JP2011241911A - Tapping nut and mounting part structure thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tapping nut capable of smoothly releasing coupling of two members and separating the two members from each other that are made of materials not having enough mechanical strength such as a fiber reinforced resin.SOLUTION: The tapping nut 40 includes a male screw for tapping formed on the outer circumference and a female screw 42 for engaging with a bolt formed on the inner circumference, wherein the tapping nut is embedded in a base material 10. The tip surface 43 of the nut is formed of a rotation control shape for cutting into the base material 10 with rotation in tapping and regulating rotation in the reverse direction of rotation in tapping.

Description

  The present invention relates to a tapping nut that is embedded and used in advance in a base material, and in particular, a tapping nut that is suitable for use in a battery case coupling portion for storing a battery that serves as a power source for a driving motor of an electric vehicle. And a tapping nut mounting portion structure.

When a lid is fixed to the opening of a container, a bolt or nut is embedded in the container side in advance, and the lid is covered with the opening of the container, and the nut or bolt is embedded in the bolt or nut embedded so as to sandwich the attachment part of the lid. Fasten and fix. When the buried bolt or the buried nut is used, the mounting workability is greatly improved as compared with the case where both the bolt and the nut are used in a free state.
For example, in the case of a battery case for storing a battery that serves as a power source for a motor for driving an electric vehicle, as described in Patent Document 1, for example, a large number of embedded holes are formed in the outer periphery of a tray corresponding to a container. Bolt holes are formed in the outer periphery of the cover corresponding to the lid so as to correspond to the respective embedded holes, and the battery is stored in this tray, and embedded bolts or embedded nuts are embedded in the embedded holes, and the cover is covered. Then, the nut or the bolt is fastened to the embedded bolt or the embedded nut, and the cover is fixed to the tray.

  In the case of a battery case, the tray and cover are generally made of fiber reinforced resin, and the fiber reinforced resin does not have sufficient mechanical strength as a base material to embed the nut, and the thread strength is increased even if the screw is cut directly. We cannot secure enough. Thus, for example, it is conceivable to use an insert nut [also referred to as an embedded nut or an insert nut (trade name)] that enters the round hole while tapping, as described in Patent Document 2 and the like. That is, a large number of embedding round holes smaller in diameter than the outer diameter of the insert nut are machined at intervals in the outer periphery of the tray, and the insert nut is inserted and buried while tapping.

  However, when performing maintenance or replacement of the battery stored in the tray, it is necessary to remove all the bolts screwed into the insert nut and remove the cover from the tray. However, when the bolt is removed, the insert nut may rotate together and the insert nut may come off the round hole for embedding the tray. The material of the tray is insufficient in mechanical strength, so even if it is tapped again, sufficient thread will not be cut and once it comes off, the same or the same diameter insert nut will be embedded with sufficient strength again. It becomes difficult.

In addition, there exists a thing described in patent document 3 etc. as a technique which prevents the co-rotation which arises when removing a volt | bolt from a nut.
Patent Document 3 discloses a height adjustment bolt (male on the outer periphery) in which a female screw hole is formed in the center of the head in order to adjust the height of a cast iron piano frame to a wooden support assembly. A technique is described in which a screw is not an insert nut but a wood screw) and is used by being screwed into a column assembly so that the head protrudes. In this technology, the piano frame is placed on the head of the height adjustment bolt, and the fixing bolt is inserted into the screw hole of the piano frame formed corresponding to the female screw hole of the height adjustment bolt head. Then, the piano frame is fixed between the head of the fixing bolt and the head of the height adjusting bolt by screwing and fastening into the female screw hole of the height adjusting bolt. A rotation stopper that prevents the height adjustment bolt from co-rotating when the fixing bolt is removed is formed around the female screw hole on the top surface of the head of the height adjustment bolt (paragraph 0024). This detent is made up of a number of teeth formed so as to be continuous in the circumferential direction of the upper surface of the head of the height adjustment bolt that bites into the piano frame when the fixing bolt is fastened, and the height adjustment bolt loosens. When trying to rotate in a direction, a large number of teeth further bite into the lower surface of the piano frame, preventing the height adjustment bolts from co-rotating.

JP 2009-87645 A Japanese Patent No. 4395465 JP 2001-75555 A

By the way, in the case of a battery case, it is necessary to maintain the environment in the case in a state favorable for the battery. For this purpose, when fixing the cover to the tray, the battery case should be joined without any gaps. It is required to block the inside from the outside as much as possible.
From such a viewpoint, as shown in FIG. 6, a structure for fixing the cover 102 to the tray 101 in the battery case 100 can be considered. In this fixing structure, a material having insufficient mechanical strength, such as fiber reinforced resin, is applied to the tray 101 and the cover 102 which are base materials for fixing the nuts. It is assumed that an insert nut 103 that is effective for fixing is embedded in the outer peripheral edge portion 101 </ b> A of the tray 101. 6 shows only one section of the tray outer peripheral edge 101A of the tray 101, the tray outer peripheral edge 101A of the tray 101 is similarly provided with a number of insert nuts 103 at predetermined intervals in the extending direction. Buried. Further, a split groove 103a for removing cutting waste of the base material generated by tapping is formed on the tip end side of the insert nut 103.

  As shown in FIG. 6, a gasket is interposed between the tray 101 and the cover 102 inside the embedded portion of the insert nut 103 to seal between the two. The fixing bolt 104 is fastened to the insert nut 103 with the cover outer peripheral edge 102A of the cover 102 and the plate 105 interposed therebetween. In particular, the plate 105 is made of metal and extends in the extending direction of each tray outer peripheral edge portion 101 </ b> A and the cover outer peripheral edge portion 102 </ b> A. The plate 105 is connected to each tray outer peripheral edge by the insert nut 103 and the fixing bolt 104. The fastening that is intermittently performed in the extending direction of the portion 101A and the outer peripheral edge portion 102A of the cover is made continuous, and the tray 101 and the cover are formed without gaps over the entire circumference of the outer peripheral edge portion 101A and the outer peripheral edge portion 102A of the cover. 102.

  In such a configuration, when the female nut of the insert nut 103 and the male screw of the fixing bolt 104 are fixed, if the insert nut 103 rotates together when the fixing bolt 104 is removed, the insert nut 103 is Although it rises together with the fixing bolt 104, the rise is restricted by the plate 105, and the fixing bolt 104 and the insert nut 103 rotate together without being lifted while idling and scrape the screw surface of the tray 101 formed by tapping. As a result, the insert nut 103 and the fixing bolt 104 cannot be reused.

  Therefore, although it is necessary to prevent the insert nut 103 from rotating, the insert nut 103 does not have a head like the height adjustment bolt disclosed in Patent Document 3, and therefore cannot be provided with a head. Further, since there is no member corresponding to the piano frame sandwiched between the height adjustment bolt and the fixing bolt in Patent Document 3 between the insert nut 103 and the fixing bolt 104, a fastening force is used. It is also impossible to make a detent. Furthermore, in the case of a material that does not have sufficient mechanical strength, such as fiber reinforced resin, there is a possibility that the material strength may not be obtained if it is sandwiched by a pressing force in the axial direction to bite the non-rotating blade.

  The present invention was devised in view of such a problem, and is configured to reliably connect two members such as a battery case tray and a cover, which are composed of materials having insufficient mechanical strength such as fiber reinforced resin. It is an object of the present invention to provide a tapping nut and a tapping nut mounting portion structure that can be coupled to each other and that can be separated without any problem to separate both members.

  In order to achieve the above object, a tapping nut of the present invention has a tapping male screw formed on the outer periphery and a bolt screwing female screw formed on the inner periphery, and is embedded in the base material. Rotation restriction that is a nut and that bites into the base material together with the rotation at the time of tapping on the nut tip surface (end surface on the tip side that enters the base material at tapping), and restricts rotation in the direction opposite to the rotation direction at tapping It is characterized by a shape.

The rotation restricting shape includes a first inclined surface that is inclined forward with respect to the rotation direction at the time of tapping, and a second inclined surface that is inclined backward with respect to the rotation direction at the time of tapping larger than the inclination angle of the first inclined surface, or It is preferable that the vertical surface along the axial direction is constituted by annular uneven surfaces that are alternately continuous.
The tapping nut is preferably a plastic mold type tapping nut that plastically deforms the tray at the time of tapping and threads the base material without producing cutting waste from the base material.

In the tapping nut mounting portion structure of the present invention, the base material to which the tapping nut is attached by tapping is formed using a plastically deformable material, and the base material is used for the tapping nut. It is preferable that a cylindrical round hole having an inner diameter that is intermediate between the outer diameter of the male thread crest and the outer diameter of the trough is formed.
The base material is a tray made of fiber reinforced resin constituting a battery case of an electric vehicle, and the bolt screwed into the female screw for screwing of the tapping nut constitutes the battery case on the tray. Preferably, the cover to be sealed is joined.

According to the tapping nut of the present invention, the tapping nut itself can be embedded while tapping (threading of the female screw) with the male screw for tapping, and the female screw for embedding the nut is provided. A nut can be embedded without tapping the base material in advance.
Further, when removing the bolts screwed to the female screw for screwing such a tapping nut, the tapping nut may rotate together as the tapping nut and the bolt are fixed and rotated in the direction of loosening the bolt. However, the rotation restricting shape that restricts the rotation in the direction opposite to the rotation direction at the time of tapping provided on the nut tip surface bites into the base material and prevents the tapping nut from rotating together, and the tapping nut is embedded Only the bolt can be removed while maintaining the state.

  If a plastic mold type tapping nut is used as the tapping nut, the tray can be plastically deformed at the time of tapping, and can be threaded to the base material without generating cutting waste from the base material. Processing such as a split groove for eliminating debris is not required, and a rotation restricting shape can be formed on the entire tip of the tapping nut, thereby enhancing the effect of restricting the rotation.

According to the tapping nut mounting portion structure of the present invention, the base material is formed using a plastically deformable material, and the base material includes an outer diameter of a crest of the tapping nut tapping male screw and an outer portion of the trough. Since the cylindrical round hole which has an internal diameter of a magnitude | size intermediate | middle with a diameter is formed, it can thread to a base material, without taking out cutting waste from a base material.
When the cover is hermetically bonded to the tray made of fiber reinforced resin that constitutes the battery case of an electric vehicle, the fiber reinforced resin that requires insulation can secure the insulation required for the battery case, but the mechanical strength is sufficient If you try to embed a nut with a male screw on the outer periphery after tapping the tray in advance and removing the tapping tool, the female screw formed on the resin material of the tray when removing the tapping tool Will be deformed and the subsequent screwing of the nut cannot be performed reliably. In this regard, if the present tapping nut is used, the tapping nut can be reliably embedded, and the tapping nut is securely locked to the tray.

  In addition, since the rotation restricting shape is formed on the tip surface of the tapping nut, when the tapping nut is tapped, if the tip surface of the tapping nut comes into contact with the bottom of the hole on the base material (tray) side, The rotation restricting shape of the tip surface of the tapping nut bites into the bottom of the hole while sliding on the bottom of the hole as the tapping nut rotates. Since the base material tray is made of fiber reinforced resin, if the bite is slid in contact with the bottom of the hole in the base material in this way, the resin is generated by the heat generated by the slidable contact due to the thermoplasticity that is a general resin characteristic. It softens and plastically deforms to help bite into the rotation-restricted shape, and input of excessive mechanical force to the hole of the tray can be suppressed. After that, the resin temperature is lowered to normal temperature and solidified, and the state in which the rotation restricting shape has bite into the bottom of the hole is maintained.

  Therefore, this rotation restricting shape prevents the tapping nut from rotating together with the bolt when loosening the bolt screwed on the female screw of the tapping nut, and the tapping nut is securely held in the tray. The bolt is screwed into the female screw of the tapping nut again, the tray is interposed between the bolt and the tapping nut, and the cover is hermetically bonded to the tray even if the bolt is screwed into the female screw of the tapping nut. be able to. Thereby, maintainability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the tapping nut concerning one Embodiment of this invention, (a) is principal part sectional drawing which shows the attaching part structure of a tapping nut (AA arrow cross section of the state which assembled the battery case shown in FIG. (B) is a front view of the tip side of the tapping nut. It is a disassembled perspective view which shows the battery case of the electric vehicle concerning one Embodiment of this invention. It is the perspective view which shows the tapping nut concerning one Embodiment of this invention, (a) is the perspective view which looked at the tapping nut from the base end side, (b) is the perspective view which looked at the tapping nut from the front end side, (c) ) Is a longitudinal sectional view for explaining the rotation restricting shape of the tapping nut (a sectional view taken along the line BB in FIG. 4A), and (d) is a longitudinal sectional view for explaining a modification of the rotation restricting shape of the tapping nut. is there. It is a figure which shows the tapping nut concerning one Embodiment of this invention, (a) is a front view of a front end surface, (b) is a side view (left half part) and longitudinal cross-sectional view (right half part) of a tapping nut. is there. It is a longitudinal cross-sectional view corresponding to FIG.3 (c) explaining the effect | action of the rotation control shape of the tapping nut concerning one Embodiment of this invention (however, upside down direction), (a) is a rotation control shape of a base material. A longitudinal sectional view showing a state in contact with the bottom of the hole, (b) is a longitudinal sectional view showing an embedded state in which the rotation restricting shape bites into the bottom of the hole of the base material, and (c) is a rotation restricting shape rotating. It is a longitudinal cross-sectional view which shows the state to regulate. It is sectional drawing which shows the attachment part structure of the tapping nut concerning the subject of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a tapping nut and its mounting structure according to an embodiment of the present invention. FIGS. 1A and 1B are sectional views showing the mounting structure and the tip side of the tapping nut. FIG. 2 is an exploded perspective view showing a battery case of an electric vehicle equipped with the mounting portion structure, and FIGS. 3A to 3D are perspective views showing the tapping nut and a longitudinal sectional view of a rotation restricting shape. 4 (a) and 4 (b) are a front view and a sectional view showing the tapping nut, and FIGS. 5 (a) to 5 (c) are longitudinal sectional views showing an annular section of the tip surface of the tapping nut.

[Constitution]
(Battery case)
First, a battery case of an electric vehicle to which the tapping nut attachment structure according to this embodiment is applied will be described.

As shown in FIG. 2, the battery case 1 includes a tray 10 located on the lower side and a cover 20 located on the upper side.
The tray 10 and the cover 20 are formed of a fiber reinforced resin having electrical insulation. For example, fibers such as glass fiber and carbon fiber can be used as the reinforcing fiber. However, in this embodiment, the fiber is less elastic and has a lower elasticity than the carbon fiber because it is difficult to resonate with vehicle vibration and the material cost can be easily suppressed. Priced glass fiber is used. The matrix resin is a general thermoplastic resin.

Further, in the present embodiment, the tray 10 is located below the cover 20 and houses a battery (not shown) to support the weight thereof. Therefore, the tray 10 has a higher glass fiber content than the cover 20 and is more rigid. It has a high strength material composition.
The tray 10 has a pair of front and rear front walls 11a and rear walls 11b, a pair of right and left right and left walls 11c and 11d, and a bottom wall 11e. The tray 10 has a box shape with an open upper surface facing the bottom wall 11e. Is formed. Here, the front and rear and the left and right correspond to the direction of the vehicle body (not shown), the front wall 11a is on the front side of the vehicle body, the rear wall 11b is on the rear side of the vehicle body, the right side wall 11c is on the right side of the vehicle body, and the left side wall 11d. Are located on the left side of the vehicle body. Further, the peripheral wall 11 of the tray 10 is configured by the front wall 11a, the rear wall 11b, the right side wall 11c, and the left side wall 11d.

  The inside of such a box-shaped tray 10 is partitioned by a partition wall 11f. The partition wall 11f includes a plurality of partitions parallel to the front wall 11a and the rear wall 11b, and a plurality of partitions parallel to the right side wall 11c and the left side wall 11d. The battery compartment 18 is divided into a part 18 and an equipment storage part 19 for storing equipments such as electric circuits other than the battery. Yes.

The battery module (not shown) is, for example, a battery in which a plurality of cells made of lithium ion batteries are connected in series, and a plurality of or a single cell is stored in each of the battery storage sections 18 divided into a plurality of parts. 11e.
A thickened cover mounting surface 12 is continuously formed on the peripheral wall 11 of the tray 10 without a gap over the entire circumference.

  As shown in FIG. 1A, a groove (annular groove) 13 for accommodating the gasket 14 is formed on the entire surface of the cover mounting surface 12, and the nut 13 is embedded outside the groove 13. A plurality of holes 15 are formed over the entire circumference at predetermined intervals in the direction in which the cover mounting surface 12 extends. Each hole portion 15 is a round hole having a cylindrical peripheral surface, and a bottom portion 16 is partially provided with a concave portion 17 for storing a cutting waste of a base material at a central portion. A number of holes 15 for embedding nuts are provided over the entire circumference of the cover mounting surface 12 at relatively short intervals in order to strengthen the coupling between the tray 10 and the cover 20.

On the other hand, as shown in FIGS. 1A and 2, the cover 20 has a service plug opening 25 and a cooling air inlet 26 formed at the front thereof. Further, on the upper surface of the cover 20, a bypass flow path portion 29 for allowing a part of the cooling air to flow, a cooling fan housing portion 30 and the like are provided.
A flange portion 21 is continuously formed on the peripheral edge of the cover 20 over the entire periphery of the peripheral edge of the cover 20. The flange portion 21 has a flange upper surface portion 21a and a flange lower surface portion 21b. The flange lower surface portion 21 b is attached to face the cover attachment surface 12 of the tray 10. The flange portion 21 is provided with a hole portion 22 through which a bolt 50 described later passes. A plurality of the hole portions 22 are also provided over the entire circumference of the flange portion 21 at predetermined intervals corresponding to the hole portions 15 of the cover mounting surface 12.

(Tapping nut mounting part structure)
Next, the tapping nut attachment structure according to this embodiment will be described.
As shown in FIG. 1A, the tapping nut 40 has a mounting portion structure in which a nut embedding hole 15 formed in the cover mounting surface 12 on the upper surface of the peripheral wall 11 of the tray 10 and a flange portion 21 of the cover 20 are provided. The formed bolt insertion hole 22, a tapping nut 40 embedded in the hole 15, and a bolt 50 screwed into the tapping nut 40 are configured. In the case of this embodiment, the plate 60 is interposed between the bolt head 50 a of the bolt 50 and the flange portion 21 of the cover 20. Further, the tip end face 43 of the tapping nut 40 shown in FIG. 1B is embedded facing the bottom 16 of the hole 15.

  The nut-embedding hole 15 is intermediate between the outer diameter of the crest (thread 41a) of the male screw 41 and the outer diameter of the trough (flat part 41b) of the tapping nut 40 shown in FIG. The inner diameter r of the size is formed. Further, the depth of the hole 15 is formed to be approximately the same as the axial length of the tapping nut 40. That is, the nut upper surface 44 and the cover mounting surface 12 are set so as to be located on the same plane in a state where the tapping nut 40 is embedded in the hole portion 15.

The inner diameter r of the hole 22 for bolt insertion and the inner diameter r of the hole 61 of the plate 60 are also formed to the same inner diameter r as the hole 15.
Details of the tapping nut 40 will be described later.
A bolt head portion 50 a on one end side of the bolt 50 is formed with a bolt flange portion 52 having a flange-like diameter enlarged at the lower surface edge portion, and a bolt male screw portion 51 is formed on the other end side of the bolt 50. . And between the bolt head 50a of the bolt 50 and the bolt male screw part 51, the male screw has an outer diameter larger than the outer periphery of the bolt male screw part 51 and smaller than the outer diameter of the bolt flange part 52. A bolt intermediate portion 53 that is not standing is provided. The axial length of the bolt intermediate portion 53 is shorter than the total thickness of the flange portion 21 and the plate 60 by a minute amount (by a manufacturing error).

  The plate 60 is made of metal, and a plurality of holes 61 through which the bolts 50 pass are provided at predetermined intervals so as to correspond to the nut embedding holes 15 and the bolt insertion holes 22. It has a length that continues to the location. Most simply, a structure is provided in which one plate 60 is provided for each upper surface (cover mounting surface 12) of the front wall 11a, the rear wall 11b, the right side wall 11c, and the left side wall 11d constituting the peripheral wall 11 of the tray 10. Become. In this case, the length of the plate 60 is set in correspondence with the length of extension of the walls 11a to 11d. And even in the place where the fastening force of the bolt 50 is not directly applied, the plate 60 indirectly applies the fastening force of the bolt 50, extending in the longitudinal direction over the entire circumference of the flange portion 21, and having no gap. Intervened.

The hole 15 formed in the cover mounting surface 12 of the tray 10, the hole 22 provided in the flange 21 formed in the peripheral edge of the cover 20, and the hole 61 provided in the plate 60 correspond to each other. A plurality is provided at the position.
In the groove 13 formed on the cover mounting surface 12 of the tray 10, a gasket 14 that is deformed by pressurization and hermetically seals between the tray 10 and the cover 20 is accommodated.

Here, a state where the cover 20 is hermetically coupled to the tray 10 will be described.
The flange lower surface portion 21b faces the cover mounting surface 12, and the gasket interposed between the cover mounting surface 12 and the flange lower surface portion 21b is compressed and deformed to ensure the airtightness of the tray 10 and the cover 20.
The bolt male screw portion 51 is screwed into a female screw 42 formed on the inner periphery of the tapping nut 40. The bolt flange 52 is fastened with the flange 21 sandwiched between the cover mounting surface 12 via the plate 60. Thus, the cover 20 is hermetically bonded to the tray 10.

(Tapping nut)
Here, the structure of the tapping nut will be described.
As shown in FIG. 3A, a metal tapping nut 40 includes a tapping male screw 41 formed on the outer periphery, a bolt screwing female screw 42 formed on the inner periphery, and one of the female screws 42. A notch portion 45 formed by cutting out the portion, and a nut upper surface 44 that forms the upper surface of the tapping nut 40. Here, the tapping nut 40 is a screw plastic molding die that plastically deforms the resin of the tray 10 at the time of tapping and performs threading without generating cutting waste. In addition, let the nut lower side (the side which becomes a front-end | tip at the time of tapping) shown to Fig.3 (a) be a front end side, and the nut upper surface 44 side shown to Fig.3 (a) shall be a base end side.

  Further, as shown in FIG. 3B, the lower surface of the tapping nut 40 has a distal end surface 43 that is the distal end side that enters the base material during tapping. The tip surface 43 is formed with a knurled shape as a rotation restricting shape that bites into the base material along with the tapping rotation and restricts the rotation in the direction opposite to the tapping rotation direction. As shown in FIG. 3 (c), this knurl shape has an inclined surface 43a inclined forward with respect to the tapping rotation direction (arrow C) and a vertical surface 43b along the axial direction (arrow D). It is comprised by the cyclic | annular uneven surface continuous.

In addition, as shown in FIG.3 (d), it replaces with the vertical surface 43b along the axial direction of this knurl shape, and the inclination angle (theta) larger than the inclination angle ((theta) ₁ ) of the inclined surface (1st inclined surface) 43a ( A second inclined surface 43c inclined backward by θ ₂ ) may be provided. The vertical surface 43b is the most effective as a rotation control effect. However, even if the second inclined surface 43c is inclined rearward, if the inclination angle is sufficiently larger than the inclination of the inclined surface 43a, the necessary rotation control is required. The effect is obtained. The inclined surface 43a, the vertical surface 43b, or the second inclined surface 43c is the simplest plane, but may be formed as a curved surface.

  The male screw 41 is a tap for tapping the hole 15 of the tray 10 and is formed as a guide for embedding the tapping nut 40 itself. Further, as shown in FIG. 4B, the male screw 41 has a flat portion 41b formed between the screw thread 41a and the screw thread 41a, and the angle of the tip of the screw thread 41a is equal to the screw thread of a normal nut. It is formed smaller than the tip angle. Further, the thread 41a on the tip surface 43 side of the tapping nut 40 is formed small.

The notch 45 formed in the female screw 42 is a part to which a tool for rotating the tapping nut 40 is engaged when the tapping nut 40 is embedded. Here, the base end surface of the nut 40 (FIG. 3 ( A notch 45 is formed from a nut upper surface 44) in a) to a predetermined depth at which the head of the hexagon wrench can be engaged.
In this example, the cutout portion 45 is formed by removing a part of the female screw 42, and therefore the female screw 42 portion is also used as the screw at the base end portion of the nut 40 where the cutout portion 45 is formed. The function is left.

[Action / Effect]
Since the tapping nut and its attachment structure according to one embodiment of the present invention are configured as described above, the following operations and effects are achieved.

First, the embedding of the tapping nut 40 in the tray 10 will be described.
The tapping nut 40 is tapped into the hole 15 formed by the male screw portion 41 in the hole portion 15 formed in the cover mounting surface 12 so that the tip end surface 43 of the tapping nut 40 faces the bottom portion 16, and the tapping nut 40 itself. Is rotated in a direction toward the inside of the peripheral wall 11 toward the bottom 16. In order to rotate the tapping nut 40, a tool such as a hexagon wrench is engaged with the notch 45 from the base end side, and the tool is rotated to rotate the tapping nut 40.

  The hole portion 15 for embedding the nut is formed in an inner diameter r having an intermediate size between the outer diameter of the crest (thread 41a) of the male screw 41 of the tapping nut 40 and the outer diameter of the trough (flat portion 41b). Has been. For this reason, the crest of this male screw 41 can be threaded into the hole. Further, since the tapping nut 40 is a screw plastic molding die, the periphery of the threaded portion of the hole 15 is softened due to the thermoplasticity of the material of the tray 10 due to frictional heat during threading, and the flat portion of the bolt 40 is softened. The base material is processed into a screw shape without entering cutting space from the material of the tray 10 which is the base material by entering the space between the base material 41b. For this reason, engagement with the tapping nut 40 by the thread of the tapped hole 15 can be ensured.

  At this time, the tip end face 43 of the tapping nut 40 enters the material of the tray 10 as a base material as shown in FIG. The left and right arrows on the paper surface in FIG. 5 indicate the rotation direction of the tapping nut 40, and the downward arrows on the paper surface indicate the direction of entering the peripheral wall 11 when the tapping nut 40 is tapped. FIG. 5A shows a state where the tip end surface 43 of the tapping nut 40 is in contact with the bottom portion 16. As shown in FIG. 5 (b), when the tapping nut 40 is further rotated from the state of FIG. 5 (a) in the direction of entering the inside of the peripheral wall 11, the protruding portion formed by the inclined surface 43a and the vertical surface 43b. (For example, P1) and the peripheral edge thereof are in sliding contact with the bottom portion 16 to generate frictional heat due to friction. Due to the thermoplasticity of the material of the tray 10, the bottom 16 is softened and plastically deformed. The knurl shape of the distal end surface 43 enters the bottom portion 16 while plastically deforming the bottom portion 16 as the tapping nut 40 rotates. If the tapping nut 40 is rotated with an appropriate torque, the tip end surface 43 enters the bottom portion 16 with the bottom portion 16 as shown in FIG.

  Here, when a force that rotates the tapping nut 40 acts in the direction of the arrow in FIG. 5C, that is, the tapping nut 40 is in a direction opposite to the direction in which the hole 15 is tapped. When a force that rotates in the direction opposite to the direction in which the 40 itself enters the peripheral wall 11 toward the bottom acts, the deformed bottom 16 acts on the vertical surface 43b with a reaction force substantially opposite to the rotating force. As a result, the rotation of the tapping nut 40 is suppressed, and the state of being bitten into the bottom portion 16 is maintained.

Therefore, even when the bolt 50 is removed from the tapping nut 40, the state in which the tapping nut 40 is embedded can be reliably held to prevent co-rotation.
Furthermore, the following effects can also be obtained.
The tray 10 and the cover 20 are formed of a fiber reinforced resin having electrical insulation, so that the battery can be accommodated while ensuring electrical insulation from the outside, and resonance is suppressed against vehicle vibration. However, it is possible to ensure the confidentiality by appropriately following the twist of the vehicle body and deforming it.

The tapping nut 40 is formed so that the thread 41a on the distal end surface 43 side of the male screw 41 is small. For this reason, it is easy to introduce the male screw portion 41 for tapping the base material into the hole portion 15, and the effect that the screw thread 41 a can be straightened on the wall portion perpendicular to the bottom portion 16 of the hole portion 15 is also obtained.
Further, the hole portion 15 for burying the nut, the hole portion 22 for inserting the bolt, and the hole 61 of the plate 60 are respectively provided at locations corresponding to the tapping nut 40 and formed with the same inner diameter. 50 can be screwed onto the tapping nut 40. On the other hand, the axial length of the bolt intermediate portion 53 is shorter than the combined thickness of the flange portion 21 and the plate 60 by a minute amount (by a manufacturing error), and the depth of the hole portion 15 is the tapping nut. 40, when the bolt 50 is fastened to the tapping nut 40 with the cover 20 and the plate 60 interposed between the tray 10 and the bolt intermediate portion 53. The lower end surface (entrance side end surface) can be disposed at a position where the rise of the nut upper surface 44 of the tapping nut 40 can be restricted. Further, even when the bolt 50 is fastened to the tapping nut 40 that is intermittently disposed, even if the bolt 50 is fastened with a predetermined torque or more, the lower end surface of the bolt intermediate portion 53 is restricted by the nut upper surface 44 and is constant. The bolt 50 does not enter the tapping nut 40 beyond the depth of. Accordingly, the flange 21 and the cover mounting surface are uniformly adhered over the entire circumference without fastening with a biased force to a part of the mounting portion structure of the tapping nut 40 disposed at a predetermined interval. The tray 10 and the cover 20 can be sealed and joined uniformly.

  The male screw 41 has a flat portion 41b formed between the screw thread 41a and the screw thread 41a, and the angle of the tip of the screw thread 41a is smaller than the angle of the tip of the screw thread of a normal nut. Yes. That is, the thread 41a is formed to be sharper than the tip of the normal thread. For this reason, the male screw 41 at the time of tapping is easily cut into the base material, resistance to rotation at the time of tapping is reduced, and tapping can be performed satisfactorily.

The tapping nut 40 can be rotated by engaging the general tool with the notch 45. Further, the tapping nut 40 can be embedded without requiring a special tool for this rotation and without requiring a part only for this engagement.
Further, since the cutout portion 45 is formed to a predetermined depth by cutting out a part of the female screw 42, the length of the female screw 42 that is engaged when the bolt 50 is screwed can be compensated, and the tapping nut 40 is surely provided. And the bolt 50 can be fastened.

  The plate 60 is made of metal and is interposed between the bolt flange portion 52 and the flange portion 21. For this reason, the plate 60 can not only indirectly apply the fastening force of the bolt 50 even in a place where the fastening force of the bolt 50 is not directly applied, and the metal bolt flange portion 52 is provided on the resinous flange portion 21. It is possible to prevent indentation (sinking of the seating surface) and to stabilize the seating surface. Further, the plate 60 is provided with a plurality of holes 61 through which the bolts 50 pass at predetermined intervals, and extends in the longitudinal direction over the entire circumference of the flange portion 21 without a gap. For this reason, airtightness can be secured without dispersing the pressure applied to the flange portion 21 by the bolt flange portion 52 when the bolt 50 and the tapping nut 40 are fastened. That is, unlike the case where only the washer is provided in each of the intermittently provided mounting portions, the fastening torque between the tapping nut 40 and the bolt 50 is not biased by providing the plate 60 and distributing the pressure in the longitudinal direction. Cover 20 can be tightly coupled to tray 10.

The bottom 16 of the hole 15 is partially provided with a recess 17 for storing the cutting waste of the tray 10 at the center. For this reason, even if the cutting waste of the tray 10 cut by the tapping of the male screw portion 41 is generated, the cutting waste enters the concave portion and does not accumulate on the bottom portion 16, thereby hindering the tapping nut 40. It can be buried without.
A thickened cover mounting surface 12 is continuously formed on the peripheral wall 11 of the tray 10 without a gap over the entire circumference. For this reason, since the surrounding wall 11 of the intensity | strength required for accommodating a battery is partially thickened, the weight increase of the tray 10 can be suppressed. Further, by providing a width perpendicular to the longitudinal direction of the cover mounting surface due to this thickening, the degree of freedom in designing the buried portion of the tapping nut 40 is increased, and the groove portion 13 for accommodating the gasket 14 can be formed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
The material of the tray 10 and the cover 20 may not be thermoplastic as long as it is plastic. For example, even if the reaction liquid that plastically reacts with the matrix resin is applied to the male screw 41 and the tip surface 43 of the tapping nut 40 and the tapping nut 40 is embedded, the same operation and effect as described above can be obtained. .

When the cover mounting surface 12 is built up and thickened, a fiber reinforced resin different from the tray 10 may be used. For example, a resin having thermoplasticity may be used for the cover mounting surface 12, or a resin that plastically reacts with chemicals may be used.
You may have a screw thread from which the fastening direction of the male screw 41 for tapping formed in the outer periphery and the female screw 42 for bolt screwing formed in the inner periphery differs. In this case, the following operations and effects are achieved.

  The embedding of the tapping nut 40 is the same as in the embodiment. When the bolt 50 is screwed onto the tapping nut 40 and screwed together, in the case of this different thread direction, the tapping nut 40 itself is placed in a direction opposite to the direction of tapping the tapping nut 40 into the hole 15. A force that rotates in the direction opposite to the direction of entering the inside of the peripheral wall 11 toward the bottom works. However, the deformed bottom portion 16 acts on the vertical surface 43b or the second inclined surface 43c with a reaction force substantially opposite to the rotating force, thereby suppressing the rotation of the tapping nut 40. Thereby, the latching state of the tapping nut 40 to the tray 10 is reliably maintained.

  When the bolt 50 is removed, according to the configuration of the screw threads in the different directions, the tapping nut 40 rotating in the rotating direction in which the bolt 50 is removed is the direction in which the tapping nut 40 enters the inside of the peripheral wall 11. Therefore, even when the female screw of the insert nut 103 and the male screw of the fixing bolt 104 are firmly fixed, the locked state of the tapping nut 40 to the tray 10 is reliably maintained. In addition, since the inclined surface 43a and the vertical surface 43b or the second inclined surface 43c, which is the rotation restricting shape of the front end surface 43, are configured by annular concavo-convex surfaces that are alternately continuous, an excessive machine in the hole 15 of the tray 10 Input can be suppressed.

  The groove 13 formed in the cover mounting surface 12 and containing the gasket 14 may be omitted. Instead, a planar shape interposed between the cover 20 and the cover mounting surface 12 may be used.

  The present invention can be applied to machines, facilities, and apparatuses having various fastening portions because a nut can be embedded in a material having low mechanical strength and a bolt can be fastened.

DESCRIPTION OF SYMBOLS 1 Battery case 10 Tray 11 Perimeter wall 12 Cover mounting surface 14 Gasket 15 Hole part 16 Bottom part 18 Battery storage part 20 Cover 21 Flange part 21b Flange lower surface part 22 Hole part 40 Tapping nut 41 Male screw 41a Screw thread 41b Flat part 42 Female screw 43 Front end surface 43a Inclined surface 43b Vertical surface 45 Notch portion 50 Bolt 51 Bolt male screw portion 53 Bolt intermediate portion 60 Plate

Claims (5)

A tapping nut having a male screw for tapping formed on the outer periphery and a female screw for bolt screwing formed on the inner periphery, embedded in the base material,
A tapping nut characterized in that a rotation restricting shape is formed on the tip end surface of the nut so as to bite into the base material together with the rotation at the time of tapping and restrict the rotation in the direction opposite to the rotation direction at the time of tapping. The rotation restricting shape includes a first inclined surface that is inclined forward with respect to the rotation direction at the time of tapping, and a second inclined surface that is inclined backward with respect to the rotation direction at the time of tapping larger than the inclination angle of the first inclined surface, or The tapping nut according to claim 1, wherein the tapping nut is configured by annular uneven surfaces that are alternately continuous with longitudinal surfaces along the axial direction. The tapping nut is a plastic mold type tapping nut that plastically deforms the tray at the time of tapping to thread the base material without generating cutting waste from the base material. The tapping nut described. The base material to which the tapping nut according to claim 3 is attached by tapping is formed using a plastically deformable material,
The base material is formed with a cylindrical round hole having an inner diameter that is intermediate between the outer diameter of the crest of the tapping male screw of the tapping nut and the outer diameter of the trough. A tapping nut mounting part structure. The base material is a tray made of fiber reinforced resin constituting a battery case of an electric vehicle,
5. The tapping nut mounting portion structure according to claim 4, wherein a bolt that is screwed into the female screw for screwing the tapping nut is hermetically coupled to the tray with a cover that constitutes the battery case. .

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