SENSOR DEVICE WITH AN ULTRASOUND SENSOR

Description

[0001] The invention relates to a sensor device comprising a sensor unit having an ultrasonic sensor and a measuring tube, wherein the sensor unit is arranged at one end of the measuring tube. Furthermore, the invention relates to a motor vehicle having such a sensor device.

[0002] A sensor device mentioned above is known, for example, from a piston-cylinder arrangement with a motion detection device. The cylinder of this arrangement corresponds to the measuring tube, and the motion detection device, which consists of a transmitter and a receiver, is arranged within a piston rod guide arranged at a first end of the cylinder. During operation of the motion detection device, sound waves are emitted, and the propagation time of the emitted sound waves is a measure of the distance between a sound source of the motion detection device and a reflection body reflecting the emitted sound waves.

[0003] The known sensor device requires a piston rod guide with a motion detection device that is specifically tailored to and adapted to the corresponding cylinder of the sensor device. This makes the manufacture of such a sensor device not only costly, but also complex to adapt such a sensor device to different vehicle types, for example.

[0004] Installed in a motor vehicle, such a sensor device can be used, for example, to measure a change in the height of a vehicle body. The change in height can be evaluated, for example, as a measure of a weight load, such as the vehicle's load.

[0005] WO 93 / 20412 A1 discloses a device for measuring a distance using an ultrasonic transducer. The device consists of at least a measuring tube, a float, and a reflector. An intermediate tube section can be arranged between the ultrasonic transducer and the measuring tube.

[0006] JP H08 210905 A discloses a load weight measuring device for a truck. Distance sensors, which may be ultrasonic sensors, are intended to measure distances between a truck body and axles mounted on lower parts of the body.

[0007] A liquid level detector comprising a detector body, an acoustoelectric transducer, and an acoustic waveguide is known from US 2004 / 182149 A1. The waveguide may be in the form of a tube and is connected to the detector body by means of a sleeve coupling.

[0008] US 2017 / 254694 A1 discloses an on-board load weight measurement system for vehicles with air suspension and / or mechanical suspension. The load weight measurement system includes resistance sensors or inductive sensors.

[0009] The invention is based on the object of creating a sensor device of the type mentioned above that enables a simple and reliable arrangement of the sensor unit on the measuring tube while simultaneously ensuring high functional reliability of the sensor device. Furthermore, the invention is also aimed at creating a motor vehicle with such a sensor device.

[0010] The first-mentioned object is achieved according to the invention with a sensor device according to claim 1.

[0011] Due to the special sensor adapter present in the sensor device, the invention offers the particular advantage that, for example, a specific type of sensor unit can be used with different measuring tube types simply by selecting a suitable sensor adapter. This results in significant cost advantages, particularly in the large-scale production of sensor devices for different applications, for example. The aforementioned different measuring tube types can differ, for example, in that measuring tubes have a different inner measuring tube diameter and / or a different outer measuring tube diameter depending on the measuring tube type.

[0012] Furthermore, the adapter tube section encompassing the tube end in the invention enables particularly simple and reliable installation of the sensor unit on the measuring tube. Furthermore, the arrangement of the sensor adapter at the tube end, which seals off the end of the tube, ensures that no interfering bodies, such as moisture or contaminant particles, can penetrate into the measuring chamber within the measuring tube from the sensor unit side.

[0013] The ultrasonic sensor is advantageously protected and located within the measuring tube. The measuring tube can easily be filled with air, for example. However, it is also conceivable for the measuring tube to contain another gas or liquid.

[0014] The measuring tube is preferably linear, i.e., straight. The sensor unit, together with the sensor adapter, closes the end of the measuring tube. The sensor adapter is preferably attached to the end of the tube, whereby such attachment can be detachable or non-detachable.

[0015] Due to the advantageous suitability of the sensor device according to the invention for large-scale production, possibly also with a wide range of variants, due to the sensor adapter and, among other things, its special design with the adapter tube section, the sensor device according to the invention is particularly suitable for use in a motor vehicle. The sensor device preferably serves to measure a change in the height of a vehicle body relative to a chassis of the motor vehicle. The sensor device is advantageously suitable for use in an on-board weighing system of a motor vehicle, in particular a commercial vehicle, for example a truck.

[0016] Advantageously, further increased flexibility in the use of the sensor unit according to the invention is achieved because the sensor unit and the sensor adapter are detachably connected to one another. In this way, for example, by selecting a correspondingly adapted sensor adapter, a specific type of sensor unit can be connected to different types of measuring tubes or used to form a sensor device. The sensor adapter can preferably have an anti-twist feature that serves to ensure that the sensor adapter is positioned securely relative to the sensor unit. The anti-twist feature can be formed, for example, as an adapter recess on the sensor adapter. In The adapter recess fits the sensor unit precisely.

[0017] It is generally conceivable, for example, that the sensor adapter of the sensor unit is glued or screwed to the pipe end of the measuring pipe. Furthermore, it is conceivable, for example, that the sensor adapter is plugged onto the pipe end and secured to the pipe end by means of the retaining clip. A particularly simple and at the same time positionally secure, in particular twist-proof, arrangement of the sensor adapter at the pipe end can, however, be achieved if, according to another advantageous development of the invention, the sensor adapter and the pipe end have a locking mechanism. In particular, the adapter pipe section of the sensor adapter and the pipe end can have the locking mechanism. The locking mechanism is a joint locking of the sensor adapter and the pipe end. The locking mechanism could also be referred to as a clip-in mechanism.Preferably, the locking mechanism can be designed to ensure splash protection, thus creating a splash-proof connection between the sensor adapter and the pipe end. If necessary, the locking mechanism can be provided in addition to a retaining clip connection between the sensor adapter and the pipe end.

[0018] The structure of the sensor device is advantageously further simplified because, according to the invention, a retaining clip connecting the sensor adapter to the sensor unit is arranged on the sensor adapter. The sensor unit and sensor adapter are thus advantageously connected to one another by means of a single component, namely the retaining clip, and are preferably detachably connected to one another. The retaining clip can, for example, be designed as a clip. The retaining clip can, in particular, be arranged concentrically to a measuring tube center axis of the measuring tube. In addition, the retaining clip can advantageously have a seal so that, for example, access to the sensor unit with tampering intent leads to the destruction of the seal and is thus also detectable afterwards. In a further embodiment, the retaining clip can be arranged captively on the sensor adapter or on the sensor unit.

[0019] According to an advantageous development of the invention, the sensor adapter has at least one slot, and the retaining clip engages at least partially in the slot. This simultaneously enables simplified manufacture of the sensor device and ensures a reliable fit of the retaining clip on the sensor adapter. The slot of the sensor adapter can preferably be a circumferential slot. In particular, the slot can be arranged perpendicular, namely transversely, to the measuring tube center axis of the measuring tube. The retaining clip can preferably be arranged at least partially in the slot. Preferably, the sensor adapter has two slots, and the retaining clip engages with a respective retaining clip leg in one of the slots.

[0020] One could, for example, imagine that the sensor adapter and the pipe end are glued together or, for example, connected solely by means of a latch. However, the invention provides that the retaining clip secures the sensor adapter to the pipe end. This enables a reliable arrangement of the sensor unit on the measuring tube that is nevertheless easily removable, for example for maintenance purposes. The retaining clip can be present in addition to a latch, for example in addition to the latch described above, between the sensor adapter and the pipe end. The retaining clip can then, for example, secure the latch, for example, protecting the latch from a, particularly unintentional, release of the latch itself.

[0021] According to another advantageous development of the invention, a seal is arranged between the sensor unit and the sensor adapter. This allows for secure closure of the end of the measuring tube, particularly when the sensor unit and the sensor adapter are detachably connected to one another. The seal can preferably be an O-ring, also referred to as an O-ring or O-cord ring. The seal can be secured, for example, by a retaining clip, in particular by a retaining clip as described above.

[0022] It is fundamentally conceivable for the sensor unit to have a fixed cable connection, for example, to a control unit of a motor vehicle. However, for example, for subsequent installation of a sensor device according to the invention in a motor vehicle, it is particularly advantageous if, according to a further development of the invention, the sensor unit has a sensor connection element. The sensor connection element can be designed, for example, as a plug. The sensor connection element can also have sensor electronics, for example for signal conditioning of a measurement signal from the ultrasonic sensor of the sensor unit.

[0023] The second object mentioned above is achieved with a motor vehicle according to claim 6.

[0024] The chassis of the motor vehicle can, for example, be an unsprung chassis. The vehicle body can, in particular, be a sprung vehicle body. To suspend the vehicle body, at least one spring, for example a leaf spring, in particular a leaf spring assembly, and / or an air spring, can be arranged between the chassis and the vehicle body. Depending on the loading or unloading of the vehicle body, the spring arranged between the chassis and the vehicle body is loaded or unloaded, i.e., there is a change in the weight load on the spring. Corresponding to the change in the weight load, i.e., the loading or unloading of the spring, the distance between the chassis and the vehicle body changes. Such a change in the distance, which can also be referred to or viewed as a change in height between the chassis and the vehicle body, can advantageously be detected and measured by means of the sensor device.Such a change in height is a measure of a change in the weight load on the vehicle body. Thus, by measuring the change in height, a statement can be made about the size of the vehicle's load. Loading the vehicle leads to a reduction in the distance and thus to a negative change in height between the vehicle body and the chassis, whereas unloading the vehicle leads to an increase in the distance and thus to a positive change in height between the vehicle body and the chassis. Thus, the sensor device can advantageously be part of a vehicle's own weight detection system, a so-called on-board weighing system.

[0025] It is particularly advantageous that, with the present invention, for example, it is not necessary to mount a sensor for weight measurement directly on or to, for example, a steel spring, in particular a leaf spring, which could lead to damage to the spring. Furthermore, with the present invention, it is also advantageously not necessary to mount a sensor for weight measurement directly on or to a vehicle axle of the motor vehicle, which could lead to falsified measurement results, since it is complex and difficult to distinguish between, for example, an additional weight load of the motor vehicle and driving over uneven road surfaces or curbs.

[0026] According to an advantageous development of the invention, a shock absorber is arranged between the vehicle body and the chassis, wherein the shock absorber is connected to the vehicle body with a first damper end and to the chassis with a second damper end, and wherein the sensor device is arranged on the shock absorber. A particular advantage of such a development is that the sensor device can be easily retrofitted into the motor vehicle, for example, as an accessory. The shock absorber can, in particular, be a cylindrical shock absorber. The measuring tube of the sensor device is preferably arranged parallel to the shock absorber.

[0027] According to another advantageous development of the invention, the first tube end of the measuring tube is attached to the first damper end, and the second tube end of the measuring tube is attached to the second damper end. Preferably, the first tube end of the measuring tube is the tube end at which the sensor adapter is arranged. Preferably, the measuring tube can be subsequently attached to the shock absorber, for example, by screwing or clipping. Furthermore, the measuring tube can be detachably attached to the shock absorber, so that it can be easily removed from the shock absorber, for example.

[0028] The invention also includes further developments of the motor vehicle according to the invention which have features as have already been described in connection with further developments of the sensor device according to the invention and vice versa.

[0029] The invention also includes combinations of the features of the described embodiments.

[0030] Embodiments of the invention are illustrated schematically and sketchily in the drawings and are described in more detail below. They show, in schematic and sketchy representations: Fig. 1 a section of a sensor device in sectional view, Fig. 2 the sensor device according to Fig. 1 in a perspective view, Fig. 3 a sensor unit of the sensor device according to Fig. 1 in a perspective view, Fig. 4 a sensor adapter of the sensor device according to Fig. 1 in a perspective view, Fig. 5 a retaining clip of the sensor device according to Fig. 1 in a perspective view, Fig. 6 a section of a shock absorber and a sensor device in a perspective view and Fig. 7 a motor vehicle with several sensor devices.

[0031] Corresponding elements are provided with the same reference numerals in all figures.

[0032] Figure 1shows a schematic and sketchy representation of a section of a sensor device 1 with a sensor unit 4 having an ultrasonic sensor 2. The sensor device 1 also has a linear measuring tube 6, of which only a section with a first tube end 8 is shown here. The sensor unit 4 is arranged at the tube end 8.

[0033] The sensor unit 4 has a sensor adapter 10. The sensor adapter 10 has an adapter pipe section 12 that surrounds the pipe end 8 and is arranged at the pipe end 8 so as to close the pipe end 8.

[0034] The sensor unit can form a single component with the sensor adapter, i.e. in particular can be formed in one piece. In In the embodiment shown here, however, the sensor unit 4 and the sensor adapter 10 form two components. Furthermore, the sensor unit 4 and the sensor adapter 10 are detachably connected to one another.

[0035] To seal the connection between the sensor unit 4 and the sensor adapter 10 as well as the pipe end 8 of the measuring tube 6, a seal 14 is arranged between the sensor unit 4 and the sensor adapter 10. In In the embodiment shown here, the seal 14 is designed as an O-ring 16.

[0036] A retaining clip 18 is arranged on the sensor adapter 10, connecting the sensor adapter 10 to the sensor unit 4. The retaining clip 18 also secures the seal 14 between the sensor adapter 10 and the sensor unit 4, thus ensuring a reliable seal. The retaining clip 18 also secures the sensor adapter 10 with the sensor unit 4 to the tube end 8 of the measuring tube 6. The retaining clip 18 is designed as a U-shaped clip (see FIG. Figure 5 ). It is made in one piece, for example from a plastic material or from a metal material, for example a wire.

[0037] In particular from Figure 4It becomes clear that the sensor adapter 10 has a receptacle 20 for the retaining clip 18. In the embodiment shown here, the receptacle 20 is designed as a slot 22. The retaining clip 18 engages at least partially in the slot 22 (cf. Figure 2 ). In this embodiment, the receptacle 20 also has a second slot 23. The retaining clip 18 engages with a retaining clip leg 35, 37 (cf. Figure 5 ) into one of the slots 22, 23 of the holder 20.

[0038] In addition, the sensor adapter 10 and the tube end 8 of the measuring tube 6 share a common locking mechanism 24. The locking mechanism 24 includes a nub 26 on the adapter tube section 12 of the sensor adapter 10 and a recess 28 in the tube end 8 of the measuring tube 6. The recess 28 corresponds to the nub 26 such that, when the sensor unit 4 and the measuring tube 6 are assembled, the nub 26 engages the measuring tube 6. The locking mechanism 24 ensures, among other things, a rotation-proof arrangement of the sensor adapter 10 and the measuring tube 6.

[0039] In addition, the sensor adapter 10 has an anti-twist device 31, which serves to ensure that the sensor adapter 10 is positioned securely against rotation relative to the sensor unit 4. The anti-twist device 31 is designed here as an adapter recess 33 on the sensor adapter 10. The sensor unit 4 fits precisely into the adapter recess 33 (see Figure 2 ).

[0040] For example, Figure 3As can be seen, the sensor unit 4 has a receptacle 30 of the sensor unit 4 for the retaining clip 18, which corresponds to the receptacle 20 of the sensor adapter 10 for the retaining clip 18. The receptacle 30 of the sensor unit 4 is designed here as a groove 32. Figure 5 shows the retaining clip 8 with clip areas 34, 36 of the retaining clip legs 35, 37 engaging in the receptacle 20 of the sensor adapter 10 and in the receptacle 30 of the sensor unit 4.

[0041] The sensor unit 4 also has a sensor connection element 38. The sensor connection element 38 has a connector 40 for connecting the sensor device 1, for example, to a control unit of a motor vehicle.

[0042] Figure 7shows a sketch of a motor vehicle 42 with several shock absorbers 44 arranged between a chassis of the motor vehicle 42 and a vehicle body (not shown here) of the motor vehicle 42. The shock absorbers 44 are each connected to the vehicle body by a first damper end 46 and to the chassis by a second damper end 48. A sensor device 1 is arranged on each of the shock absorbers 44 (see Figure 6 ).

[0043] In each case, a first tube end 8 of a measuring tube 16 is fastened to the respective first damper end 46, and a second tube end 50 of the respective measuring tube 16 is fastened to the respective second damper end 48. The sensor devices 1 are connected to a control unit 52 of the motor vehicle 42. Information about a loading state, for example a load weight, of the motor vehicle 42, calculated by the control unit 52 from measured values ​​of the sensor devices 1, can be displayed on a display device 54. The display device 54 can, for example, be a component of the motor vehicle 42. However, it is also conceivable for the display device 54 to be a device external to the vehicle, for example a mobile communications unit such as a smartphone or a computer, for example in a freight forwarding center.

[0044] The motor vehicle 42, which may in particular be a commercial vehicle, for example a truck, has in this exemplary embodiment a front axle 56 and a first rear axle 58 as well as a second rear axle 60. The front axle 56 and the two rear axles 58, 60 are components of the chassis of the motor vehicle 42. The vehicle body of the motor vehicle 42 is sprung relative to the front axle 56 by means of a leaf spring 62. Relative to the rear axles 58, 60, the vehicle body is sprung by means of an air spring 64, 66. The leaf spring 62 here has two leaf spring assemblies, and the air springs 64, 66 each have two air springs. In the embodiment shown here, the sensor devices 1 are arranged parallel to the suspensions (leaf springs 62, air springs 64, 66) between the axles (front axle 56, rear axles 58, 60) and the vehicle body.The sensor devices 1 are each assigned to the individual springs (leaf spring assemblies, air springs).

[0045] The motor vehicle 42 has an on-board weighing system, i.e., a weight detection system built into the vehicle. The sensor devices 1, the control unit 52, and the display device 54 are at least partially part of this on-board weighing system, at least partially because, in particular, the control unit 52 and the display device 54 can perform additional functions for the motor vehicle 42 and possibly beyond, in addition to functions for the on-board weighing system.

[0046] Overall, the exemplary embodiments show how the invention can provide a sensor device with a sensor unit having an ultrasonic sensor and a measuring tube, as well as a motor vehicle with such a sensor device, in particular for measuring a change in height of a vehicle body relative to a chassis, in particular in an on-board weighing system.

Claims

1. Sensor device (1) comprising a sensor unit (4), which has an ultrasonic sensor (2), and comprising a measuring tube (6), wherein the sensor unit (4) is arranged at a tube end (8) of the measuring tube (6), wherein the sensor unit (4) has a sensor adapter (10), wherein the sensor unit (4) and the sensor adapter (10) form two components and the sensor unit (4) and the sensor adapter (10) are releasably connected to each other, and wherein the sensor adapter (10) has an adapter tube portion (12) surrounding the tube end (8) and is arranged at the tube end (8) so as to close the tube end (8), characterized in that a retaining clip (18) connecting the sensor adapter (10) to the sensor unit (4) is arranged on the sensor adapter (10) and in that the retaining clip (18) secures the sensor adapter (10) at the tube end (8).

2. Sensor device according to Claim 1, characterized in that the sensor adapter (10) and the tube end (8) have a detent connection (24).

3. Sensor device according to either of the preceding claims, characterized in that the sensor adapter (10) has at least one slot (22) and in that the retaining clip (18) engages at least partially in the slot (22).

4. Sensor device according to any of the preceding claims, characterized in that a seal (14) is arranged between the sensor unit (4) and the sensor adapter (10).

5. Sensor device according to any of the preceding claims, characterized in that the sensor unit (4) has a sensor connection element (38).

6. Motor vehicle (42) comprising a sensor device (1) according to any of the preceding claims, comprising a chassis and comprising a vehicle body, wherein a first tube end (8) of a measuring tube (6) of the sensor device (1) is connected to the vehicle body and a second tube end (50) of the measuring tube (6) is connected to the chassis.

7. Motor vehicle according to Claim 6, characterized in that a shock absorber (44) is arranged between the vehicle body and the chassis, wherein the shock absorber (44) is connected by way of a first absorber end (46) to the vehicle body and by way of a second absorber end (48) to the chassis, and wherein the sensor device (1) is arranged on the shock absorber (44).

8. Motor vehicle according to Claim 7, characterized in that the first tube end (8) of the measuring tube (6) is attached to the first absorber end (46) and the second tube end (50) of the measuring tube (6) is attached to the second absorber end (48).