Assembly of a sensor

Abstract

An assembly of a sensor has a cover (30) which is substantially designed in the shape of a hollow cylinder and which is closed at a first end. A coil (20) is arranged at a first end in the cover (30). A substantially hollow cylindrical insert (10) is inserted into the cover (30) such that a first end thereof faces the coil (20) and a second end thereof protrudes from the cover (30). The insert (10) is internally provided with at least one latch hook (11) which is designed to be loaded with a spring orthogonally to the longitudinal axis of the insert (10). The sensor has the assembly and a circuit board (50). The circuit board (50) extends through the second end of the insert (10) into the assembly and is locked with the latch hook (11).

Description

Technical Field

[0001] The invention relates to a sensor component and a sensor having the component. Background Art

[0002] A sensor, such as an inductive distance sensor, has a coil that serves as a transmitting and / or receiving coil. It is mounted in a housing together with a circuit board and is electrically connected to the housing via a solder connection. To prevent moisture intrusion, the interior of the housing is filled with a filling material. This can be, for example, polyurethane foam or casting resin. This material also prevents the circuit board in the housing from moving relative to the coil, which could damage the solder connection. However, a disadvantage of using such foams or resins is that these substances are harmful to the environment.

[0003] It is therefore an object of the present invention to provide a sensor that does not require internal foam or resin filling to operate. It is another object of the present invention to provide an assembly with which such a sensor can be installed quickly and cost-effectively. Summary of the invention

[0004] In a first aspect of the invention, this object is solved by a sensor assembly. The assembly comprises a cover, which is substantially designed in the shape of a hollow cylinder, preferably in the shape of a hollow cylinder. The cover has a first end and a second end and is closed at the first end. The coil is arranged at the first end in the cover. The coil can be arranged on or in a carrier material in particular. In particular, it is designed as a printed coil. In addition, the coil can be arranged on or in a carrier material in particular together with one or more additional coils. The coil can be designed as a transmitting coil, a receiving coil or a transmitting and receiving coil. In addition, the assembly comprises an insert, preferably in the shape of a hollow cylinder, substantially in the shape of a hollow cylinder. The insert has a first end and a second end. It is inserted into the cover in such a way that its first end faces the coil and its second end protrudes from the cover. The insert has at least one, preferably two, locking hooks inside. Each locking hook is designed to be loaded with a spring orthogonally to the longitudinal axis of the insert.

[0005] The circuit board can be fixed in a defined position in the assembly by means of a locking hook. When it engages in the cavity of the circuit board, the circuit board remains fixed in position in the assembly without the need for foam or resin as filling material to prevent subsequent changes in the position of the circuit board relative to the assembly and the coil. Furthermore, the advantage of designing the cover, coil and insert as a universal assembly is that it can be used as a stock pre-assembled set for subsequent fast and flexible assembly of different sensor types. The sensor type is then determined by the type of circuit board that is inserted into the assembly and connected to the coil.

[0006] Preferably, the insert has at least three sub-areas in its region arranged in the cover. A first sub-area borders a second sub-area, which borders a third sub-area, which borders the second end of the cover and, if necessary, extends beyond the second end. The outer diameter of the first sub-area is greater than the outer diameter of the second sub-area. The outer diameter of the second sub-area is greater than the outer diameter of the third sub-area. This means that the outer diameter of the sub-areas increases from the open second end of the cover in the direction of its closed first end.

[0007] This embodiment of the partial area can be advantageously used to fix the insert in the lid. For this purpose, the intermediate space between the inner wall of the lid and the second and third partial areas of the insert is preferably filled with adhesive. In this case, since the distance between the third partial area and the inner wall of the lid is relatively large, the third partial area can be used as a distribution chamber for the adhesive. In the second partial area, the distance between the inner wall of the lid and the outer wall of the insert is smaller than the distance in the third partial area, and bonding occurs between the insert and the lid by using a small amount of adhesive. The first partial area is particularly close to the inner wall of the lid, so that it acts as an adhesive brake and prevents the adhesive distributed in the third partial area from spreading outside the third and second partial areas.

[0008] Furthermore, it is preferred that the insert has a fourth partial area located outside the cover. The outer diameter of the fourth partial area is smaller than the outer diameter of the third partial area. The first seal is arranged outside the fourth partial area. It is particularly preferably designed as an O-ring surrounding the fourth partial area. If the assembly is introduced into the sensor housing, the first seal prevents moisture penetrating between the cover and the inner wall of the sensor housing from being able to diffuse further from this end of the sensor housing to the interior of the sensor housing. The adhesive prevents moisture from penetrating into the cover. This ensures that the sensor is sealed in liquid and gaseous media without having to fill the interior of the sensor housing with foam or resin. In this way, a sensor with protection level IP68 in accordance with ISO 20653 can be obtained.

[0009] During the final assembly of the sensor, its circuit board should be positioned in a defined position relative to the coil. In order to achieve this, preferably, an insert is provided with a first positioning element in the form of a protrusion that engages with the coil. In particular, it engages into a cavity in the carrier material of the coil. In this way, the coil is positioned in a defined position relative to the insert. Furthermore, preferably, the insert has a second positioning element in the form of a track. This track is provided to receive a circuit board pushed in through the second end of the insert. In this way, the circuit board is also positioned in a defined position relative to the insert. Due to the fixing of the coil relative to the insert and the fixing of the circuit board relative to the insert, a defined relative position of the circuit board relative to the coil can be achieved.

[0010] In principle, there is still the possibility of incorrectly positioning the circuit board by rotating it by 180° relative to its desired position. In order to exclude this risk, it is further preferred that the insert has a third positioning element at its second end. This is provided for aligning the light source of the circuit board. The circuit boards used in the sensor usually have a light source, for example in the form of an LED, on one side. The third positioning element is designed, for example, as a cavity in the insert and can be used as an optical positioning aid to ensure that the correct orientation of the circuit board is selected from the two possible orientations of the circuit board in the track. In this way, incorrect positioning can be excluded.

[0011] In another aspect of the invention, this object is achieved by a sensor, in particular an inductive sensor, comprising the assembly. The sensor further comprises a circuit board. It extends through the second end of the insert into the assembly and is locked by means of a locking hook. For this purpose, the circuit board particularly has a cavity in which the locking hook engages. The circuit board is immobile in the sensor relative to the assembly and thus relative to the coil.

[0012] Preferably, the sensor has at least one spring-loaded element in electrical contact with the coil and the circuit board. In this way, the circuit board and the coil are electrically connected to each other without the need for a solder connection. In different embodiments of the sensor, the spring-loaded element can be arranged on the circuit board or on the coil. It is arranged specifically by SMT (surface-mount technology). If the circuit board is inserted into the insert of the component during the final assembly of the sensor, the circuit board and the coil will converge so that the spring-loaded element arranged on the circuit board is in contact with the coil, or the spring-loaded element arranged on the coil is in contact with the circuit board. In the process, it partially overcomes its spring force and deflects, thereby firmly leaning against the circuit board or the coil and establishing a firm electrical connection between the circuit board and the coil.

[0013] Embodiments of the spring-loaded element particularly suitable for use in the sensor are selected from the group consisting of a spring contact, an edge connector and a cable clamp.

[0014] For this purpose, the spring contact can be formed in different ways in different embodiments. For example, it can be folded once or multiple times. In the embodiment in which the spring contact is arranged on the circuit board, its contact point with the coil can be located in the plane of the circuit board or above the plane of the circuit board. It can extend from the end of the circuit board facing the coil in the direction of the coil, or it can first extend above the circuit board before contacting the coil. The spring contact can also surround the circuit board by being arranged on one side of the circuit board, protruding from the circuit board in the direction of the coil until the position of contacting the coil, and extending further from there to the opposite side of the circuit board.

[0015] If the spring-loaded element is designed as an edge connector, it is arranged in particular on the carrier material of the coil in such a way that the end of the circuit board can be pushed into the edge connector.

[0016] If the spring-loaded element is designed as a cable clamp (also called a wire clamp), it is arranged on the carrier material of the coil. It can contact the circuit board pushed into the cable clamp from both the top and bottom sides and establish an electrical connection with the circuit board in the area of ​​the surface metal coating on the circuit board.

[0017] The assembly and the circuit board are preferably arranged in a housing, in particular a cylinder. Thus, the assembly closes one end of the housing. The tube seal is arranged in the housing at a second end of the housing. The tube seal has a plug insert which is electrically connected to the circuit board. A second seal is arranged between the tube seal and the inner wall of the housing. It is preferably designed as an O-ring. In this way, the end of the housing opposite to the assembly can also be reliably sealed against the ingress of fluids. Therefore, it is not necessary to fill the interior of the housing with foam or resin. Instead, it is preferred that the circuit board is surrounded by a gas, in particular air. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description.

[0019] Figure 1a An isometric representation of an insert for a sensor according to an exemplary embodiment of the present invention is shown.

[0020] Figure 1b Shown according to Figure 1a Another isometric representation of the insert.

[0021] Figure 1c Shown according to Figure 1a Further isometric representation of the insert in FIG.

[0022] Figure 1d Shown according to Figure 1a A cross-sectional isometric representation of the insert.

[0023] Figure 2 A cross-sectional representation of components of a sensor according to an exemplary embodiment of the present invention is shown.

[0024] Figure 3 Shown according to Figure 2 A cross-sectional representation of an assembly of an insert and an adhesive disposed therein.

[0025] Figure 4 An isometric representation of a coil in an exemplary embodiment of a sensor according to the invention is shown.

[0026] Figure 5A cross-sectional representation of a sensor according to an exemplary embodiment of the present invention is shown.

[0027] Figure 6 An isometric sectional representation shows how a circuit board is introduced into an insert in an exemplary embodiment of a sensor according to the invention.

[0028] Figure 7 The arrangement of a circuit board in an assembly of a sensor according to an exemplary embodiment of the invention is shown in an isometric cross-sectional representation.

[0029] Figure 8a An isometric representation of spring contacts of a sensor according to an exemplary embodiment of the present invention is shown.

[0030] Figure 8b An isometric representation of another spring contact of a sensor according to an exemplary embodiment of the present invention is shown.

[0031] Figure 8c An isometric representation of yet another spring contact of a sensor according to an exemplary embodiment of the present invention is shown.

[0032] Figure 8d An isometric representation of yet another spring contact of a sensor according to an exemplary embodiment of the present invention is shown.

[0033] Figure 8e An isometric representation of yet another spring contact of a sensor according to an exemplary embodiment of the present invention is shown.

[0034] Figure 8f An isometric representation of yet another spring contact of a sensor according to an exemplary embodiment of the present invention is shown.

[0035] Figure 8g An isometric representation of yet another spring contact of a sensor according to an exemplary embodiment of the present invention is shown.

[0036] Fig. 9 An isometric representation of an edge connector of a sensor according to an exemplary embodiment of the present invention is shown.

[0037] Fig.10 An isometric representation of a cable clamp for a sensor according to an exemplary embodiment of the present invention is shown.

[0038] Fig.11 A side view shows how a circuit board is arranged in a cable clamp in a sensor according to an exemplary embodiment of the invention.

[0039] Fig.12 An arrangement of circuit boards in an assembly according to an exemplary embodiment of the invention is shown in an isometric cross-sectional representation. DETAILED DESCRIPTION

[0040] In order to produce a sensor according to an exemplary embodiment of the invention, which is designed, for example, as an inductive sensor, first a component is produced which serves as a pre-assembly set for the later final assembly of the sensor. The component has an insert 10, such as Figure 1a to Figure 1d As shown. The insert 10 is basically designed in the shape of a hollow cylinder. It has two locking hooks 11 inside, which are integral with the insert. The locking hooks 11 are designed to be loaded with springs orthogonally to the longitudinal axis of the insert 10. The insert 10 has a first positioning element 12 in the form of a protrusion at a first end. The opening of the hollow cylinder narrows at its opposite second end, wherein a second positioning element 13 is formed in the form of a track at the narrowing. Looking at the insert 10 from the second end, it has a circular opening, which is widened by the second positioning element at two opposite points. If a plane passes through the track, then the two locking hooks 11 are also located in this plane. The third positioning element 14 further widens the circular opening. This widening is orthogonal to the plane.

[0041] In addition to the insert 10, the assembly also has a coil 20 and a cover 30. The insert 10 is made of plastic. The coil 20 is designed as a printed coil in a circuit board substrate. Its cross section is circular. Similarly, the cover 30 is made of plastic. It has a substantially cylindrical outer contour and is closed at one end (i.e., its first end). The coil 20 is inserted into the cover 30 in a manner that contacts the cover of the first end. The insert 10 is inserted into the cover 30 in a manner that is mounted on the coil 20 and partially protrudes from the cover 30. The insert 10 has four parts 15-19 with different outer diameters. The base 15 contacts the coil 20. The base is bounded by the first part 16, which has the largest outer diameter of all parts. In addition, it engages in the annular circumferential cavity in the cover 30 and fixes the insert 10 in its position. The second part 17, the third part 18 and the fourth part 19 are immediately following the first part 16. The outer diameters of these parts gradually decrease from the first part 16 to the fourth part 19. The base 15, the first portion 16 and the second portion 17 are arranged completely in the cover 30. The third portion 18 is located partly inside the cover 30 and partly outside the cover 30. The fourth portion 19 is arranged completely outside the cover 30.

[0042] In order to permanently connect the insert 10 to the cover 30, the adhesive is filled into the cover 30 through the intermediate space between the inner wall of the cover 30 and the outer wall of the insert 10. Figure 3 As shown, the adhesive thus initially fills the space between the cover 30 and the second part 18, which serves as a dispensing chamber and may have a size of 22.7 mm, for example. 3Below this area of ​​the adhesive 41, it flows further into the intermediate space between the cap 30 and the first part 17. A smaller volume (e.g. 4.8 mm 3 ) is now filled with adhesive 42 and a strong bond is achieved between insert 10 and cap 30. Finally, first portion 16 acts as an adhesive stopper and prevents adhesive 41, 42 from flowing deeper into cap 30.

[0043] Figure 4 The circuit board substrate showing the coil 20 has a cavity 21 on its side. The first positioning element 12 of the insert 10 engages into this cavity 21 so that the coil 20 is positioned in the cover 30 in a defined position relative to the insert 10 .

[0044] Figure 5 A representation of a fully mounted sensor according to an exemplary embodiment of the present invention is shown. A circuit board 50 is pushed into an assembly consisting of an insert 10, a coil 20 and a cover 30. The assembly and the circuit board 50 are arranged together in a cylindrical housing 60, for example made of plastic, so that the cover 30 closes the housing 60 at one end. A tube seal 70 is introduced into the housing 60 from the other end of the housing 60 so that it closes the housing 60 at the other end. A plug insert 71 that is in electrical contact with the circuit board 50 is arranged in the tube seal. The circuit board 50 of the sensor can be connected to an external device via the plug contacts of the plug insert 71. The sensor has a first seal 81 and a second seal 82, both of which are designed as O-rings. The first seal 81 extends around the fourth portion 19 of the insert 10 so that the portion 19 serves as a collar for the first seal 81. The second seal 82 extends around the tube seal 70. The two seals 81, 82 close the interior of the housing 60 in a fluid-tight manner. This interior is filled with air.

[0045] Figure 6 It is shown how the circuit board 50 is inserted into the insert 10. It is inserted into the insert 10 via the rails 13 from the end of the assembly facing away from the coil 20 until the two locking hooks 11 of the insert 10 engage in two cavities at the edge of the circuit board 50 so that the circuit board cannot move further forwards or backwards. Figure 6 A light source in the form of an LED is arranged on one side of the circuit board that is not visible in the figure, and protrudes from the surface of the circuit board 50. The circuit board 50 is inserted into the insert 10 so that the third positioning element 14 and the light source are located on the same side of the circuit board 50. The LED can emit light through a window (not shown) in the sensor housing 60 in its vicinity and output information about the sensor function.

[0046] Figure 7A spring loaded element in the form of a spring contact 90 is shown arranged on the circuit board 50 at the end of the circuit board 50 facing the coil 20. When the circuit board 50 is inserted into the assembly, the spring loaded element presses against the coil 20 and creates an electrical connection between the circuit board 50 and the coil 20.

[0047] exist Figure 8a to Figure 8g , different embodiments of the spring contacts 90 are shown. The spring contacts are arranged on the metal coating 52 of the circuit board 50 and contact the coil 20. Figure 8a , the spring-loaded element is designed as a spring contact 90, which is bent three times and protrudes from the end of the circuit board 50 in the direction of the coil 20. Figure 8b , the spring contact 90 is bent four times. Figure 8c , it even bent five times. Figure 8d , the spring contact 90 initially protrudes from the circuit board 50 in the opposite direction to the coil 20, then bends so that it extends toward the coil 20 parallel to the circuit board 50, and finally bends twice more so as to contact the coil 20 in the plane of the circuit board 50. Figure 8e In a similar configuration, the coil 20 is contacted above the plane of the circuit board 50. Figure 8f The spring contact 90 bent four times extends from the end of the circuit board 50 toward the coil 20 and is also engaged around the circuit board 50. Figure 8g The spring contact 90 initially extends away from the coil 20, then extends toward the coil 20 parallel to the circuit board 50, and then bends multiple times so as to contact the coil in this way on the one hand, engage around the circuit board 50 on the other hand, and extend away from the coil 20 again parallel to the circuit board 50 under the metal coating 52.

[0048] Fig. 9 An exemplary embodiment is shown in which the spring-loaded element is not arranged on the circuit board 50, but on the circuit board substrate of the coil 20. It is designed as an edge connector 91. When the circuit board 50 is pushed into the assembly, the edge of the circuit board 50 is introduced into the edge connector 91.

[0049] In another exemplary embodiment, a spring-loaded element is provided which is designed as a cable clamp 92. Fig.11 As shown, the cable clamp is arranged on the surface of the circuit board substrate of the coil 20. The top and bottom sides of the circuit board 50 both have a metal coating 52. The circuit board is pushed into the cable clamp 92 so that it contacts the two metal coatings 52.

[0050] Fig.12 Another exemplary embodiment of a sensor is shown, which is consistent with Figure 5The exemplary embodiment of the sensor differs in that the insert 10 is not bonded into the cover 30. Instead, a third seal 83 is provided which extends around the insert 10 and is arranged between the insert 10 and the cover 30. In this exemplary embodiment of the sensor, both the first seal 81 and the third seal 83 are injection-molded onto the insert 10. The insert 10 is fastened in the cover 30 by the third seal 83 and by pressing the first region 16 of the insert 10 with the cover 30.

Claims

1. A sensor assembly, comprising: a cover (30) which is designed essentially in the shape of a hollow cylinder and is closed at a first end, a coil (20) arranged at said first end in said cover (30), and - an insert (10) which is essentially in the shape of a hollow cylinder and is inserted into the cover (30) so that its first end faces the coil (20) and its second end protrudes from the cover (30), wherein the insert (10) has at least one locking hook (11) in its interior, which is designed to be spring-loaded orthogonally to the longitudinal axis of the insert (10).

2. The assembly according to claim 1, characterized in that The insert (10) has at least three partial regions (16-18) in its region arranged in the cover (30), wherein a first partial region (16) borders a second partial region (17), the second partial region (17) borders a third partial region (18), and the third partial region (18) borders the second end of the cover (30), and wherein an outer diameter of the first partial region (16) is greater than an outer diameter of the second partial region (17), and the outer diameter of the second partial region (17) is greater than an outer diameter of the third partial region (18).

3. The assembly according to claim 2, characterized in that The intermediate space between the inner wall of the cover (30) and the second partial region (17) and the third partial region (18) of the insert (10) is filled with an adhesive (41, 42).

4. The assembly according to claim 2 or 3, characterized in that The insert (10) has a fourth partial region (19) located outside the cover, the outer diameter of the fourth partial region being smaller than the outer diameter of the third partial region (18), wherein the first seal (81) is arranged outside the fourth partial region (19).

5. Assembly according to any one of claims 1 to 4, characterized in that The insert (10) has a first positioning element (12) in the form of a protrusion that engages with the coil (20), and has a second positioning element (13) in the form of a track arranged to receive a circuit board (50) pushed through the second end of the insert (10).

6. The assembly according to claim 5, characterized in that The insert (10) has a third positioning element (14) at its second end, and the third positioning element is arranged to align with the light source of the circuit board (50).

7. A sensor comprising the assembly according to any one of claims 1 to 6 and a circuit board (50), wherein the circuit board extends into the assembly through the second end of the insert (10) and is locked by the locking hook (11).

8. The sensor according to claim 7, characterized in that It has at least one spring-loaded element which is in electrical contact with the coil (20) and the circuit board (50).

9. The sensor according to claim 8, characterized in that The spring loaded element is selected from the group consisting of a spring contact (90), an edge connector (91) and a cable clamp (92).

10. The sensor according to any one of claims 7 to 9, characterized in that The assembly and the circuit board (50) are arranged in a housing (60), wherein a tube seal (70) having a plug insert (71) is arranged at one end of the circuit board (50) in the housing (60), and a second seal (82) is arranged between the tube seal (70) and an inner wall of the housing (60).

11. The sensor according to claim 10, characterized in that The circuit board (50) is surrounded by gas.

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