Device for measuring a force acting on a king pin of a semitrailer, semitrailer, multi-part vehicle

Abstract

The invention relates to a device (100) for measuring a force (FB, FD) acting on a king pin (110) of a semitrailer (205), wherein the device (100) comprises the king pin (110) and a sensor device (115), and the sensor device (115) is configured to determine bending of the king pin (110) caused by the force (FB, FD).

Description

[0001] Device for measuring a load on a kingpin of a semi-trailer

[0002] Acting force, semi-trailer, multi-unit vehicle

[0003] The disclosure relates to a device for measuring a force acting on a kingpin of a semi-trailer. The disclosure also relates to a semi-trailer and a multi-unit vehicle comprising a tractor and a semi-trailer.

[0004] The disclosure relates in particular to semi-trailers or trailers with an electrically driven axle and automated vehicles of level 4 or higher according to SAE J3016 “T axonomy and Definitions for Terms Related to Driving Automation Systems for On-Road Motor Vehicles” dated April 30, 2021.

[0005] A kingpin allows a semi-trailer or a trailer and a towing vehicle to be connected to form a multi-unit vehicle using a fifth wheel coupling. Therefore, forces can act on the kingpin during operation that can reflect forces between the towing vehicle and the trailer. Such forces can be caused by the load, i.e., the mass, of the semi-trailer, but also by load changes or driving dynamics. For example, during braking, a force with a component acting against the direction of travel can act on the kingpin, while during acceleration, a force with a component acting in the direction of travel can act on the kingpin.

[0006] In particular for an automated driving function, knowledge of the forces acting on the kingpin may have to be taken into account in order to be able to control, for example, deceleration of the semi-trailer and / or driving of the semi-trailer.

[0007] EP 0 548 487 A2 discloses a device for measuring the deformation of a component. To reduce the complexity of deformation measurement, an arrangement comprising a transmission element and one or two sensors is provided in the component. The sensor is of a type with a measuring surface that emits an electrical signal dependent on a deformation of the measuring surface. The transmission element is supported on one side by a sensor and on the other side by the component or the other sensor. When the component is deformed, the distance between the support points of the transmission element changes. This change in distance generates a deformation of the measuring surface of the sensor, which is evaluated as a measure of the deformation of the component.

[0008] This discloses a method with which the deflection of a supporting bolt of a fifth wheel coupling can be detected using a sensor in the supporting bolt.

[0009] EP 0 607 855 A1 discloses a device for measuring and displaying the loading status of a semi-trailer. In order to improve a device for measuring and displaying the loading status of a semi-trailer to the effect that a measuring device for determining the loading status of the semi-trailer is created that is easy to handle, even independently of the tractor unit, and that provides the most accurate information possible about the forces acting on the tractor unit, while the device is intended to be as easy to handle as possible, it is disclosed that a pressure or force sensor is arranged on the support coupling of the tractor unit and the semi-trailer.

[0010] It is not yet possible to measure the horizontal or radial forces acting on the towing vehicle at the kingpin, which can occur particularly as a result of braking or acceleration between the semi-trailer and the towing vehicle.

[0011] Instead, it is known to fasten the kingpin using sensor screws, for example, and to measure the forces acting on the screws.

[0012] WO 2022 / 074010 A1 discloses a screw with strain gauges, a kingpin, and a jaw coupling. The sensory screw with a screw head, a screw shaft adjoining the screw head along a screw axis, and a thread formed on the screw shaft comprises a measuring device with a strain gauge arranged along or inside the screw shaft and detecting strains of the screw shaft in the direction of the screw axis. The measuring device comprises at least two electrical connections located as contact points on an outer side of the sensory screw and, in particular, arranged such that they come into contact with two correlating electrical contacts of the socket when the sensory screw is inserted into a socket.Furthermore, a kingpin for a fifth wheel coupling is disclosed, comprising a kingpin shaft, at the first end of which a pin head is arranged and at the second end of which a fastening flange is arranged, wherein the fastening flange has at least one screw hole and at least one screw connection, wherein the sensory screw of this screw connection protrudes through the screw hole.

[0013] The invention is based on the object of enriching the state of the art and providing an improved device for measuring a force acting on a kingpin. In particular, the invention solves the problem of reliably measuring a force acting on the kingpin of a fifth wheel coupling.

[0014] According to one aspect of the invention, a device for measuring a force acting on a kingpin of a semi-trailer is provided. The device comprises the kingpin and a sensor device, and the sensor device is configured to determine a deflection of the kingpin caused by the force.

[0015] It was recognized that the force acting on the kingpin can cause the kingpin to deform, as the kingpin is typically made of a material, such as metal, which allows for particularly elastic deformation when the force is applied. The force acting on the kingpin can be determined by the sensor device via the deformation or, in particular, the deflection caused by the force. It was recognized that the deflection typically has a defined relationship to the acting force. Thus, the acting force can be deduced from the deflection of the kingpin. This enables a direct measurement of the deflection of the kingpin and thus a direct determination of the force acting on the kingpin, which enables reliable and precise measurement.An indirect determination of the force acting on the kingpin by means of forces acting on one or more sensory screws or bolts, which, for example, fasten a mounting flange of the kingpin to a scuff plate of the semi-trailer, may therefore be unnecessary.

[0016] Optionally, the kingpin has an opening, and the sensor device is arranged in the opening and / or at one end of the opening. The opening allows for protected mounting of components of the sensor device. When the kingpin deflects, the opening also deforms, allowing the deflection of the kingpin to be determined in the opening and / or by deformation of the opening.

[0017] Optionally, the kingpin has a pin shaft, and the opening is located within the pin shaft. The pin shaft can typically accommodate a significant portion of the deflection, allowing the opening within the pin shaft to also be deflected, enabling effective and reliable determination of the kingpin's deflection.

[0018] Optionally, the kingpin has a pin head, and the opening extends through the pin shaft into the pin head. The pin head can form one end of the kingpin and therefore experience a comparatively large deflection when the kingpin deflects, which can contribute to effective and reliable determination of the kingpin deflection.

[0019] Optionally, the kingpin has a neutral axis, and the opening is located outside the neutral axis. The neutral axis can be referred to as the zero line, as in strength of materials. The neutral axis is the fiber or layer of a cross-section of the kingpin whose length does not change during deflection, or more generally during twisting and / or bending. In the neutral axis, deflection does not cause tensile or compressive stress. Outside the neutral axis, deflection causes a change in length and thus tensile and / or compressive stress. The neutral axis can correspond to a longitudinal axis of the kingpin. Locating the opening outside the neutral axis enables reliable measurement of the deflection. The distance of the opening to the neutral axis can influence the sensitivity of a measurement and / or the sensor device.

[0020] Optionally, the kingpin has a longitudinal axis, and the opening is arranged to extend parallel to the longitudinal axis. In other words, the opening can be arranged such that the opening extends parallel to the longitudinal axis. The longitudinal axis can be a rotational axis of the kingpin, and in particular of the kingpin shaft and the kingpin head. Thus, there is a distance between the opening and the longitudinal axis, which can influence the sensitivity of the deflection measurement.

[0021] Optionally, the opening has a diameter of 3 mm to 6 mm. This allows the opening to be sufficiently dimensioned to accommodate a component of the device, while at the same time being small enough to only marginally affect the mechanical properties of the kingpin. For example, the opening has a diameter of 4 mm.

[0022] Optionally, the device comprises a fluid disposed in the opening, and the sensor device comprises a fluid pressure sensor for measuring a pressure related to the fluid. It has been recognized that the deflection can result in a change in the volume of the opening. Thus, a fluid disposed in the opening can experience a measurable pressure change, which allows the deflection to be determined.

[0023] Optionally, the device has a transmission element arranged in the opening, and the sensor device has a pressure sensor. The transmission element can also be deflected by a deflection of the opening. The deflection of the transmission element can result in a change in the length of the transmission element, which causes a force acting on the pressure sensor and measurable as pressure. Optionally, the pressure sensor has a deformable membrane, and the transmission element is a compression rod supported on the pressure sensor and partially threadless, with a curved head for interacting with the membrane. The transmission element is thus supported by the head on the pressure sensor. The head can be convexly curved to enable movement on a surface of the membrane with a constant pressure acting on the membrane. The curved head forms a spherical end of the compression rod.The curvature of the head allows for a change in the orientation of the head when the transmission element deflects, enabling accurate measurement. The threadless compression rod represents an effective component of the device that can be positioned in the opening.

[0024] Optionally, the transmission link has a preload when the kingpin is undeformed. This allows for measurable deflection in various directions, leading to relaxation and / or compression of the transmission link. Depending on the direction of the deflection, the tensile or compressive stress, which is measured as compression, can be increased or decreased by the deflection.

[0025] Optionally, the sensor device includes a strain gauge located in the opening. This enables cost-effective measurement of the kingpin deflection, since the opening deflects with the kingpin, thus changing the length of the strain gauge. The change in the length of the strain gauge can lead to a correspondingly measurable electrical signal.

[0026] Optionally, the sensor device is configured to detect a deflection of the kingpin caused by a radial force. It was discovered that the device not only makes it possible to measure an axial force acting on the kingpin, which can, for example, provide information about the load of the semi-trailer, but also all forces, including radial forces, can be measured. The radial force can enable quantification of driving dynamics, for example, a difference in acceleration or deceleration between the towing vehicle and the semi-trailer.

[0027] Optionally, the sensor device has an electronic interface for communicating the sensor device with a braking system and / or an electric drive. This allows the braking system and / or the electric drive to be controlled according to the force acting on the kingpin, for example, to perform an automated driving function and / or to coordinate the driving dynamics of the semi-trailer with those of the tractor unit.

[0028] According to one aspect of the disclosure, a semi-trailer is provided. The semi-trailer comprises the device described above. The device may have one or more of the optional features described above to achieve an associated technical effect.

[0029] According to one aspect of the disclosure, a multi-unit vehicle is provided. The multi-unit vehicle comprises a tractor and the semi-trailer described above. The semi-trailer includes a device for measuring the force acting on the kingpin. The device may include one or more of the optional features described above to achieve an associated technical effect.

[0030] Further features of the invention and its technical effects emerge from the figures and the description of the preferred embodiments shown in the figures.

[0031] Fig. 1 is a schematic representation of a multi-unit vehicle according to one aspect of the invention;

[0032] Fig. 2 is a further schematic representation of a multi-unit vehicle according to one aspect of the invention;

[0033] Fig. 3 is a schematic sectional view of a device according to an embodiment according to an aspect of the invention; Fig. 4 is a schematic sectional view of a device according to an embodiment according to an aspect of the invention; and

[0034] Fig. 5 is a schematic sectional view of a device according to an embodiment according to one aspect of the invention.

[0035] Fig. 1 shows a schematic representation of a multi-unit vehicle 200 according to one aspect of the invention. The multi-unit vehicle 200 is a commercial vehicle and a land vehicle.

[0036] The multi-unit vehicle 200 comprises a tractor 201 and a semitrailer 205 or a trailer. The tractor 201 is configured to be coupled to the semitrailer 205 in order to pull the semitrailers 205. For this purpose, the tractor has a fifth wheel coupling 210.

[0037] The multi-unit vehicle 200 and the function of the fifth wheel coupling 210 are further described with reference to Fig. 2.

[0038] Fig. 2 shows a further schematic representation of a multi-unit vehicle 200 according to one aspect of the invention. Fig. 2 is described with reference to Fig. 1. The towing vehicle 201 and the semi-trailer 205 are shown separated from each other to clarify the structure and function of the fifth wheel coupling 210.

[0039] The semi-trailer 205 includes a kingpin 110 (see also Figs. 3 to 5). The kingpin 110 and the fifth wheel coupling 210 are designed to be operatively connected to one another so that the tractor 201 can pull the semi-trailer 205 or, more generally, move it.

[0040] When the semi-trailer 205 and / or the tractor 201 are moving, forces FB, FD can act between the tractor 201 and the semi-trailer 205, for example due to a difference in the accelerations of the tractor 201 and the semi-trailer 205. The forces FB, FD between the tractor 201 and the semi-trailer 205 cause and / or are forces FB, FD on the kingpin 110. For example, during a relative acceleration of the tractor 201, a force FD acting in the direction of the tractor 205 acts on the kingpin 110; during a relative braking of the tractor 201, a force FB acting in the direction of the semi-trailer 205 acts.

[0041] The semi-trailer 105 comprises a device 100 for measuring a force FB, FD acting on a kingpin 110 of a semi-trailer 205 (not shown in Fig. 2, see Figs. 3 to 5). This makes it possible to measure the deformation in the kingpin and thus, in particular, to detect the radial forces or horizontal forces between the tractor 201 and the semi-trailer 205. This can then be used to control the braking forces and / or an electric axle. For this purpose, the semi-trailer 205 has a braking system 106 and an electric drive 107, which can be communicatively connected to the device 100 and / or controlled by signals from the device 100.

[0042] Fig. 3 shows a schematic sectional view of a device 100 according to an embodiment according to one aspect of the invention. The device 100 is a device 100 for measuring a force FB, FD acting on a kingpin 110 of a semi-trailer 205. Such a semi-trailer 205 is described with reference to Figs. 1 and 2. Fig. 3 is described with reference to Figs. 1 and 2.

[0043] The device 100 according to Fig. 3 comprises the kingpin 110 and a sensor device 115.

[0044] The semi-trailer 205 includes a scuff plate 215 and the kingpin 110 includes a mounting flange 121. The semi-trailer 205 has several screw connections 220 with which the kingpin 110 with the mounting flange 121 is mounted on the scuff plate 215 of the semi-trailer 205.

[0045] The rubbing plate 215 rests on the fifth wheel coupling 210 of the tractor 201, and the kingpin 110 engages the fifth wheel coupling 210. The sensor device 115 is configured to detect a deflection of the kingpin 110 caused by the force FB, FD. The deflection of the kingpin 110 is, in particular, an elastic deformation of the kingpin 110. Due to the action of the force FB, FD (see Fig. 2), the kingpin 110 can be deformed such that the kingpin 110 is deflected in sections perpendicular to its longitudinal axis A.

[0046] The kingpin 110 has an opening 112, and the sensor device 115 is partially disposed, or its components are partially disposed, in the opening 112 and at one end 112a of the opening 112. The opening 112 is a blind hole or a blind bore in the kingpin 110. The opening 112 has a diameter d of 3 mm to 6 mm.

[0047] The kingpin 110 has a pin shaft 111, and the opening 112 is arranged within the pin shaft 111. The kingpin 110 has a pin head 113, and the opening 112 extends through the pin shaft 111 into the pin head 113. The opening 112 is cylindrical and thus defines a main extension direction along a cylinder axis of the opening 112. The opening 112 is arranged extending parallel to the longitudinal axis A in the main extension direction.

[0048] The kingpin 110 has a neutral fiber 114, and the opening 112 is located outside the neutral fiber 114. The neutral fiber 114 is only schematically shown outside the longitudinal axis A. The neutral fiber 114 may coincide with the longitudinal axis A.

[0049] The device 100 has a transmission element 117 arranged in the opening 112, and the sensor device 115 has a pressure sensor 115b. The pressure sensor 115b has a deformable membrane 119, and the transmission element 117 is a compression rod 117' supported on the pressure sensor 115 and partially threadless, having a curved head 119a as the spherical end of the compression rod 117' for interacting with the membrane 119. The compression rod 117' is made, for example, of metal or another suitable elastically deformable material. Deflection of the kingpin 110 causes a deflection of the compression rod 117', which can manifest itself as compressive or tensile stress. Due to the compression or tension, the head 119a of the compression rod 117' interacts mechanically with the membrane 119.The interaction of the head 119a of the pressure rod 117' with the diaphragm 119 leads to a deformation of the diaphragm 119 and thus to a pressure that can be measured by the pressure sensor 115b as an electrical signal. The transmission element 117 has a preload when the kingpin 110 is undeformed.

[0050] Due to the possibility of measuring a deflection of the kingpin 110, the sensor device 115 is configured to determine a deflection of the kingpin 110 caused by a radial force FB, FD.

[0051] The sensor device 115 has an electronic interface 116 for communicatively connecting the sensor device 115 to a braking system 106 and / or an electric drive 107. The sensor device 115 outputs, for example, an analog signal that corresponds to the pressure and thus directly to the deflection of the kingpin 110.

[0052] Fig. 4 shows a schematic sectional view of a device 100 according to an embodiment according to one aspect of the invention. Fig. 4 is described with reference to Fig. 3. The differences between the embodiments of Figs. 3 and 4 are described.

[0053] According to Fig. 4, the device 100 comprises a fluid 120 arranged in the opening 112 and a fluid pressure sensor 115a as a pressure sensor 115b. The fluid 120 is, for example, a liquid or a gas under pressure p. The sensor device 115 comprises the fluid pressure sensor 115a for measuring the pressure p relating to the fluid 120. The fluid 120 is encapsulated in the opening 120 by the fluid pressure sensor 115a in a fluid-tight manner and can thus cause a change in a pressure p upon a deflection of the kingpin 110.

[0054] Fig. 5 shows a schematic sectional view of a device 100 according to an embodiment according to one aspect of the invention. Fig. 5 is described with reference to Fig. 3. The differences between the embodiments of Figs. 3 and 5 are described.

[0055] According to Fig. 5, the sensor device 115 has a strain gauge 115c, schematically represented by a rectangle with a dotted line, arranged in the opening 112. The strain gauge 115c is attached, for example, glued, to a circumferential surface of the opening 112. A deflection of the kingpin 110 causes a deflection of the opening 112 and thus a change in the length of the strain gauge 115c, which causes a change in the electrical resistance of the strain gauge 115c that can be measured by the sensor device 115.

[0056] Those skilled in the art will recognize that the embodiments of Figs. 3 to 5 can be combined. For this purpose, the sensor device 115 can have several of the features shown in Figs. 3 to 5, for example, a transmission element 117 and a fluid 120, a transmission element 117 and a strain gauge 120, a fluid 120 and a strain gauge 120, or a transmission element 117, a fluid 120, and a strain gauge 120, each with corresponding sensors. Through these combinations, the device 100 can determine the deflection using multiple sensors, which can be used to verify the plausibility of the forces FB, FD.

[0057] Reference symbol (part of the description)

[0058] 100 device

[0059] 106 Brake system

[0060] 107 Drive

[0061] 110 kingpins

[0062] 111 tenon shaft

[0063] 112 Opening

[0064] 112a End

[0065] 113 tenon head

[0066] 114 neutral fiber

[0067] 115 Sensor device

[0068] 115a Fluid pressure sensor

[0069] 115b pressure sensor

[0070] 115c strain gauges

[0071] 116 electronic interface

[0072] 117 transmission element

[0073] 117' pressure rod

[0074] 118 metal housings

[0075] 119 Membran

[0076] 119a Head

[0077] 120 Fluid

[0078] 121 Mounting flange

[0079] 200 multi-unit vehicle

[0080] 201 tractor

[0081] 205 semi-trailers

[0082] 210 fifth wheel coupling

[0083] 215 rubbing plate

[0084] 220 screw connection

[0085] A Longitudinal axis d Diameter

[0086] FB force, braking force

[0087] FD force, driving force p pressure

Claims

Patent claims 1. Device (100) for measuring a force (FB, FD) acting on a kingpin (110) of a semi-trailer (205), wherein the device (100) comprises the kingpin (110) and a sensor device (115), and the sensor device (115) is configured to determine a deflection of the kingpin (110) caused by the force (FB, FD).

2. Device (100) according to claim 1, wherein the kingpin (110) has an opening (112) and the sensor device (115) is arranged in the opening (112) and / or at one end (112a) of the opening (112).

3. Device (100) according to claim 1 or 2, wherein the kingpin (110) has a pin shaft (111) and the opening (112) is arranged within the pin shaft (111).

4. Device (100) according to claim 3, wherein the kingpin (110) has a pin head (113) and the opening (112) extends through the pin shaft (111) into the pin head (113).

5. Device (100) according to one of claims 2 to 4, wherein the kingpin (110) has a neutral fiber (114), and the opening (112) is arranged outside the neutral fiber (114).

6. Device (100) according to one of claims 2 to 5, wherein the kingpin (110) has a longitudinal axis (A) and the opening (112) is arranged extending parallel to the longitudinal axis (A).

7. Device (100) according to one of claims 2 to 6, wherein the opening (112) has a diameter (d) of 3 mm to 6 mm.

8. Device (100) according to one of claims 2 to 7, wherein the device (100) comprises a fluid (120) arranged in the opening (112) and the Sensor device (115) comprises a fluid pressure sensor (115a) for measuring a pressure (p) relating to the fluid (120).

9. Device (100) according to one of claims 2 to 8, wherein the device (100) comprises a transmission member (117) arranged in the opening (112) and the sensor device (115) comprises a pressure sensor (115b).

10. Device (100) according to claim 9, wherein the pressure sensor (115b) has a deformable membrane (119) and the transmission member (117) is a pressure rod (117') supported on the pressure sensor (115) and partially thread-free, having a curved head (119a) for interacting with the membrane (119).

11. Device (100) according to claim 9 or 10, wherein the transmission member (117) has a prestress in an undeformed state of the kingpin (110).

12. Device (100) according to one of claims 2 to 11, wherein the sensor device (115) has a strain gauge (115c) arranged in the opening (112).

13. Device (100) according to one of the preceding claims, wherein the sensor device (115) is configured to determine a deflection of the kingpin (110) caused by a radial force (FB, FD).

14. Device (100) according to one of the preceding claims, wherein the sensor device (115) has an electronic interface (116) for connecting the sensor device (115) to a braking system (106) and / or an electric drive (107) by means of communication.

15. Semi-trailer (105) comprising a device (100) according to one of the preceding claims.

16. Multi-unit vehicle (200) comprising a tractor (201) and the semi-trailer (205) according to claim 15.

Images