Fusible Link Unit

Abstract

To provide a fusible link unit capable of suppressing erroneous assembly to a battery terminal with a simple configuration.SOLUTION: A fusible link unit 1 includes a bus bar 2 including a connection portion 21 having a through hole 21a through which a bolt 46 of a battery terminal 40 is inserted, a housing 3 for holding the bus bar with the connection portion being exposed, and a fusible link which is held by a housing and connected to the bus bar. The housing has a rib 33 that restricts erroneous assembly to the battery terminal. When it is attempted to insert a bolt through the through hole in a state where the housing is set to face a wrong direction, the rib interferes with the battery terminal or a battery post, and in a state where the housing is oriented in a correct direction, the rib does not interfere with either the battery terminal or the battery post, thereby allowing the bolt to pass through the through hole.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a fusible link unit. [Background technology]

[0002] Conventionally, there are techniques for connecting conductors to battery terminals. Patent Document 1 discloses a battery terminal connection structure for connecting a battery terminal to a battery terminal. In the battery terminal of Patent Document 1, the outer diameters of each post are different for the positive and negative poles, and the distance between the abutment surfaces provided at opposing positions on the outer periphery of each base is set to have a size relationship between the positive and negative poles that is the opposite of the size relationship between the outer diameters of the posts. The battery terminal has a flat plate portion through which post insertion holes corresponding to the outer diameters of the posts are formed, and a pair of opposing wall portions erected at a distance corresponding to the distance between the abutment surfaces of the bases.

[0003] The battery terminal connection structure of Patent Document 1 is described as preventing incorrect connection of a battery terminal to a battery terminal, regulating the connection direction of the terminal, and facilitating the connection work. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-256962 Summary of the Invention [Problem to be solved by the invention]

[0005] There is still room for improvement in preventing incorrect assembly to the battery terminal. For example, it would be preferable to simplify the structure for preventing incorrect assembly.

[0006] An object of the present invention is to provide a fusible link unit that has a simple configuration and can prevent incorrect assembly to a battery terminal. [Means for solving the problem]

[0007] The fusible link unit of the present invention comprises a bus bar having a connection portion with a through hole formed therein through which a bolt of a battery terminal is inserted, a housing that holds the bus bar with the connection portion exposed, and a fusible link that is held by the housing and connected to the bus bar, wherein the housing has a rib that prevents incorrect assembly to the battery terminal, and the rib interferes with the battery terminal or battery post when an attempt is made to insert the bolt into the through hole with the housing facing in the incorrect direction, and does not interfere with either the battery terminal or the battery post when the housing is facing in the correct direction, allowing the bolt to be inserted into the through hole. [Effects of the Invention]

[0008] In the fusible link unit according to the present invention, the rib of the housing interferes with the battery terminal or the battery post when an attempt is made to insert a bolt into the through hole with the housing facing in the wrong direction. The fusible link unit according to the present invention has an advantageous effect of being able to suppress incorrect assembly with the battery terminal with a simple configuration. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view of a fusible link unit according to an embodiment. [Figure 2] FIG. 2 is a side view of the fusible link unit according to the embodiment. [Figure 3] FIG. 3 is a perspective view of a battery terminal according to the embodiment. [Figure 4] FIG. 4 is a perspective view of the fusible link unit according to the embodiment. [Figure 5] FIG. 5 is a perspective view of the fusible link unit according to the embodiment. [Figure 6]FIG. 6 is a side view showing the fusible link unit in the correct orientation. [Figure 7] FIG. 7 is a cross-sectional view showing the fusible link unit in the correct orientation. [Figure 8] FIG. 8 is a cross-sectional view showing a provisionally locked fusible link unit. [Figure 9] FIG. 9 is a cross-sectional view of a fusible link unit fastened to a battery terminal. [Figure 10] FIG. 10 shows a fusible link unit in the wrong orientation. [Figure 11] FIG. 11 is a cross-sectional view showing a rib that interferes with a battery terminal. [Figure 12] FIG. 12 is a side view of a fusible link unit according to a first modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A fusible link unit according to an embodiment of the present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to the embodiment. Furthermore, the components in the following embodiments include those that can be easily imagined by a person skilled in the art or those that are substantially the same.

[0011] [Embodiment] An embodiment will be described with reference to Fig. 1 to Fig. 11. This embodiment relates to a fusible link unit. Fig. 1 is a plan view of the fusible link unit according to the embodiment, Fig. 2 is a side view of the fusible link unit according to the embodiment, Fig. 3 is a perspective view of a battery terminal according to the embodiment, Figs. 4 and 5 are perspective views of the fusible link unit according to the embodiment, Fig. 6 is a side view showing the fusible link unit in the correct orientation, Fig. 7 is a cross-sectional view showing the fusible link unit in the correct orientation, Fig. 8 is a cross-sectional view showing a fusible link unit that has been provisionally locked, and Fig. 9 is a cross-sectional view of the fusible link unit fastened to a battery terminal.

[0012] Fig. 10 shows a fusible link unit in the wrong orientation, and Fig. 11 is a cross-sectional view showing a rib interfering with a battery terminal. Fig. 7 shows a cross-section taken along line VII-VII of Fig. 6. Fig. 8 shows a cross-section taken along line VIII-VIII of Fig. 2.

[0013] As shown in FIGS. 1 and 2, the fusible link unit 1 of this embodiment is assembled to a battery terminal 40. The battery terminal 40 is fixed to a battery post 120 of a battery 100. The illustrated battery post 120 is disposed in a recess 110a of a housing 110 of the battery 100. The recess 110a is provided, for example, in a corner of the lid of the housing 110. The battery post 120 protrudes from a first surface 111 of the recess 110a. The fusible link unit 1 is assembled to the battery 100 with the first surface 111 facing upward, for example.

[0014] As shown in FIGS. 1 to 3 , the battery terminal 40 includes a main body 41, a bolt 42, a nut 43, a terminal portion 44, a holding portion 45, and a bolt 46. The main body 41, the terminal portion 44, and the holding portion 45 are integrally formed from a conductive metal plate. The main body 41 has a substantially C-shape in plan view and includes a slit 41a. The battery post 120 is inserted into the main body 41. The main body 41 is fastened to the battery post 120 by the bolt 42 and the nut 43.

[0015] The terminal portion 44 and the holding portion 45 protrude from the main body 41 along a first direction X. The first direction X is the longitudinal direction of the battery terminal 40. A direction perpendicular to the first direction X when the battery terminal 40 is viewed in a plan view is referred to as a "second direction Y." The second direction Y is the width direction of the battery terminal 40. A direction perpendicular to both the first direction X and the second direction Y is referred to as a "third direction Z." The battery post 120 is inserted into the main body 41 along the third direction Z.

[0016] The terminal portion 44 is a portion that is electrically connected to the bus bar 2 of the fusible link unit 1. The terminal portion 44 is bent to form a generally rectangular cylindrical shape. The terminal portion 44 has a through hole 44a through which the bolt 46 is inserted. The retaining portion 45 is a portion that retains the bolt 46. As shown in FIG. 7 , the retaining portion 45 accommodates the head 46c of the bolt 46 and retains the head 46c so that it cannot rotate. The male thread portion 46a of the bolt 46 protrudes from the through hole 44a along the third direction Z.

[0017] 2 and other figures, the battery terminal 40 is fixed to the battery post 120 with the terminal portion 44 protruding from the housing 110 in the first direction X. The bolt 46 is spaced apart from the housing 110 in the first direction X.

[0018] 4 and 5, the fusible link unit 1 includes a bus bar 2, a housing 3, a fusible link 4, a terminal 5, and a bolt 6. The bus bar 2 is formed of a conductive metal plate. The bus bar 2 includes a flat connecting portion 21. The connecting portion 21 includes a through hole 21a through which the male thread portion 46a of the bolt 46 is inserted. The axial direction of the through hole 21a is the height direction Z1.

[0019] Terminal 5 is an output terminal and is connected to a terminal on the load side. Terminal 5 is flat and made of a conductive metal plate. Terminal 5 has a through hole 51 through which a bolt 6 is inserted. Fusible link 4 is interposed between bus bar 2 and terminal 5. Fusible link 4 cuts off the connection between bus bar 2 and terminal 5 when an overcurrent flows between bus bar 2 and terminal 5.

[0020] The housing 3 holds the bus bar 2, the fusible link 4, the terminal 5, and the bolt 6. The housing 3 is molded, for example, from an insulating synthetic resin. The housing 3 may be molded integrally with the bus bar 2, the fusible link 4, the terminal 5, and the bolt 6. The illustrated housing 3 is integrated with the bus bar 2 by insert molding and holds the bus bar 2.

[0021] The housing 3 has a flat plate-shaped first holding portion 31 and a flat plate-shaped second holding portion 32. The first holding portion 31 is a portion that holds the bus bar 2. The second holding portion 32 is a portion that holds the fusible link 4, the terminal 5, and the bolt 6. The first holding portion 31 and the second holding portion 32 are perpendicular to each other. That is, the shape of the housing 3 in a side view is substantially L-shaped.

[0022] The first holding portion 31 has a notch 31a that exposes the connection portion 21 of the busbar 2. The shape of the notch 31a in a plan view is an arc. The notch 31a is formed concentrically with the through hole 21a of the connection portion 21. In other words, the through hole 21a is located at the center of the area surrounded by the notch 31a.

[0023] In the description of the fusible link unit 1, the direction in which the first retaining portion 31 extends will be referred to as the "extension direction X1." Furthermore, the direction perpendicular to the extension direction X1 when the first retaining portion 31 is viewed in a plan view will be referred to as the width direction Y1. Furthermore, the direction in which the second retaining portion 32 extends will be referred to as the "height direction Z1." When the fusible link unit 1 is assembled to the battery terminal 40 in the correct posture, the extension direction X1 coincides with the first direction X, the width direction Y1 coincides with the second direction Y, and the height direction Z1 coincides with the third direction Z.

[0024] A rib 33 is provided at the tip of the first holding portion 31. The rib 33 protrudes from the first holding portion 31 in the height direction Z1. The protruding direction of the rib 33 is the same as the protruding direction of the second holding portion 32 relative to the first holding portion 31. In other words, the rib 33 faces the second holding portion 32 in the extension direction X1.

[0025] 4, the housing 3 has a pair of ribs 33a, 33b. The ribs 33a, 33b are arranged on both sides of the connecting portion 21 in the width direction Y1. In other words, the pair of ribs 33a, 33b are arranged on both sides of the connecting portion 21. The pair of ribs 33a, 33b face each other in the width direction Y1. One rib 33a is arranged at one end of the first holding portion 31 in the width direction Y1, and the other rib 33b is arranged at the other end of the first holding portion 31 in the width direction Y1. The size of the gap provided between the pair of ribs 33a, 33b corresponds to the width of the terminal portion 44.

[0026] The ribs 33 are provided at their tip ends with claws 34 that protrude in the width direction Y1. The claws 34 are temporary locking portions that are temporarily locked by the battery terminals 40. The claws 34 of the rib 33a protrude toward the rib 33b. The claws 34 of the rib 33b protrude toward the rib 33a.

[0027] 6 and 7 show the fusible link unit 1 assembled to the battery terminal 40 in the correct orientation. The correct orientation is an orientation in which the second holding portion 32 faces the battery terminal 40 in the first direction X. In this case, the first holding portion 31 extends along the first direction X. In the correct orientation, the tip surface of the first holding portion 31 faces the battery post 120 in the first direction X. The worker moves the fusible link unit 1 along the third direction Z and inserts the bolt 46 of the battery terminal 40 into the through hole 21a of the busbar 2.

[0028] As shown in FIG. 7 , the bolt 46 has a small-diameter portion 46b. The small-diameter portion 46b protrudes from the tip of the male thread portion 46a and has a smaller diameter than the male thread portion 46a. The small-diameter portion 46b facilitates insertion of the male thread portion 46a into the through-hole 21a of the busbar 2. As shown in FIG. 7 , when the male thread portion 46a is inserted into the through-hole 21a, the pair of ribs 33a, 33b face the terminal portion 44. More specifically, the tip portions of the ribs 33a, 33b face the side surface 44b of the terminal portion 44 in the second direction Y. In other words, the male thread portion 46a guides the rib 33 to the side of the terminal portion 44 so as not to collide with the rib 33. In other words, the terminal portion 44 is guided between the pair of ribs 33a, 33b without interfering with the rib 33.

[0029] 6, when the male thread portion 46a is inserted into the through-hole 21a, the rib 33 is spaced apart from the battery post 120. In other words, when the housing 3 is oriented correctly, the rib 33 does not interfere with the battery post 120, allowing the bolt 46 to be inserted into the through-hole 21a.

[0030] When the fusible link unit 1 is further moved in the third direction Z from the state shown in Fig. 7, the terminal portion 44 passes between the two claws 34. The side surface 44b of the terminal portion 44 comes into contact with the claws 34 and passes between the two claws 34 while elastically deforming the pair of ribs 33a, 33b. As a result, as shown in Fig. 8, the pair of ribs 33a, 33b engage with the battery terminal 40. The claw 34 is locked by the locking surface 47 of the battery terminal 40. The locking surface 47 is, for example, the bottom surface of the terminal portion 44 and the bottom surface of the holding portion 45.

[0031] The fusible link unit 1 is provisionally locked by engaging the pair of ribs 33a, 33b with the battery terminal 40. In the provisionally locked state, the bolt 46 is inserted into the through hole 21a of the bus bar 2. That is, the claws 34 of the pair of ribs 33a, 33b are locked by the battery terminal 40 with the bolt 46 inserted into the through hole 21a. In the provisionally locked state, the male thread portion 46a is inserted into the through hole 21a up to the base end.

[0032] In the provisionally locked state, the claws 34 restrict the inclination of the fusible link unit 1 with respect to the third direction Z. The claws 34 maintain, for example, a state in which the connecting portion 21 is perpendicular to the third direction Z, or a state in which the connecting portion 21 is substantially perpendicular to the third direction Z.

[0033] 9, the nut 7 is threaded onto the bolt 46, thereby fastening the connection portion 21 and the terminal portion 44 together. The fusible link unit 1 of this embodiment reduces the occurrence of problems when the nut 7 is threaded onto the bolt 46. For example, deformation of the busbar 2, which occurs when the connection portion 21 is inclined, is prevented. Furthermore, the fusible link unit 1 is provisionally locked to the battery terminal 40, improving the workability of the assembly work.

[0034] As will be described below, the fusible link unit 1 of this embodiment can prevent incorrect assembly. Fig. 10 shows a fusible link unit 1 that is about to be assembled in an incorrect orientation. The orientation of the housing 3 shown in Fig. 10 is such that the second holding portion 32 faces the battery terminal 40 in the second direction Y. In this case, the width direction Y1 of the fusible link unit 1 coincides with the first direction X of the battery terminal 40.

[0035] If an attempt is made to insert the bolt 46 into the through-hole 21a of the busbar 2 when the housing 3 is oriented incorrectly, the rib 33 will interfere with the battery terminal 40. In FIG. 10 , one of the ribs 33a abuts against the body 41 of the battery terminal 40. More specifically, as shown in FIG. 11 , the tip 35 of the rib 33a abuts against the body 41. The worker will notice that the orientation of the fusible link unit 1 is incorrect when the rib 33a interferes with the battery terminal 40. Therefore, the fusible link unit 1 of this embodiment can prevent incorrect assembly from occurring.

[0036] 11, the tip of the small diameter portion 46b of the bolt 46 has already entered the through-hole 21a when the rib 33a interferes with the battery terminal 40. In other words, the rib 33a interferes with the battery terminal 40 before the male thread portion 46a of the bolt 46 is inserted into the through-hole 21a. This makes it possible to let the worker know at an early stage that the orientation of the fusible link unit 1 is incorrect.

[0037] Furthermore, because the rib 33a abuts against the battery terminal 40, the male thread portion 46a cannot be inserted into the through hole 21a. As shown in FIG. 11 , while one rib 33a abuts against the battery terminal 40, the other rib 33b is not abutting against the battery terminal 40. Therefore, the rib 33b can move further in the direction indicated by the arrow Ar1. As a result, the connection portion 21 is tilted, and the through hole 21a becomes eccentric with respect to the central axis of the bolt 46. This causes the male thread portion 46a to abut against the connection portion 21, making it impossible for the male thread portion 46a to be inserted into the through hole 21a. In other words, even if an operator tries to forcibly assemble a fusible link unit 1 in an incorrect position to the battery terminal 40, the assembly will not be successful.

[0038] 11, the rib 33a abuts against the inclined portion 41b of the main body 41. The inclined portion 41b is inclined so as to guide the rib 33a toward the bolt 46. The inclined portion 41b makes the through hole 21a eccentric with respect to the bolt 46, making it impossible to insert the male thread portion 46a into the through hole 21a.

[0039] The rib 33 may be configured to interfere with the battery post 120 when the orientation of the housing 3 is incorrect. For example, the rib 33a may be arranged to interfere with the battery post 120 when the housing 3 is oriented as shown in Fig. 10. In this case, the rib 33 is configured to allow the bolt 46 to be inserted into the through-hole 21a without interfering with either the battery terminal 40 or the battery post 120 when the orientation of the housing 3 is correct.

[0040] As described above, the fusible link unit 1 according to this embodiment includes the bus bar 2, the housing 3, and the fusible link 4. The bus bar 2 has a connection portion 21 formed with a through hole 21a through which the bolt 46 of the battery terminal 40 is inserted. The housing 3 holds the bus bar 2 with the connection portion 21 exposed. The fusible link 4 is held by the housing 3 and connected to the bus bar 2.

[0041] The housing 3 has a rib 33 that prevents incorrect assembly relative to the battery terminal 40. If an attempt is made to insert the bolt 46 into the through-hole 21a with the housing 3 facing in the wrong direction, the rib 33 will interfere with the battery terminal 40 or the battery post 120. On the other hand, when the housing 3 is facing in the correct direction, the rib 33 does not interfere with either the battery terminal 40 or the battery post 120, allowing the bolt 46 to be inserted into the through-hole 21a. Therefore, the fusible link unit 1 of this embodiment can prevent incorrect assembly with a simple configuration.

[0042] The housing 3 of this embodiment has a pair of ribs 33a, 33b. The pair of ribs 33a, 33b are arranged on both sides of the connection portion 21. The housing 3 having the pair of ribs 33a, 33b can more reliably prevent incorrect assembly. The pair of ribs 33a, 33b can also function as a guide that guides the connection portion 21 to the correct position. For example, the pair of ribs 33a, 33b of this embodiment has an alignment function that aligns the through hole 21a with the bolt 46.

[0043] The housing 3 of this embodiment has a pair of ribs 33a, 33b that protrude along the axial direction of the through-hole 21a. The pair of ribs 33a, 33b has a claw 34 that is engaged with the battery terminal 40 when the bolt 46 is inserted into the through-hole 21a. The claw 34, which serves as a temporary engagement portion, improves the workability of assembling the fusible link unit 1 to the battery terminal 40.

[0044] The number of ribs 33 provided on the housing 3 may be one. For example, if the orientation of the housing 3 in which incorrect assembly may occur is only the orientation shown in Fig. 10, only the rib 33a may be provided on the housing 3, and the rib 33b may not be provided.

[0045] The shape of the housing 3 is not limited to the illustrated L-shape, but may be, for example, a straight shape that holds the busbars 2 and the terminals 5 aligned in a straight line.

[0046] The rib 33 may not have the claw 34. In this case, the housing 3 may have a temporary locking portion other than the claw 34 of the rib 33. The temporary locking portion other than the rib 33 may be configured to engage with the battery terminal 40 when the housing 3 is oriented correctly, and not to engage with the housing 3 when the housing 3 is oriented incorrectly.

[0047] [First Modification of the Embodiment] A first modified example of the embodiment will be described. Fig. 12 is a side view of a fusible link unit according to the first modified example of the embodiment. The first modified example of the embodiment differs from the above embodiment in that it has a rib 36 instead of the rib 33 of the embodiment.

[0048] As shown in FIG. 12 , the housing 3 has a rib 36. The rib 36 protrudes from the second retaining portion 32 in the extension direction X1. The protruding direction of the rib 36 is the same as the protruding direction of the first retaining portion 31 relative to the second retaining portion 32. The rib 36 is disposed, for example, at an end of the second retaining portion 32 in the width direction Y1. The housing 3 may have two ribs 36. In this case, the two ribs 36 are preferably disposed on both sides of the connecting portion 21 in the width direction Y1.

[0049] The rib 36 is configured so that it interferes with the battery terminal 40 or the battery post 120 when an attempt is made to insert the bolt 46 into the through-hole 21a with the housing 3 facing in the wrong direction. The rib 36 is also configured so that it does not interfere with either the battery terminal 40 or the battery post 120 when the housing 3 is facing in the correct direction, allowing the bolt 46 to be inserted into the through-hole 21a.

[0050] [Second Modification of the Embodiment] A second modification of the embodiment will be described. The battery terminal 40 may have a stopper that restricts the relative rotation of the battery terminal 40 with respect to the housing 110. The stopper has, for example, an engaging portion that engages with the main body 41 and the terminal portion 44, and is attached to the main body 41 and the terminal portion 44. The stopper may be a resin member. The rib 33 of the above embodiment may be configured to engage with the stopper. In this case, the claw 34 of the rib 33 is locked by the stopper.

[0051] The rib 33 of the above embodiment and the rib 36 of the first modified example may be configured to interfere with the stopper when the orientation of the housing 3 is incorrect. The stopper may be provided with an abutment portion that interferes with the rib 33 or the rib 36 when the orientation of the housing 3 is incorrect.

[0052] The contents disclosed in the above-described embodiments and modifications can be implemented in appropriate combinations. [Explanation of symbols]

[0053] 1 Fusible link unit 2: bus bar; 21: connection portion; 21a: through hole 3: Housing, 31: First holding portion, 31a: Notch, 32: Second holding portion 33, 33a, 33b: Rib, 34: Claw (temporary locking portion), 35: Tip, 36: Rib 4 fusible links 5:Terminal, 51:Through hole 6: Bolt, 7: Nut 40: Battery terminal, 41: Main body, 41a: Slit, 41b: Inclined portion 42: Bolt, 43: Nut 44: Terminal portion, 45: Holding portion, 46: Bolt, 46a: Male thread portion 47: Locking surface 100: Battery, 110: Housing, 111: First surface, 120: Battery post X: first direction, Y: second direction, Z: third direction X1: Extension direction, Y1: Width direction, Z1: Height direction

Claims

1. a bus bar having a connection portion formed with a through hole through which a bolt of a battery terminal is inserted; a housing that holds the bus bar with the connection portion exposed; a fusible link held by the housing and connected to the bus bar; Equipped with The housing has a rib that prevents incorrect assembly with respect to the battery terminal. the rib interferes with the battery terminal or the battery post when the bolt is to be inserted into the through hole with the housing facing in an incorrect direction, and does not interfere with either the battery terminal or the battery post when the housing is facing in the correct direction, allowing the bolt to be inserted into the through hole; The housing has a pair of ribs that protrude in the axial direction of the through hole, The pair of ribs have provisional locking portions that are locked by the battery terminals when the bolts are inserted through the through holes. A fusible link unit characterized by:

2. The pair of ribs are arranged on both sides of the connection portion.

2. The fusible link unit according to claim 1.

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