Patent Description:
In general, robots have been developed for industrial use and have been part of factory automation. In recent years, the field of applications of robots has been expanded, and home robots that can be used in ordinary homes as well as aerospace robots and medical robots have been made.

A representative example of a home robot may be a robot cleaner. The robot cleaner carries out a function of cleaning a floor while traveling on a predetermined area by itself. To do this, the robot cleaner includes a cleaner main body including a driving wheel for autonomous traveling, and a cleaning module for sucking dirt and foreign substances from a floor or mopping a floor.

In general, since the cleaning module is mounted on the cleaner body and located at a fixed position, a cleaning area of the cleaning module may be limited by a shape of the cleaner main body.

As an example, when a suction portion is provided on a lower surface of the robot cleaner having a cylindrical shape, there is such a limit that it is difficult to clean portions of the cleaning area. To resolve this, the <CIT>) discloses such a robot cleaner that a suction portion may move from left to right. Accordingly, the suction portion may move toward the corner portions to clean the corner areas.

As another example, when a cleaner main body is provided with a dust collecting device with large volume, the cleaner main body may have a height greater than that of a cleaning module. Since the cleaner main body cannot enter an area with a height less than that of the cleaner main body (e.g., below a sofa, a bed, a table, etc.), even when the cleaner module has a height enough to enter the area, there is such a limit that cleaning may not be performed in the area. <CIT> discloses a robot cleaner to extend a suction port from a cleaner body. <CIT> discloses a robot cleaner to improve cleaning efficiency by selectively moving a suction port to the inside or outside of a cleaner body.

An aspect of the present disclosure is to provide a robot cleaner capable of cleaning an area with a height less than that of a cleaner main body, e.g., below a sofa, a bed, a table, etc..

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a robot cleaner as defined in the independent claim <NUM>.

According to one embodiment of the present invention, the robot cleaner includes:
a cleaner main body equipped with a dust collecting device; a cleaning module that is relatively movable with respect to the cleaner main body and sucks air containing dust and foreign substances; and a connection unit that is connected to the cleaner main body and the cleaning module respectively and has a variable length, wherein the connection unit forms a part of an intake flow path that guides the air sucked by the cleaning module to the dust collecting device.

The cleaning module is relatively movable with respect to the cleaner main body between a first state when a part of the cleaning module overlaps the cleaner main body and a second state when the cleaning module protrudes towards a front of the cleaner main body.

The connection unit includes:
an outer case mounted on the cleaner main body; an inner case that is inserted into the outer case and relatively movable with respect to the outer case; and a flexible tube which is fixed to the outer case and the inner case respectively, and of which at least a part is provided to extend or contract according to the relative movement of the inner case.

The flexible tube includes a corrugated portion including a ductile material and provided to extend or contract according to the relative movement of the inner case.

The connection unit may further include a flow path connector that is connected to the cleaning module and the inner case respectively, and supplies the air sucked by the cleaning module to the inner case.

One end portion of the flexible tube may be connected to the inner case and the flow path connector.

A guide groove may be provided to extend along a longitudinal direction in the outer case, and a guide rail may be provided to protrude from the inner case, the guide rail being inserted into the guide groove and guiding the relative movement of the inner case with respect to the outer case.

The robot cleaner may further include a driving unit that relatively moves the inner case with respect to the outer case.

The driving unit may include: a driving motor including a worm mounted on a rotating shaft; a double gear in which a worm wheel engaged with the worm is combined with a pinion; and a rack gear provided on the guide rail extending along a longitudinal direction of the inner case and engaged with the pinion.

A driving motor mounting portion that fixes the driving motor and the double gear may be provided on an end portion of the outer case.

A hole connecting with inside of the outer case may be provided on an outer circumference of the outer case, and the flexible tube may further include a bending portion extending from the corrugated portion and penetrating the hole.

The dust collecting device may be disposed on the outer case, and the bending portion may extend upward toward the dust collecting device.

A support portion surrounding a front of the hole may be provided to protrude from the outer case, and thus support a front of the bending unit when the inner case relatively moves with respect to the outer case.

A cutout portion may be provided in the inner case along a longitudinal direction to prevent interference with the bending portion when the inner case relatively moves with respect to the outer case.

The cleaning module may be provided to be relatively movable between a first state when a part of the cleaning module overlaps the cleaner main body and a second state when the cleaning module protrudes towards a front of the cleaner main body, and the inner case may be completely accommodated in the outer case in the first state.

According to another one embodiment of the present invention, a robot cleaner may include: a cleaner main body equipped with a dust collecting device; a cleaning module that is relatively movable with respect to the cleaner main body and cleans a floor; an outer case mounted on the cleaner main body; an inner case inserted into the outer case and provided to be relatively movable with respect to the outer case; a connector connected to the cleaning module and the inner case respectively; and a driving unit that relatively moves the inner case with respect to the outer case.

A driving motor mounting portion that fixes the driving motor may be provided in a front end portion of the outer case.

According to the present invention, since a cleaning module is configured to protrude from a cleaner main body according to extension of a length of a connection unit, the cleaning module may enter an area of which height is less than that of the cleaner main body, for example, below a sofa, a bed, a table, or the like. As a result, a cleaning area of the robot cleaner may be enlarged.

Hereinafter, a robot cleaner according to the present invention will be described in detail with reference to the accompanying drawings.

<FIG> is a perspective view illustrating one example of a cleaner <NUM> according to the present disclosure. <FIG> is a lateral view of the robot cleaner <NUM> of <FIG>.

Referring to <FIG>, the robot cleaner <NUM> is configured to clean a floor while traveling in a predetermined area by itself. Cleaning the floor disclosed herein includes sucking dust and foreign materials on the floor or mopping the floor.

The robot cleaner <NUM> includes a cleaner main body <NUM> and a cleaning module <NUM>.

The cleaner main body <NUM> is provided with various components in addition to a controller (not illustrated) for controlling the robot cleaner <NUM>.

The cleaner main body <NUM> is provided with driving wheels <NUM> for autonomous traveling. The driving wheels <NUM> are rotatable by receiving driving force from a motor. A rotating direction of the motor may be controlled by the controller, and accordingly the driving wheels <NUM> may be rotatable in one direction or another direction.

The driving wheels <NUM> may be provided on both left and right sides of the cleaner main body <NUM>, respectively. The cleaner main body <NUM> may be moved or rotated forward, backward, left or right by the driving wheel <NUM>. Each of the driving wheels <NUM> may be configured to be driven independently of each other. To do so, each of the driving wheels <NUM> may be driven by a different motor.

The cleaner main body <NUM> may be provided with a sensing unit <NUM> for sensing a surrounding situation of the cleaner main body <NUM>. The controller may sense an obstacle, detect a land feature, or generate a map of a travel area through the sensing unit <NUM>.

The cleaning module <NUM> is configured to suck dust and foreign materials from a floor or to mop the floor.

When the cleaning module <NUM> is configured to suck dust and foreign substances on the floor, a housing <NUM> constituting appearance of the cleaning module <NUM> may be provided with an opening (not shown) for sucking air containing dust and foreign materials therethrough. The opening may be provided at a lower portion and arranged to face a bottom. The opening may communicate with a communication hole (not shown). The communication hole may be formed on an upper portion of the housing <NUM>.

A brush <NUM> which is configured to sweep dust on a floor by virtue of rotation may be mounted on the opening. The brush <NUM> may be detachably coupled to the opening.

Dust and foreign substances in the air sucked through the cleaning module <NUM> are filtered and collected in a dust collecting device <NUM> mounted in the cleaner main body <NUM>. Air separated from the dust and the foreign substances is discharged to outside of the cleaner main body <NUM>. The cleaner main body <NUM> may be provided therein with an intake flow path (not illustrated) through which the air sucked by the cleaning module <NUM> is guided into the dust collecting device <NUM>, and an exhaust flow path (not illustrated) through which air passed through the dust collecting device <NUM> is discharged to the outside of the cleaner main body <NUM>.

The dust collecting device <NUM> may be provided with at least one of a filter (not shown) and a cyclone (not shown) for filtering the dust and foreign materials in the sucked air. For example, the dust collecting device <NUM> may include a first cyclone for filtering dust having a large particle and a second cyclone for filtering fine dust having a small particle that have passed through the first cyclone.

When the cleaning module <NUM> is configured to mop the floor, a mop (not illustrated) may be detachably attached to the housing <NUM>. The mop may be attached to a lower surface of the housing <NUM> and configured to mop a floor in response to the movement of the robot cleaner <NUM>. Alternatively, the mop may be mounted in the opening 121a in place of the brush <NUM>. In this case, the mop is configured to be rotatable.

The cleaning module <NUM> may have both a function of sucking dust on the floor and a function of mopping the floor. The user may selectively attach or adhere the brush <NUM> or the mop to the housing <NUM> according to the cleaning purpose. Alternatively, the brush <NUM> and the mop module may be mounted together on the housing <NUM> to mop the floor after sucking the dust and foreign substances on the floor.

The cleaner module <NUM> may further include an auxiliary wheel <NUM>. The auxiliary wheel <NUM> supports the cleaner main body <NUM> together with the driving wheel <NUM> and assists traveling of a cleaner by the driving wheel <NUM>.

<FIG> is a conceptual view illustrating a state when the cleaning module <NUM> of <FIG> protrudes toward a front of the cleaner main body <NUM>. <FIG> is a lateral view of the robot cleaner <NUM> shown in <FIG>.

Referring to <FIG> and <FIG> together with <FIG> and <FIG>, the cleaning module <NUM> is configured to be relatively movable with respect to the cleaner main body <NUM>. In detail, the cleaning module <NUM> is configured to move away from the cleaner main body <NUM>, or to move close to the cleaner main body <NUM> when the cleaning module <NUM> is far from the cleaner main body <NUM>. The cleaning module <NUM> may be configured to protrude toward a front of the cleaner main body <NUM> corresponding to a direction in which the cleaner main body <NUM> moves forward.

<FIG> and <FIG> illustrate a first state when the cleaning module <NUM> is disposed adjacent to the cleaner main body <NUM>. <FIG> and <FIG> illustrate a second state when the cleaning module <NUM> protrudes from the cleaner main body <NUM>. The cleaning module <NUM> may be relatively movable with respect to the cleaner main body <NUM> between the first state and the second state, and may be fixed at any position between the first state and the second state. That is, an extent to which the cleaning module <NUM> protrudes from the cleaner main body <NUM> may be adjustable.

In the first state, a part of the cleaning module <NUM> may be arranged to overlap with the cleaner body <NUM> in a vertical direction.

A connection unit <NUM> is provided between the cleaner main body <NUM> and the cleaning module <NUM> to implement the relative movement of the cleaning module <NUM> with respect to the cleaner main body <NUM> as described above. The connection unit <NUM> is connected to the cleaner main body <NUM> and the cleaning module <NUM> respectively, and is configured to have a variable length.

That is, a length of the connection unit <NUM> is configured to be variable so that the cleaning module <NUM> moves relatively with respect to the cleaner main body <NUM>. In detail, when a length of the connection unit <NUM> is reduced, when the cleaning module <NUM> is disposed adjacent to the cleaner main body <NUM> (the first state). When a length of the connection unit <NUM> is extended, the cleaning module <NUM> is disposed to protrude from the cleaner main body <NUM> (the second state).

<FIG> is a conceptual view illustrating a structure in which the cleaning module <NUM> of <FIG> is relatively movable with respect to the cleaner main body <NUM>. <FIG> is a conceptual view illustrating disassembly of components of the structure of <FIG>. <FIG> and <FIG> are conceptual views illustrating the structure in the state of <FIG> and <FIG>, respectively.

Referring to <FIG>, the connection unit <NUM> includes a plurality of members configured to be relatively movable. In detail, as one member is configured to be relatively movable with respect to a fixed member, extension and reduction of a length of the connection unit <NUM> may be implemented.

In the invention, it is shown that the connection unit <NUM> includes an outer case <NUM> and an inner case <NUM>. The outer case <NUM> and the inner case <NUM> are provided longitudinally in one direction. The inner case <NUM> may be accommodated in a hollow portion of the outer case <NUM>.

The outer case <NUM> is mounted on the cleaner main body <NUM>. A degree of draw-in or draw-out of the inner case <NUM> is adjusted when the inner case <NUM> is inserted into the outer case <NUM>. Thus, the inner case <NUM> is relatively movable with respect to the outer case <NUM>.

The connection unit <NUM> may further include a connector <NUM> connected to the cleaning module <NUM> and the inner case <NUM> each.

The inner case <NUM> is directly connected to the cleaning module <NUM>. In this case, an end portion of the inner case <NUM> connected to the cleaning module <NUM> functions as a connector.

Referring back to <FIG>, the cleaning unit <NUM> may be disposed below the cleaner main body <NUM>. The dust collecting device <NUM> may be disposed on the connection unit <NUM>.

As shown in <FIG>, in the first state when the cleaning module <NUM> is disposed adjacent to the cleaner main body <NUM>, the inner case <NUM> is accommodated in the outer case <NUM> at maximum. The inner case <NUM> may be completely accommodated inside an outer case <NUM>.

On the other hand, as shown in <FIG>, the inner case <NUM> is drawn out of the outer case <NUM> at maximum in the second state when the cleaning module <NUM> is disposed to protrude from the cleaner main body <NUM>. Even in the second state, a part of the inner case <NUM> is accommodated in the outer case <NUM>.

In the first state, the cleaner main body <NUM> may be arranged to cover a part of the cleaning module <NUM>. As illustrated in <FIG>, the connector <NUM> may be covered by the cleaner main body <NUM>.

In the second state, the inner case <NUM> between the cleaner main body <NUM> and the cleaning module <NUM> may be exposed to outside. At this time, the connector <NUM> may also be exposed to outside.

A wheel 162a may be included on a lower part of the inner case <NUM>. In the second state, the wheel 162a is disposed between the cleaner main body <NUM> and the cleaning module <NUM> to support the inner case <NUM>.

In consideration of a structure in which the inner case <NUM> is relatively movable with respect to the outer case <NUM>, a cutout portion (not shown) may be provided on a lower portion of the outer case <NUM> along a longitudinal direction so that the wheel 162a is not caught by the outer case <NUM>.

The robot cleaner <NUM> includes a driving unit <NUM> that relatively moves the inner case <NUM> with respect to the outer case <NUM>. In this drawing, a rack-and-pinion structure is shown as an example of the driving unit <NUM>.

The connection unit <NUM> may include a guide structure for guiding relative movement of the inner case <NUM> with respect to the outer case <NUM> when the inner case <NUM> is relatively moved with respect to the outer case <NUM> by the driving unit <NUM>. In this drawing, a rail structure is shown as an example of the guide structure.

Referring to the driving unit <NUM> and the guide structure in the present embodiment in detail, a guide groove 161a is provided in the outer case <NUM> to extend in a longitudinal direction, and a guide rail 162b is provided to protrude from the inner case <NUM>, the guide groove 161a being inserted into the inner case <NUM> and guiding relative movement of the inner case <NUM> with respect to the outer case <NUM>. Positions in which the guide groove 161a and the guide rail 162b are provided may be exchanged with each other and interchangeably arranged.

The driving unit <NUM> may include a driving motor <NUM>, a double gear <NUM>, and a rack gear 162c.

A worm <NUM> is mounted on a rotating shaft 171a of the driving motor <NUM>. In a rack-and-pinion structure that is to be described later, the driving motor <NUM> may be disposed in a front end portion of the outer case <NUM> to maximize extension of a length of the inner case <NUM> with respect to the outer case <NUM>. To do so, a driving motor mounting portion 161b for fixing the driving motor <NUM> and a double gear <NUM> that is to be described later may be provided in the front end portion of the outer case <NUM>.

The driving motor <NUM> may be also fixed to a separate mechanism other than the outer case <NUM>.

A rack gear 162c is formed on the guide rail 162b. The rack gear 162c is disposed longitudinally along an extending direction of the guide rail 162b.

A driving force generated by the driving motor <NUM> is transmitted to the rack gear 162c by the double gear <NUM> connected to the worm <NUM>. The double gear <NUM> has a form in which a worm wheel 173a engaged with the worm <NUM> is combined with a pinion 173b.

The driving motor mounting portion 161b may receive the double gear <NUM>, and one end <NUM>' of a rotating shaft of the double gear <NUM> may be supported. The drive motor mounting portion 161b may be equipped with a cover member <NUM> provided to cover the double gear <NUM> and supporting another end <NUM>" of the rotation shaft of the double gear <NUM>.

The rotating shaft 171a of the drive motor <NUM> and the rotating shaft of the double gear <NUM> are arranged perpendicular to each other. The rotating shaft of the double gear <NUM> is disposed perpendicular to an extending direction of the rack gear 162c. Accordingly, the extending direction of the rack gear 162c corresponds to the rotating shaft 171a of the drive motor <NUM>.

In this structure, when the drive motor <NUM> is driven, the double gear <NUM> rotates and the pinion 173b of the double gear <NUM> moves between both ends of the rack gear 162c. Since the pinion 173b of the double gear <NUM> is in a fixed state, the inner case <NUM> in which the rack gear 162c is provided moves according to rotation of the double gear <NUM>. That is, the inner case <NUM> is relatively movable with respect to the fixed outer case <NUM>.

The above-described structure is described an example of the driving unit <NUM> in the rack-and-pinion structure, but the present disclosure is not limited thereto. A design of the driving unit <NUM> may be variously changed.

For example, the driving unit <NUM> may include the driving motor <NUM>, the pinion 173b, and the rack gear 162c. In this case, the pinion 173b is mounted on the rotating shaft 171a of the driving motor <NUM>, and the pinion 173b is arranged to be engaged with the rack gear 162c. The rotating shaft 171a of the driving motor <NUM> may be disposed perpendicular to the extending direction of the rack gear 162c.

When the cleaning module <NUM> is configured to suck dust and foreign substances on the floor, the connection unit <NUM> may form an intake flow path for guiding a flow of air sucked by the cleaning module <NUM> to the dust collecting device <NUM>. That is, the connection unit <NUM> not only relatively moves the cleaning module <NUM> with respect to the cleaner main body <NUM> as a length of the connection unit <NUM> varies, but also guides the air sucked by the cleaning module <NUM> to the dust collecting device <NUM>.

To do so, a hollow portion is provided in the inner case <NUM>, and the connection unit <NUM> includes a flexible tube <NUM> accommodated in the hollow portion of the inner case <NUM>. The flexible tube <NUM> is fixed to the outer case <NUM> and the inner case <NUM> each, and provided such that at least a part of the flexible tube <NUM> extends or contracts according to relative movement of the inner case <NUM> with respect to the outer case <NUM>.

In the first state, the flexible tube <NUM> contracts at maximum, and in the second state, the flexible tube <NUM> extends to maximum. In the first state, a corrugated portion 164a of the flexible tube <NUM> that is to be described later is completely accommodated in the inner case <NUM>. In the second state, the corrugated portion 164a of the flexible tube <NUM> may be provided throughout an inside of the inner case <NUM> and an inside of the outer case <NUM>.

In addition, the connector <NUM> described above and connected to the cleaning module <NUM> and the inner case <NUM> each is configured to supply air sucked by the cleaning module <NUM> to the inner case <NUM>. To do so, the connector <NUM> has a hollow portion, and the hollow portion may communicate with a communication hole of the cleaning module <NUM> and a hollow portion of the inner case <NUM>, respectively. In consideration of this function, the connector <NUM> may be referred to as a flow path connector <NUM>.

The flexible tube <NUM> may include the corrugated portion 164a including a ductile material and provided to extend or contract in accordance with relative movement of the inner case <NUM>. One end portion of the flexible tube <NUM> may be connected to the inner case <NUM> and the flow path connector <NUM>.

A hole 161c communicating with inside of the outer case <NUM> is provided in an outer circumference of the outer case <NUM>. The hole 161c may have a form open toward an upper portion of the cleaner main body <NUM>. In this drawing, the hole 161c is formed to have a slit shape. The hole 161c may have a size corresponding to an outer diameter of a bending portion 164b that is to be described later.

The flexible tube <NUM> includes the bending portion 164b extending from the corrugated portion 164a and penetrating the hole 161c. One end of the bending portion 164b may be inserted into the outer case <NUM> and another end of the bending portion 164b may extend through the hole 161c. The one end of the bending portion 164b is connected to the corrugated portion 164a. The another end of the bending portion 164b may extend upward toward the dust collecting device <NUM> disposed in an upper portion of the outer case <NUM>.

When the inner case <NUM> is drawn out of the outer case <NUM>, the bending portion 164b is locked by the outer case <NUM> (in detail, an inner circumferential surface of a front side of the hole 161c). That is, as the inner case <NUM> is drawn out of the outer case <NUM>, the corrugated portion 164a gradually expands when the bending portion 164b is locked by the outer case <NUM>.

A support portion 161d surrounding a front of the hole 161c may be provided to protrude from the outer case <NUM>. The support portion 161d is configured to support a front of the bending portion 164b when the inner case <NUM> relatively moves with respect to the outer case <NUM>. The support portion 161d may be provided to completely surround the hole 161c.

When the support portion 161d is not provided, the bending portion 164b is locked only in an inner circumferential surface of a front side of the hole 161c. In this process, since stress may be concentrated on a portion of the locking of the bending portion 164b, a possibility of damage to the bending portion 164b increases. However, in the above-described structure, there is such an advantage that the bending portion 164b is supported by the support portion 161d having a large area so that a risk of the damage may be reduced.

A cutout portion 162d may be provided along a longitudinal direction in the inner case <NUM> to prevent interference with the bending portion 164b when the inner case <NUM> relatively moves with respect to the outer case <NUM>. In this drawing, it is shown that the cutout portion 162d is provided on an upper part of the inner case <NUM>.

When the inner case <NUM> is drawn out of the outer case <NUM>, the flexible tube <NUM> may be exposed to outside through the cutout portion 162d.

<FIG> is a conceptual view illustrating an example of using the robot cleaner <NUM> of <FIG>.

Referring to <FIG>, since the dust collecting device <NUM> is provided in the cleaner main body <NUM>, the cleaner main body <NUM> is provided to have a height greater than that of the cleaning module <NUM>. Therefore, the cleaner main body <NUM> may not enter an area B (e.g., under a sofa as shown in <FIG>) of which a height is less than that of the cleaner main body <NUM>.

However, in the present disclosure, since a length of the connection unit <NUM> extends and the cleaning module <NUM> protrudes from the cleaner main body <NUM>, the cleaning module <NUM> may enter the area B and perform cleaning.

To do so, the controller may sense whether a length of the cleaning module <NUM> needs to extend, using the sensing unit <NUM>. For example, the controller may obtain various information (a shape, a height, etc.) regarding an obstacle A in front of the cleaning main body <NUM> using the sensing unit <NUM>, and thus sense whether the cleaning module <NUM> may enter the area B below the obstacle A even when the cleaning main body <NUM> may enter the area B.

As a result of the sensing, when a length of the cleaning module <NUM> needs to extend, a length of the connection unit <NUM> is extended so that the cleaning module <NUM> protrudes from the cleaner main body <NUM>. For example, when the cleaning module <NUM> may enter the area B below the obstacle A, the driving motor <NUM> may be driven to draw the inner case <NUM> out of the outer case <NUM>.

Therefore, the cleaning module <NUM> may enter the area B below the obstacle A that the cleaner main body <NUM> may not enter, and perform cleaning. When the cleaning of the area B below the obstacle A is finished, the controller may reduce a length of the connection unit <NUM> to arrange the cleaning module <NUM> adjacent to the cleaner main body <NUM>.

Claim 1:
A robot cleaner comprising:
a cleaner main body (<NUM>) equipped with a dust collecting device (<NUM>);
a cleaning module (<NUM>) that is relatively movable with respect to the cleaner main body (<NUM>) and sucks air containing dust and foreign substances; and
a connection unit (<NUM>) that is connected to the cleaner main body (<NUM>) and the cleaning module (<NUM>) respectively and has a variable length,
wherein the connection unit (<NUM>) forms a part of an intake flow path that guides the air sucked by the cleaning module (<NUM>) to the dust collecting device (<NUM>),
wherein the connection unit (<NUM>) comprises:
an outer case (<NUM>) mounted on the cleaner main body (<NUM>),
an inner case (<NUM>) that is inserted into the outer case (<NUM>) and relatively moveable with respect to the outer case (<NUM>), and
a flexible tube (<NUM>) which is fixed to the outer case (<NUM>) and the inner case (<NUM>), respectively, and of which at least a part is provided to extend or contract according to the relative movement of the inner case (<NUM>),
characterized in that a hole (161c) connecting with inside of the outer case (<NUM>) is provided on an outer circumference of the outer case (<NUM>), and
wherein the flexible tube (<NUM>) comprises a corrugated portion (164a) including a ductile material and provided to extend or contract according to the relative movement of the inner case (<NUM>), and a bending portion (164b) extending from the corrugated portion (164a) and penetrating the hole (161c).