EP3255234A1

EP3255234A1 - Hinge having damping effect, and apparatus having said hinge

Info

Publication number: EP3255234A1
Application number: EP15880827.9A
Authority: EP
Inventors: Xiaodong MI; Shiping Zhu; Minyu LIN; Lin Yang
Original assignee: Midea Group Co Ltd; Guangdong Midea Kitchen Appliances Manufacturing Co Ltd
Current assignee: Midea Group Co Ltd; Guangdong Midea Kitchen Appliances Manufacturing Co Ltd
Priority date: 2015-02-06
Filing date: 2015-04-28
Publication date: 2017-12-13
Anticipated expiration: 2035-04-28
Also published as: CN104563700A; WO2016123872A1; EP3255234A4; RU2656843C1; EP3255234B1; CN104563700B

Abstract

Provided is a hinge having a damping effect, comprising a first assembly (12), a second assembly (14), a main spring (16), a connector (18), a damper assembly (20), and a connecting assembly (22); the second assembly (14) is pivotally connected to the first assembly (12), the second assembly (14) is fixedly connected to a main body, and the main spring (16) is connected to the connector (18) arranged inside the first assembly (12), and to the first assembly (12). The connector (18) connects the main spring (16) to the second assembly (14).

Description

FIELD

The present disclosure relates to a hinge, and particularly to a hinge having a buffering effect and a device having the hinge.

BACKGROUND

A hinge applied to a drop-down door of an oven at present does not have an effect of a door self-closing. That is, a manipulator is required to push or pull the door hard in whole processes of opening and closing the door, thus resulting in a poor door-closing experience.

SUMMARY

The present disclosure aims to implement a solution of a hinge of an oven having a good performance, so as to improve at least one of using effects of the hinge in the related art. Thus, the present disclosure intends to provide the hinge, which may close a door body relying on an elastic force of the hinge when the door body is closed to a certain angle, and may also achieve an automatic closing process in a gentle and noise-free manner through a damper.
The present disclosure is further to propose a device having the above hinge.
The hinge having a buffering effect according to a first aspect of preferable embodiments of the present disclosure includes a first assembly, a second assembly, a main spring, a connecting piece, a damper assembly and a connecting assembly. The first assembly and the second assembly are configured to be fixed to a device body and a drop-down door respectively and are rotatably connected by means of a first rotary shaft, so that the drop-down door is configured to be rotatably pulled downwards with respect to the device body. The first assembly is configured to be a rectangular casing and includes a first end rotatably connected with the second assembly and a second end opposite to the first end. The first assembly is provided with a guiding groove, and the second assembly includes a cam portion. The main spring is disposed in the first assembly and has a first end fixedly connected with the second end. The connecting piece is disposed in the first assembly. The connecting piece has a first end rotatably connected with the second assembly by means of a second rotary shaft and a second end connected with a second end of the main spring by means of a third rotary shaft. The third rotary shaft is rotatably and slidably disposed in the guiding groove. The connecting piece is provided with a first upper cover so as to be fitted with the first assembly to form a cavity. The damper assembly includes a damper body, an extending and retracting rod, a position limiting piece and a fixing subassembly. The damper body is located in the cavity. The extending and retracting rod extends from the damper body towards the second assembly. The position limiting piece is disposed at a top end of the extending and retracting rod. The fixing subassembly is configured to fix the damper body to the first assembly. The connecting assembly is provided between the second assembly and the extending and retracting rod. The connecting assembly includes a driven pulley and a locking spring, and the driven pulley is configured to contact the cam portion. The connecting piece is provided with a connecting shaft between the connecting assembly and the position limiting piece. The connecting shaft is configured to be driven by the connecting piece to contact the position limiting piece so as to push the position limiting piece to move in a direction towards the main spring. The second assembly has a balanced stage, a critical stage and a buffered-closing stage successively in a rotation process of the second assembly from a position where a largest opening angle is formed between the first assembly and the second assembly to the first assembly. In the balanced stage, the main spring is in a stretched state, and a tensioning force produced by the main spring is balanced with a load weight of the hinge. In the critical stage, the locking spring is in a compressed state and changes to a reset state, the connecting shaft contacts the position limiting piece so as to push the damper body in the direction towards the main spring, the main spring is in the stretched state, and the tensioning force produced by the main spring is larger than the load weight of the hinge. In the buffered-closing stage, the locking spring is in the compressed state, the extending and retracting rod is retracted into the damper body, the damper body generates a reverse buffering force, the main spring is in the stretched state and changes to the reset state, and the tensioning force produced by the main spring is larger than the load weight of the hinge.
In the hinge according to preferable embodiments of the present disclosure, as the main spring is adopted, a weight of the drop-down door may be balanced when the drop-down door is pulled downwards, thus realizing effects of stable opening and stable closing. In addition, as the damper assembly is adopted, the drop-down door may be closed automatically and slowly, thus improving a using experience of a user.
In some embodiments, the first assembly includes a bottom plate and side walls extending upwards from two sides of the bottom plate. The guiding groove is formed in each of the two side walls.
In some embodiments, the fixing subassembly includes a protruding block protruding upwards from the bottom plate and a positioning pin connecting the damper body with the first assembly. The protruding block is configured to stop the damper body so as to prevent the damper body from sliding in a direction towards the second assembly.
In some embodiments, the cavity has a rectangular shape, the damper body has a cylindrical shape, and shapes of the damper body and the cavity are matched with each other.
In some embodiments, the connecting assembly includes a connecting body, the locking spring fitted over the connecting body and the driven pulley disposed to the connecting body. The connecting body is provided with a fixed shaft, the driven pulley has an annular shape and is fitted over the fixed shaft, and the driven pulley is configured to rotatably contact the cam portion.
In some embodiments, a stopping piece fixed to the first assembly is provided between the connecting assembly and the connecting shaft, and the stopping piece is configured to stop the locking spring so as to compress the locking spring.
In some embodiments, corresponding to the balanced stage, the drop-down door is configured to rotate by an angle of 50°-70°.
In some embodiments, corresponding to the critical stage, the drop-down door is configured to rotate by an angle of 10°-15°.
In some embodiments, corresponding to the buffered-closing stage, the drop-down door is configured to rotate by an angle of 10°-25°.
The device according to a second aspect of preferable embodiments of the present disclosure includes a device body, a drop-down door and the hinge configured for the device according to the above embodiments.
In the device according to preferable embodiments of the present disclosure, as the main spring is adopted, a weight of the drop-down door may be balanced when the drop-down door is pulled downwards, thus realizing effects of stable opening and stable closing. In addition, as the damper assembly is adopted, the drop-down door may be closed automatically and slowly, thus improving a using experience of a user.
Additional aspects and advantages of embodiments of present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of embodiments of the present disclosure will become apparent and more readily appreciated from the following descriptions made with reference to the drawings, in which:

Fig. 1 is a perspective view of a hinge having a buffering effect according to an embodiment of the present disclosure;
Fig. 2 is an exploded view of a hinge having a buffering effect according to an embodiment of the present disclosure;
Fig. 3 is a sectional view of the hinge having the buffering effect in Fig. 1 along line III-III.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail and examples of the embodiments will be illustrated in the drawings, where same or similar reference numerals are used to indicate same or similar members or members with same or similar functions. The embodiments described herein with reference to drawings are explanatory, illustrative, and used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure.
In the specification, it is to be understood that terms such as "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the present disclosure be constructed or operated in a particular orientation. In addition, terms such as "first" and "second" are used herein for purposes of description and are not intended to indicate or imply relative importance or significance or to imply the number of indicated technical features. Thus, the feature defined with "first" and "second" may comprise one or more of this feature. In the description of the present disclosure, "a plurality of' means two or more than two, unless specified otherwise.
In the present specification, unless specified and defined otherwise, it is to be illustrated that the terms "mounted," "connected," "coupled" and the like are used broadly, and may be, for example, fixed connections, detachable connections, or integral connections; may also be mechanical or electrical connections; may also be direct connections or indirect connections via intervening structures; may also be inner communications or interaction relation of two elements, which can be understood by those skilled in the art according to specific situations.
In the present disclosure, unless specified or limited otherwise, a structure in which a first feature is "on" or "below" a second feature may include an embodiment in which the first feature is in direct contact with the second feature, and may also include an embodiment in which the first feature and the second feature are not in direct contact with each other, but are contacted via an additional feature formed therebetween. Furthermore, a first feature "on," "above," or "on top of' a second feature may include an embodiment in which the first feature is right or obliquely "on," "above," or "on top of' the second feature, or just means that the first feature is at a height higher than that of the second feature; while a first feature "below," "under," or "on bottom of' a second feature may include an embodiment in which the first feature is right or obliquely "below," "under," or "on bottom of' the second feature, or just means that the first feature is at a height lower than that of the second feature.
Various embodiments and examples are provided in the following description to implement different structures of the present disclosure. In order to simplify the present disclosure, certain elements and settings will be described. However, these elements and settings are only by way of example and are not intended to limit the present disclosure. In addition, reference numerals may be repeated in different examples in the present disclosure. This repeating is for the purpose of simplification and clarity and does not refer to relations between different embodiments and/or settings. Furthermore, examples of different processes and materials are provided in the present disclosure. However, it would be appreciated by those skilled in the art that other processes and/or materials may be also applied.
Referring to Fig. 1 to Fig. 3, a hinge 10 having a buffering effect according to a preferable embodiment of the present disclosure includes a first assembly 12, a second assembly 14, a main spring 16, a connecting piece 18, a damper assembly 20 and a connecting assembly 22. The first assembly 12 and the second assembly 14 are configured to be fixed to a device body and a drop-down door respectively and are rotatably connected by means of a first rotary shaft 142, so that the drop-down door may be rotatably pulled downwards with respect to the device body. The first assembly 12 is configured to be a rectangular casing and includes a first end 120 rotatably connected with the second assembly 14 and a second end 122 opposite to the first end 120. The first assembly 12 is provided with a guiding groove 124, and the second assembly 14 includes a cam portion 140. The main spring 16 is disposed in the first assembly 12 and has a first end fixedly connected with the second end 122. The connecting piece 18 is disposed in the first assembly 12. The connecting piece 18 has a first end rotatably connected with the second assembly 14 by means of a second rotary shaft 24 and a second end connected with a second end of the main spring 16 by means of a third rotary shaft 26. The third rotary shaft 26 is rotatably and slidably disposed in the guiding groove 124. The connecting piece 18 is provided with a first upper cover 180 so as to be fitted with the first assembly 12 to form a cavity 182. The damper assembly 20 includes a damper body 200, an extending and retracting rod 202, a position limiting piece 204 and a fixing subassembly 206. The damper body 200 is located in the cavity 182. The extending and retracting rod 202 extends from the damper body 200 towards the second assembly 14. The position limiting piece 204 is disposed at a top end of the extending and retracting rod 202. The fixing subassembly 206 is configured to fix the damper body 200 to the first assembly 12. The connecting assembly 22 is provided between the second assembly 14 and the extending and retracting rod 202, the connecting assembly 22 includes a driven pulley 220 and a locking spring 222, and the driven pulley 220 is configured to contact the cam portion 140. The connecting piece 18 is provided with a connecting shaft 28 between the connecting assembly 22 and the position limiting piece 204. Driven by the connecting piece 18, the connecting shaft 28 may contact the position limiting piece 204 so as to push the position limiting piece 204 to move in a direction towards the main spring 16. The second assembly 14 has a balanced stage, a critical stage and a buffered-closing stage successively in a rotation process of the second assembly 14 from a position where a largest opening angle is formed between the first assembly 12 and the second assembly 14 to the first assembly 12. In the balanced stage, the main spring 16 is in a stretched state, and a tensioning force produced by the main spring 16 is balanced with a load weight of the hinge 10. In the critical stage, the locking spring 222 is in a compressed state, the connecting shaft 28 contacts the position limiting piece 204 so as to push the damper body 200 in the direction towards the main spring 16, the main spring 16 is in the stretched state, and the tensioning force produced by the main spring 16 is larger than the load weight of the hinge 10. In the buffered-closing stage, the locking spring 222 is in the compressed state, the extending and retracting rod 202 is retracted into the damper body 200, the damper body 200 produces a reverse buffering force, the main spring 16 is in the stretched state and the tensioning force produced by the main spring 16 is larger than the load weight of the hinge 10.
In the hinge according to the preferable embodiment of the present disclosure, as the main spring 16 is adopted, it is possible to balance a weight of the drop-down door when pulling the drop-down door downwards, thus realizing stable opening and stable closing. In addition, as the damper assembly 20 is adopted, the drop-down door may be closed automatically and slowly, thus improving a using experience of a user.
Specifically, the main spring 16, the connecting piece 18, the damper assembly 20 and the connecting assembly 22 are accommodated in the first assembly 12. The first assembly 12 has a groove 128 in a bottom plate 126 thereof adjacent to the first end 120, and the groove 128 is parallel with an axial direction of the first assembly 12. The first assembly 12 and the second assembly 14 are connected by means of the first rotary shaft 142 at the first end 120. The second assembly 14 is configured to rotate relative to the first assembly 12 around the first rotary shaft 142 and also to drive the connecting piece 18 to move synchronously. The second assembly 14 is configured to swing in the groove 128 relative to the first assembly 12. The first assembly 12 is connected with a fourth rotary shaft 30 at the second end 122, and the fourth rotary shaft 30 is parallel with the first rotary shaft 142. A tail end of the connecting piece 18 away from the first end 120 is connected with a third rotary shaft 26 parallel with the fourth rotary shaft 30. The main spring 16 is connected with the third rotary shaft 26 and the fourth rotary shaft 30. The connecting piece 18 is formed integrally.
In the present embodiment, the first assembly 12 is substantially formed in a rectangular shape. The first assembly 12 includes the first end 120 and the second end 122 opposite to the first end 120. The first assembly 12 includes the bottom plate 126 and side walls 128a extending upwards from two sides of the bottom plate 126. The guiding groove 124 is provided in each of the two side walls 128a. The guiding groove 124 includes a first end point 1240 and a second end point 1242 opposite to the first end point 1240. The second assembly 14 is rotatably connected with the first assembly 12 by means of the first rotary shaft 142 and rotatably connected with the connecting piece 18 by means of the second rotary shaft 24, and the second rotary shaft 24 is parallel with the first rotary shaft 142. The connecting piece 18 is accommodated in the first assembly 12 and abuts against the two side walls 128a of the first assembly 12. The connecting piece 18 is provided with the first upper cover 180 so as to be fitted with the first assembly 12 to form the cavity 182, and the damper body 200 is located in the cavity 182. The connecting piece 18 is further provided with a second upper cover 184, and the connecting assembly 22 is located below the second upper cover 184. The second assembly 14 has a sheet shape and is inserted into the groove 128. The connecting piece 18 connects the main spring 16 with the second assembly 14, and a connecting point of the connecting piece 18 and the second assembly 14 deviates from the first rotary shaft 142 of the second assembly 14, so that the second assembly 14 may drive the connecting piece 18 to move so as to stretch the main spring 16, when the second assembly 14 rotates relative to the first assembly 12.
In the present embodiment, the fixing subassembly 206 includes a rectangular protruding block 2060 protruding upwards from the bottom plate 126 and a positioning pin 2062 connecting the damper body 200 with the first assembly 12. The damper body 200 can be stopped by the protruding block 2060, so that the damper body 200 can be prevented from sliding in the direction towards the second assembly 14.
Thus, the damper body 200 can be positioned by means of the fixing subassembly 206, which has a simple structure and is convenient to mount and detach.
In the present embodiment, the cavity 180 has a rectangular shape, the damper body 200 has a cylindrical shape, and shapes of the damper body 200 and the cavity 182 are matched with each other. The damper body 200 is provided with a return spring therein.
In the present embodiment, the connecting assembly 22 includes a connecting body 224, the locking spring 222 fitted over the connecting body 224 and the driven pulley 220 disposed to the connecting body 224. The connecting body 222 is provided with a fixed shaft 2240, the driven pulley 220 has an annular shape and is fitted over the fixed shaft 2240, and the driven pulley 220 can rotatably contact the cam portion 140. The cam portion 140 has concave and convex portions configured to be in various contacts with the driven pulley 220.
Accordingly, since the tensioning force of the main spring 16 weakens along with a decrease of an included angle between the first assembly 12 and the second assembly 14, a supplementary tensioning force is provided by the locking spring 222 of the connecting assembly 22, and the driven pulley 220 of the connecting assembly 22 contacts the cam portion 140 of the second assembly 14, so that a power source is obtained.
In the present embodiment, a stopping piece 32 fixed to the first assembly 12 is provided between the connecting assembly 22 and the connecting shaft 28, and the stopping piece 32 may stop the locking spring 222 so as to compress the locking spring 222.
The first assembly 12 is disposed to the drop-down door, and the second assembly 14 is disposed to the device body. When the hinge 10 operates, a position of the second assembly 14 is constant, and the first assembly 12 may rotate around the first rotary shaft 142 by a certain angle and drive the connecting piece 18 connected to the second assembly 14 to move synchronously, so that the main spring 16 connected to the connecting piece 18 may be stretched. Under actions of the main spring 16 and the damper assembly 20, the drop-down door may be closed automatically and slowly.
Specifically, the balanced stage represents that the hinge 10 transfers from a position n1 to a position n2, the critical stage represents that the hinge 10 transfers from the position n2 to a position n3, and the buffered-closing stage represents that the hinge 10 transfers from the position n3 to a position n4. When the second assembly 14 is located at the position n1 with respect to the first assembly 12, the hinge 10 has the largest opening angle, and the drop-down door is opened to the largest angle. When the second assembly 14 is located at the position n4 with respect to the first assembly 12, the hinge 10 has a smallest opening angle and a door body is in a closed state.
When the second assembly 14 is located at the position n1 with respect to the first assembly 12, the connecting piece 18 drives the third rotary shaft 26 to reach the first end point 1240, the main spring 16 is stretched by the connecting piece 18 so as to be in the stretched state, and the tensioning force of the main spring 16 is balanced with the load weight of the hinge 10. When the hinge 10 operates in an angle a, i.e. in the balanced stage from the position n1 to the position n2, as the tensioning force of the main spring 16 is balanced with the load weight of the hinge 10, the drop-down door may be motionless at any position in this range, in which case an external force of human is required for closing the drop-down door.
When the second assembly 14 is located at the position n2 with respect to the first assembly 12, the tensioning force of the main spring 16 is larger than the load weight of the hinge 10, the connecting shaft 28 contacts the position limiting piece 204, and the driven pulley 220 of the connecting assembly 22 contacts the cam portion 140. When the hinge 10 operates in an angle b, i.e. in the critical stage from the position n2 to the position n3, the connecting piece 18 connected with the main spring 16 slides in a direction towards the main spring 16, and the connecting shaft 28 pushes the damper body 200 in the direction towards the main spring 16, i.e. the hinge 10 may automatically drive the drop-down door to rotate rapidly in a closing direction, in which case the drop-down door may be closed automatically without the external force.
When the second assembly 14 is located at the position n3 with respect to the first assembly 12, the tensioning force of the main spring 16 is larger than the load weight of the hinge 10, and the third rotary shaft 26 is located at the second end point 1242. When the hinge 10 operates in an angle c, i.e. in the buffered-closing stage from the position n3 to the position n4, the tensioning force of the main spring 16 allows the second assembly 14 to continue rotating towards the position n4, the extending and retracting rod 202 starts to be retracted into the damper body 200, and hence the damper body 200 generates a reverse buffering force, so as to slow down a rotation speed of the door body driven by the hinge 10, so that the drop-down door rotates in a slow and uniform speed, in which case the drop-down door may be closed automatically in a gentle manner, instead of being rebounded rapidly.
When the second assembly 14 is located at the position n4 with respect to the first assembly 12, the hinge 10 has the smallest opening angle, and the door body is in the closed state. In this case, the main spring 16, the locking spring 222 and the return spring are all in the natural state.
When the hinge 10 is opened from the position n4 to any position in a range of the angle c under an action of an external force (which is usually applied by human), the damper body 200 slides in a direction towards the second assembly 14, and the return spring applies a resistance force to the damper body 200 to allow a hydraulic oil in the damper body 200 to reset. When the external force is withdrawn, as the tensioning force of the main spring 16 is larger than the load weight of the hinge 10, the drop-down door rotates in a direction towards the main spring 16, that is, the drop-down door will still be closed in a slow and uniform speed, i.e. the hinge 10 will still return to the position n4.
During an opening process of the drop-down door, i.e. a process of the hinge 10 rotating from the position n4 to the position n1, the main spring 16 is stretched from an initial state, and the locking spring 222 is compressed. Since the extending and retracting rod 202 drives the damper body 200 to move in the direction towards the second assembly 14, the return spring resets the damper body 200, and the return spring also restores to the natural state.
In the present embodiment, corresponding to the balanced stage, the hinge 10 is located at a position between the position n1 and the position n2, in which case the tensioning force produced by the main spring 16 is balanced with the load weight of the hinge 10, and thus the drop-down door may be stopped at any position in a range of the angle a. Corresponding to the balanced stage, the drop-down door is configured to rotate by an angle of 50°-70°, that is, the range of the angel a is 50°-70°.
In the present embodiment, corresponding to the critical stage, the hinge 10 is located at a position between the position n2 and the position n3, in which case the tensioning force produced by the main spring 16 is larger than the load weight of the hinge 10, and thus the hinge may rotate from the position n2 to the position n3 rapidly in a range of the angle b. Corresponding to the critical stage, the drop-down door is configured to rotate by an angle of 10°-15°, that is, the range of the angel b is 10°-15°.
In the present embodiment, corresponding to the buffered-closing stage, the hinge 10 is located at a position between the position n3 and the position n4, in which case the tensioning force produced by the main spring 16 is larger than the load weight of the hinge 10, and thus the hinge may rotate from the position n3 to the position n4 slowly in the range of the angle c. Corresponding to the buffered-closing stage, the drop-down door is configured to rotate by an angle of 10°-25°, that is, the range of the angel c is 10°-25°.
Thus, the drop-down door may be closed automatically and slowly in a designed angle range, thus improving the using experience of the user.
Certainly, numerical values above are provided as examples, so as to aid in illustrating a manner in which the automatic and slow closing of the drop-down door in a certain opening and closing angle is realized by means of the hinge 10, but are not used to limit the present disclosure.
A device in a preferable embodiment of the present disclosure includes a device body and a drop-down door. The device includes the above hinge 10. The first assembly 12 is fixedly disposed to the drop-down door, and the second assembly 14 is fixedly disposed to the device body. Optionally, the device is an oven. Certainly, the oven only serves as an example, but is not used to limit the present disclosure. Thus, the drop-down door of the device may be closed automatically and slowly, which prevents the drop-down door of the device from being damaged due to a rapid closing caused by overexertion.
Reference throughout this specification to "an embodiment," "some embodiments," "an illustrative embodiment" "an example," "a specific example," or "some examples," means 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 present disclosure. Thus, the appearances of the phrases in various places throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.
Although embodiments of the present disclosure have been shown and illustrated, it shall be understood by those skilled in the art that various changes, modifications, alternatives and variants without departing from the principle and intention of the present disclosure are acceptable. The scope of the present disclosure is defined by the claims or its equivalents.

Claims

A hinge having a buffering effect, comprising:
a first assembly and a second assembly, the first assembly having a first end rotatably connected with the second assembly and a second end opposite to the first end, the first assembly having a guiding groove, the second assembly being provided with a cam portion,

a main spring disposed in the first assembly, and having a first end fixedly connected with the second end;

a connecting piece disposed in the first assembly, the connecting piece having a first end rotatably connected with the second assembly by means of a second rotary shaft and a second end connected with a second end of the main spring by means of a third rotary shaft, the third rotary shaft being rotatably and slidably disposed in the guiding groove, the connecting piece being provided with an first upper cover so as to be fitted with the first assembly to form a cavity;

a damper assembly, comprising:
a damper body located in the cavity;

an extending and retracting rod extending from the damper body towards the second assembly;

a position limiting piece disposed at a top end of the extending and retracting rod; and

a fixing subassembly configured to fix the damper body to the first assembly; and

a connecting assembly disposed between the second assembly and the extending and retracting rod, the connecting assembly comprising a driven pulley and a locking spring, the driven pulley being configured to contact the cam portion,

wherein the connecting piece is provided with a connecting shaft between the connecting assembly and the position limiting piece, the connecting shaft is configured to be driven by the connecting piece to contact the position limiting piece so as to push the position limiting piece to move in a direction towards the main spring,

wherein the second assembly has a balanced stage, a critical stage and a buffered-closing stage successively in a rotation process of the second assembly from a position where a largest opening angle is formed between the first assembly and the second assembly to the first assembly,

in the balanced stage, the main spring is in a stretched state and changes to a reset state, and a tensioning force produced by the main spring is balanced with a load weight of the hinge;

in the critical stage, the locking spring is in a compressed state, the connecting shaft contacts the position limiting piece so as to push the damper body in the direction towards the main spring, the main spring is in the stretched state, and the tensioning force produced by the main spring is larger than the load weight of the hinge;

in the buffered-closing stage, the locking spring is in the compressed state, the extending and retracting rod is retracted into the damper body, the damper body generates a reverse buffering force, the main spring is in the stretched state and changes to the reset state, the tensioning force produced by the main spring is larger than the load weight of the hinge.
The hinge having the buffering effect according to claim 1, wherein the first assembly comprises a bottom plate and side walls extending upwards from two sides of the bottom plate, and the guiding groove is formed in each of the two side walls.
The hinge having the buffering effect according to claim 2, wherein the fixing subassembly includes a protruding block protruding upwards from the bottom plate and a positioning pin connecting the damper body with the first assembly, the protruding block is configured to stop the damper body so as to prevent the damper body from sliding in a direction towards the second assembly.
The hinge having the buffering effect according to claim 1, wherein the cavity has a rectangular shape, the damper body has a cylindrical shape, and shapes of the damper body and the cavity are matched with each other.
The hinge having the buffering effect according to claim 1, wherein the connecting assembly comprises a connecting body, the locking spring fitted over the connecting body and the driven pulley disposed to the connecting body, the connecting body is provided with a fixed shaft, the driven pulley has an annular shape and is fitted over the fixed shaft, and the driven pulley is configured to rotatably contact the cam portion.
The hinge having the buffering effect according to claim 5, wherein a stopping piece fixed to the first assembly is provided between the connecting assembly and the connecting shaft, and the stopping piece is configured to stop the locking spring so as to compress the locking spring.
The hinge having the buffering effect according to any one of claims 1 to 6, wherein corresponding to the balanced stage, a drop-down door is configured to rotate by an angle of 50°-70°.
The hinge having the buffering effect according to any one of claims 1 to 6, wherein corresponding to the critical stage, a drop-down door is configured to rotate by an angle 10°-15°.
The hinge having the buffering effect according to any one of claims 1 to 6, wherein corresponding to the buffered-closing stage, a drop-down door is configured to rotate by an angle of 10°-25°.
The hinge having the buffering effect according to claim 1, wherein the first assembly is configured as a rectangular casing.
A device, comprising a device body, a drop-down door and a hinge configured for the device according to any one of claims 1 to 10, the first assembly and the second assembly of the hinge are configured to be fixed to the device body and the drop-down door respectively and are rotatably connected by means of a first rotary shaft, so that the drop-down door is configured to be rotatably pulled downwards with respect to the device body.