CN117356961A

CN117356961A - Electric dust collector

Info

Publication number: CN117356961A
Application number: CN202310611037.7A
Authority: CN
Inventors: 寺边裕希; 佐藤隼人; 中川敦史; 大西裕二
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2022-07-01
Filing date: 2023-05-26
Publication date: 2024-01-09
Also published as: JP2024006427A

Abstract

Provided is an electric vacuum cleaner capable of suppressing noise. An electric vacuum cleaner according to an aspect of the present invention includes: a housing; a cylindrical motor blower housing provided in the housing; and an electric blower housed in the electric blower housing, the electric blower housing including: a main tube portion disposed around the electric blower so as to support an outer frame of the electric blower via a vibration isolation member; a suction port provided upstream of the main tube portion in a direction of an air flow generated by driving the electric blower; a discharge portion provided downstream of the main tube portion in the direction of the airflow; and a tapered tube portion provided between the main tube portion and the discharge port portion, the cross-sectional area of the discharge port being smaller than the cross-sectional area of the main tube portion, and the cross-sectional area of the tapered tube portion being smaller from an upstream side toward a downstream side in the direction of the airflow.

Description

Electric dust collector

Technical Field

The present invention relates to an electric vacuum cleaner.

Background

The electric vacuum cleaner generates suction force by driving an electric blower provided in a housing, and sucks and removes dust on a surface to be cleaned, and at this time, noise is generated from the electric blower.

JP-A8-93683 discloses an electric centrifugal fan for improving the noise cancellation effect. The electric centrifugal blower is provided with: a motor; an impeller provided on an output shaft of the motor; a housing (including a cylindrical outer frame, first and second brackets of a circular frame shape) that houses the motor and the impeller to hold the motor; guide blades provided on the outer periphery of the motor and a rectifying plate. The housing has: a suction port provided on an upstream side of a direction of an air flow generated when the motor is driven; and a discharge port provided on the downstream side of the motor. In the electric centrifugal fan, a ventilation path is formed between the casing and the impeller and between the casing and the motor.

Disclosure of Invention

In the case of the electric centrifugal fan of japanese patent application laid-open No. 8-93683, since the shaft of the motor is supported by the outer frame of the casing via the first and second brackets and the bearing, mechanical vibration of the motor (particularly vibration of the bearing) is easily transmitted to the outer frame via the first and second brackets. Therefore, when the electric centrifugal blower is provided in the housing of the electric vacuum cleaner, the motor is mechanically vibrated to vibrate the outer frame, and noise generated by the vibration is emitted from the entire housing to the outside.

An object of an aspect of the present invention is to provide an electric vacuum cleaner which is completed in consideration of the above circumstances.

An electric vacuum cleaner according to an aspect of the present invention includes: a housing; a cylindrical motor blower housing provided in the casing; and an electric blower accommodated in the electric blower housing,

the motor blower cover has: a main tube portion disposed around the electric blower so as to support an outer frame of the electric blower via a vibration isolation member; a suction port portion provided on an upstream side of the main tube portion in a direction of an air flow generated by driving the electric blower; a discharge portion provided on a downstream side of the main tube portion in a direction of the airflow; and a tapered tube portion provided between the main tube portion and the discharge port portion,

the cross-sectional area of the discharge portion is smaller than that of the main cylindrical portion, and the cross-sectional area of the tapered cylindrical portion becomes smaller from the upstream side toward the downstream side in the direction of the air flow.

The invention provides an electric dust collector capable of reducing noise of an electric blower generated in a housing.

Drawings

Fig. 1 is a perspective view of an electric vacuum cleaner according to a first embodiment of the present invention.

Fig. 2 is a partial perspective view of the cleaner body of the electric cleaner of the first embodiment, as seen from the right oblique rear.

Fig. 3 is a left side cross-sectional view of the cleaner body of the first embodiment.

Fig. 4 is an enlarged left side partial cross-sectional view of the cleaner body of the first embodiment.

Fig. 5 is a sectional view of the I-I line of fig. 3.

Fig. 6 is a sectional view taken along line II-II in fig. 3.

Fig. 7 is a sectional view taken along line III-III in fig. 3.

Fig. 8 is a sectional view of the IV-IV line of fig. 3.

Fig. 9 is a perspective view of the motor blower cover according to the first embodiment, as seen from the rear and left side.

Fig. 10 is a left side cross-sectional view of a motor blower housing of the first embodiment in which an electric blower is housed.

Fig. 11 is a cross-sectional view of the V-V line of fig. 4.

Fig. 12 is a perspective view of the first vibration isolation member of the first embodiment.

Fig. 13 is a perspective view of a downstream side cover in the motor blower cover of the first embodiment.

Fig. 14 is a perspective view of the electric blower according to the first embodiment.

Fig. 15A is a perspective view of the second vibration preventing member of the first embodiment.

Fig. 15B is a perspective view of one side cut along half of the second vibration preventing member of fig. 15A.

Fig. 16 is an explanatory view showing a fourth vibration damping member provided in the lead opening of the downstream side cover of the first embodiment.

Fig. 17 is a perspective view of the fourth vibration preventing member of fig. 16.

Fig. 18 is a left side cross-sectional view of a motor blower housing according to modification 1 of the first embodiment in which the motor blower is housed.

Fig. 19 is a schematic left side cross-sectional view of a motor blower housing according to modification 2 of the first embodiment of the motor blower.

Fig. 20 is a left side cross-sectional view of a motor blower housing of the second embodiment in which an electric blower is housed.

Fig. 21 is a left side cross-sectional view of a motor blower housing of a third embodiment of an electric blower.

Fig. 22 is a left side cross-sectional view of a motor blower housing of a fourth embodiment of the motor blower.

Fig. 23 is a left side cross-sectional view of a motor blower housing of a fifth embodiment of the motor blower.

Detailed Description

The present invention will be described in further detail below using the drawings. The following description is illustrative in all aspects and should not be construed as limiting the invention.

(first embodiment)

Fig. 1 is a perspective view of an electric vacuum cleaner according to a first embodiment of the present invention. The electric vacuum cleaner 1 according to the first embodiment shown in fig. 1 is a stick-type wireless vacuum cleaner including a cleaner body 10, a suction port body 60, and an extension pipe 90 that detachably connects the cleaner body 10 and the suction port body 60. The electric vacuum cleaner 1 can also be used as a hand-held type by directly connecting the suction port body 60 to the cleaner body 10.

Since this electric vacuum cleaner 1 has features in the cleaner body 10, the constitution of the cleaner body 10 will be described below, and the description of the suction port body 60 and the extension pipe 90 will be omitted.

As shown in fig. 1, the cleaner body 10 includes a suction device 20 and a dust collecting device 50 detachably attached to the suction device 20.

Fig. 2 is a partial perspective view of the cleaner body of the electric cleaner of the first embodiment, as seen from the right oblique rear. Fig. 3 is a left side cross-sectional view of the cleaner body of the first embodiment. For convenience of explanation of the constitution of the cleaner body 10, a direction seen from a user holding the cleaner body 10 horizontally is referred to as a front-rear, left-right, up-down direction of the cleaner body 10, and is indicated by an arrow in fig. 2, 3, and the like.

As shown in fig. 2 and 3, the suction device 20 includes a housing 21, a cylindrical motor blower cover 30 provided in the housing 21, a motor blower 40 accommodated in the motor blower cover 30, and a battery 11 detachably attached to the housing 21. The housing 21 has: an electric component housing portion 21a that houses electric components such as the motor blower cover 30 housing the motor blower 40 and the circuit board 41 constituting the control portion; a handle portion 21b connected to the rear end of the electrical component housing portion 21 a; and a suction tube portion 21c connected to a front end of the electric component housing portion 21a opposite to the rear end thereof via a connection portion 21 x.

As shown in fig. 2 and 3, the handle portion 21b has a substantially U-shape with a lateral direction having an upper end and a lower end, as viewed from the left-right direction. The cleaner body 10 further includes an operation portion 21d provided at an upper end of the handle portion 21b and a battery mounting portion 21e provided at a lower end of the electric component housing portion 21 a. The operation unit 21d is provided with a plurality of operation switches, and for example, an operation of switching from power OFF to operation in the normal mode, an operation of switching from operation in the power mode, and an operation of switching from operation in the normal mode or operation in the power mode to operation in the power OFF are possible. A plurality of power receiving terminals (not shown) are provided at the front end of the battery mounting portion 21e, and a plurality of power feeding terminals (not shown) of the battery 11 mounted on the battery mounting portion 21e are electrically connected to the plurality of power receiving terminals.

Fig. 4 is an enlarged left side partial cross-sectional view of the cleaner body of the first embodiment. Fig. 5 is a sectional view of the I-I line of fig. 3. As shown in fig. 4 and 5, the electric component housing portion 21a includes a front wall 21aa, a rear wall 21ab, left and right side walls 21ac, an upper wall 21ad, a bottom wall 21ae, a front end opening 21af provided in the front wall 21aa, and an exhaust port 21ag formed of a plurality of small holes provided in the right side wall 21 ac. The rear wall 21ab is configured to be directed rearward as going downward, so that a distance from a lower portion of the discharge port portion 32a of the motor blower cover 30 to be described later is longer than a distance from an upper portion of the discharge port portion 32 a. Thereby, the air discharged from the discharge port portion 32a easily flows downward.

Fig. 6 is a sectional view taken along line II-II in fig. 3. Fig. 7 is a sectional view taken along line III-III in fig. 3. Fig. 8 is a sectional view of the IV-IV line of fig. 3. As shown in fig. 6, 7, and 8, in the electric component housing portion 21a, the bottom wall 21ae has a flat inner bottom surface, and the left and right side walls 21a and the upper wall 21a have concave curved inner surfaces. Therefore, the lower internal space of the electric component housing portion 21a is wider than the upper internal space, and the substantially cylindrical motor blower cover 30 is housed in the upper internal space. Details of the motor blower cover 30 will be described later. In addition, most of the exhaust port 21ag is located in the lower internal space (below the axial center P of the electric blower 40) (see fig. 6).

As shown in fig. 2 and 6, the battery mounting portion 21e is a recess that opens rearward and downward on the rear side provided on the lower surface of the bottom wall 21 ae. The battery mounting portion 21e has left and right holding pieces 21ea, and the left and right holding pieces 21ea are formed by extending and sagging left and right side walls 21ac downward from the bottom wall 21 ae. Grooves 21eb extending in the front-rear direction are provided in the inner surfaces of the left and right holding pieces 21ea, respectively. On the other hand, protrusions 11a extending in the front-rear direction are provided on the left and right side surfaces of the battery 11, respectively. When the battery 11 is mounted from the rear of the battery mounting portion 21e, the left and right protrusions 11a are fitted into the left and right grooves 21eb and slide.

As shown in fig. 2 and 3, the suction tube portion 21c of the housing 21 communicates with the electric component housing portion 21a via the dust collection device 50. The suction tube portion 21c has a front end opening portion 21ca and a connection opening portion 21cb located rearward of the front end opening portion 21ca, and the front end opening portion 21ca and the connection opening portion 21cb communicate with each other. A sealing member is provided at the connection port 21 cb. In the case 21, a portion along the front end side of the electric component housing portion 21a from the lower portion side of the suction tube portion 21c becomes a dust collecting device mounting portion to which the dust collecting device 50 is detachably mounted.

Here, the dust collecting device 50 will be described. As shown in fig. 2 and 3, the dust collecting device 50 includes a dust collecting container 51 and a filter unit 52.

The dust collection container 51 has an one end opening portion detachably fitted into the filter unit 52, an openable and closable bottom cover 51a on the opposite side of the one end opening portion, and an air introduction port 51b provided in the peripheral wall of the dust collection container 51.

The filter unit 52 has: a filter portion 52a fitted into an opening portion of one end of the dust collection container 51; and a mesh-shaped inner tube portion 52b provided on the filter portion 52a so as to be disposed inside the dust collection container 51, the inner tube portion 52b and the filter portion 52a communicating with each other.

As shown in fig. 2 and 3, the dust collecting device 50 is attached to the dust collecting device attachment portion of the housing 21 in a state in which the dust collecting container 51 is directed forward and the filter unit 52 is directed rearward. At this time, the air inlet 51b of the dust collection container 51 is connected to the connection port 21cb of the suction tube 21c via a sealing member, and the locking claw 52aa provided on the outer peripheral surface of the filter portion 52a of the filter unit 52 is locked to the locking portion 21acx provided on the right side wall 21ac of the housing 21. In the attached state, the hook 51c provided on the outer peripheral surface of the peripheral wall of the dust container 51 is engaged with the engagement recess 21cc provided at the lower end of the suction tube 21c, and the filter 52a is air-tightly fitted to the fitting tube 31c of the motor blower cover 30 (see fig. 4).

< construction of Motor blower cover >

Next, the motor fan housing 30 will be described.

As shown in fig. 9 and 10, the motor blower cover 30 includes: a main tube portion 31a disposed around the electric blower 40 so as to support the outer frame of the electric blower 40 via the first vibration isolation member 34; a suction port 31b provided upstream of the main tube 31a in the direction a of the air flow generated by the electric blower 40; a discharge portion 32a provided downstream of the main tube portion 31a in the direction a of the airflow; and a tapered tube portion 32b provided between the main tube portion 31a and the discharge port portion 32 a. The electric blower 40 is disposed substantially entirely within the main tube portion 31a, and when the electric blower 40 is driven, air flows from the intake port portion 31b to the discharge port portion 32a through the electric blower 40.

In the case of the present embodiment, the electric blower 40 includes: a fan case 40b disposed on the upstream side in the direction A1 of the airflow; and a motor 40c that is provided downstream of the fan housing 40b so as to rotationally drive a fan (not shown) in the fan housing 40b, and the outer diameter of the fan housing 40b is larger than the outer diameter of the motor 40 c.

The fan housing 40b has a suction port 40a provided at the upstream end portion and a discharge port provided at the downstream end portion and located outside the motor portion 40c, and air in the fan housing 40b flows out from the discharge port and through the outside of the motor portion 40c toward the discharge port 32 a. Here, the outer frame of the electric blower 40 is a portion exposed to the outside of the electric blower 40, and does not include a shaft of the motor portion 40c and a bearing for supporting the shaft. The outer frame of the electric blower 40 includes a motor housing including a fan housing 40b and a motor portion 40c, and further includes mounting members for mounting vibration-proof members provided to the fan housing 40b and the motor housing, respectively.

More specifically, as shown in fig. 9 and 10, in the case of the present embodiment, the motor blower cover 30 includes an upstream cover 31 constituting the suction port portion 31b and the main cylinder portion 31a, and a downstream cover 32 constituting the tapered cylinder portion 32b and the discharge port portion 32a, which are separate from each other.

As shown in fig. 10, the upstream side cover 31 has an opening end 31aa on the downstream side in the direction a of the air flow of the main tube portion 31a, and the opening end 31aa has an inner diameter larger than the outer diameter of the electric blower 40. The inner diameter of the upstream side portion of the main tube portion 31a is gradually smaller than the outer diameter of the electric blower 40 as it goes to the upstream side, and a grid-like suction port 31b is provided at the upstream side end portion of the main tube portion 31a so as to face the suction port 40a of the electric blower 40. The center of the intake port 31b is offset downward from the axial center P of the electric blower 40.

As shown in fig. 4 and 10, the upstream cover 31 has a fitting tube 31c (see fig. 9), and the fitting tube 31c is hermetically fitted to the front end opening 21af of the electrical component housing 21a of the case 21 via the seal 33 so as to cover the periphery of the suction port 31 b. The seal 33 is provided on the outer peripheral surface of the fitting cylindrical portion 31 c. The fitting cylindrical portion 31c is circular when viewed from the upstream side in the air flow direction a, and the center of the fitting cylindrical portion 31c is offset downward from the center of the suction port portion 31 b. Therefore, as shown in fig. 9 and 10, a guide wall portion 31ca that guides the air to the suction port portion 31b without leaking is provided at the downstream side end portion of the fitting tube portion 31 c. Further, an upper projection 31ab is provided on the upper surface of the upstream side of the main tube portion 31a, and a lower projection 31cb is provided on the lower end of the guide wall portion 31ca, and the upper projection 31ab and the lower projection 31cb are engaged with the inner surface in the vicinity of the front end opening portion 21af of the housing 21 (see fig. 4).

Fig. 11 is a cross-sectional view of the V-V line of fig. 4. Fig. 12 is a perspective view of the first vibration isolation member 34 of the first embodiment. Such asAs shown, the first vibration isolation member 34 is a cylindrical rubber member, and is fitted into a convex curved surface portion from the outer peripheral surface 40bf of the fan housing 40b (outer frame of the electric blower 40) having the largest outer diameter of the electric blower 40 to the vicinity of the suction port 40 a. The first vibration isolation member 34 has a flange portion 34a disposed in the vicinity of the suction port 40a, and has a plurality of buffer portions 34b disposed on the outer peripheral surface 40bf of the fan housing 40 b.

As shown in fig. 10, the flange portion 34a of the first vibration preventing member 34 abuts against the annular rib 31ac provided inside the upstream end portion of the upstream side cover 31, whereby the sealability is ensured so that air between the fan case 40b and the main tube portion 31a does not flow to the suction port 40a. The annular rib 31ac is a rib protruding downstream in the direction a of the air flow around the axis P.

As shown in fig. 10, the plurality of buffer portions 34b of the first vibration preventing member 34 are provided at positions downstream of the flange portions 34a in the direction a of the air flow. Such asEach buffer portion 34b is a portion that is curved in the thickness direction so as to be convex on the outside and concave on the inside, and extends in the axial center P direction and is provided at equal intervals in the circumferential direction. The convex sides of the plurality of cushioning portions 34b abut against the inner peripheral surface 31af of the main cylindrical portion 31a of the upstream-side cover 31, and mechanical vibration of the electric blower 40 is absorbed by the cushioning portions 34b, so that it is difficult to transmit the mechanical vibration to the upstream-side cover 31. In other words, the mechanical vibration of the electric blower 40 is absorbed by the elastic deformation of the plurality of cushioning portions 34b (the elastic deformation in the direction of the convex deformation), and is hardly transmitted to the upstream side cover 31.

As shown in fig. 9 and 10, in the case of the present embodiment, the downstream side cover 32 of the motor blower cover 30 has a tapered tubular portion 32b and a discharge port portion 32a, and has an opposite opening end portion 32c on the upstream side of the tapered tubular portion 32b in the air flow direction a. The tapered tube portion 32b is formed in a substantially truncated cone shape having a tip end tapered from the opposite opening end portion 32c toward the discharge portion 32 a. The tapered tube portion 32b may be a complete truncated cone, but a projection or a recess may be provided on a part of the inner peripheral surface and the outer peripheral surface of the tapered tube portion 32 b. The tapered tube portion 32b may be of a shape in which the outlet (the outlet portion 32a side) is narrower than the inlet (the opposite opening end portion 32c side), and the inner peripheral surface of the tapered tube portion 32b may be formed in a stepped shape or may be provided with rounded irregularities. The downstream side cover 32 further includes: a connecting tube portion 32d provided between the opposite opening end portion 32c and the taper tube portion 32 b; a discharge tube portion 32e provided between the tapered tube portion 32b and the discharge port portion 32 a; and a rectifying portion 32f provided at a position ranging from the downstream end portion of the airflow direction a of the tapered tube portion 32b to the discharge port portion 32a, for rectifying the airflow. In fig. 10, it is seen that the peripheral edge portion of the lattice of the rectifying portion 32f, which is in contact with the inner surface of the tapered tube portion 32b, protrudes beyond the inner surface of the tapered tube portion 32b and has a step, but as shown in fig. 6 or 9, there is actually no step. Therefore, the air flow along the inner surface of the tapered tube portion 32b is not hindered by the step.

As shown in fig. 9 and 10, in the downstream-side cover 32, the longitudinal cross-sectional shape of the tapered tube portion 32b along the axis P is substantially a truncated cone shape, and the cross-sectional area of the cross-section in the direction orthogonal to the axis P decreases from the upstream side toward the downstream side in the direction a of the air flow. In the downstream-side cover 32, the cross-sectional area of the discharge port portion 32a is smaller than the cross-sectional area of the main tube portion 31a of the upstream-side cover 31, the cross-sectional area of the connecting tube portion 32d is equal to the cross-sectional area of the opposite opening end portion 32c, and the cross-sectional area of the discharge tube portion 32e is equal to the cross-sectional area of the discharge port portion 32 a.

Fig. 13 is a perspective view of a downstream side cover in the motor blower cover of the first embodiment. As shown in fig. 10 and 13, the tapered tube portion 32b has a tapered inner peripheral surface that tapers toward the front end in the direction A2 of the airflow (from the upstream side to the downstream side), and a plurality of (in this case, 3) mounting stepped portions 32ba are provided at equal intervals in the circumferential direction on the inner peripheral surface. In the present embodiment, the inner peripheral surface is linear cone-shaped, but may be parabolic cone, exponential cone, or a combination thereof. The plurality of mounting step portions 32ba each have a flat surface 32bx facing the axial center P direction, and surrounding ribs 32by surrounding the flat surface 32bx so as to open in a direction orthogonal to the axial center P direction and the axial center P. The plurality of mounting stepped portions 32ba are recessed scaffolds for fitting the downstream side cover 32 into the downstream side end portion of the electric blower 40 via the second vibration preventing member 35.

Fig. 14 is a perspective view of the electric blower according to the first embodiment. As shown in fig. 14, the electric blower 40 includes a fan housing 40b and a motor portion 40c provided downstream of the fan housing 40b in the direction a of the airflow. A circuit board 40e for driving the motor is provided at the downstream end of the motor portion 40c (motor case) of the electric blower 40 via a plurality of (3 in this case) mounting pins 40 d. In this case, the plurality of mounting legs 40d extend from the vicinity of the rear end of the fan housing 40b, and form an outer frame of the electric blower 40. As shown in fig. 4 and 8, the circuit board 40e faces the direction A1 of the airflow, and the downstream side surface 40ef of the circuit board 40e faces the discharge port portion 32a, and when the contour R of the discharge port portion 32a is projected onto the downstream side surface 40ef of the circuit board 40e, the contour R of the discharge port portion 32a is received in the downstream side surface 40 ef. The air flow from the electric blower 40 passes through the outside of the circuit substrate 40e.

The plurality of mounting legs 40d have a substantially U-shaped cross-sectional shape, are provided at equal intervals in the circumferential direction on the outer peripheral portion of the downstream side end portion of the motor portion 40c, and extend substantially parallel to the axis P on the downstream side of the motor portion 40c. A plurality of (in this case, 3) cutouts 40ea are provided at equal intervals on the outer peripheral edge of the circuit board 40e, and the plurality of mounting pins 40d are fitted into the plurality of cutouts 40ea. The downstream end portions of the plurality of mounting pins 40d are disposed downstream of the circuit board 40e in the air flow direction a. Further, a pair of leads 40f electrically connected to the motor portion 40c extend downstream through holes formed in the circuit board 40e.

Fig. 15A is a perspective view of the second vibration preventing member 35 of the first embodiment. Fig. 15B is a perspective view of one side cut along half of the second vibration preventing member of fig. 15A. The second vibration isolation member 35 is made of rubber, and includes: a recess 35a fitted into the downstream side end portion (see fig. 14) of the mounting leg 40d, and a plurality of (4 in this case) buffer portions 35b around the recess 35 a. The plurality of buffer portions 35b are formed by swelling a plurality of portions of the outer surface of the second vibration isolation member 35 to form a plurality of convex portions, and are formed by forming holes or recesses in the inner surface side of the plurality of convex portions.

As shown in fig. 9 and 13, a pair of attachment projections 32bb projecting in a direction orthogonal to the axis P are provided on the outer peripheral surface of the tapered tube portion 32b of the downstream-side cover 32 at a position at a center angle of 180 °. A third vibration preventing member 35x having the same configuration as the second vibration preventing member 35 described in fig. 15A and 15B is attached to the pair of attachment protrusions 32 bb. On the other hand, fitting ribs 21acy are provided on inner surfaces of left and right side walls 21ac of the electric component housing portion 21a of the casing 21, and the fitting ribs 21acy receive a pair of third vibration-proof members 35x (see fig. 5) so as to support the downstream side cover 32 via the pair of third vibration-proof members 35x.

A plurality of (3 in this case) receiving pieces 32da (see fig. 10) having an L-shaped longitudinal section are provided on the outer peripheral surface of the connecting tube portion 32d at equal intervals in the circumferential direction, and a plurality of (3 in this case) locking projections 32db are provided at positions between two adjacent receiving pieces 32da. Since the downstream side cover 32 has the connecting tube portion 32d between the opposite opening end portion 32c and the tapered tube portion 32b, and the connecting tube portion 32d has the same cross-sectional area as the opposite opening end portion 32c, the support piece 32da for supporting the opening end portion 31aa can be provided on the outer peripheral surface of the connecting tube portion 32d in a state where the sealing vibration-proof member 36 is sandwiched between the opening end portion 31aa of the upstream side cover 31 and the opposite opening end portion 32c of the downstream side cover 32. As shown in fig. 13, a single slit-shaped lead opening 32ca is provided from the opposite opening end portion 32c to the tapered tube portion 32b, and a sealing vibration-proof member 36 is provided along the edge of the opposite opening end portion 32c (see fig. 10). However, a sealing portion 37c (see fig. 17) is disposed at a position opposite to the lead opening 32ca in the opening end portion 32c, and the sealing portion 37c is provided as a part of a fourth vibration isolation member 37 to be described later in place of the sealing vibration isolation member 36. The sealing vibration isolation member 36 is made of a material having both vibration isolation and sealing properties, and is formed of a molded product made of rubber in the present embodiment. The sealing vibration damping member 36 may be a sealing tape, and in this case, the sealing tape may be stacked in a plurality of layers so as to have a thickness such that both vibration damping property and sealing property are obtained.

On the other hand, as shown in fig. 9 and 10, the opening end 31aa of the upstream side cover 31 is slightly larger than the diameter of the main tube 31a, and the opposite opening end 32c of the downstream side cover 32 is accommodated via the sealing vibration-proof member 36 and the sealing portion 37 c. Further, a plurality of locking pieces 31ax, which are locked with the plurality of locking projections 32db of the downstream side cover 32, are provided on the outer peripheral surface of the opening end portion 31aa of the upstream side cover 31. Each locking piece 31ax is formed with a locking hole 31ay which can be attached to and detached from each locking protrusion 32 db. At the time of locking, each locking piece 31ax slides so as to raise the inclined surface of each locking protrusion 32 db. When the locking pieces 31ax are lifted, the locking holes 31ay are disengaged from the locking projections 32 db.

Fig. 16 is an explanatory view showing a fourth vibration damping member 37 provided in the lead opening of the downstream-side cover of the first embodiment. Fig. 17 is a perspective view of the fourth vibration preventing member 37 of fig. 16. As shown in fig. 16 and 17, the fourth vibration isolation member 37 is formed of a rubber-made tip having a shape that can be fitted into the lead opening 32ca (see fig. 13) of the downstream side cover 32, and has a cutout for opening in a substantially V-shape or a substantially U-shape. As shown in fig. 17, a plurality of pairs of grooves 37a for inserting lead wires are formed at the positions of the cutouts of the fourth vibration damping member 37, and an outer peripheral groove 37b is formed along the outer peripheral surface. A pair of sealing portions 37c protrude from outer peripheral grooves 37b at both ends of the third vibration preventing member 37.

The fourth vibration isolation member 37 shown in fig. 17 is attached by fitting the outer peripheral groove 37b into the edge of the lead opening 32ca of the downstream side cover 32 shown in fig. 13 (see fig. 16). A pair of leads 40f from the electric blower 40 shown in fig. 14 pass through the cutouts (see fig. 16 and 17) of the fourth vibration damping member 37 attached to the lead opening 32ca, and are held and fixed at the positions of the respective pairs of grooves 37 a. The fourth vibration preventing member 37 eliminates the gap of the cutout portion by fitting into the lead opening 32ca, and the hole formed by each pair of grooves 37a is also blocked by the pair of leads 40 f.

As shown in fig. 10, the rectifying portion 32f of the downstream side cover 32 is not particularly limited in shape and configuration as long as it can obtain a rectifying effect on the air flow from the tapered tube portion 32b toward the discharge portion 32 a. In the present embodiment, the rectifying portion 32f is formed in a lattice shape having a predetermined thickness in the axial center P direction (see fig. 6), and is provided at the boundary between the downstream end portion of the tapered tube portion 32b in the air flow direction a and the discharge tube portion 32 e. The boundary is an intermediate position Q in the axial center P direction of the curved portion where the downstream side end of the tapered tube portion 32b is connected to the discharge tube portion 32 e. More specifically, in the case of the present embodiment, the downstream end of the tapered tube portion 32b includes, from the intermediate position Q toward the upstream side in the direction a of the airflow The upstream end of the discharge tube portion 32e includes +.>Left and right ranges. The rectifying portion 32f has a thickness (for example(left and right)) The rectifying portion 32f is disposed at the intermediate position Q in the middle in the thickness direction. If a part of the rectifying portion 32f is disposed at the intermediate position Q, the rectifying portion 32f may be disposed at a position deviated to the upstream side or the downstream side. As shown in fig. 6, in the case of the present embodiment, the rectifying portion 32f has a lattice shape (substantially spider-web shape) in which a plurality of radial beams are provided between a plurality of concentric circles, and the position of the inner beam is deviated from the position of the outer beam. In the present embodiment, the upstream end of the lattice is a flat surface, but may have a circular shape such as a semicircular shape or a streamline shape.

Referring to fig. 10, a description will be given of a procedure when the electric blower 40 having the first vibration isolation member 34 and the second vibration isolation member 35 attached thereto is housed in the electric blower housing 30. First, the electric blower 40 is inserted into the opening end 31aa of the upstream cover 31 from the suction port 40a side. At this time, when the electric blower 40 is inserted into the stepped portion 31ag provided on the inner surface of the main tube portion 31a of the upstream side cover 31 until the first vibration preventing member 34 abuts, the flange portion 34a of the first vibration preventing member 34 abuts the annular rib 31ac in the main tube portion 31 a.

After that, the opposite opening end portion 32c of the downstream side cover 32 to which the sealing vibration preventing member 36 and the fourth vibration preventing member 37 are attached is fitted into the opening end portion 31aa of the upstream side cover 31. At this time, a pair of leads 40f (see fig. 14) of the electric blower 40 are passed through the cutout (see fig. 16) of the fourth vibration prevention member 37 in advance. When the upstream side cover 31 and the downstream side cover 32 are connected, the plurality of second vibration preventing members 35 attached to the plurality of mounting legs 40d of the electric blower 40 are aligned so as to fit into the plurality of mounting stepped portions 32ba of the downstream side cover 32, and the downstream side cover 32 is fitted into the upstream side cover 31. Thus, the motor blower 40 is supported in the motor blower case 30 so that the axial center P passes through the substantial center of the discharge tube portion 32e and the discharge outlet portion 32a of the motor blower case 30. By fitting the downstream cover 32 into the upstream cover 31, the locking holes 31ay of the locking pieces 31ax of the upstream cover 31 are locked to the locking projections 32db of the downstream cover 32 (see fig. 16), and the sealing vibration isolating member 36 of the downstream cover 32 and the sealing portion 37c of the fourth vibration isolating member 37 are brought into close contact with the stepped portion 31ak (see fig. 10) provided on the inner surface of the opening end portion 31aa of the upstream cover 31.

Description of the operation of the cleaner body

As shown in fig. 3, when the operation portion 21d of the suction device 20 is operated to drive the electric blower 40, the inside of the electric blower housing 30 is negative pressure, and dust-containing air flows into the front end opening portion 21ca of the suction tube portion 21c, and the dust-containing air flows into the dust collection container 51 through the air inlet 51b of the dust collection container 51 of the dust collection device 50 from the connection portion 21cb of the suction tube portion 21 c. The air containing dust swirls in the dust collection container 51, and the first relatively large dust is centrifugally separated from the air in the dust collection container 51, and the second dust smaller than the first dust is captured by the filter portion 52a through the mesh-shaped inner tube portion 52 b.

As shown in fig. 4 and 10, the air from which the second dust is removed by the filter portion 52a flows from the fitting cylindrical portion 31c of the motor blower cover 30 to the suction port 40a of the motor blower 40 through the suction port portion 31 b. The air flowing into the suction port 40a passes through the fan housing 40b, passes through the flow path between the motor portion 40c and the inner peripheral surface of the main tube portion 31a in the arrow Al direction, passes through the tapered tube portion 32b, the rectifying portion 32f, and the discharge tube portion 32e, reaches the discharge port portion 32a, and is discharged from the discharge port portion 32a toward the rear wall 21ab of the housing 21. The air discharged from the discharge port portion 32a collides with the rear wall 21ab, is folded back, and is discharged to the outside from the discharge port 21ag of the right side wall 21ac (see fig. 2) of the casing 21. In this way, the exhaust path from the exhaust port portion 32a to the exhaust port 21ag can be extended by turning back, and thus noise generated from the electric blower 40 can be suppressed.

In general, noise of the cleaner body includes noise (mechanical noise) generated by vibration of the electric blower, wind noise (ventilation noise) generated by air flowing in the housing, and high frequency sound (electromagnetic noise) from a motor of the electric blower. As shown in fig. 4 and 10, noise generated by driving the electric blower 40 in the electric blower housing 30 and released to the outside of the cleaner body 10 is suppressed as follows.

As shown in fig. 4 and 10, according to the motor blower cover 30 of the present embodiment, the vibration of the motor blower 40 is absorbed and attenuated by the first vibration damping member 34 and the plurality of second vibration damping members 35, and therefore the rattling sound of the joint portion of the motor blower 40 and the motor blower cover 30 is suppressed (suppression of mechanical noise). In other words, the mechanical vibration of the motor blower 40 is difficult to be transmitted to the motor blower cover 30. In addition, vibration (resonance) of the pair of leads 40f (see fig. 16) is suppressed (suppression of mechanical noise) by the fourth vibration damping member 37 provided in the lead opening 32ca (see fig. 13) of the downstream side cover 32 of the motor blower cover 30. In addition, the motor blower cover 30 can be easily manufactured by using a plurality of members of the upstream side cover 31 and the downstream side cover 32, and resonance of the upstream side cover 31 and the downstream side cover 32 can be suppressed by the sealing vibration-proof member 36, so that the noise reduction of the electric vacuum cleaner 1 can be facilitated. The air flowing through the motor blower cover 30 is also turbulent when passing through the tapered tube portion 32b, is rectified by the rectifying portion 32f, and is stably rectified while passing through the discharge tube portion 32e, and is discharged from the discharge port portion 32a into the housing 21, whereby wind noise can be suppressed to be small (ventilation noise can be suppressed).

In addition, the high-frequency sound reflection cross-sectional area from the motor portion 40c of the electric blower 40 is attenuated (electromagnetic noise is suppressed) while being reduced toward the downstream side in the air flow direction a of the tapered inner surface of the tapered tube portion 32 b. As shown in fig. 4 and 8, the circuit board 40e has a size such that the contour R of the discharge port portion 32a is received in the downstream-side surface 40ef when the contour R of the discharge port portion 32a is projected onto the downstream-side surface 40ef of the circuit board 40 e. That is, the circuit board 40e serves as an obstacle so that the high-frequency sound from the motor 40c does not directly travel straight toward the discharge port 32 a. This configuration also contributes to suppression of electromagnetic noise.

Such various noises are suppressed by covering the entire electric blower 40 with the electric blower cover 30.

As described above, according to the present embodiment, the electric vacuum cleaner can be silenced. Further, as shown in fig. 10, according to the motor blower cover 30 of the present embodiment, since the air flow from the motor blower 40 toward the discharge portion 32a flows along the axial center P of the motor blower 40, the exhaust pressure loss is suppressed to be small, and the intake power efficiency is maintained.

Modification 1 of the first embodiment

Fig. 18 is a left side cross-sectional view of a motor blower housing according to modification 1 of the first embodiment in which the motor blower is housed. In fig. 18, elements identical to those in fig. 10 are given the same reference numerals.

As shown in fig. 18, in the case of the motor blower cover 130 of modification 1, by providing the shielding plate portion 131ba below the suction port portion 131b of the upstream side cover 131, the area of the suction port portion 131b is reduced as compared with the case of the first embodiment, and the entire suction port portion 131b is opposed to the suction port 40a of the motor blower 40. With this configuration, the high-frequency sound of the electric fan 40 is less likely to be released from the intake port 131b into the casing while maintaining the intake power, and the noise suppressing effect can be improved.

Modification 2 of the first embodiment

Fig. 19 is a schematic left side cross-sectional view of a motor blower housing according to modification 2 of the first embodiment of the motor blower. In fig. 19, elements identical to those in fig. 10 are given the same reference numerals.

As shown in fig. 19, the motor blower case 230 according to modification 2 is provided with a sound absorbing material in the motor blower case 130 according to modification 1. In fig. 19, the fitting cylindrical portion 31c (see fig. 18) of the upstream cover 131 of the motor blower cover 230 is omitted.

To describe in detail modification 2, a sheet-like first sound absorbing member 38 is attached to the inner surface of the tapered tube portion 32b of the downstream side cover 32 of the motor blower cover 230. A second sound absorbing member 39 having a bottomed tubular shape is attached to the outer peripheral surface of the discharge tube portion 32e so as to cover the discharge outlet portion 32a of the downstream side cover 32. The first and second sound absorbing members 38, 39 are each formed of a porous sheet member, and the mesh of the second sound absorbing member 39 is thicker than the mesh of the first sound absorbing member 38 to the extent that air can circulate. According to this configuration, in addition to the high-frequency sound being attenuated when passing through the tapered tube portion 32b, the attenuated high-frequency sound emitted from the discharge port portion 32a can be attenuated by the second sound absorbing member 39. In addition, any one of the first and second sound absorbing members 38, 39 may be omitted. The first sound absorbing material 38 or the second sound absorbing material 39 may be applied to the motor blower cover 30 of the first embodiment (see fig. 10).

(second embodiment)

Fig. 20 is a schematic left side cross-sectional view of a motor blower housing of a second embodiment of an electric blower. In fig. 20, elements identical to those in fig. 10 and 19 are given the same reference numerals.

As shown in fig. 20, a motor blower cover 330 according to the second embodiment is substantially the same as the motor blower cover 230 according to modification 2 of the first embodiment except for the configuration. The following mainly describes differences between the second embodiment and modification 2 of the first embodiment.

In the case of the motor blower cover 330 of the second embodiment, the connection tube portion 32d is omitted from the downstream side cover 332 (see fig. 19). The main tube portion 131a of the upstream-side cover 331 extends to the tapered tube portion 32b of the downstream-side cover 332, and the opening end portion 131aa provided at the downstream-side end portion of the main tube portion 131a in the direction a of the air flow and the opposite opening end portion 332c provided at the upstream-side end portion of the tapered tube portion 32b are fitted to each other via a sealing member (not shown). In this way, the downstream cover 332 may be configured to omit the connecting tube portion. In the motor blower cover 30 (see fig. 10) according to the first embodiment, the connection tube portion 32d may be omitted.

(third embodiment)

Fig. 21 is a schematic left side cross-sectional view of a motor blower housing of a third embodiment of an electric blower. In fig. 21, elements identical to those in fig. 10 and 20 are given the same reference numerals.

As shown in fig. 21, the motor blower cover 430 of the third embodiment is substantially the same as the motor blower cover 330 of the second embodiment except for the configuration. Hereinafter, the differences from the second embodiment in the third embodiment will be mainly described.

In the case of the motor blower cover 430 of the third embodiment, the discharge cylinder portion 432e of the downstream side cover 432 includes: an upstream constant diameter portion 432ea connected to a downstream end of the tapered tube portion 32b in the direction a of the air flow; an expanded diameter portion 432eb connected to a downstream end of the upstream constant diameter portion 432ea and expanding toward the downstream; and a downstream constant diameter portion 432ec connecting a downstream end of the expanded diameter portion 432eb and the discharge port portion 432 a. In this case, when the contour R of the discharge port portion 432a is projected onto the downstream side surface 40ef of the circuit board 40e of the electric blower 40 as viewed from the discharge port portion 432a side, the contour R is received in the downstream side surface 40 ef. In this way, the discharge tube portion 432e of the downstream side cover 332 may be slightly wider toward the downstream side. In the case of the motor blower cover 430 according to the third embodiment, the inner diameter of the outlet portion 432a is larger than the upstream constant diameter portion 432ea, but when the contour R of the outlet portion 432a is projected onto the downstream surface 40ef of the circuit board 40e, the contour R of the outlet portion 432a is received in the downstream surface 40 ef. The configuration of the discharge cylinder 432e according to the present embodiment may be applied to the motor blower cover 30 according to the first embodiment (see fig. 10).

(fourth embodiment)

Fig. 22 is a schematic left side cross-sectional view of a motor blower housing of a fourth embodiment of an electric blower. In fig. 22, elements identical to those in fig. 10 and 19 are given the same reference numerals.

As shown in fig. 22, a motor blower cover 530 according to the fourth embodiment is substantially the same as the motor blower cover 230 according to modification 2 of the first embodiment except for the configuration. The following mainly describes differences from modification 2 of the first embodiment in the fourth embodiment.

In the case of the motor blower cover 530 according to the fourth embodiment, the rectifying portion 532f of the downstream side cover 532 has a fin shape. In this case, the rectifying portion 532f formed of a plurality of fins extending in the direction a of the air flow is provided so as to be substantially equally spaced from the inner peripheral surface of the discharge tube portion 32 e. In this way, the configuration of the rectifying portion 532f can be changed. The structure of the rectifying portion 532f formed of fins according to the present embodiment may be applied to the motor blower cover 30 of the first embodiment, or the rectifying portion 32f formed of fins may be combined on the upstream side with the rectifying portion 532f formed of fins on the downstream side.

Fifth embodiment

Fig. 23 is a schematic left side cross-sectional view of a motor blower housing of a fifth embodiment of the motor blower. In fig. 23, elements identical to those in fig. 10 and 20 are given the same reference numerals.

As shown in fig. 23, a motor blower cover 630 of the fifth embodiment is substantially the same as the motor blower cover 330 of the second embodiment except for the configuration. Hereinafter, differences from the second embodiment will be mainly described.

In the case of the motor blower cover 630 according to the fifth embodiment, the discharge tube portion 32e (see fig. 20) of the downstream side cover 632 is omitted, and the downstream side end portion in the direction a of the airflow of the tapered tube portion 32b becomes the discharge port portion 632a. Although not shown in fig. 23, a grid-like rectifying portion may be provided in the discharge port portion 632a (see fig. 10). In this way, the downstream cover 332 may be configured to omit the discharge tube portion. In the motor blower cover 30 (see fig. 10) according to the first embodiment, the discharge tube portion 32e may be omitted.

Sixth embodiment

The motor blower covers of the first embodiment and modifications 1 and 2 and the second to fifth embodiments are made of resin, and at least one of the upstream side cover and the downstream side cover may be made of metal (for example, aluminum) or may be coated with metal (for example, plating). According to this configuration, a higher sound-insulating effect can be obtained than in the case where the motor blower cover is made of resin.

(seventh embodiment)

In the motor blower cover according to the first embodiment and modifications 1 and 2 and the second to sixth embodiments, the upstream cover may have a lead opening through which a lead of the motor blower passes and a vibration-proof member provided in the lead opening (see fig. 16). In this case, the opening end of the downstream side end of the upstream side cover is provided with a lead opening.

< other embodiments >

1. In the motor blower cover according to the above embodiment (including the modification), the motor blower cover is constituted by two members, that is, the upstream side cover and the downstream side cover, but the motor blower cover may be constituted by one member.

2. The motor blower cover according to the above embodiment (including the modification) can be applied to a suction canister type or a vertical type electric vacuum cleaner, in addition to a stick type electric vacuum cleaner.

A preferred embodiment of the present invention further includes a combination of any of the above-described embodiments.

In addition to the above embodiments, various modifications are possible to the present invention. These modifications should be construed as falling within the scope of the present invention. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Examples (example)

In order to examine the quietness of the motor blower cover (see fig. 10) of the first embodiment, in addition to the difference in the position of the rectifying portion in the axial center P direction, the motor blowers 40 were housed in the respective 3 motor blower covers (samples 1 to 3) having the same configuration and the motor blower cover (sample 4) having no rectifying portion, and the noise when the motor blowers 40 of each sample 1 to 4 were driven was measured.

Sample 1: the lattice-shaped rectifying portion 32f having a thickness of 5.5mm in the axial direction P is disposed so that the thickness center position of the rectifying portion 32f is disposed 8.5mm upstream of the intermediate position Q between the tapered tube portion 32b and the discharge tube portion 32e of the downstream side cover 32. Sample 2 (motor blower cover of the first embodiment): the lattice-shaped rectifying portion 32f having a thickness of 5.5mm in the axial center P direction is disposed so that the rectifying portion 32f is disposed at the thickness center position at the intermediate position Q.

Sample 3: the lattice-shaped rectifying portion 32f having a thickness of 5.5mm in the axial direction P is disposed so that the thickness center position of the rectifying portion 32f is disposed 13.75mm downstream of the intermediate position Q. The length in the axial direction P from the intermediate position Q to the opposite opening end 32c was 44mm, and the length in the axial direction P from the intermediate position Q to the end of the discharge port 32a was 16.5mm.

Vibration-proof sheets (square 1000mm square, thickness 60mm, about 21 kg/m) ³ Polyurethane foam) was laid on the floor, and each of samples 1 to 4 was placed on a vibration-proof sheet in order, and noise was measured. At this time, a first microphone provided on the ground surface for receiving sound toward the outlet portion 32a of the motor blower cover 40 and a second microphone suspended above the motor blower cover 40 are used. The distances from the first and second microphones to the motorized blower 40 within the motorized blower enclosure 30 are about 1500mm, respectively. Noise meters (LA-4440) using a small field detector are used for both the first and second microphones. The air volume of the electric blower 40 was set to 0.409m ³ The measurement was performed at room temperature of about 20℃and in a measurement environment of about 21dB of dark noise. The measurement results are shown in table 1.

TABLE 1

Sound pressure level [ dB ]]	First microphone	Second microphone	Average of
				Sample 1	69.39	67.25	68.32
Sample 2	69.08	66.4	67.74
				Sample 3	69.92	67.4	68.66
Sample 4	70.27	67.58	68.93

As can be seen from the results in table 1, the noise of the rectifying portions (samples 1 to 3) is smaller than that of the rectifying portion (sample 4). It is further understood that the noise of sample 2 among samples 1 to 3 is minimized, and samples 1 and 3 are successively smaller.

Claims

1. An electric vacuum cleaner is provided with: a housing; a cylindrical motor blower housing provided in the casing; and an electric blower housed in the motor blower housing, characterized in that,

The motor blower cover has: a main tube portion disposed around the electric blower so as to support an outer frame of the electric blower via a vibration isolation member; a suction port portion provided upstream of the main tube portion in a direction of an air flow generated by driving the electric blower; a discharge portion provided on a downstream side of the main tube portion in a direction of the airflow; and a tapered tube portion provided between the main tube portion and the discharge port portion,

2. The electric vacuum cleaner of claim 1, wherein the motor-blower housing includes: an upstream cover that constitutes the suction port and the main tube; and a downstream cover that constitutes the tapered tube portion and the discharge port portion,

the upstream side cover has an open end portion on a downstream side of the main tube portion in the direction of the air flow,

the downstream side cover has an opposite opening end connected to the opening end on an upstream side of the direction of the air flow of the taper cylinder portion,

The open end and the opposite open end are connected by a sealing vibration-proof member.

3. The electric vacuum cleaner according to claim 2, wherein the downstream-side cover has a connecting cylinder portion between the opposite opening end portion and the tapered cylinder portion, the connecting cylinder portion having a cross-sectional area equal to a cross-sectional area of the opposite opening end portion.

4. A vacuum cleaner according to any one of claims 1 to 3, wherein the downstream side cover has a discharge cylinder portion between the taper cylinder portion and the discharge port portion.

5. The vacuum cleaner of claim 4, wherein the discharge barrel portion has a cross-sectional area equal to a cross-sectional area of the discharge port.

6. The electric vacuum cleaner according to claim 4, wherein the downstream side cover has a rectifying portion that rectifies the air flow in a range from a downstream side end portion of the air flow direction of the taper cylinder portion to the discharge port portion.

7. The electric vacuum cleaner according to claim 6, wherein the rectifying portion is provided at a position including a boundary between the tapered cylinder portion and the discharge cylinder portion in a range from the downstream side end portion of the tapered cylinder portion to an upstream side end portion of the discharge cylinder portion in a direction of the airflow.

8. The electric vacuum cleaner of claim 6, wherein the rectifying portion is formed in a lattice shape or a fin shape.

9. A vacuum cleaner according to any one of claims 1 to 3, wherein the downstream-side cover has a sound absorbing material on an inner surface of the tapered tube portion.

10. A vacuum cleaner according to claim 2 or 3, wherein at least one of the upstream side cover and the downstream side cover is made of metal or covered with metal.

11. A vacuum cleaner according to claim 2 or 3, wherein the upstream side cover or the downstream side cover has a wire opening through which a wire of the electric blower passes and a vibration preventing member provided on the wire opening.

12. The vacuum cleaner according to any one of claims 1 to 3, further comprising a base plate provided at a downstream end portion of the electric blower in the direction of the airflow,

the substrate faces in the direction of the air flow, and a face of the downstream side of the substrate is opposed to the discharge port portion,

when the contour of the outlet portion is projected onto the downstream side surface of the substrate, the contour is received in the downstream side surface.