CN220044916U - Heat-insulating sealing cavity structure of shell - Google Patents

Abstract

The utility model discloses a shell heat-insulating sealing cavity structure, which comprises: a housing; a heating body for heating the aerosol-generating substrate; a first accommodating cavity is arranged in the shell and is used for accommodating the heating body; the first accommodating cavity is configured to form a closed cavity to prevent heat generated by the heating body from diffusing to the outside of the first accommodating cavity. According to the shell heat-insulating sealed cavity structure, the first accommodating cavity for accommodating the heating body is configured as the airtight cavity, and heat generated by the heating body is difficult to exchange with the outside, so that heat loss generated by the heating body can be reduced, the heat utilization efficiency of the shell heat-insulating sealed cavity structure is improved, and meanwhile, the heat generated by the heating body is convenient to accurately control.

Description

Heat-insulating sealing cavity structure of shell

Technical Field

The utility model relates to the technical field of heating smoking set production, in particular to a shell heat-insulating sealing cavity structure.

Background

The housing insulating sealed cavity structure releases the compound by heating rather than burning the smoking material. The heating body is arranged in the heat-insulating sealing cavity structure of the shell, and can generate a large amount of heat under the condition that the power supply device supplies power. However, the temperature difference exists between the heating body and the space around the heating body, so that part of heat generated by the heating body can be lost to the space around the heating body, and the heat utilization efficiency of the heat-insulating sealing cavity structure of the shell is low. Meanwhile, the heat generated by the heating body is not easy to precisely control.

Accordingly, there is a need for a housing heat insulating seal chamber structure.

Disclosure of Invention

The utility model aims to provide a shell heat-insulating sealing cavity structure which solves the problems in the prior art and can reduce the heat loss generated by a heating body.

The utility model provides a shell heat-insulating sealing cavity structure, which comprises:

a housing;

a heating body for heating the aerosol-generating substrate;

a first accommodating cavity is arranged in the shell and is used for accommodating the heating body; the first accommodating cavity is configured to form a closed cavity so as to prevent heat generated by the heating body from diffusing to the outside of the first accommodating cavity.

The heat-insulating sealed cavity structure of the shell, wherein the heat-insulating sealed cavity structure of the shell preferably further comprises a bracket accommodated in the shell; the first receiving cavity is formed by the bracket construction.

A housing heat insulating sealed cavity structure as described above, wherein preferably said bracket includes an upper end wall, a lower end wall and side walls defining said first receiving cavity; the heating body is longitudinally abutted between the upper end wall and the lower end wall along the shell; the side wall is provided with a plurality of bosses, and at least part of the outer surface of the heating body is abutted against the bosses.

In the above-mentioned heat-insulating sealed cavity structure of a housing, preferably, a second accommodating cavity is further provided in the housing, the second accommodating cavity is formed by the bracket structure, and at least part of the second accommodating cavity is used for accommodating a battery; the first receiving cavity and the second receiving cavity are separated by the side wall.

The heat-insulating sealed cavity structure of the shell, as described above, preferably further comprises a control module arranged in the shell, wherein the control module comprises a first PCBA and a second PCBA, a micro control unit and a switch assembly are arranged on the first PCBA, the first PCBA is arranged at a position close to the battery, and the battery is electrically connected with the first PCBA; the second PCBA is arranged at a position close to the heating body, and a charging interface is arranged on the second PCBA; the switch component is provided with an electric quantity indicator lamp; the first PCBA and the second PCBA are connected through a flexible circuit board.

The heat-insulating sealed cavity structure of the shell as described above, wherein preferably, the heating body comprises an upper connecting seat and a lower connecting seat; the upper connecting seat is abutted against the upper end wall; the lower connecting seat is clamped on the lower end wall; the upper connecting seat and the lower connecting seat are sleeved with sealing sleeves.

The heat-insulating sealed cavity structure of the shell as described above, wherein preferably, the heating body comprises a heating pipe; the heating body further comprises a vacuum heat-insulating pipe arranged around the heating pipe.

The shell heat-insulating sealing cavity structure, wherein the heating body comprises a heating assembly, a temperature measuring assembly and a heat-insulating assembly, and the heating assembly comprises a base pipe, and a heating element is arranged on the inner wall or the outer wall of the base pipe; the temperature measuring component comprises a temperature measuring element arranged at the periphery of the heating component and a heat shrinkage tube sleeved outside the temperature measuring element; the heat insulation assembly is coated outside the heating assembly and comprises a heat insulation pipe with vacuum and an outer sleeve arranged outside the heat insulation pipe.

A housing heat insulating sealed cavity structure as described above, wherein preferably the interior cavity of the base tube is configured as a heating chamber for receiving the aerosol-generating substrate, the heating chamber having oppositely disposed first and second openings; the aerosol-generating substrate is inserted into the interior of the heating chamber through the first opening; at least a portion of the second opening defines an air inlet.

The heat-insulating sealing cavity structure of the shell, which is described above, preferably further comprises an air inlet pipe and a sealing plug arranged in the air inlet pipe; an end of the aerosol-generating substrate abuts the sealing plug; a gap between the sealing plug and the air inlet pipe forms an air inlet channel communicated with the air inlet; the intake passage extends in a longitudinal direction of the housing, and an intake cross-sectional area of the intake passage remains unchanged.

According to the shell heat-insulating sealed cavity structure, the first accommodating cavity for accommodating the heating body is configured as the airtight cavity, and heat generated by the heating body is difficult to exchange with the outside, so that the loss of the heat generated by the heating body can be reduced, the heat utilization efficiency of the shell heat-insulating sealed cavity structure is improved, and meanwhile, the heat generated by the heating body is also convenient to accurately control.

Drawings

For the purpose of making the objects, technical solutions and advantages of the present utility model more apparent, the present utility model will be further described with reference to the accompanying drawings, in which:

FIG. 1 is a schematic perspective view of an embodiment of a heat-insulating sealed cavity structure of a housing according to the present utility model;

FIG. 2 is a perspective view of an embodiment of a housing heat-insulating sealed cavity structure provided by the present utility model after opening the right bracket;

FIG. 3 is an exploded view of a heating element of an embodiment of a heat-insulating sealed cavity structure of a housing provided by the utility model;

FIG. 4 is a perspective view of a bracket of an embodiment of a housing heat-insulating sealed cavity structure provided by the utility model;

FIG. 5 is a schematic perspective view of a left bracket of an embodiment of a heat-insulating sealed cavity structure of a housing provided by the utility model;

FIG. 6 is a cross-sectional view of an embodiment of a housing heat-insulating sealed cavity structure provided by the present utility model;

fig. 7 is an enlarged layout of fig. 6.

Reference numerals illustrate: 10-shell, 11-first accommodating cavity, 12-second accommodating cavity, 20-heating body, 200-aerosol-generating substrate, 21-substrate tube, 212-heating cavity, 22-heat insulation component, 221-heat insulation tube, 222-outer sleeve, 24-upper connecting seat, 25-lower connecting seat, 26-temperature measuring element, 27-sealing plug, 28-first opening, 29-second opening, 30-battery, 40-control module, 41-switch component, 50-bracket, 541-upper end wall, 542-lower end wall, 543-side wall, 55-boss, 60-air inlet and 61-air inlet pipe.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative, and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments should be construed as exemplary only and not limiting unless otherwise specifically stated.

"first", "second", as used in this disclosure: and similar words are not to be interpreted in any order, quantity, or importance, but rather are used to distinguish between different sections. The word "comprising" or "comprises" and the like means that elements preceding the word encompass the elements recited after the word, and not exclude the possibility of also encompassing other elements. "upper", "lower", etc. are used merely to denote relative positional relationships, which may also change accordingly when the absolute position of the object to be described changes.

In this disclosure, when a particular element is described as being located between a first element and a second element, there may or may not be intervening elements between the particular element and the first element or the second element. When it is described that a specific component is connected to other components, the specific component may be directly connected to the other components without intervening components, or may be directly connected to the other components without intervening components.

All terms (including technical or scientific terms) used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs, unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods, and apparatus should be considered part of the specification.

As shown in fig. 1 to 7, the heat-insulating seal cavity structure of a housing provided in this embodiment includes:

a housing 10;

a heating body 20 for heating the aerosol-generating substrate 200;

a first accommodating cavity 11 is arranged in the shell 10, and the first accommodating cavity 11 is used for accommodating the heating body 20; wherein the first receiving chamber 11 is configured to form a closed chamber to prevent heat generated from the heating body 20 from diffusing to the outside of the first receiving chamber 11.

The heat-insulating sealed cavity structure of the shell is used for heating the aerosol-generating substrate 200, such as a cigarette which is approximately in a rod shape, and the aerosol is generated after the cigarette is heated by the heat-insulating sealed cavity structure of the shell. The tobacco or tobacco leaf extract is included in the cigarette.

Further, as shown in fig. 2, the housing 10 is further provided with a battery 30 and a control module 40, where the battery 30 and the heating body 20 are electrically connected with the control module 40, and the control module 40 is further provided with a switch assembly, and when the user starts the switch assembly, the battery 30 can provide power for the heating body 20. In some embodiments of the utility model, the housing heat-insulating sealed cavity structure is substantially box-shaped, and has a smaller overall length, which is convenient for a user to hold. The heating body 20 and the battery 30 are arranged side by side in the inner cavity of the housing 10 as two components with larger volumes.

Further, the housing heat-insulating sealed cavity structure further comprises a bracket 50 accommodated in the housing 10; the first accommodating cavity 11 is formed by the bracket 50, and the bracket 50 is convenient for fixedly mounting the heating body 20, the battery 30 and the control module 40, specifically, the bracket 50 is divided into a plurality of accommodating cavities, which can respectively accommodate the heating body 20, the battery 30 and the control module 40. In some embodiments of the present utility model, the bracket 50 includes a left bracket and a right bracket, and in particular embodiments, after the heating body 20, the battery 30, and the control module 40 are mounted inside the receiving chamber on the left bracket, the right bracket is fixedly coupled to the left bracket by screws. After assembly, the entire bracket is placed into the interior cavity of the housing 10 through the open end of the housing 10.

A portion of the inner cavity of the holder 50 is configured to form a first receiving chamber 11 for receiving the heating body 20. In order to reduce the heat loss of the heating body 20, the first receiving chamber 11 is constructed to form a closed chamber so that the heat generated from the heating body 20 is difficult to be diffused to the outside of the first receiving chamber 11. Specifically, as shown in fig. 5, the bracket 50 includes an upper end wall 541, a lower end wall 542, and a side wall 543 that define the first housing chamber 11; wherein the heating body 20 is abutted between the upper end wall 541 and the lower end wall 542 in the longitudinal direction of the housing 10; the side wall 543 is provided around the main body portion of the heating body 20.

In operation, since the first housing chamber 11 for housing the heating body is configured as a closed chamber, heat generated by the heating body 20 is difficult to exchange with the outside, so that loss of heat generated by the heating body 20 can be reduced.

Further, as shown in fig. 5, the side wall 543 is provided with a plurality of bosses 55, at least a portion of the outer surface of the heating body 20 abuts against the bosses 55, and the bosses 55 are mainly used for abutting against the outer surface of the heating body 20, so that the heating body 20 can be stably accommodated in the first accommodating cavity 11. The bosses 55 are substantially arc-shaped, and the bosses 55 are longitudinally spaced along the housing 10, and it should be noted that the number and distribution of the bosses 55 are not particularly limited in the present utility model.

Still further, a second accommodating cavity 12 is further disposed in the housing 10, the second accommodating cavity 12 is formed by the bracket 50, and at least part of the second accommodating cavity 12 is used for accommodating the battery 30; the first accommodating chamber 11 and the second accommodating chamber 12 are partitioned by the side wall 543. The second accommodating cavity 12 is arranged side by side with the first accommodating cavity 11, and is completely isolated by the side wall 543 on the bracket 50, so that air flow, generated heat and tobacco residue and tobacco tar generated in the first accommodating cavity 11 and the heating cavity 212 cannot enter the second accommodating cavity 12, and corrosion of electronic components and the battery 30 in the second accommodating cavity 12 by the tobacco tar is avoided.

Further, as shown in fig. 3, the heating body 20 includes an upper connection seat 24 and a lower connection seat 25; as shown in fig. 5, the upper connecting seat 24 abuts against the upper end wall 541; the lower connecting seat 25 is clamped on the lower end wall 542; the upper connecting seat 24 and the lower connecting seat 25 are sleeved with sealing sleeves. As shown in fig. 3 and 6, the upper connector 24 is substantially in the shape of a plunger, the upper connector 24 is sleeved on the upper end of the base pipe 21, and the end of the upper connector 24 abuts on the upper end of the heat insulation assembly 22. The upper connector 24 has a hollow inner tube with an inner diameter substantially the same as the inner diameter of the base tube 21, which is capable of receiving an aerosol-generating substrate 200 (e.g. a cigarette). In some embodiments, the aerosol-generating substrate 200 comprises a filtration section and a heating section. The length of the heat insulation component 22 is greater than that of the base tube 21, the inner tube of the upper connecting seat 24 is configured to just accommodate the filter section of the aerosol-generating substrate 200, and the heating section of the aerosol-generating substrate 200 is accommodated in the inner cavity of the base tube 21, so that the heat generated by the base tube 21 is only used for heating the heating section of the aerosol-generating substrate 200, but not the filter section of the aerosol-generating substrate 200, thereby preventing the aerosol from scalding the mouth. The silica gel sleeves are arranged at the joints between the upper connecting seat 24 and the base pipe 21 and between the upper connecting seat 24 and the heat insulation pipe 22, so that tight connection can be formed between the upper connecting seat 24 and the two parts, and heat loss to the outside through gaps of the connecting ends is further reduced.

Similarly, the lower connecting seat 25 is approximately in a plunger shape, the lower connecting seat 25 is provided with a hollow inner tube, at least part of the inner tube of the lower connecting seat 25 is basically the same as the inner diameter of the base tube 21, and can accommodate cigarettes, and the lower connecting seat 25 is sleeved at the lower end of the base tube 21. The sealing sleeves are arranged at the connection part of the lower connecting seat 25 and the lower end wall of the bracket 50 and the connection part of the lower connecting seat 25 and the heat insulation pipe 22, so that tight connection can be formed between the lower connecting seat 25 and the connecting component thereof, and heat loss to the outside through a gap of the connecting end is further reduced.

Further, the heating body 20 mainly includes a heating assembly and a supporting assembly, and the heating assembly is fixed in the inner cavity of the bracket 50 through the supporting assembly. The heating assembly has a hollow chamber in which at least a portion of the cigarette is housed. In some embodiments, the heating assembly heats the cigarettes inside the chamber in a circumferential heating manner, for example, the heating assembly may be a resistive heating tube. Alternatively, the heating assembly is heated by infrared radiation, for example, by coating an infrared radiation material on the wall of the chamber or on the substrate of the heating element inside the chamber, and heating the material to radiate far infrared radiation of the desired intensity. In some embodiments, the heating assembly heats the cigarettes inside the chamber by means of central heating. For example, the heating element may be a resistive heating body in the form of a sheet or a rod; alternatively, the heating assembly may be a combination of an induction coil and a susceptor, the induction coil being disposed outside the chamber and the susceptor being disposed inside the chamber.

The utility model will be described with reference to a heating pipe as an example, and the heating body 20 includes a heating pipe; the heating body 20 further includes a vacuum heat-insulating pipe disposed around the heating pipe.

Specifically, the heating body 20 includes a heating assembly, a temperature measuring assembly, and a heat insulation assembly 22, where, as shown in fig. 6, the heating assembly includes a base tube 21, and a heating element is disposed on an inner wall or an outer wall of the base tube 21, where the heating element may be a heating sheet with a grid shape, and the heating element may also be a heating circuit printed on the base tube, and the type of the heating element is not specifically limited in the present utility model; as shown in fig. 3, the temperature measuring assembly includes a temperature measuring element 26 disposed at the periphery of the heating assembly and a heat shrinking tube sleeved outside the temperature measuring element 26, where the temperature measuring element may be, for example, a thermocouple, and the temperature measuring element 26 may be fixed by the heat shrinking tube. As shown in fig. 3, the heat insulation assembly 22 is coated outside the heating assembly, and the heat insulation assembly 22 includes a heat insulation pipe 221 having a vacuum and an outer sleeve 222 disposed outside the heat insulation pipe 221. In the present utility model, the outer sleeve 222 is made of PEEK (polyetheretherketone) material, which has the advantages of high temperature resistance and low heat conductivity, and the PEEK material of the outer sleeve 222 is used as the outermost protective barrier to further reduce heat loss.

Further, as shown in fig. 6, the inner cavity of the base tube 21 is configured as a heating chamber 212 for receiving the aerosol-generating substrate 200, the heating chamber 212 being formed by the base tube 21 configuration, as shown in fig. 3, 4, 6 and 7, the heating chamber 212 having oppositely disposed first and second openings 28, 29; the aerosol-generating substrate 200 is inserted into the interior of the heating chamber 212 through the first opening 28; as shown in fig. 6 and 7, at least part of the second opening 29 defines an air inlet 60, and the external air flows through the air inlet 60 into the inner cavity of the base pipe 21.

Further, as shown in fig. 6 and 7, the heat-insulating sealed cavity structure of the housing further includes an air intake pipe 61 and a sealing plug 27 provided in the air intake pipe 61; the end of the aerosol-generating substrate 200 abuts against the sealing plug 27; a gap between the sealing plug 27 and the intake pipe 61 forms an intake passage that communicates with the intake port 60; the air inlet passage extends along the longitudinal direction of the shell 10, and the air inlet sectional area of the air inlet passage is kept unchanged, so that the air inflow of the shell heat-insulating sealing cavity structure is kept stable. Specifically, one end of the air intake pipe 61 is connected to one end of the lower connection seat 25 away from the heating chamber 212, and the other end of the air intake pipe 61 communicates with the outside. The aerosol-generating substrate 200 is inserted into the base tube 21 and then abuts against the sealing plug 27, and the sealing plug 27 is slit from both the left and right sides of the air inlet tube 61, thereby forming a left-side air inlet channel and a right-side air inlet channel. Both the left side intake channel and the right side intake channel extend longitudinally to the bottom of the heating chamber 212. Thus, the inner structure of the heat-insulating sealed cavity of the housing forms an air inlet channel which is completely parallel to the longitudinal direction of the housing 10, cold air is only concentrated at the bottom opening of the heating chamber 212, and heat generated by the heating body can only be diffused through the peripheral space, so that the first accommodating cavity 11 of the heating body 20 is constructed as a closed space, and heat loss can be effectively reduced.

Still further, the control module 40 is accommodated in the second accommodating chamber 12. Specifically, the control module 40 includes a first PCBA (Printed Circuit Board ) and a second PCBA, the first PCBA is provided with a micro control unit (Microcontroller Unit, MCU) and a switch assembly 41, and the first PCBA is disposed at a position close to the battery, and the battery 30 is electrically connected with the first PCBA; the second PCBA is disposed at a position close to the heating body 20, so that conductive leads of the heating assembly and the temperature measuring assembly are conveniently connected to the second PCBA, and a charging interface is disposed on the second PCBA. Wherein the MCU and the switch assembly 41 are welded on the first PCBA, and the charging interface is welded on the second PCBA. In some embodiments of the present utility model, the temperature measuring element 26 and the conductive pins at both ends of the heating element are connected to the second PCBA, so that the MCU can adjust the heating power of the heating body 20 according to the difference between the heating temperature measured by the temperature measuring element 26 in real time and the preset temperature.

Still further, in some embodiments, the switch assembly is provided with a power indicator for indicating the power of the battery; when the first PCBA and the second PCBA are far apart, the first PCBA and the second PCBA are connected through a flexible circuit board (Flexible Printed Circui, FPC soft board).

According to the shell heat-insulating sealing cavity structure provided by the embodiment of the utility model, as the first accommodating cavity for accommodating the heating body is configured as the airtight cavity, heat generated by the heating body is difficult to exchange with the outside, so that the loss of the heat generated by the heating body can be reduced, the heat utilization efficiency of the shell heat-insulating sealing cavity structure is improved, and meanwhile, the heat generated by the heating body is also convenient to accurately control.

Thus, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concepts of the present disclosure, some details known in the art are not described. How to implement the solutions disclosed herein will be fully apparent to those skilled in the art from the above description.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that the foregoing embodiments may be modified and equivalents substituted for elements thereof without departing from the scope and spirit of the disclosure. The scope of the present disclosure is defined by the appended claims.

Claims (10)

1. A housing heat insulating sealed cavity structure, comprising:

a housing;

a heating body for heating the aerosol-generating substrate;

a first accommodating cavity is arranged in the shell and is used for accommodating the heating body; the first accommodating cavity is configured to form a closed cavity so as to prevent heat generated by the heating body from diffusing to the outside of the first accommodating cavity.

2. The housing heat seal chamber structure of claim 1 further comprising a bracket housed within the housing; the first receiving cavity is formed by the bracket construction.

3. The housing heat insulating sealed chamber structure of claim 2, wherein the bracket includes an upper end wall, a lower end wall, and side walls defining the first receiving chamber; the heating body is longitudinally abutted between the upper end wall and the lower end wall along the shell; the side wall is provided with a plurality of bosses, and at least part of the outer surface of the heating body is abutted against the bosses.

4. The housing heat-insulating sealed cavity structure according to claim 3, wherein a second housing cavity is further provided in the housing, the second housing cavity being formed by the bracket structure, at least part of the second housing cavity being for housing a battery; the first receiving cavity and the second receiving cavity are separated by the side wall.

5. The housing heat seal chamber structure of claim 4 further comprising a control module disposed within the housing, the control module comprising a first PCBA and a second PCBA, the first PCBA having a micro control unit and a switch assembly disposed thereon and the first PCBA disposed proximate to the battery, the battery in electrical communication with the first PCBA; the second PCBA is arranged at a position close to the heating body, and a charging interface is arranged on the second PCBA; the switch component is provided with an electric quantity indicator lamp; the first PCBA and the second PCBA are connected through a flexible circuit board.

6. A housing heat insulating sealed cavity structure according to claim 3, wherein said heating body comprises an upper connecting seat and a lower connecting seat; the upper connecting seat is abutted against the upper end wall; the lower connecting seat is clamped on the lower end wall; the upper connecting seat and the lower connecting seat are sleeved with sealing sleeves.

7. The housing heat-insulating sealed cavity structure according to claim 1, wherein the heating body comprises a heating pipe; the heating body further comprises a vacuum heat-insulating pipe arranged around the heating pipe.

8. The housing heat-insulating sealed cavity structure according to claim 7, wherein the heating body comprises a heating assembly, a temperature measuring assembly and a heat-insulating assembly, wherein the heating assembly comprises a base pipe, and a heating element is arranged on the inner wall or the outer wall of the base pipe; the temperature measuring component comprises a temperature measuring element arranged at the periphery of the heating component and a heat shrinkage tube sleeved outside the temperature measuring element; the heat insulation assembly is coated outside the heating assembly and comprises a heat insulation pipe with vacuum and an outer sleeve arranged outside the heat insulation pipe.

9. The housing heat-insulating sealed chamber structure of claim 8, wherein the interior cavity of the base tube is configured as a heating chamber for receiving the aerosol-generating substrate, the heating chamber having oppositely disposed first and second openings; the aerosol-generating substrate is inserted into the interior of the heating chamber through the first opening; at least a portion of the second opening defines an air inlet.

10. The housing heat insulating sealed chamber structure according to claim 9, further comprising an air intake pipe and a sealing plug provided in the air intake pipe; an end of the aerosol-generating substrate abuts the sealing plug; a gap between the sealing plug and the air inlet pipe forms an air inlet channel communicated with the air inlet; the intake passage extends in a longitudinal direction of the housing, and an intake cross-sectional area of the intake passage remains unchanged.