Anti-cheating mileage sensor for taximeter

Abstract

The utility model relates to the technical field of mileage sensors, in particular to an anti-cheating mileage sensor for a taximeter, which comprises a circuit board, a first circuit area of the circuit board is coupled with a detection device, and a second circuit area of the circuit board is electrically connected with the first circuit area through a circuit on a pre-breaking part; a circuit board mounting groove is formed in the end cover, and the pre-breaking part is clamped in the circuit board mounting groove, so that the first circuit area is located in the shell and fixedly connected with the shell, and the second circuit area is located outside the shell and fixes the first circuit area; and when the mileage sensor is screwed, the second line area and the first line area rotate in opposite directions. When the speedometer needs to be disassembled, the action of screwing the shell to try to disassemble the speedometer can cause the first line area or the second line area to be driven to generate relative rotation, and the pre-breaking part is twisted off, so that the speedometer cannot output corresponding data subsequently, and the risk of tampering after the speedometer is disassembled is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of mileage sensors, in particular to a mileage sensor used for preventing cheating in taxi meters. Background Art

[0002] A taxi meter is a device that collects statistics on a taxi's mileage, driving time, driving time period, and other factors, and calculates the fare that passengers should pay based on the corresponding formula. During the pricing process, multiple sensors are often required to work together to calculate the fare. For example, a mileage sensor is used to achieve a more accurate mileage detection effect.

[0003] In the prior art, a Hall sensor or a photoelectric sensor is usually used to connect the gearbox to realize the mileage recording process.

[0004] For example, Chinese patent CN200820020346.8 discloses a magnetic induction speedometer, which is characterized in that: the magnetic resistance ring is axially fixedly connected to the rotating shaft of the gearbox, the Hall sensor and the magnetic resistance ring form an electromagnetic match, and the indicator is electrically connected to the Hall sensor. In this scheme, the magnetic ring is connected to the automobile gearbox. When the car is running, the gearbox shaft drives the magnetic ring to rotate, forming a changing magnetic field induction on the Hall element. When the wheel starts to rotate, the Hall effect sensor starts to generate a series of signals. The number of pulses will increase with the increase of vehicle speed, but the duty cycle of the position remains constant at any speed. At the same time, a series of pulse signals generated by the Hall sensor are reflected on the indicator, which shows the running speed of the vehicle.

[0005] For another example, Chinese patent CN201120261642.9 discloses a non-contact vehicle speed mileage sensor, including a screw, a Hall element is arranged at the end of the screw, the Hall element is mounted on the automobile gearbox and faces the gear of the gearbox in a non-contact manner, and a connector connected to the external automobile instrument and other in-vehicle components is arranged at the other end of the screw. The screw is hollow, and a PCB board is arranged inside it. The PCB board is connected to the Hall element, and the PCB board is directly connected to the Hall element directly to the top of the screw, and fits tightly with the top of the screw. The Hall integrated circuit design is adopted to capture the rotation signal of the gear without contact, and the traditional speed sensor soft shaft and mechanical shaft design are eliminated, which fundamentally solves the failure rate of the vehicle speed mileage sensor. In addition, while reducing the failure rate, the maintenance cost is greatly reduced.

[0006] However, in the actual implementation process, the inventors found that this type of technical solution usually connects a general odometer to the meter to generate a corresponding mileage signal, and its design for anti-cheating is relatively insufficient. A few solutions that take anti-cheating needs into consideration, such as Chinese patent 202121279700.0, also mainly focus on the detection of cheating solutions such as external pulse signals, and do not involve the issue of preventing the internal structure of the odometer from being tampered with. Utility Model Content

[0007] In view of the above problems existing in the prior art, a mileage sensor for preventing cheating of taxi meters is provided.

[0008] The specific technical solutions are as follows:

[0009] A mileage sensor for preventing cheating in a taxi meter, comprising a housing, wherein a mutually coupled detection device and a circuit board are arranged in the housing, wherein the detection device is transmission-connected to an external gearbox transmission shaft so that the circuit board acquires and outputs the rotation speed of the gearbox transmission shaft, and the circuit board comprises a first circuit area, a pre-breaking portion, and a second circuit area;

[0010] The first circuit area is coupled to the detection device, the second circuit area is electrically connected to the first circuit area via the circuit on the pre-breaking portion, and an output port is provided on the second circuit area, and the output port is electrically connected to an external functional circuit;

[0011] An end cover is provided at the first end of the housing, a circuit board mounting groove is provided on the end cover, and the pre-breaking portion is clamped on the circuit board mounting groove, so that the first circuit area is located inside the housing and is connected and fixed to the housing, and the second circuit area is located outside the housing and fixes the first circuit area;

[0012] An upper cover is installed on the outer side of the end cover at the first end of the housing, and the upper cover wraps the end cover and the second circuit area;

[0013] The second circuit area is fixedly connected to the inner surface of the upper cover;

[0014] When the mileage sensor is twisted, the second circuit area rotates in the opposite direction to the first circuit area, so that the pre-breaking portion breaks.

[0015] On the other hand, the detection device comprises:

[0016] A transmission shaft, the lower end of which passes through the second end of the housing and is transmission-connected to an external gearbox output shaft;

[0017] A magnet device is disposed at the upper end of the transmission shaft, a Hall element is mounted on the first circuit board area, and the Hall element is coupled to the magnet device to obtain the rotation speed of the gearbox output shaft.

[0018] On the other hand, the transmission shaft comprises:

[0019] A rotating shaft, the rotating shaft is in the shape of an elongated cube, and a first end of the rotating shaft is transmission-connected to the transmission shaft of the gearbox via a transmission component;

[0020] The second end of the rotating shaft is provided with a first truncated cone and a second truncated cone in sequence, wherein the diameter of the second truncated cone is larger than that of the first truncated cone;

[0021] The first truncated cone is a solid truncated cone, the second truncated cone is a hollow cylindrical shape, and the bottom surface of the second truncated cone contacts the first truncated cone;

[0022] The inner wall of the second truncated table is provided with two magnet mounting seats arranged opposite to each other, and the magnet mounting seats are respectively provided with a first magnet and a second magnet, and the magnetic directions of the first magnet and the second magnet are opposite.

[0023] On the other hand, the upper cover is in the shape of a hollow cylinder, and the outer wall of the upper cover is provided with a hexagonal prism, a cylindrical handle and a fixing area in sequence, and the outer side of the cylindrical handle is provided with anti-slip patterns;

[0024] A pair of clearance cuts are processed on the second circuit area of ​​the circuit board on one side close to the upper cover to form a protrusion, and the protrusion extends into the hollow area of ​​the upper cover;

[0025] After the upper cover is mounted on the housing, sealant is injected into the hollow area to fix the second circuit area and the upper cover.

[0026] On the other hand, the end cover is in a disc shape, and an end cover protrusion is provided on the edge of the end cover, and the outer edge of the end cover protrusion abuts against and is fixed to the inner wall of the shell;

[0027] The end cover is close to the inner side of the shell, and circuit board clamping blocks are distributed along both sides of the circuit board installation groove. The circuit board clamping blocks are respectively against two sides of the first circuit area to limit the rotation of the first circuit area.

[0028] On the other hand, a gearbox fixing sleeve is also provided in the housing, and the gearbox fixing sleeve is fixed on the gearbox housing and allows the detection device to pass through;

[0029] The inner wall of the first end of the housing and the outer wall of the upper end of the gearbox fixing sleeve are respectively provided with matching threads, so that the housing is mounted on the gearbox fixing sleeve through the threads;

[0030] A circuit board baffle is also provided at the upper end of the gearbox fixing sleeve, and the circuit board baffle is clamped on the upper and lower surfaces of the first circuit area of ​​the circuit board;

[0031] When the housing is twisted, the circuit board stopper prevents the first circuit area from rotating.

[0032] On the other hand, a pair of mutually matching meshing teeth are provided on the lower end surface of the first end of the housing and the upper end surface of the gearbox fixing sleeve, so that the housing is restricted to be screwed in in one direction.

[0033] On the other hand, a gearbox screw is disposed on the lower end surface of the gearbox fixing sleeve, and the gearbox fixing sleeve is fixed to the gearbox housing through the gearbox screw.

[0034] The above technical solution has the following advantages or beneficial effects:

[0035] In view of the problem that the anti-disassembly design of the taxi odometer in the prior art is insufficient and it is difficult to prevent the odometer from being disassembled, the above structure is introduced in this solution, and a pre-breaking part is designed for the circuit board area, and it is clamped on the circuit board mounting groove of the end cover, so that the first circuit area and the second circuit area of ​​the circuit board are respectively arranged on the two sides of the end cover and fixed. When the odometer needs to be disassembled, the action of twisting the shell to try to disassemble the odometer will cause the first circuit area or the second circuit area to be driven to produce relative rotation, and the pre-breaking part will be twisted off, so that the odometer cannot output the corresponding data later, avoiding the risk of tampering after the odometer is disassembled. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The embodiments of the present invention will be described more fully with reference to the attached drawings, which are however only used for illustration and description and are not intended to limit the scope of the present invention.

[0037] Figure 1 A cross-sectional view of an embodiment of the utility model;

[0038] Figure 2 This is a schematic diagram of a housing in an embodiment of the utility model;

[0039] Figure 3 This is a schematic diagram of a circuit board in an embodiment of the utility model;

[0040] Figure 4 This is a schematic diagram of a transmission shaft in an embodiment of the utility model;

[0041] Figure 5 This is a schematic diagram of the upper cover in the embodiment of the utility model;

[0042] Figure 6 This is a schematic diagram of the end cover in the embodiment of the utility model;

[0043] Figure 7 This is a schematic diagram of a gearbox fixing sleeve in an embodiment of the utility model;

[0044] Figure 8 This is a schematic diagram of an anti-cheating Hall sensor in an embodiment of the utility model;

[0045] Fig. 9 Schematic diagram of a security chip in an embodiment of the utility model. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0047] In the description of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, if the terms "first", "second", "third" appear, they are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0048] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] Some of the blocks shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0050] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0051] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0052] The utility model includes:

[0053] A mileage sensor for preventing taximeter cheating, such as Figure 1 and Figure 2 As shown, it includes a housing 1, in which a detection device 2 and a circuit board 3 coupled to each other are arranged, and the detection device 2 is connected to an external gearbox transmission shaft so that the circuit board 3 obtains and outputs the rotation speed of the gearbox transmission shaft;

[0054] like Figure 3 As shown, the circuit board 3 includes a first circuit area 31, a pre-breaking portion 32 and a second circuit area 33;

[0055] The first circuit area 31 is coupled to the detection device 2, the second circuit area 33 is electrically connected to the first circuit area 31 via the circuit on the pre-breaking portion 32, and the second circuit area 33 is provided with an output port, which is electrically connected to an external meter;

[0056] The first end of the housing 1 is provided with an end cover 4, and a circuit board mounting groove 41 is formed on the end cover 4. The pre-breaking portion 32 is clamped on the circuit board mounting groove 41, so that the first circuit area 31 is located inside the housing 1 and is connected and fixed to the housing 1, and the second circuit area 33 is located outside the housing 1 and fixes the first circuit area 31.

[0057] The first end of the housing 1 is provided with an upper cover 5 on the outer side of the end cover 4, and the upper cover 5 wraps the end cover 4 and the second circuit area 33;

[0058] The second circuit area 33 is fixedly connected to the inner surface of the upper cover 5;

[0059] When the mileage sensor is twisted, the second line region 33 rotates in the opposite direction to the first line region 31 , so that the pre-breaking portion 32 breaks.

[0060] Specifically, in view of the problem that the anti-disassembly design of the taxi odometer in the prior art is insufficient and it is difficult to avoid the odometer from being disassembled, the above-mentioned structure is introduced in the present solution, and a pre-breaking portion 32 is designed for the circuit board area, and it is clamped on the circuit board mounting groove 41 of the end cover, so that the first circuit area 31 and the second circuit area 33 of the circuit board are respectively arranged on the two sides of the end cover 3 and fixed, wherein the first circuit area 31 can be limited in the shell 1 by means of glue, inner wall clips, baffles, etc., and the second circuit area 33 is wrapped by the upper cover 5 and fixed on the inner side of the upper cover 5 by means of glue, inner wall clips, baffles, etc.

[0061] When the odometer needs to be disassembled, the action of twisting the shell to try to disassemble the odometer will cause the first circuit area 31 or the second circuit area 33 to be driven to produce relative rotation, and the pre-breaking portion 32 will be deformed and twisted off, thereby breaking the circuit on the circuit board 3. The odometer will subsequently be unable to work normally and output corresponding data, avoiding the risk of tampering after the odometer is disassembled.

[0062] In the implementation process, the above-mentioned mileage sensor is mainly fixed on the gearbox so that the detection device 2 can be connected to the output shaft of the gearbox. There is a coupling relationship between the detection device 2 and the circuit board 3. The detection device 2 rotates with the rotation of the output shaft of the gearbox, thereby outputting a corresponding signal to be sensed by the components on the circuit board 3. According to different embodiments, the signal output by the detection device 2 can be an optical signal, a magnetic signal or a signal of other similar principles.

[0063] For example, at least one reflective mark or light-emitting diode is pasted along the circumference of the detection device 2, which can periodically generate light signals as it rotates. A photosensitive device is set at a specific position on the circuit board 3, which can detect the light signal and process it into a corresponding electrical signal and output it.

[0064] For example, in another embodiment, a magnet is provided on the upper edge of the detection device 2, and a Hall element is provided at a specific position on the circuit board 3. With the periodic rotation, the Hall element can detect the magnetic field generated by the magnet, thereby generating and outputting a corresponding electrical signal.

[0065] In one embodiment, Figure 1 As shown, the detection device 2 comprises:

[0066] A transmission shaft 21, the lower end of which passes through the second end of the housing and is transmission-connected to an external gearbox output shaft;

[0067] A magnet device 22 is disposed at the upper end of the transmission shaft 21 , and a Hall element is mounted on the first circuit board area 31 . The Hall element is coupled to the magnet device 22 to obtain the rotation speed of the output shaft of the gearbox.

[0068] Specifically, in order to achieve a better detection effect, in this embodiment, the housing 1 is selected to be set into a hollow cylindrical shape, and the transmission shaft 21 extends from the bottom of the housing 1 and is connected to the transmission output shaft of the gearbox, and rotates with the rotation of the gearbox output shaft. A magnet device 22 is provided at the upper end of the transmission shaft 21, and the magnet device 22 rotates with the rotation of the transmission shaft 21, so that the Hall element on the first circuit board area 31 senses the magnetic field generated by the magnet device 22 and converts it into a periodic electrical signal. By extracting information such as the duty cycle and period of the electrical signal, it is easy to calculate the rotation speed of the gearbox output shaft, and further combine the tire parameters to calculate the mileage. This process belongs to the more common prior art and will not be described here.

[0069] As an optional implementation, a specific gap is configured between the Hall element and the magnet device 22, and the triggering sensitivity of the Hall element is adjusted to avoid being triggered by external interference signals.

[0070] In one embodiment, Figure 4 As shown, the transmission shaft 21 includes:

[0071] A rotating shaft 211, the rotating shaft 211 is in the shape of an elongated cube, and a first end of the rotating shaft 211 is transmission-connected to a transmission shaft of a gearbox via a transmission component;

[0072] The second end of the rotating shaft 211 is provided with a first truncated cone 212 and a second truncated cone 213 in sequence, and the diameter of the second truncated cone 213 is larger than that of the first truncated cone 212;

[0073] The first truncated cone 212 is a solid truncated cone, and the second truncated cone 213 is a hollow cylindrical shape, and the bottom surface of the second truncated cone 213 contacts the first truncated cone 211;

[0074] The inner wall of the second truncated platform 213 is provided with two magnet mounting seats 214 arranged opposite to each other. The magnet mounting seats 214 are respectively provided with a first magnet and a second magnet. The magnetic directions of the first magnet and the second magnet are opposite to each other.

[0075] Specifically, in order to achieve a better detection effect, in this embodiment, the structure of the transmission shaft 21 is adjusted, and a rotating shaft 211 in the shape of a long cube is provided. The rotating shaft 211 is in a quadrangular shape and is inserted into the corresponding transmission component to rotate with the output shaft of the gearbox. The second end of the rotating shaft 211 is provided with a first truncated cone 212 and a second truncated cone 213 with increasing diameters in sequence. The first truncated cone 212 is used as a transition section and the inner bottom surface of the second truncated cone 213. The second truncated cone is in a hollow cylindrical shape, and two magnet mounting seats 214 arranged opposite to each other are provided on the inner wall. The magnetic lines of force of the first magnet and the second magnet are inserted into the magnet mounting seat 214 in parallel with the rotating shaft 211, but the magnetic directions of the first magnet and the second magnet are opposite, for example, the N pole of the first magnet is outside and the S pole of the second magnet is outside. Through this arrangement, the Hall element can detect two opposite magnetic field directions in sequence in one cycle, thereby improving the accuracy of detection.

[0076] In one embodiment, Figure 5 As shown, the upper cover 5 is in a hollow cylindrical shape, and the outer wall of the upper cover 5 is provided with a fixing area 51, a cylindrical handle 52 and a hexagonal prism 53 in sequence, the fixing area 51 is inserted into the first end of the housing 1 and fixed, the outer side of the cylindrical handle 52 is provided with anti-slip lines, and the hexagonal prism 53 is fixedly connected to the external connector;

[0077] The second circuit area 33 of the circuit board 3 is processed with a pair of clearance cutouts 34 on one side close to the upper cover 5 to form a protrusion, and the protrusion extends into the hollow area of ​​the upper cover 5;

[0078] A hollow baffle plate 54 is disposed above the hollow area inside the hexagonal prism 53, and the wiring harness is led out through the holes in the hollow baffle plate 54;

[0079] After the upper cover 5 is mounted on the housing, sealant is injected into the hollow area through the holes on the hollow baffle 54 to fix the second circuit area 33 and the upper cover 5 .

[0080] Specifically, in order to achieve a better fixing effect, in this embodiment, an upper cover 5 structure for wrapping the second circuit area 33 is arranged on the periphery of the first end of the housing 1. The upper cover 5 is in the shape of a hollow cylinder, and a fixing area 51 is arranged at one end. The outer wall of the fixing area 51 is provided with a corresponding buckle, which can be sleeved on the inner wall of the first end of the housing 1 and stuck. At the same time, the protrusion of the second circuit area 33 extends into the hollow area. At this time, the upper cover 5 wraps the end cover 4 and the circuit board 3, and the protrusion of the second circuit area 33 of the circuit board 3 extends into the hollow area. At the same time, its output terminal and wiring harness are led out through the holes in the hollow baffle 54 and connected to the external connector. The connector connector can be sleeved outside the hexagonal prism 53. Between the sleeve joints, the hollow area is sealed by injecting glue into the holes in the hollow baffle 54, which increases the difficulty of disassembly, and the circuit board 3 and the upper cover 5 are glued and fixed, so that when the sensor is twisted, the torque will be transmitted to the circuit board 3 to cause the pre-breaking part 32 to break.

[0081] In one embodiment, Figure 6 As shown, the end cover 4 is disc-shaped, and an end cover protrusion 42 is provided on the edge of the end cover 4. The outer edge of the end cover protrusion 42 abuts against and is fixed to the inner wall of the housing 1;

[0082] The end cover 4 is close to the inner side of the shell, and circuit board clamping blocks 43 are distributed along both sides of the circuit board installation groove 41. The circuit board clamping blocks 43 respectively abut against two sides of the first circuit area 31 to limit the rotation of the first circuit area 31.

[0083] Specifically, in order to achieve better fixation of the first circuit area 31, so as to facilitate breaking the pre-breaking portion 32 during the process of disassembling the sensor, in this embodiment, the structure of the end cover 4 is also adjusted. Among them, the end cover 4 is disc-shaped, and an end cover protrusion 42 is provided on the edge. The outer edge of the end cover protrusion 42 is abutted against and fixed to the inner wall of the shell 1, and can be fixed here by snapping or gluing. At the same time, circuit board clamping blocks 43 are distributed on both sides of the circuit board mounting groove 41. The circuit board clamping block 43 is embodied as a long cubic structure protruding from the plane of the end cover 4, and its relative inner walls respectively clamp the upper and lower surfaces of the circuit board 3 to achieve fixation of the first circuit area 31. When the sensor is disassembled, the end cover 3 is respectively abutted against the two surfaces of the first circuit area 31 through the circuit board clamping block 43 to limit the rotation of the first circuit area 31, so that the torque can be correctly applied to the pre-breaking portion 32.

[0084] In one embodiment, Figure 7 As shown, a gearbox fixing sleeve 6 is also provided in the housing 1, and the gearbox fixing sleeve 6 is fixed on the gearbox housing and allows the detection device 2 to pass through;

[0085] The inner wall of the first end of the housing 1 and the outer wall of the upper end of the gearbox fixing sleeve 6 are respectively provided with matching threads, so that the housing 1 is mounted on the gearbox fixing sleeve 6 through the threads;

[0086] The upper end of the gearbox fixing sleeve 6 is also provided with a circuit board baffle 61, and the circuit board baffle 61 is clamped on the upper and lower surfaces of the first circuit area 31 of the circuit board;

[0087] When the housing 1 is twisted, the circuit board stopper 61 prevents the first circuit area 31 from rotating.

[0088] Specifically, in order to achieve a better anti-disassembly effect, in this embodiment, a gearbox fixing sleeve 6 is also sleeved inside the second end of the housing 1 .

[0089] The gearbox fixing sleeve 6 is in the shape of a hollow cylinder, and a gearbox screw is provided at the bottom thereof, which is roughly hexagonal and matches the mounting hole provided on the gearbox so that the gearbox fixing sleeve 6 can be installed thereon without rotating. The detection device 2 and the corresponding transmission structure are accommodated therein, which can wrap and protect them and prevent them from being disassembled.

[0090] On this basis, the housing 1 is screwed into the gearbox fixing sleeve 6 according to the thread, so that the housing 1 can be fixed on the gearbox housing. Then, according to the opening direction of the circuit board baffle 61 on the gearbox fixing sleeve 6, the circuit board 3 and the end cover 4 clamped on the circuit board 3 are placed. Among them, the circuit board baffle 61 is a protruding part set upward according to the circumferential direction of the gearbox fixing sleeve 6, including two baffles, and an opening for accommodating the first circuit area 31 is set in the middle. Then, the end cover 4 is fixedly connected to the housing 1.

[0091] At this time, the end cap 4, the circuit board 3 and the housing 1 are connected as one, and when the housing 1 is twisted, the first circuit area 31 will abut against the circuit board baffle 61 after turning a certain angle. If further torque is applied at this time, the circuit board 3 will be subjected to the counter torque generated on the circuit board baffle 61, and the pre-broken portion 32 will be broken under the action of the end cap 4, thereby avoiding the possibility of recovery after disassembly and tampering.

[0092] In one embodiment, a pair of mutually matching meshing teeth are provided on the lower end surface of the first end of the housing 1 and the upper end surface of the gearbox fixing sleeve 6 so that the housing 1 is restricted to be screwed in in one direction.

[0093] Specifically, in order to achieve a better anti-disassembly effect, in this embodiment, a pair of mutually matching meshing teeth are also provided on the lower end surface of the first end of the housing 1 and the upper end surface of the gearbox fixing sleeve 6. The meshing teeth are roughly trapezoidal in cross section, with one side being an inclined surface and the other side being a straight surface. When the housing 1 is screwed into the gearbox fixing sleeve 6, the meshing teeth pass forward by the inclined surfaces abutting against each other.

[0094] When trying to disassemble the sensor, the meshing teeth rotate in the opposite direction until the faces abut against each other, thereby preventing the housing 1 from being screwed out in the opposite direction, increasing the difficulty of disassembly.

[0095] In order to achieve better processing effect at the signal level and avoid external interference and cheating, in this embodiment, the following technical means are also used to avoid tampering.

[0096] In one embodiment, Figure 8 As shown, an anti-cheating Hall sensor 3A is also provided on the circuit board 3, and the projection position of the anti-cheating Hall sensor 3A on the end surface of the detection device is different from the projection position of the Hall element 3B on the end surface of the detection device 2;

[0097] A processing circuit 3C is provided on the circuit board, and the processing circuit 3C is connected to the anti-cheating Hall sensor 3A and the Hall element 3B respectively;

[0098] When the anti-cheating Hall sensor 3A is triggered by an external magnetic field, the anti-cheating Hall sensor 3A outputs a cheating detection pulse;

[0099] When the Hall element 3B is triggered by an external magnetic field, the Hall element 3B outputs a mileage detection pulse;

[0100] The processing circuit 3C counts the mileage detection pulses to determine the mileage only when no cheating detection pulses are received.

[0101] Specifically, in order to implement the anti-cheating process, in this embodiment, an anti-cheating Hall sensor 3A is also provided on the circuit board 3, and the projection position of the anti-cheating Hall sensor 3A on the end surface of the detection device is different from the projection position of the Hall element 3B on the end surface of the detection device 2.

[0102] As the detection device 2 rotates, the magnet device 22 rotates on the end face of the detection device 2, and the magnetic field generated by it periodically passes through the anti-cheating Hall sensor 3A and the Hall element 3B, so that the anti-cheating Hall sensor 3A and the Hall element 3B generate corresponding pulse signals in sequence. Usually, due to different installation positions, the pulse signals generated by the anti-cheating Hall sensor 3A and the Hall element 3B will be staggered in timing, and the processing circuit 3C can process the duty cycle and other information of the mileage detection pulse output by the Hall element 3B, thereby obtaining the corresponding mileage counting result.

[0103] However, when an external magnetic field is applied to the sensor to tamper with the mileage, the external magnetic field usually has a large coverage area, which will cause the anti-cheating Hall sensor 3A to continuously generate cheating detection pulses, thereby disabling the mileage calculation program in the processing circuit 2. At this time, the processing circuit 2 no longer calculates the mileage according to the mileage detection pulses, avoiding the possibility of cheating.

[0104] In one embodiment, the sensitivity of the anti-cheating Hall sensor 3A is higher than the sensitivity of the Hall element 3B.

[0105] Specifically, in order to achieve a better anti-cheating effect, in this embodiment, the sensitivity of the anti-cheating Hall sensor 3A and the Hall element 3B is configured, and a better detection effect of the external magnetic field is achieved by setting the sensitivity of the anti-cheating Hall sensor 3A higher than the sensitivity of the Hall element 3B. At the same time, since the projection position of the anti-cheating Hall sensor 3A on the end face of the detection device is different from the projection position of the Hall element 3B on the end face of the detection device 2, its higher sensitivity will not affect the normal pulse count.

[0106] In one embodiment, the magnet device 22 includes a first magnet and a second magnet arranged in opposite directions, and the Hall element 3B is a bipolar Hall switch. At this time, when the transmission shaft 21 rotates, when the S-pole magnet approaches the bipolar Hall switch, the switch works to output a low level and latches, and when the N-pole magnet approaches the bipolar Hall switch, the switch releases to output a high level and latches. When the processor detects this complete process as a pulse. The bipolar Hall sensor has an operating point of 73GS, and a release point of -73GS, which cooperates with the magnet on the transmission shaft to control the working distance between 2-5 mm. The sensitivity of the anti-cheating detection Hall operating point of plus or minus 60GS is higher than that of the bipolar Hall sensor.

[0107] In one embodiment, Fig. 9 As shown, a security chip 3D is provided on the circuit board 3, and the security chip 3D generates a key pair and sends an encrypted certificate file to the meter 7 based on the key pair;

[0108] The meter 7 decrypts the encrypted certificate file according to the public key in the key pair to obtain the certificate file;

[0109] The processing circuit 3C signs the newly generated mileage signal according to the certificate file and sends it to the meter, and the meter 7 verifies the signature according to the certificate file.

[0110] Specifically, in order to achieve a better encryption effect during data transmission, in this embodiment, a security chip 3D is provided on the circuit board 3. Before starting pricing, the security chip 3D generates a key pair, including a public key and a private key. Subsequently, the security chip 3D transmits the public key to the mother card, and the mother card signs the public key with the private key as the first certificate and returns it to the security chip 3D. Based on the first certificate, the security chip 3D generates an encrypted certificate file, and the mother card transmits the public key to the meter 7. Based on the above settings, the mileage signal can be sent to the meter after signature verification, avoiding the problem of tampering and cheating.

[0111] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A mileage sensor for preventing cheating in taxi meters, characterized in that: The invention comprises a housing, wherein a mutually coupled detection device and a circuit board are arranged in the housing, wherein the detection device is drivingly connected to an external gearbox transmission shaft so that the circuit board acquires and outputs the rotation speed of the gearbox transmission shaft, and the circuit board comprises a first circuit area, a pre-breaking portion, and a second circuit area; The first circuit area is coupled to the detection device, the second circuit area is electrically connected to the first circuit area via the circuit on the pre-breaking portion, and an output port is provided on the second circuit area, and the output port is electrically connected to an external functional circuit; An end cover is provided at the first end of the housing, a circuit board mounting groove is provided on the end cover, and the pre-breaking portion is clamped on the circuit board mounting groove, so that the first circuit area is located inside the housing and is connected and fixed to the housing, and the second circuit area is located outside the housing and fixes the first circuit area; An upper cover is installed on the outer side of the end cover at the first end of the housing, and the upper cover wraps the end cover and the second circuit area; The second circuit area is fixedly connected to the inner surface of the upper cover; When the mileage sensor is twisted, the second circuit area rotates in the opposite direction to the first circuit area, so that the pre-breaking portion breaks.

2. The mileage sensor according to claim 1, characterized in that: The detection device comprises: A transmission shaft, the lower end of which passes through the second end of the housing and is transmission-connected to an external gearbox output shaft; A magnet device is disposed at the upper end of the transmission shaft, a Hall element is installed on the first circuit area, and the Hall element is coupled to the magnet device to obtain the rotation speed of the output shaft of the gearbox.

3. The mileage sensor according to claim 2, characterized in that: The transmission shaft comprises: A rotating shaft, the rotating shaft is in the shape of an elongated cube, and a first end of the rotating shaft is transmission-connected to the transmission shaft of the gearbox via a transmission component; The second end of the rotating shaft is provided with a first truncated cone and a second truncated cone in sequence, wherein the diameter of the second truncated cone is larger than that of the first truncated cone; The first truncated cone is a solid truncated cone, the second truncated cone is a hollow cylindrical shape, and the bottom surface of the second truncated cone contacts the first truncated cone; The inner wall of the second truncated table is provided with two magnet mounting seats arranged opposite to each other, and the magnet mounting seats are respectively provided with a first magnet and a second magnet, and the magnetic directions of the first magnet and the second magnet are opposite.

4. The mileage sensor according to claim 1, characterized in that: The upper cover is in a hollow cylindrical shape, and the outer wall of the upper cover is provided with a fixing area, a cylindrical handle and a hexagonal prism in sequence, the outer side of the cylindrical handle is provided with anti-slip lines, and the hexagonal prism is fixedly connected to an external connector; A pair of clearance cuts are processed on the second circuit area of ​​the circuit board on one side close to the upper cover to form a protrusion, and the protrusion extends into the hollow area of ​​the upper cover; A hollow baffle is provided inside the hexagonal pyramid above the hollow area; After the upper cover is mounted on the housing, sealant is injected into the hollow area to fix the second circuit area and the upper cover.

5. The mileage sensor according to claim 1, characterized in that: The end cover is in a disc shape, and an end cover protrusion is provided on the edge of the end cover, and the outer edge of the end cover protrusion abuts against and is fixed to the inner wall of the shell; The end cover is close to the inner side of the shell, and circuit board clamping blocks are distributed along both sides of the circuit board installation groove. The circuit board clamping blocks are respectively against two sides of the first circuit area to limit the rotation of the first circuit area.

6. The mileage sensor according to claim 1, characterized in that: A gearbox fixing sleeve is also provided in the housing, and the gearbox fixing sleeve is fixed on the gearbox housing and allows the detection device to pass through; The inner wall of the first end of the housing and the outer wall of the upper end of the gearbox fixing sleeve are respectively provided with matching threads, so that the housing is mounted on the gearbox fixing sleeve through the threads; A circuit board baffle is also provided at the upper end of the gearbox fixing sleeve, and the circuit board baffle is clamped on the upper and lower surfaces of the first circuit area of ​​the circuit board; When the housing is twisted, the circuit board stopper prevents the first circuit area from rotating.

7. The mileage sensor according to claim 6, characterized in that: A pair of mutually matching meshing teeth are provided on the lower end surface of the first end of the housing and the upper end surface of the gearbox fixing sleeve, so that the housing is restricted to be screwed in in one direction.

8. The mileage sensor according to claim 6, characterized in that: The lower end surface of the gearbox fixing sleeve is provided with a gearbox screw, and the gearbox fixing sleeve is fixed to the gearbox housing through the gearbox screw.

Images