CN112373936B

CN112373936B - Urea tank cover assembly and urea tank

Info

Publication number: CN112373936B
Application number: CN202011239352.4A
Authority: CN
Inventors: 张贵华; 李冠霖; 尹燕升; 朱宏志; 邢喜春; 贾昭远
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2020-11-09
Filing date: 2020-11-09
Publication date: 2022-09-06
Anticipated expiration: 2040-11-09
Also published as: CN112373936A

Abstract

The invention relates to the technical field of urea tanks, and discloses a urea tank cover assembly and a urea tank. Wherein urea cover assembly includes: a housing; a cover is turned; the lock assembly comprises a lock body and a lock cylinder, the lock body is arranged in the shell and is in threaded connection with the tank body, and the lock cylinder is arranged in the lock body; inject first sealed chamber in the lock body, press from both sides between lock body and the shell and be equipped with seal assembly, lock body, shell and seal assembly enclose into the sealed chamber of second, are equipped with the intercommunicating pore that feeds through first sealed chamber and the sealed chamber of second on the lock body, and when urea cover assembly screwed up on the jar body, the sealing ring on the jar body just is to the intercommunicating pore so that first sealed chamber is isolated with the sealed chamber of second. When the urea tank cover assembly disclosed by the invention is screwed on the tank body, gas in the tank body can be prevented from entering the second sealing cavity through the communication hole, the sealing property between the urea tank cover assembly and the tank body in the transportation process is ensured, and the sealing assembly can prevent the gas from overflowing from the upper end of the second sealing cavity when the first sealing cavity is communicated with the second sealing cavity.

Description

Urea tank cover assembly and urea tank

Technical Field

The invention relates to the technical field of urea tanks, in particular to a urea tank cover assembly and a urea tank.

Background

The urea jar that has now includes urea cover assembly and jar body, and urea cover assembly can dismantle with jar body and be connected, and jar body is used for saving urea solution, because the internal gas pressure of jar is higher than a standard atmospheric pressure in the transportation, consequently must be sealing connection between urea cover assembly and the jar body, however there is the poor problem of sealing performance in the most existing urea jar for current urea jar suitability is relatively poor.

Disclosure of Invention

Based on the above, the invention aims to provide a urea tank cover assembly and a urea tank, and solves the problem that the applicability of the urea tank is poor due to poor sealing performance between the urea tank cover assembly and a tank body in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

a urea tank cover assembly, comprising: a housing; the flip cover is rotatably arranged on the shell; the lock assembly comprises a lock body and a lock cylinder, the lock body is arranged in the shell and is in threaded connection with the tank body, the lock cylinder is arranged in the lock body, and the axial direction of the lock cylinder is the same as that of the shell; the urea tank cover assembly is screwed down on the tank body, and a sealing ring on the tank body is right aligned to the communication hole so that the first sealed cavity is isolated from the second sealed cavity.

As a preferred scheme of urea cover assembly, be equipped with sealed the pad on the flip and follow the first arch that the periphery of sealed pad set up, be equipped with the second arch on the shell, the flip lock is in when on the shell, sealed pad clamp is located flip with between the second arch, just the second arch is followed first bellied periphery is distributed.

As a preferable scheme of the urea tank cover assembly, an annular groove is formed in the inner wall of the lock body, the annular groove is located below the sealing component, the communication holes are formed in the annular groove, the number of the communication holes is at least two, and the at least two communication holes are distributed along the circumferential direction of the lock body.

As a preferred scheme of urea cover assembly, be equipped with the seal groove on the outer wall of lock body, seal assembly installs in the seal groove, seal assembly includes first sealing washer and second sealing washer, first sealing washer, second sealing washer and the shell encloses into the V die cavity.

As a preferred scheme of the urea tank cover assembly, when the lock assembly is in a locking state, the shell and the lock cylinder idle in a clockwise direction and a counterclockwise direction relative to the lock body simultaneously; when the lock assembly is in the open state, the shell and the lock cylinder simultaneously slide relative to the lock body in one direction of the clockwise direction and the anticlockwise direction, and the urea tank cover assembly can be detached in the other direction.

As a preferred scheme of the urea tank cover assembly, a lock tongue is arranged on the lock cylinder, lock teeth are arranged on the inner wall of the lock body along the circumferential direction, when the lock assembly is in an open state, the lock tongue is over against the lock teeth, when a screwing torque is equal to or greater than a first preset torque, the shell and the lock cylinder can slip along the clockwise direction relative to the lock body, and the urea tank cover assembly can be detached along the counterclockwise direction; when the lock assembly is in a locked state, the lock bolt is separated from the lock teeth, the shell and the lock cylinder simultaneously idle along the clockwise direction and the anticlockwise direction relative to the lock body, the idle torque is equal to or smaller than a second preset torque, and the second preset torque is smaller than the first preset torque.

As a preferred scheme of urea cover assembly, be equipped with ear on the lock core, be equipped with on the shell along two at least strengthening ribs that self axial set up, wherein two the strengthening rib with form the reinforcing groove between the shell, the ear is located the reinforcing groove.

As a preferred scheme of a urea tank cover assembly, one of the shell and the lock body is provided with a connecting bulge, the other lock body is provided with an annular sliding groove which is arranged corresponding to the connecting bulge, and when the lock assembly is in a locking state and rotates the shell, the connecting bulge slides in the annular sliding groove.

Preferably, the outer shell is provided with a holding part which penetrates through the outer shell along the radial direction, and the holding part is used for being held by a user.

The urea tank comprises a tank body, a sealing ring and the urea tank cover assembly in any scheme, wherein the urea tank cover assembly is in threaded connection with the tank body, and the sealing ring is arranged on the tank body.

The invention has the beneficial effects that: when the urea tank cover assembly disclosed by the invention is screwed on the tank body, the sealing ring on the tank body can prevent gas in the tank body from entering the second sealing cavity through the communicating hole, so that the sealing property between the urea tank cover assembly and the tank body in the transportation process is ensured, and the added sealing assembly can prevent the gas from overflowing from the upper end of the second sealing cavity when the first sealing cavity is communicated with the second sealing cavity.

The sealing ring additionally arranged on the urea tank can isolate the first sealing cavity from the second sealing cavity when the urea tank cover assembly is screwed on the tank body, the lock body is screwed from the tank body when the urea tank cover assembly is dismounted, the communication hole moves upwards along with the urea tank cover assembly, the first sealing cavity is gradually communicated with the second sealing cavity, and gas in the tank body is discharged to the outside from the lower end of the second sealing cavity.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a partially broken away view of a urea tank cover assembly provided in accordance with an embodiment of the present invention;

FIG. 2 is a top view of a urea tank cover assembly;

FIG. 3 is a cross-sectional view at A-A of FIG. 2;

FIG. 4 is a schematic view of FIG. 2 at B-B;

figure 5 is a schematic view of a lock body provided in accordance with an embodiment of the present invention in one orientation;

figure 6 is a schematic view of a lock body according to an embodiment of the present invention in another orientation;

FIG. 7 is a schematic illustration of a urea tank cover assembly provided in accordance with an embodiment of the present invention;

FIG. 8 is a bottom view of the housing provided by an exemplary embodiment of the present invention;

fig. 9 is a schematic view of a lock cylinder.

In the figure:

1. a housing; 11. a second protrusion; 12. reinforcing ribs; 120. a reinforcing groove; 13. a connecting projection; 14. a holding part;

21. a cover is turned; 211. a first protrusion; 22. a gasket;

3. a lock assembly; 30. a lock hole; 31. a lock body; 3101. a first sealed chamber; 3102. a communicating hole; 3103. an annular groove; 3104. a sealing groove; 3105. an annular chute; 311. a lock case; 3111. locking teeth; 312. a lock body; 32. a lock cylinder; 321. a latch bolt; 322. an ear portion;

4. a seal assembly; 401. a second sealed chamber; 402. a V-shaped cavity; 41. a first seal ring; 42. and a second seal ring.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, 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 given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

As shown in fig. 1 to 9, the present embodiment provides a urea tank cover assembly, which includes a housing 1, a flip cover 21 and a lock assembly 3, where the flip cover 21 is rotatably disposed on the housing 1, the flip cover 21 can rotate 160 ° at most relative to the housing 1, the lock assembly 3 includes a lock body 31 and a lock cylinder 32, the lock body 31 is disposed in the housing 1 and is in threaded connection with a tank body, the lock cylinder 32 is disposed in the lock body 31, and an axial direction of the lock cylinder 32 is the same as an axial direction of the housing 1. A first sealed cavity 3101 with an open end is defined in the lock body 31, the first sealed cavity 3101 is communicated with the tank body, a sealing component 4 is clamped between the lock body 31 and the shell 1, the lock body 31, the shell 1 and the sealing component 4 enclose a second sealed cavity 401, the lower end of the second sealed cavity 401 is communicated with the outside, a communication hole 3102 for communicating the first sealed cavity 3101 with the second sealed cavity 401 is arranged on the lock body 31, and when the urea tank cover assembly is screwed on the tank body, the sealing ring on the tank body is over against the communication hole 3102 to isolate the first sealed cavity 3101 from the second sealed cavity 401.

Specifically, the lock body 31 of the present embodiment is made of a urea corrosion resistant material, as shown in fig. 3 and 4, the lock body 31 includes a lock housing 311 and a lock body 312, an upper end of the lock housing 311 and an upper end of the lock body 312 are connected together by laser welding, a first sealed cavity 3101 with an open lower end is formed between the upper end and the upper end, an internal thread is disposed on an inner wall of the lock body 31, an external thread corresponding to the internal thread is disposed on the tank body, and the lock body 31 is in threaded connection with the tank body. The lock case 311, the housing 1 and the seal assembly 4 form a second sealed chamber 401 having an open lower end, and the lower end of the second sealed chamber 401 is communicated with the outside.

Further, as shown in fig. 3, a sealing groove 3104 is provided on an outer wall of the lock body 31 of the present embodiment, and the sealing assembly 4 is installed in the sealing groove 3104, as shown in fig. 4, the sealing assembly 4 includes a first sealing ring 41 and a second sealing ring 42, and the first sealing ring 41, the second sealing ring 42 and the housing 1 enclose a V-shaped cavity 402. The first sealing ring 41 and the second sealing ring 42 of this embodiment are integrally formed pieces, and a V-shaped groove is formed on the integrally formed pieces, and the V-shaped groove and the housing 1 enclose a V-shaped cavity 402.

When the urea tank cover assembly provided by the embodiment is screwed on the tank body, the sealing ring on the tank body can prevent gas in the tank body from entering the second sealing cavity 401 through the communication hole 3102, so that the sealing property between the urea tank cover assembly and the tank body in the transportation process is ensured, and the additionally arranged sealing component 4 can prevent the gas from overflowing from the upper end of the second sealing cavity 401 when the first sealing cavity 3101 is communicated with the second sealing cavity 401.

As shown in fig. 1, the flip cover 21 of the present embodiment is provided with a sealing pad 22 and a first protrusion 211 disposed along an outer periphery of the sealing pad 22, as shown in fig. 3, the housing 1 is provided with a second protrusion 11, when the flip cover 21 is fastened on the housing 1, the sealing pad 22 is sandwiched between the flip cover 21 and the second protrusion 11, and the second protrusion 11 is distributed along an outer periphery of the first protrusion 211. The added first protrusion 211 and second protrusion 11 can not only prevent dust from falling into the urea tank cover assembly, but also prevent gas from entering the lock assembly 3 to corrode the lock cylinder 32 of the urea tank cover assembly.

As shown in fig. 3 and 4, the lock body 31 of this embodiment has an annular groove 3103 on the inner wall, the annular groove 3103 is located below the sealing assembly 4, the communication holes 3102 are arranged on the annular groove 3103, the number of the communication holes 3102 is four, and the four communication holes 3102 are uniformly distributed along the circumferential direction of the lock body 31, so that the gas in the tank body simultaneously enters the second sealing chamber 401 from the four communication holes 3102 and is discharged to the external environment. In other embodiments, the number of the communication holes 3102 may be other numbers, and may be specifically set according to actual needs.

Specifically, when the lock assembly 3 is in the locked state, the housing 1 and the lock cylinder 32 can be simultaneously idly rotated in the clockwise direction and the counterclockwise direction with respect to the lock body 31; when the lock assembly 3 is in the open state, the housing 1 and the lock cylinder 32 can simultaneously slip in a clockwise direction relative to the lock body 31, and the urea tank cover assembly can be removed in a counterclockwise direction. In other embodiments, it is also possible that when the lock assembly 3 is in the unlocked state, the housing 1 and the lock cylinder 32 are simultaneously slid in the counterclockwise direction with respect to the lock body 31, and the urea tank cover assembly can be removed in the clockwise direction.

Further, as shown in fig. 9, a lock tongue 321 is arranged on the lock cylinder 32, as shown in fig. 5, a lock tooth 3111 is arranged on the inner wall of the lock body 31 along the circumferential direction, when the lock assembly 3 is in an open state, the lock tongue 321 faces the lock tooth 3111, when the tightening torque is equal to or greater than a first preset torque, the housing 1 and the lock cylinder 32 can slip in the clockwise direction relative to the lock body 31, and the urea tank cover assembly can be detached in the counterclockwise direction; when the lock assembly 3 is in the locked state, the bolt 321 is disengaged from the lock tooth 3111, the housing 1 and the lock cylinder 32 idle simultaneously in the clockwise direction and the counterclockwise direction relative to the lock body 31, and the idle torque is equal to or smaller than the second preset torque which is smaller than the first preset torque.

Specifically, be equipped with inclined plane and right-angle face on the spring bolt 321, when lock subassembly 3 is in the state of opening and lock core 32 rotates along with shell 1 along the clockwise, the inclined plane and the lock tooth 3111 contact of spring bolt 321 for lock core 32 can slide along the clockwise for lock tooth 3111, when lock subassembly 3 is in closure state and lock core 32 rotates along with shell 1 along the anticlockwise, the right-angle face and the lock tooth 3111 contact of spring bolt 321, lock core 32 can drive lock body 31 and slide along the anticlockwise, thereby make urea cover assembly can follow jar and pull down. In the embodiment, the first preset torque is 1.7N · m, the second preset torque is 0.1N · m, and when the urea tank cover assembly is screwed on the tank body, the screwing torque is smaller than the first preset torque, so that the urea tank cover assembly can be screwed on the tank body, that is, the urea tank cover assembly can be in threaded connection with the tank body. In other embodiments, the magnitudes of the first preset torque and the second preset torque are not limited to this limitation of the present embodiment, and are specifically set according to actual needs.

It should be noted that, as shown in fig. 7, a lock hole 30 is arranged on the lock assembly 3, when the lock assembly 3 is in an open state, the position of the lock hole 30 is as shown in fig. 7, at this time, the latch bolt 321 is directly opposite to the lock tooth 3111, when the housing 1 is rotated clockwise, the housing 1 and the lock cylinder 32 can slip clockwise relative to the lock body 31, at this time, the latch bolt 321 slides along the lock tooth 3111, when the housing 1 is rotated counterclockwise, the latch bolt 321 on the lock cylinder 32 can be attached to the lock tooth 3111, at this time, the urea tank cover assembly can be detached from the tank body. On the basis of fig. 7, the key is used to rotate the lock hole 30 by 90 ° in the clockwise direction, the lock assembly 3 is changed from the unlocked state to the locked state, at this time, the lock tongue 321 is disengaged from the lock tooth 3111, and the housing 1 and the lock cylinder 32 idle in the clockwise direction and the counterclockwise direction with respect to the lock body 31 at the same time, so as to achieve the anti-theft effect. For user management, the key to unlock or lock the lock assembly 3 is the same as that of the entire vehicle ignition or the like.

As shown in fig. 9, the lock core 32 of the present embodiment is provided with two ears 322, as shown in fig. 8, the housing 1 is provided with four reinforcing ribs 12 arranged along its own axial direction, wherein two reinforcing ribs 12 form a reinforcing groove 120 with the housing 1, another two reinforcing ribs 12 form a reinforcing groove 120 with the housing 1, and the two ears 322 are respectively located in the two reinforcing grooves 120. Because ear 322 is located reinforcing groove 120, lock core 32 can rotate along with shell 1 is synchronous when rotatory shell 1, because the internal gas pressure of jar is higher, the phenomenon that shell 1 was damaged because of external force is too big can be prevented when dismantling urea cover assembly to the strengthening rib 12 that adds takes place.

Further, as shown in fig. 8, the housing 1 of the present embodiment is provided with two connecting protrusions 13 along the circumferential direction, as shown in fig. 5, the lock body 31 is provided with an annular sliding groove 3105 corresponding to the two connecting protrusions 13, when the lock assembly 3 is in the locked state and the housing 1 is rotated, the connecting protrusions 13 slide in the annular sliding groove 3105, that is, the idle torque at this time is used for overcoming the resistance of the connecting protrusions 13 in the annular sliding groove 3105. In other embodiments, the lock body 31 may further include a connecting protrusion 13, the inner wall of the housing 1 is provided with an annular sliding slot 3105 corresponding to the connecting protrusion 13, and the connecting protrusion 13 can slide in the annular sliding slot 3105.

As shown in fig. 7, the outer shell 1 of the present embodiment is provided with a holding portion 14 penetrating the outer shell 1 in the radial direction, and the holding portion 14 is used for being held by a user, so that the user can conveniently screw the urea tank cover assembly on the tank body or dismount the urea tank cover assembly from the tank body. Specifically, the two sides of the holding portion 14 are designed to be circular arcs, so that the holding portion is convenient for a user to hold, when the urea tank cover assembly is installed, the urea tank cover assembly can be installed on the tank body by holding the holding portion 14, and when the gas pressure in the tank body is high and the urea tank cover assembly is not easy to detach from the tank body, the user holds the shell 1 tightly to detach the shell.

The embodiment also provides a urea tank, which comprises a tank body (not shown), a sealing ring (not shown) and the urea tank cover assembly, wherein the urea tank cover assembly is screwed on the tank body, and the sealing ring is arranged on the tank body.

The sealing ring that the urea jar that this embodiment provided is add can make first sealed chamber 3101 and second sealed chamber 401 isolated when the urea cover assembly is screwed up on the jar body, screws up lock body 31 soon from the jar body during the dismantlement, and the intercommunicating pore 3102 moves upwards along with urea cover assembly, and first sealed chamber 3101 and second sealed chamber 401 communicate gradually, and the internal gas of jar is discharged into the external world from the lower extreme of second sealed chamber 401.

The urea tank of this embodiment is provided with an exhaust valve (not shown in the figure) disposed at the upper end of the urea tank. When the urea tank cover assembly is installed on the tank body and locked with the lock assembly 3, the urea tank runs along with the whole vehicle, the first sealing cavity 3101 is filled with 0.7MPa of compressed air and urea solution, when the vehicle stops running, the exhaust valve is firstly opened to reduce the pressure of the urea tank, but the pressure in the urea tank after pressure reduction is still higher than the outside, at the moment, the urea tank cover assembly is rotated, the communication hole 3102 moves upwards along with the urea tank cover assembly, the first sealing cavity 3101 is gradually communicated with the second sealing cavity 401, and the gas in the tank body is discharged into the outside from the lower end of the second sealing cavity 401.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the particular embodiments described herein, and that various obvious changes, rearrangements and substitutions will now be apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A urea tank cover assembly, comprising:

a housing (1);

a flip cover (21) rotatably disposed on the housing (1);

the lock assembly (3) comprises a lock body (31) and a lock cylinder (32), the lock body (31) is arranged in the shell (1) and is in threaded connection with the tank body, the lock cylinder (32) is arranged in the lock body (31), and the axial direction of the lock cylinder (32) is the same as that of the shell (1);

inject open first sealed chamber of one end (3101) in the lock body (31), first sealed chamber (3101) with jar body intercommunication, lock body (31) with it is equipped with seal assembly (4) to press from both sides between shell (1), lock body (31) shell (1) reaches seal assembly (4) enclose into the sealed chamber of second (401), the lower extreme and the external world intercommunication in the sealed chamber of second (401), be equipped with the intercommunication on lock body (31) first sealed chamber (3101) with intercommunicating pore (3102) in the sealed chamber of second (401), urea cover assembly is screwed up when the jar body is gone up, the sealing ring on the jar body is just right intercommunicating pore (3102) so that first sealed chamber (3101) with the sealed chamber of second (401) is isolated.

2. The urea tank cover assembly according to claim 1, wherein the flip cover (21) is provided with a sealing gasket (22) and a first protrusion (211) disposed along the periphery of the sealing gasket (22), the housing (1) is provided with a second protrusion (11), when the flip cover (21) is fastened to the housing (1), the sealing gasket (22) is sandwiched between the flip cover (21) and the second protrusion (11), and the second protrusion (11) is distributed along the periphery of the first protrusion (211).

3. The urea tank cover assembly according to claim 1, wherein an annular groove (3103) is formed on the inner wall of the lock body (31), the annular groove (3103) is located below the sealing component (4), the communication holes (3102) are formed on the annular groove (3103), the number of the communication holes (3102) is at least two, and the at least two communication holes (3102) are distributed along the circumferential direction of the lock body (31).

4. The urea tank cover assembly according to claim 1, wherein a sealing groove (3104) is formed on an outer wall of the lock body (31), the sealing assembly (4) is installed in the sealing groove (3104), the sealing assembly (4) comprises a first sealing ring (41) and a second sealing ring (42), and the first sealing ring (41), the second sealing ring (42) and the outer shell (1) enclose a V-shaped cavity (402).

5. The urea tank cover assembly according to claim 1, wherein when the lock assembly (3) is in the locked state, the housing (1) and the lock cylinder (32) are simultaneously idled in clockwise and counterclockwise directions with respect to the lock body (31); when the lock assembly (3) is in an open state, the shell (1) and the lock cylinder (32) simultaneously slide relative to the lock body (31) in one direction of the clockwise direction and the anticlockwise direction, and the urea tank cover assembly can be detached in the other direction.

6. The urea can cover assembly according to claim 5, wherein a locking tongue (321) is arranged on the lock cylinder (32), a locking tooth (3111) is arranged on the inner wall of the lock body (31) along the circumferential direction, when the lock assembly (3) is in an open state, the locking tongue (321) is opposite to the locking tooth (3111), when the tightening torque is equal to or greater than a first preset torque, the shell (1) and the lock cylinder (32) can slide along the clockwise direction relative to the lock body (31), and the urea can cover assembly can be detached along the anticlockwise direction; when the lock assembly (3) is in a locking state, the lock bolt (321) is separated from the lock teeth (3111), the shell (1) and the lock cylinder (32) simultaneously rotate in the clockwise direction and the anticlockwise direction relative to the lock body (31), the rotating torque is equal to or smaller than a second preset torque, and the second preset torque is smaller than the first preset torque.

7. The urea tank cover assembly according to claim 6, wherein the lock cylinder (32) is provided with an ear portion (322), the outer shell (1) is provided with at least two reinforcing ribs (12) arranged along the axial direction of the outer shell, two reinforcing ribs (12) form a reinforcing groove (120) with the outer shell (1), and the ear portion (322) is located in the reinforcing groove (120).

8. The urea tank cover assembly according to claim 7, wherein one of the housing (1) and the lock body (31) is provided with a connecting protrusion (13), and the other is provided with an annular sliding groove (3105) corresponding to the connecting protrusion (13), and when the lock assembly (3) is in the locked state and the housing (1) is rotated, the connecting protrusion (13) slides in the annular sliding groove (3105).

9. The urea tank cover assembly according to claim 1, wherein the outer shell (1) is provided with a gripping portion (14) extending radially through the outer shell (1), the gripping portion (14) being adapted to be gripped by a user.

10. A urea tank comprising a tank body, a sealing ring, and a urea tank cover assembly as recited in any one of claims 1-9, wherein the urea tank cover assembly is threadably attached to the tank body, and the sealing ring is disposed on the tank body.