Gas pressure spring with expansion material, actuation system for a flap with the gas pressure spring, method for producing the gas pressure spring

Abstract

The invention relates to a gas pressure spring (100), comprising a working chamber (120) filled with a working gas, a working piston (130) movably arranged in the working chamber along a stroke axis (H), a piston rod (131) fastened to the working piston (130) and guided out of the working chamber (120) along the stroke axis (H), a supporting piston (140) which is movable along a supporting axis (S) and delimits the working chamber (120) on one side, an expansion material chamber (150) which is filled with an expansion material which expands during heating, and a plunger (151) which is arranged at least partly in the expansion material chamber (150) and can be driven out of the expansion material chamber (150) by expansion of the expansion material. The plunger (151) is mechanically connected to the supporting piston (140) in such a way that, when the expansion material is heated above a switching temperature, expansion of the expansion material moves the supporting piston (140) in a direction reducing the size of the working chamber (120).

Description

GAS SPRING WITH EXPANSION MATERIAL, ACTUATION SYSTEM FOR A FLAP WITH THE GAS SPRING, MANUFACTURING PROCESS OF THE GAS SPRING

[0001] The invention relates to a gas pressure spring comprising a working chamber filled with a working gas, a working piston arranged displaceably in the working chamber along a stroke axis, a piston rod fastened to the working piston and guided out of the working chamber along the stroke axis, a support piston displaceable along a support axis which delimits the working chamber on one side, an expansion chamber filled with an expansion material which expands when heated and a plunger arranged at least in sections in the expansion chamber and which can be expelled from the expansion chamber by an expansion of the expansion material.

[0002] The invention further relates to an actuating system for a flap comprising a gas pressure spring according to the invention and a method for producing the gas pressure spring.

[0003] Temperature-driven actuators are known from the prior art, for example, for the temperature-dependent operation of greenhouse windows without an external power supply. Such actuators typically comprise an expansion material enclosed in a cartridge, which, when heated above a predetermined switching temperature, expands significantly due to a phase transition, thereby expelling a plunger from the cartridge. The movement of the plunger can be transmitted to a window, for example, via a lever system, to automatically open the window when the switching temperature is exceeded. If the temperature drops below the switching temperature, the expansion material contracts and the plunger is pushed back into the cartridge, for example by a spring or by the weight of the window, so that the window closes again.

[0004] A disadvantage of the actuators described above is that the plunger only travels a short distance during a switching operation and provides only a small extension force. Therefore, operating a window usually requires a complex lever system to convert the stroke into an amplitude sufficient to open the window, as well as additional springs to amplify the extension force to a force sufficient to open the window.

[0005] The object of the invention is to provide a compact, simply constructed and cost-effective temperature-driven actuator, in particular for operating a window, with a large stroke and high extension force.

[0006] The present invention provides a gas spring according to claim 1, which solves the technical problem. The problem is also solved by an actuating system for a flap according to claim 11 and by a manufacturing method for the gas spring according to claim 14. Advantageous embodiments are the subject of the dependent claims.

[0007] A gas spring according to the invention comprises a working chamber filled with a working gas. The working chamber is, for example, hollow-cylindrical in shape. The working gas is, for example, an inert gas, in particular nitrogen.

[0008] The gas spring comprises a working piston that is arranged in the working chamber so that it can move along a stroke axis. The working piston divides the working chamber, for example, into a first sub-chamber along the stroke axis in front of the working piston and a second sub-chamber along the The stroke axis is located behind the working piston. The working piston can comprise at least one overflow channel that connects the first subchamber to the second subchamber in a gas-conducting manner. The working chamber is, for example, rotationally symmetrical to the stroke axis.

[0009] The gas spring comprises a piston rod attached to the working piston and extending out of the working chamber along the stroke axis. The gas spring includes, for example, a guide-seal assembly through which the piston rod is guided out of the working chamber. The guide-seal assembly guides the piston rod along the stroke axis and / or seals the working chamber gas-tight.

[0010] The gas spring comprises a support piston that can be moved along a support axis and defines the working chamber on one side. By moving the support piston, the volume of the working chamber and the working gas pressure can be adjusted.

[0011] The gas spring comprises an expansion chamber filled with an expansion material that expands when heated. The expansion chamber is, for example, hollow-cylindrical and / or rotationally symmetrical to the support axis. The expansion material may contain, for example, an oil, a wax, and / or a hard paraffin. When heated above a switching temperature, the expansion material undergoes a phase transition and expands significantly.

[0012] The gas pressure spring comprises a plunger which is arranged at least partially in the expansion chamber and which can be expelled from the expansion chamber by an expansion of the expansion material.

[0013] The plunger is mechanically connected to the support piston in such a way that when the expansion material is heated above a switching temperature, an expansion of the expansion material displaces the support piston in a direction that reduces the working chamber.

[0014] When the expansion material is heated above the switching temperature, the plunger moves the support piston so that the working chamber is reduced. This increases the working gas pressure in the working chamber, so that the The piston rod is expelled from the working chamber. The displacement of the plunger against the working gas pressure can be supported, for example, by a spring element integrated into the gas spring. By appropriately dimensioning the gas spring and selecting the appropriate working gas pressure, the piston rod can provide a greater stroke and a higher extension force than the plunger. By integrating the expansion chamber into the gas spring, a compact, cost-effective, and simply constructed temperature-driven actuator is achieved.

[0015] The gas spring preferably comprises a support chamber filled with a support gas, wherein the support piston separates the support chamber from the working chamber in a gas-tight manner. The support gas is, for example, an inert gas, in particular nitrogen. The support chamber is, for example, hollow-cylindrical and / or rotationally symmetrical to the support axis. The pressure of the support gas assists the displacement of the support piston against the working gas pressure of the working gas, so that the piston rod, which is pushed out of the working chamber when the expansion material expands, can exert a greater extension force than the plunger pushed out of the expansion material chamber.

[0016] The expansion chamber is preferably located within the support chamber. This results in a particularly compact and simple design of the gas spring. If the expansion chamber were located outside the support chamber, a transition area between the expansion chamber and the support chamber would have to be sealed gas-tight from the surroundings of the gas spring to prevent the support gas from escaping from the support chamber. This requirement is advantageously eliminated if the expansion chamber is located within the support chamber.

[0017] The working piston and / or the piston rod is preferably in a maximum compressed state of the gas spring, in which the When the piston rod is fully inserted into the working chamber, it is in mechanical contact with the support piston. As a result, the piston rod is immediately pushed out of its fully inserted position into the working chamber with great force as soon as the support piston is displaced toward the piston rod by the expansion of the expansion material. The immediately available force can be used, for example, to move a flap actuated by the gas spring from a dead center position, allowing the gas spring to open or close the flap without additional support, for example, from mechanical springs.

[0018] The expansion chamber is preferably tightly enclosed by an expansion cartridge for the expansion material. The expansion cartridge is, for example, hollow-cylindrical and / or rotationally symmetrical to the support axis. The expansion cartridge is made of a metal, in particular steel, for example. The expansion cartridge can be pre-assembled with the plunger and the support piston. Except for the pre-assembled expansion cartridge, the gas spring can be designed like a conventional gas spring, so that a conventional gas spring with the pre-assembled expansion cartridge can be particularly easily converted into a gas spring according to the invention.

[0019] A working gas pressure of the working gas preferably corresponds to a support gas pressure of the support gas in a maximum compressed state of the gas spring, in which the piston rod is pushed maximally into the working chamber. Because the maximum working gas pressure in the maximum compressed state of the gas spring is not greater than the support gas pressure, the expansion material only needs to exert a small force to displace the support piston against the working gas pressure. Thus, an expansion material cartridge enclosing the expansion chamber only needs to have low mechanical stability and can therefore be designed to be lightweight and cost-effective. A particularly lightweight and cost-effective expansion material cartridge can be used if the expansion material cartridge is arranged in the gas spring in such a way that the Expansion cartridge can be supported on the inside of a pressure tube of the gas spring.

[0020] Because the support gas pressure acts on a smaller area than the working gas pressure due to the piston, a resulting force acts on the support piston at the same working gas pressure and support gas pressure, driving the piston into the expansion chamber. This ensures that the piston is pushed back into the expansion chamber as soon as the expansion material contracts due to cooling. Consequently, the piston rod moves reversibly out of the working chamber when heated and into the working chamber when cooled.

[0021] The expansion material preferably comprises an expansion wax, for example, an expansion wax described in patent application DE 10 2020 113 749 A1. The expansion wax preferably comprises an alkane, a primary alcohol, and / or a thermally conductive additive, preferably graphite. A thermally conductive additive advantageously shortens the reaction time of the expansion material to a temperature change.

[0022] The gas spring preferably comprises a temperature control element for controlling the temperature of the wax, wherein the temperature control element preferably comprises a heating resistor and / or a Peltier element. The temperature control element also allows temperature-independent movement of the piston rod, for example, to actuate a flap, thus allowing for more versatile use of the gas spring.

[0023] The gas spring preferably comprises a pressure tube, with the working chamber, the expansion chamber, and preferably the expansion cartridge and / or the support chamber being arranged in the pressure tube. The pressure tube is, for example, hollow-cylindrical, rotationally symmetrical to the stroke axis, and / or designed like a pressure tube of a conventional gas spring. The arrangement of the chambers in the common pressure tube results in a particularly simple design of the gas spring.

[0024] The stroke axis and the support axis are preferably identical. Thus, the movements of the working piston, the piston rod, the support piston and the plunger along a common axis, which results in particularly efficient power transmission and a particularly simple design of the gas spring.

[0025] An actuating system for a flap according to the invention comprises a gas pressure spring according to the invention, wherein the gas pressure spring is mechanically connected to the flap such that extension of the piston rod from the working chamber causes the flap to be actuated. The flap can be, for example, a ventilation flap, a fire protection flap, or a window, in particular a greenhouse window.

[0026] Depending on the application, the actuation can be an opening or closing of the damper. With a fire damper, the gas spring is preferably connected in such a way that extending the piston rod causes the fire damper to close when the switching temperature of the wax is exceeded. With a ventilation damper or a window, the gas spring is preferably connected in such a way that extending the piston rod causes the ventilation damper or window to open when the switching temperature of the wax is exceeded.

[0027] The working gas pressure of the gas spring is preferably selected such that the extension force of the gas spring is sufficient to actuate the flap in a high-temperature state of the gas spring, in which the plunger is maximally extended from the expansion chamber. This ensures reliable flap actuation.

[0028] The working gas pressure of the gas spring is preferably selected such that the extension force of the gas spring in a low-temperature state of the gas spring, in which the plunger is pushed into the expansion chamber to its maximum extent, is insufficient to actuate the flap. This ensures that the gas spring does not inadvertently actuate the flap in the low-temperature state. Particularly preferably, the working gas pressure is selected to be only slightly lower than the pressure required to actuate the flap in the low-temperature state. would be necessary, so that the expansion material only needs to apply a small force in the high-temperature state to operate the flap.

[0029] A method according to the invention for producing a gas spring according to the invention comprises providing an expansion material cartridge, wherein the expansion material cartridge encloses an expansion chamber filled with an expansion material that expands upon heating, and comprises a plunger arranged at least partially in the expansion chamber and expellable from the expansion chamber by an expansion of the expansion material. The plunger is mechanically connected to a support piston. The expansion material cartridge can thus be filled with the expansion material and pre-assembled with the plunger and the support piston independently of the other manufacturing steps of the gas spring.

[0030] The method comprises arranging the expansion material cartridge in a pressure tube of the gas spring such that the support piston is displaceable along a support axis and delimits the working chamber of the gas spring on one side. When the expansion material is heated above a switching temperature, expansion of the expansion material displaces the support piston in a direction that reduces the working chamber. Except for the expansion material cartridge, the gas spring can be configured like a previously known gas spring. Thus, a manufacturing method for a previously known gas spring with the aforementioned steps of the method according to the invention can be easily modified to produce a method according to the invention for manufacturing a gas spring according to the invention.

[0031] Further advantages, objects and features of the invention will be explained with reference to the following description and the accompanying drawings, in which exemplary objects according to the invention are shown.

[0032] Figure 1 shows a gas spring according to the invention at low temperature and with the piston rod retracted.

[0033] Figure 2 shows a gas spring according to the invention at high temperature and with the piston rod extended.

[0034] Figure 1 shows a gas pressure spring 100 according to the invention at low temperature and with the piston rod 131 retracted.

[0035] The gas pressure spring 100 shown comprises a working chamber 120 filled with a working gas, for example nitrogen, a working piston 130 arranged displaceably in the working chamber 120 along a stroke axis H, and a piston rod 131 fastened to the working piston 130 and led out of the working chamber 120 along the stroke axis H. The working piston 130 can have a channel 133 through which the working gas can flow through the working piston 130 along the stroke axis H.

[0036] The gas spring 100 comprises a support piston 140 that is movable along a support axis S, which, for example, coincides with the stroke axis H, and which delimits the working chamber 120 on one side. The support piston 140 delimits the working chamber 120, for example, on the side opposite the piston rod 131.

[0037] The gas pressure spring 100 comprises an expansion chamber 150 filled with an expansion material that expands when heated, and a plunger 151 arranged at least in sections in the expansion chamber 150 and expellable from the expansion chamber 150 by an expansion of the expansion material, in particular through an outlet opening 152, wherein the plunger 151 is mechanically connected to the support piston 140 such that when the expansion material is heated above a switching temperature, an expansion of the expansion material displaces the support piston 140 in a direction that reduces the size of the working chamber 120 along the support axis S.

[0038] The gas pressure spring 100 comprises a support chamber 160 filled with a support gas, wherein the support piston 140 separates the support chamber 160 from the working chamber 120 in a gas-tight manner, and wherein the expansion chamber 150 is arranged within the support chamber 160.

[0039] The support piston 140 may have a seal 141 to separate the support chamber 160 from the working chamber 120 in a gas-tight manner.

[0040] The gas spring 100 comprises, for example, a pressure tube 110, wherein the working chamber 120, the expansion chamber 150 and the support chamber 160 are arranged in the pressure tube 110.

[0041] The expansion chamber 150 is, for example, tightly enclosed by an expansion cartridge 153 for the expansion material, wherein the expansion cartridge 153 is preferably arranged in the pressure pipe 110, in particular is fastened to the pressure pipe 110.

[0042] Figure 1 shows the gas spring 100 at a low temperature. Therefore, the expansion material in the expansion chamber 150 has a small volume, and the plunger 151 is pushed into the expansion chamber 150 to its maximum extent by the support gas in the support chamber 160. As a result, the support piston 140 connected to the plunger 151 is in a position where the volume of the working chamber 120 is at its maximum. The pressure of the working gas in the working chamber 120 and the resulting spring force of the gas spring 100 are therefore low.

[0043] Figure 2 shows a gas pressure spring 100 according to the invention at a high temperature above a switching temperature and with the piston rod 131 extended.

[0044] Due to the high temperature, the expansion material in the expansion chamber 150 has expanded and expelled the plunger 151 to its maximum extent from the expansion chamber 150. As a result, the support piston 140 connected to the plunger 151 is in a position in which the volume of the working chamber 120 is minimal. The pressure of the working gas in the working chamber 120 and the resulting spring force of the gas spring 100 are consequently higher than in the state shown in Figure 1 due to both the higher temperature and the smaller volume of the working chamber 120. The spring force of the gas spring 100 according to the invention thus increases more sharply with increasing temperature than the spring force of a gas spring known from the prior art. As a result, the gas spring 100 according to the invention can be used, for example, for automatic and temperature-dependent opening or closing of a flap.

[0045] The gas spring 100 can, for example, be designed such that the support piston 140 comes into mechanical contact with the working piston 130 or the piston rod 131 at a high temperature when the piston rod 131 is pushed into the gas spring 100 to its maximum extent. Due to the mechanical contact, the expansion material can exert an additional extension force on the piston rod 131 via the plunger 151 and the support piston 140 when the expansion material expands, so that, for example, a particularly large force is available for actuating a flap actuated by the gas spring 100.

Claims

Claims 1. Gas pressure spring (100) comprising a. a working chamber (120) filled with a working gas, b. a working piston (130) arranged so as to be displaceable in the working chamber (120) along a stroke axis (H), c. a piston rod (131) fastened to the working piston (130) and guided out of the working chamber (120) along the stroke axis (H), d. a support piston (140) displaceable along a support axis (S) and delimiting the working chamber (120) on one side, e. an expansion chamber (150) filled with an expansion material which expands when heated, and f. a plunger (151) arranged at least in sections in the expansion chamber (150) and which can be expelled from the expansion chamber (150) by an expansion of the expansion material, characterized in that g.the plunger (151) is mechanically connected to the support piston (140) in such a way that when the expansion material is heated above a switching temperature, an expansion of the expansion material displaces the support piston (140) in a direction which reduces the size of the working chamber (120).

2. Gas pressure spring (100) according to claim 1, wherein the gas pressure spring (100) comprises a support chamber (160) filled with a support gas, wherein the support piston (140) separates the support chamber (160) from the working chamber (120) in a gas-tight manner.

3. Gas spring (100) according to claim 2, wherein the expansion chamber (150) is arranged within the support chamber (160).

4. Gas pressure spring (100) according to one of claims 1 to 3, wherein the working piston (130) and / or the piston rod (131) is in mechanical contact with the support piston (140) in a maximum compressed state of the gas pressure spring (100), in which the piston rod (131) is maximally inserted into the working chamber (120).

5. Gas pressure spring (100) according to one of claims 1 to 4, wherein the expansion chamber (150) is tightly enclosed by an expansion cartridge (153) for the expansion material.

6. Gas pressure spring (100) according to one of claims 1 to 5, wherein a working gas pressure of the working gas in a maximum compressed state of the gas pressure spring (100), in which the piston rod (131) is maximally inserted into the working chamber (120), corresponds to a support gas pressure of the support gas.

7. Gas spring (100) according to one of claims 1 to 6, wherein the expansion material comprises an expansion wax, preferably with an alkane and / or a primary alcohol.

8. Gas spring (100) according to claim 7, wherein the expansion wax comprises a heat-conducting additive, preferably graphite.

9. Gas pressure spring (100) according to one of claims 1 to 8, wherein the gas pressure spring (100) comprises a tempering element for tempering the expansion wax, wherein the tempering element preferably comprises a heating resistor and / or a Peltier element.

10. Gas pressure spring (100) according to one of claims 1 to 9, wherein the gas pressure spring (100) comprises a pressure tube (110), wherein the working chamber (120), the expansion chamber (150) and preferably the expansion cartridge (153) and / or the support chamber (160) are arranged in the pressure tube (110).

11. Gas spring (100) according to one of claims 1 to 10, wherein the stroke axis (H) and the support axis (S) are identical.

12. Actuating system for a flap comprising a gas pressure spring (100) according to one of the preceding claims, wherein the gas pressure spring (100) is mechanically connected to the flap such that an extension of the piston rod (131) from the working chamber (120) causes an actuation of the flap.

13. Actuating system according to claim 12, wherein a working gas pressure of the working gas of the gas pressure spring (100) is selected such that an extension force of the gas pressure spring (100) in a high-temperature state of the gas pressure spring (100), in which the plunger (151) is maximally extended from the expansion chamber (150), is sufficient to actuate the flap.

14. Actuating system according to claim 12 or 13, wherein a working gas pressure of the working gas of the gas pressure spring (100) is selected such that an extension force of the gas pressure spring (100) in a low-temperature state of the gas pressure spring (100), in which the plunger (151) is maximally inserted into the expansion chamber (150), is insufficient to actuate the flap.

15. A method for producing a gas pressure spring (100) according to one of claims 1 to 11, comprising the following steps: a. providing an expansion material cartridge (153), i. the expansion material cartridge (153) enclosing an expansion chamber (150) filled with an expansion material that expands when heated, and ii. comprising a plunger (151) arranged at least partially in the expansion chamber (150) and expellable from the expansion chamber (150) by an expansion of the expansion material, iii. a support piston (140) being mechanically connected to the plunger (151), b. arranging the expansion material cartridge (153) in a pressure tube (110) of the gas pressure spring (100), i. so that the support piston (140) is displaceable along a support axis (S) and delimits the working chamber (120) of the gas pressure spring (100) on one side, and ii.such that when the expansion material is heated above a switching temperature, an expansion of the expansion material displaces the support piston (140) in a direction that reduces the working chamber (120).

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