Fluid measuring or fluid control device

Abstract

The invention relates to a fluid measuring or fluid control device having a housing (12), the housing parts (18, 20) of which are fastened to one another by at least one screw joint (40), in which a screw (38) engages through an opening (38) in a peripheral wall (28) of a first housing part (18) and is screwed into a threaded opening (34) in a second housing part (20). An elastic seal (48) is arranged between the housing parts (18, 20). The first housing part (18) has a first resting surface (42) and the second housing part (20) has a second resting surface, both of which are in circumferential contact with the seal (48). The edge of the screw shank and the opening (30) have mating frustoconical surfaces, which are oriented such that when the screw (38) is screwed into the threaded opening (34), the second housing part (20) is displaced in the direction of the first housing part (18) and the resting surfaces (42) come into contact with the seal (48).

Description

Technical Field

[0001] This invention relates to a fluid measurement or fluid control device. Background Technology

[0002] In many installation scenarios, it is necessary to protect devices containing electronic components from environmental factors such as splashing water. For example, the goal is often to achieve protection against dust and water jets from any angle, according to an IP65 protection rating, or even protection against temporary immersion, according to an IP67 protection rating. Summary of the Invention

[0003] The purpose of this invention is to provide a compact fluid measurement or fluid control device with a sealed housing.

[0004] This objective is achieved by a fluid measurement or control device having a housing comprising: a first housing portion and a second housing portion fastened to each other by at least one screw-in connector including a screw having a shank and a head; an opening in the peripheral wall of the first housing portion through which the screw shank engages; and a threaded opening in the second housing portion receiving the screw shank. An elastic seal having an outer circumferential edge region is arranged between the housing portions. The first housing portion has a first resting surface and the second housing portion has a second resting surface, wherein, in the unassembled initial position, one of the housing portions rests its resting surface against the seal. The edges of the screw shank and the opening have mating truncated conical surfaces. In the initial position, the openings in the peripheral wall and the threaded openings are radially offset relative to each other about their central axis, and the truncated conical surface is oriented such that when the screw is screwed in, the truncated conical surface causes the two housing parts to be laterally displaced relative to each other, such that the resting surface presses against the seal and causes the seal to elastically deform.

[0005] The truncated conical surfaces slide against each other, causing the second housing portion to shift along a displacement path in the direction toward the first housing portion when the screw is screwed into the threaded opening. When the screw-on connector is tightened, the second housing portion is pulled toward the first housing portion by sliding against each other through the truncated conical surfaces, thus providing sufficient clamping force for a sealing connection between the two housing portions in the fully tightened position of the screw-on connector.

[0006] In the fully tightened position, the truncated conical surface on the screw shank and the truncated conical surface on the edge of the opening rest against each other in a planar manner or at least along a line over the entire perimeter.

[0007] Advantageously, the two resting surfaces rest on opposite sides of the seal to form at least an outer circumferential line contact around the longitudinal axis of the housing, so as to achieve a seal over the entire periphery of the housing.

[0008] The displacement path of the second housing portion relative to the first housing portion until the screw-on connector reaches its fully tightened position is determined by the length and angle of the truncated conical surface on the screw shank or the edge of the opening. A distance of approximately 1 mm to 3 mm can be specifically selected as the displacement path.

[0009] The angle of the truncated conical surface can be, for example, about 30° relative to the longitudinal axis of the screw or opening, wherein the two truncated conical surfaces should have the same angle of inclination.

[0010] The screw-on connector can be easily configured to always reach, but never exceed, the fully tightened position, thus ensuring the same clamping force for each tightening of the screw-on connector. Therefore, the clamping force is reproducible, which allows the housing to be opened and closed multiple times for tasks such as maintenance.

[0011] In a preferred embodiment, the housing is generally cylindrical, particularly approximating a cuboid, and the screw shank extends perpendicular to the longitudinal axis of the housing, while the displacement path is parallel to the longitudinal axis.

[0012] In order to install the two housing parts to each other, the second housing part is positioned on the first housing part in an initial position in which the truncated conical surface of the screw on the side facing the second housing part is preferably in contact with the truncated conical surface of the opening, but is still spaced apart from the truncated conical surface of the opening on the side facing away from the second housing part.

[0013] In this position, the screw passes through the opening and is inserted and screwed into the threaded opening.

[0014] When the screw is tightened to the fully tightened position, and during the resulting displacement of the second housing portion toward the first housing portion, the distance between the truncated conical surface of the screw and the truncated conical surface of the opening on the side away from the second housing decreases until the two truncated conical surfaces come into contact with each other in a circumferential manner.

[0015] In the fitted position, the opening and the threaded opening are not coaxially aligned; instead, the center of the opening is offset from the center of the threaded opening along the longitudinal axis of the housing in a direction away from the second component. However, in the fully tightened position, the opening and the threaded opening are coaxially aligned.

[0016] The outer contour of the edge region of the seal should be adapted to the cross-section of the housing; for example, it should be a rectangular contour for a cuboid housing.

[0017] Flat seals, O-ring seals, and molded seals made of suitable sealing materials and special elastomers can be selected as seals.

[0018] Preferably, the seal undergoes reversible deformation, allowing the housing to be opened several times and then closed again in a sealed manner.

[0019] The first resting surface on the first housing portion is, for example, an outer circumferential protrusion that engages with the seal in the fully tightened position of the screw-on connector. Therefore, when the screw-on connector is tightened, the resting surface can be easily pressed into the seal.

[0020] Therefore, the protrusions should be aligned along the relative directions in which the shell parts are displaced relative to each other, and thus extend specifically along the longitudinal axis of the shell.

[0021] The protrusion may have, for example, a rectangular, rounded, or chamfered cross-section, which allows the protrusion to easily penetrate the seal, so that the material of the seal can easily engage around the protrusion and thus further improve the sealing effect.

[0022] The displacement path of the housing portion from its initial position to its fully tightened position is advantageously greater than the extension range of the protrusion along the displacement direction, allowing the protrusion to engage with the seal in a controlled manner. In this way, the second housing portion can be positioned on the first housing portion without any contact between the seal and the protrusion. The protrusion will not engage with the seal until the screw is tightened.

[0023] The second resting surface on the second housing portion can be, for example, an outer circumferential annular groove into which the seal is inserted. The annular groove particularly has a U-shaped cross-section.

[0024] The seal should have a certain gap in the annular groove to provide space for changes in the cross-sectional shape of the seal due to the impact of force when the screw-on connector is closed.

[0025] For example, the annular groove is configured to be located in the peripheral wall of the first housing portion, adjacent to the outer side of the first housing portion.

[0026] Alternatively, the first resting surface can be constructed as a groove and the second resting surface as a protrusion. Alternatively, protrusions can be used as resting surfaces on both housing parts.

[0027] For example, a recess, specifically a countersunk hole, is provided in the peripheral wall of the first housing portion. This recess is wider than the screw head in the displacement direction, and its size is at least the diameter of the screw head plus the displacement path. Such a recess can be used to countersunk the screw head relative to the surface of the peripheral wall of the first housing portion. Furthermore, a stop portion associated with the fully tightened position of the screw-in connector can be formed by the remaining portion of the screw head located at the bottom of the recess.

[0028] The distance between the first resting surface and the seal can be easily specified by selecting the distance between the threaded opening and the seal or the annular groove forming the second resting surface.

[0029] Preferably, the truncated conical surface on the screw shank is disposed between the screw head and the threaded portion of the screw shank, such that the screw head engages with the threaded portion via the truncated conical surface, and the threaded portion is screwed into the threaded opening.

[0030] Preferably, a plurality of screw-on connectors are provided along the periphery of the first housing portion to obtain a uniform clamping force and thus a good sealing effect between the first housing portion and the second housing portion. For example, a total of four screw-on connectors may be provided, specifically arranged in pairs on both sides of the first housing portion.

[0031] In one possible implementation, a threaded opening in the second housing portion is provided in a fastening block, which extends into the interior of the first housing portion when the second housing portion is initially positioned onto the first housing portion.

[0032] Advantageously, if the two screw-on connectors are arranged opposite to each other on the parallel, wider sides of the first housing portion, the two screw-on connectors can use the same fastening block.

[0033] It is generally advantageous for the screw shank to extend perpendicular to the longitudinal direction of the housing, as this allows for the use of relatively short screws, which reduces costs because, for example, special designs for exceptionally long screws can be omitted.

[0034] In one possible implementation, a seal is provided on the screw head. Preferably, a seal is present in addition to the annular seal between the two housing parts. This seal may be, for example, an O-ring surrounding the screw shank and may be received in a groove on the underside of the screw head. This allows for a double seal between the two housing parts relative to each other, sealing the opening for the screw in addition to the edges of the two housing parts.

[0035] An additional countersunk hole can be provided, which is adjacent to the truncated conical surface of the opening and accommodates the excess sealing volume of the seal on the screw head.

[0036] Typically, a multi-level recess can be formed around the opening on the peripheral wall of the first housing portion, thereby first achieving a truncated conical surface on the edge of the opening in a radial direction from the inside out, then achieving a first countersunk hole for the O-ring, and then achieving a second countersunk hole to accommodate the screw head.

[0037] For example, the first housing portion is the housing body, while the second housing portion is the cover, which encloses the housing body to isolate it from the environment. The first housing portion can be manufactured as an extruded profile. The second housing portion can be, for example, milled or die-cast.

[0038] The threaded opening extends specifically parallel to the cover surface of the second housing portion, which is perpendicular to the peripheral wall of the first housing portion, and the fastening block is adapted to protrude from the cover surface.

[0039] In a preferred embodiment, the fluid measurement or control device is a mass flow meter based on the Coriolis principle, comprising two fluid connectors and a measuring tube through which fluid flows and which fluidly connects the two fluid connectors to each other. A cover specifically closes the housing on the side opposite to the fluid connectors.

[0040] Where the sealed connection of the two housing parts is advantageous, the housing described herein can certainly be used for any suitable fluid measurement or fluid control device.

[0041] The use of a screw-on connector that causes the second housing portion to move relative to the first housing portion when tightened allows for a simple sealing connection between the two housing portions, as the resting surfaces on both housing portions are in circumferential contact with the seal. Attached Figure Description

[0042] The invention is described in more detail below based on exemplary embodiments and with reference to the accompanying drawings, in which:

[0043] - Figure 1 This is a schematic side view of the fluid measurement or fluid control device according to the present invention;

[0044] - Figure 2 yes Figure 1 A schematic exploded perspective view of a fluid measurement or fluid control device.

[0045] - Figures 3 to 5 yes Figure 1 A schematic cross-sectional view of the screw-in connector of the fluid measurement or fluid control device, taken along line III-III during the tightening of the screw-in connector; and

[0046] - Figure 6 It is a sectional view of the housing of a fluid measurement or fluid control device in the area of ​​the screw-on connector. Detailed Implementation

[0047] Figure 1 and Figure 2 A fluid measurement or fluid control device 10 with a housing 12 is shown.

[0048] In this example, the fluid measurement or fluid control device 10 is a mass flow meter operating according to the Coriolis principle. Therefore, in Figure 1 and Figure 2 Two fluid connectors 14 (both sealed by plugs in the figure) are disposed in the lower part of the housing 12, and the two fluid connectors 14 are fluidly connected by a measuring tube 16. Figure 1 The line is indicated by a dashed line and vibrates in a known manner, which, for example, allows the determination of the fluid flow rate through the measuring tube 16.

[0049] This invention can, of course, also be used in any other type of fluid measurement or fluid control device.

[0050] The housing 12 includes a first housing portion 18 and a second housing portion 20 connected to the first housing portion 18. The first housing portion 18 forms the housing body herein, and the second housing portion 20 forms a cover that encloses the first housing portion 18 to isolate it from the environment.

[0051] The first housing portion 18 is formed herein as a cylindrical member with a rectangular cross-section and defines a longitudinal direction L. Along the longitudinal direction L, the second housing portion 20 is significantly shorter than the first housing portion 18 and has a cover surface 22 oriented perpendicular to the longitudinal direction L and the shape of the cover surface 22 generally corresponds to the cross-section of the first housing portion 18.

[0052] For example, a measuring tube 16 and suitable control and evaluation electronics (not shown) are housed inside the first housing portion 18. A connector 24 for the electronic control circuitry is laterally disposed on one of the narrower sides of the first housing portion 18 and is sealed to isolate it from the environment.

[0053] The first housing portion 18 has two openings 30 on its two relatively wide sides 26 of the peripheral wall 28, which are arranged close to the periphery 32 of the peripheral wall 28. The openings 30 on the two sides 26 are opposite to each other. The peripheral wall 28 extends parallel to the longitudinal direction L and is closed circumferentially relative to the longitudinal direction L.

[0054] For each of the openings 30, a corresponding threaded opening 34 is provided on the second housing portion 20, wherein when the second housing portion 20 is mounted on the first housing portion 18, the openings 30 and the threaded openings 34 overlap (see [reference]). Figures 3 to 5 ).

[0055] In this example, two threaded openings 34 are arranged opposite each other in the fastening block 36, which protrudes vertically from the cover surface 22 of the second housing portion 20 (see [link]). Figure 2 ).

[0056] An opening 30 and a threaded opening 34, together with a screw 38, form a screw-in connector 40. By tightening all screw-in connectors 40, a total of four screw-in connectors in this example, the second housing portion 20 is securely and sealingly connected to the first housing portion 18.

[0057] A first resting surface 42 is formed on the periphery 32, which is a circumferential protrusion extending in the longitudinal direction L in this document. A second resting surface 46 is provided on the cover periphery 44 of the second housing portion 18 facing the periphery 32 of the first housing portion 18, which is in the form of an outer circumferential annular groove opposite to the protrusion in this document.

[0058] A seal 48 is inserted into the annular groove. The seal includes an outer circumferential edge region 49, the outer contour of which corresponds to the perimeter 32.

[0059] In this example, seal 48 is a flat seal adapted to the cross-sectional shape of housing 12 and to components housed within housing 12 (see [link to example]). Figure 2 ).

[0060] Of course, a protrusion can be provided on the second housing portion 20 and an annular groove can be provided on the first housing portion 18, as long as each housing portion is provided with a resting surface 42, 46 to achieve circumferential linear or planar contact with the seal 48.

[0061] The screw 38 includes a screw head 50 and a screw shank 52. The free end of the screw shank 52 is provided with a threaded portion 54 that is adapted to the thread of the threaded opening 34 and can be screwed into the threaded opening 34.

[0062] Between the screw head 50 and the threaded portion 54, the screw 38 includes a truncated conical surface 56 that widens in the direction toward the screw head 50. Here, the diameter of the end 58 of the truncated conical surface 56 away from the screw head is approximately equal to the diameter of the threaded portion 54.

[0063] The opening 30 is completely guided through the peripheral wall 28.

[0064] Figure 6A cross-section through the peripheral wall 28 in the region of opening 30 is shown. In the example shown here, when viewed from inside the housing, the first portion 60 of the edge 62 of opening 30 is cylindrical, with a diameter only slightly larger than the diameter of the threaded portion 54 of screw 38. The threaded portion 54 abuts a truncated conical surface 64 that widens toward the outside of the housing. The other, wider end of the truncated conical surface 64 is surrounded by a first countersunk hole 66, which in turn is surrounded by a second countersunk hole 68 having a shallower depth (relative to the outside of the housing).

[0065] The inclined surfaces of the two truncated conical surfaces 56 and 64 on the screw shank 52 and on the edge 62 of the opening 30 have the same inclination, for example, relative to the longitudinal axis L of the screw shank 52. S Or the longitudinal axis of opening 30 It is approximately 30°.

[0066] The truncated conical surface 56 on the screw rod 52 is significantly longer than the truncated conical surface 64 on the edge 62 of the opening 30, for example, by 3 to 10 times.

[0067] In this example, a second annular groove 72 is also provided on the bottom side 70 of the screw head 50 facing the screw shank, and a second seal 74—in this case an O-ring—is inserted into the second annular groove 72.

[0068] In order to connect the second housing portion 20 to the first housing portion 18, Figure 3 In the initial position shown, the second housing portion 20 is placed on the first housing portion 18, and for each screw-in connector 40, a screw 38 is inserted through one of the openings 30 into the threaded opening 34.

[0069] In the initial position, the edge of the screw head 50 near the second housing portion 20 is positioned relative to the longitudinal direction L of the screw shank 52. S Located outside the second countersunk hole 68, but flush with the edge 76 of the second countersunk hole 68 facing the second housing portion 20 in the longitudinal direction L relative to the housing 12 (see...). Figure 3 ).

[0070] The truncated conical surface 56 on the screw shank 52 contacts the truncated conical surface 64 on the edge 62 of the opening 30, but only in the region facing the second housing portion 20. On the opposite side, the truncated conical surface 56 on the screw shank 52 is spaced apart from the truncated conical surface 64 on the opening 30.

[0071] The central axis of screw rod 52, i.e., the longitudinal axis L S With the central axis of opening 30, i.e., the longitudinal axis They are parallel to each other, but radially offset when viewed along the longitudinal direction L of the housing 12, with the longitudinal axis L of the screw rod 52 being parallel to each other. S The screw is offset in the direction toward the second housing portion 20. This offset also corresponds to the relative displacement path d of housing portions 18 and 20 relative to each other. The screw shank 52 is, of course, coaxial with the threaded opening 34, since the screw shank 52 is screwed into the threaded opening 34.

[0072] In this position, the seal 48 in the annular groove on the second housing portion 20 does not contact the protrusion on the periphery 32 of the first housing portion 18 or only contacts the protrusion on the periphery 32 of the first housing portion 18, so that the screw 38 can be inserted into the opening 30 and initially screwed into the threaded opening 34 without deforming the seal 48.

[0073] This is achieved by appropriately determining the length of the fastening block 36, or more generally by determining the distance between the threaded opening 34, the resting surfaces 42 and 46, the seal 48, and the opening 30.

[0074] If the screw 38 is further tightened, that is, if the screw 38 is further screwed into the threaded opening 34, the truncated conical surfaces 56, 64 on the screw shank 52 and on the edge 62 of the opening 30 slide against each other, thereby causing the housing portions 18, 20 to shift laterally relative to each other, and the second housing portion 20 moves closer to the first housing portion 18 along the longitudinal direction L in the direction of displacement V. This is in Figure 4 As shown in the image.

[0075] As a result, the truncated conical surface 56 on the screw shank 52 moves further toward the peripheral wall 28 of the first housing portion 18, causing the screw head 50 to begin to sink into the second countersunk hole 68.

[0076] The first resting surface 42, i.e. the protrusion here, is pressed into the seal 48 by the tension applied by the screw 38 along the longitudinal direction L to the fastening block 36 and by the fastening block to the entire second housing portion 20.

[0077] Furthermore, the material of the second seal 74 below the screw head 50 elastically deforms and unfolds in the first countersunk hole 66.

[0078] This movement continues until screw 38, and therefore screw-in connector 40, has reached its fully tightened position, where further tightening of screw 38 is no longer possible because the two truncated conical surfaces 56, 64 are placed flat against each other. In this example, the bottom side 70 of screw head 50 also rests against the bottom of second countersunk hole 68, which serves as a stop and thus, in a sense, the endpoint of the tightening movement. The two housing parts 18 and 20 have traveled a complete displacement path d toward each other, such that the longitudinal axis L is now... S , They coincide on a straight line. Figure 5 The image shows the fully tightened position.

[0079] The displacement path d is determined in this paper by the length of the truncated conical surface 56 on the screw rod 52, while the truncated conical surface 64 on the edge 62 of the opening 30 serves as a guide.

[0080] As can be understood from these specifications, the minimum diameter of the opening 30 in this document is greater than the diameter of the end 58 of the truncated conical surface 56 of the screw 38 that is furthest from the screw head.

[0081] The displacement path d depends on the longitudinal axis L of the truncated conical surface 56 relative to the screw rod 52. S The cosine of the angle, and therefore always shorter than the axial length of the truncated conical surface 56.

[0082] The length of the protrusion engaging in the seal 48 is chosen to be slightly shorter than the displacement path d, so that the second housing portion 20 can be mounted on the first housing portion 18 in a mating position without being obstructed by the protrusion of the first resting surface 42.

[0083] In this way, all the screw-on connectors 40 on the housing 12 are tightened to their fully tightened position.

[0084] This arrangement ensures a dustproof and waterproof connection between the two housing parts 18 and 20 that meets the requirements of IP65 and even IP67 protection levels.

[0085] To open housing 12, loosen all screw connections 40 and remove screws 38, allowing the second housing portion 20 to be removed from the first housing portion 18. The two housing portions 18, 20 can be reconnected as described above, and the seal 48 must be replaced if necessary.

Claims

1. A fluid measurement or fluid control device having a housing (12), the housing (12) comprising: A first housing portion (18) and a second housing portion (20) are fastened to each other by at least one screw-in connector (40), the screw-in connector (40) comprising a screw (38) having a screw shank (52) and a screw head (50); an opening (30) in the peripheral wall (28) of the first housing portion (18) through which the screw shank (52) engages; and a threaded opening (34) in the second housing portion (20) receiving the screw shank (52), wherein an elastic seal (48) having an outer circumferential edge region (49) is arranged between the first housing portion (18) and the second housing portion (20), and the first housing portion (18) has a first resting surface (42) and the second housing portion (20) has a second resting surface (46), wherein In the unassembled initial position, the first housing portion (18) rests its first resting surface (42) or the second housing portion (20) rests its second resting surface (46) against the seal (48), and wherein the screw shank (52) and the edge (62) of the opening (30) have mating truncated conical surfaces (56, 64), wherein, in the initial position, the opening (30) and the threaded opening (34) in the peripheral wall (28) are radially offset relative to each other about their central axis, and the truncated conical surfaces (56, 64) are oriented such that, upon screwing, the truncated conical surfaces (56, 64) cause the first housing portion (18) and the second housing portion (20) to laterally displace relative to each other, such that the first resting surface (42) or the second resting surface (46) presses against the seal (48) and causes the seal (48) to elastically deform.

2. The fluid measurement or fluid control device according to claim 1, characterized in that, The first resting surface (42) on the first housing portion (18) is an outer circumferential protrusion that engages in the seal (48) in the fully tightened position of the screw-on connector (40).

3. The fluid measurement or fluid control device according to claim 2, characterized in that, The displacement path (d) of the first housing portion (18) and the second housing portion (20) from the initial position to the fully tightened position is greater than the extension range of the protrusion along the displacement direction (L).

4. The fluid measurement or fluid control device according to any one of claims 1 to 3, characterized in that, The second resting surface (46) on the second housing portion (20) is an outer circumferential annular groove, and the seal (48) is inserted into the outer circumferential annular groove.

5. The fluid measurement or fluid control device according to any one of claims 1 to 3, characterized in that, The truncated conical surface (56) on the screw shank (52) is arranged between the screw head (50) of the screw (38) and the threaded portion (54) on the screw shank (52).

6. The fluid measurement or fluid control device according to any one of claims 1 to 3, characterized in that, A plurality of screw-on connectors (40) are provided along the periphery of the first housing portion (18).

7. The fluid measurement or fluid control device according to any one of claims 1 to 3, characterized in that, The threaded opening (34) in the second housing portion (20) is provided in the fastening block (36), which extends into the interior of the first housing portion (18).

8. The fluid measurement or fluid control device according to any one of claims 1 to 3, characterized in that, A seal (74) is provided on the screw (38) at the lower end of the screw head (50).

9. The fluid measurement or fluid control device according to any one of claims 1 to 3, characterized in that, The first housing portion (18) is the housing body, and the second housing portion (20) is a cover that encloses the housing body to isolate it from the environment.

10. The fluid measurement or fluid control device according to any one of claims 1 to 3, characterized in that, The fluid measurement or fluid control device (10) is part of a mass flow meter based on the Coriolis principle, which includes two fluid connectors (14) and a measuring tube (16) through which fluid flows and through which the two fluid connectors (14) are fluidly connected to each other.

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