Pressure Regulator

Abstract

A pressure regulator (10) is proposed for setting the pressure in a container (14) connected downstream of the pressure regulator and connected to the fluid therewith, wherein the pressure regulator (10) comprises: a main fluid channel (18) having a fluid input end (20) and a fluid output end (22) leading to the container (14); and a regulating valve (24) for setting the fluid pressure at the fluid output end (22), wherein a bypass channel (30) is branched off from the main fluid channel (18) downstream of the regulating valve (24), the main fluid channel (18) can be vented via the bypass channel, and wherein the flow cross section of the bypass channel (30) is smaller than the maximum flow cross section of the main fluid channel (18).

Description

Technical Field

[0001] The invention relates to a pressure regulator for setting the pressure in a container which is connected downstream of the pressure regulator and is fluidically connected thereto. Background Art

[0002] The regulation of the pressure in the container is useful, for example, in pressure-time controlled dosing processes.

[0003] In the process of pressure-time controlled quantitative dispensing, a container containing the liquid to be quantitatively dispensed is loaded with a defined pressure. The amount of liquid is quantitatively dispensed in a time-dependent manner via the opening duration of the quantitative dispensing valve. This quantitative dispensing is used, for example, in in vitro diagnostics or in liquid transfer robots. Liquids are primarily quantitatively dispensed here, but it is also possible to consider the quantitative dispensing of gases.

[0004] The accuracy of the quantity metered from a pressurized container is dependent on the pressure prevailing in the container, the temperature or the temperature-dependent viscosity of the liquid and the opening time of the metering valve.

[0005] In order to ensure precise pressure regulation in small containers, it is necessary to ensure that the change of the variable outflow from the liquid-filled container is ensured as quickly as possible. Usually, in vitro diagnostic reagents are stored in containers made of glass or plastic with a container volume of 1.5 ml to 2 ml. In this case, the container is usually filled only to such an extent that there is still an air cushion of at least 0.5 ml in the container.

[0006] The challenge is to keep the pressure in the container constant, for example at 35 mbar. As soon as the metering valve is open and liquid flows out of the container, the pressure must be readjusted. In small volumes, readjustment quickly leads to overshoot or undershoot, that is to say pressure fluctuations, in particular pressure fluctuations in the range of + / -4 mbar. Summary of the invention

[0007] It is therefore an object of the present invention to provide a pressure regulator by means of which the pressure in a container can be regulated particularly accurately.

[0008] The objective is achieved according to the present invention by a pressure regulator, which is used to set the pressure in a container connected downstream of the pressure regulator and connected to the fluid therewith, wherein the pressure regulator comprises: a main fluid channel, the main fluid channel having a fluid input end and a fluid output end leading to the container; and a regulating valve for setting the fluid pressure at the fluid output end, wherein a bypass channel is separated from the main fluid channel downstream of the regulating valve, the main fluid channel can be exhausted via the bypass channel, and wherein the flow cross section of the bypass channel is smaller than the maximum flow cross section of the main fluid channel.

[0009] The maximum flow cross section of the main fluid channel is the flow cross section when the regulating valve is maximally opened.

[0010] By providing a bypass channel, a continuous outflow of compressed air from the main fluid channel is possible. As a result, tolerances and pressure fluctuations when regulating the pressure in the container connected downstream of the pressure regulator are reduced. In this way, a pressure-time controlled dosing process can be particularly precise.

[0011] By making the flow cross section of the bypass channel smaller than the maximum flow cross section of the main fluid channel, it is ensured that sufficient fluid pressure can be generated at the fluid outlet, so that a larger amount of fluid can be conveyed to the main fluid channel than can flow out through the bypass channel.

[0012] The fluid is, for example, air or other gases.

[0013] The venting is achieved in particular in that the bypass channel opens into an outer wall of the pressure regulator and into the surroundings of the pressure regulator.

[0014] In the simplest case, the bypass channel is realized in particular by a bypass bore.

[0015] The maximum flow cross section of the bypass channel is, for example, between 0.1% and 10% of the maximum flow cross section of the main fluid channel. This allows sufficiently fast pressure build-up. With a bypass channel having such a flow cross section, pressure fluctuations of less than 0.5 bar can be achieved in a container connected downstream of the pressure regulator.

[0016] According to one embodiment, the pressure regulator has an electromagnetically operable exhaust valve, wherein the flow cross section of the bypass channel can be set by means of the exhaust valve. Thus, the flow cross section of the bypass channel can be set in relation to the opening state of the regulating valve and / or the position of the dosing valve, by means of which the fluid outflow from the pressure-loaded container can be regulated. In particular, the loss of fluid flowing through the main fluid channel can be minimized, for example, in that the bypass channel can be closed by the exhaust valve when no pressure regulation is being carried out. In other words, the bypass channel can be opened by means of the exhaust valve only when pressure regulation or dosing is being carried out.

[0017] The exhaust valve is in particular a further regulating valve.

[0018] If the regulating valve is in the open state and the exhaust valve is in a slightly open state, a particularly fast reaction to pressure fluctuations in the container can be achieved. If the exhaust valve is thus already in a slightly open state, the transition to a less or more open state takes place in only a few microseconds, in particular in less than 5 microseconds. In contrast, the exhaust valve requires at least 20 microseconds to transition from the closed position to the open position.

[0019] The pressure regulator comprises, for example, a microcontroller, by means of which the exhaust valve can be controlled. Alternatively, the exhaust valve can be controlled via a superordinate system.

[0020] According to one embodiment, the pressure regulator has a control unit for controlling the regulating valve, which is designed to set the output pressure at the fluid output to a desired value by correspondingly controlling the regulating valve. As a result, the output pressure can be regulated particularly accurately.

[0021] The pressure regulator preferably comprises a pressure sensor, which is arranged downstream of the regulating valve and is fluidically connected to the main fluid channel so as to measure the actual pressure in the main fluid channel downstream of the regulating valve. Therefore, the actual pressure in the main fluid channel can be monitored via the pressure sensor.

[0022] Preferably, the control unit is designed to send the actual pressure measured by the pressure sensor as an input signal to the regulating valve. The pressure regulator can thereby regulate the pressure in the main fluid channel or at the fluid output particularly accurately. In this way, the accuracy of the pressure-time controlled metered dispensing performed from the downstream connected container is particularly good.

[0023] The pressure regulator can have a carrier plate and a housing cover attached to the carrier plate, in which the main fluid channel extends, wherein the housing cover and the carrier plate spatially delimit the electronics of the pressure regulator. The pressure regulator can thus form a closed unit, in particular a "plug and play" device.

[0024] For example, electrical connections of the pressure regulator, in particular bus terminals and analog inputs, are arranged on the housing cover.

[0025] The regulating valve, the exhaust valve, the pressure sensor and / or the electronic module can be arranged on the carrier plate. The pressure regulator can thus be designed to be particularly compact.

[0026] According to one embodiment, the pressure regulator is designed as a pipeline-free system. As a result, the pressure regulator is particularly stable. This means that the main fluid channel in the pressure regulator does not have a pipeline, but a channel in the component, in particular in the block. Likewise, there is no pipeline to the bypass channel or the regulating valve. The bypass channel itself is also not a pipeline. All channels are preferably designed in a one-piece component, for example in a plate or generally in a block.

[0027] The exhaust valve can be designed as a regulating valve, ie a special design of a continuous valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other advantages and features of the present invention are apparent from the following description and the following drawings, to which reference is made. In the drawings:

[0029] Figure 1 A pressure regulator according to the invention is schematically shown, to which a container is connected,

[0030] Figure 2 An exploded view of a pressure regulator according to the present invention is shown,

[0031] Figure 3 Show Figure 2 Another exploded view of the pressure regulator in

[0032] Figure 4 The carrier plate of the pressure regulator is shown.

[0033] Figure 5 Show Figure 4 A cross-sectional view of the carrier plate in FIG.

[0034] Figure 6 Show Figure 2 Side view of the pressure regulator in

[0035] Figure 7 Shown along Figure 6 The line AA in FIG. 1 passes through a portion of the cross section of the pressure regulator, and

[0036] Figure 8 A diagram is shown for illustrating the pressure fluctuations when using a pressure regulator with and without a bypass channel. DETAILED DESCRIPTION

[0037] Figure 1 The schematic diagram illustrates a pressure regulator 10 according to the invention, which is connected to a container 14 containing a liquid 12. The holding volume of the container 14 lies, for example, between 0.1 ml and 5 ml. Instead of a liquid 12, the container 14 can also contain a gas to be dosed.

[0038] The pressure regulator 10 is particularly suitable for regulating the pressure in the container 14 so that a defined pressure is present in the container 14 at any time. In this way, the liquid 12 can be metered out of the container 14 in a pressure-time controlled manner. Here, the valve 16 connected downstream of the container 14, in particular the metering valve, is opened in a defined time period. If the pressure in the container 14 is always constant, then when the valve 16 is open, the same amount of liquid always flows out of the container 14 in a defined time period.

[0039] The pressure regulator 10 comprises a main fluid channel 18 having a fluid input 20 and a fluid output 22 leading to a connected container 14 .

[0040] An unregulated preliminary pressure is present at the fluid inlet 20 . In order to set a defined pressure at the fluid outlet 22 and thus in the container 14 , the pressure regulator 10 comprises a regulating valve 24 .

[0041] The compressed air present at the fluid outlet 22 acts, for example, as a pressure pad, on the container 14 , from which very precise small quantities of liquid can be metered in a time-controlled manner via the valve 16 .

[0042] Furthermore, a pressure sensor 26 is provided, which is arranged downstream of the control valve 24 .

[0043] The pressure sensor 26 is fluidly connected to the main fluid passage 18 in order to measure the actual pressure in the main fluid passage 18 downstream of the regulating valve 24 .

[0044] Downstream of the regulating valve 24, in particular downstream of the pressure sensor 26, a bypass channel 30 branches off from the main fluid channel 18. Venting of the main fluid channel 18 can be achieved via the bypass channel 30, that is, a portion of the fluid flowing through the main fluid channel 18 can flow out of the pressure regulator 10 via the bypass channel 30.

[0045] The flow cross section of the bypass channel 30 is smaller than the maximum flow cross section of the main fluid channel 18. As a result, a reliable pressure buildup in the main fluid channel 18 is possible.

[0046] The maximum flow cross section of the bypass channel 30 is, for example, between 0.1% and 10% of the maximum flow cross section of the main fluid channel 18 .

[0047] In one embodiment, the bypass passage 30 may be continuously open so that fluid may continuously flow out of the main fluid passage 18 .

[0048] In another embodiment illustrated in the figure, an electromagnetically operable exhaust valve 32 configured as a regulating valve is provided, wherein the flow cross section of the bypass channel 30 can be set by means of the exhaust valve 32. In particular, the flow cross section of the bypass channel 30 can be set by means of the exhaust valve 32 to a value of up to 10% of the maximum flow cross section of the main fluid channel 18.

[0049] When no pressure regulation is taking place, the bypass channel 30 can be closed by means of the vent valve 32. As a result, pressure losses can be minimized. During pressure regulation, however, the bypass channel 30 is continuously open.

[0050] Figure 2 An exploded view of the pressure regulator 10 is shown.

[0051] exist Figure 2 As can be seen in FIG. 1 , the pressure regulator 10 has a carrier plate 34 and a housing cover 36 attached to the carrier plate 34 . The housing cover 36 can be clipped onto the carrier plate 34 .

[0052] The main fluid channel 18 extends in the carrier plate 34, wherein Figure 2 Only the fluid outlet end 22 of the main fluid channel 18 can be seen.

[0053] In addition, Figure 2 3 , an exhaust opening 37 is shown, which is arranged in particular on the outer wall of the carrier plate 34 . Via the exhaust opening 37 , the bypass channel 30 opens into the surroundings of the pressure regulator 10 .

[0054] The housing cover 36 and the carrier plate 34 delimit an electronics space 38 of the pressure regulator 10 .

[0055] The regulating valve 24, the exhaust valve 32 and the pressure sensor 26 are arranged on the carrier plate 34. For example, the regulating valve, the exhaust valve and the pressure sensor are screwed on the carrier plate 34. The pressure sensor 26 is arranged on a printed circuit board.

[0056] The pressure regulator 10 further comprises an electronics module 40, which is likewise arranged on the carrier plate 34. The electronics module 40 is, for example, a printed circuit board.

[0057] The regulating valve 24 , the exhaust valve 32 and the pressure sensor 26 are connected to the electronic module 40 via electrical lines 50 .

[0058] In order to hold the electronic module 40, guides 42 are provided in the carrier plate 34, into which the electronic module 40 is pushed. The electronic module 40 can thus be mounted particularly easily. When the housing cover 36 is placed on the carrier plate 34, the electronic module 40 can no longer be detached from the guides 42. However, it is also possible to fix the electronic module 40 in another way, in particular to screw it.

[0059] Electrical interfaces 44, 46 of the pressure regulator 10 are provided on the housing cover 36. The interface 44 provides, for example, a bus terminal for communication, such as a CanOpen interface and a 24V power supply. The interface 46 provides, for example, an analog input for an external sensor and a 12V voltage supply for optionally connecting other devices, as well as a digital output.

[0060] To regulate the pressure in the container 14, the pressure regulator 10 comprises a control unit (not shown for simplicity) for controlling the regulating valve 24. The control unit is designed to set the output pressure at the fluid output 22 to a desired value by correspondingly controlling the regulating valve 24.

[0061] The control unit can be arranged outside the electronics space 38 and connected to the pressure regulator 10 via an interface 46 , in particular via a bus terminal. Alternatively, the control unit can also be integrated in the electronics module 40 .

[0062] Furthermore, the control unit is designed to transmit the actual pressure measured by the pressure sensor 26 as an input signal to the regulating valve 24. If the actual pressure deviates from the desired pressure, a corresponding readjustment can be performed.

[0063] The pressure regulator 10 is designed as a pipeline-free system. This means that all fluid-conducting parts of the pressure regulator 10, namely the main fluid channel 18 and the bypass channel 30, are integrated in the carrier plate 34. There are no pipelines. The carrier plate 34 is therefore the fluid housing of the pressure regulator 10.

[0064] Figure 3 A further exploded view of the pressure regulator 10 is shown. Here, the fluid inlet 20 in the carrier plate 34 can be seen.

[0065] Figure 4 A detailed view of the carrier plate 34 of the pressure regulator 10 is shown. In this view, the seat 52 for the regulating valve 24, the fluid connection 54 to the pressure sensor 26 and the seat 56 for the exhaust valve 32 can be seen.

[0066] exist Figure 4 and 5 It becomes clear that all fluid channels 18, 30 and fluid terminals, namely the fluid input end 20, the fluid output end 22, the base 52 for the regulating valve, the fluid connection mechanism 54 to the pressure sensor and the base 56 for the exhaust valve are integrated in the carrier plate 34.

[0067] When the exhaust valve 32 is mounted on the carrier plate 34 , the bypass channel 30 branching off from the main fluid channel 18 opens with its outlet 58 into the inlet of the exhaust valve 32 .

[0068] At the outlet of the exhaust valve 32, an inlet 60 is connected in a further channel section 62, which extends to the exhaust opening 37. The channel section 62 is associated with the bypass channel 30. In other words, the bypass channel 30 is interrupted by the exhaust valve 32. If no exhaust valve 32 is provided, the bypass channel 30 extends continuously to the exhaust opening 37.

[0069] In addition, Figure 4 The fluid input 20 can be seen in FIG.

[0070] Figure 5 A longitudinal section through the carrier plate 34 is shown. The course of the main fluid channel 18 is particularly visible in this view.

[0071] exist Figure 5 A bypass channel 30 can also be seen.

[0072] Figure 6 A side view of the pressure regulator 10 is shown. The housing cover 36 is shown in the position in which it is mounted on the carrier plate 34 .

[0073] Figure 7 Shown along Figure 6 The line AA in FIG. 1 passes through a partial cross section of the pressure regulator 10 .

[0074] Figure 8 A diagram is shown for illustrating the pressure fluctuations in the container 14 by means of a pressure regulator.

[0075] exist Figure 8 In FIG. 1 , the pressure in Pa is plotted on the vertical axis shown on the left. The pressure values ​​are illustrated here by means of squares.

[0076] The right vertical axis shows the opening state of a valve 16 connected downstream of the container 14, wherein the valve 16 is completely closed at 0 and completely open at 100. The opening state of the valve 16 is illustrated in the diagram by means of triangles.

[0077] The time in seconds is plotted on the vertical axis.

[0078] In section a, pressure fluctuations when using a pressure regulator according to the prior art are illustrated.

[0079] In section b, the diagram illustrates the use of Figures 1 to 7 The bypass channel 30 of the pressure regulator 10 has a flow cross section of 10% of the maximum flow cross section of the main fluid channel 18 in the illustrated example.

[0080] It is clear here that the pressure fluctuations when using the pressure regulator 10 according to the invention with the bypass channel 30 are significantly smaller than when using a pressure regulator according to the prior art without the bypass channel.

[0081] The regulated pressure in the container 14 should be 3500 Pa, for example.

[0082] If the valve 16 is open, liquid flows out of the container 14 and the pressure in the container must be readjusted by means of the pressure regulator 10. The smaller the pressure fluctuations that occur in this process, the higher the metering accuracy is possible.

[0083] When using a conventional pressure regulator, the pressure fluctuates between approximately 3200 Pa and 3800 Pa (see section a). When using the pressure regulator 10 according to the invention with the bypass channel 30 , the pressure fluctuations are significantly smaller and in particular are less than 50 Pa (see section b).

Claims

1. A pressure regulator (10) for setting the pressure in a container (14) connected downstream of the pressure regulator and connected to the fluid thereof, wherein the pressure regulator (10) comprises: a main fluid channel (18) having a fluid input end (20) and a fluid output end (22) leading to the container (14); and a regulating valve (24) for setting the fluid pressure at the fluid output end (22), wherein a bypass channel (30) is branched from the main fluid channel (18) downstream of the regulating valve (24), and the main fluid channel (18) can be vented via the bypass channel, and wherein the flow cross section of the bypass channel (30) is smaller than the maximum flow cross section of the main fluid channel (18), The maximum flow cross section of the bypass channel (30) is between 0.1% and 10% of the maximum flow cross section of the main fluid channel (18).

2. The pressure regulator (10) according to claim 1, It is characterized in that The pressure regulator (10) has an electromagnetically actuated vent valve (32), wherein the flow cross section of the bypass channel (30) can be adjusted by means of the vent valve (32).

3. The pressure regulator (10) according to claim 1 or 2, It is characterized in that The pressure regulator (10) has a control unit for controlling the regulating valve (24), wherein the control unit is designed to set the output pressure at the fluid output end (22) to a desired value by correspondingly controlling the regulating valve (24).

4. The pressure regulator (10) according to claim 1 or 2, It is characterized in that The pressure regulator (10) comprises a pressure sensor (26) which is arranged downstream of the regulating valve (24) and is fluidically connected to the main fluid channel (18) so as to measure the actual pressure in the main fluid channel (18) downstream of the regulating valve (24).

5. The pressure regulator (10) according to claim 4, It is characterized in that The pressure regulator (10) has a control unit for controlling the regulating valve (24), wherein the control unit is designed to send an actual pressure measured by the pressure sensor (26) as an input signal to the regulating valve (24).

6. The pressure regulator (10) according to claim 1 or 2, It is characterized in that The pressure regulator (10) comprises a carrier plate (34) in which the main fluid channel (18) extends, and a housing cover (36) mounted on the carrier plate, wherein the housing cover (36) and the carrier plate (34) delimit an electronics space (38) of the pressure regulator (10).

7. The pressure regulator (10) according to claim 6, It is characterized in that Electrical connections (44, 46) of the pressure regulator (10) are arranged on the housing cover (36).

8. The pressure regulator (10) according to claim 1 or 2, It is characterized in that The pressure regulator (10) is constructed as a pipeline-free system.

9. The pressure regulator (10) according to claim 2, It is characterized in that The exhaust valve (32) is designed as a regulating valve.

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