Shunt fixture for reducing contact resistance and method of installation

Abstract

The application provides a shunt fixing device and mounting method for reducing contact resistance, which comprises a shell, a conductive hard row and a shunt, the shunt is respectively provided with a first connecting hole and a second connecting hole at both ends, the preset holes of the conductive hard row include a first preset hole corresponding to the first connecting hole and a second preset hole corresponding to the second connecting hole, the shell is provided with a avoiding space for avoiding the connection between the shunt and the conductive hard row, and the conductive hard row is fixed on the fixed column in the shell. The shunt is finally freely fixed on the conductive hard row by bolts passing through the first connecting hole, the first preset hole, the second connecting hole and the second preset hole, compared with fixing the hard row and the shunt on the shell, the influence of deformation stress on the contact performance is avoided, the contact performance of the two is greatly improved, and the beneficial effect of reducing the contact resistance is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy vehicle shunt, in particular to a shunt fixing device for reducing contact resistance and a fixing installation method. BACKGROUND

[0002] The shunt is made according to the principle that the DC current flowing through the resistor produces a voltage drop, which is equivalent to a resistor with very small resistance. When DC current passes through, a voltage drop is generated, and the shunt is externally connected to a voltmeter to determine the current value flowing through the shunt according to the voltage drop.

[0003] The contact resistance of the shunt for new energy vehicles after being fixed at both ends is extremely strict, and the following several schemes are currently used:

[0004] First, a soft cable is used at both ends of the shunt, but the cost of soft cable is relatively high compared to hard cable, so this scheme is less used.

[0005] Second, a conductive hard cable is used, such as the existing shunt fixing device exploded view shown in FIG. 1. Figure 1 The fixing installation process is as follows: first, the fixing nut 100 is fixed on the fixed seat in the shell 10 by injection molding process, then the first copper bar 21, the second copper bar 22 and the shunt 3 are placed in order, the first copper bar 21, the second copper bar 22 and the shunt 3 are respectively provided with a first through hole 210, a second through hole 220, a first connecting hole 31 and a second connecting hole 32, and finally two bolts 4 are respectively threaded through the first connecting hole 31, the first through hole 210, the second connecting hole 32 and the second through hole 220 and screwed to the fixing nut 100 in the shell, so that the copper bar and the shunt are finally fixed on the shell. Due to the "seesaw" effect, the "clamping force" of the fixing nut 100 for fixing the shunt is used to "clamp" the copper bar and the shunt, and on the other hand, it is used to overcome the deformation stress of the "seesaw" effect, which greatly affects the contact performance of the copper bar and the shunt, and inevitably makes the contact resistance larger, which makes the contact resistance exceed the tolerance, causes the local temperature to be too high, and once the shunt's bearing temperature capacity is exceeded, the BMS is forced to reduce the output power, which further affects the driving experience of the vehicle.

[0006] Therefore, for the researchers in the field, it is urgent to develop a shunt fixing device and fixing installation method for reducing contact resistance. SUMMARY

[0007] In view of this, in order to solve the above problems, the embodiment of the present application provides a shunt fixing device for reducing contact resistance and a mounting method, the shunt is fixed on the conductive hard row through the first connecting hole, the first preset hole, the second connecting hole and the second preset hole, so that the shunt is freely fixed on the conductive hard row, and compared with fixing the hard row and the shunt on the shell, the influence of deformation stress on the contact performance is avoided, the contact performance of the copper row and the shunt is greatly improved, and the technical problem of affecting the whole vehicle driving experience due to the excessive contact resistance is prevented.

[0008] In order to achieve the above-mentioned purpose, the embodiment of the present application provides a shunt fixing device for reducing contact resistance, which comprises a shunt, the two ends of the shunt are respectively provided with a first connecting hole and a second connecting hole; a conductive hard row, comprising a preset hole fixedly connected with the shunt, the preset hole comprises a first preset hole corresponding to the first connecting hole and a second preset hole corresponding to the second connecting hole, the shunt is fixed on the conductive hard row through the first connecting hole, the first preset hole, the second connecting hole and the second preset hole; a shell, the shell is provided with an avoiding space for avoiding the connection between the shunt and the conductive hard row, and the conductive hard row is fixed on the fixing column in the shell.

[0009] Further, the conductive hard row comprises a first copper row and a second copper row respectively electrically connected with the two ends of the shunt, the first preset hole is arranged on the first copper row, and the second preset hole is arranged on the second copper row.

[0010] Further, the first preset hole and the second preset hole are provided with a press-in rivet nut on the side away from the shunt.

[0011] Further, the space provided in the shell for avoiding the connection between the shunt and the conductive hard row is a cylindrical hole, and the hole diameter of the cylindrical hole is greater than the maximum outer diameter of the press-in rivet nut.

[0012] Further, the first copper row and the second copper row are respectively provided with a third through hole and a fourth through hole for fixing them on the shell at one end close to the shunt, and the third through hole and the fourth through hole are diagonally arranged along the shunt.

[0013] Further, the shell is provided with a first fixing part and a second fixing part corresponding to the third through hole and the fourth through hole, the first fixing part and the second fixing part are rivet nuts pressed into the shell, and two bolts are respectively screwed into the rivet nuts of the first fixing part and the second fixing part through the third through hole and the fourth through hole, so as to fix the conductive hard row.

[0014] Further, the first connecting hole, the second connecting hole, the first preset hole and the second preset hole are at least two.

[0015] Further, the plating layer of the conductive hard row adopts tin plating.

[0016] Another aspect of the embodiment of the present application provides a shunt fixing installation method for reducing contact resistance, the method comprising the following steps:

[0017] S30, the shunt is fixed on the conductive hard row by respectively passing the first connecting hole, the first preset hole, and the second connecting hole, the second preset hole through the bolt;

[0018] S40, the conductive hard row is fixed on the fixed column of the shell.

[0019] Further, before step S30, it further comprises:

[0020] S10, the press-in rivet nut is pressed into the first preset hole and the second preset hole of the conductive hard row away from the side of the shunt;

[0021] S20, the conductive hard row with the press-in rivet nut is placed on the shell, and the press-in rivet nut is placed in the space provided in the shell for avoiding the connection between the shunt and the conductive hard row.

[0022] Further, the step S30 of fixing the shunt on the conductive hard row specifically comprises:

[0023] S301, the bolt is screwed on the press-in rivet nut in the first preset hole through the first connecting hole, and is screwed on the press-in rivet nut in the second preset hole through the second connecting hole.

[0024] Further, the step S40 of fixing the conductive hard row on the shell specifically comprises:

[0025] S401, the conductive hard row comprises a first copper row and a second copper row electrically connected to both ends of the shunt respectively, and is fixed on the shell through the fixing holes provided on the first copper row and the second copper row and diagonally arranged along the shunt.

[0026] The beneficial effects of the present application are:

[0027] The present application fixes the shunt on the conductive hard row by respectively passing the first connecting hole, the first preset hole, and the second connecting hole, the second preset hole through the bolt, so that the shunt is freely fixed on the conductive hard row, which avoids the influence of deformation stress on the contact performance, greatly improves the contact performance of the conductive hard row and the shunt, ensures that the contact resistance of the two is within a certain threshold range, and prevents the technical problem that the whole vehicle driving experience is affected due to the out-of-tolerance contact resistance.

[0028] Furthermore, by setting the first connecting hole and the second connecting hole at two ends of the shunt, and the first preset hole of the first copper bar and the second preset hole of the second copper bar as at least two, when the shunt is fixed to the conductive hard bar, diagonal uniform fixing bolts can be used, so that the contact force between the shunt and the conductive hard bar is more uniform, which is beneficial to improve the contact performance of the conductive hard bar and the shunt, and prevent the contact resistance from being too large to affect the driving experience of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0029] The following drawings are used to provide further understanding of the present application, constitute a part of the present application, and are only intended to illustrate and explain the present application, and are not intended to limit the scope of the present application. In the drawings:

[0030] Figure 1 It is an exploded structural schematic diagram of the existing shunt fixing device;

[0031] Figure 2 It is an exploded structural schematic diagram of the shunt fixing device in the embodiment of the present application;

[0032] Figure 3 It is a structural schematic diagram of the conductive hard bar after being pressed into the pressure rivet nut 20 in another embodiment of the present application;

[0033] Figure 4 It is a structural schematic diagram of the shell in another embodiment of the present application;

[0034] Figure 5 It is a schematic diagram of the shunt installation for reducing the contact resistance in another embodiment of the present application;

[0035] Figure 6 It is a flow chart of the shunt fixing installation method for reducing the contact resistance in another embodiment of the present application.

[0036] Reference signs:

[0037] 10, shell; 100, fixing nut; 101, avoiding space; 102a, first fixing part; 102b, second fixing part;

[0038] 2, conductive hard bar; 20, pressure rivet nut; 21, first copper bar; 22, second copper bar; 210, first through hole;

[0039] 220, second through hole; 211, first preset hole; 221, second preset hole; 213, third through hole; 223, fourth through hole; 214, first copper bar external connection point; 224, second copper bar external connection point;

[0040] 3, shunt; 31, first connecting hole; 32, second connecting hole;

[0041] 4. A bolt. DETAILED DESCRIPTION

[0042] The technical solutions of the present application will be described below in conjunction with the drawings to make the technical solutions of the present application clear and complete, and the drawings attached to the specification serve to provide further understanding of the present application. The illustrative embodiments of the present application and the description are used to explain the present application and do not constitute an improper limitation on the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0043] It should be noted that, unless otherwise defined or limited, the up, down, left, right and other directions referred to in the present application are based on the up, down, left, right and other directions shown in the embodiments of the present application. If the specific posture changes, the directional indications also change accordingly. The terms "first", "second" and similar terms used in the present application do not represent any order, number or importance, but are only used to distinguish different components. In addition, in various embodiments of the present application, the same or similar reference numerals represent the same or similar components. Figure 2

[0044] In the present application, unless otherwise defined or limited, the terms "connection", "fixation" and the like should be understood broadly, for example, "connection" can be fixed connection, or detachable connection, or integral, unless otherwise defined or limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0045] In addition, the technical solutions of various embodiments of the present application can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can realize it. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection of the present application.

[0046] Embodiment one

[0047] Please refer to Figure 2 , Figure 3 In the present embodiment, a shunt fixing device for reducing contact resistance is shown. The fixing device includes a shell 10, a conductive hard row 2 and a shunt 3. The shunt 3 is provided with two first connecting holes 31 and two second connecting holes 32 at both ends respectively. The conductive hard row includes a preset hole fixedly connected with the shunt 3. The preset hole includes two first preset holes 211 corresponding to the two first connecting holes 31 and two second preset holes 221 corresponding to the two second connecting holes 32.

[0048] In conjunction with Figure 3 ​As shown, the conductive rigid busbar 2 in this embodiment includes a first copper busbar 21 and a second copper busbar 22 that are electrically connected to both ends of the shunt 3, respectively. The first preset hole 211 is provided on the first copper busbar 21, and the second preset hole 221 is provided on the second copper busbar 22. Further, a press-fit nut 20 is provided on the side of the first preset hole 211 and the second preset hole 221 away from the shunt 3.

[0049] It should be noted that the so-called setting of press-fit nuts on the side of the first and second preset holes away from the distributor means that, in order to Figure 2 Taking the up, down, left, and right directions as shown, the rivet nut 20 is firmly pressed into the first and second preset holes on the lower side of the conductive hard strip. This not only ensures the flatness of the contact surface between the conductive hard strip and the splitter, but also effectively allows the splitter 3 to be fixed on the conductive hard strip by passing the bolt 4 through the first connecting hole 31, the first preset hole 211, the second connecting hole 32, and the second preset hole 221. Furthermore, the nut of the rivet nut on the lower side of the conductive hard strip is placed in the clearance space 101 inside the housing, fully realizing the free fixation of the conductive hard strip and the splitter without any interference from external forces. This greatly improves the contact performance between the conductive hard strip and the splitter, thereby reducing the contact resistance value and ensuring that the contact resistance value of the two is within a certain threshold range, preventing technical problems that affect the overall driving experience due to excessive contact resistance value.

[0050] It should be further explained that the contact resistance value in this embodiment refers to the value used to evaluate whether the contact between the shunt and the conductive hard busbar is good. Whether there is external stress interference during the contact period directly affects the connection quality. Generally, the voltage drop at the contact loading point is tested by differential pressure analysis, and the contact resistance value is calculated by Ohm's law. The higher the contact resistance value, the greater the voltage drop across the contact resistance, and therefore the more heat is released at the contact point. If the temperature rises to a certain limit, the contact point will be damaged, causing the BMS of new energy vehicles to be forced to reduce the output power, thereby affecting the overall driving experience. Therefore, the importance of shunt solutions that reduce contact resistance value in the field of new energy vehicles is self-evident. Moreover, shunts in other application fields generally do not need to consider the contact resistance value issue, and there is no reference or inspiration for reducing contact resistance value. Therefore, it is really not easy for those skilled in the art to solve a solution for reducing contact resistance value.

[0051] In addition, it should be noted that the number of the first connecting hole 31, the second connecting hole 32, the first preset hole 211 and the second preset hole 221 in the embodiment is preferably but not limited to two, and can be more according to actual needs, for example, when the shunt is a small current with a specification of not more than 400A, the number of the connecting holes at both ends of the shunt is preferably two, that is, a double-hole fixing mode is adopted; when the shunt is a large current with a specification of not less than 500A, the number of the connecting holes at both ends of the shunt is preferably four or more, that is, a four-hole, six-hole, eight-hole or more hole fixing can be adopted, which is within the protection scope of the application.

[0052] As a preferred embodiment, as shown in Figure 4 The relief space 101 provided in the shell 10 of the embodiment is preferably but not limited to a cylindrical hole, and the hole diameter of the cylindrical hole is required to be greater than the maximum outer diameter of the exposed part of the press-in nut 20, so as to sufficiently guarantee that the connection of the shunt and the conductive hard bus is not interfered by any external force, greatly improve the contact performance of the two, and be beneficial to reduce the contact resistance, guarantee the normal output power of the BMS of the new energy vehicle, and improve the driving experience of the vehicle.

[0053] As a preferred embodiment, as shown in Figure 3 , Figure 5 The first copper bus 21 and the second copper bus 22 of the embodiment are respectively provided with a third through hole 213 and a fourth through hole 223 for fixing them on the shell 10 at one end close to the shunt 3, and the third through hole 213 and the fourth through hole 223 are diagonally arranged along the shunt, which can guarantee uniform stress during bolt fixing, and is beneficial to improve the contact performance and reduce the contact difference.

[0054] Further, as shown in Figure 4 The shell 10 in the embodiment is provided with a first fixing part 102a and a second fixing part 102b corresponding to the third through hole 213 and the fourth through hole 223, and the first fixing part 102a and the second fixing part 102b are press-in nuts in the shell, in combination with Figure 5 Two bolts are respectively screwed into the press-in nuts of the first fixing part 102a and the second fixing part 102b through the third through hole 213 and the fourth through hole 223, achieving diagonal and stable fixing of the conductive hard bus.

[0055] It should be noted that the conductive hard row in the embodiment is uniformly fixed by the first fixing part 102a and the second fixing part 102b arranged diagonally on the shell. Compared with the prior art shunt, the conductive hard row is fixed on the shell at the end away from the shunt, that is, fixed on the shell by the first copper row external connection point 214 and the second copper row external connection point 224, which greatly reduces the "seesaw effect" and is beneficial to achieving the beneficial effect of reducing the contact resistance.

[0056] Further, as shown in Figure 2 , Figure 5 In the embodiment, the copper row preset hole of the first copper row external connection point 214 and the second copper row external connection point 224 of the conductive hard row is pressed into a press-in rivet nut to achieve fixed connection with the external copper row, which eliminates the installation mode of having to be fixed on the shell to achieve press connection. Most importantly, the embodiment improves the installation connection mode at both ends of the conductive hard row, which can reduce the "seesaw effect" and achieve the beneficial effect of reducing the contact resistance.

[0057] As a preferred embodiment, the surface plating layer of the conductive hard row in the embodiment preferably adopts tin plating. In combination with the above-described installation connection mode of the conductive hard row at both ends of the embodiment, the beneficial effect of reducing the contact resistance can be better achieved. For specific effects, refer to the experimental test data table of the plating layer of the conductive hard row using nickel plating and tin plating in the following table:

[0058] Test value of the plating layer of the conductive hard row using nickel plating:

[0059]

[0060] Test value of the plating layer of the conductive hard row using tin plating in the embodiment:

[0061]

[0062] As can be seen from the test data of the multiple sets of pressure drop values and their average values, resistance values (i.e. contact resistance values) measured under the condition of different plating layers of the conductive hard row in the same shunt fixing device in the above table, the conductive hard row in the embodiment using tin plating can better achieve the beneficial effect of reducing the contact resistance.

[0063] Embodiment two

[0064] As shown in Figure 6 The embodiment provides a shunt fixing and installation method for reducing contact resistance, which comprises the following steps:

[0065] S10, tin plating is performed on the plating layer of the conductive hard row, and a press-in rivet nut is pressed into the first preset hole and the second preset hole of the conductive hard row away from the side of the shunt, and a press-in rivet nut is pressed into the preset hole at the connection point of the external copper row.

[0066] S20, placing the conductive hard discharge pressed into the rivet nut on the shell, and placing the rivet nut in the relief space provided in the shell;

[0067] S30, fixing the shunt on the conductive hard discharge by respectively passing the bolt through the first connecting hole, the first preset hole, and the second connecting hole, and the second preset hole;

[0068] S40, fixing the conductive hard discharge on the fixing column of the shell.

[0069] As a preferred embodiment, the step S30 of fixing the shunt on the conductive hard discharge specifically comprises:

[0070] S301, the bolt is screwed on the rivet nut in the first preset hole through the first connecting hole, and on the rivet nut in the second preset hole through the second connecting hole.

[0071] As a preferred embodiment, the step S40 of fixing the conductive hard discharge on the shell specifically comprises:

[0072] S401, the conductive hard discharge comprises a first copper bar and a second copper bar electrically connected to both ends of the shunt, and is fixed on the shell through the fixing holes provided on the first copper bar and the second copper bar and diagonally arranged relative to the shunt.

[0073] By using the technical scheme of the embodiment, the shunt is fixed on the conductive hard discharge by respectively passing the bolt through the first connecting hole, the first preset hole, and the second connecting hole, and the second preset hole, so that the shunt is freely fixed on the conductive hard discharge. Compared with fixing the hard discharge and the shunt on the shell, the influence of deformation stress on the contact performance is avoided, the contact performance of the conductive hard discharge and the shunt is greatly improved, the contact resistance between the two is ensured within a certain threshold range, and the technical problem of affecting the driving experience of the whole vehicle due to the excessive contact resistance is prevented.

[0074] Furthermore, the first connecting hole and the second connecting hole at both ends of the shunt, and the first preset hole of the first copper bar and the second preset hole of the second copper bar are all provided as at least two, so that when the shunt is fixed on the conductive hard discharge, diagonal uniform fixing bolts can be used, the contact stress between the shunt and the conductive hard discharge is more uniform, the contact performance of the conductive hard discharge and the shunt is improved, and the excessive contact resistance between the two is prevented from affecting the driving experience of the whole vehicle.

[0075] The foregoing description illustrates and describes the preferred embodiments of this application only, and it is not intended to be exclusive or exhaustive with respect to the application as claimed, as many modifications and variations thereof will become apparent to those skilled in the art upon reading the above description. It is intended to cover any and all modifications and variations coming within the scope of the present application as claimed. It is intended that the scope of the application claimed be limited only by the claims appended hereto and that the claims be interpreted not to be limited to the description or embodiments thereof set forth above.

Claims

1. A shunt fixing device for reducing contact resistance, characterized in that, include: The splitter has a first connection hole and a second connection hole respectively at its two ends; The conductive rigid busbar includes a pre-set hole that is fixedly electrically connected to the shunt. The pre-set hole includes a first pre-set hole corresponding to the first connection hole and a second pre-set hole corresponding to the second connection hole. The shunt is fixed on the conductive rigid busbar through the first connection hole, the first pre-set hole, the second connection hole, and the second pre-set hole. Wherein, press-fit nuts are provided on the side of the first preset hole and the second preset hole away from the distributor; The housing has an internal clearance space for avoiding the connection between the shunt and the conductive hard busbar. The clearance space is a cylindrical hole with a diameter larger than the maximum outer diameter of the press-fit nut. The conductive hard busbar is fixed to the housing. The conductive hard busbar includes a first copper busbar and a second copper busbar that are electrically connected to both ends of the shunt, respectively. The first pre-set hole is provided on the first copper busbar and the second pre-set hole is provided on the second copper busbar. The first copper busbar and the second copper busbar are respectively provided with a third through hole and a fourth through hole at one end near the shunt for fixing them to the housing, and the third through hole and the fourth through hole are arranged diagonally along the shunt.

2. The shunt fixing device for reducing contact resistance as described in claim 1, characterized in that, There are at least two of the first connecting hole, the second connecting hole, the first preset hole, and the second preset hole.

3. A shunt fixing installation method for reducing contact resistance, applied to the shunt fixing device for reducing contact resistance as described in claim 1 or 2, characterized in that, The method includes the following steps: S10. Press a rivet nut into the first and second preset holes of the conductive hard bar on the side away from the shunt. S20. Place the conductive hard busbar with the press-fit nut on the housing, and place the press-fit nut in the clearance space provided in the housing to avoid the connection between the shunt and the conductive hard busbar. S30. The shunt is fixed to the conductive rigid busbar by bolts passing through the first connecting hole, the first preset hole, the second connecting hole, and the second preset hole respectively. S40. Fix the conductive hard busbar to the housing; the conductive hard busbar includes a first copper busbar and a second copper busbar that are electrically connected to both ends of the shunt, and is fixed to the housing through fixing holes provided on the first copper busbar and the second copper busbar that are diagonally opposite to the shunt.

4. The shunt fixing installation method for reducing contact resistance as described in claim 3, characterized in that, Step S30, fixing the shunt to the conductive rigid busbar, specifically includes: S301, the bolt passes through the first connecting hole and is screwed onto the press-fit nut in the first preset hole, and passes through the second connecting hole and is screwed onto the press-fit nut in the second preset hole.

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