SENSOR WITH HOUSING AND CABLE

Description

[0001] The invention relates to a sensor.

[0002] Such sensors are generally used for object detection and therefore have sensor components that are integrated into at least one housing.

[0003] Optical sensors are an example of such sensors, typically comprising at least one light-emitting transmitter and at least one light-receiving receiver. These sensor components enable object detection within a detection range. An evaluation unit, also a sensor component, processes the received signals from the receiver, generating a corresponding output signal that is sent to an external device.

[0004] A cable is typically used to connect to external units. The cable supplies power to the sensor and also transmits the output signal.

[0005] Known sensors are provided with plug connections, i.e., at one end of the cable there is a plug which is connected to the sensor, with a corresponding connection means, such as a socket, being stored in a housing wall.

[0006] Such connection devices are structurally complex and require a relatively large installation space, resulting in an undesirably large sensor design.

[0007] Generally, it is also possible to attach grommets to cables to store them in an opening of the housing. However, additional mechanical components are required to secure and strain-relieve the cable with the grommet inside the housing, resulting in an undesirably high level of design complexity.

[0008] EP 3 227 641 B1 relates to a wired sensor arrangement in which the conductors of a cable are routed through a housing cover. The cable conductors are soldered, and heat-shrink tubing, previously slipped over the cable ends, is shrunk by applying heat. A strain relief is then overmolded, thus permanently and securely bonding the cover to the cable.

[0009] DE 10 2008 037 208 A1 relates to a cable sheath for a cable with an outer tube and webs arranged on the inside of the outer tube, extending predominantly in an axial direction of the outer tube.

[0010] DE 10 2021 103 232 B3 relates to a connection device for an electrical and / or electronic device comprising a device housing, such as a sensor, a base body with a device-side end, a connection-side end facing away from the device-side end, and a channel extending from the device-side end to the connection-side end, a locking element for securing the base body to a wall section of the device housing, and at least one conductor leading through the base body from the connection-side end to the device-side end. The base body has a first stop surface facing the device-side end of the base body. The locking element has a second stop surface facing the first stop surface.

[0011] DE 100 31 202 A1 relates to an angle measuring device with a housing that has at least one opening in a housing wall forming a circular base of the housing, a cover for closing the at least one opening, and at least one fastening point provided on the housing wall for fixing the cover to the housing wall. Furthermore, a plug connection with a connecting cable is provided.

[0012] The invention is based on the objective of providing a reliable, safe and at the same time structurally simple cable connection with strain relief for a sensor.

[0013] The features of claim 1 are provided to solve this problem. Advantageous embodiments and expedient further developments of the invention are described in the dependent claims.

[0014] The invention relates to a sensor with a housing in which sensor components are integrated. A cable serves as the connection means and is located in an opening in a housing wall. A grommet is provided, which is produced by overmolding a sheath surface of the cable with grommet material. The grommet is pressed into the housing opening and has a locking segment by means of which the grommet is secured against being detached from the housing.

[0015] This also ensures strain relief.

[0016] According to the invention, as a mechanical connection means for connecting a cable to the sensor, the cable is overmolded with grommet material on a segment of its sheathing surface, thereby forming a grommet.

[0017] The geometry of the grommet is adapted to the geometry of a housing opening of the sensor. The grommet is pressed into the housing opening and is then fixed and secured in its intended position within the housing by means of a locking segment that is part of the grommet.

[0018] This fixing can also be achieved additionally by other components that are already present in the housing, such as a housing cover or a circuit board. These have a corresponding counter-contour for fixing the locking element.

[0019] The nozzle can be manufactured efficiently and cost-effectively using injection molding. A suitable injection mold allows the nozzle's geometry to be easily defined and adapted to the housing opening and interior.

[0020] A significant advantage of the invention is to provide the locking segment as a component of the nozzle, i.e., the locking segment is produced in the injection molding process for manufacturing the nozzle without additional effort.

[0021] This offers the significant advantage that the cable is secured in the housing opening solely using the grommet components, potentially in conjunction with the housing geometry and interior; meaning no additional mounting components are required. The cable can also be secured by mounting a housing cover or other device components, such as a circuit board. The necessary securing mechanism against slippage is achieved simply by the mounting of these other components (e.g., housing cover, circuit board, etc.).

[0022] Another significant advantage is that simply by pressing the grommet into the housing opening and inserting it into the corresponding housing geometry, the cable is fixed in position and thus also strain relieved, so that no further steps are required to fix the grommet in the housing opening.

[0023] Advantageously, the nozzle is made of an elastically deformable nozzle material.

[0024] This allows the nozzle to be pressed into the housing opening under elastic deformation and positioned in the intended geometry inside the housing for position fixing.

[0025] Advantageously, the nozzle material consists of an elastically deformable plastic.

[0026] Advantageously, the grommet has a grommet body that extends over the entire circumference of the outer sheath surface of the cable.

[0027] The grommet thus completely encloses the cable and lies within the housing opening over its entire circumference, ensuring a uniform fit of the grommet in the housing opening.

[0028] The geometry of the nozzle is adapted to the geometry of the housing opening, with the nozzle in particular forming a rotationally symmetric body.

[0029] Particularly advantageous when the grommet is pressed into the housing opening is that the locking segment is located on the inside of the housing wall segment that borders the housing opening, or on a housing geometry inside the housing.

[0030] Correspondingly, the nozzle is widened at its front end in the form of a ring segment. When the nozzle is pressed into the housing opening, the ring segment rests with a contact surface against the outer side of the housing wall segment that defines the housing opening.

[0031] When the grommet is pressed into the housing opening, the contact surfaces of the locking segment on the one hand and the ring segment of the nozzle on the other hand lie tightly, preferably form-fitting, against opposite sides of the housing wall, thus ensuring a stable fixation of the grommet in the housing opening.

[0032] According to a structurally advantageous embodiment, the locking segment is formed by a locking lug projecting radially from the socket body.

[0033] The locking lug has an insertion ramp for insertion into the housing opening and a contact surface for contact with the inside of the housing wall.

[0034] The chamfered edge facilitates insertion of the nozzle into the housing opening. Once the locking tab is fully retracted into the housing, the contact surface rests against the housing wall inside the housing.

[0035] The nozzle is fixed in the housing by the locking tab, ensuring the nozzle remains in a stable position.

[0036] According to an alternative design, the locking lug can be fixed to a housing part or a component such as a circuit board inside the housing.

[0037] According to an advantageous embodiment, strain relief means for the cable are provided at the grommet.

[0038] This protects the cable against damage from tensile stress, in addition to the locking segment providing positional security.

[0039] Depending on the tensile load requirement, one or more (metal) sleeves are advantageous as strain relief devices, which are attached to the cable by crimping.

[0040] Each sleeve is crimped onto the cable using crimping pliers. This crimping process protects the cable strands against displacement under tensile forces.

[0041] After the sleeve has been crimped onto the cable using crimping pliers, the sleeve is overmolded with the grommet material that forms the grommet.

[0042] The grommet also encases the cable sleeve, thus protecting the sleeve within the grommet. Furthermore, the grommet enhances strain relief by exerting pressure on the cable and sleeve when pressed into the housing opening.

[0043] According to another advantageous embodiment, a sealing agent is stored at the nozzle.

[0044] This seals the seam between the nozzle and the housing opening, preventing moisture and dirt from entering the interior of the housing.

[0045] According to a structurally advantageous embodiment, the sealant is an O-ring.

[0046] The O-ring is mounted in a groove in the nozzle.

[0047] The sensor can be designed, for example, as a radar sensor or an ultrasonic sensor. An optical sensor is particularly advantageous.

[0048] The optical sensor can be designed, for example, as a distance sensor, reflective light barrier, light switch, scanner, code reader or the like, in which case the optical sensor only has a housing in which the cable connection according to the invention is located.

[0049] The optical sensor can also be designed as a light barrier, light grid, or light curtain. In this case, the optical sensor has two housings, each housing of which can have the cable connection according to the invention.

[0050] The invention will be explained below with reference to the drawings. The drawings show: Figure 1: Exemplary embodiment of the sensor according to the invention in the form of an optical sensor. Figure 2: First embodiment of the cable connection according to the invention for the sensor. Figure 1 Figure 3a: Second embodiment of the cable connection for the sensor according to the invention. Figure 1 Figure 3b: Cross-sectional view of the arrangement according to Figure 3a .

[0051] Figure 1 shows an embodiment of the sensor according to the invention in the form of an optical sensor 1.

[0052] The sensor components of the optical sensor 1 are integrated in a housing 2, in the front wall of which an exit window 3 is provided.

[0053] The optical sensor 1 is designed as a photoelectric sensor and comprises a light beam emitting transmitter 5 and a light beam receiving receiver 6. The transmitter 5 can be a light-emitting diode (LED), and the transmitter 5 may be associated with a transmitting optic (not shown) for shaping the light beams 4. The receiver 6 can be a photodiode, and the receiver 6 may be associated with a receiving optic (not shown) for focusing the light beams 4 onto the receiver 6.

[0054] The optical sensor 1 also includes an evaluation unit 7, which may be a microprocessor or the like. The evaluation unit 7 serves to control the transmitter 5 and receiver 6 and to evaluate received signals from the receiver 6.

[0055] The optical sensor 1 detects objects 8 within a detection area. The light rays 4 emitted by transmitters 5 are guided through the exit window 3 into the detection area. The light rays 4 are reflected by an object 8 within the detection area and then guided back through the exit window 3 to the receiver 6.

[0056] Depending on the received signals of the receiver 6, an object detection signal is generated in the evaluation unit 7, the signal states of which indicate whether an object 8 is in the detection range or not.

[0057] The object detection signal is output from optical sensor 1 to an external unit. A cable 9 serves as the connection point, located in a housing opening 10 in a housing wall 11 of the housing 2 of optical sensor 1. Power to optical sensor 1 is also supplied via cable 9.

[0058] Figure 2 A detailed illustration shows the design of the cable connection according to the invention.

[0059] A sleeve 12 is crimped onto the outer surface of the cable 9. Generally, several sleeves 12 can be crimped on. The sleeve 12 is crimped on using crimping pliers. This stabilizes the strands in the cable 9, thereby relieving strain on the cable 9. The sleeve is advantageously made of a metallic material.

[0060] According to the invention, a grommet 13 is applied to a section of the cable 9 in which the sleeve 12 is also present. The grommet 13 is produced by overmolding the outer surface with a grommet material. The grommet material is advantageously elastically deformable and consists in particular of a plastic. By specifying a suitable injection mold, the geometry of the grommet 13 can be freely selected.

[0061] The grommet 13 extends over the entire circumference of the cable 9's sheath, i.e., the grommet 13 completely encloses the cable 9. The outer contour of the grommet 13 is adapted to the outer contour and size of the housing opening 10, which may have a circular or a non-rotationally symmetrical cross-section. The length and diameter of the grommet 13 are, as Figure 2 shows, adapted to the length and diameter of the housing opening 10.

[0062] Since the cable 9 is only overmolded with the grommet material to form the grommet 13 after the sleeve 12 has been applied, the grommet 13 also surrounds the sleeve 12 and supports the strain relief effect.

[0063] The grommet 13 has a grommet body 14 that abuts the outer surface of the cable 9. At one longitudinal end of the grommet body 14 is a ring segment 15, which forms a widening of the grommet 13, i.e. the outer diameter of the ring segment 15 is larger than the outer diameter of the grommet body 14.

[0064] The ring segment 15 has a flat mounting surface 15a.

[0065] At the opposite longitudinal end of the nozzle body 14 is a locking segment, which in this case is formed by a locking lug 16. The locking lug 16 projects radially beyond the outer surface of the nozzle body 14. The locking lug 16 has a flat contact surface 16a and an insertion ramp 16b.

[0066] The ring segment 15 and the locking lug 16 are components of the nozzle 13 and are formed integrally with the nozzle body 14.

[0067] The nozzle 13 according to the invention forms a press-fit part that is pressed and / or drawn into the housing opening 10. During the pressing-in process, the insertion chamfer 16b is guided against the edge of the housing opening 10, causing the locking lug 16 to deform. Once the nozzle 13 is in its intended position in the housing opening 10 after the pressing-in process, the locking lug 16 lies inside the housing and returns to its original shape (shown in Figure 2 ).

[0068] The grommet 13 with the cable 9 is inserted into the housing opening 10 until the contact surface 15a of the ring segment 15 rests tightly against the outside of the housing wall 11 that defines the housing opening 10. When this is the case, the locking lug 16 protrudes beyond the housing opening 10 and its contact surface 16a rests tightly against the inside of the housing wall 11 that defines the housing opening 10. The distances between the contact surfaces 15a and 16b are dimensioned and adapted to the length of the housing opening 10 such that the grommet 13 is mounted in the housing opening 10 without play and in a positionally stable manner.

[0069] How Figure 2 The figure shows that an O-ring 18 is mounted in a groove 17 of the nozzle 13, forming a sealant. This protects the joint between the edge of the housing opening 10 and the nozzle 13 against the ingress of dirt and moisture.

[0070] The Figures 3a, 3bshow a further embodiment of the cable connection according to the invention for the optical sensor 1.

[0071] As in Figure 2 is in Figure 3a The housing wall 11 is shown with the housing opening 10 in which the cable 9 is stored.

[0072] Figure 3a Figure 2 shows two housing parts 19a and 19b inside the housing 2. The upper housing part 19a is mounted on the lower housing part 19b. A circuit board 20 is attached to the upper housing part 19a with two screws 21 (Figures 3a and 3b).

[0073] The upper housing part 19a lies parallel to and at a distance from the housing wall 11.

[0074] The sleeve 12 is again mounted on the cable 9 and overmolded with the grommet 13. The grommet body 14 is longer than in the embodiment shown. Figure 2 .

[0075] In the present case, two ring segments 15, 15' open onto the socket body 14, which are mirror-symmetrical to a plane perpendicular to the longitudinal axis of the cable 9.

[0076] The distance between the ring segments 15 corresponds to the thickness of the housing wall 11. Since the ring segments 15, 15' and especially the ring segment 15' are elastically deformable, the grommet 13 can be pulled through the housing opening 10, so that after insertion the ring segments 15, 15' lie against the opposing wall segments of the housing wall 11, thereby providing an initial fixation of the cable 9 with the grommet 13.

[0077] As from Figure 3a A locking lug 16 is provided at a distance from the inner ring segment 15, opening onto the nozzle body 14 and protruding into an opening 20a of the circuit board 20.

[0078] The contact surface 15a of the locking lug 16 rests with contact pressure on the interfaces of the circuit board 20 and the upper housing part 19a, so that these form limiting elements which, through the contact of the locking lug 16, lead to the positioning of the cable 9 with the grommet 13.

[0079] In general, only the upper housing part 19a or only the circuit board 20 can form the limiting element, so that the locking lug 16 only rests on this one limiting element. Reference symbol list

[0080] (1) Sensor (2) Housing (3) Exit window (4) Light beam (5) Transmitter (6) Receiver (7) Evaluation unit (8) Object (9) Cable (10) Housing opening (11) Housing wall (12) Sleeve (13) Grommet (14) Grommet body (15, 15') Ring segment (15a, 15b) Contact surface (16) Detent lug (16a) Contact surface (16b) Lead-in chamfer (17) Groove (18) O-ring (19a) Upper housing part (19b) Lower housing part (20) Circuit board (20a) Opening (21) Screw

Claims

1. Sensor with a housing (2) in which sensor components are integrated, wherein a cable (9) is provided as a connection means, which is mounted in a housing opening (10) in a housing wall (11) of the housing (2), wherein a grommet (13) is provided, which is produced by overmoulding a surface of the cable (9) with grommet material, characterised in that the grommet (13) is pressed into the housing opening (10) and the grommet (13) has a locking segment by means of which the grommet (13) is secured against being pulled out of the housing (2).

2. Sensor according to claim 1, characterised in that the sleeve (13) consists of an elastically deformable sleeve material.

3. Sensor according to one of claims 1 or 2, characterised in that the grommet (13) has a grommet body (14) extending over the entire circumference of the outer surface of the cable (9).

4. Sensor according to one of claims 1 to 3, characterised in that, when the grommet (13) is pressed into the housing opening (10), the locking segment rests against the inside of the segment of the housing wall (11) delimiting the housing opening (10) or against a delimiting element in the interior of the housing (2).

5. Sensor according to one of claims 3 and 4, characterised in that the locking segment is formed by at least one locking lug (16) protruding radially from the grommet body (14).

6. Sensor according to claim 5, characterised in that the locking lug (16) has an insertion bevel (16b) for insertion into the housing opening (10) and a contact surface (16a) for contact with the inside of the housing wall (11) or with the limiting element.

7. Sensor according to one of claims 1 to 6, characterised in that the grommet (13) is widened at its front end in the form of a ring segment (15), wherein, when the grommet (13) is pressed into the housing opening (10), the ring segment (15) abuts against a contact surface (15a) against the outside of the segment of the housing wall (11) delimiting the housing opening (10).

8. Sensor according to one of claims 1 to 7, characterised in that strain relief means for the cable (9) are provided on the grommet (13).

9. Sensor according to claim 8, characterised in that at least one sleeve (12) is provided as a strain relief means, which is attached to the cable (9) by crimping.

10. Sensor according to claim 9, characterised in that the sleeve (12) is overmoulded with the grommet material forming the grommet (13).

11. Sensor according to claim 10, characterised in that the grommet (13) and the sleeve (12) form a strain relief means.

12. Sensor according to one of claims 1 to 11, characterised in that a sealing means is mounted on the grommet (13).

13. Sensor according to claim 12, characterised in that the sealing means is an O-ring (18).

14. Sensor according to claim 13, characterised in that the O-ring (18) is mounted in a groove (17) in the grommet (13).

15. Sensor according to one of claims 1 to 14, characterised in that it is an optical sensor (1).