Bolt assembly

Abstract

This invention discloses a bolt assembly that can reduce the risk of electric shock to workers during and after bolt fastening, and that can be fitted with a simple structure to prevent accidental contact with fingers. [Solution] The bolt assembly 10 comprises a bolt fitting 20 having a screw shaft portion 16 and a screw head 18 provided on one end of the screw shaft portion 16, and an insulating finger-proof cap 24 formed separately from the bolt fitting 20 and detachably assembled to the screw head 18 to cover the outer surface 22 of the screw head 18. The screw head 18 has an engaging shaft portion 46 that protrudes in the axial direction of the screw shaft portion 16 and away from the screw shaft portion 16, and the finger-proof cap 24 has a recess 66 into which the engaging shaft portion 46 is fitted. Relative rotation between the finger-proof cap 24 and the screw head 18 is prevented by engaging a portion 52 provided on one of the outer circumferential surface 49 of the engaging shaft portion 46 and the inner circumferential surface 68 of the recess 66 with an engaged portion 70 provided on the other.

Description

[Technical Field]

[0001] The present disclosure relates to a bolt assembly. [Background Art]

[0002] Patent Document 1 discloses, as one type of electrical connection structure adopted in automobiles, a structure in which a terminal provided at an end of a wire harness is bolted to a terminal provided on an electrical unit side by a fastening bolt. With such a structure, connection between terminals in a vehicle can be easily and firmly realized.

[0003] By the way, along with the increase in current of in-vehicle devices in recent years, when connecting terminals, in order to avoid the risk of electric shock to workers and the like, it has become necessary to implement various finger contact prevention measures for preventing contact of workers' fingers with portions that can become live parts. In the structure of Patent Document 1, a structure is proposed in which a working opening that exposes the head of a fastening bolt fastening terminals to the outside is covered with a cap having a sealing function. [Prior Art Literature] [Patent Literature]

[0004] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2015-130300 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, in the structure of Patent Document 1, after performing the bolt fastening work between terminals, it is necessary to cover the working opening with a separate cap, which complicates parts management and increases the number of assembly steps. Furthermore, when bolting terminals together, the fastening bolt may become a live part, so further countermeasures have been required.

[0006] Therefore, we disclose a bolt assembly that can reduce the risk of electric shock to workers during and after bolt fastening, and that can be fitted with a simple structure to prevent accidental contact with the bolts. [Means for solving the problem]

[0007] The bolt assembly of this disclosure comprises a bolt fitting having a screw shaft portion and a screw head provided on one end of the screw shaft portion, and an insulating finger-proof cap formed separately from the bolt fitting and detachably assembled to the screw head to cover the outer surface of the screw head, wherein the screw head has an engaging shaft portion that protrudes in the axial direction of the screw shaft portion in a direction away from the screw shaft portion, and the finger-proof cap has a recess into which the engaging shaft portion is fitted, and relative rotation between the finger-proof cap and the screw head is prevented by engaging portions provided on one of the outer circumferential surface of the engaging shaft portion and the inner circumferential surface of the recess engaging with a receiving portion provided on the other. [Effects of the Invention]

[0008] The bolt assembly described herein reduces the risk of electric shock to workers during and after bolt fastening, and allows for the implementation of finger-prevention measures with a simple structure. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view showing the state in which the first terminal and the second terminal are fastened together using the bolt assembly according to Embodiment 1. [Figure 2] Figure 2 is a plan view of the bolt assembly shown in Figure 1. [Figure 3] Figure 3 is a longitudinal cross-sectional view showing an enlarged view of the III-III section in Figure 2. [Figure 4] Figure 4 is a longitudinal cross-sectional view showing an enlarged view of the IV-IV section in Figure 2. [Figure 5] Figure 5 is a cross-sectional view of the VV section in Figure 3. [Figure 6] Figure 6 is a perspective view showing the bolt assembly shown in Figure 1 before fastening. [Figure 7] Figure 7 is an exploded perspective view of the bolt assembly shown in Figure 1. [Figure 8] Figure 8 is a bottom view of the finger-proof cap that constitutes the bolt assembly shown in Figure 1. [Modes for carrying out the invention]

[0010] <Description of Embodiments in this Disclosure> First, embodiments of this disclosure will be listed and described. The bolt assembly disclosed herein is (1) A bolt fitting having a screw shaft portion and a screw head provided on one end of the screw shaft portion, and an insulating finger-proof cap formed separately from the bolt fitting and detachably assembled to the screw head to cover the outer surface of the screw head, wherein the screw head has an engaging shaft portion that protrudes in the axial direction of the screw shaft portion in a direction away from the screw shaft portion, and the finger-proof cap has a recess into which the engaging shaft portion is fitted, and relative rotation between the finger-proof cap and the screw head is prevented by engaging portions provided on one of the outer circumferential surface of the engaging shaft portion and the inner circumferential surface of the recess engaging with a engaged portion provided on the other.

[0011] According to the bolt assembly of this disclosure, when fastening terminals together using the bolt assembly, the screw heads of the bolt fittings, which are highly likely to come into contact with the fingers of a worker, are covered by detachably installed insulating finger-prevention caps. This prevents or suppresses the worker from touching live parts during bolt fastening work. Moreover, the screw heads of the bolt assembly are often exposed to the outside and become live parts after fastening terminals together using the bolt assembly. Therefore, by covering the screw heads, which may become live parts after being exposed to the outside after bolt fastening work, with finger-prevention caps, the process of covering the work opening that exposes the head of the fastening bolt to the outside with a cap, which was required in conventional structures, can be eliminated. As described above, the bolt assembly of this disclosure can suppress the risk of electric shock to workers during and after bolt fastening, and finger-prevention measures can be implemented with a simple structure. In addition, the engagement of the engaging portion and the engaged portion, which are provided on one and the other outer circumferential surface of the engaging shaft and the inner circumferential surface of the recess respectively, prevents relative rotation between the finger-proof cap and the screw head. Therefore, the process of rotating the screw head via the finger-proof cap to screw the screw shaft portion (male thread) of the bolt assembly into the mating side (female thread) can be performed without any problems.

[0012] (2) In (1) above, it is preferable that the engaging portion is composed of a plurality of protrusions extending in the axial direction, provided at a plurality of locations on the outer circumferential surface of the engaging shaft portion that are spaced apart from each other in the circumferential direction, and the engaged portion is composed of a plurality of grooves extending in the axial direction, provided at a plurality of locations in the circumferential direction corresponding to the plurality of protrusions, opening to the inner circumferential surface and the opening side edge of the recess, and with the finger-prevention cap assembled to the screw head, the plurality of protrusions are fitted into the plurality of grooves, respectively. Since the engaging portion and the engaged portion are composed of a plurality of protrusions provided on the engaging shaft portion and a plurality of grooves provided in the recess, the process of rotating the screw head of the bolt assembly via the finger-prevention cap to screw the screw shaft portion (male thread) into the mating side (female thread) can be performed more advantageously.

[0013] (3) In (1) or (2) above, it is preferable that the screw head is provided on the screw shaft side of the engaging shaft and has a flange portion that extends radially outward from the screw shaft, and the finger-prevention cap has an annular flange cover that covers the surface of the flange portion on the engaging shaft side. Having a flange portion that extends radially outward from the screw shaft on the screw head allows the axial force of the bolt assembly to be stably applied to the fastening target such as terminals. Moreover, since the surface of the flange portion on the engaging shaft side, which has a high risk of contact with workers, etc., is covered by the flange cover of the finger-prevention cap, finger-prevention measures can be implemented with a simple structure without increasing the number of parts.

[0014] (4) In any one of (1) to (3) above, it is preferable that the finger-proof cap has an annular sealing member that is fitted onto the outer circumferential surface and sandwiched between the outer circumferential surface and the surrounding member surrounding the outer circumferential surface. The annular sealing member fitted onto the outer circumferential surface of the finger-proof cap covering the screw head of the bolt fitting is sandwiched between the outer circumferential surface and the surrounding member surrounding the outer circumferential surface, thereby ensuring waterproofness of the part fastened and fixed by the bolt assembly (such as between terminal parts).

[0015] (5) In any one of (1) to (4) above, it is preferable that an insulating tip-side finger-prevention cap is attached to the other end of the screw shaft portion. Since the tip side of the screw shaft portion is also covered with a tip-side finger-prevention cap, the risk of electric shock to workers, etc., by coming into contact with the bolt fitting can be further reduced.

[0016] (6) Preferably, in any one of (1) to (5) above, there is a retainer member that is fitted onto the finger-proof cap and engages with a surrounding member, and the finger-proof cap is prevented from detaching from the screw head by contact with the retainer member. With a simple structure in which only a retainer member that engages with a surrounding member is fitted onto the finger-proof cap, the finger-proof cap can be reliably prevented from detaching from the screw head, and the risk of electric shock to workers, etc. can be reliably suppressed even after bolt fastening.

[0017] <Details of Embodiments of the Present Disclosure> Specific examples of the bolt assembly of the present disclosure will be described below with reference to the drawings. It should be noted that the present disclosure is not limited to these examples, and is defined by the claims, and is intended to include all modifications within the scope and meaning equivalent to the claims.

[0018] <Embodiment 1> Hereinafter, the bolt assembly 10 according to Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 8. This bolt assembly 10 is provided, for example, in a vehicle such as an electric vehicle or a hybrid vehicle, and is used for bolting, for example, a first terminal 12 and a second terminal 14. Although not limited thereto, for example, the first terminal 12 is a member on the battery side, and the second terminal 14 is a member on the motor side as a load. When the first terminal 12 and the second terminal 14 are bolted by the bolt assembly 10, the battery and the motor are electrically connected. Although the first terminal 12 and the second terminal 14 fastened by the bolt assembly 10 can be arranged in any orientation in the vehicle, in the following description, the upper side refers to the upper side in FIG. 3, the lower side refers to the lower side in FIG. 3, the left side refers to the upper side in FIG. 2, the right side refers to the lower side in FIG. 2, the front side refers to the left side in FIG. 2, and the rear side refers to the right side in FIG. 2. In addition, in the following description, for a plurality of identical members, reference numerals are given only to some members, and reference numerals may be omitted for other members.

[0019] <Bolt Assembly 10> The bolt assembly 10 includes a screw shaft portion 16, a bolt fitting 20 having a screw head portion 18 provided on one end side (upper end side) of the screw shaft portion 16, and an insulating finger-touch prevention cap 24 formed separately from the bolt fitting 20, detachably assembled to the screw head portion 18 and covering an outer surface (for example, an upper surface 22) of the screw head portion 18.

[0020] <First Terminal 12> The specific shape of the first terminal 12 is not limited, but in Embodiment 1, as shown in Figure 6 and other figures, the first terminal 12 is generally a roughly rectangular flat plate with rounded corners, and a first bolt insertion hole 26 is formed at the tip (front end) of the first terminal 12, penetrating the first terminal 12 in the thickness direction (vertical direction). The busbar or wire on the battery side is electrically connected to the base (rear end) of the first terminal 12, so that the battery and the first terminal 12 are electrically connected. Such a first terminal 12 is formed from a metal with excellent conductivity, such as copper (including copper alloys) or aluminum (including aluminum alloys).

[0021] An intermediate terminal 28 is assembled into the first bolt insertion hole 26 of the first terminal 12. As shown in Figures 3 and 4, the intermediate terminal 28 has a roughly stepped cylindrical shape that extends vertically as a whole, and an intermediate through-hole 30 is formed in the central part of the intermediate terminal 28 that penetrates vertically and communicates with the first bolt insertion hole 26. The intermediate terminal 28 is made of a metal with excellent conductivity, for example, and the material of the intermediate terminal 28 is selected such that its natural potential is an intermediate value between that of the first terminal 12 and the second terminal 14. Specifically, for example, if the first terminal 12 is made of aluminum (including aluminum alloy) and the second terminal 14 is made of copper (including copper alloy), an aluminum-copper alloy (aluminum bronze) can be used as the material for the intermediate terminal 28. As a result, even when the potential difference between the metal material constituting the first terminal 12 and the metal material constituting the second terminal 14 is relatively large, corrosion due to a large potential difference between the first terminal 12 and the second terminal 14 can be prevented by providing an intermediate terminal 28 with an intermediate natural potential between them.

[0022] As described above, the relay terminal 28 has a roughly stepped cylindrical shape that extends vertically, with the upper part having a smaller outer diameter than the lower part. The smaller diameter cylindrical part at the top of the relay terminal 28 is the mounting cylinder part 32 that is assembled to the inner circumferential surface of the first bolt insertion hole 26 in the first terminal 12. The larger diameter cylindrical part at the bottom of the relay terminal 28 is a cylindrical projection 34 that protrudes downward, and when the first terminal 12 and the second terminal 14 are bolted together by the bolt assembly 10, the annular surface at the lower end of the cylindrical projection 34 and the annular surface at the upper end of the second terminal 14 come into contact with each other. In Embodiment 1, a plurality of press-fit ribs 36 are provided on the outer circumferential surface of the mounting cylinder portion 32 at predetermined distances from each other in the circumferential direction. When assembling the relay terminal 28 to the first terminal 12, the mounting cylinder portion 32 is press-fitted into the first bolt insertion hole 26 while each press-fit rib 36 slides against the inner circumferential surface of the first bolt insertion hole 26. In particular, in Embodiment 1, four recesses 38 that open downward are provided on the lower surface of the cylindrical projection 34 at predetermined distances from each other in the circumferential direction. When press-fitting the relay terminal 28 into the first terminal 12, damage to the contact portion (the contact surface with the second terminal 14) can be prevented by pressing each of these recesses 38 with a jig (not shown).

[0023] <2nd terminal 14> As shown in Figures 3 and 4, the second terminal 14 has a roughly cylindrical shape that extends vertically as a whole, and a second bolt insertion hole 40 is formed in the central part of the second terminal 14 that penetrates vertically and communicates with the intermediate through hole 30. Such a second terminal 14 is made of a metal such as copper (including copper alloys) or aluminum (including aluminum alloys) which has excellent conductivity. On the upper part of the inner circumferential surface of the second bolt insertion hole 40, a female thread 42 is formed that screws into a male thread 44, which will be described later, provided on the outer circumferential surface of the screw shaft portion 16 of the bolt fitting 20.

[0024] The first terminal 12 and the second terminal 14 described above are held by a first terminal retaining portion 43 (shown by a dashed line in Figures 3 and 4) and a second terminal retaining portion (not shown), respectively. The shapes of these first and second terminal retaining portions are not limited.

[0025] <Bolt fitting 20> As described above, the bolt fitting 20 comprises a screw shaft portion 16 and a screw head portion 18. A male thread 44 is formed on the outer circumferential surface of the screw shaft portion 16, which engages with the female thread 42 in the second bolt insertion hole 40. A lower insertion recess 45 is formed on the other end (lower end) of the screw shaft portion 16, opening downward and having a predetermined depth. On the other hand, the screw head portion 18 is provided with an engagement shaft portion 46 that protrudes upward in the direction away from the screw shaft portion 16 in the axial direction (vertical direction) of the screw shaft portion 16. The engagement shaft portion 46 is generally cylindrical in shape, and an upper insertion recess 48 is formed at the upper end of the engagement shaft portion 46, opening upward and having a predetermined depth.

[0026] In Embodiment 1, the outer circumferential surface 49 of the engaging shaft portion 46 is configured as a tapered surface whose outer diameter gradually increases downward. Furthermore, the screw head 18 has a flange portion 50 that is provided on the screw shaft portion 16 side of the engaging shaft portion 46 and extends radially outward from the screw shaft portion 16. The flange portion 50 is formed in an annular shape on the outer circumferential side from the screw head 18, and the screw head 18 as a whole is substantially disc-shaped. In other words, in Embodiment 1, the screw shaft portion 16 protrudes downward from the center of the screw head 18 (flange portion 50), and the engaging shaft portion 46 protrudes upward from the center of the screw head 18 (flange portion 50). The outer circumferential surface 49 of the engaging shaft portion 46 is provided with an engaging portion 52 that protrudes outward, and the flange portion 50 protrudes further outward than the engaging portion 52.

[0027] <Engagement portion 52> The engaging portion 52 is composed of multiple protrusions 54 that are provided at multiple locations on the outer circumferential surface 49 of the engaging shaft portion 46, spaced apart from each other in the circumferential direction, and extending in the axial direction (up and down direction). Each protrusion 54 is provided along the tapered outer circumferential surface 49 of the engaging shaft portion 46 with a substantially constant protrusion height in the longitudinal direction, and is formed to gradually incline towards the outer circumferential side as it goes downwards. In Embodiment 1, as shown in Figure 5 and other figures, each protrusion 54 is formed with a substantially triangular cross-section.

[0028] <Tip-proof finger-removal cap 56> In Embodiment 1, an insulating tip-side finger-prevention cap 56 is assembled to the other end (lower end) of the screw shaft portion 16 of the bolt fitting 20. The tip-side finger-prevention cap 56 is a substantially cylindrical member integrally equipped with an insertion portion 58 that is inserted into a lower insertion recess 45. In Embodiment 1, the tip-side finger-prevention cap 56 is attached to the lower end of the screw shaft portion 16 by press-fitting the insertion portion 58 into the lower insertion recess 45. The tip-side finger-prevention cap 56 may also be bonded or welded to the screw shaft portion 16 as needed.

[0029] Furthermore, the outer diameter of the tip-side finger-prevention cap 56 is slightly smaller than the outer diameter of the screw shaft portion 16, so that the tip-side finger-prevention cap 56 does not cover the outer circumferential surface of the lower end portion of the screw shaft portion 16. By providing the tip-side finger-prevention cap 56 at the lower end of the screw shaft portion 16 in this way, the lower end of the screw shaft portion 16 can be stably guided into the second bolt insertion hole 40 when fastening the bolt assembly 10, which will be described later, and the male screw 44 can be prevented from being damaged by contact with other members (for example, the relay terminal 28). In addition, by covering the lower end surface of the screw shaft portion 16 with the tip-side finger-prevention cap 56, it is possible to prevent electric shock by an unintentional contact of the lower end surface of the screw shaft portion 16 by a worker.

[0030] <Touch-proof cap 24> The finger-proof cap 24 is a cylindrical shape with a generally closed bottom that opens downwards, and is made of synthetic resin separately from the bolt fitting 20. The outer shape of the upper end of the finger-proof cap 24 is generally hexagonal in plan view, and this upper end constitutes an operating part 60 that allows fastening operations of the bolt assembly 10 (particularly the bolt fitting 20) using, for example, a tool not shown. Furthermore, in the middle of the vertical direction of the outer circumferential surface 61 of the finger-proof cap 24, a displacement restricting part 62 is formed, protruding outwards in an annular shape, which restricts the upward displacement of the annular sealing member 74 that is fitted onto the outer circumferential surface 61 of the finger-proof cap 24 as described later. In addition, below the displacement restricting part 62 on the finger-proof cap 24, an annular seal mounting part 64 is formed, the outer diameter of which is generally constant in the vertical direction, and into which the annular sealing member 74 is fitted.

[0031] As will be described later, when the finger-proof cap 24 is assembled to the screw head 18, the lower surface of the annular seal mounting portion 64 comes into contact with the radially intermediate portion of the surface (upper surface 22) of the flange portion 50 on the engagement shaft portion 46 side. Therefore, the annular flange cover of the finger-proof cap 24 that covers the surface (upper surface 22) of the flange portion 50 on the engagement shaft portion 46 side includes the annular seal mounting portion 64.

[0032] The finger-proof cap 24 is then superimposed on the engaging shaft portion 46 of the screw head 18 from above, so that the finger-proof cap 24 covers the outer surface of the screw head 18 (i.e., the outer circumferential surface 49 of the engaging shaft portion 46 and the upper surface 22 of the flange portion 50). In other words, the finger-proof cap 24 has a roughly bottomed cylindrical shape as described above, and a recess 66 is formed inside into which the engaging shaft portion 46 is fitted. This recess 66 has a shape that roughly corresponds to the engaging shaft portion 46, and the inner circumferential surface 68 of the recess 66 is configured as a tapered surface that roughly corresponds to the outer circumferential surface 49 of the engaging shaft portion 46 and gradually slopes outward towards the outer circumference as it goes downward. Furthermore, an engaged portion 70 is formed on the inner circumferential surface 68 of the recess 66 into which the engaging portion 52 provided on the outer circumferential surface 49 of the engaging shaft portion 46 engages. The engagement of the engagement portion 52 of the engagement shaft portion 46 and the engaged portion 70 of the recess 66 prevents relative rotation between the finger-proof cap 24 and the screw head 18. The engagement shaft portion 46 may be inserted into the recess 66 with a gap, or it may be inserted in a nearly press-fit state.

[0033] Furthermore, in Embodiment 1, an insertion portion 71 is formed on the bottom surface of the inner circumferential surface 68 of the recess 66 (the lower surface of the upper bottom wall portion of the finger-proof cap 24), protruding downward and being inserted into the upper insertion recess 48 of the engagement shaft portion 46 when the finger-proof cap 24 and the screw head 18 are assembled. This insertion portion 71 may be inserted with a gap between it and the upper insertion recess 48, or it may be inserted in a substantially press-fit state.

[0034] <Engaged portion 70> The engaged portion 70 is composed of multiple grooves 72 that extend axially and are provided at multiple locations in the circumferential direction corresponding to the multiple protrusions 54 that constitute the engaged portion 52, opening to the inner circumferential surface 68 of the recess 66 and the opening side edge (periphery of the lower opening). Each groove 72 is provided along the tapered inner circumferential surface 68 of the recess 66 with a substantially constant depth in the longitudinal direction, and is formed to gradually incline towards the outer circumference as it goes downwards. In Embodiment 1, as shown in Figure 5 and other figures, each groove 72 is formed with a substantially triangular cross-section, substantially corresponding to each protrusion 54. As a result, when the finger-proof cap 24 is assembled to the screw head 18, that is, when the engaged shaft portion 46 is housed in the recess 66, each of the multiple protrusions 54 is fitted into each of the multiple grooves 72. Each protrusion 54 may be inserted into each groove 72 with a gap between them, or it may be inserted in a substantially press-fit state.

[0035] <Annular sealing member 74> The bolt assembly 10 is fitted onto the outer circumferential surface 61 of the finger-proof cap 24 and includes an annular sealing member 74 that is sandwiched between the outer circumferential surface 61 and the peripheral member surrounding the outer circumferential surface 61. In Embodiment 1, as shown in Figures 3 and 4, a first terminal holding portion 43 for holding the first terminal 12 is arranged on the outer circumferential side of the finger-proof cap 24, and the peripheral member surrounding the outer circumferential surface 61 of the finger-proof cap 24 is formed by the first terminal holding portion 43. Therefore, when the first terminal 12 and the second terminal 14 are bolted together by the bolt assembly 10, the annular sealing member 74 is compressed in the radial direction of the bolt fitting 20 between the finger-proof cap 24 and the first terminal holding portion 43, so that the space between the bolt assembly 10 and the first terminal holding portion 43 is sealed in a liquid-tight manner.

[0036] Furthermore, when the finger-proof cap 24 is assembled to the screw head 18, as described above, the lower end of the annular seal mounting portion 64 abuts against the radially intermediate portion of the flange portion 50, and the displacement restricting portions 62 and flange portion 50 located on both the upper and lower sides of the annular seal mounting portion 64 protrude outward from the annular seal mounting portion 64. Since the annular seal member 74 is mounted on this annular seal mounting portion 64, these displacement restricting portions 62 and flange portion 50 are located on both the upper and lower sides of the annular seal member 74. Therefore, the displacement of the annular seal member 74 on both the upper and lower sides is restricted by the annular seal member 74 abutting against these displacement restricting portions 62 and flange portion 50.

[0037] <Retainer member 76> The bolt assembly 10 includes a retainer member 76 that is fitted onto the finger-proof cap 24 and engages with the first terminal holding portion 43, which is a peripheral member. The retainer member 76 is a substantially annular member as a whole and has a peripheral wall portion 78 that extends continuously around its entire circumference. Multiple engaging claws 80 are provided on the outer circumferential surface of the peripheral wall portion 78, and the retainer member 76 is fixed to the first terminal holding portion 43 by engaging claws 80 with engaging recesses 82 (see Figure 3) provided on the first terminal holding portion 43. When the retainer member 76 is fixed to the first terminal holding portion 43, the lower end of the peripheral wall portion 78 faces a displacement restricting portion 62 that protrudes outward from the outer circumferential surface 61 of the finger-proof cap 24 in the vertical direction. Therefore, even if the finger-proof cap 24 is displaced upward relative to the screw head 18, the displacement restricting portion 62 abuts against the lower end of the peripheral wall portion 78, thereby preventing the finger-proof cap 24 from detaching from the screw head 18.

[0038] Furthermore, when the first terminal 12 and the second terminal 14 are fastened together by the bolt assembly 10 and the retainer member 76 is fixed to the first terminal holding portion 43, the lower end of the peripheral wall portion 78 and the displacement restricting portion 62 may, for example, come into contact with each other at zero touch, thereby making vertical displacement of the finger-proof cap 24 virtually impossible. Alternatively, the lower end of the peripheral wall portion 78 and the displacement restricting portion 62 may have a predetermined vertical separation distance, and within this vertical separation distance, the finger-proof cap 24 may be able to move vertically.

[0039] The bolt assembly 10, with the structure described above, fastens the first terminal 12 and the second terminal 14 together with bolts. Specifically, as shown in Figure 6, the first terminal 12 and the second terminal 14 are positioned facing each other vertically, and then they are overlapped to connect the first bolt insertion hole 26 and the intermediate through hole 30 with the second bolt insertion hole 40 in the vertical direction. Subsequently, the screw shaft portion 16 of the bolt assembly 10 is inserted through the first bolt insertion hole 26 and the intermediate through hole 30, and the male thread 44 of the screw shaft portion 16 is screwed into the female thread 42 provided on the inner circumferential surface of the second bolt insertion hole 40. This bolt fastening causes the lower surface of the screw head 18 (flange portion 50) to overlap with the peripheral edge of the first bolt insertion hole 26 on the upper surface of the first terminal 12. Also, the peripheral edge of the first bolt insertion hole 26 on the lower surface of the first terminal 12 overlaps with the upper surface of the cylindrical projection 34 of the intermediate terminal 28. Furthermore, the lower surface of the cylindrical projection 34 is superimposed on the upper surface of the second terminal 14. In short, by fastening the bolt assembly 10, the first terminal 12 and the second terminal 14 are fixed in place, sandwiching the intermediate terminal 28, and the first terminal 12 and the second terminal 14, and consequently the battery and the motor, are electrically connected.

[0040] According to the bolt assembly 10 of Embodiment 1, which has the structure described above, a separate finger-proof cap 24 is attached to the screw head 18 of the bolt fitting 20. Therefore, when fastening the bolt assembly 10, the operating part 60 of the finger-proof cap 24 can be grasped with a tool (not shown) to perform the fastening work, reducing the risk of electric shock to the worker through the tool. The screw head 18 is provided with an engaging shaft portion 46, and the finger-proof cap 24 has a recess 66 into which the engaging shaft portion 46 is fitted. Furthermore, the engaging shaft portion 46 is provided with engaging portions 52 (each protrusion 54) that project outward to the outer circumference, and the recess 66 has engaged portions 70 (each groove 72) into which the engaging portions 52 engage. As a result, even when the anti-finger cap 24 is formed separately from the screw head 18, the anti-finger cap 24 and the screw head 18 can be rotated integrally around the central axis of the bolt fitting 20 during the fastening of the bolt assembly 10, thus avoiding problems such as only the anti-finger cap 24 rotating. In particular, since the anti-finger cap 24 is simply superimposed on the screw head 18 from above, assembly of the anti-finger cap 24 and the screw head 18 can be easily achieved.

[0041] The engaging portion 52 of the engaging shaft portion 46 is composed of multiple protrusions 54, and the engaged portion 70 of the recess 66 is composed of multiple grooves 72. When assembling the screw head 18 and the anti-finger contact cap 24, each protrusion 54 is fitted into each of the grooves 72. This ensures that engagement points between the engaging portion 52 and the engaged portion 70 are secured at multiple locations in the circumferential direction, allowing the anti-finger contact cap 24 and the screw head 18 to rotate more stably and integrally.

[0042] The screw head 18 has a flange portion 50, and the finger-proof cap 24 has a flange cover (annular seal mounting portion 64) that covers the surface (upper surface 22) of the flange portion 50 on the engagement shaft portion 46 side. When the bolt assembly 10 is fastened, the flange portion 50 of the screw head 18 is superimposed on the periphery of the first bolt insertion hole 26 on the upper surface of the first terminal 12, thereby allowing the axial force of the bolt assembly 10 (bolt fitting 20) to be applied to the first terminal 12. Furthermore, since the upper surface 22 of the flange portion 50 is also covered by the finger-proof cap 24, electric shock to workers caused by tools or the like coming into contact with the flange portion 50 can be prevented more reliably.

[0043] An annular sealing member 74 is fitted onto the finger-proof cap 24, and the annular sealing member 74 is sandwiched between the finger-proof cap 24 and the surrounding member (first terminal holding part 43 in Embodiment 1) when the bolt assembly 10 is fastened. As a result, the space between the finger-proof cap 24 (bolt assembly 10) and the surrounding member (first terminal holding part 43) is sealed liquid-tightly, preventing water from entering, for example, from the fastening point of the bolt assembly 10 into the second terminal holding part (not shown).

[0044] An insulating tip-side finger-prevention cap 56 is attached to the other end (lower end) of the screw shaft portion 16. For example, when assembling the bolt assembly 10 and the first terminal 12 by inserting the screw shaft portion 16 into the intermediate through-hole 30 of the intermediate terminal 28 before fastening the bolts of the bolt assembly 10, the screw shaft portion 16 in the bolt assembly 10 may also become a live part. In contrast, by attaching the tip-side finger-prevention cap 56 to the lower end of the screw shaft portion 16, it is possible to prevent workers from unintentionally coming into contact with the lower surface of the screw shaft portion 16 and receiving an electric shock. Furthermore, this tip-side finger-prevention cap 56 may be used as a guide when inserting into the second bolt insertion hole 40, or it may be designed to prevent the screw shaft portion 16 from coming into contact with other components (for example, the intermediate terminal 28, etc.) and being damaged.

[0045] A retainer member 76 that engages with a surrounding member (in Embodiment 1, the first terminal holding portion 43) is externally fitted to the anti-finger contact cap 24. The anti-finger contact cap 24, which is separate from the bolt fitting 20, comes into contact with the retainer member 76, thereby preventing the anti-finger contact cap 24 from falling off the bolt fitting 20. As a result, the anti-finger contact cap 24 can be prevented from falling off the bolt fitting 20 by assembling the retainer member 76 to the first terminal holding portion 43, without employing a special structure to fix the anti-finger contact cap 24 to the bolt fitting 20.

[0046] <Variation> While Embodiment 1 has been described in detail above as a specific example of the present disclosure, the present disclosure is not limited by this specific description. Modifications, improvements, etc., to the extent that they can achieve the objectives of the present disclosure are included in the present disclosure. For example, the following modifications of the embodiments are also included in the technical scope of the present disclosure.

[0047] (1) In the above embodiment, the retainer member 76 is fitted onto the anti-finger cap 24, and the anti-finger cap 24 is prevented from falling off by the retainer member 76 being assembled to the first terminal holding part 43, which is a peripheral member, but the invention is not limited to this embodiment. In this disclosure, the anti-finger cap is formed separately from the bolt fitting and is detachably assembled to the screw head to cover the outer surface of the screw head (for example, the upper surface 22), and for example, the anti-finger cap may be prevented from falling off the screw head by press-fitting the insertion part 71 in the above embodiment into the upper insertion recess 48 and / or press-fitting the engagement shaft part 46 into the recess 66.

[0048] (2) In the above embodiment, the engaging portion 52 was composed of a plurality of protrusions 54 and the engaged portion 70 was composed of a plurality of grooves 72, but the embodiment is not limited to this. For example, if the engaging portion is composed of protrusions and the engaged portion is composed of grooves, there should be at least one of each of these protrusions and grooves. The protrusions and grooves may be arranged in opposite directions, and the grooves as the engaged portion may be provided on the outer circumferential surface of the engaging shaft portion, and the protrusions as the engaging portion may be provided on the inner circumferential surface of the recess.

[0049] (3) The shapes of the first and second terminals are not limited in this disclosure. For example, the intermediate terminal fixed to the first terminal is not essential, and the first and second terminals may be directly superimposed on each other, and a bolt assembly inserted through the first bolt insertion hole of the first terminal may be screwed into a female thread provided on the inner surface of the second bolt insertion hole.

[0050] (4) In this disclosure, the tip-side finger-prevention cap 56 that is assembled to the threaded shaft portion 16 of the bolt fitting 20 is not essential. Even if a tip-side finger-prevention cap is provided, its shape is not limited, and the tip-side finger-prevention cap may be shaped to cover the outer circumferential surface of the lower end of the threaded shaft portion. Also, in this disclosure, the retainer member 76 is not essential, and even if a retainer member is provided, its shape is not limited. For example, the retainer member does not have to have an engaging claw portion, and may be assembled to a peripheral member (for example, the first terminal holding portion 43) by press-fitting or the like. [Explanation of Symbols]

[0051] 10 Bolt Assembly 12 1st terminal 14 2nd terminal 16 Screw shaft 18 Screw head 20 bolt fittings 22 Top surface (outer surface) 24 Finger-proof caps 26 First bolt insertion hole 28 Relay terminals 30 Relay through-holes 32 Mounting cylinder section 34 Cylindrical projection 36 Press-fit ribs 38 recessed area 40 Second bolt insertion hole 42 Female thread 43. First terminal holding part (peripheral member) 44 Male screw 45 Lower insertion recess 46 Engagement shaft part 48 Upper insertion recess 49 Outer surface (of the engaging shaft portion) 50 Flange section 52 Engaging part 54 protrusion 56 Finger-proof cap for the tip 58 Insertion part 60 Control section 61 Outer surface (of the anti-touch cap) 62 Displacement regulating section 64 Annular seal mounting section (flange cover) 66 recesses 68 Inner surface (of the recess) 70 Engaged portion 71 Insertion part 72 grooves 74 Annular sealing member 76 Retainer component 78 Peripheral wall 80 Engaging claw portion 82 Engagement recess

Claims

1. A bolt fitting having a screw shaft portion and a screw head portion provided on one end of the screw shaft portion, The bolt fitting is formed separately from the aforementioned bolt fitting and includes an insulating finger-proof cap that is detachably attached to the screw head and covers the outer surface of the screw head, The screw head has an engaging shaft portion that protrudes in the axial direction of the screw shaft portion, in a direction away from the screw shaft portion. The aforementioned finger-prevention cap has a recess into which the engaging shaft portion is fitted, A bolt assembly in which the relative rotation of the finger-preventing cap and the screw head is prevented by engaging a portion provided on one of the outer circumferential surface of the engaging shaft and the inner circumferential surface of the recess with a engaged portion provided on the other.

2. The engagement portion is composed of multiple protrusions extending in the axial direction, which are provided at multiple locations on the outer circumferential surface of the engagement shaft portion that are spaced apart from each other in the circumferential direction. The engaged portion is formed by a plurality of grooves that extend in the axial direction, opening to the inner circumferential surface and the opening side edge of the recess, and provided at a plurality of locations in the circumferential direction corresponding to the plurality of protrusions. The bolt assembly according to claim 1, wherein the finger-prevention cap is assembled to the screw head, and the plurality of protrusions are each fitted into the plurality of grooves.

3. The screw head is provided on the screw shaft side of the engaging shaft and has a flange portion that extends radially outward from the screw shaft. The bolt assembly according to claim 1 or claim 2, wherein the finger-prevention cap has an annular flange cover that covers the surface of the flange portion on the engagement shaft portion side.

4. The bolt assembly according to claim 1 or claim 2, further comprising an annular sealing member fitted onto the outer circumferential surface of the finger-prevention cap and sandwiched between the outer circumferential surface and a peripheral member surrounding the outer circumferential surface.

5. The bolt assembly according to claim 1 or claim 2, further comprising an insulating tip-side finger-prevention cap attached to the other end of the screw shaft portion.

6. The aforementioned finger-proof cap has a retainer member that is fitted onto the surrounding member and engages with the surrounding member, The bolt assembly according to claim 1 or claim 2, wherein the finger-touch prevention cap is prevented from detaching from the screw head by contact with the retainer member.

Images