Patent Description:
Bolts and nuts are widely used to assemble two or more parts or structures. Keeping up with the recent trend towards reduced thickness of products, bolts or nuts are pre-installed in injection molded structures. For example, a body and a cover of a battery pack are made by forming a case that is divided into two and assembling the two cases, and to easily assemble the cases, an insert nut may be press fit or pre-installed by insert molding.

Forming the injection molded part and the insert nut together by insert injection molding is advantageous in terms of assembly performance and durability, but when considering the factors such as the assembly structure of the product, the number of insert nuts required for the product and the manufacturing cost, it is better to form the injection molded part and press fitting the insert nut.

However, the press fitting of the insert nut into the injection molded structure has a high likelihood of deformation or damage of the injection molded structure when press fitting the insert nut.

<CIT> relates to the installation of screw threaded fastening means in which a nut is retained in secured relation to a body of relatively soft material by means of a basket member penetratively engaging the softer body.

<CIT> relates to fastener receivers such as nut plates, and fasteners, for example clip nut fasteners, nut cages and similar assemblies.

<CIT> relates to caged female threaded fasteners which provide high torsional strength while allowing removal of the fasteners for servicing.

<CIT> relates to a caged nut and retainer assembly for mounting a vehicle component, such as an engine cradle, to the frame or rail of a vehicle.

<CIT> relates to clip nut fasteners, nut cages and similar assemblies.

<CIT> relates to methods and apparatus for connecting a vehicle's rear suspension to the vehicle's body.

<CIT> relates to a retainer assembly for at least one fastener, for example, a nut or a bolt, in which the fastener is floatingly retained or captivated within a channel member.

For example, as shown in <FIG>, to insert the insert nut <NUM> into a nut fixing groove <NUM> of the injection molded structure <NUM>, it is necessary to forcibly stretch the dashed line section of <FIG> wide apart to place parts of the insert nut in the nut fixing groove <NUM>, then completely push the insert nut <NUM> into the nut fixing groove <NUM> by hitting with a hammer (not shown). In this process, stress is applied to a region where the insert nut is inserted, and the corresponding region is vulnerable to deformation or damage. In this case, when a bolt is screwed into the insert nut, deformation and damage of the injection molded structure becomes worse by the fastening force between the bolt and nut, resulting in degradation of the durability of the product. Additionally, the damage of the region where the insert nut is inserted is seemingly invisible, so even though the product is determined to be faulty in the durability test, in many cases, it is difficult to find the cause.

The present disclosure is designed to solve the above-described problem, and therefore the present disclosure is directed to providing an insert nut insertion structure for preventing deformation or damage of an injection molded structure by minimizing stress that may be applied to the injection molded structure when inserting an insert nut.

The present disclosure is further directed to providing an insert nut and an insert nut insertion structure for easily inserting the insert nut into an injection molded structure by hand without using a tool such as a hammer.

These and other objectives and advantages of the present disclosure can be understood by the following description, and will be apparent from the embodiments of the present disclosure. In addition, it will be readily appreciated that the objectives and advantages of the present disclosure can be realized by the means set forth in the appended claims and a combination thereof.

To achieve the above-described objective, an insert nut insertion structure of the present invention includes an insert nut including a bolt fastening portion having threads on an inner circumference into which a bolt is screwed; and a flange portion provided on an outer circumference of the bolt fastening portion and extended in a circumferential direction of the bolt fastening portion; and a nut fixing groove into which the insert nut is inserted in a first direction perpendicular to a direction in which the bolt is screwed, wherein the nut fixing groove includes a flange receiving portion having an internal space conforming to a shape of the flange portion; and a pair of fingers provided on the flange portion positioned in the flange receiving portion and formed in a cantilever shape that surrounds, in part, a periphery of the bolt fastening portion.

The flange receiving portion includes a base plate on which the flange portion is seated; two side plates which are vertically extended from the base plate and contact two sides of the flange portion; and cover plates which are horizontally extended from the two side plates, contact an upper surface of the flange portion and are spaced a predetermined distance apart from the pair of fingers.

The flange portion may be provided in contact with the cover plates and in non-contact with the pair of fingers.

The flange portion includes a lower flange portion and an upper flange portion formed in double layer along a lengthwise direction of the bolt fastening portion, the upper flange portion may be positioned in a space between the pair of fingers and the cover plates, and the lower flange portion may be positioned in a space between the cover plates and the base plate.

The lower flange portion may be provided in contact with the cover plates.

The upper flange portion may be provided in non-contact with the pair of fingers.

The bolt fastening portion may have a cylindrical shape, and the pair of fingers may be extended side by side in a contrary direction to the first direction with their facing inner surfaces being a curved surface conforming to the outer circumference of the bolt fastening portion.

The pair of fingers may be made of an elastic material to allow the fingers to return to an original state when a force exerted to stretch the fingers wide apart is removed.

A top periphery of the bolt fastening portion may be interference fit in between the pair of fingers in the first direction.

According to another aspect of the present disclosure, there is provided a battery pack case including the insert nut insertion structure.

According to the present disclosure, it is possible to prevent deformation or damage of the injection molded structure by minimizing stress that may be applied to the injection molded structure when inserting the insert nut.

Additionally, according to the present disclosure, it is possible to easily insert the insert nut into the injection molded structure by hand without using a tool such as a hammer.

The effect of the present disclosure is not limited to the above-described effects, and these and other effects will be clearly understood by those skilled in the art from the present disclosure and the accompanying drawings.

Hereinafter, the exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Prior to the description, it should be understood that the terms or words used in the specification should not be construed as being limited to general and dictionary meanings, but rather interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define the terms appropriately for the best explanation. Therefore, the embodiments described herein and the illustrations shown in the drawings are just an exemplary embodiment of the present disclosure, but not intended to fully describe the technical aspects of the present disclosure, so it should be understood that a variety of other equivalents and modifications could have been made thereto at the time that the application was filed.

<FIG> is a perspective view of an insert nut according to an embodiment of the present disclosure, <FIG> is a perspective view showing the insert nut and a nut fixing groove according to an embodiment of the present disclosure which is not in accordance with the invention, and <FIG> is a perspective view showing an assembly structure of the insert nut and the nut fixing groove of <FIG>.

As shown in these drawings, an insert nut insertion structure according to an embodiment of the present disclosure includes the insert nut <NUM> and the nut fixing groove <NUM>.

The insert nut <NUM> includes a bolt fastening portion <NUM> having threads 11a on the inner circumference into which a bolt <NUM> is screwed, and a flange portion <NUM> provided on the outer circumference of the bolt fastening portion <NUM> and extended in the circumferential direction of the bolt fastening portion <NUM>. Additionally, the nut fixing groove <NUM> may include a flange receiving portion <NUM> and a pair of fingers <NUM>, <NUM>, and may be configured to allow the insert nut <NUM> to be inserted in a first direction (Y axis direction) perpendicular to the direction in which the bolt <NUM> is screwed.

As described in detail below, the present disclosure is configured to easily stretch the pair of fingers <NUM>, <NUM> wide apart with a small force, the fingers which play a role in holding the insert nut <NUM> when the insert nut <NUM> is inserted into the nut fixing groove <NUM>, making it easy to insert the insert nut <NUM>, and to apply a fastening force exerted by the bolt <NUM> to cover plates 21d, 21e of the flange receiving portion <NUM> rather than the pair of fingers <NUM>, <NUM> when the bolt <NUM> is screwed, thereby reducing or eliminating deformation and damage risks of a case structure.

Hereinafter, the insert nut insertion structure of the present disclosure will be described in detail.

As shown in <FIG>, the bolt fastening portion <NUM> of the insert nut <NUM> according to an embodiment of the present disclosure may have a cylindrical shape having threads on the inner circumference, and the flange portion <NUM> may have a rectangular plate shape and may be disposed on the bottom of the bolt fastening portion <NUM>. Additionally, the insert nut <NUM> may include the cylindrical bolt fastening portion <NUM> protruding to a predetermined height in the Z axis direction from the center of the rectangular plate-shaped flange portion <NUM>. In particular, in this embodiment, the flange portion <NUM> has the horizontal length extended longer than the vertical length to cause the fastening force of the bolt <NUM> to act on the cover plates 21d, 21e of the flange receiving portion <NUM> as described below when the bolt <NUM> is screwed into the insert nut <NUM> afterwards.

As shown in <FIG>, which is not in accordance with the invention, the flange receiving portion <NUM> of the nut fixing groove <NUM> according to an embodiment of the present disclosure may have an internal space that conforms to the shape of the flange portion <NUM> to allow the insert nut <NUM> to be inserted, and as shown in <FIG>, the pair of fingers <NUM>, <NUM> may include the first finger <NUM> and the second finger <NUM> that are disposed on the flange portion <NUM>, and each having a cantilever shape surrounding, in part, the periphery of the bolt fastening portion <NUM>, when the flange portion <NUM> is placed in the flange receiving portion <NUM>.

The first finger <NUM> and the second finger <NUM> may be integrally formed with the upper plate of the case structure C1, and each extended side by side in a contrary direction (-Y axis direction) to the first direction (+Y axis direction), spaced such a distance apart from each other as to allow the bolt fastening portion <NUM> to be inserted, with their facing inner surfaces being a curved surface conforming to the outer circumference of the bolt fastening portion <NUM> to bring them into close contact with the outer circumference of the bolt fastening portion <NUM>.

Additionally, the pair of fingers <NUM>, <NUM> may be in a cantilever shape at predetermined distances S1,S2 away from the cover plates 21d, 21e and made of an elastic material so the first finger <NUM> and the second finger <NUM> can return to the original state after the force exerted to stretch wide apart is removed. Here, the elastic material includes plastics that can return to the original state after it is a bit deformed with a small force. The pair of fingers <NUM>, <NUM> of this embodiment are integrally formed with the case structure C1 formed by plastic injection molding, but they are invulnerable to damage caused by the small force that is exerted to stretch the fingers <NUM>, <NUM> wide open, then removed. Alternatively, the pair of fingers <NUM>, <NUM> may be made of a metal to eliminate the damage risk of the pair of fingers <NUM>, <NUM>. For example, the pair of fingers <NUM>, <NUM> may be manufactured using a metal and assembled into the case structure C1.

Since the first finger <NUM> and the second finger <NUM> having the cantilever structure are easy to stretch wide apart, it is possible to insert the bolt fastening portion <NUM> in between the first finger <NUM> and the second finger <NUM> very easily when inserting the insert nut <NUM> into the nut fixing groove <NUM>. For example, the first finger <NUM> and the second finger <NUM> may be spontaneously stretched wide apart by the bolt fastening portion <NUM> when the flange portion <NUM> is pushed into the flange receiving portion <NUM> in the first direction without needing to stretch the first finger <NUM> and the second finger <NUM> wide apart by hand, and in this condition, when the flange portion <NUM> is completely pushed into the flange receiving portion <NUM>, the first finger <NUM> and the second finger <NUM> may return to the original state and the top periphery of the bolt fastening portion <NUM> may be interference fitted in between the pair of fingers <NUM>, <NUM>.

Accordingly, the flange portion <NUM> of the insert nut <NUM> is disposed in the internal space of the flange receiving portion <NUM>, and the upper part of the bolt fastening portion <NUM> is constrained between the first finger <NUM> and the second finger <NUM>, thereby preventing the bolt fastening portion <NUM> from sliding away in the contrary direction (-Y axis direction) to the insertion direction.

Referring back to <FIG> and <FIG>, which are not in accordance with the invention, the flange receiving portion <NUM> of the nut fixing groove <NUM> according to this embodiment may include a base plate 21a on which the flange portion <NUM> is seated, two side plates 21b, 21c which are vertically extended from the base plate 21a and come into contact with the two sides of the flange portion <NUM>, and the cover plates 21d, 21e which are horizontally (±X axis direction) extended from the two side plates 21b, 21c, come into contact with the upper surface of the flange portion <NUM> and are spaced a predetermined distance apart from the pair of fingers <NUM>, <NUM>.

As shown in <FIG>, which is not in accordance with the invention, when the insert nut <NUM> of this embodiment is inserted into the nut fixing groove <NUM>, the left side of the flange portion <NUM> contacts the left side plate 21b of the flange receiving portion <NUM>, and the right side of the flange portion <NUM> contacts the right side plate 21c of the flange receiving portion <NUM>. Accordingly, the insert nut <NUM> may be restrained from rotating when the bolt <NUM> is screwed afterwards.

Additionally, the upper surfaces of the horizontal (±X axis direction) edges of the flange portion <NUM> are covered with the left cover plate 21d and the right cover plate 21e of the flange receiving portion <NUM>. Accordingly, when the bolt <NUM> is screwed afterwards, the fastening force of the bolt <NUM> and the insert nut <NUM> is applied to the left cover plate 21d and the right cover plate 21e.

In particular, the flange portion <NUM> is in contact with the cover plates 21d, 21e and in non-contact with the pair of fingers <NUM>, <NUM> when the bolt <NUM> is screwed. To this end, the cover plates 21d, 21e are thicker than the first finger <NUM> and the second finger <NUM>. Additionally, the base of the pair of fingers <NUM>, <NUM> is disposed at a higher position than the base of the cover plates 21d, 21e.

As shown in <FIG>, which is not in accordance with the invention, the case structure C1 having the insert nut insertion structure and another structure C2 may be assembled by the fastening of the bolt <NUM> and the insert nut <NUM>.

In this instance, as shown in <FIG>, which is not in accordance with the invention, due to the structure in which the left side and the right side of the flange portion <NUM> of the insert nut <NUM> contact the left side plate 21b and the right side plate 21c of the flange receiving portion <NUM>, the insert nut <NUM> is held in place when the bolt <NUM> screws into the insert nut <NUM>. Additionally, as described above, due to the structure in which the upper surfaces of the two horizontal (±X axis direction) edges of the flange portion <NUM> of the insert nut <NUM> are in contact with the left cover plate 21d and the right cover plate 21e of the flange receiving portion <NUM> and in non-contact with the first finger <NUM> and the second finger <NUM> when the bolt <NUM> is screwed, the fastening force between the bolt <NUM> and the insert nut <NUM> is only applied to the left cover plate 21d and the right cover plate 21e as indicated by the arrow in <FIG>, and is not applied to the first finger <NUM> and the second finger <NUM>. Accordingly, when the bolt <NUM> is screwed, the fastening force exerted by the bolt <NUM> hardly acts on the pair of fingers <NUM>, <NUM>, so there is no deformation or damage risk of the pair of fingers <NUM>, <NUM>.

The insert nut insertion structure according to an embodiment of the present disclosure may insert the insert nut <NUM> into the nut fixing groove <NUM> easily and rapidly without needing to apply an excessive force or use a hammer to insert the insert nut into the groove of the structure as does the conventional press fitting, and has no or little risk of deformation or damage to the nut fixing groove <NUM> when inserting the insert nut <NUM> or installing the bolt <NUM>.

<FIG> is a perspective view of an insert nut 10A according to an embodiment of the invention, <FIG> is a perspective view showing the insert nut 10A and a nut fixing groove 20A according to another embodiment of the present invention, <FIG> is a perspective view showing an assembly structure of the insert nut 10A and the nut fixing groove 20A of <FIG>, <FIG> is a diagram showing an insert nut insertion structure and another structure fastened using a bolt <NUM> according to another embodiment of the present disclosure, and <FIG> is a schematic cross-sectional view of <FIG>.

Subsequently, the insert nut insertion structure according to the invention will be described with reference to <FIG>.

The same reference numeral as the previous embodiment indicates the same element, and to avoid redundancy, the overlapping description is omitted and the following description is made based on difference(s) between this embodiment and the previous embodiment.

In the same way as the previous embodiment, a bolt fastening portion <NUM> of the insert nut 10A according to another embodiment of the present invention has a cylindrical shape having threads on the inner circumference and a flange portion <NUM> has a rectangular plate shape. However, as shown in <FIG>, when compared with the previous embodiment, the flange portion <NUM> of the insert nut 10A of another embodiment of the present disclosure includes a lower flange portion <NUM> and an upper flange portion <NUM> in double layer along the lengthwise direction (Z axis direction) of the bolt fastening portion <NUM>, the flange portion <NUM> has a shorter horizontal length, and the bolt fastening portion <NUM> is extended longer. Additionally, the nut fixing groove 20A according to another embodiment of the present disclosure includes a flange receiving portion <NUM> and a pair of fingers <NUM>, <NUM> to allow the insertion of the insert nut 10A.

In another embodiment of the present disclosure, it is possible to easily insert the insert nut 10A into the nut fixing groove 20A and prevent the fastening force of the bolt <NUM> from being applied to the first finger <NUM> and the second finger <NUM> when the bolt <NUM> is screwed afterwards in the same way as the previous embodiment, and to increase the fastening strength due to the long bolt <NUM> having a larger length than the previous embodiment screwing into the insert nut 10A and reduce the horizontal width of the nut fixing groove 20A.

Additionally, as shown in <FIG>, when compared with the flange receiving portion <NUM> of the previous embodiment, the flange receiving portion <NUM> according to another embodiment of the present disclosure includes the base plate 21a that is smaller in horizontal width and the two side plates 21b, 21c that are longer in the Z axis direction. Additionally, the cover plates 21d, 21e are extended in the horizontal direction (±X axis direction) at the mid-position of the two side plates 21b, 21C.

Additionally the pair of fingers <NUM>, <NUM> may be provided with substantially the same structure as the previous embodiment at the location of the same level as the topmost height of the two side plates 21b, 21c. That is, in another embodiment of the present disclosure, the cover plates 21d, 21e are present under the pair of fingers <NUM>, <NUM>.

When the insert nut 10A is inserted into the nut fixing groove 20A, as shown in <FIG>, the upper part of the bolt fastening portion <NUM> is interference fitted in between the first finger <NUM> and the second finger <NUM>, the upper flange portion <NUM> of the insert nut <NUM> is positioned in a space between the pair of fingers <NUM>, <NUM> and the cover plates 21d, 21e, and the lower flange portion <NUM> of the insert nut <NUM> is positioned in a space between the cover plates 21d, 21e and the base plate 21a.

Additionally, as shown in <FIG>, the case structure C1 including the insert nut 10A insertion structure of the invention and another structure C2 may be assembled by the bolting <NUM>.

In this instance, as shown in <FIG>, due to the structure in which the lower flange portion <NUM> of the insert nut 10A is in contact with the cover plates 21d, 21e and the upper flange portion <NUM> is in non-contact with the pair of fingers <NUM>, <NUM> when the bolt <NUM> is screwed, the fastening force between the bolt <NUM> and the insert nut 10A is only applied to the left cover plate 21d and the right cover plate 21e as indicated by the arrow in <FIG> and is not applied to the first finger <NUM> and the second finger <NUM>. Accordingly, the fastening force exerted by the bolt <NUM> hardly acts on the pair of fingers <NUM>, <NUM>, thereby preventing deformation or damage of the pair of fingers <NUM>, <NUM>.

Meanwhile, a battery pack case according to the present disclosure includes the insert nut insertion structure. Here, the battery pack case may be configured to receive at least one battery cell and various types of devices used to control the charge/discharge of the battery cells, for example, electrical equipment such as a battery management system (BMS) current sensor and a fuse.

Claim 1:
An insert nut (10A) insertion structure, comprising:
an insert nut (10A) including a bolt fastening portion (<NUM>) having threads (11a) on an inner circumference into which a bolt (<NUM>) is screwed; and a flange portion (<NUM>) provided on an outer circumference of the bolt fastening portion (<NUM>) and extended in a circumferential direction of the bolt fastening portion (<NUM>); and
a nut fixing groove (20A) into which the insert nut (10A) is inserted in a first direction perpendicular to a direction in which the bolt (<NUM>) is screwed,
wherein the nut fixing groove (20A) includes:
a flange receiving portion (20A) having an internal space conforming to a shape of the flange portion (<NUM>); and
a pair of fingers (<NUM>, <NUM>) provided on the flange portion (<NUM>) positioned in the flange receiving portion (20A) and formed in a cantilever shape that surrounds, in part, a periphery of the bolt fastening portion (<NUM>), wherein the flange receiving portion (20A) includes:
a base plate (21a) on which the flange portion (<NUM>) is seated;
two side plates (21b, 21c) which are vertically extended from the base plate (21a) and contact two sides of the flange portion (<NUM>); and
cover plates (21d, 21e) which are horizontally extended from the two side plates (21b, 21c), contact an upper surface of the flange portion (<NUM>) and are spaced a predetermined distance apart from the pair of fingers (<NUM>, <NUM>), characterized in that
the flange portion (<NUM>) includes a lower flange portion (<NUM>) and an upper flange portion (<NUM>) formed in double layer along a lengthwise direction of the bolt fastening portion (<NUM>),
wherein the upper flange portion (<NUM>) is positioned in a space between the pair of fingers (<NUM>, <NUM>) and the cover plates (21d, 21e), and
wherein the lower flange portion (<NUM>) is positioned in a space between the cover plates (21d, 21e) and the base plate (21a).