DE9203873U1 - Door closer with combined valve for opening damping and closing speed - Google Patents

Abstract

The door closer has a fluid-damped piston (32) which is movable in a housing (21) counter to a spring force (5, 6) and which subdivides the housing (21) into two pressure spaces (10, 11). A flow channel (45) connects the two pressure spaces (10, 11). Arranged in the flow channel (45) is a valve (30) which determines both the opening damping and the closing speed of the door closer. A door closer which is simpler to produce and simpler to adjust is thereby obtained. <IMAGE>

Description

Door closer with combined valve for opening damping and closing speed 5

The innovation concerns a door closer with a fluid-damped piston that moves against a spring force in a housing as the door moves, which piston divides the housing into two pressure chambers.

Such door closers are well known. When the door is opened, the fluid is first conveyed by the piston moving in the housing from the first pressure chamber through a bypass opening in the piston into the pressure-free chamber; in this phase of movement, the door opening is practically not dampened in order to enable the door to be opened easily. When the door opens to an angle of approx. 70 degrees, a control rod closes the bypass opening. The fluid is then directed through a special flow channel and a first adjustable valve (throttle valve) into the second pressure chamber. The valve's setting determines the dampening of the opening door for the rest of the door opening path. To close the door, the piston is moved in the opposite direction by the tensioned spring. A second flow channel with a second adjustable valve (control valve) for the fluid moved back by the piston from the second pressure chamber to the first pressure chamber determines the closing speed of the door. Shortly before the closing position is reached, a third flow channel with a third adjustable valve is usually activated to enable the so-called final stroke, i.e. to allow the door to fall into the lock with sufficient speed.

The known solution is complex to manufacture, since the opening damping and the

SIC/IO 45 553

31.01.1992

Closing speed requires a flow channel to be formed in the housing and an adjustable valve to be provided. It has also been shown in practice that the correct setting of the opening damping has not been possible up to now, as the amount of oil (pressure medium) to be throttled is too small. In practice, it has only been possible to keep the valve open or closed. When the valve is open, the opening damping is switched off. When the valve is closed, the amount of oil to be displaced in the pressure chamber is released via the pressure relief valve.

The main disadvantage of this is that a door that opens slowly is braked just as much as a door that opens quickly. However, the throttle valve has the task of increasing the damping when the door is pushed open violently, and reducing or even switching off the damping when the door opens slowly.

It has also been shown that contamination of the throttle valve and control valve can impair the function of the door closer.

The innovation is therefore based on the task of creating a door closer which does not have the above-mentioned disadvantages and which is in particular simpler to manufacture and easier to adjust and in which valve contamination does not occur.

This is achieved in a door closer of the type mentioned above by providing a flow channel for the fluid in the housing, which connects the two pressure chambers and in which a valve is arranged, which determines both the opening damping and the closing speed of the door closer.

The arrangement of only one valve that fulfils the function of throttle and control valve, and only one flow channel in the housing for the opening damping function and the closing speed

function, simplifies production considerably. The valve can also be arranged anywhere in the flow channel. Since only one valve needs to be set for the functions mentioned when operating the door closer, setting is also made considerably easier. It has been shown that a setting value that is correct for both functions can be achieved with the same valve, especially with a heavy door. Since the closing force (spring force) is increased, the valve must be closed slightly in order to achieve the correct closing speed. This also synchronously reduces the throttle gap of the opening damper. This in turn means that the opening damper is increased and is precisely adapted to the weight of the door.

Valve contamination is also practically non-existent, as the fluid flows through the valve from both sides during each opening/closing process.

In the following, examples of the innovation are explained in more detail using the drawings.

Figure 1 is a plan view of a door closer;

Figure 2 is a sectional view of the door closer taken along line A-A of Figure 1;

Figure 3 is a sectional view taken along the line E-E of Figure 1;

Figure 4 is a sectional view along the line D-D of Figure 1 with the valve arranged transversely to the flow channel;

Figure 5 is a sectional view taken along line C-C of Figure 2;

Figure 6 is a partial view of a flow channel with a valve arranged axially in the flow channel;

Figure 7 is a partially sectioned detailed view of the throttle valve.

Figure 1 shows a top view of a door closer 1 with a cuboid-shaped housing 21. The housing 21 is preferably formed by a profile piece, which is closed at the front by means of a plate 22. A flange 20 is provided on each of the plates 22, which serves to fasten the door closer to the door or door frame. The pressure-tight connection of the profile piece with the plates 22 is made by means of screws or rivets or by welding, preferably by electron beam welding. An O-ring 25 is provided for sealing. The profile piece is manufactured by extrusion or continuous casting. The profile piece consists of aluminum, for example. Preferably, the flow channels described below are already provided in the profile; in this case, the production of the flow channels by drilling is unnecessary. The flow channels are generally of round cross-sectional shape, but can also have other cross-sectional shapes.

Figure 2 shows a section along the line A-A of Figure 1. The piston 32 is arranged in the hollow cylindrical, fluid-filled interior (Figure 5) of the housing 21. This is designed as a hollow piston with the cavity 8. On the inside of the piston, the piston is designed as a rack, which engages in a toothed axis 41 (closer axis, Figure 5) that is mounted in the housing 21 by means of a needle bearing 42. The closer axis is coupled to the door or the door frame in a known manner (not shown), so that the door movement is converted into a rotation of the closer axis or into a linear movement of the piston 32. The piston 32 divides the cylindrical cavity of the housing into two pressure chambers 10 and 11. In the position shown, the piston is in one of its end positions, which corresponds to the piston position when the door is closed. When the door is opened, the piston 32 is moved via the toothed axle and rack

against the force of the springs 5, 6 to the right (in the drawing). The oil in the pressure chamber can initially flow through the bypass opening 17 in the piston flange 36, whereby the piston 32 experiences practically no resistance from the oil filling of the housing 21. From a door opening angle of approx. 70 degrees, the control rod 82 closes the bypass opening. In Figure 2, the control rod 82 is shown as a non-spring-loaded control rod, which penetrates into the bypass opening 17. The control rod can also be designed as a spring-loaded control rod, which only presses the bypass opening and then moves with the piston in a spring-loaded manner. The control rod does not penetrate into the bypass opening. The oil in the pressure chamber 11 now flows solely through the flow channel 45 (Figure 3) from the pressure chamber 11 to the pressure chamber 10. The flow channel 45 is connected to the pressure chamber 11 or 10 via a bore 27. In the flow channel, the valve 30 is provided as a throttle for the oil flow, so the opening damping determined by the valve comes into operation. In the position shown, the valve 30 completely blocks the flow channel 45. By screwing the valve 30, designed as a screw, into the corresponding seat in the housing 21, the constricted throttle area of the valve with a smaller diameter enters the flow channel 45 and partially releases it, whereby the oil flow is adjustable throttled. The adjusting screw of the valve 30 can be seen from above in Figure 1. Turning the screw in reduces the throttling of the oil and thus the opening damping of the door; accordingly, the clockwise screw movement is marked with a minus sign.

The valve 30 is preferably made of a plastic material with a high coefficient of thermal expansion. This allows viscosity changes of the fluid to be compensated for when the temperature changes. The pressure-tight closure

at the front sides of the flow channel is carried out by a ball or plug 35 made of plastic.

When the door is closed by the door closer, the piston 32 is moved to the left by the spring force of the tensioned spring 5. The fluid in the pressure chamber 10 is pressed by the piston 32 or by its closing piston flange 34 via the bore 27 into the flow channel 45, where the valve 30 in turn acts as a throttle for the fluid, which after the valve passes from the flow channel via the bore 27 into the pressure chamber 11. When the door is closed, the same valve 30 that already determined the effective opening damping determines the closing speed of the door. Surprisingly, it has been shown that both functions can be easily fulfilled by the one valve.

The continuous flow channel 45 shown also allows the valve to be installed at any point along the flow channel. The valve 30 can be arranged transversely to the flow channel 45, as shown in Figure 4. However, it can also be located axially in the flow channel, as shown in Figure 6. In this case, a special adjusting screw 4 is provided for adjusting the axially positioned valve body 40 against the force of a return spring 43.

Figure 4 shows a further flow channel 55, which is also arranged in the housing 2 outside the area of the shaft for the tooth axis 41. A short section of this flow channel serves as a fluid line for the final stroke function of the door closer, in which the closing damping is significantly reduced at the end of the closing path so that the door falls securely into the lock. For this purpose, the fluid from the pressure chamber 10 is guided via channel holes 46, 47 via the flow channel 55 into the piston cavity 8 in order to reduce the damping of the closing process by the fluid in the pressure chamber 10. A valve 50 is also arranged in the flow channel 55 in order to

to be able to adjust. The flow channel 55 is also sealed using plastic balls or plugs 51. Since only a short section of this flow channel 55 is used for the end stroke adjustment, the rest can be used for other purposes. The unused part can be separated from the end stroke part using a plug 53, for example. The rest of the flow channel can now be used as an expansion channel. This means that the flow channel is connected to the central pressureless space using a channel bore.

A pin 57 is also pressed into this channel bore, but this does not prevent the permeability. The pin serves as a stop for the plug 53. The pin is therefore a dowel pin or a non-round pin, which ensures the permeability of the bore.

A ball 58 (or several balls) made of plastic or rubber is now inserted into the flow channel. The ball 58 is inserted at room temperature during assembly up to the pin 57 and seals an air-filled flow channel part (compression chamber) located between the ball 58 and the plug 51 from the oil-filled flow channel part (expansion chamber 56), which is connected to the middle chamber. If the temperature of the door closer increases, this results in an expansion of the oil volume. The increase in the oil volume in the door closer creates excess pressure in the door closer, which acts on the ball 58. This moves in the flow channel towards the plug 51 and thus increases the oil absorption volume of the door closer.

When the door closer cools down, the oil volume becomes smaller, the compressed air in the compression chamber between the ball 58 and the plug 51 now presses the movable ball 58 back against the stop pin 57, so that no vacuum is created in the door closer. This makes it possible to fill the door closer completely with oil without the temperature

If the door closer is increased in temperature, it will fail due to the internal overpressure of the fluid.

Preferably, the piston 32 is made of

several parts, a rack as the middle part, an opening piston flange 36 and a closing piston flange 34, whereby these parts are screwed together. Such a piston is particularly easy to manufacture and inexpensive. Preferably, a sliding film 33 made of polytetrafluoroethylene (PTFE) is also provided between the rack and the inner wall of the housing 2 in order to improve the sliding properties of the piston (usually made of steel) in the housing (usually made of aluminum).

Preferably, an adhesive disk 92, e.g. made of rubber or PVC, is also inserted between the clamping plate 91 and the spring 5 in order to prevent the clamping plate 91 from rotating when adjusting the spring preload using the clamping screw 71. Preferably, such an adhesive disk is also provided between the spring support on the piston flange 36 and the spring.

Preferably, the door closer

two springs 5 and 6 are arranged one inside the other. The longer spring 5 extends between the piston flange 36 and the clamping plate 91, which can be moved in the housing by means of a clamping screw 71 accessible from the outside of the housing 21. The spring preload acting on the piston is set by means of the clamping plate and the clamping screw. In the middle preload position shown, in the piston rest position shown (door closed), only the long spring 5 acts on the piston. The short spring 6 is not effective. When the piston is moved to the right (in the drawing) due to the door opening movement, a spring force is initially exerted on the piston in accordance with the spring characteristic of the spring 5, corresponding to a door closer size 3. After a predetermined time, which depends on the relative position of the clamping plate

and the piston dependent door opening angle (approx. 60 degrees), the short spring 6 is also loaded by the piston in such a way that the spring 6 becomes effective. This results in the added spring characteristic curve.

When the piston is pushed back by the springs when the door is closed, the reverse process occurs. Initially, both springs 5, 6 are effective (added spring characteristic curve), from a door opening angle of approx. 60 degrees and less, only the spring acts on the piston 32 with a correspondingly reduced spring force.

When the spring preload is set to the minimum, i.e. the clamping plate is in its right end position, a different process occurs. The short spring 6 is not used at all up to a door opening angle of 90 degrees (or more), since the piston travel is not sufficient to allow the short spring between piston 32 and clamping plate 91 to take effect. When opening and closing between 0 and 90 degrees, the door closer only works with the spring characteristic of the long spring 5, corresponding to a door closer size. When the spring preload is set to the maximum, the clamping plate 91 is in its right end position. Now the distance between the rest position of the piston and the clamping plate is such that the short spring 6 also always acts on the piston from the start when opening and closing. The springs act according to the added spring characteristic.

This design of the door closer means that the DIN values for 2 degrees and 90 degrees door opening can be achieved for all pre-tension settings.

Figure 7 shows a preferred embodiment of the valve 30, which is arranged transversely to the flow channel. The valve has a non-linear throttle curve. This measure, together with the known design of the valve as a thermostatic valve, which changes its length with the temperature

changes it is possible to keep the oil flow through the flow channel essentially independent of temperature.

Claims (16)

Protection claims 1. Door closer with a fluid-damped piston (32, 34, 36) that is movable against a spring force in a housing (21) by the door movement, which piston divides the housing into two pressure chambers (10, 11) for the fluid, characterized in that a flow channel (45) for the fluid is provided in the housing (21), which connects the two pressure chambers (10, 11) and in which a valve (30) is arranged, which determines both the opening damping and the closing speed of the door closer. 2. Door closer according to claim 1, characterized in that the housing (21) is formed by a hollow profile, which is provided with a cover plate (22) on each end face. 3. Door closer according to claim 2, characterized in that the end plate (22) has a fastening flange (20) for fastening the door closer to the door or the door frame. 4. Door closer according to claim 2 or 3, characterized in that the flow channel (45) is formed by a profile recess of the hollow profile. 5. Door closer according to one of claims to 4, characterized in that the flow channel is sealed on the end plate side by means of a plug (35) in the flow channel. 6. Door closer according to one of claims to 5, characterized in that the valve comprises an adjustable valve body (30) arranged transversely to the flow channel (45), by means of which the fluid circulating through the flow channel can be adjustable and throttled. 7. Door closer according to one of claims 1 to 5, characterized in that the valve comprises an adjustable valve body (40) arranged longitudinally to the flow channel (45), by means of which the fluid circulating through the flow channel can be throttled in an adjustable manner. 8. Door closer according to one of claims 1 to 7, characterized in that the piston forms a pressure-free third chamber (8) in itself, and that a second flow channel (55) is provided, through which, at a predetermined piston position, the one pressure chamber (10) can be connected to the pressure-free chamber (8) in order to bring about a final impact of the door. 9. Door closer according to claim 8, characterized in that an adjustable valve (50) is provided in the second flow channel in order to adjustably throttle the fluid flow for the final stroke. 10. Door closer according to claim 8 or 9, characterized in that in the second flow channel (55) a section is provided which is separated from the connection of the one pressure chamber (10) with the pressure-free chamber (8), and that this section is separated into two parts by a sealing element (58) which can be displaced in the flow channel, wherein one part is closed and filled with air, and the other part is fluidically connected to the pressure-free chamber (8). 11. Door closer according to one of claims 1 to 10, characterized in that the piston is composed of several interconnected piston parts (32, 34, 36). 12. Door closer according to claim 1, characterized in that the piston is composed of a rack (32), an opening piston flange (36) and a closing piston flange (34), which parts are screwed together. 13. Door closer according to claim 11 or 12, characterized in that a sliding film is provided on the piston (33) is arranged to reduce the friction between the piston and the inner housing wall. 14. Door closer according to one of claims 1 to 13, characterized in that a preload-adjustable spring force acts on the piston, that at least two springs (5, 6) are provided, and that one spring (5) is always acted upon by the piston, and the other spring (6) can be acted upon by the piston depending on the preload setting. 15. Door closer according to one of claims 1 to 14, characterized in that the valve is designed as a thermostatic valve, the valve body (30, 40) of which carries out a temperature-dependent change in length in order to reduce the influence of the temperature on the fluid flow, and that the throttle angle of the valve (30, 40) is not linear in order to essentially eliminate the influence of the temperature on the fluid flow. 16. Door closer according to one of claims 1 to 15, characterized in that an adhesive disc (92) for increasing the friction between the clamping plate and the spring is arranged between a tensioning plate (91) adjustable by means of a tensioning screw (71) for adjusting the spring preload and the spring (5).