High working current sealing wiring terminal

Abstract

The utility model discloses a high working current sealing wiring terminal, which belongs to the field of wiring terminals and comprises a metal bottom plate, a conductive terminal, a sintering sealing element, a ceramic sheath and a bonding element. A plurality of through holes are formed in the metal bottom plate; the diameter of the conductive terminal ranges from 3.2 mm to 4.8 mm; the sintered sealing element has sealing and insulating effects and is positioned between the conductive terminal and the through hole of the metal bottom plate; the ceramic sheath is a hollow cylinder and is positioned below the sintering sealing element; and the bonding piece is positioned between the ceramic sheath and the through holes of the sintering sealing piece and the metal bottom plate. Compared with the prior art, the gas-tight connector can meet higher gas tightness and is more suitable for large-current working occasions.

Description

Technical Field

[0001] The utility model relates to the field of wiring terminals, in particular to a high working current sealed wiring terminal. Background Art

[0002] Terminal blocks are an accessory product used to achieve electrical connections and are widely used in the current industrial market. Sealed terminal blocks have waterproof, dustproof, and corrosion-resistant sealing properties. They are used to provide reliable connections in harsh environments, prevent moisture, dust, and chemicals from entering the connector, and protect the electrical contacts and circuits inside the terminal blocks from being affected by the external environment.

[0003] Refrigeration compressors are widely used in refrigeration industries such as air energy heat pump systems, air conditioning systems, and refrigerators. The working environment of refrigeration compressors is large current, and the conductive core of the sealed terminal in the prior art has a small diameter (about 3.2mm), which is suitable for low current occasions and cannot withstand the high working current of the refrigeration compressor.

[0004] It is well known in the art that for products of the same series, the thicker the pin, the greater the allowable working current. Therefore, the structure disclosed in "Sealed Terminal Block" (CN202320288624.2) can make the diameter of the conductive core within the range of 5mm-7mm, which is suitable for occasions with high working current (electric vehicles). However, the sealing and oil resistance of the compressor power terminal are very high, and when the diameter of the conductive core steel needle is thickened in order to increase its current resistance, the disadvantage of reduced airtightness will occur.

[0005] In addition, the existing terminal conductive core diameter models are concentrated in 3.2mm and 4.8mm. If the conductive core diameter is doubled, the docking components must also be changed. In addition, the steel needle is thickened. In order to ensure the distance between the steel needle and the base plate and the distance between adjacent steel needles, the metal base plate specifications and through-hole settings must be adaptively adjusted. The increased metal base plate specifications must match the new sintering template, and during assembly, the card slot structure of the assembly components must also be changed. The changes in the above specifications reduce market competitiveness. If the metal base plate specifications and through-hole settings are not changed, the conductive core that is more than doubled in thickness is sintered in the original through-hole specifications, the sealing insulation layer becomes relatively thinner, and pores are prone to occur during sintering. The glass body cracks caused by the temperature difference and expansion coefficient between the glass beads and the ceramic sheath, and the airtightness defects lead to poor insulation of the whole machine at high voltage, especially for compressors with high requirements for sealing and oil resistance.

[0006] Therefore, the market is in urgent need of a sealed terminal block with a specification of 3.2 to 4.8 mm suitable for high current working environments, and the air tightness meets the connection requirements of special chemical-resistant explosion-proof electrical appliances. Utility Model Content

[0007] The technical task of the utility model is to provide a high working current sealed terminal block in view of the deficiencies of the above existing technologies. This 3.2-4.8mm specification sealed terminal block can meet higher air tightness, is more suitable for high current working occasions, and is easy to disassemble and assemble to match more conductive systems and special needs of chemical-resistant explosion-proof electrical appliances and other connection terminals.

[0008] The utility model solves the technical problem by a technical solution: a high working current sealed terminal, comprising a metal base plate, a conductive terminal, a sintered seal, and a ceramic sheath, characterized in that: it also comprises an adhesive; a plurality of through holes are arranged on the metal base plate; the number and arrangement of the conductive terminals are the same as the number of through holes of the metal base plate, and the diameter range is 3.2 to 4.8 mm; the sintered seal has a sealing and insulating function, and is located between the conductive terminal and the through holes of the metal base plate; the ceramic sheath is a hollow cylinder, and is located below the sintered seal; the adhesive is located between the ceramic sheath and the sintered seal and the through holes of the metal base plate.

[0009] The conductive terminal is a steel needle.

[0010] The through hole is a countersunk hole, and the inner diameter of the upper part is larger than the inner diameter of the lower part.

[0011] The length of the upper portion of the countersunk hole is 20 to 33% of the total hole length.

[0012] The sintered sealing component is sintered and filled into the rear countersunk hole, with the upper end being higher than the level of the metal bottom plate and the lower end being located in the lower part of the countersunk hole.

[0013] The sintered seal is a sinterable glass bead.

[0014] The outer diameter of the upper opening of the ceramic sheath is smaller than the outer diameter of the lower opening, and the small outer diameter portion is located in the through hole of the metal bottom plate.

[0015] The adhesive is a mixture of epoxy resin glue and a hardener.

[0016] The adhesive layer formed by the adhesive member has a thickness of more than 1.00 mm.

[0017] Compared with the prior art, the utility model has the following outstanding beneficial effects:

[0018] 1. The insulation withstand voltage parameter of the 3.2-4.8mm specification product of the utility model is increased to 50,000 megohms, which is more suitable for working occasions with large currents;

[0019] 2. The utility model avoids the problem of glass cracks caused by the temperature difference and expansion coefficient difference between the glass beads and the ceramic sheath, and increases the air tightness, making it suitable for use in electrical connection terminals with more requirements for chemical resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the utility model.

[0021] Figure 2 It is a schematic diagram of the structure of the control group.

[0022] Figure 3 The digitized radiographic image of the control group 1 shows bubbles.

[0023] Figure 4 This is a crack in the digitized radiographic image of control group 1. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments of the specification. In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0025] In the following embodiments, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present utility model application can be understood according to the specific circumstances.

[0026] In order to better describe the Figure 1 It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", "end", "side" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the utility model application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the utility model application.

[0027] like Figure 1 As shown, the utility model is a high working current sealed terminal, comprising a metal base plate, a conductive terminal, a sintered seal, a ceramic sheath and an adhesive.

[0028] The metal bottom plate has a mounting and fixing support function, and a plurality of through holes are provided on the metal bottom plate. In the optimization scheme, the through hole is a countersunk hole, the upper inner diameter is larger than the lower inner diameter, and the upper length is 20-33% of the total hole length. In a specific embodiment, the upper length is 1.0-1.3mm, and the total length is 4.3mm. The lower inner diameter is the same as the prior art, and the hole diameter is 9-11mm. In this embodiment, the lower inner diameter is 9mm, which is 2.7 times the diameter of the conductive terminal.

[0029] The number and arrangement of the conductive terminals are the same as the number of through holes in the metal bottom plate, and have a conductive function; their diameter ranges from 3.2 to 4.8 mm. In this embodiment, the conductive terminals are specifically steel needles.

[0030] The sintered seal has a sealing and insulating function and is located between the conductive terminal and the through hole of the metal base plate. The sintered seal is sintered and filled into the rear countersunk hole, and the upper end is higher than the level of the metal base plate, and the lower end is located in the lower part of the countersunk hole. In this embodiment, the sintered seal is a sinterable glass bead. The ceramic sheath has insulating, heat-insulating and liquid buffering functions. It is a hollow cylinder and is located below the sintered seal. The outer diameter of the upper mouth is smaller than the outer diameter of the lower mouth, and the small outer diameter part is located in the through hole of the metal base plate. In the optimization scheme, the height of the ceramic sheath is 5-10mm, and the thickness (lower mouth outer diameter) is 8.5-13mm.

[0031] The adhesive is located between the ceramic sheath and the sintered seal and the through hole of the metal bottom plate, and has a sealing, insulating and bonding function. In this embodiment, the adhesive is epoxy resin glue, and the thickness of the glue layer is more than 1.00 mm.

[0032] The number and arrangement of the conductive terminals and the safe distance between the terminals are in accordance with the electrical design specifications in the prior art; the thickness of the ceramic sheath is determined by reference to the diameter and withstand voltage requirements of the conductive terminal steel needle. The selection of the above parameters is all in the prior art and will not be repeated here.

[0033] The utility model eliminates the problem of bubble cavities inside the product, avoids a series of problems caused by the re-sintering process of the assembly, avoids the breakage caused by collision between products due to the nickel plating process, increases the yield rate in the actual production process, and improves the product quality.

[0034] In order to better compare the process method of this application with the prior art, a comparative test was conducted. In order to ensure consistent baselines, the specifications of the conductive terminals, metal base plates and ceramic sheaths used are consistent, and the existing product specifications are used: the metal base plate aperture is 11mm, and the ceramic sheath height is 9.2mm. The amount of glass seals used is the same, and the height of the glass protrusion after sintering is 1mm. The sintered seals used in the process are all glass beads sintered, and the amount used is so that the height of the glass protrusion after sintering reaches 1.5mm, the sintering temperature is 945℃, and the sintering time is 3h.

[0035] The embodiment group adopts the structure and production process of the utility model, the conductive terminal has a diameter of 4.8 mm, the preheating temperature is 80° C., the preheating time is 60 min, the vacuum time after glue filling is 5 min, the hardening temperature is 160° C., and the hardening time is 8 h.

[0036] Control group 1 is the product currently produced and sold by the company, with a structure such as Figure 2 As shown, it includes a conductive terminal, a metal base plate, a glass seal and a ceramic sheath, and the metal base plate has multiple straight holes. The preparation process is: put the conductive terminal, the metal base plate and the ceramic sheath into the sintering template, and then put the glass beads between the conductive terminal and the through hole of the metal base plate, above the ceramic sheath. During production, the above components are assembled and put into the mold, and automatically sintered through the sintering furnace conveyor belt, so that the glass beads melt and flow in liquid when passing through the high-temperature furnace section, and the steel needle is welded with the metal base plate and the ceramic sheath, and then cooled and formed. After sintering and forming, the product is surface treated by chemical nickel plating process to become a finished product. The finished product is inspected for silicone oil air tightness, insulation resistance, and appearance.

[0037] The conductive terminal diameter of control group 2 is 6 mm, and the rest of the structure and process are the same as those of control group 1.

[0038] In the digital radiographic examination of each group, the control group Figure 3 , showing that bubbles generated during the sintering process of the glass bead sintering layer and the ceramic sheath cannot be discharged (the arrow points to the bubble area), resulting in poor voltage resistance of the product. Figure 4 It shows that after sintering, the control group had glass cracks (the annular area indicated by the arrow) due to the temperature difference and expansion coefficient between the glass beads and the ceramic sheath, resulting in poor airtightness. However, the X-ray equipment of each embodiment group had no bubbles or glass cracks.

[0039] In the airtightness inspection of each group, "no leakage for 1 minute under a nitrogen pressure of 2.0 to 2.2 MPa" was used as the qualification standard. The qualification rates of each group in the embodiment and the control group 1 were 100%, while the qualification rate of the control group 2 was 95%. The reason for this is that the sealing insulation layer is relatively thin, pores are easily formed during sintering, and the glass cracks are caused by the temperature difference and expansion coefficient between the glass beads and the ceramic sheath.

[0040] In the insulation resistance inspection of each group, each group of the embodiment can withstand a maximum current of 50A, a maximum withstand voltage of 5000V, and an insulation resistance of 50000MΩ (1000V), while the control group 1 can withstand a maximum current of 20A, a maximum withstand voltage of 3000V, and an insulation resistance of 10000MΩ (1000V); the control group 2 can withstand a maximum current of 30A and a withstand voltage of 500V, but the insulation resistance can only reach 3000MΩ (1000V), which may be due to the following aspects: foreign matter enters the sintering joint between the glass beads and the ceramic sheath of the control group 1-2 (such as dust in the furnace, etc.), resulting in poor product performance; after sintering, the product enters the chemical nickel plating process, and friction and collision occur during the nickel plating of the product, resulting in the ceramic sheath breaking and falling off; in the chemical nickel plating process, chemicals are easily entered into the ceramic gaps, and the cleaning is not thorough, resulting in poor insulation. Moreover, in the control group 2, under the existing metal base plate specifications, the insulating layer is too thin due to the increase in the diameter of the conductive terminal, resulting in a maximum withstand voltage of only 500V.

[0041] It can be seen from the above results that the process and product of the utility model solve the drawbacks of sintering pores, etc. The product can be used for a long time and the insulation withstand voltage is stable; it avoids the friction and collision during the nickel plating of the product that causes the ceramic sheath to break and fall off; it prevents foreign matter from entering the ceramic sheath during sintering, resulting in poor insulation; and it solves the problem of poor air tightness caused by glass cracks due to the temperature difference and expansion coefficient between the glass beads and the ceramic sheath. The sealed terminal obtained by the utility model is more suitable for high voltage and high current working occasions, such as: air conditioning compressors: refrigeration refrigerator compressors, new energy vehicle air conditioning compressors. And its better air tightness makes it suitable for use in more chemical-resistant electrical connection terminals.

[0042] It should be noted that matters not described in detail in this embodiment are well-known technologies in the art.

[0043] The above description is only for the purpose of describing the present invention in detail for the specific implementation purpose of the present invention. For those skilled in the art, various obvious changes made to the present invention without departing from the spirit and scope of the present invention are within the protection scope of the present invention.

Claims

1. A high working current sealed terminal, comprising a metal base plate, a conductive terminal, a sintered seal, and a ceramic sheath, characterized in that: It also includes an adhesive; a plurality of through holes are provided on the metal base plate; the number and arrangement of the conductive terminals are the same as the number of through holes of the metal base plate, and their diameters range from 3.2 to 4.8 mm; the sintered seal has a sealing and insulating function and is located between the conductive terminals and the through holes of the metal base plate; the ceramic sheath is a hollow cylinder and is located below the sintered seal; the adhesive is located between the ceramic sheath and the sintered seal and the through holes of the metal base plate.

2. The high operating current sealed terminal according to claim 1, characterized in that: The conductive terminal is a steel needle.

3. The high operating current sealed terminal according to claim 1, characterized in that: The through hole is a countersunk hole, and the inner diameter of the upper part is larger than the inner diameter of the lower part.

4. The high operating current sealed terminal according to claim 3, characterized in that: The length of the upper portion of the countersunk hole is 20 to 33% of the total hole length.

5. The high operating current sealed terminal according to claim 3, characterized in that: The sintered sealing component is sintered and filled into the rear countersunk hole, with the upper end being higher than the level of the metal bottom plate and the lower end being located in the lower part of the countersunk hole.

6. The high operating current sealed terminal according to claim 1, characterized in that: The sintered seal is a sinterable glass bead.

7. The high operating current sealed terminal according to claim 1, characterized in that: The outer diameter of the upper opening of the ceramic sheath is smaller than the outer diameter of the lower opening, and the small outer diameter portion is located in the through hole of the metal bottom plate.

8. The high operating current sealed terminal according to claim 1, characterized in that: The adhesive layer formed by the adhesive member has a thickness of more than 1.00 mm.

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