Range hood

Abstract

The utility model discloses a range hood which comprises an upper box body and a lower box body, a smoke collecting cavity with an opening in the bottom surface is formed in the smoke collecting hood; the fan is arranged in the upper box body, a first channel is formed between the fan and the rear side wall surface of the upper box body, and a second channel is formed between the fan and the front side wall surface of the upper box body; and a top smoke inlet; the top face, forming the smoke collecting cavity, of the smoke collecting hood comprises a first top plate, a third channel is formed between the first top plate and the bottom of the draught fan, the top smoke inlet is formed in the rear side of the third top plate, and the first top plate gradually inclines downwards from front to back, so that the sectional area of the third channel is gradually reduced from back to front.

Description

TECHNICAL FIELD

[0001] The utility model relates to an oil fume purification device, especially an oil fume extractor. BACKGROUND

[0002] The oil fume extractor has become one of the kitchen household electrical appliances in modern families. At present, the oil fume extractor has various forms, including side suction type, top suction type and "7" type with top and side double suction. For example, the oil fume extractor disclosed in Chinese patent No. 201920169144.8 comprises a cabinet, an accommodating cavity is arranged inside the cabinet, an air inlet and an air outlet are arranged on the accommodating cavity; a smoke collecting hood comprising a horizontal air guiding part and a vertical air guiding part arranged at a certain angle with each other, the horizontal air guiding part is provided with a top smoke inlet, the vertical air guiding part is provided with a side smoke inlet, the smoke flowing out of the horizontal air guiding part and the vertical air guiding part enters the air inlet; a fan system arranged inside the accommodating cavity, comprising: a fan wheel; a first smoke inlet and a second smoke inlet arranged at two ends of the fan wheel; and a smoke exhaust port in communication with the first smoke inlet and the second smoke inlet, the smoke flowing into the first smoke inlet and the second smoke inlet through the top smoke inlet and the side smoke inlet is exhausted through the smoke exhaust port.

[0003] The above-mentioned fan is a double-air-inlet centrifugal fan oil fume extractor, the oil fume is not fully utilized for the flow guiding effect of the smoke collecting hood when entering the first smoke inlet on the front side of the fan, the oil fume flow rate is slow, and the oil fume extraction effect is poor. UTILITY MODEL CONTENTS

[0004] The utility model solves the technical problems of the prior art, provides an oil fume extractor, and utilizes the smoke collecting hood to form an acceleration channel to promote the oil fume on the rear side of the acceleration channel to be guided forward and be rapidly sucked in.

[0005] The utility model solves the above-mentioned technical problems by adopting the following technical scheme: an oil fume extractor, comprising:

[0006] an upper cabinet;

[0007] a smoke collecting hood, a smoke collecting cavity with an open bottom surface is formed in the smoke collecting hood;

[0008] a fan arranged in the upper cabinet, a first channel is formed between the fan and the rear wall surface of the upper cabinet, a second channel is formed between the fan and the front wall surface of the upper cabinet; and

[0009] a top smoke inlet; characterized in that:

[0010] The top surface of the smoke collecting hood forming the smoke collecting cavity comprises a first top plate, a third channel is formed between the first top plate and the bottom of the fan, the top smoke inlet is arranged at the rear side of the third top plate, and the first top plate gradually inclines downward from front to rear, so that the cross-sectional area of the third channel gradually decreases from rear to front.

[0011] Since the oil fume has a long path from the top smoke inlet to the second channel, the third channel forms a Venturi channel, so that the oil fume entering the range hood from the rear side of the third channel can accelerate into the second channel at the front side along the third channel to promote the oil fume to be sucked into the fan from the second channel, thereby improving the oil fume suction effect.

[0012] Further, the fan comprises a first air inlet as a main air inlet towards the rear side and a second air inlet as a secondary air inlet towards the front side, the depth of the first channel is D1, the depth of the second channel is D2, and the following relationship is satisfied: 1≤D1 / D2≤8. While ensuring smoothness of the first channel at the back, the ventilation of the second channel at the front side is also considered, the air inlet path of the first channel at the rear side is relatively shorter than that at the front side, and the oil fume suction efficiency is higher.

[0013] Further, the fan comprises a first air inlet as a main air inlet towards the rear side and a second air inlet as a secondary air inlet towards the front side, the depth of the second channel is D2, the height between the rear end of the first top plate and the bottom of the fan is L1, the height between the front end of the first top plate and the bottom of the fan is L2, and the following relationship is satisfied: 1≤L2 / D2≤4. While ensuring smoothness of the first channel at the back, the ventilation of the second channel at the front side is also considered, the air flow is limited to turn at the front side without too much change in cross-sectional area, and the loss caused by sudden change is avoided.

[0014] Preferably, the fan comprises a volute, the volute comprises oppositely arranged first and second cover plates, the first cover plate is located at the rear side of the second cover plate, the first channel is formed between the first cover plate and the rear side wall surface of the upper box body, the second channel is formed between the second cover plate and the front side wall surface of the upper box body, and the third channel is formed between the bottom of the volute and the first top plate.

[0015] Further, the area of the projection of the volute on the horizontal plane is S4, the area of the overlapping projection of the volute and the first top plate on the horizontal plane is S5, and the following relationship is satisfied: S5 / S4≥60%. The overlapping ratio of the projection areas limits the positional relationship between the volute and the smoke hood, to a certain extent limits the positional relationship between the backside oil fume entry point and the first air inlet of the fan, thereby limiting the movement path of the oil fume, and further improving the oil fume suction effect; meanwhile, the end point distance of the oil fume along the upper surface of the first top plate guided by the third channel at the front side is limited, thereby limiting the positional relationship between the oil fume after separating from the front side smoke guiding surface and the second air inlet of the volute at the front side, thereby limiting the movement path of the oil fume, and further improving the oil fume suction effect.

[0016] Further, the intersection of the first top plate and the third top plate is projected on the horizontal plane within the projection of the second channel on the horizontal plane, so that the oil fume can be diverted into the second channel under the guidance of the first top plate.

[0017] Further, the top surface of the smoke hood constituting the smoke collecting cavity further comprises a second top plate and a third top plate, the second top plate is gradually inclined downward from the back end of the first top plate, the third top plate is gradually inclined downward from the front end of the first top plate, and the height of the smoke collecting cavity gradually increases from front to back and then gradually decreases. The smoke collecting cavity arranged as above can have good flow guiding effect and oil guiding effect, so that the oil liquid adsorbed on the surface of the smoke hood can be gathered and collected backward along the first top plate and the second top plate, and flow downward along the second part of the inner wall surface, thereby avoiding flowing down from the front surface of the front panel.

[0018] Further, the top smoke inlet comprises a first smoke inlet part, and the first smoke inlet part is located outside the smoke collecting cavity and behind the smoke collecting cavity. The first smoke inlet is located downstream of the whole smoke collecting cavity, so that the oil fume has sufficient buffer space, the oil fume is buffered in the smoke collecting cavity to reduce turbulence, and then smoothly reaches the top smoke inlet after flowing out from the back side of the smoke collecting cavity.

[0019] Further, in order to increase the smoke inlet area and ensure that the oil fume quickly passes through the top smoke inlet, the top smoke inlet further comprises a second smoke inlet part, and the second smoke inlet part is located below the first smoke inlet part.

[0020] Further, the range hood further comprises a first folded edge constituting the first smoke inlet portion and a second folded edge constituting the second smoke inlet portion, the first folded edge and the second folded edge are both perforated plate members, the first folded edge extends downward from the rear end of the smoke collecting hood, and the second folded edge extends forward from the lower end of the first folded edge. By arranging the first folded edge, the first smoke inlet portion can be conveniently constituted, and oil on the upper surface of the smoke collecting cavity can be guided downward; by arranging the second folded edge, the second smoke inlet portion can be conveniently constituted, so that oil smoke that has not been guided to the first smoke inlet portion is prevented from accumulating and forming a vortex, and the oil smoke is guided out in time, thereby preventing the oil smoke from affecting the normal discharge of the oil smoke from the first smoke inlet portion and the noise that may be caused thereby; meanwhile, oil on the first folded edge can be guided downward, so that the oil is prevented from splashing in the smoke collecting box.

[0021] Compared with the prior art, the range hood has the advantages that: since the oil smoke has a long path from the top smoke inlet to the second channel, the third channel forms a Venturi channel, so that the oil smoke entering the range hood from the rear side of the third channel can accelerate along the third channel to enter the front side of the second channel, thereby promoting the oil smoke to be sucked into the fan from the second channel, and improving the oil smoke suction effect. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 FIG. 1 is a schematic view of a range hood of an embodiment of the present application (side smoke inlet closed);

[0023] Figure 2 FIG. 2 is a sectional perspective view of the range hood of the embodiment of the present application (side smoke inlet closed);

[0024] Figure 3 FIG. 3 is a sectional view of the range hood of the embodiment of the present application (side smoke inlet closed); Figure 2

[0025] Figure 4 FIG. 4 is a sectional side view of the range hood of the embodiment of the present application (side smoke inlet closed);

[0026] Figure 5 FIG. 5 is a sectional view of the range hood of the embodiment of the present application, in which the upper box body and the fan are hidden;

[0027] Figure 6 FIG. 6 is a sectional view of the range hood of the embodiment of the present application, in which the upper box body and the fan are hidden; Figure 5

[0028] Figure 7 FIG. 7 is a schematic view of the range hood of the embodiment of the present application (side smoke inlet open). DETAILED DESCRIPTION

[0029] ​​The technical solutions in the embodiments of the present specification will be described clearly and completely in the embodiments of the present specification in combination with the drawings in the embodiments of the present specification. Obviously, the described embodiments are only part of the embodiments of the present specification, rather than all the embodiments. Based on the embodiments in the present specification, all other embodiments obtained by those skilled in the art without creative work belong to the scope of the present specification.

[0030] It should be noted that the terms "first", "second" and the like in the description and claims of the present specification and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present specification described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or server including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0031] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numbers in the drawings represent functionally identical or similar elements. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0032] The word "exemplary" is used herein in the sense of being an example, illustration, or demonstration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0033] The term "and / or" herein is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality, for example, including at least one of A, B and C can mean including any one or more elements selected from the set consisting of A, B and C.

[0034] The specific angles, heights, widths and other numerical values given in the specific embodiments below are all corresponding to the corresponding measurements of the specific drawings.

[0035] In addition, for a better understanding of the present disclosure, numerous specific details are given in the following detailed description. One skilled in the art will understand that the present disclosure can be practiced without certain specific details. In some instances, well-known methods, structures, elements, and circuits have not been described in detail in order to avoid obscuring the subject matter.

[0036] Referring to Figures 1-7 An extractor hood comprises an upper cabinet 1 and a smoke collecting cabinet 2 connected below the upper cabinet 1, the smoke collecting cabinet 2 comprises a first part 21 extending transversely and a second part 22 extending longitudinally, the distance between the front end of the first part 21 and the wall surface on which the extractor hood is installed is 370mm, so that the user will not feel oppressed and the probability of collision is reduced, the second part 22 extends downward from the rear side of the first part 21. Thus, the smoke collecting cabinet 2 as a whole forms a "7" shape. The second part 22, the first part 21 and the upper cabinet 1 are sequentially in fluid communication.

[0037] The first part 21 comprises a smoke collecting cover 211, which can be formed as the whole of the first part 21 or as a part of the first part 21. The second part 22 has a front panel 221, which can be gradually inclined backward from top to bottom, and the front panel 221 is usually formed by a glass panel and a metal panel support.

[0038] The smoke collecting cover 211 forms a smoke collecting cavity 2111 with an open bottom, which serves as a smoke collecting buffer. The top of the smoke collecting cover 211 forming the smoke collecting cavity 2111 comprises a first top plate 2112, a second top plate 2113 and a third top plate 2114, wherein the first top plate 2112 is gradually inclined downward from front to back, the third top plate 2114 is gradually inclined downward from front to back from the front end of the first top plate 2112, and the second top plate 2113 is gradually inclined downward from back to front from the rear end of the first top plate 2112 (in the installed state of the extractor hood, "front" refers to the side close to the user, and "back" refers to the side close to the installed wall surface). The rear end of the second top plate 2113 is located at the rear side of the front panel 221 of the second part 22. The shape of the above-mentioned smoke collecting cavity 2111 can achieve good flow guiding effect (to be described in detail below) and oil guiding effect, so that the oil liquid adsorbed on the surface of the smoke collecting cover 211 is gathered and collected backward along the first top plate 2112 and the second top plate 2113, and flows downward along the inner wall of the second part 22, avoiding flowing down from the front surface of the front panel 221.

[0039] The smoke collecting cavity 2111 is mostly located at the front side of the front panel 221 of the second part 22, and is at least partially located at the back side of the front panel 221. The first part 21 has a top smoke inlet arranged outside the smoke collecting cavity 2111, which is located at the back side of the front panel 221 and is also lower than the smoke collecting cavity 2111. In this way, the user can achieve the hiding of the top smoke inlet in the front view in the on-hook state, avoid frequent cleaning of the exposed part, and also improve the overall aesthetics, achieving the full-hidden top smoke inlet effect of the range hood. Moreover, it can provide sufficient buffer space for the oil fume, so that the oil fume is buffered in the smoke collecting cavity 2111 to reduce turbulence, and then smoothly reaches the top smoke inlet after flowing out from the back side of the smoke collecting cavity 2111. If the top smoke inlet is arranged inside the smoke collecting cavity 2111, the oil fume will immediately enter the top smoke inlet after hitting the top of the smoke collecting cavity 2111, and the flow direction of the oil fume at the top smoke inlet will be very chaotic, thereby affecting the oil fume extraction effect.

[0040] The overall height of the smoke collecting cavity 2111 arranged in the above manner gradually increases from front to back and then gradually decreases.

[0041] The plane where the bottom of the smoke collecting cavity 2111 is located, i.e., the bottom surface of the smoke collecting cavity 2111, is Figure 5 In the cross-sectional view shown by the dashed line M2, each top plate is an equal-thickness plate member, the surface is a plane, the included angle between the third top plate 2114 and the plane M2 is α, and 20°≤α≤60° is satisfied. The included angle between the second top plate 2113 and the plane M2 is β, and 30°≤β≤80° is satisfied. The inclination of the second top plate 2113 and the third top plate 2114 is relatively gentle and extends a certain width, so that the oil fume in front of the smoke collecting hood 211 can enter the smoke collecting cavity 2111 gently and be guided to the top smoke inlet at the back. Otherwise, the third top plate 2114 has a relatively large inclination, and the oil fume entering the smoke collecting cavity 2111 from the front of the smoke collecting hood 211 will quickly turn after hitting the first top plate 2112, causing airflow turbulence, and the oil fume will escape from the front. At the same time, the second top plate 2113 also has a certain inclination, so that the oil fume can smoothly transition from the smoke collecting cavity 2111 to the top smoke inlet.

[0042] The top smoke inlet is not higher than the front panel 211. In this embodiment, the top smoke inlet is formed by the first folded edge 212 and the second folded edge 213, both of which are open plate structures. The first folded edge 212 extends downward from the rear end of the smoke hood 211 (the smoke collecting cavity 2111 is usually formed by stretching, so the rear end of the smoke hood 211 is a stretching plane located behind the rear end of the second top plate 2113, rather than the rear end of the second top plate 2113. The plane where the rear end of the smoke hood 211 is located is the bottom surface M2 of the smoke collecting cavity 211 described above). The second folded edge 213 is located below the first folded edge 212 and extends forward from the lower end of the first folded edge 212 to the rear surface of the front panel 221. The front end of the second folded edge 213 extends downward to form a third folded edge 214. The third folded edge 214 is tightly attached to the inner surface of the front panel 221 of the second part 22 and is fixed to the front panel 221. The smoke hood 211, the first folded edge 212, the second folded edge 213, and the third folded edge 214 can be integrally formed.

[0043] The acute angle between the second folded edge 213 and the horizontal plane M1 is θ, and θ≥0°, more preferably θ≥12°, so as to facilitate the downward guidance of oil flowing down the first folded edge 212. The third folded edge 214 is parallel to the front panel 221 of the second part 22, which can ensure more contact area after installation with the front panel 221, guarantee subsequent welding with the left and right connecting structures, and better support the front panel 221, and better support the front panel 221 during user cleaning and pressing.

[0044] As described above, the first folded edge 212 and the second folded edge 213 are both open plate structures. The first folded edge 212 has at least two first smoke inlets 2121 arranged in the left-right direction of the range hood, and the second folded edge 213 has at least two second smoke inlets 2131 arranged in the left-right direction of the range hood. The first folded edge 212 forms a first smoke inlet part of the top smoke inlet, and the second folded edge 213 forms a second smoke inlet part of the top smoke inlet. Through the arrangement of the smoke inlets as described above, on the one hand, the air inlet area requirement is guaranteed, thereby guaranteeing the performance and oil fume suction effect, and on the other hand, the interval arrangement of the smoke inlets relative to the overall long strip smoke inlet arrangement has better strength, improves the stability of the structure and the consistency of the part material state, thereby guaranteeing the reliability of the oil fume suction effect.

[0045] Since the first smoke inlet hole 2121 is located at the rear side of the smoke collecting cavity 2111 and below the smoke collecting cavity 2111, after part of the oil fume flows out of the smoke collecting cavity 2111 (is guided backward and downward), the oil fume flows out of the first smoke inlet hole 2121 smoothly backward, and after turning upward inside the first part 21, enters the fan 3 arranged in the upper cabinet 1, which can reduce the loss caused by the flow direction mutation of the oil fume passing through the first smoke inlet hole 2121. A small part of the oil fume passes through the second smoke inlet hole 2131 into the second part 22, and the oil fume entering the second part 22 rises upward, and the arrangement of the second smoke inlet hole 2131 can avoid the oil fume that has not been guided to the first smoke inlet hole 2121 from accumulating in the space formed by the first folding edge 212, the second folding edge 213 and the front panel 221 to generate vortex, and timely guide this part of the oil fume out to avoid affecting the normal discharge of the oil fume from the first smoke inlet hole 2121 and the noise that may be caused thereby.

[0046] The front panel 221 of the second part 22 of the smoke collecting cabinet 2 is provided with a side smoke inlet 222, and the oil fume mainly enters the smoke collecting cabinet 2 from the side smoke inlet 222. The oil fume that is not sucked into the side smoke inlet 222 rises upward until it reaches the smoke collecting cavity 2111 and is sucked in from the top smoke inlet. A smoke baffle 4 can be arranged on the smoke collecting cabinet 2, which can open and close the side smoke inlet 222. In the embodiment, the smoke baffle 4 is opened and closed in a flip motion, and the closed state is shown in Figure 1 , and the open state is shown in Figure 7 .

[0047] The upper cabinet 1 is provided with a fan 3. In the embodiment, the fan 3 includes a volute 31, an impeller 32 arranged in the volute 31, and a motor 33 for driving the impeller 32 to rotate. The volute 31 includes oppositely arranged first and second cover plates 311 and 312, and the first cover plate 311 is located at the rear side of the second cover plate 312. The fan 3 is a double-inlet centrifugal fan, which includes a first inlet 341 facing the rear side and a second inlet 342 facing the front side. The first inlet 341, as a main inlet, is arranged on the first cover plate 311, and the second inlet 342, as a secondary inlet, is arranged on the second cover plate 312, forming a back suction form. The first channel Q1 is formed between the first cover plate 311 and the rear side wall surface of the upper cabinet 1, and the second channel Q2 is formed between the second cover plate 312 and the front side wall surface of the upper cabinet 1. The depth (size in the front-rear direction) of the first channel Q1 is D1, and the depth of the second channel Q2 is D2. The third channel Q3 is formed between the first top plate 2112 of the smoke collecting hood 211 and the bottom of the volute 31. Since the bottom of the volute 31 is substantially horizontal, and the first top plate 2112 is inclined, the cross-sectional area of the third channel Q3 gradually decreases from the rear to the front, and the flow direction of the second channel Q2 and the third channel Q3 changes suddenly at the intersection, i.e., the oil fume flow direction changes from the rear to the front in the third channel Q3 to the upward flow in the second channel Q2. Since the oil fume enters the top smoke inlet and has a long path before reaching the second channel, the third channel Q3 forms a Venturi channel, so that the oil fume can accelerate along the third channel Q3 and enter the second channel Q2 from the front side after entering the range hood from the rear side of the third channel Q3, thereby promoting the oil fume to be sucked into the fan 3 from the second channel Q2.

[0048] Based on the overall size of the range hood and the size limitation of the volute 31, the three channels formed by the positional relationship of the volute 31 and the smoke collecting hood 211 will affect the overall oil fume suction efficiency, effect and noise. The height between the rear end of the first top plate 2112 and the bottom of the volute 31 (fan 3) is L1, and the height between the front end of the first top plate 2112 and the bottom of the volute 31 (fan 3) is L2. In the back suction scheme, the first channel Q1 at the back is ensured to be smooth, and the ventilation of the second channel Q2 at the front is also considered to avoid the gap being too small to cause the noise level to rise due to the sudden change of the flow path through the narrow slit, and the size needs to satisfy the following relationship: 1≤L2 / D2≤4, 1≤D1 / D2≤8. Among them, 1≤L2 / D2≤4 can limit the flow turning at the front side without too much cross-sectional area change, and 1≤D1 / D2≤8 mainly limits the working condition of back suction. The air inlet path of the first channel Q1 at the back is relatively shorter than that at the front, and has higher oil fume suction efficiency.

[0049] The volute 31 is arranged in a horizontal plane (Figure 4 The orthogonal projection area on the horizontal plane M1 (shown as a dashed line M1 in the sectional view) is S4, and the projection direction is shown by the arrow F1 in the figure Figure 4 The overlapping area of the projection of the volute 31 and the first top plate 2112 on the horizontal plane M1 is S5, and S5 / S4≥60% is satisfied. The projection area overlap ratio limits the positional relationship between the volute 31 and the smoke hood 211, to a certain extent, limits the positional relationship between the backside oil fume entry point and the first air inlet 341 of the fan 3, thereby limiting the movement path of the oil fume, and further improving the oil fume suction effect; at the same time, the distance from the end point of the oil fume guided along the upper surface of the first top plate 2112 through the third channel Q3 is limited at the front side, thereby limiting the positional relationship between the oil fume after separating from the front side guide surface and the second air inlet 342 at the front side of the volute, thereby limiting the movement path of the oil fume, and further improving the oil fume suction effect. The intersection of the first top plate 2112 and the third top plate 2114 is projected on the projection of the second channel Q2 on the horizontal plane M1, so that the oil fume can be guided by the first top plate 2112 to enter the second channel Q2.

[0050] The oil liquid on the lower surface of the smoke hood 211 is collected to the back end, part of which flows along the front surface of the first folded edge 212 and the upper surface of the second folded edge 213, passes through the second smoke inlet hole 2131 to flow along the lower surface of the second folded edge 213, part of which passes through the first smoke inlet hole 2121 to flow along the back surface of the first folded edge 212 and the lower surface of the second folded edge 213, and then flows downward along the third folded edge 214 and the back surface of the front panel 221, until it is collected into the oil cup 5 arranged at the bottom of the smoke collection box 2. The oil liquid dropped onto the upper surface of the smoke hood 211 is collected to the back end, and flows along the back surface of the first folded edge 212 and the lower surface of the second folded edge 213, and then flows downward along the third folded edge 214 and the back surface of the front panel 221, until it is collected into the oil cup 5 arranged at the bottom of the smoke collection box 2. When the oil liquid passes through the second smoke inlet hole 2131 of the second folded edge 213, even if it drips from the second smoke inlet hole 2131, it is collected inside the second part 22.

[0051] In the present embodiment, a top-side double-suction range hood is shown. Alternatively, the above-mentioned smoke collection cavity structure can also be used in a top-suction range hood. In addition, the top smoke inlet can also be arranged on the second top plate 2113, as long as it is located behind the first top plate 2112.

[0052] The "fluid communication" in the utility model refers to the spatial position relation between two components or parts (hereinafter collectively referred to as a first part, a second part), that is, fluid (gas, liquid or mixture of both) can flow or / and be transported from the first part to the second part along the flow path, which can be directly connected between the first part and the second part, or indirectly connected between the first part and the second part through at least one third party, which can be a fluid passage such as a pipeline, a channel, a conduit, a flow guide, a hole, a groove, etc., or a chamber allowing fluid to flow or a combination thereof.

Claims

1. A range hood, comprising: an upper cabinet (1); a hood (211) in which a hood cavity (2111) with a bottom opening is formed; a fan (3) disposed in the upper cabinet (1), the fan (3) and a rear side wall surface of the upper cabinet (1) forming a first passage (Q1), the fan (3) and a front side wall surface of the upper cabinet (1) forming a second passage (Q2); and a top smoke inlet; characterized in that: the top surface of the hood (211) forming the hood cavity (2111) includes a first top plate (2112), the first top plate (2112) and a bottom of the fan (3) forming a third passage (Q3), the top smoke inlet being disposed at a rear side of the third passage (Q3), the first top plate (2112) being inclined downward from front to rear, so that a cross-sectional area of the third passage (Q3) gradually decreases from rear to front.

2. The hood according to claim 1, characterized in that: the fan (3) includes a first air inlet (341) toward the rear side as a main air inlet and a second air inlet (342) toward the front side as a sub air inlet, a depth of the first passage (Q1) is D1, a depth of the second passage (Q2) is D2, and the following relationship is satisfied: 1≤D1 / D2≤8.

3. The hood according to claim 1, characterized in that: the fan (3) includes a first air inlet (341) toward the rear side as a main air inlet and a second air inlet (342) toward the front side as a sub air inlet, a depth of the second passage (Q2) is D2, a height between a rear end of the first top plate (2112) and the bottom of the fan (3) is L1, a height between a front end of the first top plate (2112) and the bottom of the fan (3) is L2, and the following relationship is satisfied: 1≤L2 / D2≤4.

4. The hood according to claim 1, characterized in that: the fan (3) includes a volute (31) including a first cover plate (311) and a second cover plate (312) disposed opposite to each other, the first cover plate (311) being located at a rear side of the second cover plate (312), the first passage (Q1) being formed between the first cover plate (311) and the rear side wall surface of the upper cabinet (1), the second passage (Q2) being formed between the second cover plate (312) and the front side wall surface of the upper cabinet (1), and the third passage (Q3) being formed between a bottom of the volute (31) and the first top plate (2112).

5. The hood according to claim 4, characterized in that: an area of a normal projection of the volute (31) on a horizontal plane (M1) is S4, an area of an overlapping portion of projections of the volute (31) and the first top plate (2112) on the horizontal plane (M1) is S5, and the following relationship is satisfied: S5 / S4≥60%.

6. The hood according to claim 1, characterized in that: a projection of an intersection of the first top plate (2112) and a third top plate (2114) on the horizontal plane (M1) is located within a projection of the second passage (Q2) on the horizontal plane (M1).

7. The hood according to claim 1, characterized in that: The top surface of the smoke collecting hood (211) constituting the smoke collecting cavity (2111) further comprises a second top plate (2113) and a third top plate (2114), the second top plate (2113) is gradually inclined downward from the rear side end of the first top plate (2112), the third top plate (2114) is gradually inclined downward from the front side end of the first top plate (2112), and the height of the smoke collecting cavity (2111) gradually increases from front to rear and then gradually decreases.

8. The hood according to claim 7, characterized in that: The top smoke inlet comprises a first smoke inlet portion, and the first smoke inlet portion is located outside the smoke collecting cavity (2111) and behind the smoke collecting cavity (2111).

9. The hood according to claim 7, characterized in that: The top smoke inlet further comprises a second smoke inlet portion, and the second smoke inlet portion is located below the first smoke inlet portion.

10. The hood according to claim 9, characterized in that: The range hood further comprises a first folded edge (212) constituting the first smoke inlet portion and a second folded edge (213) constituting the second smoke inlet portion, the first folded edge (212) and the second folded edge (213) are both perforated plate members, the first folded edge (212) extends downward from the rear side end of the smoke collecting hood (211), and the second folded edge (213) extends forward from the lower end of the first folded edge (212).

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