Electric push rod for range hood and range hood

Abstract

The utility model discloses an electric push rod for a range hood and the range hood. The electric push rod for the range hood comprises a motor; a screw rod; the movable nut is in threaded fit with the lead screw; the first telescopic pipe is arranged on the movable nut in a sleeving mode and keeps the trend of synchronous linear movement; a housing and a dustproof sealing cover; the end, away from the movable nut, of the first telescopic pipe is sleeved with a second telescopic pipe, and the second telescopic pipe penetrates out of the dustproof sealing cover. The electric push rod further comprises a shear-shaped lever assembly, the shear-shaped lever assembly comprises a shear-shaped rod, a transmission piece, a first sliding block and a second sliding block, the first sliding block and the second sliding block are arranged on the transmission piece and can reversely and linearly move, and the shear-shaped rod is provided with tails rotationally connected with the sliding blocks. The two heads of the scissor-shaped rod abut against the first telescopic pipe and the second telescopic pipe respectively, and the distance of the scissor-shaped rod can be changed along with sliding of the sliding blocks. When the second telescopic pipe and the dustproof sealing cover are clamped, the nut can be moved to drive the transmission part to rotate, and the second telescopic pipe is jacked outwards through the head of the shear-shaped rod.

Description

TECHNICAL FIELD

[0001] The utility model relates to power device especially a kind of electric push rod for range hood and range hood with the electric push rod of application. BACKGROUND

[0002] Range hood has become the necessary household appliance in resident kitchen. With the continuous progress of technology, the function of range hood is more and more diversified. For example, the commonly used side suction type range hood is provided with a reversible smoke baffle, which is driven by an electric push rod to open and close the smoke baffle. For example, see the Chinese patent No. 201922362582.9, a submerged suction type range hood with smoke baffle, which comprises a smoke collecting hood assembly, an air inlet located at the lower part of the smoke collecting hood assembly, a smoke baffle body provided with a movable cover on the air inlet, an opening and closing mechanism provided in the smoke collecting hood assembly to turn the smoke baffle body outward to open, and a driving mechanism for driving the opening and closing mechanism. The driving mechanism can be an electric push rod hinged to one of the fixed plates. Alternatively, the lifting type range hood adjusts the height of the range hood by using an electric push rod, so that it can adapt to users with different height requirements, thereby more in line with individual use habits and improve the comfort of use. For example, see the Chinese patent No. 202022481273.6, a lifting assembly for lifting type range hood, which comprises a push rod motor, an electric push rod and a movable plate. One end of the electric push rod is connected to the output end of the push rod motor, and the other end is used to push the movable plate to move up and down. The movable plate is stacked in the smoke collecting hood of the range hood. The push rod motor is fixed to the box above the smoke collecting hood, thereby driving the smoke collecting hood to lift relative to the box.

[0003] After long-term use of the range hood, the internal parts are covered and contaminated by oil stains, which can cause the electric push rod to be stuck and unable to work. Although the electric push rod is provided with a dustproof sealing element, dust and oil accumulated into oil stains will inevitably be brought into the electric push rod during daily use. If the range hood is not used for a long time or in special circumstances, the telescopic tube and the sealing element will be stuck together. If the motor power is small, the telescopic tube will be stuck and unable to be pushed out.

[0004] Therefore, further improvement is needed. UTILITY MODEL CONTENTS

[0005] The first technical problem to be solved by the utility model is to provide an electric push rod for range hood, which can realize automatic repair after being stuck.

[0006] The second technical problem to be solved by the utility model is to provide a range hood with the above electric push rod.

[0007] The technical scheme adopted by the utility model to solve the above first technical problem is: an electric push rod for range hood, comprising:

[0008] motor;

[0009] a screw rod driven by the motor to rotate around its axis;

[0010] a moving nut sleeved on the screw rod and threadedly engaged with the screw rod so as to be linearly movable along the screw rod;

[0011] a first telescopic tube sleeved on the moving nut and kept in a synchronous linear movement;

[0012] a housing in which the screw rod and the moving nut are located, the motor being connected to one end of the housing, and the first telescopic tube being at least partially located in the housing and being linearly movable only relative to the housing; and

[0013] a dustproof sealing cover arranged at an end of the housing away from the motor; characterized in that:

[0014] an end of the first telescopic tube away from the moving nut is sleeved with a second telescopic tube, the first telescopic tube and the second telescopic tube being kept in a synchronous linear movement, and the second telescopic tube being led out from the dustproof sealing cover;

[0015] the electric push rod further comprises a scissor-shaped lever assembly arranged in the first telescopic tube, the scissor-shaped lever assembly comprising a scissor-shaped rod, a transmission member, a first sliding block and a second sliding block, the transmission member being rotatable relative to the first telescopic tube around the axis of the screw rod, the first sliding block and the second sliding block being arranged on the transmission member and being linearly movable in opposite directions along the axis of the screw rod, the scissor-shaped rod having two heads away from the respective sliding blocks and a tail rotatably connected with each sliding block, the two heads of the scissor-shaped rod being in abutment with the first telescopic tube and the second telescopic tube respectively and being capable of changing the distance with the sliding of the respective sliding blocks;

[0016] when the second telescopic tube is stuck with the dustproof sealing cover, the moving nut is capable of moving along the axis of the screw rod relative to the first telescopic tube, thereby cooperating with the transmission member to drive the transmission member to rotate and push the second telescopic tube outward through the heads of the scissor-shaped rod.

[0017] by arranging the first telescopic tube and the second telescopic tube capable of keeping synchronous movement and being relatively movable under axial external force, and arranging the scissor-shaped lever assembly, when the second telescopic tube is stuck with the dustproof sealing cover, the moving nut and the transmission member are used to cooperate, and then the two sliding blocks on the transmission member are capable of sliding towards each other through the rotation of the transmission member, so that the heads of the scissor-shaped rod are capable of pushing the second telescopic tube, the pushing force of the motor is amplified to make the second telescopic tube further move out of the housing, the automatic repair of the sticking is realized, and after the repair of the sticking, the moving nut and the second telescopic tube are automatically reset to the initial state without manual operation.

[0018] Preferably, to facilitate the opening and closing distance between the heads of the scissors-shaped rods to change with the movement of the sliders, the scissors-shaped rods comprise a first connecting rod and a second connecting rod respectively in L shape, two ends of the first connecting rod respectively constitute a head and a tail, two ends of the second connecting rod also respectively constitute a head and a tail, the first connecting rod and the second connecting rod are rotationally connected at the bending part of the L shape, the tail of the first connecting rod is rotationally connected with the first slider, and the tail of the second connecting rod is rotationally connected with the second slider.

[0019] Further, to facilitate the rotation of the transmission member to drive the two sliders to slide towards or away from each other, the transmission member comprises a transmission rod, the transmission rod is at least partially formed as a threaded structure, the threaded structure of the transmission rod is sequentially provided as a first threaded section and a second threaded section along the axial direction of the transmission rod, the screw rotation directions of the first threaded section and the second threaded section are opposite, the first slider is threadedly connected with the first threaded section, and the second slider is threadedly connected with the second threaded section.

[0020] Further, to avoid rotation of the first telescopic pipe and the moving nut in the normal working state, the first telescopic pipe is matched with the key groove of the shell, and the moving nut is kept in a trend of only synchronous linear movement with the first telescopic pipe.

[0021] Further, to ensure synchronous linear movement of the moving nut and the first telescopic pipe in the normal working state, the moving nut comprises a first part, a second part and a third part arranged coaxially in sequence, the outer diameter of the second part is smaller than that of the first part and the third part, the first telescopic pipe is sleeved on the outer periphery of the second part and the third part, the end of the third part of the moving nut adjacent to the second part is provided with a first gear, and the end of the first telescopic pipe located in the shell is provided with a second gear, the first gear and the second gear are kept in a tendency of engagement, so that the moving nut is kept in a trend of only synchronous linear movement with the first telescopic pipe.

[0022] Further, to avoid disengagement of the first telescopic pipe and the moving nut during relative linear movement, the end of the first telescopic pipe located in the shell is formed with a first annular flange protruding radially inward, the end of the third part adjacent to the second part abuts against the first annular flange of the first telescopic pipe inside the first telescopic pipe, and a first spring is arranged between the first part of the moving nut and the end of the first telescopic pipe, so that the first gear and the second gear are kept in a tendency of engagement.

[0023] In order to facilitate the transmission of the transmission member and the moving nut, the transmission member is arranged in the first telescopic pipe, the transmission member can rotate relative to the axis of the screw rod, the transmission member is arranged adjacent to the third part of the moving nut and is located on the side of the third part away from the second part, the end of the third part of the moving nut away from the second part is provided with a third gear, the transmission member comprises a fourth gear arranged at one end of the moving nut, and the third gear and the fourth gear can be engaged and separated.

[0024] In order to facilitate the resetting of the transmission member after repair, the shear lever assembly further comprises a coil spring, the outer end of the coil spring is directly or indirectly fixed with the first telescopic pipe, and the inner end of the coil spring is connected with the transmission member.

[0025] In order to facilitate the shear lever to push the second telescopic pipe, the end of the first telescopic pipe near the second telescopic pipe is formed with a second annular convex edge, the outer periphery of the end of the second telescopic pipe near the first telescopic pipe is formed with a third annular convex edge, and the two head portions of the shear lever are respectively in abutment with the second annular convex edge and the third annular convex edge.

[0026] Preferably, in order to facilitate the dustproof sealing cover to clamp the telescopic pipe and play a dustproof sealing role, the dustproof sealing cover comprises a cover body and an elastic clamp arranged in the cover body, the elastic clamp is arranged on the outer periphery of the first telescopic pipe, the elastic clamp comprises an outer ring spring sheet and an inner ring spring sheet, the outer ring spring sheet is in a wave-shaped ring shape, the inner ring spring sheet is arranged in the outer ring spring sheet, the inner ring spring sheet has at least two arc-shaped sections, the outer ring spring sheet is in abutment with the cover body, and the inner ring spring sheet is pressed inward to clamp the outer peripheral wall of the second telescopic pipe.

[0027] The utility model discloses a kind of range hood, including movable component, it is characterized in that: the electric push rod for range hood is applied as described above, to be used to drive movable component.

[0028] Compared with the prior art, the utility model has the advantages that: by setting the first telescopic pipe and the second telescopic pipe which can keep synchronous movement and relatively move under axial external force, and setting the shear lever assembly, when the second telescopic pipe and the dustproof sealing cover are stuck, the moving nut and the transmission member are cooperated, then the two sliders on the transmission member can slide towards each other by the rotation of the transmission member, so that the head of the shear lever can push the second telescopic pipe, the pushing force of motor is amplified to make the second telescopic pipe further move out of the shell, realize stuck automatic repair, and after stuck repair, the moving nut and the second telescopic pipe are automatically reset to initial state, without manual operation. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic view of the electric push rod of the utility model embodiment.

[0030] Figure 2 This is a cross-sectional view of the electric push rod according to an embodiment of the present utility model;

[0031] Figure 3 This is a schematic diagram of the hidden housing of the electric push rod according to an embodiment of the present utility model;

[0032] Figure 4 for Figure 3 A schematic diagram of the decomposed structure;

[0033] Figure 5 This is a schematic diagram of the movable nut of the electric push rod in an embodiment of the present utility model;

[0034] Figure 6 This is a schematic diagram of the first telescopic rod of the electric push rod according to an embodiment of the present utility model;

[0035] Figure 7 This is a schematic diagram of the elastic clamp of the electric push rod according to an embodiment of the present utility model;

[0036] Figure 8 This is a schematic diagram of the scissor lever assembly of the electric push rod according to an embodiment of the present utility model;

[0037] Figure 9 This is an exploded structural diagram of the scissor lever assembly of the electric push rod according to an embodiment of the present utility model;

[0038] Figure 10 This is a sectional front view (normal state) of the electric actuator according to an embodiment of the present utility model;

[0039] Figure 11 This is a sectional front view (in repair state) of the electric actuator according to an embodiment of the present utility model;

[0040] Figure 12 for Figure 10 A magnified schematic diagram of part I;

[0041] Figure 13 for Figure 11 A magnified schematic diagram of part II. Detailed Implementation

[0042] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions.

[0043] In the description of the utility model, need understanding is, the term "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" "internal", "external", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and so on the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawing, just for the convenience of describing the utility model and simplifying the description, and not indicate or imply the device or element referred to must have a particular orientation, with a particular orientation configuration and operation, because the disclosed embodiment of the utility model can be set up according to different directions, so these direction indicating terms are just as illustration and should not be regarded as limitation, for example "upper", "lower" are not necessarily limited to the direction opposite or consistent with the direction of gravity. In addition, the features defined as "first", "second" can be explicitly or implicitly include one or more features.

[0044] Referring to Figures 1-9 An electric push rod can be used for a range hood to drive movable components of the range hood to overturn, lift and the like.

[0045] The electric push rod comprises a motor 1, a shell 2, a screw rod 3, a first telescopic pipe 51, a second telescopic pipe 52, a moving nut 6 and a dustproof sealing cover 7. The motor 1 is connected to one end of the shell 2, and its output end extends into the shell 2, the motor 1 can drive the screw rod 3 to rotate around its own axis by engaging a worm wheel 81 and a worm 82. The worm 82 is coaxial with the output shaft of the motor 1, and the worm wheel 81 is fixedly arranged on the outer periphery of the screw rod 3 and rotates synchronously with the screw rod 3. The moving nut 6 is sleeved on the outer periphery of the screw rod 3 and is threadedly matched with the screw rod 3, so that when the screw rod 3 rotates, the moving nut 6 can move linearly along the screw rod 3. The worm wheel 81, the worm 82, the screw rod 3 and the moving nut 6 are all arranged in the shell 2.

[0046] The first telescopic tube 51 is located in the shell 2 when contracted and partially extends out of the shell 2 when extended, and is sleeved on the moving nut 6, both of which can relatively move along the axial direction of the screw rod 3 for a limited distance. The moving nut 6 comprises a first portion 61, a second portion 62 and a third portion 63 which are coaxially arranged in sequence and integrally formed, the outer diameter of the second portion 62 is smaller than that of the first portion 61 and the third portion 63, and the first telescopic tube 51 is sleeved on the outer periphery of the second portion 62 and the third portion 63. The first portion 61 and the second portion 62 are used for threadedly cooperating with the screw rod 3, and the third portion 63 can be arranged radially spaced apart from the screw rod 3. The end of the first telescopic tube 51 located in the shell 2 is formed with a first annular flange 511 which protrudes radially inward, and the end of the third portion 63 adjacent to the second portion 62 can abut against the first annular flange 511 of the first telescopic tube 51 inside the first telescopic tube 51, so as to prevent the moving nut 6 and the first telescopic tube 51 from being separated. A first spring 91 is arranged between the first portion 61 of the moving nut 6 and the end of the first telescopic tube 51, for avoiding relative movement of both along the axial direction of the screw rod 3 in normal state.

[0047] A limiting groove 512 is formed on the outer peripheral wall of the first telescopic tube 51, and can be matched with the key groove of the shell 2, so as to limit the rotation of the first telescopic tube 51 relative to the shell 2. The end of the third portion 63 of the moving nut 6 adjacent to the second portion 62 is provided with a first gear 64, and the first annular flange 511 of the first telescopic tube 51 is provided with a second gear 513, and in normal state, the first gear 64 and the second gear 513 are engaged under the action of the first spring 91, so as to avoid the rotation of the moving nut 6.

[0048] The dustproof sealing cover 7 is arranged at the end of the shell 2 away from the motor 1, the end of the first telescopic tube 51 away from the moving nut 6 is sleeved with a second telescopic tube 52, and the second telescopic tube 52 can be partially inserted into the first telescopic tube 51 at the end. When the first telescopic tube 51 is completely contracted in the shell 2, the end close to the dustproof sealing cover 7, and the second telescopic tube 52 extends out of the dustproof sealing cover 7 by penetrating through the dustproof sealing cover 7. The electric push rod further comprises a second spring 92 which abuts between the corresponding ends of the first telescopic tube 51 and the second telescopic tube 52, such as annular flanges arranged inside (outside) the ends of the telescopic tubes to achieve abutment with the second spring 92, so as to avoid the relative linear movement of the first telescopic tube 51 and the second telescopic tube 52 in normal condition, and only when an axial force is applied, the two can relatively linearly move.

[0049] A dustproof sealing cover 7 is arranged at the end of the housing 2 away from the motor 1, and the dustproof sealing cover 7 comprises a cover body 71 and an elastic clamp 72 arranged in the cover body 71, and the elastic clamp 72 is arranged at the outer periphery of the second telescopic tube 52. The elastic clamp 72 comprises an outer ring spring sheet 721 and an inner ring spring sheet 722, the outer ring spring sheet 721 is a wavy annular spring sheet, and the inner ring spring sheet 722 is arranged in the outer ring spring sheet 721 and has at least two sections, is arc-shaped, and is arranged in rotational symmetry. In a normal state, the outer ring spring sheet 721 abuts against the cover body 71, and the inner ring spring sheet 722 is pressed inward to clamp the outer peripheral wall of the first telescopic tube 51 or the second telescopic tube 52, so as to limit the first telescopic tube 51 and the second telescopic tube 52 to avoid shaking and avoid impurities being brought into the housing 2 by the second telescopic tube 52.

[0050] A shearing lever assembly is arranged in the first telescopic tube 51 and the second telescopic tube 52, and comprises a shearing lever 41, a transmission member 42, a first sliding block 43, a second sliding block 44 and a coil spring 45. The transmission member 42 can rotate relative to the first telescopic tube 51 about the axis of the screw rod 3, the transmission member 42 is arranged adjacent to the third part 63 of the moving nut 6 and is located on the side away from the second part 62 of the third part 63, the end of the third part 63 of the moving nut 6 away from the second part 62 is provided with a third gear 65, the transmission member 42 comprises a fourth gear 421 arranged at one end thereof facing the moving nut 6, the third gear 65 and the fourth gear 421 can be engaged and separated. The transmission member 42 further comprises a transmission disc 422 and a transmission rod 423, the transmission disc 422 is coaxially arranged with the screw rod 3, the fourth gear 421 is formed on the side of the transmission disc 422 facing the moving nut 6, and the transmission rod 423 is formed on the side of the transmission disc 422 away from the moving nut 6.

[0051] The transmission rod 423 is at least partially formed as a threaded structure, and the threaded structure of the transmission rod 423 is sequentially arranged as a first threaded section 4231 and a second threaded section 4232 along the axial direction of the transmission rod 423, the first threaded section 4231 is farther away from the transmission disc 422 than the second threaded section 4232, and the thread directions of the two threaded sections are opposite. The first sliding block 43 is threadedly connected with the first threaded section 4231, and the second sliding block 44 is threadedly connected with the second threaded section 4232. When the transmission member 42 rotates in a forward direction, the two sliding blocks move closer to each other, and when the transmission member 42 rotates in a reverse direction, the two sliding blocks move away from each other.

[0052] The scissor-shaped rod 41 comprises a first connecting rod 411 and a second connecting rod 412 which are rotatably connected, and the rotatable connection positions of the two are at the middle positions or positions close to the middle positions of the connecting rods, thus forming a scissor shape. In the embodiment, the first connecting rod 411 and the second connecting rod 412 are both substantially L-shaped rod members, and are rotatably connected at the bending positions of the L shapes. The scissor-shaped rod 41 can have multiple rotatable symmetrical arrangements, and in the embodiment, has three. The two ends of the first connecting rod 411 form the head and tail thereof respectively, and the two ends of the second connecting rod 412 also form the head and tail thereof respectively. The outer periphery of the first slider 43 is provided with a first protrusion 431, the outer periphery of the second slider 44 is provided with a second protrusion 441, the tail of the first connecting rod 411 is rotatably connected with the first protrusion 431 of the first slider 43, and the tail of the second connecting rod 412 is rotatably connected with the second protrusion 441 of the second slider 44. Thus, when the two sliders move relative to each other, the opening and closing distance between the heads of the two connecting rods can be changed.

[0053] The first telescopic tube 51 is formed with a second annular protrusion 514 at the inner periphery of the end portion close to the second telescopic tube 52, the second telescopic tube 52 is formed with a third annular protrusion 521 at the inner periphery of the end portion close to the first telescopic tube 51, the head of the first connecting rod 431 of the scissor-shaped rod 41 abuts against the third annular protrusion 521, and the head of the second connecting rod 412 of the scissor-shaped rod 41 abuts against the second annular protrusion 514.

[0054] The coil spring 45 can be arranged on the transmission disc 422 of the transmission member 42, and is used for resetting after the transmission member 42 rotates. The outer end portion of the coil spring 45 can be directly or indirectly fixed with the first telescopic tube 51, and the inner end portion of the coil spring 45 can be fixed with the transmission member 42.

[0055] Referring to Figure 10 and Figure 12 , when the electric push rod normally works, the motor 1 drives the first telescopic tube 51 and the second telescopic tube 52 to extend out of or retract into the housing 2, and the first telescopic tube 51, the second telescopic tube 52 and the moving nut 6 are relatively stationary. During the daily use of the dustproof sealing cover 7, dust and oil accumulated into oil stains are inevitably brought in by the first telescopic tube 51 and the second telescopic tube 52, and if the range hood is not used for a long time or in special situations, the second telescopic tube 52 and the elastic clamp 72 are adhered, and if the motor power is small, the second telescopic tube 52 can be stuck and cannot be pushed out. At this time, the above structure can break the adhered state of the second telescopic tube 52 and the dustproof sealing cover 7. Referring to Figure 11 、 Figure 13, first telescopic pipe 51 and second telescopic pipe 52 after sticking, running motor 1, screw rod 3 drive moving nut 6 forward (shown in the figure is to the right) a certain distance, because the first telescopic pipe 51 stuck will not be pushed by the first spring 91, the first spring 91 is gradually compressed, moving nut 6 forward after engaging with transmission member 42, moving nut 6 and the first telescopic pipe 51 is no longer engaged, moving nut 6 rotation limit release, screw rod 3 rotation drive moving nut 6 rotation, in turn drive transmission member 42 rotation, drive two sliders move towards each other, shears-shaped rod 41 head expansion, give two telescopic pipe a larger axial force, damage the second telescopic pipe 52 and dustproof seal cover 7 sticking state, while the second spring 92 stretch. Then reverse running motor 1, so that moving nut 6 back to the initial position, again with the first telescopic pipe 51 engagement, and transmission member 42 separate, the second telescopic pipe 52 thereafter can be reset under the action of the second spring 92, thus realizing the stuck repair; Or can stop running motor 1, moving nut 6 in the first spring 91 under the action of back to the initial position. Transmission member 42 rotation process coil spring 45 power storage, until the stuck repair coil spring 45 release, drive transmission member 42, shears-shaped rod 41, each slider reset.

Claims

1. An electric push rod for a range hood, comprising: a motor (1); a screw rod (3) driven by the motor (1) to rotate about its axis; a moving nut (6) sleeved on the screw rod (3) and threadedly engaged with the screw rod (3) so as to be linearly movable along the screw rod (3); a first telescopic tube (51) sleeved on the moving nut (6) and keeping a tendency of synchronous linear movement; a housing (2) in which the screw rod (3) and the moving nut (6) are located, the motor (1) being connected to one end of the housing (2), and the first telescopic tube (51) being at least partially located in the housing (2) and being linearly movable only relative to the housing (2); and a dustproof sealing cover (7) provided at an end of the housing (2) away from the motor (1); characterized in that: an end of the first telescopic tube (51) away from the moving nut (6) is sleeved with a second telescopic tube (52), the first telescopic tube (51) and the second telescopic tube (52) keep a tendency of synchronous linear movement, and the second telescopic tube (52) penetrates out of the dustproof sealing cover (7); the electric push rod further comprises a scissor-shaped lever assembly provided in the first telescopic tube (51), the scissor-shaped lever assembly comprising a scissor-shaped lever (41), a transmission member (42), a first sliding block (43) and a second sliding block (44), the transmission member (42) being rotatable relative to the first telescopic tube (51) about the axis of the screw rod (3), the first sliding block (43) and the second sliding block (44) being provided on the transmission member (42) and linearly movable in opposite directions along the axis of the screw rod (3), the scissor-shaped lever (41) having two head portions away from the respective sliding blocks and a tail portion rotatably connected with each sliding block, the two head portions of the scissor-shaped lever (41) abutting against the first telescopic tube (51) and the second telescopic tube (52) respectively and being capable of changing distance with the sliding of the respective sliding blocks; when the second telescopic tube (52) is stuck with the dustproof sealing cover (7), the moving nut (6) is linearly movable relative to the first telescopic tube (51) along the axis of the screw rod (3) so as to cooperate with the transmission member (42) to drive the transmission member (42) to rotate and to push the second telescopic tube (52) outward through the head portions of the scissor-shaped lever (41).

2. The electric push rod for a range hood according to claim 1, characterized by: The scissor-shaped lever (41) comprises a first connecting rod (411) and a second connecting rod (412) each in an L shape, two ends of the first connecting rod (411) constituting its head portion and tail portion respectively, two ends of the second connecting rod (412) also constituting its head portion and tail portion respectively, the first connecting rod (411) and the second connecting rod (412) being rotatably connected at the bending portion of the L shape, the tail portion of the first connecting rod (411) being rotatably connected with the first sliding block (43), and the tail portion of the second connecting rod (412) being rotatably connected with the second sliding block (44).

3. The electric push rod for a range hood according to claim 1, characterized by: The transmission member (42) comprises a transmission rod (423) which is at least partially configured as a threaded structure, the threaded structure of the transmission rod (423) is sequentially provided as a first threaded section (4231) and a second threaded section (4232) along the axial direction of the transmission rod (423), the thread rotation directions of the first threaded section (4231) and the second threaded section (4232) are opposite, the first sliding block (43) is threadedly connected with the first threaded section (4231), and the second sliding block (44) is threadedly connected with the second threaded section (4232).

4. The electric push rod for a range hood according to claim 1, characterized by: The first telescopic pipe (51) is matched with the key groove of the shell (2), and the moving nut (6) has a tendency to move linearly synchronously with the first telescopic pipe (51).

5. The electric push rod for a range hood according to claim 4, characterized by: The moving nut (6) comprises a first part (61), a second part (62) and a third part (63) which are coaxially and sequentially arranged, the outer diameter of the second part (62) is smaller than that of the first part (61) and the third part (63), the first telescopic pipe (51) is sleeved on the outer periphery of the second part (62) and the third part (63), the end of the third part (63) of the moving nut (6) adjacent to the second part (62) is provided with a first gear (64), the end of the first telescopic pipe (51) located in the shell (2) is provided with a second gear (513), the first gear (64) and the second gear (513) have a tendency to engage, so that the moving nut (6) has a tendency to move linearly synchronously with the first telescopic pipe (51).

6. The electric push rod for a range hood according to claim 5, characterized by: The end of the first telescopic pipe (51) located in the shell (2) is formed with a first annular flange (511) which protrudes radially inward, the end of the third part (63) adjacent to the second part (62) abuts against the first annular flange (511) of the first telescopic pipe (51) inside the first telescopic pipe (51), and a first spring (91) is arranged between the first part (61) of the moving nut (6) and the end of the first telescopic pipe (51), so that the first gear (64) and the second gear (513) have a tendency to engage.

7. The electric push rod for a range hood according to claim 5, characterized by: The transmission member (42) is arranged in the first telescopic pipe (51) and can rotate relative to the first telescopic pipe (51) around the axis of the screw rod (3), the transmission member (42) is arranged adjacent to the third part (63) of the moving nut (6) and on the side of the third part (63) away from the second part (62), the end of the third part (63) of the moving nut (6) away from the second part (62) is provided with a third gear (65), and the transmission member (42) comprises a fourth gear (421) arranged at one end thereof facing the moving nut (6), the third gear (65) and the fourth gear (421) can engage and disengage.

8. The electric push rod for a range hood according to claim 7, characterized by: The scissor-shaped lever assembly further comprises a coil spring (45), the outer end of the coil spring (45) is directly or indirectly fixed with the first telescopic pipe (51), and the inner end of the coil spring (45) is connected with the transmission member (42).

9. The electric push rod for a range hood according to any one of claims 1 to 8, characterized by: The first telescopic pipe (51) is formed with a second annular flange (514) near the inner periphery of the end of the second telescopic pipe (52), the second telescopic pipe (52) is formed with a third annular flange (521) near the outer periphery of the end of the first telescopic pipe (51), and the two head portions of the scissor-shaped rod (41) respectively abut against the second annular flange (514) and the third annular flange (521).

10. The electric push rod for a range hood according to any one of claims 1 to 8, characterized by: The dustproof sealing cover (7) comprises a cover body (71) and an elastic clamp (72) arranged in the cover body (71), the elastic clamp (72) is arranged on the outer periphery of the first telescopic pipe (51), the elastic clamp (72) comprises an outer ring spring sheet (721) and an inner ring spring sheet (722), the outer ring spring sheet (721) is in a wavy annular shape, the inner ring spring sheet (722) is arranged in the outer ring spring sheet (721), the inner ring spring sheet (722) has at least two arc-shaped sections, and the outer ring spring sheet (721) abuts against the cover body (71) to press the inner ring spring sheet (722) inwardly so as to clamp the outer peripheral wall of the second telescopic pipe (52).

11. A range hood comprising a movable component, characterized in that: The electric push rod for a range hood according to any one of claims 1 to 10 is used to drive a movable component.

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