealing element.

Gegenstand der Erfindung ist ferner die Verwendung dieser Spritzpistole zum Ausschäumen bzw. Zuschäumen von Hohlprofilen.The invention also relates to the use of this spray gun for foaming or foaming hollow profiles.

Weiterhin ist Gegenstand der Erfindung ein Verfahren zum Dosieren von Schaum, insbesondere zum Ausbringen dosierter Schaummengen zum Verschließen der Enden von Hohlprofilen im Automobilbau, bei dem eine definierte Menge eines Gemisches aus Treibmittel und Schaumbildner in eine Dosierkammer vorgegebenen Volumens eingeführt und gegebenenfalls vorexpandiert und die eingeführte und gegebenfalls vorexpandierte Schaummenge anschließend unter Ausnutzung der verbliebenen Treibkraft des Treibmittels und vollständiger Expansion abgegeben wird.The invention furthermore relates to a method for metering foam, in particular for dispensing metered amounts of foam for closing the ends of hollow profiles in automobile construction, in which a defined amount of a mixture of propellant and foaming agent is introduced into a metering chamber of predetermined volume and, if necessary, pre-expanded and the introduced and if necessary, the pre-expanded amount of foam is then released using the remaining driving force of the blowing agent and complete expansion.

Bevorzugte Ausführungsformen und Arbeitsweisen sind Gegenstand der Unteransprüche.Preferred embodiments and modes of operation are the subject of the dependent claims.

Die erfindungsgemäß zum Einsatz kommenden Schaumbildner sind in der Regel übliche Polyurethan-Prepolymere für Einkomponentenschäume, die mit Hilfe eines Treibmittels aus einer Druckdose ausgebracht werden. Diese Prepolymere härten in Gegenwart von Wasser, das in der Regel durch die in der Luft enthaltene Feuchtigkeit bereitgestellt wird, in kurzer Zeit aus. Es können aber auch herkömmliche Polyurethan-Zweikomponentenschäume verwandt werden, bei denen unmittelbar vor der Anwendung das Polyurethan-Prepolymer mit einer aktiven Wasserstoff enthaltenen Verbindung Härter, in der Regel ein Polyol, Aminoalkohl oder Polyamin, zusammengebracht wird und damit nach kurzer Zeit aushärtet. Geeignet sind weiterhin Übergangsformen von Einkomponenten- zu Zweikomponentenschäumen bei denen eine zur vollständigen Aushärtung nicht ausreichende Menge Härter verwandt wird und die vollständige Aushärtung über die Luftfeuchtigkeit erfolgt.The foaming agents used according to the invention are generally customary polyurethane prepolymers for one-component foams, which with the help a propellant can be applied from a pressure can. These prepolymers cure in a short time in the presence of water, which is usually provided by the moisture contained in the air. However, conventional two-component polyurethane foams can also be used, in which the polyurethane prepolymer is brought together with an active hydrogen-containing hardener, generally a polyol, amino alcohol or polyamine, immediately before use and thus cures after a short time. Also suitable are transitional forms from one-component to two-component foams in which an amount of hardener which is not sufficient for complete curing is used and the complete curing takes place via atmospheric moisture.

Als Treibmittel für die oben genannten Zwei- und Einkomponentenschäume kommen herkömmliche voll- und teilhalogenierte Kohlenwasserstoffe in Frage, wie sie in der Schaumtechnik eingesetzt werden. Des weiteren können auch niedrig siedende Kohlenwasserstoffe bzw. Kohlenwasserstoffgemische eingesetzt werden, beispielsweise Propan und/oder Butan. Auch diese kohlenwasserstoffhaltigen Treibmittel sind dem Fachmann bekannt.Conventional fully and partially halogenated hydrocarbons, such as those used in foam technology, are suitable as blowing agents for the two-component and one-component foams mentioned above. Low-boiling hydrocarbons or hydrocarbon mixtures, for example propane and / or butane, can also be used. These hydrocarbon-containing blowing agents are also known to the person skilled in the art.

Erfindungsgemäß ist es möglich, zuverlässig dosierte Mengen in Hohlräume einzubringen und auf diese Weise beispielsweise Hohlträger im Automobilbau aus- bzw. zuzuschäumen. Die Spritzpistolen können einerseits als homogene Einheiten gehandhabt werden, die an verschiedenen Orten zum Einsatz kommen, sie können aber auch als Automaten installiert werden und so an Fertigungsstraßen in der Serienproduktion eingesetzt werden. Obwohl sie für den Automobilbau besonders geeignet sind, ist ihre Anwendung nicht auf dieses Einsatzgebiet beschränkt; sie können auf allen Gebieten verwandt werden, in denen es gilt, Hohlräume bzw. Hohlprofile mit einer genau dosierten Schaummenge aufzufüllen, so z. B. im Maschinenbau, und im Bauwesen sowie in der Kälte- und Klimatechnik.According to the invention, it is possible to introduce reliably metered quantities into cavities and in this way, for example, to foam or foam hollow beams in automobile construction. The spray guns can be handled on the one hand as homogeneous units that are used in different locations, but they can also be installed as automatic machines and thus used on production lines in series production. Although they are particularly suitable for the automotive industry, their application is not restricted to this area of application; they can be used in all areas where it is necessary to fill cavities or hollow profiles with a precisely metered amount of foam, such as. B. in mechanical engineering, and in construction as well as in refrigeration and air conditioning.

Erfindungsgemäß wird das Gemisch aus Schaumbildner und Treibmittel zunächst aus der Druckflasche über einen Adapter in eine Dosierkammer definierten Volumens geführt. Diese Dosierkammer ist nach außen hin abgeschlossen, füllt sich also bis zum Druckausgleich mit dem Gemisch aus Treibmittel und Schaumbildner, daß dabei gegebenenfalls eine Vorexpansion eingeht. Nach Abschluß des Füllvorganges wird die Öffnung, durch die das Gemisch zugeführt wird, blockiert und die Dosierkammer nach außen geöffnet, so daß das gegebenfalls vorexpandierte Gemisch unter dem Restdruck des darin enthaltenen Treibmittels aus der Dosierkammer in das zu- oder auszuschäumende Objekt austreten kann. Der Treibdruck im vorexpandierten Gemisch ist so hoch, daß die praktisch vollständige Entleerung der Dosierkammer gewährleistet ist. Nach deren Entleerung wird die Austrittsöffnung erneut verschlossen und synchron dazu die Zuführöffnung für neues Gemisch aus Treibgas und Schaumbildner freigegeben. Auf diese Weise wird in jedem Zyklus eine genau definierte Menge des Gemisches vorexpandiert und an den mit Schaum zu versehenden Ort geführt.According to the invention, the mixture of foaming agent and blowing agent is first led out of the pressure bottle via an adapter into a dosing chamber of a defined volume. This metering chamber is closed to the outside, so it fills up to the pressure equalization with the mixture of blowing agent and foaming agent, so that a pre-expansion may occur. After completion of the filling process, the opening through which the mixture is supplied is blocked and the metering chamber is opened to the outside, so that the possibly pre-expanded mixture can escape from the metering chamber into the object to be foamed or foamed under the residual pressure of the propellant contained therein. The driving pressure in the pre-expanded mixture is so high that the dosing chamber is practically completely emptied. After their emptying, the outlet opening is closed again and the feed opening for a new mixture of propellant gas and foaming agent is opened synchronously with it. In this way, a precisely defined amount of the mixture is pre-expanded in each cycle and taken to the location to be provided with foam.

Der Verschluß der Austrittsöffnung verhindert weitgehend den Zutritt von Luftfeuchtigkeit und damit die vorzeitige Polymerisation. Entsprechend wirkt auch der im Innern regelmäßig aufgebaute Druck und das Austreiben des vorexpandierten Gemisches.The closure of the outlet opening largely prevents the entry of air humidity and thus the premature polymerization. The pressure built up regularly inside and the expulsion of the pre-expanded mixture also have a corresponding effect.

Durch geeignete Wahl des Dosierkammervolumens ist es möglich, die jeweils freigegebe Schaummenge so zu dosieren, daß sie den Anforderungen entspricht.By suitable selection of the metering chamber volume, it is possible to meter the amount of foam released in such a way that it corresponds to the requirements.

Die zur Durchführung dieses Verfahrens geeignete erfindungsgemäße Spritzpistole wird nachstehend anhand der beigefügten Abbildungen, die bevorzugte Ausführungsformen darstellen, näher erläutert. Von diesen Abbildungen zeigen:

Fig. 1
Fig.1 eine herkömmliche Spritzpistole zum Ausbringen von Polyurethanschaum mit daran angebrachtem Druckbehälter;
Fig.2
eine erfindungsgemäße Spritzpistole mit aufgesetzter Dosierkammer;
Fig.3
einen Schnitt durch Austragsrohr und Dosierkammer der erfindungsgemäßen Spritzpistole gemäß Fig. 2 bei geöffneter Dosierkammer;
Fig.4
einen Schnitt durch Austragsrohr und Dosierkammer der erfindungsgemäßen Spritzpistole gemäß Fig. 2 bei geschlossener Dosierkammer und geöffnetem Austragsrohr;
Fig.5
einen Schnitt durch Austragsrohr und Dosierkammer einer weiteren Ausführungsform der erfindungsgemäßen Spritzpistole; und
Fig.6
eine dritte Ausführungsform der erfindungsgemäßen Spritzpistole.
The spray gun according to the invention which is suitable for carrying out this method is explained in more detail below with reference to the attached figures which represent preferred embodiments. From these pictures show:
Fig. 1
1 shows a conventional spray gun for dispensing polyurethane foam with a pressure vessel attached to it;
Fig. 2
a spray gun according to the invention with attached dosing chamber;
Fig. 3
a section through the discharge tube and metering chamber of the spray gun according to the invention shown in Figure 2 with the metering chamber open.
Fig. 4
a section through the discharge tube and metering chamber of the spray gun according to the invention shown in Figure 2 with the metering chamber closed and the discharge tube open.
Fig. 5
a section through the discharge tube and metering chamber of a further embodiment of the spray gun according to the invention; and
Fig. 6
a third embodiment of the spray gun according to the invention.

Fig. 1 zeigt eine herkömmliche Spritzpistole, wie sie zum Ausbringen von Polyurethanschaum aus einer Druckflasche eingesetzt wird und Ausgangspunkt für die Erfindung ist. Auf einem Spritzpistolenkörper (1) befindet sich ein Adapter (2), über den der Druckbehälter (3) für das Gemisch aus Prepolymer und Treibgas an die Spritzpistole angeschlossen wird. Ein Betätigungshebel (4) dient der Betätigung der Spritzpistole und eine Stellschraube (5) der Regulierung der Schaummenge bzw. der Sicherung der Pistole in unbenutztem Zustand. Der produzierte Schaum wird über ein Distanz- oder Austragsrohr (6) durch ein Mundstück (7) an den Verwendungsort ausgebracht. Eine solche Spritzpistole ist beispielsweise im deutschen Gebrauchsmuster G 83 04 005.6 beschrieben.Fig. 1 shows a conventional spray gun, such as for applying polyurethane foam from a Pressure bottle is used and the starting point for the invention. An adapter (2) is located on a spray gun body (1), via which the pressure vessel (3) for the mixture of prepolymer and propellant gas is connected to the spray gun. An operating lever (4) is used to operate the spray gun and an adjusting screw (5) is used to regulate the amount of foam or to secure the gun when not in use. The foam produced is applied to the place of use via a spacer or discharge tube (6) through a mouthpiece (7). Such a spray gun is described, for example, in German utility model G 83 04 005.6.

Fig. 2 zeigt die Spritzpistole von Fig. 1 in erfindungsgemäß abgewandelter Form. An den Spritzpistolenkörper (1) mit dem Adapterteil (2), dem Druckbehälter (3), dem Betätigungshebel (4) und der Stellschraube (5) ist die Dosierkammer (8) angeschraubt, an der sich wiederum das Distanzrohr (6) mit dem Mundstück (7) befindet. Die Dosierkammer (8) hat eine zylindrische Form und ein definiertes Volumen; sie ist durch Dichtelemente, die synchron betätigt werden können, sowohl zum Spritzpistolenkörper hin als auch nach außen hin abgedichtet. Die Dichtelemente werden durch den Betätigungshebel (4) über ein Steuerelement synchron betätigt, wobei in Ruhestellung die Spritzpistole nach außen hin geschlossen und die Dosierkammer adapterseitige geöffnet ist und bei Betätigung des Hebels (4) die Dosierkammer verschlossen und das Mundstück (7) synchron dazu freigegeben wird.Fig. 2 shows the spray gun of Fig. 1 in a modified form according to the invention. The metering chamber (8) is screwed onto the spray gun body (1) with the adapter part (2), the pressure vessel (3), the actuating lever (4) and the adjusting screw (5), on which in turn the spacer tube (6) with the mouthpiece (7). The dosing chamber (8) has a cylindrical shape and a defined volume; it is sealed both to the spray gun body and to the outside by sealing elements which can be actuated synchronously. The sealing elements are actuated synchronously by the actuating lever (4) via a control element, in the rest position the spray gun is closed to the outside and the metering chamber is open on the adapter side and when the lever (4) is actuated the metering chamber is closed and the mouthpiece (7) is released synchronously becomes.

Fig. 3 zeigt einen Schnitt durch Dosierkammer und Austragsrohr einer erfindungsgemäßen Spritzpistole. An den Spritzpistolenkörper (1) schließt sich die Dosierkammer (8) an, in der das Gemisch aus Schaumbildner und Treibmittel vorexpandiert wird. Die Dosierkammer (8) geht in das Austrags- oder Distanzrohr (6) über, das in dem Mundstück (7) mit der Austragsdüse (9) endet.Fig. 3 shows a section through the metering chamber and discharge tube of a spray gun according to the invention. The metering chamber (8), in which the mixture of foaming agents, is connected to the spray gun body (1) and blowing agent is pre-expanded. The dosing chamber (8) merges into the discharge or spacer tube (6), which ends in the mouthpiece (7) with the discharge nozzle (9).

Die Dosierkammer (8) ist über eine Schraubverbindung (16) mit dem Spritzpistolenkörper (1) verbunden. Die Dichtigkeit wird über eine Dichtung (18), beispielsweise einen O-Ring, sichergestellt. Über die Schraubverbindung (16) kann die Dosierkammer (8) vom Spritzpistolenkörper (1) gelöst werden, beispielsweise zur Reinigung oder Wartung oder um sie gegen eine Dosierkammer anderen Volumens auszutauschen. Wie die Dosierkammer (8) in den Pistolenkörper (1) ist auch das Mundstück (7) in das Austragsrohr (6) eingeschraubt, so daß es ausgetauscht werden kann.The dosing chamber (8) is connected to the spray gun body (1) by a screw connection (16). The tightness is ensured by a seal (18), for example an O-ring. The dosing chamber (8) can be detached from the spray gun body (1) via the screw connection (16), for example for cleaning or maintenance or to replace it with a dosing chamber of a different volume. Like the dosing chamber (8) in the gun body (1), the mouthpiece (7) is screwed into the discharge tube (6) so that it can be replaced.

Im Inneren des Spritzpistolenkörpers (1) verläuft ein Zuführkanal (11) für das Treibmittel/Prepolymer-Gemisch, der in die Dosierkammer (8) mündet, die ihrerseits wiederum in den Ausströmkanal (10) zur Austrittsöffnung übergeht. Im Inneren der Kanäle (10) und (11) und der Kammer (8) befindet sich ein Steuerelement in Form einer Steuerstange (13), das auf herkömmliche Weise mit dem Betätigungshebel (4) verbunden ist. Das Steuerelement (13) ist konzentrisch in der Kammer und in den Kanälen angeordnet. Es endet in einem Verschlußelement (14), das seinen Sitz in dem Düsenkonus (15) des Düsenelements (9) findet.In the interior of the spray gun body (1) runs a feed channel (11) for the blowing agent / prepolymer mixture, which opens into the metering chamber (8), which in turn merges into the outflow channel (10) to the outlet opening. Inside the channels (10) and (11) and the chamber (8) there is a control element in the form of a control rod (13) which is connected in a conventional manner to the actuating lever (4). The control element (13) is arranged concentrically in the chamber and in the channels. It ends in a closure element (14) which is seated in the nozzle cone (15) of the nozzle element (9).

Am adapter- oder ventilseitigen Ende der Dosierkammer (8) ist konzentrisch um die Steuerstange (13) ein Dichtelement (12) angeordnet, das bei Betätigung des Betätigungshebels (4) den Zuführkanal (11) gegen die Dosierkammer (8) abdichtet und die Zufuhr von Treibmittel/Prepolymer-Gemisch blockiert.At the adapter or valve end of the metering chamber (8) a sealing element (12) is arranged concentrically around the control rod (13), which seals the feed channel (11) against the metering chamber (8) when the actuating lever (4) is actuated and the supply of Blowing agent / prepolymer mixture blocked.

Dieses Dichtelement besteht vorzugsweise aus einem Kolben oder Kegel, der seinen Sitz an den Mündungskanten des Kanals (11) findet. Am Dichtelement oder seinen Sitz am Pistolenkörper (1) können weitere Maßnahmen zur Abdichtung getroffen werden, beispielsweise die Anordnung von elastischen Dichtelementen, usw.. Zur Verbesserung der Dichtwirkung können Federelemente vorhanden sein, die das Dichtelement (12) in dichtendem Zustand an seinen Sitz pressen.This sealing element preferably consists of a piston or cone, which is located at the mouth edges of the channel (11). Further measures for sealing can be taken on the sealing element or its seat on the gun body (1), for example the arrangement of elastic sealing elements, etc. To improve the sealing effect, spring elements can be present which press the sealing element (12) against its seat in a sealing state .

Fig. 3 zeigt das Verschlußelement (14) und das Dichtelement (12) bei entspanntem Betätigungshebel (4). In diesem Falle dichtet das Verschlußelement (14) mit seinem konischen Ende den Austragskanal (10) und die Dosierkammer (8) gegen den Düsenkonus (15) nach außen hin ab. Das Dichtelement (12) gibt in diesem Zustand die Dosierkammer (8) gegen den Zuführkanal (11) frei.Fig. 3 shows the closure element (14) and the sealing element (12) when the actuating lever (4) is relaxed. In this case, the conical end of the closure element (14) seals the discharge channel (10) and the metering chamber (8) from the outside against the nozzle cone (15). In this state, the sealing element (12) releases the metering chamber (8) against the feed channel (11).

Wird nun der Betätigungshebel (4) betätigt, so verschließt das Dichtelement (12) die Abzugskammer (8) gegen den Zuführkanal (11), während das Verschlußelement (14) die Öffnung der Düse (9) freigibt, so daß das in der Kammer (8) befindliche vorexpandierte Gemisch austreten kann.If the actuating lever (4) is now actuated, the sealing element (12) closes the discharge chamber (8) against the feed channel (11), while the closure element (14) releases the opening of the nozzle (9), so that this in the chamber ( 8) Any pre-expanded mixture can escape.

Natürlich ist es ebenfalls möglich, das Verschlußelement (14) an der Austrittsöffnung der Kammer (8) anzuordnen, so daß das Austrags- oder Distanzrohr nach außen hin offen ist. Da dies jedoch den ungehinderten Zutritt von Luft und Luftfeuchtigkeit in den Austrittskanal (10) ermöglicht, was wiederum zu seiner langsamen Zupolymerisation führt, ist eine solche Anordnung nicht bevorzugt.Of course, it is also possible to arrange the closure element (14) at the outlet opening of the chamber (8) so that the discharge or spacer tube is open to the outside. However, since this enables the unhindered entry of air and air humidity into the outlet channel (10), which in turn leads to its slow polymerization, such an arrangement is not preferred.

Fig. 4 zeigt den Schnitt gemäß Fig. 3 in einem Zustand, in dem das Mundstück (7) von dem Verschlußelement (14) freigegeben ist und zugleich der Zuführkanal (11) durch das Dichtelement (12) von der Kammer (8) getrennt ist. Dies ist bei Betätigung des Betätigungshebels (4) der Fall. In dem dargestellten Zustand staut sich das vom Druckbehälter (3) her anströmende Treibmittel/Prepolymer-Gemisch im Kanal (11) vor dem Dichtelement (12), während zu gleicher Zeit das in der Kammer befindliche vorexpandierte Gemisch unter seinem Restdruck durch den Austrittskanal (10) und das Mundstück (7) ausströmt.Fig. 4 shows the section of FIG. 3 in a state in which the mouthpiece (7) of the closure element (14) is released and at the same time the feed channel (11) is separated from the chamber (8) by the sealing element (12). This is the case when the actuating lever (4) is actuated. In the state shown, the blowing agent / prepolymer mixture flowing in from the pressure container (3) accumulates in the channel (11) in front of the sealing element (12), while at the same time the pre-expanded mixture located in the chamber under its residual pressure through the outlet channel (10 ) and the mouthpiece (7) flows out.

Fig. 5 zeigt einen Schnitt durch die Dosierkammer und das Austrittsrohr einer weiteren Ausführungsform der Erfindung. In dieser Ausführungsform ist die Dosierkammer (8) teilweise in den Pistolenkörper (1) integriert; die Schraubverbindung (16) und die Dichtung (18) verbinden einen hinteren Kammerteil (19) mit einem vorderen Kammerteil (20), die zusammen die Dosierkammer (8) bilden. Eine Variation des Volumens der Dosierkammer (8) kann durch eine entsprechende Vergrößerung oder Verkleinerung des vorderen Kammerteils (20) erfolgen; im Extremfall kann durch Fortlassen des vorderen Kammerteils (20) und Ausbilden eines direkten Übergangs zum Distanzrohr (6) das Volumen der Dosierkammer (8) drastisch verringert werden.5 shows a section through the metering chamber and the outlet pipe of a further embodiment of the invention. In this embodiment, the dosing chamber (8) is partially integrated into the gun body (1); the screw connection (16) and the seal (18) connect a rear chamber part (19) to a front chamber part (20), which together form the dosing chamber (8). The volume of the metering chamber (8) can be varied by appropriately enlarging or reducing the size of the front chamber part (20); in extreme cases, the volume of the metering chamber (8) can be drastically reduced by omitting the front chamber part (20) and forming a direct transition to the spacer tube (6).

Fig. 6 zeigt eine dritte Ausführungsform, in der das Austrags- oder Distanzrohr (6) über eine Schraubverbindung (17) mit der Dosierkammer (8) verbunden ist. Auf diese Art und Weise ist ein einfaches Wechseln des Austragsrohrs möglich.Fig. 6 shows a third embodiment in which the discharge or spacer tube (6) is connected to the metering chamber (8) via a screw connection (17). This makes it easy to change the discharge tube.

Das Steuerelement (13) mit dem Verschlußelement (14) und dem Dichtungselement (12) kann als normale Verlängerung der üblichen Verschlußsteuerung einer Spritzpistole angesehen werden. Entsprechend ist es möglich, durch dem Fachmann geläufige konstruktive Maßnahmen eine herkömmliche Spritzpistole, wie sie in Fig. 1 dargestellt ist, durch Einschalten einer Dosierkammer (8) und entsprechender Verlängerung und Ausrüstung der Steuerstange erfindungsgemäß abzuwandeln.The control element (13) with the closure element (14) and the sealing element (12) can be regarded as a normal extension of the usual closure control of a spray gun. Accordingly, it is possible by constructive familiar to those skilled in the art Measures to modify a conventional spray gun, as shown in Fig. 1, by switching on a dosing chamber (8) and corresponding extension and equipment of the control rod according to the invention.

Wie bereits dargestellt, kann die erfindungsgemäße Spritzpistole mit besonderem Vorteil zum Zuschäumen der Enden von Hohlprofilen im Automobilbau eingesetzt werden. Das erfindungsgemäße Verfahren zum Zuschäumen von Hohlprofilen hat sich als besonders geeignet erwiesen, Hohlprofile an den Enden zuverlässig zuzuschäumen, so daß eine wirksame Dämpfung von Luftschwingungen möglich ist.As already shown, the spray gun according to the invention can be used with particular advantage for foaming the ends of hollow profiles in automobile construction. The method according to the invention for foaming hollow profiles has proven to be particularly suitable for reliably foaming hollow profiles at the ends, so that effective damping of air vibrations is possible.

Claims (15)

  1. A spray gun for the metered delivery of foam, more particularly for foam-filling cavities in the motor vehicle industry, comprising an adapter (2) for connection to a pressure container (3) for a propellant and foam-former, and comprising an actuating lever (4) to release the foam, characterised by a metering chamber (8) to receive a defined quantity of foam-former or not yet completely expanded foam, a sealing element (12) which shuts off the metering chamber (8) on the adapter side and is connected to the actuating lever (4) via a control element (13), and a closure element (14) which, when the sealing element (12) is open, shuts off the spray gun on the nozzle side and is connected via the control element (13) to the actuating lever (4) so as to be adapted to actuation in synchronism with the sealing element (12).
  2. A spray gun according to claim 1, characterised in that the metering chamber (8) is disposed in the area of the transition from the gun body (1) to the spacer tube (6).
  3. A spray gun according to claim 1 or 2, characterised in that the control element (13) is a control rod extending axially in the tube (6) of the spray gun and in the metering chamber (8).
  4. A spray gun according to claim 3, characterised in that the sealing element (12) is disposed in the metering chamber (8) concentrically around the control rod (13) at the metering chamber opening on the valve side.
  5. A spray gun according to claim 4, characterised in that the sealing element (12) is a piston having a conical end or a cone with a seat on the tube (6) of the spray gun.
  6. A spray gun according to claim 5, characterised in that the sealing element (12) is a cone with an O-ring.
  7. A spray gun according to any one of claims 3 to 6, characterised in that the end of the control rod (13) simultaneously forms the closure element (14) for the nozzle (7), the cone (15) of the nozzle (7) serving as a seat.
  8. A spray gun according to any one of claims 2 to 7, characterised in that the metering chamber (8) and/or the spacer tube (6) is/are detachably connected to the spray gun body (1) via a connection (16, 17).
  9. A spray gun according to claim 8, characterised in that the connection is a screw or bayonet connection.
  10. A spray gun according to any one of claims 1 to 9, characterised in that the metering chamber (8) is variable in volume.
  11. A method of metering foam, more particularly for delivering metered quantities of foam for the purpose of closing the ends of hollow sections in motor vehicle construction, characterised in that a defined quantity of a mixture of propellant and foam-former is introduced into a metering chamber of preset volume and, if required, pre-expanded and the quantity of foam-former introduced or pre-expanded is then discharged by using the remaining propellent power of the propellant and complete expansion.
  12. A method according to claim 11, characterised in that on discharge of the foam that has been introduced and, if required, pre-expanded, the supply of propellant and foam former to the metering chamber is blocked.
  13. A method according to claim 11 or 12, characterised in that the metering chamber is shut off from the exterior during the introduction and pre-expansion phase.
  14. Use of the spray gun according to any one of claims 1 to 13 for the foam-filling or foam-closing of hollow sections.
  15. Use according to claim 14, for foam-closing hollow sections in motor vehicle construction, more particularly for the purpose of damping air vibrations.
EP91908652A 1990-04-21 1991-04-20 Spray gun for applying foam, especially for filling hollow spaces in the automobile industry Expired - Lifetime EP0478758B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE4012713 1990-04-21
DE4012713 1990-04-21
PCT/EP1991/000765 WO1991016139A1 (en) 1990-04-21 1991-04-20 Spray gun for applying foam, especially for filling hollow spaces in the automobile industry

Publications (2)

Publication Number Publication Date
EP0478758A1 EP0478758A1 (en) 1992-04-08
EP0478758B1 true EP0478758B1 (en) 1995-02-15

Family

ID=6404788

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91908652A Expired - Lifetime EP0478758B1 (en) 1990-04-21 1991-04-20 Spray gun for applying foam, especially for filling hollow spaces in the automobile industry

Country Status (6)

Country Link
EP (1) EP0478758B1 (en)
AT (1) ATE118377T1 (en)
DE (1) DE59104588D1 (en)
ES (1) ES2068582T3 (en)
WO (1) WO1991016139A1 (en)
ZA (1) ZA912934B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102016122886A1 (en) * 2016-11-28 2018-05-30 Richard Fritz Holding Gmbh Disc unit for closing an opening, method for producing a stiffening element for a disc unit and method for producing a disc unit and apparatus for producing such a disc unit

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2676940B1 (en) * 1992-05-25 1993-12-17 Etudes Realisations Tech Meca PISTON GUN FOR INJECTION OF A SELF-EXPANDING MOUSE.
DE9208262U1 (en) * 1992-06-25 1992-08-13 Arno Lindner KG, 8000 München Spray valve for vacuum wax injection system
ES1062243Y (en) * 2006-03-15 2006-08-16 Diez Ana Belen Garcia SPRAY GUN, PARTICULARLY TO APPLY VERY VISCOSE FLUIDS AT A GREAT DISTANCE
CZ306629B6 (en) 2016-02-19 2017-04-05 Jaroslav Misler A nozzle of a gun for application of polyurethane foam through a flexible attachment and a gun with such a nozzle
DE202016103159U1 (en) 2016-06-15 2016-06-24 IN-INN s.r.o. Connection element for fixing a flexible extension to a spray gun for application of polyurethane foam in hard to reach places and spray gun for attachment of a flexible extension
CZ307310B6 (en) * 2017-03-24 2018-05-23 IN-INN s.r.o. A gun nozzle for attaching a flexible extension for application of polyurethane foam to hardly accessible areas and a gun with this nozzle

Family Cites Families (4)

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Publication number Priority date Publication date Assignee Title
US3128915A (en) * 1964-04-14 matter
US2248958A (en) * 1938-04-14 1941-07-15 Carl J Christensen Dispensing device
US3878973A (en) * 1973-10-31 1975-04-22 Ciba Geigy Corp Metered dose dispenser
SE422282B (en) * 1975-12-18 1982-03-01 Atlas Copco Ab SPRAY GUN

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102016122886A1 (en) * 2016-11-28 2018-05-30 Richard Fritz Holding Gmbh Disc unit for closing an opening, method for producing a stiffening element for a disc unit and method for producing a disc unit and apparatus for producing such a disc unit

Also Published As

Publication number Publication date
ES2068582T3 (en) 1995-04-16
DE59104588D1 (en) 1995-03-23
WO1991016139A1 (en) 1991-10-31
ATE118377T1 (en) 1995-03-15
ZA912934B (en) 1992-03-25
EP0478758A1 (en) 1992-04-08

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