A cable connector and a DC-DC converter including the connector

Abstract

The present invention relates to a current connector device, and in particular to a cable connector and a DC-DC converter including the connector. The device comprises a fixed terminal, the fixed terminal having a central through hole penetrating the fixed terminal, one end of a cable entering the central through hole from one end of the central through hole, the other end of the cable being located outside the central through hole of the fixed terminal, an injection molding body being arranged between the inner wall of the central through hole of the fixed terminal and the outer wall of the cable, the injection molding body abutting and sealing against the inner wall of the central through hole of the fixed terminal, the injection molding body abutting and sealing against the outer wall of the cable, the end of the cable entering the central through hole of the fixed terminal being electrically led out directly or indirectly from the position of the injection molding body corresponding to the other end of the central through hole to form an electrical lead-out terminal.

Description

Technical Field

[0001] The invention relates to a current connector device, in particular to a cable connector and a DC-DC converter comprising the connector. Background Art

[0002] With the rapid development of electric vehicle technology, the position of DCDC converter in the field of new energy electric vehicles is particularly important. With the increase of power consumption in pure electric vehicles, the output current of DCDC converter as the power supply equipment of the whole vehicle must also increase (DCDC converter is a standard low-voltage output device). This requires a current connection device that can carry large current and match the aluminum shell of the converter to achieve waterproof sealing.

[0003] There are two types of high-current connectors on the current market. One is: using a copper rod as a conductive carrier, with threaded holes on both sides of the copper rod, and the middle of the copper rod is mostly a plastic body made of injection-molded nylon. This structure is collectively referred to as the positive output terminal. The terminal is fixed to the aluminum shell with screws through the holes in the plastic body. The terminal and the aluminum shell are usually sealed with a silicone rubber gasket for waterproofing. The copper rod on one side of the terminal (inside the aluminum shell) is tightly connected to the conductive copper strip by screws, and the copper rod on the other side is tightly connected to the copper nose that can carry a large current by screws. Of course, for the safety of electric vehicle maintenance, protective devices (such as protective covers) need to be added to the outside of the terminal to avoid touching the exposed copper nose and copper rod. This device is connected by two screw presses, which will inevitably lead to an increase in resistance. If the screws are loose after a long time, the resistance will increase sharply, reducing the efficiency of the entire vehicle, and there may also be a risk of overheating and fire; the protective device on the outside of the terminal increases the complexity of the overall structure, which not only increases the manufacturing cost, but also reduces the installation efficiency.

[0004] Another method is to inject a structure made of the same material as the outer skin of the wiring harness (mostly PVC) on the wiring harness. This structure and the wiring harness are collectively called "swing wire". The swing wire is fixed to the aluminum shell with screws. Rubber gaskets or CR gaskets are generally used between the two for waterproof sealing, and then fixed with screws. Because PVC material is soft at room temperature, its structure will be greatly deformed when screwed, so stainless steel sheets are generally pressed on the swing wire to ensure uniform stress on the structure and reduce deformation and damage. Regardless of whether this structure is added with steel sheets or not, after the structure has undergone "aging" (hot and cold cycles), the screws loosen and the waterproof seal fails. Summary of the invention

[0005] The purpose of the present invention is to provide a cable connector which can carry relatively high current, has good sealing performance and is easy to install, and a DC-DC converter including the connector, thereby solving the problems existing in the prior art.

[0006] The above technical purpose of the present invention is mainly solved by the following technical solutions: it includes a fixed terminal, the fixed terminal has a central through hole that penetrates the fixed terminal, one end of the cable enters the central through hole from one end of the central through hole, the other end of the cable is located outside the central through hole of the fixed terminal, an injection molding is arranged between the inner wall of the central through hole of the fixed terminal and the outer wall of the cable, the injection molding abuts and seals with the inner wall of the central through hole of the fixed terminal, the injection molding abuts and seals with the outer wall of the cable, the end of the cable entering the central through hole of the fixed terminal is directly or indirectly electrically led out from the position of the injection molding corresponding to the other end of the central through hole and forms an electrical lead-out terminal. The present invention arranges an injection molding between the fixed terminal and the cable to ensure a dense and reliable sealing effect between the cable and the fixed terminal. During installation, the cable connector of the present invention is fixed to the installation part by fixing the fixed terminal to the installation part, the fixed terminal is sealed to the installation part, and an installation hole or installation thread is formed on the outside of the fixed terminal for fixed connection with the installation part. The fixed terminal is preferably made of 30%-33% by weight of glass fiber reinforced PA66 nylon integrally injection molded. The reinforced PA66 nylon here is a mixed material with PA66 as the main material, 30%-33% by weight of glass fiber, a small amount of carbon fiber, mineral fillers, lubricants, antioxidants and other auxiliary materials added. The reinforced PA66 nylon is wear-resistant, high and low temperature resistant and has high mechanical strength; the injection molding body is preferably made of TPE material, which has good high and low temperature resistance.

[0007] Preferably, the end of the cable entering the central through hole of the fixed terminal is directly extended outside the injection molded body to realize electrical lead-out, so as to adapt to the use in occasions where the passing current is relatively small; when the passing current is relatively large, preferably, the end of the cable entering the central through hole of the fixed terminal is electrically connected to one end of the conductive part in the central through hole of the fixed terminal, and the other end of the conductive part is extended outside the injection molded body to realize electrical lead-out, and the connecting part between the conductive part and the cable is sealed and wrapped by the injection molded body.

[0008] Preferably, the connection end between the conductive member and the cable is formed with a bent portion, and the bent portion is sealed and wrapped by the injection molded body. The arrangement of the bent portion on the conductive member can enhance the axial fixing strength of the cable on the injection molded body, and prevent the cable from axially loosening and pulling off.

[0009] Preferably, the inner wall of the fixed terminal is provided with an inner protrusion, and the inner protrusion is embedded in the injection molded body. When the injection molding shrinks due to temperature reduction or the like, the inner protrusion embedded in the injection molded body can play a role of pulling and limiting the injection molded body to limit the radial shrinkage of the injection molded body, thereby ensuring the sealed contact between the injection molded body and the inner wall of the central through hole of the fixed terminal, thereby ensuring the sealing effect.

[0010] Preferably, the inner protrusion includes two annular inner protrusion arrays, and the two annular inner protrusion arrays are axially spaced a distance apart on the inner wall of the central through hole of the fixed terminal, and each annular inner protrusion array includes a plurality of inner protrusion monomers distributed in an annular manner. The inner protrusion monomers of the two annular inner protrusion annular arrays are mutually offset on the axial projection plane, thereby blocking the axial gap channel generated by the gap that may exist between the injection molding body and the inner wall of the central through hole of the fixed terminal, thereby further improving the sealing effect. By setting up two annular inner protrusion arrays, it is possible to ensure uniform sealing contact of the fixed terminal with the injection molding body at two axial locations, thereby ensuring double sealing between the inner wall of the central through hole of the fixed terminal and the injection molding body.

[0011] Preferably, the cross-sectional area of ​​at least one part of the inward convex monomer is larger than the cross-sectional area of ​​the root of the inward convex monomer. The inward convex monomer may be a frustum structure, or may be a structure with uneven surface, so as to enhance the tightening effect of the inward convex monomer on the injection molded body and avoid the loosening between the inward convex monomer and the injection molded body due to the shrinkage deformation of the injection molded body.

[0012] Preferably, the fixed terminal is formed with a step hole at one end corresponding to the electrical lead-out of the cable, the inner diameter of the step hole is larger than the diameter of the central through hole at the step hole adjacent to the central through hole and is coaxial with the central through hole, and the injection molded body is formed with an outer convex ring matching the inner diameter of the step hole, and the outer convex ring forms a seal with the step surface of the step hole. The cooperation between the outer convex ring of the injection molded body and the step surface of the fixed terminal can further ensure the sealing effect between the injection molded body and the fixed terminal.

[0013] Preferably, the thickness of the outer convex ring on the injection molding is less than the axial depth of the step hole, so that an annular groove for arranging a sealing ring is formed between the injection molding and the end face of the fixed terminal, and the end of the injection molding corresponding to the electrical lead of the cable axially protrudes from the end face of the fixed terminal to form an assembly convex portion. Among them, the sealing ring is arranged in the annular groove to facilitate the sealing between the fixed terminal and the installation part, and the assembly convex portion on the injection molding facilitates the matching installation of the connector and the installation part and enhances the sealing effect.

[0014] Preferably, the central through hole of the fixed terminal is composed of a plurality of inner hole segments with different inner diameters, and there is a step transition between adjacent inner hole segments. The steps between adjacent inner hole segments can limit the axial position of the injection molding body to limit the axial position stability of the injection molding body, thereby ensuring the sealing between the fixed terminal, the injection molding body and the cable.

[0015] The DCDC converter including the cable connector of the present invention comprises a housing, the housing is provided with a through hole for the electrical lead-out end of the cable to pass through, the fixed terminal is fixed to the housing, and the electrical lead-out end of the cable passes through the through hole into the housing to be electrically connected to the internal wiring terminal of the converter. The DCDC converter of the present invention adopts the cable connector of the present invention, so that it has the characteristics of good sealing and convenient installation.

[0016] Therefore, the present invention has the characteristics of good sealing effect, convenient installation, simple structure and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a cable connector of the present invention;

[0018] Figure 2 It is a three-dimensional schematic diagram of the fixed terminal;

[0019] Figure 3 It is a three-dimensional schematic diagram of the fixed terminal from another angle;

[0020] Figure 4 is a cross-sectional view of the fixed terminal;

[0021] Figure 5 It is a three-dimensional structural diagram of an injection molded body;

[0022] Figure 6 is another structural schematic diagram of the cable connector of the present invention;

[0023] Figure 7 yes Figure 6 sectional view of . DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0025] Embodiment 1:

[0026] like Figure 1 As shown, it includes a fixed terminal 1, the fixed terminal 1 has a central through hole 2 that penetrates the fixed terminal, one end of the cable 3 enters the central through hole 2 from one end of the central through hole, and the other end of the cable is located outside the central through hole of the fixed terminal. An injection molding body 4 is arranged between the inner wall of the central through hole 2 of the fixed terminal 1 and the outer wall of the cable 3. The end of the cable 3 that enters the central through hole of the fixed terminal directly extends to the outside of the injection molding body to realize electrical lead-out and form an electrical lead-out terminal 5, so as to adapt to occasions where the current is small; the injection molding body 4 abuts and seals with the inner wall of the central through hole 2 of the fixed terminal 1, and the injection molding body 4 abuts and seals with the outer wall of the cable 3. The inner wall of the fixed terminal 1 is provided with an inner protrusion 6, and the inner protrusion 6 is embedded in the injection molding body 4.

[0027] like Figure 2 , Figure 3 and Figure 4 As shown, the fixed segment forms a rectangular outer protrusion 8 on the outer wall, and the outer protrusion 8 is provided with four mounting holes 81 for fixing with a housing such as a DCDC converter, and the inner protrusion includes two annular inner protrusion arrays 61, and the two annular inner protrusion arrays 61 are axially spaced a distance from the inner wall of the central through hole of the fixed terminal, and each annular inner protrusion array 61 includes a plurality of inner protrusion monomers 611 uniformly spaced in an annular shape. The inner protrusion monomers 611 of the two annular inner protrusion annular arrays are mutually displaced on the axial projection plane, thereby blocking the axial gap channel generated by the gap that may exist between the injection molding body and the inner wall of the central through hole of the fixed terminal, thereby further improving the sealing effect. The cross-sectional area of ​​the inner protrusion monomer 611 is at least one place larger than the cross-sectional area of ​​the root of the inner protrusion monomer. In this embodiment, the inner protrusion monomer 611 adopts a frustum structure with a large cross-sectional area at the free end and a small cross-sectional area at the root, thereby enhancing the tightening effect of the inner protrusion monomer on the injection molding body, and avoiding the loosening between the inner protrusion monomer and the injection molding body due to the shrinkage deformation of the injection molding body. The central through hole of the fixed terminal is composed of a large inner hole section 21 and a small inner hole section 22 with different inner diameters. Two annular inner protrusion arrays 61 are respectively arranged on the inner wall of the large inner hole section 21 and the inner wall of the small inner hole section 22, and adjacent inner hole sections are transitioned by steps 23. Among them, the step between the large inner hole section 21 and the small inner hole section 22 can limit the axial position of the injection molding body to limit the axial position stability of the injection molding body, thereby ensuring the sealing between the fixed terminal, the injection molding body and the cable. A step hole 24 is formed at one end of the fixed terminal corresponding to the electrical lead of the cable. The inner diameter of the step hole 24 is larger than the diameter of the central through hole at the step hole adjacent to the central through hole and is coaxial with the central through hole. The inner wall of the step hole 24 is formed with four circumferentially evenly spaced ribs 241. As shown Figure 5 As shown, the injection molding body is formed with an outer convex ring 41 matching the inner diameter of the step hole, the outer convex ring 41 forms a seal with the step surface of the step hole, and the outer convex ring 41 is injection-molded with a concave portion 411 matching the convex rib 241 of the inner wall of the step hole 24 of the central through hole of the fixed terminal. The matching of the outer convex ring of the injection molding body and the step surface of the fixed terminal can further ensure the sealing effect between the injection molding body and the fixed terminal. Figure 1 As shown, the thickness of the outer convex ring 41 on the injection molding body is less than the axial depth of the step hole, so that an annular groove 242 for arranging a sealing ring is formed between the injection molding body and the end face of the fixed terminal, the O-ring 7 is in the annular groove 242 and partially protrudes from the annular groove 242, and the end of the injection molding body corresponding to the cable electrical lead axially protrudes from the end face of the fixed terminal to form an assembly convex portion 42. Arranging the sealing ring in the annular groove can facilitate the sealing between the fixed terminal and the installation part, while the assembly convex portion on the injection molding body facilitates the matching installation of the connector and the installation part and enhances the sealing effect.

[0028] When the injection molding shrinks due to temperature reduction or other conditions, the inner protrusion embedded in the injection molding body can pull and limit the radial shrinkage of the injection molding body to ensure the sealing contact between the injection molding body and the inner wall of the central through hole of the fixed terminal, thereby ensuring the sealing effect.

[0029] The injection molding body is arranged between the fixed terminal and the cable to ensure a dense and reliable sealing effect between the cable and the fixed terminal. During installation, the cable connector of the present invention is fixed to the installation part by fixing the fixed terminal to the installation part, and the fixed terminal is sealed and connected to the installation part. The fixed terminal is formed with a mounting hole or mounting thread on the outside for fixed connection with the installation part. The fixed terminal is injection molded with reinforced PA66 nylon containing 30%-33% by weight of glass fiber. The reinforced PA66 nylon here is a mixed material with PA66 as the main material, 30%-33% by weight of glass fiber, a small amount of carbon fiber, mineral fillers, etc., as well as auxiliary materials such as lubricants and antioxidants. The reinforced PA66 nylon material is wear-resistant, high and low temperature resistant, and has high mechanical strength; the injection molding body is preferably made of TPE material, which has good high and low temperature resistance. By setting two annular inner protrusion arrays, it can be ensured that the fixed terminal is in uniform sealing contact with the injection molding body at two axial locations, which plays a double sealing guarantee between the inner wall of the central through hole of the fixed terminal and the injection molding body.

[0030] Embodiment 2:

[0031] The difference from Example 1 is that Figure 6 and Figure 7 As shown, the end of the cable 3 entering the central through hole of the fixed terminal is electrically connected to one end of the conductive member 9 formed by the copper nose in the central through hole of the fixed terminal, and the other end of the conductive member extends outside the injection molding body 4 to realize electrical extraction, and the connection part between the conductive member 9 and the cable 3 is sealed and wrapped by the injection molding body 4. A bending portion 91 is formed at the connection end between the conductive member 9 and the cable 3, and the bending portion 91 is sealed and wrapped by the injection molding body 4. Among them, the setting of the bending portion 4 on the conductive member can enhance the axial fixing strength of the cable in the injection molding body, prevent the cable from axial loosening and pulling off.

[0032] The DCDC converter of the present invention needs to ensure safe use of a relatively large current. Figure 6 and Figure 7 As shown, it includes a shell 10, and the shell 10 is provided with a through hole 11 for the electrical lead-out end of the cable 3 to pass through. The fixed terminal 1 and the shell 10 are fixed by screws 12 so that the O-ring is pressed between the surface of the shell 10 and the outer convex ring 41 of the injection molding body 4 to form a seal between the terminal and the shell. The assembly convex part 42 of the injection molding body is matched in the through hole 11 of the shell. The electrical lead-out end of the cable passes through the through hole into the shell and is electrically connected to the internal terminal of the converter.

[0033] During assembly, press the rivet nut 13 onto the conductive part 9 formed by the copper nose, and then press the wire cable onto the tail of the conductive part 9. Then, pass the cable through the central through hole of the fixed terminal 1 and place it on the injection mold together, inject the injection molded body 4, and finally "stuck" the O-ring 7 into the annular groove 242 to obtain a cable connector. The installation of the entire connector is also relatively convenient: fix the fixed terminal 1 with a screw 12 with an M4 flat spring washer, and align the circular hole on the copper strip 15 connected to the circuit board with the conductive part 9 at the other end, install the flat washer 16, spring washer 17 and M6 bolt 18 in sequence, and tighten the bolt. The other structures of the DCDC converter of the present invention are conventional structures and are not described in detail here.

Claims

1. A cable connector, comprising a fixed terminal, characterized in that The fixed terminal has a central through hole that passes through the fixed terminal, one end of the cable enters the central through hole from one end of the central through hole, and the other end of the cable is located outside the central through hole of the fixed terminal, and an injection molded body is arranged between the inner wall of the central through hole of the fixed terminal and the outer wall of the cable, the injection molded body abuts and seals with the inner wall of the central through hole of the fixed terminal, the injection molded body abuts and seals with the outer wall of the cable, and the end of the cable entering the central through hole of the fixed terminal is directly or indirectly electrically led out from the position of the injection molded body corresponding to the other end of the central through hole to form an electrical lead-out end; the inner wall of the fixed terminal is provided with an inner protrusion, and the inner protrusion is embedded in the injection molded body; the inner protrusion includes two annular inner protrusion arrays, the two annular inner protrusion arrays are axially spaced a distance on the inner wall of the central through hole of the fixed terminal, and each annular inner protrusion array includes a plurality of inner protrusion monomers distributed in an annular manner; the central through hole of the fixed terminal is composed of a plurality of inner hole sections with different inner diameters, and there is a step transition between adjacent inner hole sections.

2. The cable connector according to claim 1, characterized in that The end of the cable entering the central through hole of the fixed terminal directly extends to the outside of the injection molded body to realize electrical extraction.

3. The cable connector according to claim 1, characterized in that The end of the cable entering the central through hole of the fixed terminal is electrically connected to one end of the conductive part in the central through hole of the fixed terminal, and the other end of the conductive part extends out of the injection molding body to realize electrical lead-out, and the connection part between the conductive part and the cable is sealed and wrapped by the injection molding body.

4. The cable connector according to claim 3, characterized in that A bending portion is formed at the connection end between the conductive member and the cable, and the bending portion is sealed and wrapped by the injection molded body.

5. The cable connector according to claim 1, characterized in that The cross-sectional area of ​​at least one part of the inwardly convex monomer is larger than the cross-sectional area of ​​the root of the inwardly convex monomer.

6. The cable connector according to claim 1 or 2 or 3 or 4, characterized in that A step hole is formed on the end of the fixed terminal corresponding to the cable electrical lead-out, the inner diameter of the step hole is larger than the diameter of the center through hole at the step hole adjacent to the center through hole and is coaxial with the center through hole; an outer convex ring matching the inner diameter of the step hole is formed on the injection molding body, and the outer convex ring forms a seal with the step surface of the step hole; the thickness of the outer convex ring on the injection molding body is smaller than the axial depth of the step hole, so that an annular groove for arranging a sealing ring is formed between the injection molding body and the end face of the fixed terminal, and an assembly convex portion is formed on the end of the injection molding body corresponding to the cable electrical lead-out, which protrudes axially from the end face of the fixed terminal.

7. A DCDC converter comprising a cable connector according to any one of claims 1 to 6, comprising a shell, the shell being provided with a through hole for the electrical lead-out end of the cable to pass through, the fixed terminal being fixed to the shell, the electrical lead-out end of the cable passing through the through hole into the shell to be electrically connected to the internal terminal of the converter.

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