CN111186390A - Purely mechanical anti-dismounting device of vehicle-mounted unit and vehicle-mounted unit - Google Patents

Abstract

The invention provides a purely mechanical anti-dismounting device of a vehicle-mounted unit and the vehicle-mounted unit, wherein the device comprises: back shell, preceding shell, accommodation chamber. The detection point 404 is disposed on the first sidewall and/or the second sidewall of the switch. The side wall of the first connecting rod of the anti-dismantling rod is provided with an accommodating part; the reed is provided with a convex part on the surface far away from the anti-dismantling rod; the second connecting rod sleeve is arranged in the spring. The switch deflector rod comprises a ring-shaped piece, a first deflector rod and a second deflector rod, the first deflector rod and the second deflector rod are respectively arranged on the outer wall of the ring-shaped piece, the ring-shaped piece is sleeved on the first connecting rod, the first deflector rod is positioned between the first side wall and the second side wall, and the distance between the first concave part and the rear shell is smaller than the distance between the second concave part and the rear shell; when the convex part is clamped in the first concave part, the first deflector rod exceeds the detection range of the detection point 404; the moving part of the electric moving assembly receives a control command to move in the direction vertical to the front shell, and the end part of the moving part is opposite to the second shift lever; the circuit board is electrically connected with the switch and the electric motion assembly.

Description

Purely mechanical anti-dismounting device of vehicle-mounted unit and vehicle-mounted unit

Technical Field

The invention relates to the technical field of electronic equipment structures, in particular to a purely mechanical anti-dismounting device of a vehicle-mounted unit and the vehicle-mounted unit.

Background

With the popularization of electronic systems ETC for electronic toll collection, on-board units installed on vehicle sides are widely used. In order to avoid the problem caused by the fact that the vehicle-mounted unit is detached from the window and then is mounted on another vehicle, a detachment prevention device (such as a detachment prevention push switch) is required to be arranged on the vehicle-mounted unit to detect whether the vehicle-mounted unit is detached. Specifically, the existing on-board unit is usually powered by a battery, a chip of the on-board unit is connected with the battery and a tamper switch, respectively, and when the on-board unit is correctly installed, the tamper switch is pressed down, and when the on-board unit is detached, the tamper switch bounces, so that the chip can record the state of the switch, and the detachment of the on-board unit is detected through the bouncing of the switch. However, since the battery may be damaged or there is no power, in case of power failure of the chip, the chip of the on-board unit cannot detect whether the on-board unit is detached, and if the on-board unit is detached, swiped and remounted to the vehicle entrance window at the time of power failure, since the removal prevention switch is pressed again after remounted, at which time the battery is immediately replaced or charged, the on-board unit still cannot detect whether it has been detached during the power failure. Therefore, a new technology is needed to solve the problem that the vehicle-mounted unit cannot detect whether the unit is detached during power failure.

Disclosure of Invention

The present invention is intended to solve the above-mentioned technical problems.

The invention mainly aims to provide a purely mechanical anti-dismounting device of an on-board unit.

It is another object of the present invention to provide an on-board unit.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

one aspect of the present invention provides a purely mechanical tamper-evident device for an on-board unit, the device comprising: the rear shell 1, the rear shell 1 is provided with a through hole 101; the front shell 2, the front shell 2 and the rear shell 1 are assembled to form an accommodating cavity 3; a switch 4, the switch 4 is arranged in the accommodating cavity 3, the switch 4 comprises a bottom 401 and a first side wall 402 and a second side wall 403 which are respectively arranged vertically to the bottom 401, the first side wall 402 and the second side wall 403 are arranged oppositely, a detection point 404 is arranged on the surface of the first side wall 402 opposite to the second side wall 403, and/or a detection point 404 is arranged on the surface of the second side wall 403 opposite to the first side wall 402; the anti-disassembly rod 5 is arranged in the accommodating cavity 3 and penetrates through the through hole 101, the anti-disassembly rod 5 comprises a pressing part 501, a first connecting rod 502, a blocking part 503 and a second connecting rod 504 which are sequentially connected, the pressing part 501 is positioned on the outer side of the rear shell 1, and the accommodating part 5021 is arranged on the side wall of the first connecting rod 502; a reed 6, the reed 6 being disposed in the housing 5021, the reed 6 being provided with a protrusion 601 on a surface remote from the tamper bar; a spring 7, one end of the spring 7 is fixed on the inner surface of the front housing 2, the second link 504 is sleeved in the spring 7, and the other end of the spring 7 presses on the blocking part 503; switch deflector rod 8, switch deflector rod 8 is set in accommodating cavity 3, switch deflector rod 8 includes annular piece 801, first deflector rod 802 and second deflector rod 803 are set up on the outer wall of annular piece 802 separately, the annular piece 801 is fitted on first tie rod 502, first deflector rod 802 locates between first sidewall 402 and second sidewall 403, and set up first concave section 8011 and second concave section 8012 on the inner wall of the annular piece 801, first concave section 8011 and second concave section 8012 set up in order in the direction perpendicular to front shell 2, and the distance of first concave section 8011 and rear shell 1 is smaller than the distance of second concave section 8012 and rear shell 1; when the protruding portion 601 is engaged with the first recess 8011, the first lever 802 moves out of the detection range of the detection point 404. The electric movement assembly 9, the electric movement assembly 9 is set in the containing cavity 3, the electric movement assembly 9 includes a fixed part 901 and a moving part 902, the fixed part 901 is fixed on the inner surface of the front shell 2, the moving part 902 receives a control command to move in the direction perpendicular to the front shell 2, the end of the moving part 902 is set opposite to the second driving lever 803; and a circuit board 10, wherein the circuit board 10 is arranged in the accommodating cavity 3 and is electrically connected with the switch 4 and the electric motion assembly 9.

Optionally, the switch 4 comprises: a mechanical push switch, a mechanical toggle switch, a photoelectric switch, or an electromagnetic switch.

Optionally, the area of the projection of first shifter lever 802 on first sidewall 402 is larger than the area of the detection point.

In another aspect of the invention, an on-board unit is provided that includes a purely mechanical tamper-evident feature of the on-board unit described above.

According to the technical scheme provided by the invention, the invention provides a purely mechanical anti-dismounting device of an on-board unit and the on-board unit. In the present invention, the spring of the anti-removal lever is provided with a projection, and the switch lever is provided with a first recess and a second recess, and the projection engages with the second recess when the on-vehicle unit is in normal use, and the anti-removal lever is ejected after the on-vehicle unit is removed, and the projection engages with the first recess, and even if the on-vehicle unit is remounted to the window, the anti-removal lever is pressed down, but the projection still engages with the first recess. The switch can detect the working signal only when the anti-disassembly rod is pressed down and the convex part is clamped with the second concave part and the first deflector rod is in the detection range of the switch detection point. Therefore, after the in-vehicle unit is detached, the switch cannot detect the operation signal because the convex portion cannot return to the position of engagement with the second concave portion again. Therefore, whether the vehicle-mounted unit is detached or not is recorded under the condition of no power supply through the pure mechanical detachment prevention structure.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is an exploded view of the structure of an on-board unit provided in the embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a vehicle-mounted unit according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of another on-board unit according to an embodiment of the present invention;

fig. 4 is a schematic cross-sectional structure diagram of another on-board unit according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

This embodiment provides an on-board unit, and this on-board unit has included the pure mechanical anti-disassembly device of an on-board unit, and this pure mechanical anti-disassembly specifically includes: backshell 1, preceding shell 2, hold chamber 3, switch 4, prevent tearing open pole 5, reed 6, spring 7, switch driving lever 8, electric motion subassembly 9 and circuit board 10, wherein:

the rear shell 1, the rear shell 1 is provided with a through hole 101. The front shell 2, the front shell 2 and the rear shell 1 are assembled to form a containing cavity 3. In this embodiment, a first engaging member may be disposed on the edge of the rear case 1, and a second engaging member corresponding to the first engaging member may be disposed on the edge of the front case 2, so that the rear case 1 and the front case 2 may be assembled by engaging the first engaging member with the second engaging member. Of course, the rear housing 1 and the front housing 2 may also adopt other equipment methods, such as adhesive connection, and the like, and this embodiment is not particularly limited. The accommodating cavity 3 formed after the rear shell 1 and the front shell 2 are assembled can be in a cuboid shape, and accommodating spaces in different shapes can be formed according to the type of the vehicle-mounted unit.

The switch 4, the switch 4 is disposed in the accommodating cavity 3, the switch 4 includes a bottom 401 and a first sidewall 402 and a second sidewall 403 respectively disposed perpendicular to the bottom 401, the first sidewall 402 and the second sidewall 403 are disposed opposite to each other, a detection point 404 is disposed on a surface of the first sidewall 402 opposite to the second sidewall 403, and/or a detection point 404 is disposed on a surface of the second sidewall 403 opposite to the first sidewall 402. In this embodiment, the switch 4 includes: a mechanical push switch, a mechanical toggle switch, a photoelectric switch, or an electromagnetic switch. As an alternative embodiment, the switch 4 is an optoelectronic switch, the first sidewall 402 and the second sidewall 403 are both provided with the detection point 404, the detection point 404 on the first sidewall 402 may be one of an optical signal transmitter and an optical signal receiver, and the detection point 404 on the second sidewall 403 may be the other of the optical signal transmitter and the optical signal receiver. Thus, when the position of the switch lever 8 is located between the detection point 404 on the first side wall 402 and the detection point 404 on the second side wall 403, the switch lever 8 can block the light signal receiver from receiving the light signal, thereby triggering the on/off of the switch 4. As another alternative, the switch 4 is a mechanical push switch, and the opposite positions of the first sidewall 402 and the second sidewall 403 may be respectively provided with the detection point 404, or only one of the first sidewall 402 and the second sidewall 403 may be provided with the detection point 404, and the detection point 404 may be a push piece of the mechanical push switch. Thus, when the position of the switch lever 8 is located between the detection points 404 on the first sidewall 402 and/or the second sidewall 403, the switch lever 8 can press the pressing piece, thereby triggering on/off of the switch 4. In this embodiment, the switch 4 may also be a mechanical toggle switch, the detection point 404 may be a toggle member of the mechanical toggle switch, and the switch toggle lever 8 toggles the toggle member to turn on/off the switch 4; alternatively, the switch 4 may also be an electromagnetic switch, the detection point 404 may be an electromagnetic sensor of the electromagnetic switch, and the switch lever 8 turns on/off the switch 4 by shielding the electromagnetic sensor.

Prevent tearing open pole 5, prevent tearing open pole 5 and set up in holding chamber 3 to pass through-hole 101, prevent tearing open pole 5 and including the portion 501, first link 502, the stop part 503 and the second link 504 of touching that connect gradually, touch the outside that the portion 501 is located the backshell 1, set up holding portion 5021 on the lateral wall of first link 502. Thereby, the tamper bar 5 can pass through the through hole 101 and be displaced in the vertical direction. As an alternative embodiment, the edge of the through hole 101 may be a step structure, and the shape of the step structure near the outside of the rear case 1 matches the shape of the pressing portion 501, so that the pressing portion 501 is kept outside the rear case 1, that is, the pressing portion 501 is not sunk into the accommodating cavity 3 when the anti-detachment rod 5 is pressed downward, and the upper surface of the pressing portion 501 is flush with the outer surface of the rear case 1 when the anti-detachment rod 5 is pressed downward.

A spring 6, the spring 6 being arranged in the accommodation portion 5021, the spring 6 being provided with a protrusion 601 on a surface remote from the tamper bar. In this embodiment, the spring 6 can be fixed inside the accommodating portion 5021 by means of adhesion or the like. As an alternative embodiment, the spring plate 6 can be provided as an integral structure with the tamper bar 5.

And a spring 7, one end of the spring 7 is fixed on the inner surface of the front case 2, the second link 504 is sleeved in the spring 7, and the other end of the spring 7 presses on the blocking part 503. When the vehicle-mounted unit is fixed on a vehicle window, namely the rear shell 1 of the vehicle-mounted unit is stuck and fixed with the vehicle window, the vehicle window enables the anti-dismantling rod 5 to move downwards along the vertical direction by pressing the touch and press part 501, and the anti-dismantling rod 5 downwards extrudes the spring 7 through the blocking part 503 thereof to enable the spring 7 to be in a compressed state; after the in-vehicle unit is detached from the window, the window no longer presses the pressing portion 501, and the spring 7 extends under the elastic force and presses the stopper 503 upward, thereby moving the detachment prevention lever 5 upward in the vertical direction.

Switch deflector rod 8, switch deflector rod 8 is set in accommodating cavity 3, switch deflector rod 8 includes annular piece 801, first deflector rod 802 and second deflector rod 803 are set up on the outer wall of annular piece 802 separately, the annular piece 801 is fitted on first tie rod 502, first deflector rod 802 locates between first sidewall 402 and second sidewall 403, and set up first concave section 8011 and second concave section 8012 on the inner wall of the annular piece 801, first concave section 8011 and second concave section 8012 set up in order in the direction perpendicular to front shell 2, and the distance of first concave section 8011 and rear shell 1 is smaller than the distance of second concave section 8012 and rear shell 1; when the protruding portion 601 is engaged with the first recess 8011, the first lever 802 moves out of the detection range of the detection point 404. In this embodiment, when protrusion 601 is engaged with first recess 8011, first lever 802 is located above detection point 404, and when switch 4 is an inductive switch such as a photoelectric switch, first lever 802 does not shield the inductor of switch 4, and when switch 4 is a mechanical switch such as a push switch, first lever 802 does not push the push piece of switch 4. First recess 8011 has a size and shape matching those of projection 601, and second recess 8012 has a size and shape matching those of projection 601, so that projection 601 can be caught in first recess 8011 when first recess 8011 is moved to a position corresponding to projection 601, and the relative position of switch lever 8 and tamper proof lever 5 can be fixed without application of other external force. When second recess 8012 moves to a position corresponding to projection 601, projection 601 can be caught in second recess 8012, and the relative position of switch lever 8 and tamper proof lever 5 can be fixed without any other external force. As an alternative embodiment, the protruding portion 601 may have a convex semicircular shape or an arc shape, and the first concave portion 8011 and the second concave portion 8012 may have a concave semicircular shape or an arc shape, so that, when the protruding portion 601 is caught in the first concave portion 8011 or the second concave portion 8012 and under other external forces, that is, when the second lever 803 of the switch lever 8 is pushed vertically upward or vertically downward, the protruding portion 601 can slide out of the first concave portion 8011 or the second concave portion 8012, thereby sliding the ring 801 on the anti-detach rod 5. In this embodiment, the ring 801 slides up and down in the vertical direction on the tamper bar 5, and the first lever 802 can be moved up and down in the vertical direction between the first sidewall 402 and the second sidewall 403. As an alternative embodiment, the area of the projection of first deflector rod 802 on first sidewall 402 is larger than the area of detection point 404. Therefore, when the first lever 802 moves to a position opposite to the detecting point 404, the first lever 802 can completely cover the detecting point 404. When the switch 4 is an inductive switch such as a photoelectric switch or an electromagnetic switch, the first toggle lever 802 can completely block the inductive signal of the detection point 404. When the switch 4 is a mechanical switch such as a mechanical push switch, the first lever 802 can sufficiently push the push piece of the push switch.

The electric movement assembly 9, the electric movement assembly 9 is arranged in the accommodating cavity 3, the electric movement assembly 9 comprises a fixed part 901 and a moving part 902, the fixed part 901 is fixed on the inner surface of the front shell 2, the moving part 902 receives a control command to move in the direction vertical to the front shell 2, and the end part of the moving part 902 is arranged opposite to the second driving lever 803. The end of the electro-kinetic assembly 9 can thus controllably push the second rod 803 upwards, moving the switch rod 8 upwards.

And a circuit board 10, wherein the circuit board 10 is arranged in the accommodating cavity 3 and is electrically connected with the switch 4 and the electric motion assembly 9. Thus, the on/off signal of the switch 4 can be transmitted to the circuit board 10, and the circuit board 10 can also transmit the control signal to the electric motion component 9.

In this embodiment, the spring of the detachment prevention lever is provided with a projection, and the switch lever is provided with a first recess and a second recess, so that the projection engages with the second recess when the on-vehicle unit is in normal use, and the detachment prevention lever is ejected after the on-vehicle unit is detached to engage the projection with the first recess. The switch can detect the working signal only when the first shift lever is within the detection range of the switch detection point 404 only when the anti-detach lever is pressed down and the convex part is engaged with the second concave part. Therefore, after the in-vehicle unit is detached, the switch cannot detect the operation signal because the convex portion cannot return to the position of engagement with the second concave portion again. Therefore, whether the vehicle-mounted unit is detached or not is recorded under the condition of no power supply through the pure mechanical detachment prevention structure.

The following is a detailed description of the operating state of the purely mechanical tamper evidence of the on-board unit:

after the on-board unit leaves the factory, the on-board unit is first mounted on the window, and the purely mechanical tamper evident device is in the first state (as shown in fig. 2). At this time, the rear housing 1 is tightly attached to the window, the window presses the pressing portion 501, so that the anti-removal rod 5 except the pressing portion 501 is located in the accommodating cavity 3, the spring 7 is in a compressed state, the convex portion 601 is clamped in the first concave portion 8011, and the first lever 802 is located below the detection point 404, that is, the switch 4 detects a non-operation signal.

After the on-board unit is installed, the on-board unit is activated, and after activation, the purely mechanical tamper-evident device in normal use is adjusted from the first state to the second state (the second state is shown in fig. 3), that is, the electric moving assembly 9 receives a control signal to push the second lever 803 upward, so that the convex portion 601 slides out of the first concave portion 8011, and the switch lever 8 moves upward to a position where the second concave portion 8012 corresponds to the convex portion 601. After the switch lever 8 is in position, the moving part 902 of the electric moving assembly 9 is reset. At this time, the rear housing 1 is tightly attached to the window, the window presses the pressing portion 501 to make all the anti-removal rod 5 except the pressing portion 501 located in the accommodating cavity 3, the spring 7 is in a compressed state, the convex portion 601 is clamped in the second concave portion 8012, the position of the first lever 802 is opposite to the detection point 404, that is, the switch 4 detects the operating signal.

After the vehicle-mounted unit is detached from the window, the purely mechanical anti-detachment device is adjusted from the second state to the third state (the third state is shown in fig. 4), namely, the rear shell 1 is separated from the window, the window no longer presses the pressing portion 501, the spring is extended under the action of the elastic force to drive the anti-detachment rod 5 to move vertically upwards, and since the convex portion 601 is clamped in the second concave portion 8012 at this time, the switch lever 8 also moves vertically upwards along with the anti-detachment rod 5. And the second driving lever 803 contacts the inner surface of the rear housing 1 during the upward movement process of the second driving lever 803, after the contact, the rear housing 1 applies a downward force to the second driving lever 803, and the detachment prevention rod 5 continues to move upward under the elastic force of the spring, so that the protrusion 601 slides out of the second recess 8012, and the detachment prevention rod 5 moves upward to a position where the protrusion 601 corresponds to the first recess 8011. At this time, the rear case 1 is separated from the window, the tamper bar 5 is extended, a part of the first link 502 is located outside the rear case 1, the spring 7 is in an extended state, the protrusion 601 is caught in the first recess 8011, the first lever 802 is located above the detection point 404, and the switch 4 detects the non-operation signal.

After the vehicle-mounted unit is reinstalled on the return window, the purely mechanical anti-dismounting device is adjusted from the third state to the first state, namely the rear shell 1 is tightly attached to the vehicle window, the vehicle window presses the pressing part 501 to enable the anti-dismounting rod 5 except the pressing part 501 to be located in the accommodating cavity 3, and the spring 7 is in a compressed state. Since the protrusion 601 is caught in the first recess 8011, the tamper bar 5 moves downward to move the switch lever 8 downward, so that the first lever 802 moves downward below the detection point 404, i.e., the switch 4 detects a non-operation signal. At this moment, because the managers can not send control signals to the electric movement assembly 9, the electric movement assembly 9 can not push the switch deflector rod 8 to move upwards, so that the purely mechanical anti-dismounting device can not be adjusted from the first state to the second state, and the switch 4 can not detect working signals, thereby realizing the effect that whether the vehicle-mounted unit is dismounted or not when the power is off.

Therefore, the purely mechanical anti-dismounting device provided by the embodiment is applied to the on-board unit, when the on-board unit is normally installed, the purely mechanical anti-dismounting device is in the second state, the switch 4 detects the working signal, and the fact that the on-board unit is not dismounted and the on-board unit is normally used can be judged. If the on-board unit is detached, the purely mechanical detachment prevention device is in a third state, the switch 4 detects a non-working signal, and the on-board unit is deactivated. And (4) reinstalling the enter window after the vehicle-mounted unit is disassembled, enabling the purely mechanical anti-disassembling device to be in the first state, and stopping the vehicle-mounted unit when detecting a non-working signal. By adopting the technical scheme provided by the embodiment, because the pure mechanical anti-dismounting device of the vehicle-mounted unit cannot return to the second state after being dismounted, even if the vehicle-mounted unit is powered off, the vehicle-mounted unit can still be judged whether to be dismounted through the signal detected by the switch 4 after being powered on again, and the problem that whether the vehicle-mounted unit cannot be dismounted when being powered off is effectively solved.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (4)

1. A purely mechanical tamper-evident device for an on-board unit, comprising:

the device comprises a rear shell (1), wherein a through hole (101) is formed in the rear shell (1);

the front shell (2), the front shell (2) and the rear shell (1) are assembled to form an accommodating cavity (3);

the switch (4), the switch (4) is arranged in the accommodating cavity (3), the switch (4) comprises a bottom (401) and a first side wall (402) and a second side wall (403) which are respectively and vertically arranged with the bottom (401), the first side wall (402) and the second side wall (403) are oppositely arranged, a detection point (404) is arranged on the surface of the first side wall (402) opposite to the second side wall (403), and/or a detection point (404) is arranged on the surface of the second side wall (403) opposite to the first side wall (402);

the anti-dismantling device comprises an anti-dismantling rod (5), wherein the anti-dismantling rod (5) is arranged in the accommodating cavity (3) and penetrates through the through hole (101), the anti-dismantling rod (5) comprises a pressing part (501), a first connecting rod (502), a blocking part (503) and a second connecting rod (504) which are sequentially connected, the pressing part (501) is positioned on the outer side of the rear shell (1), and an accommodating part (5021) is arranged on the side wall of the first connecting rod (502);

the reed (6), the reed (6) is set up in the holding part (5021), the reed (6) sets up the convex part (601) on the surface far away from the anti-disassembling rod;

one end of the spring (7) is fixed on the inner surface of the front shell (2), the second connecting rod (504) is sleeved in the spring (7), and the other end of the spring (7) is pressed on the blocking part (503);

the switch deflector rod (8), the switch deflector rod (8) is arranged in the accommodating cavity (3), the switch deflector rod (8) comprises a ring-shaped piece (801), a first deflector rod (802) and a second deflector rod (803), the first deflector rod (802) and the second deflector rod (803) are respectively arranged on the outer wall of the ring-shaped piece (802), the ring-shaped piece (801) is sleeved on the first connecting rod (502), the first deflector rod (802) is positioned between the first side wall (402) and the second side wall (403), a first concave portion (8011) and a second concave portion (8012) are arranged on the inner wall of the ring-shaped piece (801), the first concave portion (8011) and the second concave portion (8012) are sequentially arranged in the direction perpendicular to the front shell (2), and the distance between the first concave portion (8011) and the rear shell (8012) is smaller than that between the second concave portion (8012) and the rear shell (1); when the convex part (601) is clamped in the first concave part (8011), the first deflector rod (802) exceeds the detection range of the detection point (404);

the electric movement assembly (9), the electric movement assembly (9) is arranged in the accommodating cavity (3), the electric movement assembly (9) comprises a fixed part (901) and a movement part (902), the fixed part (901) is fixed on the inner surface of the front shell (2), the movement part (902) receives a control command to move in the direction vertical to the front shell (2), and the end part of the movement part (902) is opposite to the second driving lever (803);

the circuit board (10) is arranged in the accommodating cavity (3), and the circuit board (10) is electrically connected with the switch (4) and the electric movement assembly (9).

2. The device according to claim 1, characterized in that the switch (4) comprises: a mechanical push switch, a mechanical toggle switch, a photoelectric switch, or an electromagnetic switch.

3. The apparatus of claim 1, wherein a projection of the first toggle (802) on the first sidewall (402) has an area greater than an area of the detection point (404).

4. On-board unit, characterized in that it comprises a purely mechanical tamper evidence of the on-board unit according to any of claims 1 to 3.

Images