Nut press fit arrangement

Abstract

A nut press fit arrangement (1) comprises a housing (10) with a press fit recess (20) into which a nut (130) can be pressed, the press fit recess (20) having an inner wall surface (22) and a press fit rib (30). The first rib (31) is provided on the front side in the press fit direction (Z) with respect to the second rib (32), and the projection (L1) of the inner wall surface (22) is smaller than the projection (L2) of the inner wall surface (22) of the second rib (32). The second rib (32) is provided on the rear side in the press fit direction (Z) with respect to the first rib (31), and the projection (L2) of the inner wall surface (22) is larger than the projection (L1) of the inner wall surface (22) of the first rib (31).

Description

Background of the invention 1. Field of the invention The present invention relates to a nut press fit arrangement. 2. Description of the related technology For example, JP 2021 - 114 441 A discloses an electrical connecting component comprising a nut, a housing with a press-fit groove (press-fit recess) into which the nut is pressed, and a rib formed on an inner surface of the press-fit recess and in press contact with the nut. In the nut press-fit arrangement described above in JP 2021 - 114 441 A, which is applied to electrical connection components, there is a possibility that the position of the nut may shift before the nut comes into contact with the rib in the press-fit recess at the time of press-fitting, so there is still a need for improvement with regard to processability. Summary of the invention The present invention was developed in view of the above circumstances and one objective is to provide a nut press fit arrangement which is able to improve the processability at the time of press fitting of a nut. To achieve the above-mentioned objective, a nut press-fit arrangement according to one aspect of the present invention comprises a housing with a press-fit recess into which a nut can be press-fitted along a press-fit direction, wherein the press-fit recess comprises: an inner wall surface raised along the press-fit direction, and a press-fit rib formed on the inner wall surface along the press-fit direction, which is arranged between the press-fitted nut and the inner wall surface; wherein the press-fit rib comprises a first rib and a second rib; wherein the first rib is provided on the front face of the second rib in the press-fit direction and is configured such that a projection amount from the inner wall surface is less than a projection amount from the inner wall surface of the second rib;and the second rib is provided in the press-fit direction with respect to the first rib on a back side and is designed such that a projection amount from the inner wall surface is greater than a projection amount from the inner wall surface of the first rib. The above and other objectives, features, advantages and the technical and industrial significance of this invention will be better understood by reading the following detailed description of the currently preferred embodiments of the invention when considered in conjunction with the accompanying drawings. Brief description of the drawings Fig. 1 is an exploded view showing a schematic configuration of a terminal block to which a nut press fit arrangement according to the present embodiment is applied; Fig. 2 is a perspective view schematically illustrating the nut press fit arrangement according to the present embodiment; Fig. 3 is an enlarged view of a press fit rib shown in Fig. 2; Fig. 4 is a top view schematically illustrating the nut press fit arrangement according to the present embodiment; and Fig. 5 is an enlarged view of the press fit rib shown in Fig. 4. Detailed description of preferred embodiments An embodiment of the present invention is described in detail below with reference to the drawings. It should be noted that the present invention is not limited to this embodiment. Furthermore, the components of the following embodiment include those that can be easily replaced by those skilled in the art or that are essentially the same. embodiment As shown in Fig. 1, a nut press-fit arrangement 1 according to the present embodiment is applied to a conductor fixing section 110 of a terminal block 100. The terminal block 100 described herein is, for example, mounted in a vehicle, such as an automobile, and provides the electrical connection between devices, such as a motor and an inverter. Furthermore, the conductor fixing section 110 is a section in which a conductor element 120 is arranged adjacent to a nut 130 press-fitted into a housing 10, and a section in which the conductor element 120 and a connecting counterpart element (not shown) conductively connected to the conductor element 120 are fixed by a bolt (not shown) and the nut 130. The conductor element 120 is a conductive element and is, for example, a busbar made of a metal material in plate form. The conductor element 120 is designed with a bolt insertion hole 121 through which a shaft section of a bolt to be fastened to the nut 130 is inserted. Both the bolt (not shown) and the nut 130 are conductive elements and fastening elements made, for example, of a metal material. As shown in Fig. 1 and the like, the nut 130 of the present embodiment is a square nut and, viewed in the thickness direction, is formed in a substantially rectangular shape. A bolt fastening hole 131 is formed in the nut 130. The nut 130 can fasten the conductor element 120 and the connecting counterpart element, which are sandwiched between the nut and the bolt, by securing the shank section of the bolt in the bolt fastening hole 131. It should be noted that the terminal block 100 shown in Fig. 1 has three sets of cable fixing sections 110, and the nut press-fit arrangement 1 is provided in each of the three cable fixing sections 110. Furthermore, in the nut press-fit arrangement 1, the nut 130 described above is pressed into a press-fit recess 20 formed in the housing 10. A press-fit rib 30 is provided in the press-fit recess 20 along the direction of the press fit to retain the pressed-fit nut 130.In such a configuration, the nut press fit arrangement 1 of the present embodiment achieves a configuration in which the workability at the time of press fitting of the nut 130 can be improved by configuring the press fit rib 30 provided in the press fit recess 20 by two ribs of different sizes, namely a small first rib 31, which is located on the front side in the press fit direction, and a large second rib 32, which is located on the back side in the press fit direction. Each configuration of the nut press fit arrangement 1 is described in detail below with reference to Figures 1, 2, 3, 4 to 5, and the like. It should be noted that Fig. 1 is an exploded view visualizing the position of the nut press fit assembly 1 applied to the conductor fixing section 110 of the terminal block 100 by showing a state in which only one conductor element 120 is removed. In the following description, a first, second, and third direction, which intersect each other, are referred to as the first direction "X", the second direction "Y", and the third direction "Z". Here, the first direction X, the second direction Y, and the direction Z are orthogonal to each other. Furthermore, the first direction X typically corresponds to a depth direction of the terminal block 100, an extension direction of the conductor element 120, and so on. The second direction Y corresponds to a width direction of the terminal block 100, a width direction of the conductor element 120, and so on.The press fit direction Z corresponds to a height direction of the terminal block 100, a thickness direction of the conductor element 120, a press fit direction of the nut 130 with respect to the press fit recess 20, an extension direction of the press fit rib 30 provided in the press fit recess 20, a fastening direction of a bolt with respect to the nut 130 pressed into the press fit recess 20, and the like. Furthermore, unless otherwise specified, each direction used in the following description represents a direction in a state where the individual parts are assembled together. As shown in Fig. 1 and Fig. 2, the nut press fit arrangement 1 comprises the housing 10 with a press fit recess 20 into which the nut 130 can be press fitted along the press fit direction Z. The housing 10 is an element, for example made of a plastic material with insulating properties, that holds the nut 130 received in the press-fit recess 20. As shown in Fig. 1, the housing 10 of the present embodiment is configured by combining a plurality of elements and comprises a main housing body 11, which is attached to a mounting object, and a front bracket 12 for holding the conductor element 120, which is conductively connected to the connecting counterpart element by virtue of its mounting on the main housing body 11. The press-fit recess 20 is provided in the front bracket 12, and three press-fit recesses 20 are formed on the upper surface of the front bracket 12 (the surface on the side opposite the side on which the housing body 11 is located).Here, the three press-fit recesses 20 are arranged side by side at intervals along the second width direction Y. As shown in Fig. 2, the press-fit recess 20 comprises a bottom surface 21, an inner wall surface 22, and an opening 23. The bottom surface 21 is a substantially rectangular wall surface extending along the first width direction X and the second width direction Y, and is a wall surface oriented such that it faces the opening 23 along the press-fit direction Z. Furthermore, the inner wall surface 22 is a substantially rectangular wall surface extending along the press-fit direction Z from each side of the bottom surface 21. The opening 23 is formed by being surrounded by an edge section of the inner wall surface 22 (an edge section located on one side opposite the bottom surface 21 in the press-fit direction Z) and is sized to accommodate the nut 130.The inner wall surface 22 of the present embodiment rises along the press-fit direction Z from four sides of the base surface 21, which is substantially rectangular. Therefore, in the present embodiment, four inner wall surfaces 22 are provided, and these four inner wall surfaces 22 are arranged in a rectangular frame shape when viewed from the press-fit direction Z. Of the four inner wall surfaces 22, two extend along the first width direction X and the press-fit direction Z and are arranged such that they face each other in the second width direction Y. The remaining two inner wall surfaces 22 extend along the second width direction Y and the press-fit direction Z and are arranged such that they face each other in the first width direction X. Furthermore, the opening 23 is formed in a substantially rectangular shape by the edge sections of the four inner wall surfaces 22.Therefore, the press-fit recess 20 of the present embodiment is formed as a substantially rectangular, column-shaped recess space section through the bottom surface 21, the four inner wall surfaces 22 and the opening 23. Additionally, the press fit recess 20, as shown in Figs. 2 and 3, includes a press fit rib 30 that extends linearly along the press fit direction Z on the inner wall surface 22. Two press fit ribs 30 are formed on each of the four inner wall surfaces 22 that form the press fit recess 20 (see Fig. 4). That is, eight press fit ribs 30 are provided in each press fit recess 20, and of these eight press fit ribs 30, the four press fit ribs 30 that are provided on a pair of inner wall surfaces 22 extending in the first width direction X from the press fit direction Z are arranged such that they face each other in the second width direction Y.Furthermore, the four press-fit ribs 30, which are provided on a pair of inner wall surfaces 22 extending in the second width direction Y from the press-fit direction Z, are arranged such that they face each other in the first width direction X. Each of the eight press-fit ribs 30 is located between the nut 130, which is press-fitted into the press-fit recess 20, and the inner wall surface 22 (see Fig. 4 and Fig. 5). As shown in Figs. 2 and 3, the press-fit rib 30 of the present embodiment comprises a first rib 31 and a second rib 32. The press-fit rib 30 is designed as one rib in that the first rib 31 and the second rib 32 are continuous along the press-fit direction Z. As shown in Figures 2 and 3, the first rib 31 is provided in the press fit direction Z, i.e., on the side of the opening 23, in front of the second rib 32. The first rib 31 is formed from an edge section of the inner wall surface 22 forming the opening 23 in the direction of the press fit direction Z. The first rib 31 is designed such that it projects from the inner wall surface 22 in the direction of the inner side of the press fit recess 20 and projects along the direction that intersects the inner wall surface 22. Furthermore, the first rib 31, as shown in Fig. 3 and Fig. 5, has a triangular cross-sectional shape when viewed from the press fit direction Z and comprises a pair of inclined surfaces 31a formed by a flat surface and a vertex 31b located between the pair of inclined surfaces 31a. Furthermore, as shown in Fig. 3, the first rib 31 is configured such that a projection L1 from the inner wall surface 22 in a state prior to the nut 130 being pressed into the press fit recess 20 is less than a projection L2 from the inner wall surface 22 of the second rib 32. Also, as shown in Fig. 3, the first rib 31 is configured such that a width W1 along a direction intersecting the press fit direction Z is less than a width W2 along a direction intersecting the press fit direction Z of the second rib 32. Therefore, the first rib 31 is configured to have a relatively small cross-sectional shape when viewed from the press fit direction Z compared to the second rib 32. On the other hand, as shown in Figs. 2 and 3, the second rib 32 is located on the back side in the press fit direction Z, i.e., on the underside 21 with respect to the first rib 31. The second rib 32 is designed to project from the inner wall surface 22 in the direction of the inner side of the press fit recess 20 and along the direction that intersects the inner wall surface 22. Furthermore, the second rib 31, as shown in Fig. 3, has a substantially triangular cross-sectional shape when viewed from the press fit direction Z and comprises a pair of inclined surfaces 32a formed by a flat surface and an upper surface 32b located between the pair of inclined surfaces 32a and formed from a curved surface. Furthermore, as described above, the second rib 32 is designed such that a projection L2 from the inner wall surface 22, in the state before the nut 130 is pressed into the press-fit recess 20, is larger than a projection L1 from the inner wall surface 22 of the first rib 31. The width W2 of the second rib 32 along the direction intersecting the press-fit direction Z is larger than the width W1 of the first rib 31 along the same direction. Therefore, the second rib 32 is designed to have a relatively large cross-sectional shape when viewed from the press-fit direction Z compared to the first rib 31. Furthermore, as shown in Fig. 5, the projection L1 of the first rib 31, which is designed as described above, is set such that the apex 31b of the first rib 31 comes into contact with an outer surface 130S of the nut 130 when the nut 130 is pressed into the press-fit recess 20 (see Fig. 5). In other words, with the projection L1 of the first rib 31, the distance between the pair of first ribs 31 facing each other along the first width direction X (or the second width direction Y) is set such that it is substantially equal to the width of the nut 130 along the first width direction X (or the second width direction Y).Therefore, the first rib 31 of the present embodiment can act as a guide rib that corrects the position of the nut 130 in order to hold the nut 130, which is pressed into the press-fit recess 20, in a suitable position in the press-fit recess 20. Furthermore, as shown in Fig. 5, the projection L2 of the second rib 32 is set such that the upper side 32b of the second rib 32 is worn away by the nut 130 by coming into press contact with the outer surface 130S of the nut 130 when the nut 130 is pressed into the press-fit recess 20. In other words, with the projection L2 of the second rib 32, the distance between the pair of second ribs 32 facing each other along the first width direction X (or the second width direction Y) is set such that it is substantially less than the width of the nut 130 along the first width direction X (or the second width direction Y).Therefore, the second rib 32 of the present embodiment can function as a compression rib, which is plastically deformed and worn away by the nut 130 while guiding the nut 130, which is pressed into the press-fit recess 20, along the press-fit direction Z. Furthermore, the second rib 32 can function as a press rib, which generates a frictional force to hold the nut 130, which is pressed into the innermost depth of the press-fit recess 20, in the press-fit recess 20. The above-described press-fit arrangement 1 for the nut comprises the housing 10 with the press-fit recess 20 into which the nut 130 can be pressed along the press-fit direction Z, wherein the press-fit recess 20 has an inner wall surface 22 raised along the press-fit direction Z and the press-fit rib 30, which is formed along the press-fit direction Z on the inner wall surface 22 and is arranged between the press-fit nut 130 and the inner wall surface 22, and the press-fit rib 30 comprises a first rib 31 and a second rib 32.Furthermore, the first rib 31 is provided in the press fit direction Z with respect to the second rib 32 on the front side, and the projection L1 from the inner wall surface 22 is smaller than the projection L2 from the inner wall surface 22 of the second rib 32, and the second rib 32 is provided in the press fit direction Z with respect to the first rib 31 on the back side, and the projection L2 from the inner wall surface 22 is larger than the projection L1 from the inner wall surface 22 of the first rib 31. According to such a configuration, in the nut press fit arrangement 1, at the time of press fit of the nut 130 into the press fit recess 20, the nut 130 initially comes into contact with the first rib 31 with a small projection, so that the nut 130 can be easily pressed in and its position can be corrected by the first rib 31. In the nut press fit arrangement 1, the nut 130 is pressed further back into a state in which its position is corrected by the first rib 31 and the nut 130 comes into contact with the second rib 32 with a large projection, so that the nut 130 can actually be pressed into the press fit recess 20 at a suitable position.Therefore, in the nut press fit arrangement 1 of the present embodiment, the positional displacement of the nut 130 that occurs at the time of press fit can be suppressed by providing the first rib 31 in front of the second rib 32. Therefore, the nut press fit arrangement 1 of the present embodiment can improve the processability at the time of press fit of the nut 130. Furthermore, since the position of the nut 130 can be corrected by the first rib 31 in the nut press fit arrangement 1, no separate device for correcting the position of the nut 130 is required. For example, the nut 130 can be pressed into a suitable position in the press fit recess 20 by pressing it in as is, after the worker has temporarily inserted it manually into the press fit recess 20. Therefore, the nut press fit arrangement 1 of the present embodiment can reduce the labor required when pressing the nut 130 into place and simplify the workflow, thereby further improving processability. Furthermore, in the press-fit rib 30 described above, the first rib 31 and the second rib 32 are formed continuously along the press-fit direction Z. Since the first rib 31 and the second rib 32 are connected and formed, the nut 130 can be pressed more smoothly into the press-fit recess 20 in the nut press-fit arrangement 1 according to this configuration. Therefore, the nut press-fit arrangement 1 of the present embodiment can further suppress the positional displacement of the nut 130 that occurs at the time of the press fit. Therefore, the nut press-fit arrangement 1 of the present embodiment can further improve the machinability at the time of the press fit of the nut 130. Furthermore, in the first rib 31 described above, the width W1 along the direction intersecting the press fit direction Z is smaller than the width W2 along the direction intersecting the press fit direction Z of the second rib 32, and in the second rib 32, the width W2 along the direction intersecting the press fit direction Z is larger than the width W1 along the direction intersecting the press fit direction Z of the first rib 31. Since the projection L1 and width W1 of the first rib 31 are smaller than the projection L2 and width W2 of the second rib 32, according to such a configuration in the nut press fit arrangement 1, the nut 130 can be press-fitted and held with less force.Furthermore, since in the nut press fit arrangement 1 the projection L2 and the width W2 of the second rib 32 are larger than the projection L1 and the width W1 of the first rib 31, the nut 130 can be press-fitted with greater force and held with greater force. Therefore, in the nut press fit arrangement 1 of the present embodiment, the positional displacement of the nut 130 after the actual press fit can be further suppressed by the second rib 32. Therefore, the nut press fit arrangement 1 of the present embodiment can further improve the machinability at the time of the press fit of the nut 130. Furthermore, the inner wall surface 22 described above, viewed from the press-fit direction Z, is arranged in a rectangular frame shape, and the press-fit rib 30 is provided on each of the mutually facing inner wall surfaces 22. Since the mutually facing press-fit ribs 30 are arranged such that they sandwich-like enclose the nut 130, the nut 130 can be pressed into the press-fit recess 20 in a stable position according to this configuration. Therefore, the nut press-fit arrangement 1 of the present embodiment can further suppress the positional displacement of the nut 130 that occurs at the time of the press fit. Therefore, the nut press-fit arrangement 1 of the present embodiment can further improve the machinability at the time of the press fit of the nut 130. It should be noted that the nut press fit arrangement 1 is not limited to the embodiment described above and various modifications can be made within the scope described in the claims. For example, in the description above, the nut press-fit arrangement 1 was described as being applied to the terminal block 100, but it can also be applied to an arrangement (e.g. an electrical junction box) that transmits the electrical connection between devices mounted in a vehicle. Furthermore, the first rib 31 and the second rib 32 can be formed at intervals along the press fit direction Z. Furthermore, the positions of the first rib 31 and the second rib 32 need not be aligned with respect to the width direction (in the present embodiment the first width direction X or the second width direction Y) of the inner wall surface 22, and the first rib and the second rib may be formed in positions that are offset with respect to the width direction. The shapes of the first rib 31 and the second rib 32 are not limited to the shape shown in Fig. 3 and the like. The width W1 of the first rib 31 can be smaller than the width W2 of the second rib 32. Furthermore, the shape of the press-fit recess 20, viewed from the press-fit direction Z, is not particularly restricted and can be determined according to the shape of the nut 130, which is to be press-fitted into the press-fit recess 20. The number of press-fit ribs 30 provided on the inner wall surface 22 of the press-fit recess 20 and the position of the press-fit rib 30 are not particularly limited. The above description explained that the housing 10 is formed by the combination of two elements, the housing body 11 and the front bracket 12, and that the press-fit recess 20 is provided in the housing body 11, but the housing 10 can also be formed from a single element, and the press-fit recess 20 can be provided in this element. Furthermore, the nut press fit arrangement 1 according to the present embodiment can be configured by the appropriate combination of the components of the embodiment described above. A nut press fit arrangement according to the present embodiment has the effect that the processability at the time of press fitting of the nut can be improved. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature JP 2021 - 114 441 A [0002, 0003]

Claims

A nut press fit arrangement (1) comprising: a housing (10) with a press fit recess (20) into which a nut (130) can be pressed along a press fit direction (Z), the press fit recess (20) comprising: an inner wall surface (22) raised along the press fit direction (Z) and a press fit rib (30) formed on the inner wall surface (22) along the press fit direction (Z), which is arranged between the press-fitted nut (130) and the inner wall surface (22); the press fit rib (30) comprising a first rib (31) and a second rib (32);the first rib (31) is provided in the press fit direction (Z) on a front side of the second rib (32) and is configured such that a projection amount (L1) from the inner wall surface (22) is less than a projection amount (L2) from the inner wall surface (22) of the second rib (32), and the second rib (32) is provided in the press fit direction (Z) with respect to the first rib (31) on the back side, and is configured such that a projection amount (L2) from the inner wall surface (22) is greater than a projection amount (L1) from the inner wall surface (22) of the first rib (31). The nut press fit arrangement (1) according to claim 1, wherein in the press fit rib (30) the first rib (31) and the second rib (32) are formed continuously along the press fit direction (Z). The nut press fit arrangement (1) according to claim 1 or 2, wherein the first rib (31) is formed in a width (W1) along a direction that intersects the press fit direction (Z) which is less than a width (W2) of the second rib (32) along a direction that intersects the press fit direction (Z); and the second rib (32) is formed in a width (W2) along a direction that intersects the press fit direction (Z) which is greater than a width of the first rib (31) along a direction (W1) that intersects the press fit direction (Z). The nut press fit arrangement (1) according to claim 1 or 2, wherein the inner wall surface (22) is arranged in a rectangular frame shape when viewed from the press fit direction (Z); and the press fit rib (30) is provided on each of the mutually facing inner wall surfaces (22).

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