EP0137861B1 - Automatic door closer - Google Patents

Description

The invention relates to an automatic door closer with a closer shaft loaded by a spring arrangement in the closing direction, which guides the displaceable piston of a damping hydraulic piston-cylinder unit, the pressure chamber with the unpressurized space on the one hand via a throttle device and a return channel to the pressure chamber opening check valve is connected.

The purpose of door closers is to keep door leaves closed in the normal case, because they can only perform the protective functions intended for them, such as fire protection, radiation protection, sound insulation, burglary protection and privacy protection, when closed. On such doors, door closers with hydraulic damping are usually provided, which have a spring arrangement with the aid of which the energy required for the automatic closing of the door leaf is stored during manual opening and is used to close the door leaf after the door opening process has ended. The automatic door closing movement is usually dampened by a hydraulic throttle system and thus offers great convenience in terms of reliability and safety.

The door closers that meet today's standards now have sophisticated, high-quality technology that includes the function of securely closing the door leaf and, at the same time, ensures harmlessness and largely noiselessness during the closing process thanks to the hydraulic damping systems. Door closers with hydraulic damping are standardized and - insofar as they meet the quality requirements of the standards and goods directives - are constantly monitored for quality.

Although the known door closers meet a high technical standard, they all have the common disadvantage that the energy required for the closing movement of the door leaf must first be applied by the door inspector in addition to the opening resistance of the door leaf during the opening movement. This disadvantage is particularly noticeable in the case of large and heavy doors which require a correspondingly large amount of locking, and in particular when they are e.g. B. by children or older, weaker people. Sometimes this group of people is unable to open such a door without outside help.

In order to alleviate this generally known defect, the industry offers door closers with locking devices, such as have become known for example from DE-OS 25 41 790. In this known door closer, the door leaf is determined from a certain opening angle in that the return opening in the piston is closed by a needle penetrating this opening. In addition to this reflux opening in the piston, which can be closed by the needle, this known door closer has a reflux duct provided with a throttle device, which can be opened or closed by an electromagnetically supported holding valve. When this second return flow channel is closed by the electromagnetic valve, the door leaf remains in its open position when the return line located in the piston of the door closer is also closed by the needle. Only when the electromagnetic holding valve is opened in the event of danger is the closing spring able to move the piston and thus also the door leaf into the closed position. These doors must therefore be constantly monitored in order to ensure that a certain alarm criterion, e.g. B. Fire, the locking device to solve immediately to give the door closer the required property for self-closing of the door leaf.

In another door closer known from DE-OS 27 51 859, the disadvantage of the difficult opening movement of the door leaf is normally avoided by holding the closing energy stored during the first opening process. In this so-called free-wheel door closer, the closing spring is blocked in its pretensioned position by a second piston being connected between the piston engaging the closer shaft and the spring arrangement. The return flow line passing through the second piston can also be closed by an electromagnetic switching valve or opened in the event of danger. In the normal state, as a result of the closed return flow line, the pressure medium cannot flow out of the pressure chamber receiving the piston which engages with the closer shaft, so that the piston which is connected to the closer shaft in motion can be pushed back and forth in the pressure chamber without resistance, so that the clutch is coupled to the closer shaft Door leaf can also be easily opened or closed manually. Apart from the fact that the door, if it is not manually closed by the attendant, remains in its open position, the door closers of these door leaves must be permanently coupled to monitoring devices such as smoke detectors or fire alarms, so that the door leaf closes automatically in the event of danger.

However, such door closers have the disadvantage that either the door leaf is constantly open or the door leaf must be constantly closed, which in most cases is certainly not done because today's modern man is generally already used to self-closing doors.

Of course there is also Door automats, by means of which the door leaves are automatically opened in front of the inspector and automatically closed again after inspection. However, these devices are so complex both in technical terms and in terms of costs that they no longer fall under the category of the above-mentioned door closers.

The object of the present invention is to provide a door closer of the type mentioned, which brings about a self-closing of the door leaf at any time and after each door opening and yet enables effortless opening of the door leaf without substantial effort.

This object is achieved in that between the piston and the spring arrangement, a self-movable support member is connected, which can be driven by external energy in the sense of a spring preload depending on the door actuation. As a result, the viewer of door leaves equipped with such door closers does not need to apply any force for the pretensioning of the spring arrangement, so that the door opening process is made considerably easier. The energy required to tension the closing spring during the door opening movement is applied by external energy, as a result of which the spring arrangement is automatically preloaded. After the door opening process has ended, the spring arrangement releases the stored energy for the automatic door closing movement.

An advantageous embodiment of the invention is achieved in that the support member is designed as a threaded nut acted upon by the spring arrangement, which is guided non-rotatably in the cylinder housing and is penetrated by a spindle having a movement thread, which engages through the spring arrangement and rotates in the door closer housing, but is axially immovably supported and over a transmission having a brake is coupled to an electric motor. By using a movement thread, it is possible that after the energy storage in the spring arrangement by releasing the gear brake, the spring arrangement presses back the support member and thus also the piston acted upon by it under hydraulic damping action, so that the door leaf can be returned in its closed position in a known manner.

Instead of an electromechanical pretensioning of the spring arrangement, it is also conceivable, according to a further exemplary embodiment of the invention, to design the support member as a pressure disk acted upon by the spring arrangement, which is connected to a piston rod which passes through the spring arrangement and is guided longitudinally displaceably in the door closer housing and which is connected to a tensioning piston in a engages extension cylinder separate from the master cylinder, which is connected to a pressure medium circuit operated by a pump controlled by an electric motor. In order to be able to pre-tension the spring arrangement in advance of the door opening movement, according to an advantageous embodiment of the invention the movement of the support member is controlled by an electronic control logic triggered by the door actuation. This makes it possible for a door contact to be triggered when the door handle is depressed, for example, which activates the control logic in the sense that the spring preload is already initiated for a certain partial amount of the piston stroke. In order to maintain this leading spring preloading movement and also to emit impulses for the purpose of releasing the closing energy, according to a further embodiment feature of the invention, a plunger coil system which can be actuated by negative pressure and which generates control pulses for the electronic control logic is assigned to the pressure chamber in front of the piston.

• Figur 1 den erfindungsgemäßen Türschließer im Längsschnitt mit dem in anderer Ebene liegenden, angedeuteten Drosselkanal und einer angeflanschten, schematisch dargestellten Motor-Getriebeeinheit für einen Zugspindelantrieb,
• Figur 2 das weitere Ausführungsbeispiel eines Türschliessers mit einem Fortsatzzylinder mit integrierter Motorpumpe.

The invention is shown in exemplary embodiments on the drawing, for example, and is explained in more detail below. Show it :

• 1 shows the door closer according to the invention in longitudinal section with the indicated throttle channel lying in another plane and a flange-mounted, schematically illustrated motor-gear unit for a traction screw drive,
• Figure 2 shows the further embodiment of a door closer with an extension cylinder with an integrated motor pump.

The door closers shown in FIGS. 1 and 2 have an elongated, rectangular housing 10, through which a cylindrical bore 11 extends, which is closed on both sides with plugs to be explained later. Crossing through the housing 10 extend in a known manner two mutually aligned, not shown stepped bores, which receive bearing inserts with sealing rings, in which the closer shaft 12 is rotatably guided. In its middle length range, the closer shaft has a pinion 13. Both end parts of the closer shaft 12 are prepared for the rotationally fixed reception of a link arm, not shown, for establishing a connection between the door frame and the door leaf by, for example, attaching square edges.

In the cylinder bore 11, a piston 14 is arranged so as to be longitudinally displaceable, which consists of a first piston head 15, a second piston head 16 and a web 17 arranged between them. This web 17 is designed as a rack which meshes with the pinion 13 of the closer shaft 12. Rotational movements of the closer shaft 12 therefore cause longitudinal movements of the piston 14 and vice versa. In the piston head 15 sealed against the cylindrical bore 11, a check valve 18 is arranged, which opens to the pressure chamber lying to the left of the piston head 15. In addition to the check valve 18, a spring-loaded pressure relief valve 19 is arranged in the piston head 15, which opens when an overpressure develops in the pressure chamber 20 to the left of the piston head 15, as it occurs for example, if the door leaf is forced shut.

In the housing 10 extends parallel to the cylinder bore 11, a stepped bore 21, into which a throttle cone cooperating with a seat formed by a step is screwed on the left-hand end to form a throttle valve 22. This throttle valve has a throttle cone 23 which can protrude into the stepped part of the stepped bore 21 to restrict the flow. Two transverse bores 24 and 25, which are connected to the cylinder bore 11, open into the stepped bore 21 which receives the throttle valve 22 while leaving an annular space to the left of the throttle cone 23. From the stepped bore 21 continues to the region of the cylinder bore 11 occupied by the web of the piston 14, a transverse bore 26 likewise cannot be covered by the piston head 15.

The left-hand end region of the door closer housing 10 is closed by a plug 27 screwed into the cylinder bore 11 with the aid of a sealing ring. This plug 27 has a chamber 28 covered by a membrane towards the pressure chamber 20, into which a pointed plunger 29 of the spring-loaded core bolt 30 of a moving coil system 32, which plunges into a ring coil 31, projects.

Adjacent to the piston head 16 of the piston 14, a support member 33 is arranged in the cylinder bore 11, which is acted upon by a spring arrangement 34 in the sense of a displacement of the piston 17 to the left - ie in the closing direction of the door leaf. Which functions as a closing pressure spring spring assembly 34 is at the other _'supported on a housing 10 tightly closing plug 35th In the embodiment shown in FIG. 1, the support member 33 consists of a threaded nut which projects with a nose 37 into a longitudinal groove 38 in the cylinder bore 11. So that the threaded nut 36 is longitudinally displaceable, but non-rotatably arranged in the door closer housing 10. The threaded nut 36 engages over a spindle 39, which is sealed in the stopper 35 and can be rotated but axially immovably mounted and has a moving thread, which may be driven by an electric motor via a gear stage 41 and a reduction gear 42 having a brake. An electronic control logic 44 is connected between the power supply and the electric motor 43, which can be controlled on the one hand by the moving coil system 32 and on the other hand by a door contact 45. This door contact 45 may advantageously be actuated by the latch of the door leaf interacting with the striking plate of the door frame - ie by the door handle.

In the embodiment shown in FIG. 1, the support member 33 consists of a thrust washer 46 which is axially displaceably guided in the cylinder bore 11 and which is firmly connected to a piston rod 47 penetrating the spring arrangement 34 in the longitudinal direction. The piston rod also penetrates the sealing plug 35, which continues into an extension cylinder 48 adjoining the master cylinder 11. In this extension cylinder 48 there is a tensioning piston 49 connected to the piston rod 47. This schematically illustrated extension cylinder also houses in its housing part a pump 50 operated by an electric motor 43 and a control valve 51. In the extension cylinder 48 open in front of and behind the piston taking into account the entire piston stroke, the channels 52 and 53, between which the pump 50 is connected. In parallel to the pump 50, a control valve 51 is connected between the channels 52 and 53, through which the pressure medium flow can only flow via the pump 50 when the control valve is blocked, while when the control valve is open, the pressure medium via the parallel channel directly from the cylinder space in front of the tensioning piston 49 in the latter can flow back bypassing the pump.

For the description of the functioning of the door closer according to the invention, it is assumed that the door leaf is closed. If the door latch 45 is now actuated via the latch, the control logic 44 is activated by the triggered pulse in such a way that the motor 43 is switched on and either in the case of the exemplary embodiment according to FIG. 1 via the gear 42 and the spindle 39 or in the case of 2 via the pump 50 and the tensioning piston 49 - the support member 33 is moved to the right against the force of the spring arrangement 34. The displacement of the support member 33 is set by the control logic. Determines engine running time, which may be set such that the support member 33 has advanced by an amount corresponding to a certain door opening angle. If the door leaf is now actually opened, the piston 14 is moved, a negative pressure being generated in the pressure chamber 20, which is converted into an electrical pulse for the control logic 44 by the schematically illustrated moving coil system 32. The motor 43 then receives the command to further bias the spring assembly 34, always according to the amount leading the door leaf movement, which was set when the door was closed. If the door is now opened more quickly, a correspondingly greater negative pressure is established in front of the piston in the pressure chamber and the measured value then changed by the moving coil system 32 is converted by the control logic 44 into a command to the motor 43 "rotate faster. At the moment when the door leaf stops opening, the negative pressure in the pressure chamber in front of the piston head 15 rises to the normal value, whereby the change in the measured value of the moving coil system is converted by the control logic into the "stop" motor command. In the embodiment shown in FIG. 1, the brake in the transmission 42 engages immediately when the engine is running and thus holds the threaded nut 36 in the set position. In which From Fig. 2 apparent embodiment, the pump 50 no longer promotes pressure medium after the motor 43 is stopped, so that the set volume state in front of and behind the tensioning piston 49 is maintained and this thus the pressure plate 46 in the position reached against the closing force of the piston rod 47 Holds spring assembly 34.

After a short, preselected waiting time, the control logic 44 now issues the command “Relieve the spring and in the embodiment shown in FIG. 1, the brake of the transmission 43 opens, while in the embodiment shown in FIG. 2, the control valve 51 is reversed in such a way that the Pressure medium from the cylinder space in front of the tensioning piston 49 can pass through the channel 53 into the channel 52 and from there into the cylinder space behind the tensioning piston 49. In both cases, the spring arrangement 34 is thus able to push the support member 33 forward, as a result of which the piston 14 is also pushed by the support member in the direction of the front cylinder end comprising the moving coil system 32. So that the closer shaft 12 is rotated in the closing direction via the rack 17, so that the door leaf is moved in the closed position. As with any conventional door closer, the door closing movement is hydraulically damped by the throttle valve 22 which engages in the channels 26, 21, 24, 25. As soon as the door leaf is completely closed and the lock latch falls into the striking plate, the door contact 45 is actuated again in the closed direction and the electric motor 43 receives its first command again in order to move the support member 33 into its forward stroke corresponding to a preselected door opening angle.

However, if no door is opened after the first door handle is actuated, the control logic 44 reacts in the same way as when the door opening movement has ended and, after the predetermined time, gives the electric motor 43 or the brake of the transmission 42 or the control valve 51 the command "Relieve the spring", so that the full closing force again acts on the piston 14 and is therefore also present on the door leaf.

In the event of a power failure, of course, the electric motor and also the control logic are ineffective, which means that the spring arrangement 34 remains unaffected, so that the support member 33 is constantly in contact with the piston 14 by the spring arrangement and constantly acts on it in the closing direction. In this situation, the spring arrangement must of course always be preloaded every time the door leaf is opened. It follows from this that the door closer is designed in such a way that the safety concept takes precedence and self-closing of the door leaf is ensured in the form of electricity in the event of external power failure.

As already mentioned, the embodiments shown represent the invention only by way of example, which is by no means limited to this. Rather, various changes and other configurations of the invention are possible. For example, it is conceivable that the current representing the external energy can also be replaced by other known forms of energy. It should also be pointed out that the above-described moving coil system 32 is only given as an example and can be replaced by other known systems which are able to convert the movement of the piston into information for the control logic, which also does not necessarily have to be electrical.

Claims (5)

1. An automatic door closer including a closer shaft (12) biassed by a spring arrangement (34) in a closing sense, and which guides the movable piston (14) of a hydraulic piston-cylinder unit serving for damping purposes, whose high-pressure chamber (20) is connected with the low-pressure chamber on the one hand via a return flow passage having a restrictor and on the other hand via a check valve (18) opening towards the high-pressure chamber (20), characterized in that the piston (14) and the spring arrangement (34) have connected therebetween a self-moving support member (33) adapted to be driven by external energy in the sense of a spring bias as controlled in dependence on the door actuation.

2. A door closer as claimed in the claim 1, characterized in that the support member (33) is designed as a threaded nut (36) controlled by the spring arrangement (34), which is non-rotatably guided in the cylinder housing (10) and penetrated by a spindle (39) having a movement thread (40), which extends through the spring arrangement (34) and is supported in the door closer housing (10) for rotating movement, but axially unmovable and is coupled with an electric motor (43) via a gearing (42) having a brake.

3. A door closer as claimed in the claim 1, characterized in that the support member (33) is designed as a pressure disk (46) controlled by the spring arrangement (34), which is connected with a piston rod (47) extending through the spring arrangement (34) and guided in the door closer housing (10) for longitudinal movement therein and which has a tensioning piston (49) engaging in an extension cylinder (48) separated from the main cylinder (11), connected into a fluid flow driven by a pump (50) controlled by an electric motor (43).

4. A door closer as claimed in any one of the preceding claims, characterized in that the movement of the support member (33) is controlled by an electronic control logic (44) released by the actuation of the door.

5. A door closer as claimed in any one of the preceding claims, characterized in that the high-pressure chamber (20) in front of the piston (14) has associated therewith a moving coil system (32) actuated by low-pressure, for generating control pulses for the electronic control logic (44).

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