Method for Producing a Bourdon Tube Pressure Gauge

Abstract

The invention relates to a method for producing a Bourdon tube pressure gauge 1, comprising at least a housing 2, a Bourdon tube 3 and a process carrier 5, wherein the process medium enters the Bourdon tube 3 via a fluid channel starting from the process carrier 5 and the process carrier 5 is constructed in two parts, wherein a first part is connected to the Bourdon tube 3 as a spring carrier 4 and a second part serves as a connecting element 18 and both parts are joined and connected in the housing 2. In order to enable a low bearing retention, it is provided for the manufacture of a Bourdon tube pressure gauge 1 that the connecting element 18 and/or the spring carrier 4 has a round shoulder 17, 23 and the shoulder 17, 23 is inserted into a radial bore 7 of the housing, wherein first a connection is made between the shoulder 17, 23 of the connecting element 18 and spring carrier 4 and then a connection of the shoulder 17, 23 to the housing 2. Thus, it is possible to provide different connecting elements 18 as well as spring supports 4, which are only assembled and welded together according to the customer's requirements, whereby these are accommodated in a housing 2 and welding to the housing 2 also takes place, so that the Bourdon tube pressure gauge 1 to be finished can be assembled individually in each case.

Claims

1. Method for producing a Bourdon tube pressure gauge (1), comprising at least one housing (2, 41), a Bourdon tube (3) and a process carrier (5), the process medium being introduced into the Bourdon tube (3) via a fluid channel starting from the process carrier (5), and the process carrier (5) being designed in two parts, a first part being connected to the Bourdon tube (3) as a spring carrier (4) and a second part serving as a connecting element (18), and the two parts being joined together and connected in the housing (2, 41), characterized in that the connecting element (18) and/or the spring carrier (4) have a round shoulder (17, 23) and the shoulder (17, 23) is introduced into a radial bore (7) of the housing (2), a connection first being produced between the shoulder (17, 23) of the connecting element (18) and spring carrier (4) and then a connection of a shoulder (17, 23) to the housing (2, 41).

2. Method according to claim 1, characterized in that the two joined parts, namely the spring carrier (4) and the connecting element (18), are axially displaceable and rotatable relative to the bore (7) of the housing (2, 41) and a connection with the housing (2, 41) takes place after the alignment of the spring carrier (4) with the Bourdon tube (3) relative to the housing (2, 41) both in the plane of the housing and in the distance of the connecting element (18) from the housing (2, 41).

3. Method according to claim 1, characterized in that the spring carrier (4) with Bourdon tube (3) is aligned parallel to the plane of the housing, and/or that the spring carrier (4) and the connecting element (18) are aligned in the axial direction relative to the housing (2,41).

4. Method according to claim 1, characterized in that one of the shoulders (17, 23) has a recess (26) and the corresponding shoulder (17, 23) has an annular protrusion (27).

5. Method according to claim 1, characterized in that the shoulders (17, 23) have a bore opening into the spring carrier (4) and the Bourdon tube (3), and/or in that at least one shoulder (17, 23) has a length of more than 5 mm.

6. Method according to claim 1, characterized in that a choke or a filter with a bore (7, 12, 15, 24, 31, 32) of 0.1 mm, 0.2 mm or 0.3 mm is inserted into the bore (30, 31) of the process carrier (5) or the connecting element (18) before the welding of both parts.

7. Bourdon tube pressure gauge (1) according to method claim 1, consisting of at least one housing (2, 41), a Bourdon tube (3) and a process carrier (5), the process carrier (5) being designed in two parts, a first part being connected to the Bourdon tube (3) as a spring carrier (4) and a second part serving as a connecting element (18), and the two parts being joined together and connected in and to the housing (2, 41), characterized in that the connecting element (18) and/or the spring carrier (4) has a round shoulder (17, 23) and the shoulder (17, 23) can be inserted into a radial bore (7) of the housing (2, 41), there being a connection between the shoulder (17, 23) of the connecting element (18) and spring carrier (4) and a connection of a shoulder (17, 23) to the housing (2, 41), the spring carrier (4) with Bourdon tube (3) being aligned parallel to the plane of the housing and the spring carrier (4) and the connecting element (18) being aligned in the axial direction relative to the housing (2, 41).

8. Bourdon tube pressure gauge (1) according to claim 7, characterized in that all connections are made by laser welding and/or that one of the shoulders has a recess (26) and the corresponding shoulder (17, 23) has an annular protrusion (27).

9. Bourdon tube pressure gauge (1) according to claim 7, characterized in that the shoulder (17, 23) has a bore (30, 31) opening into the spring carrier (4) and the Bourdon tube (3), and/or in that at least one shoulder (17, 23) has a length of more than 5 mm.

10. Bourdon tube pressure gauge (1) according to claim 7, characterized in that a choke or a filter with a bore of 0.1 mm, 0.2 mm or 0.3 mm is inserted into the bore (30, 31) of the process carrier (5) or of the connecting element (18), and/or in that the process carrier (5) has a bore for filling with a viscous liquid.

11. Bourdon tube pressure gauge (1) according to claim 7, characterized in that the Bourdon tube pressure gauge (1) is equipped with a second electronic measuring unit (46) which is provided with a current output of 4 to 20 mA for connection to a monitoring device.

12. Bourdon tube pressure gauge (1) according to claim 7, characterized in that the electronic measuring system is metallically encapsulated and thus waterproof and splashproof, and/or that the electronic measuring system consists of an encoder.

13. Bourdon tube pressure gauge (1) according to claim 7, characterized in that the encoder system can be used for plate springs, Bourdon tubes, capsule springs, absolute measuring instruments, differential pressure measuring instruments, mechanical force transducers, mechanical temperature measuring instruments and rail vehicles.

14. Bourdon tube pressure gauge (1) according to claim 7, characterized in that the pointer shaft of the measuring unit (46) is extended at the rear and has a magnet receptacle for the encoder system.

15. Bourdon tube pressure gauge (1) according to claim 7, characterized in that a magnet is arranged on the extended pointer shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The invention is further explained with reference to the figures.

[0030] It shows

[0031] FIG. 1 the individual components of a Bourdon tube pressure gauge in a perspective exploded view,

[0032] FIG. 2 the assembled Bourdon tube pressure gauge in a perspective view,

[0033] FIG. 3 the Bourdon tube pressure gauge according to FIG. 2 in a sectional top view, with a cut in the plane of the housing and a process carrier,

[0034] FIG. 4 the Bourdon tube pressure gauge according to FIG. 2 in a perspective sectional view, with a cut perpendicular to the plane of the housing and a process carrier

[0035] FIG. 5 the Bourdon tube pressure gauge according to FIG. 1 in an intermediate step during production and

[0036] FIG. 6 the housing with flanged electronic measuring system.in a perspective, partly cut view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] FIG. 1 shows a perspective exploded view of a Bourdon tube pressure gauge 1, consisting of a housing 2, a Bourdon tube 3 and a process carrier 5, which consists of a spring carrier 4 and a connecting element 18.

[0038] The housing 2 consists of a round pot-shaped housing part with a bottom 6 and an open front view, which can be closed by means of a cover (not shown) in the form of a frame and a glass pane. The housing 2 has a first bore 7 for the process carrier 5 and a second step bore 8 for a possible evacuation process. The step bore 8 is closed by a plug which is not shown, while the bore 7 is completely sealed airtight after insertion of the process carrier 5 with subsequent welding.

[0039] The Bourdon tube 3 has an approximately rectangular cross-section with rounded narrow sides 9, 10. A first end of the Bourdon tube 3 is provided with a connection plate 11, which has a bore 12 to allow the process medium to enter the Bourdon tube 3. The process medium is supplied via the process carrier 5 and the spring carrier 4. The second end of the Bourdon tube 3 is provided with an end plate 13, on which an angle plate 14 with a bore 15 is also provided, the measuring unit, which is not shown, being connected via the bore 15. In this way, a change in the curvature of the Bourdon tube 3 can be detected and transmitted via the measuring mechanism to a pointer (not shown).

[0040] The spring carrier 4 has an approximately cuboid shape, but may deviate from this in individual cases. A beveled surface 16 serves for contact and for welding with the connection plate 11 of the Bourdon tube 3. In addition, the spring carrier 4 is provided with an annular shoulder 17, which is provided for connection with the connecting element 18. A bore extends through both the connecting element 18 and the spring carrier 4, as can be seen, for example, from FIGS. 3 and 4. A hexagonal section 20 of the connecting element 18 has outer surfaces 21 for screwing the connecting element 18 into an existing pipeline by means of an open-end wrench. A round projection 22 of the connecting element 18 is provided with a thread, which can be designed with different threads according to the customer's requirements, which is provided for a fixed screw-in connection with the pipelines. Above the hexagonal section 20, there is an annular shoulder 23 in which a bore 24 is located. As can be seen from FIGS. 3 and 4, the bore 24 extends through the entire connecting element 18 and serves as a supply of the process medium. The bore 24 opens into the spring carrier 4, which also has a bore, so that there is a direct connection to the Bourdon tube 3. Both the spring carrier 4 and the connecting element 18 are provided with an annular shoulder 17, 23, which have approximately the same diameter.

[0041] The shoulder 23 of the connecting element 18 also has a recess 26 which corresponds with a protrusion 27 of the spring carrier 4 below. The protrusion is not visible in this illustration, but it engages precisely in the annular recess 26 during assembly. After joining the connecting element 18 and the spring carrier 4, the connecting element 18 and the spring carrier 4 are welded together to form a one-piece assembly.

[0042] This method was chosen in the present case so that an already completed spring carrier 4 with Bourdon spring 3 can be connected to any desired connection in the form of the connecting element 18. For this purpose, the connecting element 18 has a threaded connection which may have a different diameter depending on the application, but which is generally standardized. By subsequently connecting the connecting element 18 and spring carrier 4, an individual combination can thus be produced when an order is placed, which can significantly reduce the amount of stock held. In this case, the welding of connecting element 18 and spring carrier 4 is not carried out until the annular shoulder 17 of the spring carrier has been passed through the bore 7 of the housing 2. After welding has taken place, there is a firm connection between process carrier 5 and spring carrier 4 with Bourdon spring 3. Welding to the housing 2 then takes place, whereby alignment of the Bourdon spring 3 within the housing 2 is possible both in the plane and in a coaxial position to the housing 2. For this purpose, the shoulder 17 of the spring carrier 4 and the shoulder 23 of the connecting element 18 are used, which offer the possibility of rotating and displacing the connecting element 18 relative to the housing 2 together with the spring carrier 4 and the Bourdon spring 3. After the desired position has been determined, either the annular shoulder 17 of the spring carrier 4 or the annular recess 25 of the connecting element 18 is welded to the housing 2. The advantage of this subsequent welding is that a desired alignment of the Bourdon spring can be made within the housing, whereby the respective components of a Bourdon tube manometer 1 are for the most part prefabricated and individually combined and welded with a connecting element 18 in accordance with the customer's wishes, so that stockkeeping can be significantly reduced.

[0043] FIG. 2 shows a perspective view of the pressure gauge 1 after the connecting element 18, 5, spring carrier 4 and Bourdon spring 3 have been joined and welded to the housing 2. As a result of the welding to the shoulder 17 or 23 of the spring carrier or connecting element 18, the housing 2 is completely sealed in the area of the connecting element 18, while the upper step bore 8 must be closed by a plug. The Bourdon spring 3 is inserted centrally inside the housing 2 and is locked by the welding. For this purpose, it is only necessary to install the measuring mechanism in the housing 2 and to fit a lockable cover, so that the Bourdon tube pressure gauge 1 is completed.

[0044] FIG. 3 shows a sectional view of the Bourdon tube pressure gauge 1, with the cut running in the plane of the housing 2 through the connecting element 18. For this reason, the connecting element 18 can be seen with a bore 30, which opens into the spring carrier 4. A further bore 31 is present in the spring carrier 4, so that the process medium to be measured enters the Bourdon spring 3 directly via the bores 30, 31. The Bourdon tube 3 consists of a tube which, in the example shown, has an almost rectangular cross-section with rounded narrow sides 9, 10. The Bourdon tube 3 is also welded to the spring carrier 4 and has at the other end an end plate 13 with an angle plate 14, which has a bore 15 for connection to a measuring unit not shown. In this case, the connection is made purely mechanically so that the movement can be transmitted to the measuring mechanism through the curvature of the Bourdon tube 3, and the pointer movement is realized with a corresponding transmission.

[0045] FIG. 4 shows a further perspective sectional view of the Bourdon tube pressure gauge 1, and this time the section runs perpendicular to the plane of the housing 2 through which the connecting element 18 passes. In this respect, the bore 30 of the process support is visible and the bore 31 of the spring support 4 only through a small incision. From this view, the shape of the Bourdon tube 3 is once again apparent, with an almost rectangular cross-section, the narrow sides 9, 10 being rounded. From this view it can further be seen that the housing 2 is completely flat and closed in the rear area, while in the front area it has a U-shaped recess 32 for closing with a glass-shaped cover, into which, for example, a sealing element can be inserted.

[0046] FIG. 5 shows a perspective view of the Bourdon tube pressure gauge 1 with housing 2, spring carrier 3 with Bourdon spring 3 and the connecting element 18. In this case, the first work step for assembling the Bourdon tube pressure gauge 1 is shown, namely a welding of the spring carrier 4 to the connecting element 18 via a weld seam 33. Once welding has been carried out, which is preferably a laser welding operation, the annular shoulder 17 of the spring carrier 4 and the annular shoulder 23 of the connecting element 18 can thus be displaced within the bore 7 of the housing 2. Likewise, a rotation is possible, so that a centric alignment of the Bourdon spring 3 within the housing 2 can take place, whereby likewise an alignment to the plane of the housing 2 is possible. After the fastening element 18 has been fixed relative to the housing 2, both components can thus be welded together so that the lower bore 7 is not only completely closed, but also offers the possibility of aligning the Bourdon spring 3 by means of the two annular shoulders 17 and 23.

[0047] FIG. 6 shows a partially cut perspective rear view of a pressure gauge 40. The housing 41 with Bourdon spring corresponds largely to the design shown in FIGS. 1 to 5. The housing 41 is closed by a cover 42 provided with a glass pane, the cover 42 being firmly seated on the housing 41 with the aid of a circumferential collar 43. A measuring unit 46 is located in the housing 41. In the rear area of the housing 41, a round flange 47 is formed on the housing 41, which is provided to accommodate an electronic measuring system. The only difference between the measuring unit 46 and known embodiments is that the pointer shaft 44 is extended and fitted at the end with a magnet 45. The magnet 45 thus rotates in proportion to the movement of the pointer shaft 44 and causes a magnetic field change in the electronic measuring system, which can be detected with the aid of magnetic field sensors and thus the angle of rotation of the pointer shaft 44 can be determined. The angle of rotation is converted proportionally into a voltage or current signal, which is forwarded to a monitoring direction via a connector plug 48 located at the end.

[0048] The embodiment thus discloses a pressure gauge 40 having both a mechanical measuring unit 46 and an electronic measuring mechanism.

LIST OF REFERENCE NUMERALS

[0049] 1 Bourdon tube pressure gauge

[0050] 2 Housing

[0051] 3 Bourdon tube

[0052] 4 Spring carrier

[0053] 5 Process carrier

[0054] 6 Bottom

[0055] 7 Bore

[0056] 8 Step bore

[0057] 9 Narrow side

[0058] 10 Narrow side

[0059] 11 Connection plate

[0060] 12 Bore

[0061] 13 End plate

[0062] 14 Angle plate

[0063] 15 Bore

[0064] 16 Surface

[0065] 17 Shoulder

[0066] 18 Connecting element

[0067] 20 Hexagonal section

[0068] 21 Outer surface

[0069] 22 Projection/threaded projection

[0070] 23 Shoulder

[0071] 24 Bore

[0072] 25 Annular recess

[0073] 26 Recess

[0074] 27 Protrusion

[0075] 31 Bore

[0076] 32 Recess

[0077] 33 Weld seam

[0078] 40 Pressure gauge

[0079] 41 Housing

[0080] 42 Cover

[0081] 43 Collar

[0082] 44 Pointer shaft

[0083] 45 Magnet

[0084] 46 Measuring unit

[0085] 47 Flange

[0086] 48 Connector plug