The present disclosure relates to a resin component that includes an internal thread member used to fix a member-to-be-fastened-and-fixed.
An attachment structure has been developed that attaches a fastening-fixing internal thread member to a fixation object member (for example, Patent Document 1). A member-to-be-fastened-and-fixed is fixed to the fixation object member with a fastening-fixing bolt. The attachment structure of Patent Document 1 includes an accommodating member made of a synthetic resin. The accommodating member accommodates a nut. The accommodating member is attached to the back of the fixation object member (for example, a door panel for an automobile) without causing the member-to-be-fastened-and-fixed (speaker) to contact the nut. In Patent Document 1, the fastening-fixing bolt is threaded into the nut with the outer peripheral portion of the speaker held between the accommodating member and the bolt (specifically, the head of the bolt). Accordingly, the speaker (the member-to-be-fastened-and-fixed) is fastened and fixed to the automobile door panel (fixation object member).
The internal thread member of Patent Document 1 includes an accommodating member made of a synthetic resin and a metal nut accommodated in the accommodating member. The internal thread member is attached to the back of the automobile door panel. The fastening-fixing bolt is threaded into the nut with the outer peripheral portion of the speaker held between the internal thread member and the bolt (specifically, the head of the bolt). Accordingly, the speaker is fastened and fixed to the door panel.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2012-52599
In order to build a firm fixation structure through a fastening-fixing operation using an internal thread member (for example, a nut), metal-to-metal contact is preferably established between portions that are fastened and fixed to each other.
In a case in which a member-to-be-fastened-and-fixed is fixed to a synthetic resin component, it is difficult to establish metal-to-metal contact between portions that are fastened and fixed to each other. The attachment structure of Patent Document 1 may be employed to attach a nut to a resin component. In such a case, an accommodating member made of a synthetic resin is disposed between the nut and the member-to-be-fastened-and-fixed in the attachment structure. Thus, metal-to-metal contact is not established between the portions that are fastened and fixed to each other.
In a case in which the above-described internal thread member is used with a resin component, it is typical that the internal thread member will be replaced during repair of the resin component and that the internal thread member including a metal component (nut) will be removed from the fixation object member when the resin component is recycled. The above-described internal thread member is fixed to the back of the fixation object member (door panel), to which the internal thread member is fixed. Therefore, if the structure of the fixation object member or the structure surrounding the fixation object member is complicated, the internal thread member may be difficult to attach to or remove from the fixation object member.
Accordingly, it is an objective of the present disclosure to provide a resin component that achieves fastening and fixing of a member-to-be-fastened-and-fixed while establishing metal-to-metal contact.
Also, it is an objective of the present disclosure to provide a resin component that allows an internal thread member to be easily attached and removed to and from the resin component.
In accordance with one aspect of the present disclosure, a resin component is provided that includes an internal thread member configured to be used to fasten and fix a member-to-be-fastened-and-fixed made of a metallic material, and a component body made of a synthetic resin, the internal thread member being attached to the component body. The internal thread member includes a thread main body made of a synthetic resin, and a nut portion made of a metallic material. The nut portion includes an internal thread. The nut portion is integrated with the thread main body in a state in which an end face of the nut portion on one side in a fastening direction of the internal thread is exposed. The end face of the nut portion is exposed to an outside in a state in which a protruding amount of the end face of the nut portion from an outer surface of the component body is greater than or equal to zero.
With the above-described configuration, the end face of the nut portion (metallic material) of the internal thread member is exposed to the outside of the resin component. Thus, when the member-to-be-fastened-and-fixed is fastened and fixed to the resin component, the member-to-be-fastened-and-fixed and the end face of the nut portion are brought into contact with each other by arranging the member-to-be-fastened-and-fixed at a proper position. Thus, when the member-to-be-fastened-and-fixed is fastened and fixed to the resin component using the internal thread member (specifically, the internal thread of the internal thread member) in this contacting state, the member-to-be-fastened-and-fixed is fastened and fixed to the resin component with the member-to-be-fastened-and-fixed and the end face of the nut portion contacting each other (in a metal-to-metal contact state).
In accordance with another aspect of the present disclosure, a resin component is provided that includes an internal thread member including an internal thread used to fix a member-to-be-fastened-and-fixed, and a component body made of a synthetic resin, the component body having an attachment hole into which the internal thread member is inserted. An engagement groove is provided in one of an inner circumferential surface of the attachment hole and an outer circumferential surface of the internal thread member. An engagement protrusion is provided on the other one of the inner circumferential surface of the attachment hole and the outer circumferential surface of the internal thread member. The engagement groove extends in a peripheral direction of the internal thread member. The engagement groove and the engagement protrusion are engaged with each other. The component body includes a first fixation surface on a side on which the member-to-be-fastened-and-fixed is fixed. The first fixation surface includes a guiding protrusion and a fitting recess. The internal thread member includes an engagement arm having a cantilever-like structure. The engagement arm extends in the peripheral direction. The engagement arm is configured to be elastically deformed such that a free end of the engagement arm swings. The engagement arm includes a fitting protrusion. The fitting protrusion is provided on a surface facing the component body in a section of the engagement arm that corresponds to the free end. The guiding protrusion of the component body and the fitting protrusion of the engagement arm are arranged side-by-side in the peripheral direction. The fitting protrusion of the engagement arm and the fitting recess of the component body are opposed to each other in the fastening direction of the internal thread. The internal thread member includes a second fixation surface on a side on which the member-to-be-fastened-and-fixed is fixed. A section of the engagement arm protrudes further than the first fixation surface and the second fixation surface.
With the above-described configuration, the internal thread member is inserted into the attachment hole of the component body toward the surface of the component body on the side to which the member-to-be-fastened-and-fixed is fixed (the first fixation surface). Accordingly, the component body and the internal thread member are rotated relative to each other such that the engagement groove, which is provided in one of the component body and the internal thread member and extends in the peripheral direction (circumferential direction), receives the engagement protrusion, which is provided on the other one of the component body and the internal thread member. This operation restricts movement in the fastening direction of the internal thread member relative to the component body. Further, when the fitting protrusion of the engagement arm abuts the guiding protrusion of the component body during the relative rotation between the component body and the internal thread member, the engagement arm is elastically deformed. This allows the fitting protrusion of the engagement arm to pass while avoiding the section of the component body in which the guiding protrusion is disposed. As a result, the fitting protrusion and the guiding protrusion are arranged side-by-side in the peripheral direction. The direction in which the internal thread member is rotated when attached to the component body is referred to an attachment direction. The rotation direction opposite to the attachment direction is referred to a removal direction. The above-described engagement between the fitting protrusion of the engagement arm and the guiding protrusion of the component body restricts rotation of the internal thread member in the removal direction. The above-described configuration facilitates attachment of the internal thread member to the component body from the side facing the first fixation surface, that is, from the section in which the space for fixing the member-to-be-fastened-and-fixed is secured.
Further, when the internal thread member is removed from the component body, the engagement arm is elastically deformed such that the fitting protrusion of the engagement arm and the guiding protrusion of the component body are no longer arranged side-by-side in the peripheral direction. Such a simple operation allows the internal thread member to be rotated in the removal direction. The internal thread member is removed from the component body by rotating the internal thread member in the removal direction in a state in which the engagement protrusion and the guiding protrusion are not arranged side-by-side in the peripheral direction.
With the above-described configuration, when the member-to-be-fastened-and-fixed is fixed to the resin component using the internal thread of the internal thread member, the member-to-be-fastened-and-fixed pushes the engagement arm of the internal thread member toward the first fixation surface of the component body. This causes the fitting protrusion of the engagement arm to be fitted into the fitting recess of the component body. The fitting of the fitting protrusion into the fitting recess restricts rotation in the removal direction of the internal thread member relative to the component body. Therefore, in this structure, the internal thread member is not easily removed.
The present disclosure achieves fastening and fixing of a member-to-be-fastened-and-fixed in a metal-to-metal contact state.
The present disclosure also facilitates attachment and removal of the internal thread member.
A resin component according to a first embodiment of the present disclosure will now described.
As shown in
The insert nut 30 includes a nut portion 32 and a thread main body 33. The nut portion 32 is made of a metallic material and includes an internal thread 31 at the center. The thread main body 33 is made of a synthetic resin and surrounds the entire perimeter of the nut portion 32. The nut portion 32 is a general-purpose product. Specifically, the nut portion 32 is a knurled nut that has a flange at one end 32A (the upper end as viewed in
In the insert nut 30, the end 32A of the nut portion 32 slightly protrudes from the outer surface (the upper surface as viewed in
The component body 50 of the radiator support 20 is made of a synthetic resin and shaped like a gate (cap) having a right wall, an upper wall, and a left wall. The component body 50 has multiple (ten in the present embodiment) through-holes (attachment holes 51). An insert nut 30 is inserted into and attached to each attachment hole 51. Specifically, as shown in
In a state in which the insert nut 30 is secured to the component body 50 (the state shown in
The structure of the insert nut 30 will now be described.
As shown in
The center tube 36 has four blades 37 at the end on the outer side (the upper side in
Two of the four blades 37, which are arranged on the opposite sides of the internal thread 31, each have an integrated ratchet arm 38. The ratchet arm 38 protrudes in a clockwise direction from the radially outer end of the blade 37. Specifically, the ratchet arm 38 extends in an arcuate shape of which the center is the center line L of the center tube 36. The ratchet arm 38 extends along the outer circumferential surface of the center tube 36 at a position spaced apart from the outer circumferential surface. The ratchet arm 38 includes a first end (a proximal end 38A), which is supported by the radially outer end of the blade 37, and a second end (a distal end 38B), which is a free end not supported by the blade 37. The ratchet arm 38 thus has a cantilever-like structure. The ratchet arm 38 is allowed to swing about the proximal end 38A in the direction along the center line L and the radial direction of the internal thread 31. A section of the ratchet arm 38 that includes the proximal end 38A is thinner than the distal end 38B. The ratchet arm 38 is therefore easily elastically deformed (easily swings).
The surface on the outer side (the upper side in
As shown in
The structure of the component body 50 of the radiator support 20 will now be described.
As shown in
The component body 50 has a tubular portion 55 at the end on the inner side (the right end in
The inner diameter of the attachment hole 51 is slightly greater than the outer diameter of the center tube 36 of the insert nut 30. The two engagement protrusions 52 protrude from the inner circumferential surface of the small diameter portion 54. The engagement protrusions 52 are arcuate as viewed in plan view (refer to
As shown in
As shown in
As shown in
In the present embodiment, the ratchet arms 38 (the ratchet racks 39) of the insert nut 30 and the ratchet recesses 58 (specifically, the ratchet racks 57) of the component body 50 are included in a ratchet mechanism. When the ratchet racks 39, 57 are engaged with each other, the ratchet mechanism allows the insert nut 30 to rotate clockwise in plan view relative to the component body 50, while restricting counterclockwise rotation of the insert nut 30.
As shown in
The relief recesses 59 are at positions where the engagement protrusions 40 of the ratchet arms 38 are accommodated in the relief recesses 59 in a state in which the insert nut 30 has been inserted into the attachment hole 51 but has not been rotated (the state shown in
An operation of attaching the insert nut 30 to the component body 50 will now be described together with operational advantages of the radiator support 20 of the present embodiment.
The attachment of the insert nut 30 to the component body 50 is performed by moving the insert nut 30 from the outer side toward the inner side with respect to at least one of the walls of the gate-shaped (cap-shaped) component body 50. Specifically, when the insert nut 30 is attached to the right wall of the component body 50, the insert nut 30 is moved leftward. When the insert nut 30 is attached to the upper wall of the component body 50, the insert nut 30 is moved downward. When the insert nut 30 is attached to the left wall of the component body 50, the insert nut 30 is moved rightward. The attachment of the insert nut 30 is performed using automatic apparatus with a robotic arm.
In the attachment of the insert nut 30, the robotic arm holds the end on the outer side of the insert nut 30 (the upper side in
Then, as shown in
Thereafter, the insert nut 30 is rotated clockwise in plan view. At this time, the insert nut 30 is guided by engagement between the engagement recesses 35 in the outer circumferential surface (specifically, the engagement grooves 41) and the engagement protrusions 52 on the inner surface of the attachment hole 51 of the component body 50. In the present embodiment, the surface of each engagement protrusion 52 includes a section on the inner side in the insertion direction (the contact surface 52A), and the surface defining each engagement recess 35 includes a section on the inner side (the contact surface 35A). The contact surfaces 52A and 35A both extend along an imaginary spiral plane of which the spiral axis is the center line L. Thus, when the insert nut 30 is rotated clockwise in plan view with the engagement protrusions 52 and the engagement recesses 35 engaged with each other, the contact surfaces 52A and 35A of the engagement protrusions 52 and the engagement recess 35 contact each other as in an example shown in
In the present embodiment, the insert nut 30 is secured in the attachment hole 51 of the component body 50 by increasing the surface pressure between the contact surfaces 52A and 35A of the engagement protrusions 52 and the engagement recesses 35. In this case, the high surface pressure acting on the contact surfaces 52A and 35A of the engagement protrusions 52 and the engagement recesses 35 limits chattering of the insert nut 30.
In the present embodiment, although limited within the ranges of the manufacturing tolerances, the engagement protrusions 52 of the component body 50 may be made thin or the engagement recesses 35 of the insert nut 30 may be widened. In this case, the contact surface pressure between the contact surfaces 52A of the engagement protrusions 52 and the contact surfaces 35A of the engagement recesses 35 is unlikely to increase in some cases. Thus, when the insert nut 30 is rotated clockwise in plan view with the engagement protrusions 52 and the engagement recesses 35 engaged with each other, the surface pressure between the contact surfaces 52A and 35A may fail to reach or exceed the predetermined value.
In this respect, in the present embodiment, the engagement protrusions 52 of the component body 50 abut the partition wall portions 44 of the insert nut 30 as shown in
In the present embodiment as described above, when the insert nut 30 is inserted into the attachment hole 51 of the component body 50 and rotated in the circumferential direction, the engagement protrusions 52 on the inner circumferential surface of the attachment hole 51 and the engagement recesses 35 in the outer circumferential surface of the insert nut 30 are engaged with each other. The insert nut 30 is thus attached to the component body 50. In the present embodiment, as shown in
The present embodiment includes the ratchet mechanism having the ratchet arms 38 of the insert nut 30 and the ratchet recesses 58 of the component body 50. The ratchet mechanism is structured to allow the insert nut 30 to rotate clockwise relative to the component body 50 in plan view of the insert nut 30. Thus, when the insert nut 30 is rotated clockwise in plan view (in a direction indicated by arrow R in
The ratchet mechanism is structured such that, when the ratchet arms 38 of the insert nut 30 and the ratchet recesses 58 of the component body 50 are engaged with each other, counterclockwise rotation in plan view of the insert nut 30 relative to the component body 50 is restricted. Thus, when the insert nut 30 is attached to the component body 50, the insert nut 30 is prevented from being loosened due to an undesired counterclockwise rotation after the ratchet mechanism enters an engaged state.
Further, in the present embodiment, when the insert nut 30 is attached to the component body 50, the engagement protrusions 40 of the ratchet arms 38 are accommodated in the relief recesses 49 of the large diameter portion 53 of the component body 50 as shown in
In a radiator support made of a metallic material of a first comparative example, a metal nut for fixing a frame member can be directly fixed (welded) to the radiator support. Since the metal nut does not have to be removed when the radiator support is discarded, the radiator support is easy to recycle.
In a radiator support made of a synthetic resin of a second comparative example, a metal nut cannot be directly welded to the radiator support. In the radiator supports of the comparative examples, an internal thread member (for example, a pop nut) can be fixed by swaging. These radiator supports not only need a costly tool for swaging, but also require troublesome operations when the internal thread members are removed for recycle or repair.
A nut may be arranged on the back of the radiator support of the second comparative example, which is made of a synthetic resin. The radiator support and the frame member are held between the nut and a bolt, so that the radiator support and the frame member are fixed to each other. The radiator support thus has a structure that withstands a high pull-out load. However, if an automatic apparatus is used to attach a nut to the radiator support, a robotic arm needs to enter a narrow space on the inner side of the radiator support in the engine compartment. The attachment of the nut is thus difficult.
As compared with these comparative examples, the radiator support 20 of the present embodiment allows a robotic arm of an automatic apparatus to easily attach the insert nut 30 to the radiator support 20 (the component body 50) from the outer side such that the insert nut 30 withstands a high pull-out load. Further, since the insert nut 30 can be removed from the component body 50 by being rotated counterclockwise in plan view, the radiator support 20 can be easily recycled or repaired.
As shown in
In the present embodiment, the outer surface (the upper surface in
In the present embodiment, the internal thread 31 of the insert nut 30 is a right-handed thread, and the contact surface 52A of each engagement protrusion 52 and the contact surface 35A of the corresponding engagement recess 35 extend along a spiral plane extending clockwise. Thus, the rotational force that acts on the insert nut 30 when the bolt 22 is threaded to the internal thread 31 of the insert nut 30 acts in a direction rotating the insert nut 30 in a direction increasing the surface pressure between the contact surface 52A of the engagement protrusion 52 and the contact surface 35A of the engagement recess 35. The structure therefore prevents the internal thread 31 of the insert nut 30 from being loosened when the internal thread 31 and the bolt 22 are threaded to each other.
When a force that separates the frame member 21 fixed to the radiator support 20 from the radiator support 20 is applied to the frame member 21, specifically, when a force that pulls out the insert nut 30 from the attachment hole 51 of the component body 50 is applied to the frame member 21, the component body 50 is likely to be deformed in the following manner. That is, the force (pull-out load) acts such that the contact surface 35A of each engagement recess 35 of the insert nut 30 pushes the contact surface 52A of the corresponding engagement protrusion 52 of the component body 50 toward the outer side (the upper side in
In this regard, in the present embodiment, the end (the tubular portion 55) on the leading side (the lower side in
In the present embodiment, the surface on the outer side (the upper side in
As shown in
As described above, the present embodiment provides the following advantages.
(1) The outer surface of the end 32A of the nut portion 32 of the insert nut 30 slightly protrudes with respect to the outer surface of the component body 50. The end 32A of the nut portion 32 is also exposed to the outside. Thus, the frame member 21 is fastened and fixed to the radiator support 20 in a metal-to-metal contact state, in which the frame member 21 and the end 32A of the nut portion 32 contact each other.
(2) When the insert nut 30 is attached to the component body 50, the insert nut 30 is inserted into the attachment hole 51 of the component body 50, and the insert nut 30 is rotated in the circumferential direction. This allows the engagement protrusions 52 on the inner circumferential surface of the attachment hole 51 and the engagement recesses 35 in the outer circumferential surface of the insert nut 30 to be engaged with each other, so that the insert nut 30 is secured to the component body 50.
(3) The contact surface 52A of each engagement protrusion 52 and the contact surface 35A of the corresponding engagement recess 35 have shapes that extend along an imaginary spiral plane of which the spiral axis is the center line L. When the insert nut 30 is attached to the component body 50, the insert nut 30 is rotated in the circumferential direction in a state in which the engagement protrusions 52 and the engagement recesses 35 are engaged with each other. This increases the surface pressure between the contact surfaces 52A and 35A of the engagement protrusions 52 and the engagement recesses 35, thereby limiting the insert nut 30 from chattering.
(4) One end in the circumferential direction of the engagement groove 41 of each engagement recess 35 is the partition wall portion 44, which closes the engagement recess 35. Thus, the partition wall portions 44 contacting the engagement protrusions 52 of the component body 50 prevent the insert nut 30 from being rotated excessively. Further, when the engagement protrusions 52 of the component body 50 abut the partition wall portions 44 of the insert nut 30, chattering of the insert nut 30 is limited.
(5) The radiator support 20 includes the ratchet mechanism, and the ratchet mechanism includes the ratchet arms 38, which are integrated with the insert nut 30, and the ratchet recesses 58, which are provided in the component body 50. Thus, when the insert nut 30 is attached to the component body 50, the insert nut 30 is rotated clockwise in plan view with respect to the insert nut 30. Further, after the insert nut 30 is attached to the component body 50, the ratchet mechanism prevents the insert nut 30 from being rotated counterclockwise in plan view unnecessarily and loosened.
(6) The surface on the outer side of the distal end 38B of each ratchet arm 38 extends substantially in the same plane as the outer surface of the component body 50. Thus, the outer surface of the distal end 38B of each ratchet arm 38 abuts the frame member 21 in a state in which the frame member 21 is fastened and fixed to the radiator support 20. At this time, the ratchet arm 38 is prevented from being elastically deformed toward the outer side away from the ratchet recess 58. Since this prevents the ratchet arms 38 and ratchet recesses 58 from being unnecessarily disengaged from each other, the insert nut 30 is prevented from being rotated unnecessarily and loosened.
(7) The end on the inner side of the periphery of the attachment hole 51 of the component body 50 (the tubular portion 55) has a tubular shape that protrudes such that the inner circumferential wall of the attachment hole 51 extends toward the inner side. This prevents the component body 50 from being deformed by a pull-out load, so that the radiator support 20 has a structure that withstands a high pull-out load.
The above illustrated embodiment may be modified as follows. The above-described embodiment and the following modifications can be combined as long as the combined modifications remain consistent with each other.
The insert nut 30 may have a structure in which the surface on the outer side of the thread main body 33 and the surface on the outer side of the end 32A of the nut portion 32 extend on the same plane.
The radiator support 20 may have a structure in which the surface on the outer side of the end 32A of the nut portion 32 and the surface on the outer side of the periphery of the attachment hole 51 of the component body 50 extend on the same plane.
In the structure of the insert nut 30, the surface on the outer side of the distal end 38B of each ratchet arm 38 may be located slightly toward the outer side with respect to the surface on the outer side of the thread main body 33 (specifically, the center tube 36 or the blades 37). Also, in the structure of the insert nut 30, the surface on the outer side of the distal end 38B of each ratchet arm 38 may be located slightly toward the inner side with respect to the surface on the outer side of the thread main body 33 (specifically, the center tube 36 or the blades 37).
The engagement protrusions 40 of the ratchet arms 38, and the relief recesses 59 and the accommodating recesses 60 of the component body 50 may be omitted.
The ratchet arms 38 and the ratchet recesses 58 (the ratchet racks 57) may be omitted.
Instead of providing the tubular portion 55 in a section on the inner side of the periphery of the attachment hole 51 of the component body 50, two or more wall portions that extend along the center line L may be provided about the center line L at equal intervals. Alternatively, the tubular portion 55 of the component body 50 can be omitted.
The insert nut 30 may be structured such that the two engagement recesses 35 are continuous. In this structure, the width of the engagement recess 35 is preferably reduced, or the thickness of the engagement protrusion 52 is preferably increased, so as to increase the surface pressure between the contact surface 52A of the engagement protrusion 52 and the contact surface 35A of the engagement recess 35. This structure causes rotation of the insert nut 30 to be stopped when the insert nut 30 is rotated only by a predetermined amount.
The contact surface 52A of each engagement protrusion 52 and the contact surface 35A of the corresponding engagement recess 35 do not necessarily need to have shapes that extend along a spiral plane, but may have flat shapes orthogonal to the center line L. Even in this structure, the insert nut 30 can be secured to the component body 50 by determining the shapes of the engagement protrusions 52 and the engagement recesses 35 such that the contact surface pressure between the outer surface of each engagement protrusion 52 and the inner surface of the corresponding engagement recess 35 is increased to a sufficient level.
A general-purpose nut other than a knurled nut may be used as the nut portion 32. Alternatively, a dedicated part that has been uniquely designed may be employed.
The insert nut 30 does not necessarily need to be manufactured by insert molding. Instead, an insert nut may be manufactured by preparing a thread main body and a nut portion separately, and fixing the nut portion to the thread main body, for example, by bonding.
The resin component of the above-described embodiment is not limited to the radiator support 20 made of a synthetic resin, to which the insert nut 30 is attached, but may be any resin component to which an internal thread member having a nut made of a metallic material is attached.
A resin component according to a second embodiment of the present disclosure will now described.
As shown in
The insert nut 130 includes a nut portion 132 and a thread main body 133. The nut portion 132 is made of a metallic material and includes an internal thread 131 at the center. The thread main body 133 is made of a synthetic resin and surrounds the entire perimeter of the nut portion 132. The nut portion 132 is a general-purpose product. Specifically, the nut portion 132 is a knurled nut that has a flange at one end 132A (the upper end in
In the insert nut 130, the end 132A of the nut portion 132 slightly protrudes from the outer surface (the upper surface as viewed in
The component body 150 of the radiator support 120 is made of a synthetic resin and shaped like a gate (cap) having a right wall, an upper wall, and a left wall. The component body 150 has multiple (ten in the present embodiment) through-holes (attachment holes 151). The insert nut 130 is inserted into each attachment hole 151 and attached to the component body 150. Specifically, as shown in
In a state in which the insert nut 130 is secured to the component body 150 (the state shown in
The structure of the insert nut 130 will now be described.
As shown in
The center tube 136 has four blades 137 at the end on the outer side (the upper side in
Each blade 137 includes an integrated engagement arm 138. The engagement arm 138 protrudes in a counterclockwise direction from the radially outer end of the blade 137. Specifically, the engagement arm 138 extends in an arcuate shape of which the center is the center line L of the center tube 136. The engagement arm 138 extends along the outer circumferential surface of the center tube 136 at a position spaced apart radially outward from the outer circumferential surface. The engagement arm 138 includes a first end (a proximal end 138A), which is supported by the radially outer end of the blade 137, and a second end (a distal end 138B), which is a free end not supported by the blade 137. The engagement arm 138 thus has a cantilever-like structure. The engagement arm 138 is allowed to be elastically deformed such that the distal end 138B swings about the proximal end 138A in the direction along the center line L or the radial direction of the internal thread 131.
The radially outer section at the end on the outer side (the upper side in
In the present embodiment, the section on the outer side of the insert nut 130 has a shape that is fitted inside the hexagonal recess of a hexagon socket. Specifically, when a hexagon socket is fitted to the insert nut 130 from the outer side, the inner surface of the hexagon socket pushes the inclined surfaces 138C of the engagement arms 138. Accordingly, the engagement arms 138 are elastically deformed toward the inner side of the hexagon nut until the end on the outer side of the insert nut 130 is accommodated in the hexagon socket.
The distal end 138B of each engagement arm 138 has a shape that forms one corner of the hexagonal shape. The distal end 138B has a fitting protrusion 145 on the surface on the inner side (the lower side in
The center tube 136 has the two groove-shaped engagement recesses 135, which are equally spaced apart in the peripheral direction of the center tube 136. As shown in
The structure of the component body 150 of the radiator support 120 will now be described.
As shown in
The attachment hole 151 has the two engagement protrusions 152 on the inner circumferential surface. The distal end faces of the engagement protrusions 152 are arcuate in plan view (refer to
As shown in
As shown in
The inner edge section 151A of the component body 150 has two fitting recesses 154, which are equally spaced apart in the peripheral direction of the center tube 136. Each fitting recess 154 extends in an arcuate shape of which the center is the center line L of the attachment hole 151. Each fitting recess 154 is adjacent to the guiding protrusion 153C. Specifically, the fitting recess 154 is located on the leading side of the guiding protrusion 153C in a case of a clockwise rotation in plan view. In this manner, the guiding protrusions 153C and the fitting recesses 154 are arranged in the peripheral direction of the attachment hole 151 in the present embodiment.
When the insert nut 130 is inserted into the attachment hole 151 of the component body 150 as shown in
The component body 150 includes an unlock marker protrusion 155 on the outer surface. The unlock marker protrusion 155 is located near the inner edge section 151A. Specifically, in a state in which the insert nut 130 has been inserted into the attachment hole 151 of the component body 150 but has not been rotated (the state shown in
An operation of attaching and removing the insert nut 130 to and from the component body 150 will now be described together with operational advantages of the radiator support 120 of the present embodiment.
First, an operation of attaching the insert nut 130 to the component body 150 will be described.
The attachment of the insert nut 130 to the component body 150 is performed by moving the insert nut 130 from the outer side toward the inner side with respect to the gate-shaped (cap-shaped) component body 150. Specifically, when the insert nut 130 is attached to the right wall of the component body 150, the insert nut 130 is moved leftward. When the insert nut 130 is attached to the upper wall of the component body 150, the insert nut 130 is moved downward. When the insert nut 130 is attached to the left wall of the component body 150, the insert nut 130 is moved rightward. The attachment of the insert nut 130 is performed using automatic apparatus with a robotic arm.
In this operation, the section on the outer side of the insert nut 130 is first fitted to a general-purpose hexagon socket attached to the robotic arm.
Then, as shown in
Thereafter, the insert nut 130 is rotated clockwise in plan view. At this time, the insert nut 130 is guided by engagement between the engagement recesses 135 in the outer circumferential surface (specifically, the engagement grooves 141) and the engagement protrusions 152 on the inner surface of the attachment hole 151 of the component body 150. In the present embodiment, as shown in
In the present embodiment, the insert nut 130 is secured inside the attachment hole 151 of the component body 150 by increasing the contact pressure between the contact surfaces 152A and 135A of the engagement protrusions 152 and the engagement recesses 135. Accordingly, movement in the fastening direction of the insert nut 130 relative to the component body 150 is restricted, and chattering of the insert nut 130 is limited.
In the present embodiment, although limited within the ranges of the manufacturing tolerances, the engagement protrusions 152 of the component body 150 may be made thin or the engagement recesses 135 of the insert nut 130 may be widened. In this case, the contact surface pressure between the contact surfaces 152A of the engagement protrusions 152 and the contact surfaces 135A of the engagement recesses 135 is unlikely to increase. Thus, when the insert nut 130 is rotated clockwise in plan view with the engagement protrusions 152 and the engagement recesses 135 engaged with each other, the surface pressure between the contact surfaces 152A and 135A may fail to reach or exceed the predetermined value.
In this respect, in the present embodiment, the engagement protrusions 152 of the component body 150 abut the partition wall portions 144 of the insert nut 130 when the insert nut 130 rotates a certain amount. This prevents the insert nut 130 from rotating excessively. Further, in addition to the increase in the contact pressure between the contact surfaces 152A of the engagement protrusions 152 and the contact surfaces 135A of the engagement recesses 135 (where the contact pressure<the predetermined value), the leading end in the rotation direction of each engagement protrusion 152 and the corresponding partition wall portion 144 of the insert nut 130 contact each other (abut each other). This limits chattering of the insert nut 130. Also, one of the marker recesses 139 of the insert nut 130 is aligned in the circumferential direction with the lock marker protrusion 156 of the component body 150.
In the present embodiment as described above, when the insert nut 130 is inserted into the attachment hole 151 of the component body 150 and rotated in the circumferential direction, the engagement protrusions 152 on the inner circumferential surface of the attachment hole 151 and the surfaces defining the engagement recesses 135 in the outer circumferential surface of the insert nut 130 are engaged with each other. The insert nut 130 is thus attached to the component body 150. In the present embodiment, as shown in
In the present embodiment, as shown in
As shown in
When the insert nut 130 is rotated further as shown in
Thus, once the insert nut 130 is attached to the component body 150, the fitting protrusions 145 of the engagement arms 138 and the guiding protrusions 153C of the component body 150 abut each other even if the insert nut 130 is rotated counterclockwise in plan view (in the removal direction). Since further rotation of the insert nut 130 is restricted, the insert nut 130 is prevented from being loosened.
In the present embodiment, a section of the radially inner surface of each guiding protrusion 153C is inclined such that the distance to the center line L decreases toward the leading side in the rotation direction in a case of a clockwise rotation of the insert nut 130 in plan view. It therefore simply requires rotation of the insert nut 130 relative to the component body 150 to cause the fitting protrusions 145 to pass the guiding protrusions 153C, thereby arranging each guiding protrusion 153C and the corresponding fitting protrusion 145 side-by-side in the peripheral direction.
Next, an operation of removing the insert nut 130 from the component body 150 will be described.
When removing the insert nut 130 from the component body 150, a hexagon socket is fitted to a section on the outer side (a section including the second fixation surface 130A) of the insert nut 130.
In a state in which the engagement arms 138 are not elastically deformed as shown in
However, even in a state in which the engagement arms 138 are not elastically deformed as shown in
In the operation of removing the insert nut 130 from the component body 150, the fitting protrusions 145, which are integrated with the distal ends 138B of the engagement arms 138 (refer to
In the removal operation state, the insert nut 130 can be removed from the attachment hole 151 of the component body 150 by rotating the insert nut 130 in the removal direction together with the hexagon socket.
As described above, the state in which the insert nut 130 can be rotated in the removal direction (the state shown in
In a radiator support made of a metallic material of a first comparative example, a metal nut for fixing the frame member 121 can be directly fixed (welded) to the radiator support. Since the metal nut does not have to be removed when the radiator support is discarded, the radiator support is easy to recycle.
In a radiator support made of a synthetic resin of a second comparative example, a metal nut cannot be directly welded to the radiator support. In these radiator supports, an internal thread member (for example, a blind nut) can be fixed by swaging. These radiator supports not only need a costly tool for swaging, but also require troublesome operations when the internal thread members are removed for recycle or repair.
A nut may be arranged on the back of the radiator support of the second comparative example, which is made of a synthetic resin. The radiator support and the frame member 121 are held between the nut and a bolt, so that the radiator support and the frame member 121 are fixed to each other. The radiator support thus has a structure that withstands a high pull-out load. However, if an automatic apparatus is used to attach a nut to the radiator support, a robotic arm needs to enter a narrow space on the inner side of the radiator support. The attachment of the nut is thus difficult.
The radiator support 120 of the present embodiment allows a robotic arm of an automatic apparatus to easily attach the insert nut 130 to the radiator support 120 (the component body 150) from the outer side of the radiator support 120 such that the insert nut 130 withstands a high pull-out load. Further, since the insert nut 130 can be removed from the component body 150 by being rotated with the hexagon socket fitted to the insert nut 130 from the outer side, the radiator support 120 can be easily recycled or repaired. The present embodiment facilitates attachment and removal of the insert nut 130 to and from the component body 150 from the outer side of the insert nut 130 (the side corresponding to the first fixation surface 150A), that is, from the section (location) in which a space for fixing the member-to-be-fastened-and-fixed is secured.
With the radiator support 120 of the present embodiment, attachment and removal of the insert nut 130 can be performed by a general-purpose tool, which is readily available. Such general-purpose tools include, in addition to a hexagon socket, a dodecagon socket, a ring wrench, a wrench, and an adjustable wrench. Therefore, an operator or an automatic apparatus can perform attachment or removal of the insert nut 130 not only in a manufacturing plant, which is equipped with a dedicated attaching apparatus, but also in a maintenance workshop, where maintenance of automobiles is performed, and a dismantling facility, where automobiles are dismantled.
An operation of attaching the frame member 121 (shown in
The frame member 121 is fixed to the radiator support 120 using the internal thread 131 of the insert nut 130 and a fastening-fixing bolt (not shown). Specifically, the bolt is threaded into the internal thread 131 of the insert nut 130 after being passed through the insertion hole of the frame member 121.
When the frame member 121 is not fixed to the radiator support 120 as shown in
Then, when the frame member 121 is fixed to the radiator support 120 as shown in
After the frame member 121 is fixed to the radiator support 120 in this manner, the fitting of the fitting protrusions 145 of the engagement arms 138 into the fitting recesses 154 of the component body 150 restricts rotation in the removal direction of the insert nut 130 relative to the component body 150. A structure is thus achieved in which the insert nut 130 is not easily removed.
In the present embodiment, the outer surface (the second fixation surface 130A, or the upper surface in
In the present embodiment, the internal thread 131 (
In the present embodiment, the end 147 on the inner side (the lower side in
As described above, the present embodiment provides the following advantages.
(1) The present embodiment facilitates attachment of the insert nut 130 to the component body 150 from the outer side, that is, from the section (location) in which the space for fixing the frame member 121 is secured.
(2) The insert nut 130 is brought into the condition in which the insert nut 130 can be rotated in the removal direction simply by elastically deforming the engagement arms 138 such that each fitting protrusion 145 and the corresponding guiding protrusion 153C are not arranged side-by-side in the peripheral direction. In this state, insert nut 130 can be removed from the component body 150 by rotating the insert nut 130 in the removal direction.
(3) After the frame member 121 is fixed to the radiator support 120, rotation in the removal direction of the insert nut 130 relative to the component body 150 is restricted by fitting of the fitting protrusion 145 of each engagement arm 138 into the corresponding fitting recess 154 of the component body 150. A structure is thus achieved in which the insert nut 130 is not easily removed.
(4) The insert nut 130 can be removed from the component body 150 by fitting the hexagon socket to the insert nut 130 and rotating the insert nut 130 without performing additional operation of disengaging the fitting protrusions 145 of the engagement arms 138 from the guiding protrusions 153C of the component body 150.
(5) When a hexagon socket is press-fitted to the insert nut 130 from the outer side, the inner surface of the hexagon socket pushes the inclined surfaces 138C of the engagement arms 138. Accordingly, the engagement arms 138 are elastically deformed until a section on the outer side of the insert nut 130 is fitted into the hexagon socket.
(6) A section of the radially inner surface of each guiding protrusion 153C is inclined such that the distance to the center line L decreases toward the leading side in the rotation direction in a case of a clockwise rotation in plan view. It therefore simply requires rotation of the insert nut 130 relative to the component body 150 to cause the fitting protrusions 145 to pass the guiding protrusions 153C, thereby arranging each guiding protrusion 153C and the corresponding fitting protrusion 145 side-by-side in the peripheral direction.
(7) By performing fastening and fixing by the internal thread 131 of the insert nut 130 and the bolt, the surface on the inner side of the frame member 121 and the end 132A of the nut portion 132 enter a contacting state (a metal-to-metal contact state). Accordingly, a firm fixation structure is built as the structure for fixing the frame member 121 to the radiator support 120.
The above illustrated embodiment may be modified as follows. The above-described embodiment and the following modifications can be combined as long as the combined modifications remain consistent with each other.
The shape of the section of the insert nut 130 that corresponds to the outer circumferential surface at the end on the outer side of the insert nut 130 is not limited to a substantially hexagonal shape, but may be any shape such as a square, a circle, or an ellipse. If the shape at the end on the outer side of the insert nut 130 includes two surfaces that are located on the opposite sides of the center line L and extend parallel with each other, the insert nut can be attached and removed using a general-purpose tool (such as a wrench and an adjustable wrench).
The engagement arms 138 may be configured in a manner not forming parts of the outer circumferential surface of the insert nut 130.
The surface on the outer side of the thread main body 133 of the insert nut 130 may be located slightly toward the outer side with respect to the surface on the outer side of the nut portion 132. The surface of the component body 150 to which the frame member 121 is fixed (the first fixation surface 150A) can be located slightly toward the outer side with respect to the surface of the insert nut 130, to which the frame member 121 is fixed (the second fixation surface 130A).
A section on the inner side of the outer surface of each engagement protrusion 152 of the component body 150 (the contact surface 152A) may be a surface that extends along an imaginary clockwise spiral plane of which the spiral axis is the center line L of the center tube 136 inserted into the attachment hole 151 of the component body 150. In this case, the contact surface 152A of the component body 150 and the contact surface 135A of the engagement recess 135 of the insert nut 130 preferably have the same shape. With this configuration, clockwise rotation in plan view of the insert nut 130 with the engagement protrusions 152 and the engagement recess 135 engaged with each other establish surface contact between the contact surfaces 152A of the engagement protrusions 152 and the contact surfaces 135A of the engagement recesses 135. Further rotation of the insert nut 130 increases the surface pressure between the contact surfaces 152A and 135A. The insert nut 130 is secured inside the attachment hole 151 of the component body 150 by increasing the surface pressure between the contact surfaces 152A and 135A of the engagement protrusions 152 and the engagement recesses 135. In this case, the high surface pressure acting on the contact surfaces 152A and 135A of the engagement protrusions 152 and the engagement recesses 135 limits chattering of the insert nut 130 in a favorable manner.
The contact surfaces 135A of the engagement recesses 135 of the insert nut 130 and the contact surfaces 152A of the engagement protrusions 152 of the component body 150 both may be flat surfaces orthogonal to the center line L. Even in this structure, the insert nut 130 can be secured to the component body 150 by determining the shapes of the engagement protrusions 152 and the engagement recesses 135 such that the contact surface pressure between the outer surface of each engagement protrusion 152 and the inner surface of the corresponding engagement recess 135 is increased to a sufficient level.
The structure for restricting movement in the fastening direction of the insert nut 130 relative to the component body 150 may be provided by engagement between engagement recesses in the inner surface of the attachment hole 151 of the component body 150 and engagement protrusions on the outer surface of the insert nut 130.
The structure for restricting movement in the fastening direction of the insert nut 130 relative to the component body 150 may be provided by threading between an external thread on the outer surface of the insert nut 130 and an internal thread on the inner surface of the attachment hole 151 of the component body 150.
A general-purpose nut other than a knurled nut may be used as the nut portion 132. Alternatively, a dedicated part that has been uniquely designed may be employed.
The insert nut 130 does not necessarily need to be manufactured by insert molding. Instead, an insert nut may be manufactured by preparing the thread main body 133 and the nut portion 132 separately, and fixing the nut portion 132 to the thread main body 133, for example, by bonding.
The resin component of the above-described embodiment is not limited to the radiator support 120 made of a synthetic resin, to which the insert nut 130 is attached, but may be any resin component to which an internal thread member having an internal thread is attached.
Number | Date | Country | Kind |
---|---|---|---|
2018-093094 | May 2018 | JP | national |
2018-155437 | Aug 2018 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2019/015276 | 4/8/2019 | WO | 00 |