Door closer with magnetic directional control valve

Abstract

Door closers (41), in particular swing door closers, with hold-open or free-running function, including door closers (41) a door closer housing (42), an output shaft (48) that can be connected to a door, a piston assembly (94) connected to the output shaft (48) and guided in the door closer housing (42), a closing spring (56), a piston rod (54) arranged to connect the piston assembly (94) with the closing spring (56), a hydraulic locking chamber (61) designed to block the closing spring (56), and a solenoid directional control valve (1), in particular a 3 / 2 solenoid directional control valve, wherein a closing damping chamber (58) is formed on one side of the piston assembly (94) facing away from the piston rod (54) between the door closer housing (42) and the piston assembly (94), and wherein the magnetic directional control valve (1) controls at least the pressures in the closing damping chamber (58) and in the blocking chamber (61).

Description

[0001] The invention relates to a door closer with a magnetic directional control valve.

[0002] The current state of the art distinguishes between door closers and door operators. With door closers, the door must be opened manually by a person. During the opening process, energy is stored, for example in a closer spring, and the door closer can then close the door automatically using this stored energy. In contrast, a door operator is a device that uses additional auxiliary energy, such as an electric motor and hydraulics, to open and close the door automatically. Significant differences become apparent when examining the hydraulic circuits in door operators and door closers. Door operators always contain a motor and a pump that generate the necessary hydraulic pressure. The corresponding pressure chambers are then actively pressurized with hydraulic pressure, which causes the door to open. The pressure is thus generated within the door operator by its internal components: the motor and the pump.In contrast, pressure chambers in a door closer fill through chamber expansion and the drawing in of hydraulic oil from other parts of the door closer. Here, opening the door provides the energy for the closer spring and for building up pressure in the door closer. Consequently, the force and torque curves, as well as the resulting loads, are fundamentally different in a door closer and a door operator.

[0003] DE 34 23 242 C1 discloses a door closer comprising a closing-direction closing shaft that guides the movable piston of a hydraulic piston-cylinder unit serving a damping purpose. The pressurized chamber of the piston-cylinder unit is connected to the unpressurized chamber on one side via a return channel with a throttling device and on the other side via a check valve opening towards the pressurized chamber. A self-moving support element is interposed between the piston and the spring assembly. This support element can be actuated by external energy in the form of a spring preload, depending on the door operation. However, to constantly indicate to the door user that the door leaf they are operating has a door closer and thus prevent accidents, the damping piston is constantly biased in the closing direction by a second energy storage device that exerts a lower force than the spring assembly.

[0004] Further state of the art is shown in DE 10 2004 061 619 B3, US 4 115 897 A and WO 2006 / 066 666 A1.

[0005] The object of the present invention is to provide a door closer that is very slim and cost-effective to manufacture, and therefore can also be used as an integrated door closer in, for example, a door frame or a door. Furthermore, the door closer should have a hold-open function or a free-swing function.

[0006] The problem is solved by the features of the independent claims. The dependent claims relate to advantageous further developments of the invention.

[0007] The problem is thus solved by a door closer, in particular a swing door closer with a hold-open or free-running function, comprising a door closer housing, an output shaft connectable to a door, a piston assembly connected to the output shaft and guided in the door closer housing, a closing spring, a piston rod arranged for connecting the piston assembly to the closing spring, and a hydraulic locking chamber designed to block the closing spring. Furthermore, the door closer comprises a solenoid directional control valve, in particular a 3 / 2-way solenoid directional control valve, wherein a closing damping chamber is formed between the door closer housing and the piston assembly on a side of the piston assembly facing away from the piston rod, in particular on the side of a damping piston. According to the invention, the solenoid directional control valve controls at least the pressures in the closing damping chamber and in the locking chamber.

[0008] Preferably, the door closer comprises a free-swing arrangement designed to allow translational movement of the piston assembly decoupled from the closer spring when the closer spring is blocked. Alternatively, in the hold-open function, the closer spring is rigidly twisted to the piston assembly, so that blocking the closer spring simultaneously locks the piston assembly and thus the door.

[0009] The solenoid valve allows the locking chamber to be hydraulically sealed. This prevents the pre-tensioned closing spring from relaxing, thus activating the door closer's free-running function. Switching the solenoid valve releases the pressure in the locking chamber, allowing the closing spring to move the piston assembly, for example in the event of a fire, and thus close the door via the output shaft.

[0010] Door closers with a free-swing function are primarily used in facilities for people with disabilities, senior living facilities, and kindergartens, as well as for securing fire doors. In combination with a fire alarm system, they ensure the closing of these doors to prevent the spread of smoke and fire, without requiring users to constantly engage the closing mechanism of conventional door closers. Fire doors, in particular, require very strong closing springs to ensure the door closes securely even in drafty corridors. Having to tension these closing springs every time the door is opened is especially problematic for children, the elderly, and the infirm. The free-swing function allows the closing spring to be pre-tensioned only once and remain engaged until a fire occurs.Due to its very narrow width, the door closer presented can be installed invisibly in the door leaf or frame, which does not impair the appearance of the door and protects against damage from vandalism.

[0011] Preferably, the door closer comprises a fluid-tight partition arranged in the door closer housing between the piston assembly and the closing spring, with the piston rod passing fluid-tight through the partition. The partition is fixed in position relative to the door closer housing and sealed. A mechanical seal is preferably used between the piston rod and the partition.

[0012] Furthermore, the door closer advantageously includes a spring tension piston guided within the door closer housing and bearing against the closer spring. The piston rod thus transmits the force from the piston assembly to the spring tension piston. The closer spring rests against the spring tension piston.

[0013] Advantageously, the locking chamber is formed between the partition and the closing spring tensioning piston. The piston assembly with the output shaft is thus located on one side of the partition. The piston rod transmits the forces through the partition to the other side, where the locking chamber, the closing spring tensioning piston, and the closing spring are arranged.

[0014] For the freewheel function integrated into the door closer mechanism, the closer spring, also called the energy storage spring, must be held in a pre-tensioned position by means of the hydraulic locking chamber to prevent the door from closing immediately after manual opening. Since the closing spring's direction of action is directed towards the output shaft via the piston assembly, an additional closing spring tensioning piston is preferably used, which acts on the piston assembly via the piston rod. In conjunction with the piston rod and the partition, this creates the hydraulic locking chamber for the hydraulic locking of the closing spring. The piston rod extends through the locking chamber, which is why the locking chamber can also be described as an annular chamber. This design of the door closer according to the invention clearly illustrates a crucial difference between previously known door drives and the door closer presented here.In the previously known door drive, a hydraulic pump actively pumps pressurized oil volume into the pressure chambers, thereby pre-tensioning an energy storage spring via a spring-loaded piston. In contrast, in the presented door closer, the oil volume corresponding to the stroke is displaced from other housing areas into the locking chamber during the manual opening process, and the outflow from the locking chamber is blocked, for example, by a solenoid valve. Thus, in the door closer presented here, the stored force of the closing spring is absorbed by the oil pressure and cannot transmit torque to the output shaft via the piston assembly.

[0015] Preferably, the freewheel assembly is designed as a sliding coupling that transmits only compressive forces between the closing spring and the piston assembly. For the freewheel function to function, there must be no rigid connection between the closing spring and the piston assembly. Therefore, a sliding connection that transmits only compressive forces is preferred.

[0016] In a preferred embodiment, a first hydraulic line, in particular a pressure line P, leads from the locking chamber to the solenoid directional control valve, a second hydraulic line, in particular a working line A, leads from the closing damping chamber to the solenoid directional control valve, and a third hydraulic line, in particular a tank line T, leads from the solenoid directional control valve to a tank chamber. The hydraulic lines preferably extend substantially parallel to the longitudinal axis of the door closer and are integrated into the housing of the door closer.

[0017] In an advantageous embodiment, an opening damping chamber is formed between the piston assembly and the partition and / or between the piston assembly and the auxiliary piston. A first throttled connection is located between the opening damping chamber and the tank compartment. The auxiliary piston may be open or need not be sealed within the door closer housing, so that the opening damping chamber extends to the spaces between the piston assembly and the auxiliary piston, and between the auxiliary piston and the partition. When the door is opened, the piston assembly displaces hydraulic oil from the opening damping chamber. The hydraulic oil flows into the tank compartment via the first throttled connection, and in particular via the third line.

[0018] In a preferred embodiment of the opening damping chamber, a first unthrottled connection is provided between the opening damping chamber and the tank chamber. The first throttled connection is always open, and the first unthrottled connection is either closed or open by the piston assembly depending on its position. The first unthrottled connection preferably enters the opening damping chamber between the first throttled connection and the output shaft. This allows the hydraulic oil to flow into the tank chamber via the first unthrottled connection at the beginning of the door opening process. Consequently, the door opens very easily and without resistance at the start of the opening process. Once a certain opening angle is reached, the piston assembly, particularly the opening piston, closes the first unthrottled connection.As a result, the hydraulic oil can only flow into the tank room via the first throttled connection, and the door is dampened shortly before reaching its final position when opening.

[0019] Preferably, the door closer includes a further throttled connection, which is arranged between the closing damping chamber and the tank chamber, particularly in the third line. This further throttled connection serves to dampen the door in the closing direction.

[0020] In a preferred embodiment, the solenoid valve, in its first switching position, connects the first line to the third line and blocks the second line. In its second switching position, the second line is connected to the third line and the first line is blocked. Thus, in the first switching position, the pressure line P, and therefore the sealing chamber, is connected to the tank line T. The working line A, and therefore the closing damping chamber, is blocked. In this switching position, the closing spring or the closing spring tensioning piston is not blocked, and the freewheel function is deactivated. By blocking the working line A, hydraulic oil from the closing damping chamber can only flow into the tank chamber via the further restricted connection, and the closing action of the door is therefore always dampened.In the second switching position, the pressure line P of the locking chamber is blocked, and the working line A of the closing damping chamber is connected to the tank line. This hydraulically locks the closing spring and activates the freewheel function. In this switching position, the closing spring cannot transmit any force to the piston assembly. Simultaneously, the closing damping is deactivated, allowing the piston assembly to move freely and the door to be opened with minimal effort. This design of the hydraulic control is the preferred embodiment.

[0021] In an alternative hydraulic control system, the solenoid valve connects the first line to the second line in its first switching position, and in its second switching position, it connects the second line to the third line and blocks the first line. In the first switching position, the pressure line P of the locking chamber is thus connected to the working line A of the closing damping chamber. In this switching position, the closing spring relaxes and displaces the hydraulic oil from the locking chamber. This first switching position brings the pressure level of the locking chamber to the same level as that of the closing damping chamber. This addition of the displaced oil volumes achieves a highly reliable regulation of the closing speed. The oil from both chambers, the locking chamber and the closing damping chamber, flows together into the tank chamber via the further throttled connection of the closing damping chamber.In the second switching position, the pressure line P of the locking chamber is blocked, thus reactivating the freewheel function. The working line A of the closing damping chamber is connected to the tank line, thus deactivating the closing damping in freewheel mode.

[0022] In an advantageous embodiment, the solenoid valve releases the closing spring when de-energized and allows it to freewheel when energized. This fail-safe principle ensures that in the event of a power failure, the door closes using the energy stored in the closing spring.

[0023] The invention will be explained in more detail below with reference to the accompanying drawing. This shows: Fig. 1 a door closer according to the invention according to a first embodiment, Fig. 2 a door closer according to the invention in the closed door position at 0° opening angle with inactive freewheel for all embodiments, Fig. 3 a door closer according to the invention in the open position at an opening angle of 150° with inactive freewheel for all embodiments, Fig. 4 a door closer according to the invention in the closed door position at 0° opening angle with activated freewheel for all embodiments, Fig. 5 a door closer according to the invention during the opening process with activated freewheel for all embodiments, Fig. 6 a detailed view of the freewheel according to the first embodiment, Fig. 7 a door closer according to the invention in a second embodiment with inactive freewheel, Fig. 8 the door closer according to the invention according to the second embodiment with activated freewheel, Fig. 9 a piston assembly of a door closer according to a third embodiment according to the invention, Fig. 10 different sectional views of the piston assembly according to the third embodiment, Fig. 11 a hydraulic switching symbol for a solenoid directional control valve of a door closer according to a fourth embodiment according to the invention, Fig. 12 a hydraulic switching symbol for a solenoid directional control valve of a door closer according to a fifth embodiment according to the invention, Fig. 13 a hydraulic switching symbol for a solenoid directional control valve of a door closer according to a sixth embodiment according to the invention, Fig. 14 the hydraulic 3 / 2 solenoid directional control valve of the door closer according to the fifth embodiment in the de-energized position, Fig. 15 the hydraulic 3 / 2-way directional control valve of the door closer according to the fifth embodiment in the energized position, Fig. 16 an excerpt from Fig. 15, Fig. 17 the hydraulic 3 / 2 solenoid directional control valve of the door closer according to the sixth embodiment in the de-energized position, Fig. 18 an excerpt from Fig. 17, and Fig. 19 a door closer according to the invention according to a seventh embodiment.

[0024] The following will be based on Fig. 1 The basic structure, hydraulic control and operation of a door closer 41 according to the first embodiment is explained.

[0025] The door closer 41 extends along a door closer longitudinal axis 62. The door closer 41 comprises a door closer housing 42, which in turn consists of a first door closer housing part 43 and a second door closer housing part 44. In Fig. Figure 1 shows the various hydraulic lines outside the door closer housing 42. This is for clarity only. In the actual design, the hydraulic lines are integrated into the door closer housing 42. The following describes the construction of the door closer 41 along its longitudinal axis 62 from left to right. A first compression spring 45 bears against the door closer housing 42, specifically against an end face of the first door closer housing part 43. The first compression spring 45 exerts pressure on a piston assembly 94. This piston assembly 94 is guided within the door closer housing 42, specifically within the first door closer housing part 43. Opposite the first compression spring 45, a second compression spring 52 engages the piston assembly 94. This second compression spring 52 bears against a partition 53, specifically a housing partition.The partition 53 is located at the interface between the first door closer housing part 43 and the second door closer housing part 44. The partition 53 forms a flange for connecting the two housing parts 43 and 44 and simultaneously seals them from each other. A piston rod 54 extends through the partition 53 along the longitudinal axis 62 of the door closer. The piston rod 54 is guided tightly in the partition 53, in particular by means of a mechanical seal. The piston rod 54 is rigidly connected to a closer spring tension piston 55. This closer spring tension piston 55 is guided in the door closer housing 52, in particular in the second door closer housing part 44. A closer spring 56 is connected to the closer spring tension piston 55. The closing spring 56 is supported on one side against the closing spring tension piston 55 and on the other side against an adjustment unit 57 for the closing spring preload.Following the adjustment unit 57 for the closing spring preload, a 3 / 2 solenoid directional control valve 1, designed as a cartridge valve, is integrated in the door closer housing 42, in particular in the second door closer housing part 44.

[0026] The piston assembly 59 comprises a damping piston 46 on its side facing the first compression spring 45 and an opening piston 51 on its side facing the piston rod 54. The damping piston 46 includes a first cam roller 47 rotatably mounted within it. The opening piston 51 includes a second cam roller 50 rotatably mounted within it. An output shaft 48, designed as a camshaft, is arranged between the first cam roller 47 and the second cam roller 50. The output shaft 48 extends along an output axis 85 perpendicular to the longitudinal axis 62 of the door closer. This output shaft 48 transmits the force from the piston assembly 94 to the door and from the door to the piston assembly 94. For this purpose, the output shaft 48 includes a cam-shaped rolling contour 49. The first cam roller 47 and the second cam roller 50 roll on this rolling contour 49. The rolling contour 49 is heart-shaped.

[0027] The damping piston 46, the opening piston 51, and the closing spring tension piston 55 are tightly guided within the door closer housing 42 and preferably include seals or sealing flanges on their circumference for this purpose. This tight guidance of the pistons creates various spaces or chambers within the door closer housing 42, which are interconnected via various hydraulic lines. These chambers or spaces are in turn configured according to the [reference to be added]. Fig. The assembly shown in Figure 1 is presented from left to right along the longitudinal axis 62 of the door closer: A closing damping chamber 58 is formed, defined by the left end face of the door closer housing 42, in particular the first door closer housing part 43, and the damping piston 46. A piston assembly interior 59 is located between the damping piston 46 and the opening piston 51. This can also be referred to as the camshaft chamber. The piston assembly interior 59 is sealed on both sides by the damping piston 46 and the opening piston 51 and is always at tank pressure level. Between the opening piston 51 and the partition 53 is an opening damping chamber 60. On the other side of the partition 53, between the partition 53 and the closing spring tension piston 55, is the locking chamber 61. The locking chamber 61 is defined by the partition 53, the wall of the second door closer housing part 44, and the closing spring tension piston 55.Furthermore, the door closer 41 includes a reservoir 31. The reservoir 31 is located, for example, in the adjustment unit 57 for the closer spring preload. Based on the . Fig. Figures 11 to 18 will later describe a detailed design of the solenoid directional control valve 1. The specific design of a preferred tank chamber 31 will also be described. In particular, a closing spring receiving chamber 92 and / or the piston assembly interior 59 can also be used as a tank by means of unthrottled connections to the tank chamber 31.

[0028] The door closer 41 further comprises a first hydraulic line, designed as a pressure line P, a second hydraulic line, designed as a working line A, and a third hydraulic line, designed as a reservoir line T. The three hydraulic lines run parallel to the longitudinal axis 62 of the door closer within the door closer housing 42. The three hydraulic lines are connected to the various chambers or spaces within the door closer 41 via short channels running radially or perpendicularly to the longitudinal axis 62 of the door closer. Fig. Figure 1 shows the hydraulic lines only schematically. In reality, the hydraulic lines are integrated into the door closer housing 42. The pressure line P runs directly and without restriction from the locking chamber 61 to the solenoid directional control valve 1. The working line A runs directly and without restriction from the closing damping chamber 58 to the solenoid directional control valve 1. The solenoid directional control valve 1 is also connected to the tank line T. The description as "direct and without restriction" means that no separate restrictors are provided in the lines. Nevertheless, the pressure may be slightly restricted by any filters or dynamic pressure differentials.

[0029] The opening damping chamber 60 is connected to the tank line T via a first throttled connection 78. A first throttle valve 65 is used for this purpose. Furthermore, there is a first unthrottled connection 77 between the opening damping chamber 60 and the tank line T. The opening of the opening damping chamber 60 into the first unthrottled connection 77 is located closer to the output shaft 48 than the opening of the opening damping chamber 60 into the first throttled connection 78. This allows the unthrottled connection 77 to be closed by the opening piston 51 after a certain opening angle of the door.

[0030] The closing damping chamber 58 is connected to the tank line T via a second throttled connection 75, which is attached to the front face of the first door closer housing part 43. A second throttle valve 63 is used for this purpose. Furthermore, a third throttled connection 46 is located in the outer surface of the door closer housing 42 between the closing damping chamber 58 and the tank line T, with a third throttle valve 64. The piston assembly interior 59 is connected to the tank line T without any throttle via at least one radial channel. A filter 31 is shown in the tank line T. The position of the filter 31 shown here is purely exemplary. For example, the filter 31 could also be integrated into the solenoid valve 1. Preferably, additional filters 31 could also be located in the other hydraulic lines.

[0031] A first check valve 66 is installed in the damping piston 46. This valve blocks flow towards the interior of the piston assembly 59. A second check valve 67 is installed in the closing piston 51. This valve also blocks flow towards the interior of the piston assembly 59. A third check valve 68 is provided in the closing spring tensioning piston 55. This valve allows hydraulic flow towards the sealing chamber 61. A fourth check valve 69 is provided between the tank chamber 31 and the tank line T. This check valve is spring-loaded and blocks flow towards the tank line T. The first, second, and third check valves 66, 67, and 68 ensure that the closing damping chamber 58, the opening damping chamber 60, and the sealing chamber 61 can always fill with hydraulic oil from the tank volume during expansion.

[0032] A freewheel arrangement is formed between the piston rod 54 and the opening piston 51. The design of this freewheel arrangement is described in Fig. 6 explained in more detail. First, however, the following will be used as an example. Fig. Sections 2 to 5 explain the function and movement sequence of the door closer 41 in more detail. The function and movement sequence of the door closer 41 according to the Fig. Points 2 to 5 apply to all the examples presented here. Fig. Figure 2 shows the door closer 41 at a 0° angle position with the closer spring relaxed. Fig. Figure 2 thus shows the starting position of the door closer 41. Fig. Figure 3 shows the door closer during the opening process at an angle of 150°. The door is opened by a person. This causes the output shaft 48 to rotate. The force is transmitted via the rolling contour 49 to the cam rollers 47, 50. This causes a translational movement of the piston assembly 94 to the right. The piston rod 54, and thus the closer spring tension piston 55, is also moved to the right by the piston assembly 94. This pre-tensions the closer spring 56. During this opening process, the pressure line P is closed by means of the solenoid valve 1. Hydraulic fluid is forced into the locking chamber 61 via the third check valve 68. The Fig. The opening process shown in Figure 3 serves to tension the closing spring 56. After tensioning the closing spring 56 and while keeping the pressure line P closed, the free-running function of the door closer 41 is active. Fig. Figure 4 shows the door closer 41 in the closed position with a door angle of 0°. As can be clearly seen here, the closer spring 56 remains in the tensioned position because the locking chamber 61 remains filled with hydraulic oil. Together with the closer spring tensioning piston 55, the piston rod 54 also remains stationary. Thanks to the freewheel arrangement, the piston assembly 94 lifts off the piston rod 54. The piston assembly 94 is freely movable here, along with the door. Only a slight force is transmitted to the piston assembly 94 via the two compression springs 45 and 52. Fig. As shown in Figure 5, the closing spring 56 remains in its tensioned and locked position during the free-running function. The door is free to move during this time.

[0033] Fig. Figure 6 shows a detailed view of the freewheel according to the first embodiment. The freewheel assembly is designed here as a sliding coupling. The two essential components of this freewheel assembly are the first end face 74 and the second end face 72. The first end face 74 is parallel to the second end face 72. Both end faces 74, 72 are perpendicular to the longitudinal axis 62 of the door closer. The first end face 74 is an end face of the piston rod 54. The second end face 72 is located on the piston assembly 94, in particular on the opening piston 71. In the Fig. In the embodiment shown in Figure 6, a pocket 71 is incorporated into the opening piston 51. Part of the piston rod 54 engages in this pocket 71 and is guided therein along the piston guide 73. The second end face 72 forms the base of the pocket 71. The two end faces 74 and 72 thus face each other within the pocket 71 and can separate from each other in the event of free play.

[0034] The Fig. 7 and Fig. Figure 8 shows a door closer 41 according to a second embodiment. Identical or functionally equivalent components are designated with the same reference numerals in all embodiments. Fig. Figure 7 shows a door closer 41 during the pre-tensioning of the closer spring 56. Fig. 8 The locking chamber 61 is hydraulically blocked via the pressure line P. This keeps the closing spring tensioning piston 55 and the closing spring 56 in a tensioned position. The piston assembly 94 and the door are free to move.

[0035] The second embodiment corresponds to the first embodiment except for the differences described below: In contrast to the first embodiment, in the second embodiment an additional piston 95 is arranged between the partition 53 and the piston assembly 94, in particular the opening piston 51. The additional piston 95 is rigidly connected to the piston rod 54 for the transmission of translational movement. The first end face 74 is formed on the end face of the additional piston 95. The additional piston 95 includes a passage so that both the space between the additional piston 95 and the piston assembly 94 and the space between the additional piston 95 and the partition 53 form the opening damping chamber 60. Another difference between the first and second embodiments is that in the second embodiment the piston rod 54 is pivotably connected to the additional piston 95 and the closing spring tensioning piston 55.The connection between the piston rod 54 and the auxiliary piston 95 is pivotable about a first axis 79. The connection between the piston rod 54 and the closing spring tension piston 55 is pivotable about a second axis 80. Both axes 79 and 80 are perpendicular to the longitudinal axis 62 of the door closer. Furthermore, the first axis 79 is perpendicular to the second axis 80. This pivotable connection of the piston rod 54 prevents the assembly from jamming when forces occur that are not parallel to the longitudinal axis 62 of the door closer.

[0036] The Fig. 9 and Fig. Figure 10 shows a piston assembly 94 of the door closer 41 according to a third embodiment. Identical or functionally equivalent components are designated with the same reference numerals in all embodiments. The piston assembly 94 from the third embodiment can preferably be used in the door closers 41 according to all embodiments presented here.

[0037] The in the Fig. 9 and Fig. The presented piston assembly 94 replaces the piston assembly 94 from the Fig. 1 to 7, in particular the damping piston 46 with the first cam disk 47 and the opening piston 51 with the second cam disk 50. The output shaft 48 remains unchanged. By using the piston assembly 94 according to the third embodiment, the first compression spring 45 and the second compression spring 52 are no longer necessary, but can still be used additionally.

[0038] Fig. Figure 9 shows the piston assembly 94, in which the damping piston 46 and the opening piston 51 are connected to each other by means of a first pull rod 81, a second pull rod 82, a third pull rod 83, and a fourth pull rod 84. The four pull rods 81-84 are arranged parallel to the longitudinal axis 62 of the door closer. Furthermore, the four pull rods 81-84 are located at four corners of a square, which is shown purely for illustrative purposes. The output axis 85 of the output shaft 48 runs through the intersection of the diagonals of this square. This specific arrangement of the four pull rods 81-84 allows the full height 91 (see Figure 9) to be reached. Fig. 10) The rolling contour 49 is positioned between the two upper tie rods 81, 82 and the two lower tie rods 83, 84. The height 91 of the rolling contour 49 is defined in the direction of the output axis 85. The rolling contour 49 does not require any recesses for the tie rods 81-84 and can therefore be optimally loaded.

[0039] The four tie rods 81-84 are each firmly connected to the opening piston 51 via screw connections 87. At their other ends, the four tie rods 81-84 each protrude into through-holes in the damping piston 46. Here, the ends of the tie rods 81-84 are each screwed to a spring clamp nut 88. The first tie rod 81 and the third tie rod 83, which is arranged diagonally to the first tie rod 81, are each under tension with an integrated backlash compensating spring 86. The integrated backlash compensating springs 86 are located on the first tie rod 81 and the third tie rod 83, respectively, and are situated in the damping piston 46. A first end of the backlash compensating springs 86, facing away from the output shaft 48, rests against the spring clamp nut 88, which is screwed to the corresponding tie rod 81, 83. A second end of the respective backlash compensation spring 86, facing the output shaft 48, rests against a shoulder 93 (see Fig. 10), formed in the damping piston 46. Through this special arrangement, the play compensation springs 86, which are designed as compression springs, can subject the first and third tie rods 81, 83 to tensile stress.

[0040] Furthermore, it shows Fig. 9 a first sealing flange 89 on the damping piston 46, which seals the damping piston 46 against the door closer housing 42. In a similar manner, the opening piston 51 is sealed against the door closer housing 42 by means of a second sealing flange 90. These two sealing flanges 89, 90 are used in the piston assemblies 94 of all embodiments.

[0041] Fig. Figure 10 shows three sectional views of the piston assembly 94 according to the third embodiment. Section BB shows that the pocket 71 is again formed in the opening piston 51. The second end face 72 is located at the bottom of this pocket. The piston rod 54 engages in this pocket 71, thus ensuring the freewheel function.

[0042] The embodiments presented so far demonstrate two basic methods for compensating for play between the cam rollers 47, 50 and the rolling contour 49. In the first two embodiments, the damping piston 46 is slightly compressed towards the output shaft 48 by the first compression spring 45. The opening piston 51 is slightly compressed towards the output shaft 48 by the second compression spring 52. This ensures constant contact between the cam rollers 47, 50 and the rolling contour 49. An alternative is shown in the third embodiment. Here, the play compensation is integrated into the piston assembly 94. By means of the tie rods 81-84 and the integrated play compensation springs 89, the damping piston 46 and the opening piston 51 are always slightly drawn together, so that the two cam rollers 47, 50 are always in contact with the rolling contour 49.A particular advantage here is that no torque acts on the piston assembly 94, and thus the door remains in any position during free-running operation. The symmetrical and diagonal arrangement of the four pull rods 81-84 ensures absolutely uniform force transmission and thus prevents any tilting. Therefore, the two backlash-compensating springs 46 are also arranged on two diagonally opposite pull rods 81, 83. Alternatively, a backlash-compensating spring 86 could be provided on each of the pull rods 81-84. Of course, the backlash-compensating springs 86 can preferably be arranged all or some of them in the opening piston 51. Furthermore, the pull rods 81-84 prevent the damping piston 46 and the opening piston 51 from rotating relative to each other.

[0043] Furthermore, the piston assembly 94 according to the third embodiment can also be preferably used together with the first compression spring 45 and / or the second compression spring 52. A special application arises, for example, with very heavy fire doors. The closing force required in the event of a fire necessitates very strong closer springs 56. Thus, for everyday use of the door, it is desirable that the closer spring 56 remains pre-tensioned at all times and, for example, closes the door in the event of a fire. Nevertheless, there is a need for a smooth-running and self-closing door, whereby this smooth closing should occur after every use. Therefore, it is preferred that in each of the door closers 41 presented here, the second compression spring 52 is designed as an "additional closer spring," designed according to EN1 or EN2, whereby this additional closer spring or second compression spring 52 is much weaker than the closer spring 56.In this embodiment, the second compression spring 52 thus always applies a slight closing force to the piston assembly 94, particularly the opening piston 51, even during free-running operation and with the closing spring 56 blocked, so that the door closes automatically even during free-running operation, at least with minimal resistance. Despite this, the user does not need to compress the large closing spring 56 with each opening operation, but only the very lightly designed second compression spring 52. Particularly in this embodiment, the piston assembly 94 can preferably be arranged according to the... Fig. 9 and Fig. 10 according to the third embodiment, combined with the second compression spring 52.

[0044] The Fig. 11, Fig. 12, and Fig. Figures 13 show a fourth, fifth and sixth embodiment of a door closer 41, in each case showing the switching symbol for the solenoid directional control valve 1. Fig. Figure 12, with the fifth initial example, shows the preferred implementation variant.

[0045] The fourth embodiment according to Fig. Figure 11 shows a very simple design, in which the working line A to the closing damping chamber 58 is omitted in such a door closer 41. The solenoid valve 1 here only controls a connection of the pressure line P from the locking chamber 61 to the tank line T. The pressure line P can be either open or closed, so that the freewheel is selectively deactivated or activated.

[0046] Fig. Figure 12 shows the circuit symbol for the fifth embodiment. Here, in the de-energized state of the solenoid directional control valve 1 (shown on the left), the pressure line P is connected to the tank line T. The working line A is closed. The switching position shown on the right indicates the energized state of the solenoid directional control valve 1. Here, the pressure line P, and thus the sealing chamber 61 and consequently also the closing spring 56, are closed. The closing damping chamber 58 is short-circuited to the tank via the working line A.

[0047] Fig. Figure 13 shows the circuit symbol for the sixth embodiment. According to the left-hand illustration, in the de-energized state, the pressure line P is connected to the working line A. In the energized state, according to the right-hand illustration, the pressure line P and thus the barrier chamber 61 are blocked. The working line A and consequently the closing damping chamber 58 are short-circuited to the tank line T.

[0048] The Fig. Figures 14 to 16 now show the constructive design of the magnetic directional control valve 1 according to the door closer 41 from the fifth initial example. Subsequently, based on the Fig. 17 and Fig. 18 a constructive embodiment of the magnetic directional control valve 1 for a door closer 41 according to the sixth embodiment is presented.

[0049] Based on the Fig. 14 the switching position according to Fig. 12 shown on the left. Fig. 15 and Fig. Figure 16 shows the switch position according to the symbol shown on the right. Fig. 12.

[0050] Fig. Figure 14 shows a section through the hydraulic 3 / 2 solenoid directional control valve in the de-energized state. The hydraulic 3 / 2 solenoid directional control valve 1 comprises a valve body 2, a valve chamber 3 integrated into the valve body 2, an electromagnet 4, and a valve plunger 5. The valve plunger 5 moves longitudinally along a valve axis 38.

[0051] Valve chamber 3 comprises a first valve seat bore 6 connecting the pressure line P to valve chamber 3 and a second valve seat bore 7 connecting the working line A to valve chamber 3. Furthermore, a free opening 8 to the tank line T is formed in valve chamber 3. The first valve seat bore 6 is directly opposite the second valve seat bore 7. The free opening 8 is also designed as a bore, with the bore of the free opening 8 being perpendicular to both the first valve seat bore 6 and the second valve seat bore 7. Moreover, the diameter of the first valve seat bore 6 is significantly smaller than the diameter of the second valve seat bore 7.

[0052] The valve tappet 5 is constructed in two parts and comprises a first part 12 and a second part 13 which is screwed into the first part 12 and thus firmly connected to it. The second part 13 extends from the interior of the valve chamber 3 through the second valve seat bore 7 towards the electromagnet 4. The first part 12 lies completely outside the valve chamber 3.

[0053] The second part 13 of the valve tappet 5 comprises on its side facing the first valve seat bore 6 a first sealing surface, designed as a convex surface 9 (see in particular Fig. 16). This convex surface 9 is formed by a sphere 10. The sphere 10, in turn, is embedded in a recess on the end face of the valve tappet 5, in particular the second part 13. Furthermore, a shoulder is formed on the valve tappet 5, in particular on the second part 13. A valve compression spring 14 bears against this shoulder. The convex surface 9 is located within this valve compression spring 14. The valve compression spring 14 also bears against the end face of the first valve seat bore 6. This end face can also be referred to as the sealing surface or side surface of the first valve seat bore 6. Due to this arrangement of the valve compression spring 14, the valve tappet 5 is biased in the direction of the electromagnet 4. In the de-energized state, this leads to the opening of the first valve seat bore 6.

[0054] At the second valve seat bore 7, the valve tappet 5, in particular the second part 13, encompasses a second sealing surface within the valve chamber 3, designed as a conical annular surface 11. This conical annular surface 11 extends around the entire circumference of the valve tappet 5. When the electromagnet 4 is de-energized, this conical annular surface 11 is pressed against the second valve seat bore 7 and thus seals the working line A against the valve chamber 3.

[0055] The electromagnet 4 comprises a coil 16, an armature 17, and a pole piece 18. The coil 16 is wound around the armature 17 and the pole piece 18. The armature 17 and the pole piece 18 are arranged one behind the other along the longitudinal axis 38 of the valve. A bore is located in the pole piece 18 along the longitudinal axis 38 of the valve. This bore forms a linear guide 19 for at least a portion of the valve tappet 5, in particular a portion of the first part 12 of the valve tappet 5. When energized, there is a gap 20 between the pole piece 18 and the armature 17 that is as small as possible. When de-energized, the gap 20 is larger. The electromagnet 4 also includes a connecting cable or power supply 21 for connecting a control unit to the hydraulic 3 / 2-way solenoid directional control valve 1. The armature 17 and the pole piece 18 are embedded in a sleeve 23. Furthermore, there is an insulation 24 between the sleeve 23 and the coil 16.

[0056] The pole core 18 and the armature 17 are located in a so-called armature chamber 22. This armature chamber 22 is located inside the sleeve 23. The working line A is sealed against this armature chamber 22 by a special seal, in particular a U-ring seal 25. This U-ring seal 25 is located between the valve tappet 5, in particular the first part 12, and the pole core 18. A connecting channel 15 runs inside the valve tappet 5. This connecting channel 15 connects the armature chamber 22 to the valve chamber 3. Since the valve chamber 3 is always freely connected to the tank line T, the armature chamber 22 is also always depressurized. The connecting channel 15 is formed by a longitudinal bore along the valve axis 38 in the valve tappet 5 and by bores perpendicular to the valve axis 38 from the surface of the valve tappet 5 to the longitudinal bore.In particular, the two-part design of the valve tappet 5 allows the longitudinal bore along the valve longitudinal axis 38 to be produced inside the valve tappet 5.

[0057] The valve housing 2 comprises a base housing part 26, a first valve chamber insert 27, and a second valve chamber insert 28. The first valve chamber insert 27 and the second valve chamber insert 28 together form the valve chamber 3. The hydraulic 3 / 2 solenoid directional control valve 1 is constructed and assembled as follows: An annular extension 29 is located on the electromagnet 4. Part of the second valve chamber insert 28 is embedded in this extension 29. The second valve chamber insert 28, in turn, accommodates the first valve chamber insert 27. The previously mentioned sleeve 23 of the electromagnet 4 extends to the second valve chamber insert 28 and is connected to it. The complete unit, consisting of the electromagnet 4, the second valve chamber insert 28, and the first valve chamber insert 27, is screwed into the base housing part 26.For this purpose, an internal thread is formed on the base housing part 26 and a corresponding external thread is formed on the extension 29 of the electromagnet 4. The individual housing components are sealed against each other.

[0058] Furthermore, the housing 2 includes a cap 30. This cap 30 surrounds the electromagnet 4 and sits on the base housing part 26.

[0059] A drilled insert 35 is located within the first valve chamber insert 27. The first valve seat bore 6 is formed in this drilled insert 35. Furthermore, a filter 36 is located within the first valve chamber insert 27. This filter 36 is situated outside the valve chamber 3 and in the pressure line P.

[0060] Furthermore, a volume compensation unit 37 with a tank chamber 31 is integrated within the base housing part 26. This volume compensation unit 37 with tank chamber 31 comprises a volume compensation piston 32, a compensating spring or length compensation spring 33, and a bearing 35 for the compensating spring 33. The tank chamber 31 is connected to the tank line T. The volume compensation piston 32 defines a wall of the tank chamber 31. The piston 32 is slightly spring-loaded by the compensating spring 33. The compensating spring 33 is supported on one side against the volume compensation piston 32 and on the other side against the spring bearing 34. The spring bearing 34 is screwed into the end face of the base housing part 26.

[0061] The hydraulic 3 / 2 solenoid directional control valve 1 is largely rotationally symmetrical with respect to the valve's longitudinal axis 38. The pressure lines P, working lines A, and tank lines T naturally deviate from this rotational symmetry. The pressure line P and the working line A each terminate at at least one point on the outer surface of the base housing part 26. Annular channels 39 are provided at these points. These annular channels 39 are sealed with O-ring seals 40 when the cartridge-type 3 / 2 solenoid directional control valve 1 is inserted into a corresponding receptacle.

[0062] Fig. Figure 15 shows the hydraulic 3 / 2-way solenoid directional control valve 1 according to the exemplary embodiment in the energized state. Here it can be clearly seen that the valve plunger 5 differs from the illustration in Fig. The valve seat 14 was moved to the left. As a result, the working line A is directly connected to the valve chamber 3, and thus to the tank line T and the tank space 31, via the second valve seat bore 7. The pressure line P is blocked by the seat of the ball 10 in the first valve seat bore 6 and is therefore not connected to the valve chamber 3.

[0063] Fig. 16 shows a detail from Fig. 15. This illustration can be used to explain the difference area ratio in particular. It should be noted that this difference area ratio applies when the second valve seat bore 7 is closed, and thus when the... Fig. The unpowered valve position shown in section 14 is used. How the Fig. As shown in Figure 16, the valve tappet 5 has a sealing diameter D1 at the O-ring seal 25. The second valve seat bore 7 has an inner diameter D2. The valve tappet 5 has a minimum diameter D3 in the area between the O-ring seal 25 and the second valve seat bore 7. When the second valve seat bore 7 is closed, the pressure in the working line A acts on the following surfaces of the valve tappet 5: The first surface is calculated by (D2 2 / 4*π) - (D3 2 / 4*π). The second area is calculated by (D1 2 / 4*π) - (D3 2 / 4*π). Because the first area is smaller than the second area, the working pressure acts to the right in the illustration when the second valve seat bore 7 is closed. This supports the valve pressure spring 14 and draws the conical surface 11 into the second valve seat bore 7.

[0064] The fifth embodiment demonstrates how a hydraulic 3 / 2-way solenoid directional control valve 1, particularly in cartridge design, can be implemented for leak-free operation. In the de-energized switching position, shown in Fig. 14, the valve tappet 5 is pressed by the compression spring 14 with its conical surface 11 into the second valve seat bore 7 of the working line, thus sealing off the connection of this line to the tank in an oil-tight manner. The valve tappet 5 is radially fitted with a grooved seal 25 on the magnet side facing the armature chamber 22. The sealing diameter D1 of the valve tappet 5 to the armature chamber 22 is larger than the second valve seat bore 7. This creates a defined area ratio between the conical seat and the sealing diameter D1 of the armature chamber 22. When the working line A is pressurized, a differential force arises due to the area ratio between the working line and the sealed armature chamber 22, which pulls the valve tappet 5 towards the electromagnet 4 and, in addition to the spring force, acts against the second valve seat bore 7. The sealing effect increases with increasing pressure in the working line A.The electromagnet 4 is preferably designed such that switching against the spring force plus differential force is prevented. The pressure line P and the tank line T are connected to each other in this position.

[0065] In the energized switching position according to Fig. In position 15, the working line A is depressurized, with the valve plunger 5 sealing the pressure line P oil-tight against the spring force with its ball 10. A consumer connected via the pressure line P, e.g., the sealing chamber 61, can now be effectively sealed up to the designed operating pressure. This operating pressure depends on the magnetic force. In this switching position, the working line A is depressurized and connected to the tank line T. Therefore, no pressure, or only a low back pressure, can build up in the working line A.

[0066] The embodiments of the presented 3 / 2-way solenoid directional control valve are, regardless of the cartridge design and regardless of the number of lines and / or switching positions, also applicable to other valve designs according to the invention. In particular, the combination of a ball seat and a cone seat in a valve, especially on a plunger, and / or the differential area ratio are applicable to other valves according to the invention.

[0067] Based on the Fig. 17 and Fig. Section 18 now explains in more detail the constructive design of the magnetic directional control valve 1 of the door closer according to the sixth embodiment. Both figures show the de-energized switching position with open pressure line P, as described in Fig. Figure 13 on the left is shown symbolically. Identical or functionally equivalent components are designated with the same reference numerals in all embodiments. In particular, the solenoid directional control valve 1, as used in the sixth embodiment, corresponds to the solenoid directional control valve 1, as used in the fifth embodiment, except for the differences described below.

[0068] As the Fig. 17 and Fig. As shown in Figure 18, in the sixth embodiment, the tank line T and the working line A are interchanged compared to the fifth embodiment. This means that the working line is always connected to the valve chamber 3 via the free opening 8. The connection between the valve chamber 3 and the tank line T is controlled via the second valve seat bore 7 and the conical ring surface 11. Furthermore, the valve plunger 5 is a single piece in the sixth embodiment. In addition, the path for pressure equalization between the armature chamber 22 and the tank line T in the solenoid valve 1 is shorter according to the sixth embodiment. Here, the connection 15 is designed as a simple, flat surface between the armature chamber 22 and the tank line T. No bores in the valve plunger 5 are required. The connection 15 is designed as a flat surface on the valve plunger 5 or by forming the valve plunger 5 as a polygon.

[0069] Furthermore, the valve housing 2 in the solenoid valve 1 is of a somewhat simpler design according to embodiment 6. The valve chamber 3 is no longer constructed in two parts with a first valve chamber insert 27 and a second valve chamber insert 28. Instead, only one valve chamber insert 27 is used.

[0070] The solenoid valves according to the fourth, fifth and sixth embodiments of the door closer 41 can preferably be used in all embodiments of the door closer 41 presented here.

[0071] Fig. Figure 19 shows a door closer according to a seventh embodiment. Identical or functionally identical components are designated with the same reference numerals in all embodiments. The arrangement presented in the seventh embodiment for preventing the so-called springback of the closer spring tension piston 55 can preferably be applied in all embodiments of the door closer 41 presented here.

[0072] Fig. Figure 19 shows the third check valve 68 in the closer spring tension piston 55 as a spring-loaded check valve. The space within the door closer housing 42, in particular within the second door closer housing part 44, in which the closer spring 56 is located, is referred to here as the closer spring receiving space 92. This closer spring receiving space 92 is a space that shrinks during the opening process of the door, as the closer spring tension piston 55 moves to the right. Furthermore, Figure 19 shows... Fig. 19 The fourth check valve 69 is also a spring-loaded check valve. The third check valve blocks hydraulic flow from the blocking chamber 61 into the closing spring receiving chamber 92. The fourth check valve blocks hydraulic flow from the closing spring receiving chamber 92 into the tank line T.

[0073] During the pressure build-up in the locking chamber 61, all elastic elements contained therein, such as seals, residual air, or even the hydraulic fluid itself, are compressed accordingly, resulting in an undesirable loss of volume. The spring tension piston 55 compensates for this volume loss, but in doing so, it makes a small subsequent stroke. Ultimately, the closing spring tension piston 55 does not lock precisely at the desired position. The in Fig.The arrangement shown in Figure 19 reduces this springback by pumping pressurized hydraulic oil from the closing spring retainer chamber 92 into the sealing chamber 61 via the third check valve 68 during the opening process. This intentionally creates a relative opening resistance similar to opening damping, pre-pressurizing the hydraulic oil and thus anticipating settling behavior. Thanks to the fourth check valve 69, the hydraulic oil cannot escape from the closing spring retainer chamber 92 towards the tank line T. During the opening process, the hydraulic oil in the closing spring retainer chamber 92 is thus pre-pressurized by the closing spring tensioning piston 55 and flows into the sealing chamber 61 at a certain pre-pressure. This largely prevents the undesired springback.

[0074] Furthermore, the following items and preferred embodiments are provided according to the invention:

[0075] Advantageously, the freewheel assembly is arranged between the piston rod and the piston assembly. Alternatively, and preferably, the freewheel assembly is located in the piston rod or between the piston rod and the closing spring, in particular between the piston rod and the closing spring tensioning piston.

[0076] Furthermore, it is advantageous that the freewheel assembly comprises a first end face perpendicular to a door closer longitudinal axis and rigidly connected to the piston rod, and a second end face parallel to the first end face and rigidly connected to the piston assembly, whereby when the closer spring is blocked, the second end face lifts off the first end face and is thus decoupled. A very simple and effective freewheel assembly as a sliding coupling can be realized by means of two end faces that are in contact and lifting off each other.

[0077] Advantageously, a pocket is formed in the piston assembly, with the piston rod being movably guided in the pocket. Alternatively, the pocket can also be formed, for example, in the spring-loaded piston. In another alternative, the piston rod is designed in two parts, with one part of the piston rod having a pocket opening in the direction of the door closer's longitudinal axis, and the other part of the piston rod being translationally movable within this pocket.

[0078] Advantageously, the door closer includes an additional piston guided within the door closer housing between the piston assembly and the piston rod, and rigidly connected to the piston rod, with the first end face formed on the additional piston. The piston rod and the additional piston are rigidly connected to each other, i.e., they always move together along the longitudinal axis of the door closer.

[0079] In an advantageous embodiment of the auxiliary piston, the connection between the piston rod and the auxiliary piston is designed to pivot about a first axis perpendicular to the longitudinal axis of the door closer. This pivotable design avoids any forces that are not linear with the longitudinal axis of the door closer and could therefore lead to jamming.

[0080] Furthermore, it is advantageously provided that the connection between the piston rod and the closing spring tension piston is pivotable about a second axis perpendicular to the longitudinal axis of the door closer and perpendicular to the first axis. This pivotable connection between the piston rod and the closing spring tension piston also prevents any jamming.

[0081] When the locking chamber is not locked, the closing spring, through its preload force, can exert direct pressure on the piston assembly within the freewheel clutch via the piston rod, or conversely, the piston assembly can exert pressure on the piston rod. In this operating state, the door closer operates normally, with the closing spring being manually tensioned. After the door is released, the closing spring, via the piston assembly and the output shaft, returns the door to its closed position. However, if the closing spring is hydraulically locked, for example by energizing a solenoid valve, the hydraulic oil can no longer drain from the locking chamber. Consequently, after the closing spring has been manually tensioned once, the spring force can no longer act on the piston assembly.When the door is manually opened from the open position back to the closing position, the piston rod lifts off the piston assembly within the freewheel assembly, specifically within the sliding coupling. The piston assembly itself moves, driven by the door and the output shaft, and completes a short stroke. Within the freewheel assembly, a gap corresponding to this stroke is created between the first and second end faces. The return movement of the piston assembly by reopening the door is effortless, corresponding to a freewheel function. Further manual opening and closing movements of the door can be performed as often as desired and effortlessly in freewheel mode, provided the locking mechanism is largely closed. Only after the locking mechanism is released can the closer spring return to its relaxed state.In this free-running arrangement, the first end face is brought back into contact with the second end face, and the force of the closing spring is transferred to the door via the piston assembly and the output shaft. This ensures that the door is securely closed by the stored energy without any additional manual intervention.

[0082] In a preferred embodiment, the output shaft comprises a cam-shaped rolling contour, in particular a cam disc, and the piston assembly includes at least one cam roller bearing against the rolling contour. Door closers with slide rail linkages have become increasingly popular in recent years for aesthetic reasons. To simultaneously achieve comfortable operation, i.e., a decreasing opening resistance or opening torque with increasing door angle, cam technology is preferably employed within the door closer mechanism of the invention to transmit the force between the piston assembly and the output shaft.

[0083] In a preferred embodiment of the piston assembly, the assembly comprises a damping piston with a first cam roller and an opening piston with a second cam roller, with the output shaft arranged between the damping piston and the opening piston. The cam rollers of the damping piston and the opening piston must be in constant contact with the rolling contour and thus roll along the contour when the output shaft rotates. This creates a working stroke for the damping piston and the opening piston. On the longer side of the door closer housing, the closing spring is pre-tensioned via the opening piston and the piston rod. On the opposite side, the hydraulically actuated damping piston is displaced. This displacement of the damping piston displaces hydraulic fluid, which, by means of intermediate throttle valves, allows the door speed during the closing process to be controlled or slowed.In conjunction with the force of the closing spring, a resultant force is generated via the cam geometry of the rolling contour, which, together with the corresponding internal lever arm, produces the opening and closing torque. To design the presented door closer with the narrowest possible profile, the opening piston and the damping piston are preferably arranged in a specific manner: The damping piston is located on one side of the output shaft and the opening piston on the other side, so that the output shaft is positioned between the two pistons. Consequently, direct contact between the opening piston and the damping piston is not possible. This very narrow design of the door closer therefore means that combining the two functions—pre-tensioning the closing spring and damping the closing process—in a single component is not directly feasible.The implementation of the hydraulic "freewheel" function therefore requires complex measures on both sides of the housing, as the functional areas are located separately within the housing. By comparison, wide-profile floor-mounted door closers typically have only one piston on the spring side, which simultaneously handles the closer spring preload and the damping function. However, these closers utilize a so-called cam carriage, which encompasses the cam profile with two rollers mounted within it and ensures constant monitoring of the cam-roller contact. When using this cam carriage, no further considerations are needed to ensure backlash-free contact between the two pistons of the piston assembly and the cam profile. However, such a cam carriage is not feasible with integrated and therefore very narrow door closers like the one presented here.Furthermore, when using cam technology, it should be noted that a disadvantage compared to conventional rack and pinion technologies is the limited stroke and thus volume displacement, coupled with high spring force requirements. Cam door closers therefore require robust bearings and complex hydraulic component arrangements. Two different variants are presented below, which ensure that the two separate pistons, the opening piston and the damping piston, always maintain backlash-free contact with the rolling contour. The first variant uses tie rods and internal backlash-compensating springs. The second variant uses compression springs that act externally on the opening piston and / or damping piston.

[0084] Preferably, the damping piston and the opening piston are connected to each other via tie rods. Since the opening piston and the damping piston are located on both sides of the output shaft, direct contact between the two is not possible. The tie rods enable a connection between the two pistons that is easy to assemble and manufacture. Furthermore, the use of multiple tie rods effectively prevents the two pistons from rotating around the longitudinal axis of the door closer.

[0085] Furthermore, the use of exactly four tie rods is advantageous. The four tie rods can be evenly distributed across the cross-section, thus enabling a uniform force transmission.

[0086] In a particularly preferred embodiment, two of the four pull rods are arranged symmetrically to the longitudinal axis of the door closer. This means that two diagonally opposite pull rods are equidistant from the output shaft. Specifically, the four pull rods are arranged at the corners of a square (presented only as a model). The output shaft runs through the intersection of the diagonals of this square. This arrangement enables a perfectly uniform force transmission between the opening piston and the damping piston, parallel to the longitudinal axis of the door closer, and largely prevents the piston assembly from jamming.

[0087] In a particularly preferred embodiment, two tie rods are arranged above the rolling contour and on both sides of the output shaft, and two further tie rods are arranged below the rolling contour and on both sides of the output shaft, so that the rolling contour, with its full height, is positioned between the two upper tie rods and the two lower tie rods. The tie rods positioned above and below the cam area or the rolling contour ensure that the full load-bearing capacity of the rolling contour is maintained.

[0088] Preferably, the piston assembly comprises at least two integrated backlash-compensating springs, wherein at least two diagonally arranged tie rods are tension-loaded by means of the backlash-compensating springs to compensate for play between the rolling contour and the cam rollers. These two tension-loaded tie rods serve to compensate for play between the cam rollers of the two pistons and the rolling contour, and the two other diagonal rods serve to prevent rotation and thus avoid tilting moments and the associated friction and jamming of the opening piston and damping piston.

[0089] Preferably, the backlash springs are arranged in the damping piston and / or the opening piston. This eliminates the need for external springs acting on the piston assembly to compensate for the backlash between the cam rollers and the rolling contour. Consequently, the piston assembly does not need to be supported against stationary parts of the door closer and can ensure backlash compensation solely through the internal arrangement of the tie rods and backlash springs.

[0090] Preferably, the tie rods extend through the backlash-compensating springs, which are designed as compression springs and press against the ends of the tie rods, thus subjecting the tie rods to tensile stress. The other ends of the backlash-compensating springs bear against the opening piston or the damping piston. The non-spring-loaded ends of the tie rods are screwed firmly into the respective other piston.

[0091] Alternatively or additionally to the use of tie rods and backlash springs, it is preferably provided that a first compression spring is arranged between the damping piston and the door closer housing, wherein the first compression spring is designed to compensate for the backlash between the rolling contour and the first cam roller of the damping piston. This first compression spring exerts a slight force on the damping piston in the direction of the output shaft.

[0092] Furthermore, it is preferably provided that a second compression spring is arranged between the opening piston and the piston rod, or between the opening piston and the auxiliary piston, or between the opening piston and the partition, wherein the second compression spring is designed to compensate for play between the rolling contour and the second cam roller. This second compression spring, similar to the first compression spring, serves to compensate for play between the cam roller and the rolling contour. Preferably, the first compression spring and / or the second compression spring are designed to be so weak that they do not transmit any perceptible torque to the door for the user, but merely compensate for play in the cam mechanism.

[0093] In a preferred embodiment, an additional closing spring is arranged between the piston assembly and the piston rod, or between the piston assembly and the auxiliary piston, or between the piston assembly and the partition, to slightly bias the piston assembly in the closing direction during free movement. This additional closing spring is weaker than the closing spring. The closing spring, which fulfills the fire protection function and is designed to be extremely strong, is preferably tensioned once and then blocked via the locking space until, for example, a fire occurs. However, in everyday use of the door, it is often desirable for the door to close again after being used, although not with the force of a strong closing spring for emergencies. The additional, lighter closing spring serves this purpose. In particular, this additional closing spring is designed according to EN1 or EN2 as per DIN EN1154.A so-called second compression spring for compensating for play between the cam roller of the opening piston and the rolling contour has already been described. This second compression spring is preferably replaced by the additional closing spring. Alternatively, the use of internal piston assembly tie rods and play-compensating springs can also be combined with the additional closing spring.

[0094] Advantageously, a spring-loaded check valve is arranged between the locking chamber and a space that shrinks during the door opening process. This shrinking space is, in particular, the receiving space for the closing spring. The spring-loaded check valve blocks in the direction of the shrinking space. According to the invention, hydraulic pressure is built up and maintained in the locking chamber to lock the closing spring. To build up pressure in the locking chamber, all elastic elements contained therein, such as seals, residual air, or even the hydraulic oil itself, are compressed accordingly. This results in an undesirable loss of volume. Although the closing spring tensioning piston compensates for this volume loss, it makes a small follow-up stroke. This follow-up stroke is transmitted to the piston rod and thus to the piston assembly, the output shaft, and the door.This results in the door rotating back a few degrees when the hold-open function is used. If the free-swing function is used, the subsequent stroke prevents the door from being fully opened to the desired position. This undesirable effect is called springback, which is particularly noticeable when the door opening angle is limited by structural conditions. This effect is especially pronounced in door closers with cam technology due to the small rotation-to-stroke ratio. The arrangement presented here with the spring-loaded check valve reduces this springback by actively pumping pressurized hydraulic oil from a pressure chamber that decreases in size in the opening direction into the locking chamber via the check valve during the opening process.A relative opening resistance, similar to opening damping, is deliberately created to pre-tension the hydraulic oil and anticipate settling behavior. In previously known arrangements, the hydraulic oil is passively drawn from a tank into pressure chambers during the opening process, which can even create a slight vacuum. The elastic elements then fully relax and require a relatively large compensation volume with a corresponding subsequent stroke to generate sufficient holding pressure for the spring force. This results in a maximum pressure differential. In the case described here, the settling behavior of the elastic elements in the locking chamber therefore occurs under a small pressure differential, resulting in a smaller volume loss and thus a shorter subsequent stroke. Consequently, the return rotation or springback of the piston assembly from the intended position is significantly less.

[0095] Preferably, the check valve is arranged such that hydraulic oil in the shrinking space is pressurized by the opening process and is thus actively pumped through the check valve into the sealing chamber.

[0096] Advantageously, the check valve is arranged in the closing spring tension piston.

[0097] Furthermore, it is advantageous that the shrinking space is closed during the opening process, with the exception of the check valve.

[0098] This sealing is achieved in particular by placing an additional check valve between the shrinking chamber and the tank line, with the additional check valve blocking flow towards the tank line. This pre-tensions, for example, hydraulic oil located in the receiving chamber of the closing spring during the opening process, allowing it to be pumped into the sealing chamber via the spring-loaded check valve in the closing spring tensioning piston.

[0099] The invention further comprises a hydraulic solenoid directional control valve, in particular a hydraulic 3 / 2-way solenoid directional control valve, comprising a valve housing, an electromagnet, and a valve plunger. A valve chamber is integrated into the housing. This valve chamber includes a first valve seat bore connecting to a first line, in particular a pressure line, a second valve seat bore connecting to a second line, in particular a working line, and a free opening to a third line, in particular a tank line. The opening is referred to as "free" because it connects the valve chamber to the third line in every switching position of the valve. The valve plunger is at least partially arranged within the valve chamber and is moved linearly by the electromagnet.Furthermore, the valve tappet within the valve chamber comprises a first sealing surface facing the first valve seat bore and a second sealing surface facing the second valve seat bore, allowing either the first or the second valve seat bore to be closed. The valve tappet also extends from the valve chamber through the second valve seat bore and through the second line to the electromagnet. Because the valve tappet extends beyond the valve chamber, it can be connected to the electromagnet or partially integrated into it. When the second valve seat bore is closed, the pressure of the second line, particularly the working line, draws the valve tappet into the second valve seat bore via a differential surface area ratio. This arrangement with the differential surface area ratio promotes a leak-free seal of the second valve seat bore.

[0100] This differential area ratio is achieved in particular by ensuring that the sealing diameter of the valve tappet outside the valve chamber is larger than the diameter of the second valve seat bore. The sealing diameter is defined by a seal between the valve tappet and the electromagnet.

[0101] Preferably, the differential surface area ratio is achieved by making the diameter of the valve tappet outside the valve chamber larger than the bore diameter of the second valve seat bore. This allows the pressure of the second line upstream of the valve chamber, when the second valve seat bore is closed, to assist the force of the compression spring and draw the second sealing surface into the second valve seat bore.

[0102] In a further preferred embodiment, the valve tappet is formed in at least two parts. Here, the valve tappet comprises a first part and a second part, wherein the first part is guided linearly within the electromagnet and the second part is screwed into the first part. This means the second part is rigidly connected to the first part and is linearly movable together with it. This two-part design of the valve tappet is particularly easy to assemble, especially for achieving the differential area ratio. In particular, this allows the sealing diameter to be larger than the bore diameter of the second valve seat bore.

[0103] Furthermore, it is preferably provided that a seal, in particular a U-ring seal, is arranged between the valve tappet and an armature chamber of the electromagnet. This seal is located at the sealing diameter between the valve tappet and the electromagnet, as already discussed. Particularly preferably, the armature chamber is always freely connected to the third line, in particular the tank line, via a connecting channel running through the valve tappet. This prevents pressure build-up in the armature chamber in the event of possible leaks in this U-ring seal. The connecting channel within the valve tappet runs from the armature chamber through the valve tappet into the valve chamber. As already described, the valve chamber is always freely connected to the third line, in particular the tank line.

[0104] As an alternative to the hydraulic solenoid valve described first, the invention comprises a hydraulic solenoid valve, in particular a hydraulic 3 / 2-way solenoid valve, comprising a valve housing, a valve chamber integrated into the valve housing with a first valve seat bore connecting to a first line, in particular a pressure line, a free opening to a second line, in particular a working line, and a second valve seat bore connecting to a third line, in particular a tank line. Furthermore, this hydraulic solenoid directional control valve comprises an electromagnet and a valve plunger movable by the electromagnet and partially arranged in the valve chamber. The valve plunger comprises, within the valve chamber, a first sealing surface facing the first valve seat bore and a second sealing surface facing the second valve seat bore, so that either the first valve seat bore or the second valve seat bore can be selectively closed.Furthermore, the valve tappet extends out of the valve chamber through the second valve seat bore to the electromagnet.

[0105] In a preferred embodiment of the alternative hydraulic solenoid valve, a connection between the third line and an armature chamber of the electromagnet is provided along or within the valve stem, thus preventing pressure build-up in the armature chamber. This connection is achieved, in particular, by providing a flat surface on the valve stem or by manufacturing the valve stem as a polygon, especially a hexagon.

[0106] The following describes advantageous embodiments of the two hydraulic solenoid directional control valves according to the invention: In a preferred embodiment, the diameter of the first valve seat bore is smaller than the diameter of the second valve seat bore. In a preferred embodiment, a compression spring is arranged between the first valve seat bore and the valve tappet. The valve according to the invention can thus, in the variant with a ball, be described as a spring-loaded ball-cone seat valve.

[0107] In a further advantageous embodiment, it is provided that, in the de-energized state of the electromagnet, the second sealing surface, in particular a conical surface, seals the second valve seat bore, and that, in the energized state of the electromagnet, the first sealing surface, in particular a convex surface, seals the first valve seat bore. The preferably provided compression spring serves to press the second sealing surface of the valve tappet into the second valve seat bore in the de-energized state.

[0108] Preferably, the first sealing surface comprises a convex surface, in particular a sphere. More preferably, the second sealing surface comprises a conical surface, in particular a conical ring surface. By linearly displacing or moving the valve stem, either the first valve seat bore with the convex surface or the second valve seat bore with the conical surface is selectively closed. Jamming or sticking in the switching position under pressure is effectively prevented by the ball valve design with the convex surface.

[0109] Furthermore, the invention preferably includes a filter, particularly in the first line. The filter is especially preferably arranged outside the valve chamber directly upstream of the inlet to the first valve seat bore. The filter prevents contamination of the oil and, in particular, contamination of the two valve seats. In another preferred embodiment, the first valve seat bore is located directly opposite the second valve seat bore. In a preferred embodiment, the electromagnet comprises a coil, an armature, a pole piece, and a gap between the pole piece and the armature. The pole piece includes a bore along the longitudinal axis of the valve tappet and thus provides a receptacle and linear guidance for the valve tappet. Furthermore, the solenoid directional control valves according to the invention preferably include a control unit for the electromagnet. This control unit allows the electromagnet to be energized and de-energized.

[0110] Furthermore, the invention comprises a hydraulic cartridge solenoid directional control valve, in particular a hydraulic cartridge 3 / 2 solenoid directional control valve, comprising one of the hydraulic solenoid directional control valves just described, wherein the housing is designed for at least partial insertion into a valve receptacle. This valve receptacle is located in a component that integrally accommodates the cartridge 3 / 2 solenoid directional control valve. Preferably, the first line, in particular the pressure line, and the second line, in particular the working line, are guided radially and perpendicularly outwards with respect to the longitudinal axis of the valve stem, respectively. Furthermore, O-ring seals are preferably located laterally to the surface of the valve housing of the outwardly guided first and second lines, so that these lines can be connected pressure-tight by inserting the cartridge housing. For this purpose, the valve housing particularly preferably includes circumferentially extending annular channels.From these annular channels, several radially directed channels for the first line and / or several radially directed channels for the second line can preferably lead to the valve chamber.

[0111] Furthermore, it is preferred that the hydraulic cartridge solenoid directional control valve includes a volume compensation unit with a reservoir. This volume compensation unit with reservoir is integrated into the valve housing or flanged to the valve housing. The reservoir is preferably connected to the third line. The valve is preferably constructed along the longitudinal axis of the valve stem as follows: The valve chamber with valve stem is arranged centrally. The volume compensation unit with reservoir is integrated or flanged to one side of the chamber. The electromagnet is mounted on the other side of the valve chamber. This allows the hydraulic cartridge solenoid directional control valve to be inserted into a component with the volume compensation unit leading the way. The electromagnet, and in particular a connector on the electromagnet, preferably protrude from the component.In a preferred embodiment, the tank space of the volume compensation unit is slightly pressurized by means of a volume compensation piston and a compensation spring or compression spring.

[0112] Furthermore, the invention comprises a door closer, in particular a swing door closer, with a free-running function, comprising one of the hydraulic solenoid valves described above or one of the hydraulic cartridge solenoid valves, wherein the valve receptacle is formed in the door closer. The hydraulic solenoid valve or cartridge solenoid valve is thus integrated into or flanged to the housing of the door closer and serves to control the hydraulics between the closing damping chamber, the locking chamber and the tank chamber or the tank line.

[0113] The door closer with the hydraulic solenoid valve preferably further comprises a door closer housing, an output shaft connectable to a door, a piston assembly connected to the output shaft and guided in the door closer housing, a closing spring, a piston rod arranged to connect the piston assembly to the closing spring, a freewheel arrangement designed to allow translational movement of the piston assemblies decoupled from the closing spring when the closing spring is blocked, and a hydraulic locking chamber designed to block the closing spring.

[0114] The advantageous embodiments of the door closer according to the invention described above find correspondingly advantageous application to the door closer with the hydraulic solenoid directional control valve or the hydraulic cartridge solenoid directional control valve. Reference symbol list 1 3 / 2-way solenoid directional control valve 2 Valve housings 3 valve chamber 4 Electromagnet 5 valve tappets 6, 7 valve seat bores 8 free opening 9 convex surface 10 balls 11 Conical ring area 12 Part One 13 Part Two 14 Valve pressure spring 15 connection channel 16 coil 17 anchors 18 pole pieces 19 linear guide 20 gaps 21 Connection line 22 Anchor room 23 Sleeve 24 Insulation 25 U-ring seal 26 Base housing part 27 first valve chamber insert 28 second valve chamber insert 29 continuation 30 cap 31 Tank room 32 volume compensation pistons 33 Compensating spring 34 spring bearings 35 drilled insert 36 filters 37 Volume compensation unit 38 Valve longitudinal axis 39 ring channels 40 O-ring seals 41 door closers 42 door closer housings 43 first door closer housing part 44 second door closer housing part 45 first compression spring 46 damping pistons 47 first curve roll 48 Output shaft, designed as a camshaft 49 Rolling contour 50 second curve roll 51 opening pistons 52 second compression spring 53 Housing partition 54 Piston rod 55 Closer spring tension piston 56 closing spring 57 Adjustment unit for the closing spring preload 58 Closing damping room 59 Piston assembly interior, in particular camshaft area 60 Opening damping space 61 Restricted area 62 Door closer longitudinal axis 63 second throttle valve 64 third throttle valve 65 first throttle valve 66 first check valve 67 second check valve 68 third check valve 69 fourth check valve 70 Mechanical seal 71 bags 72 second end face, especially pocket bottom 73 Piston guide 74 first front surface 75 second throttled connection 76 third throttled connection 77 first unthrottled connection 78 first throttled connection 79 first axis 80 second axis 81 first pull rod 82 second pull rod 83 third pull rod 84 fourth pull rod 85 Output axle 86 integrated play-compensating springs 87 Screw connection 88 spring tension nuts 89 first sealing flange 90 second sealing flange 91 Height of the rolling contour 92 Closer spring mounting space Paragraph 93 94 Piston assembly 95 additional pistons P first line, especially pressure line A second line, especially work line Third line, especially tank line

Claims

[1] Door closers (41), in particular swing door closers, comprising a hold-open or free-running function a door closer housing (42), an output shaft (48) that can be connected to a door, a piston assembly (94) connected to the output shaft (48) and guided in the door closer housing (42), a closing spring (56), a piston rod (54) arranged to connect the piston assembly (94) with the closing spring (56), a hydraulic locking chamber (61) designed to block the closing spring (56), and a solenoid directional control valve (1), in particular a 3 / 2 solenoid directional control valve, wherein a closing damping chamber (58) is formed on one side of the piston assembly (94) facing away from the piston rod (54) between the door closer housing (42) and the piston assembly (94), and wherein the magnetic directional control valve (1) controls at least the pressures in the closing damping chamber (58) and in the blocking chamber (61). [2] Door closer according to claim 1, characterized by a freewheel arrangement which is designed to allow translational movement of the piston assembly (94) decoupled from the closing spring (56) when the closing spring (56) is blocked. [3] Door closer according to any one of the preceding claims, characterized by a fluid-tight partition (53) arranged in the door closer housing (42) between the piston assembly (94) and the closer spring (56), wherein the piston rod (54) passes fluid-tight through the partition (53). [4] Door closer according to any one of the preceding claims, characterized by a closer spring tension piston (55) guided in the door closer housing (42) and bearing against the closer spring (56). [5] Door closer according to claim 4, characterized by , that the locking space (61) is formed between the partition (53) and the closing spring tension piston (55). [6] Door closer according to claim 2, characterized by, that the freewheel arrangement is designed as a sliding coupling which transmits exclusively pressure forces between the closing spring (56) and the piston assembly (94). [7] Door closer according to any one of the preceding claims, characterized by , that the output shaft (48) comprises a cam-shaped rolling contour (49), in particular a cam disk, and the piston assembly (94) comprises at least one cam roller (47, 50) bearing on the rolling contour (49). [8] Door closer according to any one of the preceding claims, characterized by , that a first hydraulic line, in particular a pressure line (P), leads from the blocking space (61) to the solenoid directional control valve (1), a second line, in particular a working line (A), leads from the closing damping space (58) to the solenoid directional control valve (1), and a third line, in particular a tank line (T), leads from the solenoid directional control valve (1) to a tank space (31). [9] Door closer according to claim 3, characterized byan opening damping chamber (60) between the piston assembly (94) and the partition (53) or between the piston assembly (94) and the additional piston (95), and a first throttled connection (78) between the opening damping chamber (60) and the tank chamber (31). [10] Door closer according to claim 9, characterized by a first unthrottled connection (77) between the opening damping chamber (60) and the tank chamber (31), wherein the first throttled connection (78) is always open and the first unthrottled connection (77) is closed or open depending on the position of the piston assembly (94). [11] Door closer according to claim 8, characterized by at least one further throttled connection (75, 76) which is arranged between the closing damping chamber (58) and the tank chamber (31). [12] Door latch according to one of claims 8 to 11, characterized by, that the solenoid directional control valve (1) in a first switching position connects the first line to the third line and blocks the second line, and in a second switching position connects the second line to the third line and blocks the first line. [13] Door closer according to any one of claims 8 to 11, characterized by , that the solenoid directional control valve (1) in a first switching position connects the first line to the second line, and in a second switching position connects the second line to the third line and blocks the first line. [14] Door closer according to any one of the preceding claims, characterized by , that the magnetic directional control valve releases the closing spring (56) when de-energized and allows free movement when energized.

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