JP2007198056A - Carrier plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve productivity, by shortening the molding time for a carrier plate, by firmly installing a cover member for covering a winding drum in an installation part not to move by tensile force of a wire. <P>SOLUTION: A plate body 15 is provided with the installation part 43 composed of a solid layer and having a drum inserting hole for inserting the winding drum 55. The cover member 59 is provided with a storage part 59a covering the winding drum 55, a flange part 59b and guide parts 61a and 61b arranged in the flange part 59b and guiding the wire 57. The flange part 59b is fastened to a part surrounding the drum inserting hole in the installation part 43. The installation part 43 is provided with first and second boss parts 51 and 53 for checking the movement of the cover member 59 by the tensile force acting on the guide parts 61a and 61b from the wire 57, by engaging with the flange part 59b of the cover member 59. The first and second boss parts 51 and 53 has a hollow shape of projecting to the cover member 59 side and opening on the opposite side of the projection side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a carrier plate for a vehicle door to which a motor for raising and lowering a wind glass is attached.

  Conventionally, a resin molded product in which a skin layer is formed on the surface and an expanded layer having a large number of voids is formed therein is known (see, for example, Patent Document 1). In the molding of the resin molded product, first, a fiber-filled thermoplastic resin is injected and filled into a cavity in a state where a mold composed of a movable mold and a stationary mold containing a movable mold is closed. Next, in the process in which the fiber-containing thermoplastic resin is solidified in the cavity, the movable mold is retracted in the moving mold in the direction of increasing the cavity volume. In this way, the expansion layer is formed over the entire area of the resin molded product to reduce the weight of the resin molded product. Furthermore, the convex part which consists of a solid layer with a high resin density is provided in at least one surface of the thickness direction of the resin molded product, and this convex part is functioning as a rib. This compensates for a decrease in strength against shearing force and compressive force due to the provision of the expansion layer.

On the other hand, a window regulator for raising and lowering a window glass of a side door of a vehicle is known (for example, see Patent Document 2). This window regulator moves a slider bracket, to which a window glass is attached, up and down along a guide rail attached to a carrier plate. Specifically, the slider bracket is attached to a wire wound around the winding drum. The winding drum is covered by a cover member that is rotated by the operation of a motor for raising and lowering the wind glass and is attached to the attachment portion of the carrier plate. The cover member is provided with a guide portion for guiding the wire up and down. The winding drum is rotated by the operation of the motor to wind the wire, and the slider bracket moves up and down.
Japanese Patent Laid-Open No. 11-179751 Japanese Patent Laid-Open No. 8-319759

  However, in the window regulator disclosed in Patent Document 2, when the wire is wound, a tensile force acts on the guide portion of the cover member that supports the wire. For this reason, it is necessary to firmly attach the cover member to the attachment portion so that the cover member does not move. Therefore, in order to prevent the movement of the cover member, it is conceivable to provide a boss portion that engages with the cover member in the attachment portion. However, when the boss part is a solid shape constituted by a solid layer like the convex part provided in the resin molded product of Patent Document 1, the boss part at the time of molding is compared with other parts of the carrier plate. Takes time to cool. For this reason, there is a problem that the waiting time of the cooling process becomes long, and the molding time of the carrier plate as a whole becomes long and the productivity is lowered.

  The present invention has been made in view of such a point, and the object of the present invention is to prevent the cover member covering the winding drum around which the wire for raising and lowering the window glass is wound from moving by the tensile force of the wire. The object is to firmly attach to the attachment part of the carrier plate and reduce the molding time of the carrier plate to improve its productivity.

  In order to achieve the above object, in the present invention, the boss portion provided in the attachment portion is formed into a hollow shape having an opening on the opposite side to the protruding side.

  Specifically, it is a carrier plate for a vehicle door to which a motor for raising and lowering a windshield is attached, and in the process where the thermoplastic resin injected and filled into the cavity of the mold is solidified, the cavity volume is enlarged and the above-mentioned A skin layer is formed on the surface by inflating the thermoplastic resin, and a plate-like plate body having an expanded layer having a large number of voids formed therein is provided. The plate body has a cavity volume at the time of molding. Is provided with a mounting portion having a drum insertion hole through which a winding drum around which a wire for raising and lowering the wind glass is wound is inserted. A bottomed cylindrical storage portion covering the winding drum protruding from the drum insertion hole, a flange portion extending outward from the opening of the storage portion, and the flange portion The flange portion of the cover member, which is provided and has a guide portion for guiding the wire, is fastened by a bolt to a portion surrounding the drum insertion hole in the attachment portion, and the flange portion of the cover member is attached to the attachment portion. When the wire is wound up, a boss portion is provided to prevent the cover member from moving due to a tensile force acting on the guide portion from the wire, and the boss portion protrudes to the cover member side, It was set as the structure which has the hollow shape which the other side of the protrusion side opened.

  According to the above invention, the cover member is fastened to the attachment portion of the plate body at the flange portion, and is engaged with the boss portion provided on the attachment portion. For this reason, when the wire is wound, the movement of the cover member due to the tensile force acting on the guide portion from the wire is prevented by the boss portion, so that the bolt that fastens the cover member to the mounting portion is repeated. The cover member does not rattle when it is loosened due to the opening / closing operation of the door or the vibration caused by traveling of the vehicle. Therefore, the cover member can be securely attached to the attachment portion stably over a long period of time. In addition, the boss portion protrudes toward the cover member and has a hollow shape that is open on the opposite side to the protruding side. That is, since the boss part has a concave shape having the same thickness as the other part of the attachment part, the cooling time at the time of forming the boss part becomes the same time as the other part of the attachment part. For this reason, compared with the case where the boss part is a solid shape made of a solid layer, the waiting time of the cooling process at the time of molding is shortened, the molding time of the carrier plate can be shortened, and the productivity can be improved. it can. In addition, by forming the boss part, the number of parts can be reduced compared to the case where the boss part is a bolt. As a result, the man-hours for assembling the cover member, the mass of the carrier plate, and the parts cost of the bolt are reduced. can do. The boss portion can be easily formed simultaneously with the forming of the carrier plate.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a sectional view of a side door 1 of an automobile. The side door 1 includes a door body 3 having a metal door outer panel 5 and a door inner panel 7. A carrier plate 9 is attached to the door inner panel 7. A door trim 13 is attached to the door inner panel 7 so as to cover the carrier plate 9 from the vehicle interior side.

  FIG. 2 is a plan view of the carrier plate 9 for the right front door of the automobile as viewed from the outside of the passenger compartment. In FIG. 2, the right side indicates the front side of the vehicle, and the upper side indicates the upper side of the vehicle. The carrier plate 9 includes a plate main body 15 as a main body of the molded body that forms the main body. The carrier plate 9 is formed of a fiber-containing thermoplastic resin R (shown in FIG. 6).

  As shown in FIG. 1, the plate body 15 has a hard skin layer 21 with no voids and high resin density formed on the surface, and has a large number of voids (not shown), and is surrounded by the skin layer 21. An expansion layer 23 having a resin density lower than that of the skin layer 21 is formed inside. Although details will be described later, the plate body 15 expands the cavity volume corresponding to the plate body 15 in the process of solidifying the fiber-filled thermoplastic resin R injected and filled in the cavity 77 (shown in FIG. 5) of the mold 69. And it shape | molds by expanding the thermoplastic resin R containing a fiber.

  As shown in FIGS. 1 and 2, a sealing material 11 that seals between the plate main body 15 and the door inner panel 7 is accommodated in the seal groove portion 17 formed on the outer peripheral edge portion of the outer side surface of the plate main body 15. Has been. On the inner periphery of the seal groove portion 17 of the plate body 15, a plurality of panel attachment portions 19 that are attachment locations of the carrier plate 9 to the door inner panel 7 are formed. Each of the panel attachment portions 19 is formed with a bolt insertion hole 19a therethrough, and the bolt insertion hole 19a is aligned with a plurality of attachment holes 7b (shown only in FIG. 1) of the door inner panel 7. The carrier plate 9 is attached to the door inner panel 7 by screwing the bolts 25 to the weld nuts 27 welded to the outside of the passenger compartment of the door inner panel 7. The panel mounting portion 19 of the plate body 15 is formed in the vicinity of the outside of the opening 7 a formed at the center portion of the door inner panel 7.

  The front and rear guide rails 29a and 29b for raising and lowering the wind glass (not shown) are attached to the outer side of the passenger compartment of the plate body 15 by bolts 31 at two locations on the upper side and the lower side, respectively. Yes.

  Guide portions 33a and 33b are provided over the entire longitudinal direction on the front side of the front guide rail 29a and the rear side of the rear guide rail 29b. Front and rear slider brackets 35a and 35b are slidably fitted to the guide portions 33a and 33b, respectively. Wind glass attachment portions 37a and 37b are formed on the front and rear slider brackets 35a and 35b, and the lower end of the wind glass is attached to the window glass attachment portions 37a and 37b. The front and rear slider brackets 35a and 35b are provided with wire attachment portions 39a and 39b to which wires are fixed, respectively. Upper and lower pulleys 41a and 41b are provided at the upper and lower ends of the front and rear guide rails 29a and 29b, respectively.

  A mounting portion 43 that is recessed toward the outside of the passenger compartment is provided at the center of the plate body 15 (see FIGS. 3 and 4). This attachment portion 43 is shown enlarged in FIG. As will be described later, the attachment portion 43 is formed without increasing the cavity volume during molding, and is configured by a solid layer 40 having a high resin density that does not have the expansion layer 23. A cover member 59, which will be described later, is attached to the attachment portion 43 through which the take-up drum 55 (shown in phantom lines in FIG. 3) is inserted. For this reason, the attachment part 43 is comprised by the solid layer 40 with high resin density which does not have the expansion layer 23, and the strength with respect to the compressive strength and shearing force of the attachment part 43 to which local stress acts can be raised. A drum insertion hole 45 is formed in the center of the attachment portion 43. Three ribs 47 extending in the vertical direction are formed at the front end of the attachment portion 43. First to third cover fastening holes 49a, 49b, 49c are formed above, in front of, and substantially below the drum insertion hole 45 of the attachment portion 43.

  A first boss portion 51 having a substantially oval shape in plan view is formed at a substantially center of the rear end of the attachment portion 43, and a second boss portion 53 having a circular shape in plan view is formed below the first boss portion 51. Is formed. As shown in FIG. 4, the 1st boss | hub part 51 consists of the solid layer 40, and is formed in the hollow shape provided with the opening part 51a so that it may protrude toward the vehicle interior outer side and the vehicle interior side may be formed in a concave shape. Yes. Similarly, the second boss portion 53 protrudes toward the outside of the passenger compartment and is formed in a hollow shape having an opening 53a that is open so that the inner side of the passenger compartment is formed in a concave shape.

  A wind glass raising / lowering motor (not shown) is attached to the vehicle interior side of the attachment portion 43, and a winding drum 55 (shown by a broken line in FIG. 2) driven (rotated) by the motor is provided in the drum insertion hole. A wire 57 is wound around the outer peripheral surface of the take-up drum 55.

  As shown in FIG. 2, at the portion surrounding the drum insertion hole 45 on the outside of the passenger compartment of the mounting portion 43, a bottomed cylindrical storage portion 59 a that covers the winding drum 55 protruding from the drum insertion hole 45, and a storage portion A cover member 59 having a flange portion 59b that extends outward from the opening of 59a and upper and lower guide portions 61a and 61b that guide the wire 57 is fastened. Cover-side fastening holes (not shown) are respectively formed at positions corresponding to the first to third cover fastening holes 49a, 49b, 49c of the mounting portion 43 of the flange portion 59b. Further, at positions corresponding to the first and second boss portions 51 and 53 of the mounting portion 43 of the flange portion 59b, first and second engagement holes 63a and 63b are respectively part of the periphery of the flange portion 59b. Is formed to be cut out. Then, the cover member 59 is overlapped on the attachment portion 43 from the outside of the passenger compartment, and the cover side fastening holes 49a, 49b, and 49c are aligned with the first to third cover fastening holes 49a, and then the bolts 61 are attached from the outer side of the passenger compartment. The cover member 59 is fastened to the mounting portion 43 by inserting and screwing a nut (not shown) into the bolt 61 from the vehicle interior side of the mounting portion 43. At the same time, the first and second boss portions 51 and 53 are fitted into and engaged with the first and second engagement holes 63a and 63b. Here, when the first and second engagement holes 63a and 63b are closed holes having a substantially oval shape or a circular shape in plan view corresponding to the shapes of the first and second boss portions 51 and 53, the first If the positions and shapes of the second engagement holes 63a and 63b are slightly shifted due to manufacturing errors, both the first and second boss portions 51 and 53 are connected to the first and second engagement holes 63a and 63b. It becomes difficult to insert and fit into 63b, and the assembly becomes impossible. However, since the first and second engagement holes 63a and 63b are formed so that the peripheral edge of the flange portion 59b is cut away, the cover member 59 is moved from the front to the first and second boss portions 51 and 53. Since the first and second boss portions 51 and 53 are fitted into the first and second engagement holes 63a and 63b, the first and second engagement holes 63a and 63b can be easily engaged with each other. Assembly to the part 43 is easy.

  The upper and lower guide portions 61 a and 61 b are provided at the rear upper end and lower end of the cover member 59. The upper and lower guide portions 61a and 61b include upper and lower wire holders 65a and 65b for supporting the wire 57 so as to be slidable and preventing the wire 57 from sagging. The lower end of the upper tube member 67a is inserted through the upper wire holder 65a. A wire 57 is inserted through the upper tube member 67a from the upper guide portion 61a to the upper pulley 41a of the rear guide rail 29b. The upper end of the lower tube member 67b is inserted into the lower wire holder 65b. The lower tube member 67b is inserted with a wire 57 that extends from the lower guide portion 61b to the lower pulley 41b of the front guide rail 29a.

  One end side of the wire 57 wound around the take-up drum 55 is inserted into the upper wire holder 65a, passes through the upper tube member 67a, and passes through the upper pulley 41a of the rear guide rail 29b, and the rear slider bracket 35b. It is fixed to the wire attachment portion 39b. The other end of the wire 57 is inserted into the lower wire holder 65b, passes through the lower tube member 67b, and is fixed to the wire attachment portion 39a of the front slider bracket 35a via the lower pulley 41b of the front guide rail 29a. Has been. The other end side of the wire 57 is further connected to the wire attachment portion 39b from the wire attachment portion 39a via the upper pulley 41a of the front guide rail 29a and the lower pulley 41b of the rear guide rail 29b. It is connected to one end side.

  When the wind glass is raised, if the motor is operated to rotate the winding drum 55 counterclockwise, the wire 57 on the upper wire holder 65a side is wound around the winding drum 55, and the lower wire holder 65b. The side wire 57 is fed out. Thereby, the windshield rises by raising the front and rear slider brackets 35a and 35b. At this time, since the upper wire holder 65a that supports the wire 57 has sliding resistance of the wire 57, a tensile force in the F1 direction shown in FIG. As a result, a force that causes the cover member 59 to rotate counterclockwise from the wire 57 acts on the upper guide portion 61a. On the other hand, when the window glass is lowered, if the motor is operated to rotate the winding drum 55 clockwise, the wire 57 on the lower wire holder 65b side is wound around the winding drum 55, and the upper wire holder The wire 57 on the 65a side is fed out. Thereby, the windshield is lowered by lowering the front and rear slider brackets 35a and 35b. At this time, since the lower wire holder 65b has a sliding resistance of the wire 57, the tensile force in the F2 direction shown in FIG. As a result, a force that the cover member 59 rotates clockwise acts on the lower guide portion 61b. However, the cover member 59 is fastened to the attachment portion 43 of the plate body 15 at the flange portion 59 b by the bolt 61 and is engaged with the first and second boss portions 51 and 53 provided on the attachment portion 43. For this reason, when the wire 57 is wound up, the movement of the cover member 59 by the tensile force in the F1 or F2 direction acting on the upper guide portion 61a or the lower guide portion 61b from the wire 57 is caused to move to the first and second boss portions 51. 53, when the bolt 61 that fastens the cover member 59 to the mounting portion 43 is loosened due to repeated opening / closing operations of the side door 1, vibrations caused by traveling of the vehicle, or the like. There is no backlash. Therefore, the cover member 59 can be stably and firmly attached to the attachment portion 43 over a long period of time.

  Next, a method for forming the carrier plate 9 according to this embodiment will be described.

  FIG. 5 shows a portion corresponding to the cross section taken along line IV-IV in FIG. 3, that is, a forming die 69 for forming in FIG.

  The forming die 69 includes a fixed die 71, a movable die 73 disposed so as to face the fixed die 71, and a slide die 75 provided on the fixed die 71. The molding surface 71 a of the fixed die 71 corresponds to the shape of the side surface of the vehicle interior of the plate body 15. The molding surface 73a of the movable mold 73 corresponds to the shape of the vehicle interior side surface of the plate body 15, and the molding surface 75a of the slide mold 75 corresponds to the shape of the vehicle interior side surface of the mounting portion 43 near the first boss portion 51. ing. The slide mold 75 is movably inserted into the fixed mold 71 and connected to expansion / contraction means (not shown) such as a hydraulic cylinder. The expansion / contraction operation of the expansion / contraction means allows the slide mold 75 to move forward and backward. .

  First, as shown in FIG. 5A, the mold 69 is closed.

  Next, the cavity 77 is filled with a thermoplastic resin R containing fibers such as glass fibers (for example, polypropylene resin containing fibers) from an injection machine (not shown).

  Thereafter, in the process of solidifying the fiber-containing thermoplastic resin R in the cavity 77 of the mold 69, as shown in FIG. 5B, the movable mold 73 is opened in the mold opening direction in which the volume of the cavity 77 is increased (FIG. Retreat to b) (indicated by white arrow). In other words, the movable mold 73 is slightly separated from the fixed mold 71, and the cavity volume is increased, for example, twice or more. The process of solidifying the fiber-containing thermoplastic resin R is the time when the skin layer 21 is generated in the vicinity of the molding surfaces 71a, 73a, 75a of the molding die 69 (fixed die 71, movable die 73, slide die 75) in the cavity 77. It is.

  Following the backward movement of the movable mold 73, the slide mold 75 is further advanced into the cavity 77 toward the movable mold 73 by the extension operation of the expansion / contraction means. For this reason, the cavity volume at the location corresponding to the slide mold 75 does not fluctuate (enlarge).

  In the above-described stage, the thermoplastic resin R containing fibers in the cavity 77 between the molding surface 71a of the fixed mold 71 excluding the slide mold 75 and the molding surface 73a of the movable mold 73 is in contact with these molding surfaces 71a and 73a. Since the part to be cooled is cooled early due to the influence of the mold temperature, the surface layer is constituted by a hard skin layer 21 without voids, while the inner part of the fiber-containing thermoplastic resin R is influenced by the mold temperature. It is difficult to receive and is in a highly viscous gel state. Therefore, as the cavity volume increases, the fiber-containing thermoplastic resin R that has been compressed by the fixed mold 71 and the movable mold 73 is pulled by the molding surface 73 a of the movable mold 73 and expands. At this time, the fiber-containing thermoplastic resin R is also released from the compression and elastically restored, and the fiber-containing thermoplastic resin R expands by this elastic restoring force (spring back phenomenon). As a result, the plate body 15 in which the stiff skin layer 21 with few voids is formed on the surface and the expansion layer 23 having a large number of voids is formed therein is formed.

  The fiber-containing thermoplastic resin R in the cavity 77 corresponding to the mounting portion 43 moves into the cavity 77 by following the retracting operation even if the movable mold 73 is retracted in the cavity volume expansion direction. The cavity space is not enlarged, and therefore the mounting portion 43 made of the solid solid layer 40 is formed.

  Finally, the molded product can be removed by retracting the movable mold 73 and opening the mold 69.

  Here, the first and second boss portions 51 and 53 protrude to the cover member 59 side (vehicle compartment outer side), and have a hollow shape that is open on the opposite side (vehicle interior side) of the protruding side. That is, since the first and second boss portions 51 and 53 have a concave shape having the same thickness as the other portions of the attachment portion 43, the cooling time during molding of the first and second boss portions 51 and 53 is The time is about the same as the other portions of the attachment portion 43. For this reason, compared with the case where the 1st, 2nd boss parts 51 and 53 are solid shape which consists of solid layers 40, waiting time of the cooling process at the time of fabrication becomes short, and the molding time of carrier plate 9 is shortened. Thus, the productivity can be improved. Further, by forming the first and second boss portions 51 and 53, the number of parts can be reduced as compared with the case where the first and second boss portions 51 and 53 are bolts. The number of assembling steps and the mass of the carrier plate 9 can be reduced, and the cost of bolt parts can be reduced. The first and second boss portions 51 and 53 can be easily formed simultaneously with the molding of the carrier plate 9.

<< Other Embodiments >>
In addition, the above-mentioned embodiment is an illustration of this invention, Comprising: This invention is not limited to this example.

  For example, the following configuration may be used.

  That is, in the said embodiment, although the 1st, 2nd boss | hub parts 51 and 53 were provided in the attachment part 43, there should just be at least 1 boss | hub part, and the shape is also substantially oval shape and circular shape by planar view. However, it is not limited to this shape.

  In the above embodiment, the first and second engagement holes 63a and 63b are formed so as to cut out a part of the periphery of the flange portion 59b, but one of the second engagement holes 63b, for example, A closed hole having a circular shape in plan view corresponding to the shape of the second boss portion 53 may be used, and the other, for example, the first engagement hole 63a may be partially cut out as described above. In this case, after the second boss portion 53 is inserted into the second engagement hole 63b, the cover member 59 is rotated around the second boss portion 53, and the first boss portion 51 is fitted into the first engagement hole 63a. Since these can be engaged with each other, the second boss portion 53 has a positioning function, and the assembly accuracy of the cover member 59 to the attachment portion 43 is good.

  Moreover, in the said embodiment, it is desirable to make the thermoplastic resin R containing a fiber contain a foaming material. When the retraction amount of the movable mold 73, that is, the expansion magnification is increased to increase the thickness (plate thickness) of the plate body 15 in the retraction direction of the movable mold 73, even if the expansion amount of the fiber-containing thermoplastic resin R is insufficient, This is because the foaming force (expansion pressure) of the foam material complements it, and the voids can be reliably formed. In these cases, examples of the foam material include a scientific foam material that generates a gas by a chemical reaction, and a physical foam material that uses an inert gas such as carbon dioxide gas and nitrogen gas.

  As described above, the present invention is useful for a carrier plate for a vehicle door to which a motor for raising and lowering a window glass is attached.

FIG. 3 is a cross-sectional view of a side door of an automobile taken along line II in FIG. 2. It is the top view which looked at the carrier plate which concerns on embodiment of this invention from the vehicle interior outer side. It is a top view which expands and shows the attaching part of a carrier plate. It is sectional drawing in the IV-IV line of FIG. 4A is a cross-sectional view of a molding die corresponding to FIG. 4 showing a state in which a fiber-filled thermoplastic resin is injected and filled in the cavity, and FIG. 4B is a diagram in which the movable die is slightly retracted in the direction in which the cavity volume increases. FIG.

Explanation of symbols

1 Side door (vehicle door)
9 Carrier plate 15 Plate body 21 Skin layer 23 Expanding layer 40 Solid layer 43 Mounting portion 45 Drum insertion hole 51 First boss portion (boss portion)
53 Second Boss (Boss)
55 Winding drum 57 Wire 59 Cover member 59a Storage part 59b Flange part 61a Upper guide part (guide part)
61b Lower guide part (guide part)
69 Mold 77 Cavity R Fiber-containing thermoplastic resin

Claims (1)

A carrier plate for a vehicle door to which a motor for raising and lowering the windshield is attached,
In the process of solidifying the injection-filled thermoplastic resin in the mold cavity, the cavity volume is expanded to expand the thermoplastic resin, thereby forming a skin layer on the surface and expanding with a large number of voids. A plate-like plate body with a layer formed inside,
The plate body is formed of a solid layer formed without expanding the cavity volume at the time of molding, and is a drum into which a winding drum around which a wire for raising and lowering the wind glass is wound is inserted by being rotated by the motor. A mounting portion having an insertion hole is provided,
A bottomed cylindrical storage portion that covers the winding drum protruding from the drum insertion hole, a flange portion that extends outward from the opening of the storage portion, and a guide portion that is provided in the flange portion and guides the wire The flange portion of the cover member having a bolt is fastened by a bolt to a portion surrounding the drum insertion hole in the attachment portion,
The mounting portion is provided with a boss portion that engages with the flange portion of the cover member and prevents movement of the cover member due to a tensile force acting on the guide portion from the wire when the wire is wound.
The carrier plate according to claim 1, wherein the boss portion has a hollow shape that protrudes toward the cover member and opens on the opposite side of the protrusion side.

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