WO2009021514A1

WO2009021514A1 - Cap for a valve

Info

Publication number: WO2009021514A1
Application number: PCT/DK2008/000286
Authority: WO
Inventors: Bjarne Frederiksen
Original assignee: Danfoss A/S
Priority date: 2007-08-14
Filing date: 2008-08-13
Publication date: 2009-02-19
Also published as: DE102007038300A1

Abstract

The invention relates to a cap (1) for a valve, comprising a housing (2) in which two actuators (4, 5) are arranged. According to the invention, the cap (1) shall have a low space requirement, wherein the actuators (4, 5) are mechanically arranged in series with one actuator (5) fixed and one actuator (4) mobile in the working direction thereof.

Description

Attachment for a valve

The invention relates to an attachment, in particular a thermostatic attachment, for a valve having a housing in which two actuators are arranged.

From DE 197 54837 A1, a thermostatic attachment for a valve is known which has an actuator designed as a thermostat element and an electric actuator which can be designed as a stepper motor. For setpoint adjustment is located between the thermostatic element and a valve element, an adjustment whose length can be changed by means of the electric actuator. The thermostatic element can be connected via a two-armed lever with the adjuster in connection.

From EP 1 001 327 B1 an attachment for a heating valve is known, wherein an actuator designed as a thermostatic element acts on a valve tappet via a two-armed lever. A likewise attached to the lever spring counteracts the force generated by the thermostatic element. The axis of the valve element, the thermostatic element and the spring extend parallel to each other. An adjustment of the setpoint by means of another actuator is not provided.

Thermostatic attachments for valves are generally used to set or regulate a predetermined setpoint temperature in a room with the aid of a heating element. Thermostatic valve caps have, in most cases, a thermostatic element formed by a bellows-type body filled with a filling whose volume changes with temperature. The thermostatic element acts as a rule via a connecting element on a valve element of the radiator valve. Usually while the radiator valve is throttled the more, the farther the valve element is inserted.

Thermostatic valve heads of this type have long been established and work satisfactorily. In some areas, however, one would like to change the predetermined interaction between the thermostatic element and the valve element, for example in order to lower the predetermined setpoint at a nighttime lowering. The adjustment of the effect context is carried out with the aid of a second actuator, for example, actuates a variable length adjustment between thermostatic element and valve element.

For this procedure, however, a considerable space is required, especially in the axial direction.

The invention is based on the object to provide an essay, which has a low space requirement.

This object is achieved in an essay for a valve of the type mentioned above in that the actuators are mechanically connected in series, with an actuator set and an actuator is movable in its direction of action.

Upon activation of the specified actuator, which leads, for example, to a change in length of the actuator, so the other, movable actuator is moved in its direction of action. Upon activation of the movable actuator, the reaction forces are guided by the specified actuator. An adjusting movement generated by the movable actuator thus adds to an adjustment of the specified actuator. The fixed actuator therefore makes possible a kind of "offset" shift. An additional, variable-length adjustment is not required. Due to the series connection of the actuators, large travel ranges are possible. borrowed, for example, actuators can be used, which move only in their respective longitudinal direction. The contact of the actuators with each other can be done directly or via an intermediate element. Under fixed is to be understood that the actuator has a fixed system, such as an axial stop, a length stop or a rotation stop. It is essential only that the change in length is transmitted from a defined system starting on the movable actuator. Under certain circumstances, it can also be a movement of the specified actuator with respect to the system.

Preferably, the actuators are connected via a two-armed lever with each other. As a result, the two actuators do not have to be arranged behind one another in the effective direction, but can also be placed next to one another, for example. In this case, a translation of the adjustment is possible. For example, the lever arm of the lever is longer, which is assigned to the specified actuator. The fixed actuator then only has to generate a smaller force, but with a larger displacement, to effect a displacement of the movable actuator. If particularly large adjustment movements are desired, however, another embodiment of the lever is also conceivable. The two-armed lever so easy adaptation to different requirements is possible.

In a preferred embodiment, the actuators have mutually parallel effective directions. The actuators can therefore be arranged side by side, with the displacement and power transmission via the two-armed lever. The attachment can thus be designed to be particularly compact, being extended only slightly in the axial direction relative to an attachment without setpoint adjustment in order to accommodate the lever. The entire construction can be made very rigid, so that a precise setting of the desired value can be made. By appropriate choice of the length of the respective lever arm can be easily the desired translation can be set. Here are also large adjustment realized.

Preferably, the movable actuator can be brought into operative connection with a valve element. The movable actuator can either be connected directly to the valve element, or via a connection and / or an actuating element. The adjustment of a desired value is thus effected by a positional shift and optionally by an additional change in length of the movable actuator. An adjustment device between the actuator and the valve element is not required. An adjusting device usually consists of at least two elements that can perform a relative movement to each other. The connection of these two elements is usually game-afflicted. This game affects the setting accuracy. By saving the adjustment can be saved on the one hand costs, on the other hand there is an essay with a smaller space requirement. At the same time a more accurate adjustment of the valve element is possible.

Preferably, the effective direction of at least the movable actuator is parallel to a direction of movement of the valve element. The movable actuator can thus act directly on the valve element, without a transmission or a deflection device is necessary. The force generated by the actuator is thereby transmitted almost lossless to the valve element. At the same time, the space requirement is reduced.

Preferably, the housing has a fastening geometry. This attachment geometry is used for easy attachment of the housing, for example, to a housing of a valve. The attachment geometry can be designed, for example, as a snap spring, which allows a fast and secure connection. Preferably, the lever has a hinge, which is parallel to the direction of movement of the valve element displaceable between a first and a second boundary, wherein the first boundary has a smaller distance from the valve element than the second boundary. The lever defines the axial position of one end of each of the two actuators. By a displacement of the lever due to a displacement of the rotary joint while component tolerances can be compensated or made an adjustment to different actuators.

It is particularly preferred that the rotary joint is pressed by a spring against the first limiting device. This spring now ensures that each lever arm is connected to an actuator. At the same time, the transferable force is limited. If there is too great a force transmission from one actuator to the other, the lever can deflect, it being favorable if the rotary joint can be displaced parallel to the direction of movement of the valve element. Damage to the attachment is thus prevented.

Preferably, one actuator is designed as expansion element and the other actuator as electric drive. An expansion element is a conventional thermostatic element. The attachment can thus work independently of an electrical power supply as a conventional thermostat attachment. The regulation of the temperature, ie the maintenance of the predetermined setpoint temperature, takes place exclusively via the expansion element, wherein no electrical energy is necessary. The electric drive only serves to change the setpoint. Electrical energy is therefore needed only during an adjustment of the setpoint. The energy requirement of the essay is very low.

Preferably, the attachment has at least one battery. A battery is a very low cost component that can power the electric drive. By appropriate selection of the form and Size and the number of batteries, the existing space in the housing can be used as well as possible. An external power supply is then no longer necessary.

Preferably, the electric drive has an electric motor, a spindle and a spindle nut, wherein the spindle nut is guided in a rotationally fixed manner and is engaged with the lever. The electric drive is thus a linear drive whose length changes when actuated. In this case, a translation can take place via the spindle and the spindle nut. It is thereby possible to use a relatively weak motor, which is operated at a high speed. Such a motor can be made relatively small.

It is particularly preferred that the electric motor is designed as a stepper motor5. Stepper motors are on the one hand cost-effective and accurate to control. On the other hand, with knowledge of the steps taken, the position of the engine is always known without the need for additional sensors.

o Preferably, a spring is arranged between the motor and the spindle nut. This spring provides a power relief of the spindle, so that only a smaller force must be generated by the engine. This leads to a lower energy consumption of the engine and thus to an extension of the battery life. 5

The fixed actuator is preferably the electric drive and the movable actuator is the expansion element. The electric drive can thus be fixed in the housing. This makes it particularly easy to provide this with electrical energy. The expansion element requires o no power supply. During the electric drive possibly a

Torque protection needs, this is not for the expansion element necessary. Overall, this results in a particularly simple structure.

In another preferred embodiment, the fixed actuator is the expansion element and the movable actuator of the electric drive. This makes it possible to arrange the expansion element at a greater distance from the valve element. The influence of the temperature of the medium, whose flow is controlled by the valve, on the expansion element is thus reduced. The expansion element can react more sensitively to the ambient temperature.

Preferably, a control device is arranged in the housing. This control device is used to control the electric drive. The power supply of the controller can also be done via a battery. By means of the control device, for example, the influence of the temperature of the medium on the expansion element can be taken into account. The control device can be connected to a control element via which a user can enter setpoint specifications.

Preferably, an electrical current image of the motor can be monitored by the control device. By monitoring the current pattern, a statement can be made as to whether the electric motor was active. In case of failure, a corresponding error message can be issued. The current image can also be used to determine the number of steps that the motor has performed. This can be used to monitor whether the desired setpoint adjustment has been carried out. The controller may also have a zero calibration function. In this case, the electric drive is actuated until the valve is closed. This position is registered. This calibration can be carried out independently at regular intervals, so that a faulty erroneous control is prevented due to a misalignment or adjustment.

Preferably, the control device has a wireless communication device with antenna, wherein the antenna is arranged in the housing. The control can be done by means of a central unit. The entry of a desired value then takes place e.g. no longer directly at the attachment, but at a central, easily accessible location. It is also conceivable that the setpoints of several essays are adjusted simultaneously.

The invention will be described in more detail below with reference to preferred embodiments in conjunction with the drawings. Herein show:

1 shows a schematic cross section through a thermostat attachment of a first embodiment,

2 shows a schematic cross section through a thermostat tower of a second embodiment,

3 shows a schematic cross section through a thermostat attachment of a third embodiment,

4 is a plan view of the thermostat top of FIG. 3 in a schematic representation,

5 shows a schematic cross section through a thermostat attachment of a fourth embodiment,

Fig. 6 is a plan view of the thermostat top of FIG. 5 in a schematic representation and 7 shows a schematic cross section through a thermostat attachment of a further embodiment.

Fig. 1 shows an attachment 1 for a valve which is designed as a thermostatic attachment. The attachment 1 has a housing 2 in which a first actuator 4 and a second actuator 5 formed in this example as expansion element 3 are arranged. The expansion element 3 and the actuator 4 and the actuator 5 are connected to each other via a two-armed lever 6. The second actuator 5 is designed as an electric linear drive. The first actuator 4 is slidably mounted in the direction of its direction of action, the second actuator 5 is fixed with its pointing away from the lever 6 end in the housing 2.

The lever 6 is pivotally mounted with a hinge 7 in the housing 2. The rotary joint 7 is parallel to the effective direction of the expansion element 3 and the actuator 5 between a first boundary 8 and a second boundary 9 in a groove 10 movable. The groove 10 extends parallel to the effective direction of the actuators. With the help of a spring 11, which is arranged between the housing 2 and the lever 6, the

Swivel 7 is pressed in the direction of the first boundary 8. As a result, the system of the lever 6 is secured to both actuators 4, 5.

The expansion element 3 has a bellows 12, in which a plunger 13 is arranged. The expansion element 3 is filled with a material, for example a liquid, which expands when the temperature increases and reduces its volume when the temperature is lowered. Accordingly, with a temperature increase, the bellows 12 is compressed and thus the plunger 13 is displaced outwards. This results in a change in length of the expansion element 3. The expansion element 3 can be brought into operative connection with a valve element 14 of a valve. The direction of movement of the valve element 14 corresponds to the effective direction of the first actuator 4. The groove 10 also extends parallel to the direction of movement of the valve element 14. The valve is, for example, a conventional heating valve, the structure of which is assumed to be known. On the construction of the valve is therefore not discussed. The expansion element 3 is acted upon against its propagation direction on its side facing away from the lever 6 end face by a spring 15. The spring 15 generates a restoring force that is smaller than the forces that can be generated by the actuators 4, 5.

The second actuator 5, the effective direction in this embodiment runs parallel to the effective direction of the expansion element 3 and which is arranged next to the expansion element 3, has an electric motor 16 which drives a spindle 17 to which a spindle nut 18 is rotatably mounted and longitudinally displaceable. The spindle nut 18 is cup-shaped, wherein the lever 6 rests against the closed end of the spindle nut 18. The motor 16 is fixedly mounted in the housing 2 and designed as a stepper motor. It is also conceivable to form the second actuator 5, for example, as a linear stepping motor, in which case u.a. can be dispensed with a spindle.

To power the electric motor 16, a battery 19 is provided, which is shown only schematically. In the housing 2, a control device is arranged, which has not been shown for reasons of clarity. The control device in this case has a wireless communication device with an antenna, via which, for example, setpoint specifications are transmitted to the control device.

If, for example, a general increase in temperature takes place, the electric motor 16 is controlled via the control device in such a way that that the spindle 17 rotates, so that the spindle nut 18 is removed from the motor 16 and thus increases the longitudinal extent of the actuator 5. The number of revolutions of the spindle 17 or the steps of the motor 16 is dependent on the desired temperature change. By the movement of the spindle nut 18, a deflection of the lever 6, which is pivoted about the pivot 7 takes place. The spring 11 is dimensioned such that no noticeable displacement of the rotary joint 7 takes place.

The other side of the lever 6 thereby moves downwards (relative to the orientation of FIG. 1). As a result, the entire expansion element 3 is moved downward and thus causes an adjustment of the valve element 14th

The expansion element 3 then provides for the control of a constant room temperature. For this temperature control so no operation of the electric motor 16 is necessary. The motor 16 thus only requires energy in the short periods in which an adjustment of the desired value takes place.

Fig. 2 shows an essay in a slightly modified form. The expansion element 3 is rotated by 180 °, so that the plunger 13 of the expansion element 3 is in operative connection with the valve element and the lever 6 rests directly on the expansion element 3. As a result, less space must be made available in the region of the valve element 14 for the expansion element 3.

The connection points between lever 6 and expansion element 3 or spindle nut 18 are formed in the form of cam gears. As a result, for example, a non-linear transmission ratio can be achieved. Between motor 16 and spindle nut 18, a spring 20 is arranged, which presses the spindle nut 18 from the motor 16. Thus, the spring 20 counteracts the force exerted by the spring 15 on the expansion element 3 and the lever 6 on the spindle nut 18, for example. In general, the valve element 14 is pressed by means of a valve spring against the expansion element 3. These spring forces, which may for example be in the order of 25 N, are now largely compensated by the spring 20, which should bring a force of about 20 N for it. The engine only needs to apply a large amount of force when large differential pressures and static pressures occur. This leads to a lower energy consumption of the engine, whereby smaller engines can be used. The pressures act on the expansion element 3 via the valve element 14 of the valve.

In this embodiment, the battery 19 is disposed at a different location in the housing 2. The arrangement of the battery 19 is in principle arbitrary. Also, the number of batteries may vary depending on the purpose.

Fig. 3 shows a thermostat attachment 1, wherein the second actuator 5 as

Expansion element 3 is formed and fixed in the housing 2 and the first actuator 4 is movable in the housing and designed as an electric drive. The actuator 4 is thus displaceable in its effective direction. This embodiment has the advantage that the expansion element 3 is not in heat-conducting connection with the valve element 14. The expansion element 3 is thereby influenced substantially only by the ambient temperature. Otherwise, this embodiment corresponds to the embodiment according to FIG. 1.

Fig. 4 shows a plan view of the embodiment of FIG. 3 in a schematic representation. The space inside the housing 2 is good exploited, so that the essay is very compact and requires little space. In case 2 four batteries 19 are housed.

5 shows a further exemplary embodiment of a thermostatic valve attachment. In this case, the lever 6 is formed longer, so that the actuator 5 can be arranged at a greater distance from the actuator 4 and the expansion element 3. In this case, the lever ratio is changed, so that only lower forces must be applied by the actuator 5. Between actuator 5 and expansion element 3 while two batteries 19 are arranged. This is shown in FIG. It can be seen that a sleeker housing can be used with this design. The article according to the invention can thus be adapted to different conditions.

The embodiment shown in Fig. 7 differs from the embodiments already described in that the two actuators 4, 5 have no parallel effective directions. Rather, the second actuator 5 is arranged approximately perpendicular to the first actuator 4, whose effective direction corresponds to the direction of movement of the valve element 14. The connection between the actuators 4, 5 is made via the lever 6, wherein a change in length of the second actuator 5, which is fixed on one side to the housing 2, causes a displacement of the first actuator 4 in its direction of action. The actuators 4, 5 are thus connected to each other and to the valve element 14 mechanically in series.

In this case, the first actuator 4 is designed as expansion element 3 and the second actuator 5 as an electric linear drive. Both actuators 4, 5 thus move only in their respective longitudinal direction.

By using two actuators, it is possible to perform a kind of task distribution between the actuators. The one actuator is used to set a setpoint, the other actuator for control and Monitoring this setpoint is used. This makes it possible to select an optimal actuator for the respective tasks. According to the invention, a force transmission now takes place from one actuator to the other actuator, or through it. Through this series connection of the actuators gearboxes, which usually lead to friction losses and are subject to play, are omitted. This results in a cost savings and a smaller space requirement. At the same time, large adjustment paths can be realized. For example, it can be provided that the actuator designed as an electric linear drive can effect a displacement of 5 mm. This allows setpoint adjustment over a wide range.

Claims

claims

1. attachment, in particular thermostatic attachment, for a valve having a housing in which two actuators are arranged, characterized in that the actuators (4, 5) are mechanically connected in series, wherein an actuator (5) set and a Actuator (4) is movable in its direction of action. 0

2. attachment according to claim 1, characterized in that the actuators (4, 5) via a two-armed lever with each other.

3. Attachment according to claim 1 or 2, characterized in that die5 actuators (4, 5) have mutually parallel directions of action.

4. Attachment according to one of claims 1 to 3, characterized in that the movable actuator (4) with a valve element (14) can be brought into operative connection. 0

5. Attachment according to one of claims 1 to 4, characterized in that the effective direction of at least the movable actuator (4) is parallel to a direction of movement of the valve element (14). 5

6. Attachment according to one of claims 1 to 5, characterized in that the housing (2) has a fastening geometry.

7. Attachment according to one of claims 1 to 6, characterized in that the lever (6) has a pivot joint (7) which is parallel to the direction o movement of the valve element (14) between a first

Limit (8) and a second boundary (9) is displaceable, wherein the first boundary (8) has a smaller distance from the valve element (14) than the second boundary (9).

8. attachment according to claim 7, characterized in that the 5 rotary joint (7) by a spring (11) against the first limiting device (8) is pressed.

9. Attachment according to one of claims 1 to 8, characterized in that the one actuator as expansion element (3) and the other l o actuator is designed as an electric drive.

10. Attachment according to one of claims 1 to 9, characterized in that it comprises at least one battery (19).

15. Attachment according to one of claims 1 to 10, characterized in that the electric drive has an electric motor (16), a spindle (17) and a spindle nut (18), wherein the spindle nut (18) is rotatably guided and with the lever (6) is engaged.

20

12. attachment according to claim 1 1, characterized in that the electric motor (16) is designed as a stepping motor.

13. Attachment according to claim 11 or 12, characterized in that 25 between the motor (16) and the spindle nut (18) has a spring (20) is arranged.

14. Attachment according to one of claims 9 to 13, characterized in that the fixed actuator (5) of the electric drive and the

3 o movable actuator (4) is the expansion element (3).

15. Attachment according to one of claims 9 to 13, characterized in that the fixed actuator (5), the expansion element (3) and the movable actuator (4) is the electric drive.

16. Attachment according to one of claims 1 to 15, characterized in that a control device is arranged in the housing.

17. Attachment according to claim 16, characterized in that an electrical current pattern of the motor (16) can be monitored by the control device.

18. Attachment according to one of claims 16 or 17, characterized in that the control device comprises a wireless communication device with antenna, wherein the antenna in the housing (2) is arranged.