Method for connecting pins of direct insertion type device

Abstract

The invention relates to a pin connection method, in particular to a pin connection method for a direct insertion type device, and solves the problems of high cost and no quantitative evaluation standard of connection quality in the prior art. The method comprises the following steps of: 1, adjusting the crimping pliers to a preset gear; 2, connecting the pins with the pin terminals; step 3, pulling-out force testing; if yes, executing step 7; if not, F is compared with F0; if F < F0, executing the step 4; f is larger than or equal to F0, the direct insertion type devices and the pin terminals of the same batch are taken again, the step 1 is executed again, and the preset gear is increased; step 4, taking the same batch of direct insertion type devices and the pin terminals again, cleaning and then connecting the direct insertion type devices and the pin terminals by using the crimping pliers of which the gears are adjusted; step 5, pulling-out force testing; if yes, executing step 7; if not, executing the step 6; 6, taking the same batch of direct insertion type devices and pin terminals again, enlarging the preset gear of the crimping pliers, connecting the devices and the pin terminals, and returning to the step 5; 7, inserting the pinhole terminals in a butt joint manner; and step 8, sleeving a thermal shrinkage protective sleeve.

Description

Technical Field

[0001] The invention relates to a lead connection method, in particular to a lead connection method for a plug-in type device. Background Art

[0002] Direct-plug packaging is a common appearance structure of electronic devices. When assembling, the electrical interconnection between the lead and the circuit is generally achieved by directly welding the lead through a hole or connecting the lead with a wire. However, in some special application fields, such as application fields where direct-plug devices are required to have the function of emitting light in a special spectral band, the material of the lead of the direct-plug device in this application field is mostly a special metal material with poor welding wettability, which is difficult to form and has poor plasticity. The electrical interconnection between the lead and the circuit cannot be achieved by directly welding the lead through a hole or connecting the lead with a wire. For the electrical interconnection of direct-plug devices in this application field, the traditional method is to achieve electrical interconnection by tightening and squeezing the lead through a TC-type terminal screw. Although this method can achieve electrical interconnection, its connection contact surface is narrow and it is a point connection. It is easy to loosen due to external force, and its high-voltage electrical performance is poor and the contact resistance is large. In addition, its assembly process is complicated, the connector of the component is large in size, not easy to transport and assemble, and the plug-in and replacement interchangeability is also poor. In addition, there is no quantitative evaluation standard for its connection quality and the connection stability is missing.

[0003] In order to solve the above problems and meet the high reliability requirements of aerospace products, one of the existing solutions is to re-plate the lead legs of the through-hole device made of special metal materials with a solderable layer, and then realize the electrical interconnection between the lead legs and the circuit by directly welding the lead legs through holes or connecting them with wires. Although this solution fundamentally solves the problem, its cost is very high, and the cost of plating materials and processes even exceeds the value of the through-hole device itself. Another solution is to perform anti-loosening treatment on the screws, potting and reinforcing the joints, fixing the wires, etc., to enhance the connection firmness of the electrical interconnection achieved by tightening and extruding the lead legs with the TC-type terminal screws. This solution is a traditional practice of aerospace technology and can be applied within a certain range, but its cost is high, space requirements are strict, and the process route is complex, and it cannot be applied in large-scale engineering projects. In addition, there is currently also a closed point extrusion method that connects the lead of the plug-in type device with the closed point extrusion end of the pin terminal in the closed pit pressure terminal, and then the plug-in connection end of the pin terminal connected to the lead is plugged into the plug-in connection end of the hole terminal in the closed pit pressure terminal connected to the wire, and the external electrical interconnection is achieved through the wire connected to the hole terminal; however, when using crimping pliers for closed point extrusion connection, the gear position of the crimping pliers is generally adjusted through experience to control the extrusion force of the crimping pliers. It is difficult to make the extrusion force appropriate, which can easily cause insufficient extrusion force and loose connection, or damage the extrusion point of the lead and pin terminals due to excessive extrusion force, which can cause the lead and pin terminals to detach or be damaged and broken during use. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of high-reliability electrical interconnection between the pins of a through-hole device whose pins are made of special metal materials with poor welding wettability and a circuit, but the existing technology has the technical problems of high cost, large size of connectors, complex process routes, poor electrical performance and interchangeability, no quantitative evaluation standards for connection quality, and lack of connection stability, and to provide a through-hole device pin connection method.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for connecting lead legs of a through-hole device is used for connecting lead legs of a through-hole device with a length greater than or equal to 10 mm. The method is special in that it comprises the following steps:

[0007] Step 1: Adjust the gear of the crimping pliers to the preset gear;

[0008] Step 2: Use the crimping pliers adjusted to the correct position in step 1 to connect the lead leg of the plug-in device to the closed point extrusion end of the pin terminal in the closed pit crimping terminal by closed point extrusion;

[0009] Step 3: Perform a pull-off force test on the lead leg and pin terminal connected as one in step 2;

[0010] If the pull-off force test value F reaches the preset pull-off force value F0, and the connection between the lead leg and the pin terminal is not broken, the test is judged to be qualified, and step 7 is executed;

[0011] If the pull-off force test value F does not reach the preset pull-off force value F0, the connection between the lead leg and the pin terminal is broken, the test is judged to be unqualified, and the pull-off force test value F1 at the time of the break is recorded, and then the difference △F obtained by F0-F1 is compared with the preset pull-off force difference threshold △F0: if △F<△F0, execute step 4; if △F≥△F0, re-take the same batch of direct-insert type devices and pin terminals in the closed pit crimping terminals whose lead legs have not been connected, then return to step 1, and increase the preset gear of the crimping pliers;

[0012] Step 4: Re-take the same batch of direct-insert type devices and the pin terminals of the closed pit crimping terminals whose lead legs have not been connected, clean the lead legs of the direct-insert type devices and the pin terminals first, and then use the crimping pliers adjusted to the gear position in step 1 to connect the lead legs of the direct-insert type devices with the closed point extrusion end of the pin terminal through a closed point extrusion method;

[0013] Step 5: Perform a pull-off force test on the lead leg and pin terminal connected as one;

[0014] If the pull-off force test value F reaches the preset pull-off force value F0, and the connection between the lead leg and the pin terminal is not broken, the test is judged to be qualified, and step 7 is executed;

[0015] If the pull-off force test value F does not reach the preset pull-off force value F0, the connection between the lead leg and the pin terminal is broken, and the test is judged to be unqualified, and step 6 is executed;

[0016] Step 6: Re-take the same batch of direct-insert type devices and the pin terminals in the closed pit crimping terminal whose lead legs have not been connected, and increase the preset gear of the crimping pliers, connect the lead legs of the direct-insert type device with the closed point extrusion end of the pin terminal through the closed point extrusion method, and then return to step 5;

[0017] Step 7: Plug and connect the plug-in connection end of the pin terminal connected to the lead leg with the plug-in connection end of the hole terminal of the closed pit pressure terminal connected to the wire to form a matching point;

[0018] Step 8: After the connection in step 7, put a heat shrink protective cover on the entire outside of the pin terminal and the hole terminal, and use a hot air blower to shrink the heat shrink protective cover so that it shrinks and sticks to the outer surface of the pin terminal and the hole terminal. After wrapping the whole, let it stand for 10 minutes to 20 minutes to complete the connection between the lead legs of the direct plug-in device and the wire.

[0019] Furthermore, in order to make the extrusion force during connection appropriate and save test time and test cost when the lead legs of the same batch of through-hole type devices are electrically interconnected to the outside, the through-hole type device lead leg connection method of the present invention preferably also includes step 9, connecting the lead legs of other through-hole type devices in the same batch whose lead legs have not been connected to the corresponding wires, specifically:

[0020] Step 9.1: Connect the lead legs of other through-hole devices of the same batch that have not been connected yet to the closed point extrusion end of the pin terminal of the corresponding closed pit crimping terminal by using the crimping pliers that have been adjusted to the gear position for the last time;

[0021] Step 9.2: Use the method of steps 7 to 8 to complete the connection between the pins of other through-hole devices in the same batch whose pins have not been connected and the corresponding wires.

[0022] Furthermore, in order to make the connection more secure under the same gear condition of the crimping pliers, the specific operation method of the closed point extrusion method is as follows:

[0023] Step A: Place the pin terminal in the closed pit crimping terminal into the jaws of the crimping pliers, and make the pin terminal reach the bottom of the positioner on the crimping pliers so that the pin terminal and the positioner are well matched;

[0024] Step B: insert the lead of the through-hole device into the pressure hole of the pin terminal that matches the positioner well in step A until it touches the bottom, and ensure that the lead of the through-hole device can be seen from the observation port of the pin terminal;

[0025] Step C: Operate the crimping pliers to perform a closed point squeezing operation to form a squeezing point and complete the operation.

[0026] Furthermore, in order to find out the reason why the pull-off force test fails as soon as possible, the preset pull-off force difference threshold ΔF0 is (20% to 25%) F0.

[0027] Furthermore, in order to ensure reliable connection, convenient procurement and low cost, the closed pit pressure terminal uses J599 type closed terminal 22D#.

[0028] Furthermore, in order to have good contact resistance and excellent electrical performance, the needle terminal and the hole terminal in the J599 type closed terminal 22D# are both made of copper material as the internal base material and gold-plated material as the outer wrapping layer.

[0029] Furthermore, the model of the crimping pliers is M22520 / 2-01, and the model of the positioner installed on the crimping pliers is K42.

[0030] Furthermore, when performing the pull-off force test, a pull-off force tester is used to perform the pull-off force test;

[0031] When the preset pull-off force value F0 is within the range of 34N to 40N, the initial value of the preset gear in step 1 is gear 2, and the preset pull-off force difference threshold ΔF0 is 8N.

[0032] In this way, when the preset pull-off force value F0 is within the range of 34N to 40N, the gear position of the crimping pliers is initially adjusted to gear 2 in step 1, which will not cause damage to the lead legs of the through-hole device, and can make the pull-off force that can be sustained after the connection as close as possible to or meet the requirements of the preset pull-off force value F0; setting the preset pull-off force difference threshold △F0 to 8N can find out the reason for the failure of the pull-off force test as soon as possible, reducing the number of attempts required to determine the appropriate gear position of the crimping pliers.

[0033] Furthermore, in order to ensure that the heat shrinkable protective sleeve is firmly adhered to the outer surface of the pin terminal and the hole terminal after heat shrinkage, and can wrap the pin terminal and the hole terminal as a whole, protect the entire structure from external force and meet the requirements of moisture resistance, salt spray resistance, and mildew resistance, in step 8, the heat shrinkable protective sleeve adopts a transparent heat shrinkable protective sleeve with a diameter of 2mm to 3mm;

[0034] After the heat shrink protective sleeve is put on the outer part of the pin terminal and the hole terminal after the plug-in connection, the two ends of the heat shrink protective sleeve are respectively extended by 2mm to 4mm from the two ends of the outer part of the pin terminal and the hole terminal after the plug-in connection;

[0035] When a hot air blower is used to shrink the heat shrink protective sleeve, the heat shrink temperature is 120℃±5℃, and the heat shrink time is 10S~15S.

[0036] Furthermore, in order to shrink quickly after being heated, the transparent heat shrinkable protective sleeve is made of polyolefin.

[0037] The beneficial effects of the present invention are:

[0038] (1) The method for connecting the lead legs of a plug-in device of the present invention connects the lead legs of the plug-in device to the closed point extrusion end of the pin terminal in the closed pit pressure terminal by a closed point extrusion method, and then performs a pull-out force test on the lead legs and pin terminals connected as one; when the test fails, according to the relationship between the difference △F obtained by subtracting the pull-out force test value F1 at the time of fracture from the preset pull-out force value F0 and the preset pull-out force difference threshold △F0, it is determined whether to use the method of first cleaning, and if it is still unqualified after cleaning, then adjusting the position of the crimping pliers, or directly using the method of adjusting the position of the crimping pliers, so as to overcome the failure of the pull-out force test until the pull-out force test passes; then, the plug-in connection end of the pin terminal connected to the lead legs that passes the pull-out force test is plug-connected with the plug-in connection end of the hole terminal in the closed pit pressure terminal connected to the wire; finally, a heat shrink protective sleeve is set on the entire outside of the pin terminal and the hole terminal after the plug-in connection, and the electrical interconnection of the lead legs of the plug-in device to the outside is realized through the wire connected to the hole terminal;

[0039] When the direct-insert device lead leg connection method of the present invention is adopted to solve the problem of high-reliability electrical interconnection between the lead legs of a direct-insert device made of a special metal material with poor welding wettability and a circuit, there is no need to re-plating the lead legs with a solderable layer, nor is there any need to use TC-type terminal screws to tighten and extrude the lead legs to achieve electrical interconnection. Therefore, it avoids the very high cost problem caused by re-plating the lead legs with a solderable layer, and also avoids a series of problems caused by increasing the connection firmness, such as the need to perform anti-loosening treatment on the screws, potting and reinforcing the joints, and fixing the wires when using TC-type terminal screws to tighten and extrude the lead legs to achieve electrical interconnection. At the same time, the direct-insert device lead leg connection method of the present invention is superior to the traditional closed point extrusion method to achieve direct-insert device lead legs. For external electrical interconnection, the gear position of the crimping pliers is first adjusted to a preset gear position. The initial value of the preset gear position of the crimping pliers is given based on experience and is usually relatively low, so that the extrusion points of the lead legs and the pin terminals will not be damaged due to excessive extrusion force. Then, when the pull-off force test fails, different methods are used to overcome the failure of the pull-off force test according to the relationship between the difference △F obtained by subtracting the pull-off force test value F1 at the time of fracture from the preset pull-off force value F0 and the preset pull-off force difference threshold △F0, until the pull-off force test passes. Therefore, the direct-insert device lead leg connection method of the present invention can avoid the final product from being disconnected or damaged and broken due to insufficient extrusion force, or the extrusion point of the lead legs and the pin terminals being damaged due to excessive extrusion force.

[0040] To sum up, the direct-insert device lead leg connection method of the present invention gets rid of the traditional complex assembly process and its components, can realize quick connection, and improves the connection efficiency; when connecting, the closed pit-pressed terminal is used, which is several times smaller than the traditional TC-type terminal, and has a good space advantage; in addition, when connecting, the connection is made through a crimping pliers ring extrusion connection, which is a surface connection, with high connection reliability and good high-voltage electrical performance; furthermore, the closed pit-pressed terminal maturely used in aerospace is used for connection, which makes full use of the pin and hole characteristics of the terminal, and the terminal type can be freely selected to achieve free plugging and unplugging, with good terminal interchangeability and low cost; in addition, during the connection process, the reliability of the connection is detected by a pull-off force test, and the firmness of the connection can be quantitatively evaluated; therefore, the present invention solves the technical problems that the prior art solves the problem of high-reliability electrical interconnection between the lead legs of direct-insert devices and circuits whose lead legs are made of special metal materials with poor welding wettability, but has high cost, large connector volume, complex process route, poor electrical performance and interchangeability, and no quantitative evaluation standard for connection quality and lack of connection stability. By adopting the through-hole device lead connection method of the present invention, high-reliability and high-stability electrical interconnection between the through-hole device lead made of a special metal material with poor welding wettability and a circuit can be achieved.

[0041] (2) The method for connecting the lead legs of the through-hole device of the present invention preferably also includes step 9, connecting the lead legs of other through-hole devices of the same batch that have not yet been connected with the corresponding wires. In this way, when the lead legs of the through-hole devices of the same batch are electrically interconnected to the outside, the first lead leg of the through-hole devices of the same batch that is electrically interconnected to the outside will be tested for pull-out force after the connection with the pin terminal is completed, and the test is used to determine whether it is necessary to adjust the gear position of the crimping pliers; after the gear position of the crimping pliers is adjusted appropriately, when the lead legs of other through-hole devices of the same batch are electrically interconnected to the outside, there is no need to perform a pull-out force test; therefore, when the through-hole device lead leg connection method of the present invention is used to realize the electrical interconnection of the lead legs of the through-hole device to the outside, on the one hand, for a single lead leg, after connection, whether the connection is reliable can be quantitatively evaluated by a pull-out force test for its firmness; on the other hand, for the through-hole devices of the same batch, it is not necessary to perform a pull-out force test on each lead leg that has been connected to the pin terminal, saving test time and test cost.

[0042] (3) The closed pit-pressure terminal in the present invention is preferably a J599 type closed terminal 22D#, and the pin terminal and the hole terminal are preferably made of a copper material as the inner base and a gold-plated outer covering layer. It adopts a gold plating process, has good contact resistance, and excellent electrical performance.

[0043] (4) In the present invention, for the external electrical interconnection of the lead legs of a plug-in type device with a preset pull-off force value F0 in the range of 34N to 40N, a preferred model and gear position of the crimping pliers, a model of the positioner, and a preferred preset pull-off force difference threshold value △F0 are provided for quickly finding out the cause of the failure of the pull-off force test and reducing the number of attempts required to determine the appropriate gear position of the crimping pliers. The invention is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic structural diagram of externally electrically interconnecting the leads on a through-hole packaged lamp in step 8 of an embodiment of a through-hole device lead connection method of the present invention.

[0045] The descriptions of the numbers in the figure are as follows:

[0046] 1- plug-in package lamp, 2- lead leg, 3- extrusion point, 4- pin terminal, 5- mating point, 6- hole terminal, 7- heat shrink protective sleeve, 8- wire, 9- observation port of pin terminal, 10- observation port of hole terminal. DETAILED DESCRIPTION

[0047] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] See also Figure 1 The present invention provides a method for connecting the lead legs of a plug-in device, which is used for connecting the lead legs of a plug-in device with a length greater than or equal to 10 mm. In this embodiment, the plug-in device is a plug-in packaged lamp 1, whose lead legs are partially encapsulated in the glass body and partially outside the glass body. The lead legs 2 outside the glass body are responsible for electrical interconnection with the outside world. The material of the lead legs 2 is iron, cobalt, and nickel. When the plug-in device lead leg connection method of the present invention is used to electrically interconnect with the outside world, it is required that the length of the lead legs 2 on the plug-in packaged lamp 1 cannot be less than 10 mm, because of the length requirements and stress release requirements of the closed point extrusion process; in this embodiment, the length of the lead legs 2 on the plug-in packaged lamp 1 is 20 mm, which ensures the requirements of at least 5 mm in length of the closed point extrusion process and more than 5 mm in stress release. In this way, after the lead legs 2 on the plug-in packaged lamp 1 are connected, stress damage will not be caused to the glass package body. In this embodiment, the minimum pull-off force value that needs to be met after the lead legs 2 are electrically connected to the pin terminal 4 is 34N.

[0049] When the lead leg connection method of the through-hole device of the present invention is used to electrically interconnect the lead leg 2 on the through-hole package lamp 1, the method includes the following steps:

[0050] Step 1: Adjust the gear of the crimping pliers to the preset gear; in this embodiment, the model of the crimping pliers is preferably M22520 / 2-01, the model of the positioner installed on the crimping pliers is preferably K42, and the initial value of the preset gear of the crimping pliers is 2, that is, when making external electrical interconnections of the first lead leg on the same batch of direct-plug packaged lamps 1, the gear of the crimping pliers is initially adjusted to 2.

[0051] Step 2: Use the crimping pliers with the gear adjusted in step 1 to connect the lead leg 2 of the plug-in device to the closed point extrusion end of the needle terminal 4 in the closed pit pressure terminal through a closed point extrusion method; in order to ensure reliable connection, convenient procurement and low cost, in this embodiment, the closed pit pressure terminal preferably uses the J599 type closed terminal 22D#, which has a cylindrical shape with a diameter of 0.8mm and a length of 8mm. In order to have good contact resistance and excellent electrical performance, the needle terminal 4 and the hole terminal 6 in the above-mentioned J599 type closed terminal 22D# are made of copper material as the internal matrix and gold-plated material as the outer wrapping layer. In this embodiment, in order to make the connection more firm under the same gear condition of the crimping pliers, the specific operation method of the above-mentioned closed point extrusion method is as follows:

[0052] Step A: Place the pin terminal 4 in the closed pit crimping terminal into the jaws of the crimping pliers, and make the pin terminal 4 press against the bottom end of the positioner on the crimping pliers, so that the pin terminal 4 and the positioner are well matched;

[0053] Step B: insert the lead leg 2 of the through-hole device into the pressure hole of the pin terminal 4 that cooperates well with the positioner in step A until it touches the bottom, and ensure that the lead leg 2 of the through-hole device can be seen from the observation port 9 of the pin terminal;

[0054] Step C: operate the crimping pliers to perform a closed point squeezing operation to form squeezing point 3 and complete the operation.

[0055] Step 3: Perform a pull-off force test on the lead leg 2 and the pin terminal 4 connected as one in step 2; in this embodiment, a pull-off force tester is used to perform the pull-off force test;

[0056] If the pull-off force test value F reaches the preset pull-off force value F0, and the connection between the lead leg 2 and the pin terminal 4 is not broken, it is determined that the test is qualified, and step 7 is executed; the preset pull-off force value F0 is determined according to the requirements in the actual use environment;

[0057] If the pull-off force test value F does not reach the preset pull-off force value F0, the connection between the lead leg 2 and the pin terminal 4 is broken, the test is judged to be unqualified, and the pull-off force test value F1 at the time of the break is recorded, and then the difference △F obtained by F0-F1 is compared with the preset pull-off force difference threshold △F0: if △F<△F0, execute step 4; if △F≥△F0, re-take the same batch of direct-insert devices and the pin terminal 4 in the closed pit crimping terminal to which the lead leg 2 has not been connected, and then return to step 1 and increase the preset gear of the crimping pliers;

[0058] The preset pull-off force difference threshold △F0 is determined based on experience, and is usually (20% to 25%) F0. When the preset pull-off force value F0 is within the range of 34N to 40N, the initial value of the preset gear in step 1 is preferably 2 gears, and the preset pull-off force difference threshold △F0 is preferably 8N, which is 8N in this embodiment; in this way, the reason for the failure of the pull-off force test can be found out as soon as possible, reducing the number of attempts required to determine the appropriate gear of the crimping pliers.

[0059] Step 4: Re-take the same batch of direct-insert type devices and the pin terminal 4 in the closed pit pressure terminal whose lead leg 2 has not been connected, clean the lead leg 2 of the direct-insert type device and the pin terminal 4 first, and then use the crimping pliers adjusted to the gear position in step 1 to connect the lead leg 2 of the direct-insert type device with the closed point extrusion end of the pin terminal 4 by closed point extrusion;

[0060] Step 5: Perform a pull-off force test on the lead leg 2 and the pin terminal 4 connected as one;

[0061] If the pull-off force test value F reaches the preset pull-off force value F0, and the connection between the lead leg 2 and the pin terminal 4 is not broken, it is determined that the test is qualified, and step 7 is executed;

[0062] If the pull-off force test value F does not reach the preset pull-off force value F0, the connection between the lead leg 2 and the pin terminal 4 is broken, and the test is judged to be unqualified, and step 6 is executed;

[0063] Step 6: Re-take the same batch of direct-insert type devices and the pin terminal 4 in the closed pit crimping terminal whose lead leg 2 has not been connected, and increase the preset gear of the crimping pliers, connect the lead leg 2 of the direct-insert type device with the closed point extrusion end of the pin terminal 4 by closed point extrusion, and then return to step 5;

[0064] Step 7: Plug and connect the plug-in connection end of the pin terminal 4 connected to the lead leg 2 with the plug-in connection end of the hole terminal 6 in the closed pit pressure terminal connected to the wire 8 to form a matching point 5; in this embodiment, when the above-mentioned wire 8 is connected to the hole terminal 6 in the closed pit pressure terminal, an operation method similar to the closed point extrusion method when connecting the lead leg 2 of the direct plug-in type device with the pin terminal 4 in the closed pit pressure terminal is also adopted, that is, the hole terminal 6 is used to replace the pin terminal 4, the wire 8 replaces the lead leg 2 of the direct plug-in type device, and the observation port 10 of the hole terminal replaces the observation port 9 of the pin terminal, and then the same method is used.

[0065] Step 8: After the pin terminal 4 and the hole terminal 6 are connected in step 7, a heat shrink protective sleeve 7 is put on the whole outside, and a hot air blower is used to shrink the heat shrink protective sleeve 7 so that it is heat-shrunk and adhered to the outer surface of the pin terminal 4 and the hole terminal 6. After wrapping the whole, let it stand for 10 minutes to 20 minutes to complete the connection between the lead leg 2 of the direct plug-in device and the wire 8. In order to ensure that the heat shrink protective sleeve 7 is firmly adhered to the outer surface of the pin terminal 4 and the hole terminal 6 after heat shrinkage, and can wrap the pin terminal 4 and the hole terminal 6 as a whole, protect the entire structure from external force and meet the requirements of moisture resistance, salt spray resistance and mildew resistance, the above-mentioned heat shrink protective sleeve 7 adopts a transparent heat shrink protective sleeve, and its diameter is preferably 2mm~3mm. After the heat shrink protective sleeve 7 is put on the overall outside of the pin terminal 4 and the hole terminal 6 after the plug-in connection, its two ends are preferably 2mm~4mm longer than the two ends of the overall outside of the pin terminal 4 and the hole terminal 6 after the plug-in connection; when the heat shrink protective sleeve 7 is blown and shrunk by a hot air gun, its heat shrinkage temperature is preferably 120℃±5℃, and the heat shrinkage time is preferably 10S~15S. In this embodiment, in order to shrink quickly after being heated, the transparent heat shrink protective sleeve is made of polyolefin, the diameter of the heat shrink protective sleeve 7 is 3 mm, and the two ends are 2 mm longer than the outer ends of the pin terminal 4 and the hole terminal 6 after the plug-in connection. The heat shrinking temperature is 120°C, the heat shrinking time is 10S, and it is left to stand for 20 minutes after the heat shrinking is completed.

[0066] In order to make the extrusion force during connection appropriate and save test time and test cost when the lead legs of through-hole type devices of the same batch are electrically interconnected to the outside, the through-hole type device lead leg connection method of the present invention preferably also includes step 9, connecting the lead legs 2 of other through-hole type devices of the same batch whose lead legs 2 have not been connected to the outside with the corresponding wires 8, specifically:

[0067] Step 9.1: Connect the lead 2 of other through-hole devices of the same batch that have not been connected yet to the closed point extrusion end of the pin terminal 4 of the corresponding closed pit crimping terminal by using the crimping pliers whose gears have been adjusted for the last time;

[0068] Step 9.2: Use the method of step 7 to step 8 to complete the connection between the lead pins 2 of other through-hole devices of the same batch whose lead pins 2 have not been connected and the corresponding wires 8.

[0069] The wire 8 is used for electrical interconnection with the outside world. From the above connection process, it can be seen that, by using the direct-plug device lead leg connection method of the present invention, the first lead leg to be electrically interconnected to the outside in the direct-plug type devices of the same batch will be subjected to a pull-off force test after the connection with the pin terminal is completed, and the test is used to determine whether it is necessary to adjust the gear position of the crimping pliers; after the gear position of the crimping pliers is adjusted appropriately, when the lead legs of other direct-plug type devices of the same batch are electrically interconnected to the outside, there is no need to perform a pull-off force test; therefore, by using the direct-plug type device lead leg connection method of the present invention, when the lead legs of the direct-plug type device are electrically interconnected to the outside, on the one hand, for a single lead leg, after connection, whether the connection is reliable can be quantitatively evaluated by a pull-off force test for its firmness; on the other hand, for the direct-plug type devices of the same batch, there is no need to perform a pull-off force test on each lead leg connected to the pin terminal, which saves test time and test costs.

[0070] The plug-in device lead connection method of the present invention is applied in the design of a certain type of high-voltage power supply. After electrical performance testing, temperature cycling, and random vibration tests, the extrusion point has a good appearance and the electrical connection is reliable, indicating that the method can meet the requirements of high-voltage characteristics and connection characteristics.

[0071] In summary, the direct-insertion device lead connection method of the present invention not only has reliable connection quality, small size, and excellent electrical performance, but also has good interchangeability, high manufacturing efficiency, and low cost, and the connection firmness can be quantitatively evaluated.

Claims

1. A method for connecting lead legs of a through-hole device, used for connecting lead legs of a through-hole device with a length greater than or equal to 10 mm, characterized in that: The following steps are involved: Step 1: Adjust the gear of the crimping pliers to the preset gear; Step 2: Use the crimping pliers adjusted to the correct position in step 1 to connect the lead leg (2) of the plug-in device to the closed point extrusion end of the pin terminal (4) in the closed pit crimping terminal by means of closed point extrusion; Step 3: Perform a pull-off force test on the lead leg (2) and the pin terminal (4) connected as one in step 2; If the pull-off force test value F reaches the preset pull-off force value F0, and the connection between the lead leg (2) and the pin terminal (4) is not broken, it is judged that the test is qualified and step 7 is executed; If the pull-off force test value F does not reach the preset pull-off force value F0, the connection between the lead leg (2) and the pin terminal (4) is broken, and the test is judged to be unqualified, and the pull-off force test value F1 at the time of the break is recorded, and then the difference △F obtained by F0-F1 is compared with the preset pull-off force difference threshold △F0: if △F<△F0, then execute step 4; if △F≥△F0, then re-take the same batch of direct plug-in type devices and the pin terminal (4) in the closed pit crimping terminal that the lead leg (2) has not yet been connected, and then return to step 1 and increase the preset gear of the crimping pliers; Step 4: Re-take the same batch of direct-insert type devices and the pin terminal (4) in the closed pit pressure terminal whose lead leg (2) has not been connected, clean the lead leg (2) of the direct-insert type device and the pin terminal (4) first, and then use the crimping pliers adjusted to the gear position in step 1 to connect the lead leg (2) of the direct-insert type device with the closed point pressing end of the pin terminal (4) by closed point pressing; Step 5: Perform a pull-off force test on the lead leg (2) and the pin terminal (4) connected as one; If the pull-off force test value F reaches the preset pull-off force value F0, and the connection between the lead leg (2) and the pin terminal (4) is not broken, it is judged that the test is qualified and step 7 is executed; If the pull-off force test value F does not reach the preset pull-off force value F0, the connection between the lead leg (2) and the pin terminal (4) is broken, and the test is judged to be unqualified, and step 6 is executed; Step 6: Re-take the same batch of direct-insert type devices and the pin terminal (4) in the closed pit crimping terminal whose lead leg (2) has not been connected, and increase the preset gear of the crimping pliers, connect the lead leg (2) of the direct-insert type device with the closed point extrusion end of the pin terminal (4) by closed point extrusion, and then return to step 5; Step 7: plug and connect the plug-in connection end of the pin terminal (4) connected to the lead leg (2) with the plug-in connection end of the hole terminal (6) of the closed-type pit-pressed terminal connected to the wire (8) to form a matching point (5); Step 8: After the pin terminal (4) and the hole terminal (6) are connected in step 7, a heat shrink protective sleeve (7) is put on the whole outside, and a hot air blower is used to shrink the heat shrink protective sleeve (7) so that it is heat-shrunk and adhered to the outer surface of the pin terminal (4) and the hole terminal (6). After wrapping the whole, let it stand for 10 minutes to 20 minutes, and the connection between the lead leg (2) of the direct plug-in type device and the wire (8) is completed.

2. The method for connecting lead pins of a through hole device according to claim 1, characterized in that: The step also includes step 9, connecting the lead legs (2) of other through-hole devices of the same batch that have not yet been connected with the lead legs (2) with the corresponding wires (8), specifically: Step 9.1: Connect the lead legs (2) of other through-hole devices of the same batch that have not been connected yet to the closed point extrusion end of the pin terminal (4) of the corresponding closed pit crimping terminal by means of closed point extrusion using the crimping pliers whose gears have been adjusted for the last time; Step 9.2: Use the method of step 7 to step 8 to complete the connection between the lead pins (2) of other through-hole type devices of the same batch whose lead pins (2) have not been connected and the corresponding wires (8).

3. The method for connecting lead pins of a through hole device according to claim 1, characterized in that: The specific operation method of the closed point extrusion method is: Step A: placing the pin terminal (4) in the closed pit crimping terminal into the jaws of the crimping pliers, and making the pin terminal (4) press against the bottom end of the positioner on the crimping pliers, so that the pin terminal (4) and the positioner are well matched; Step B: inserting the lead leg (2) of the through-hole device into the pressure hole of the pin terminal (4) that matches the positioner well in step A until it touches the bottom, ensuring that the lead leg (2) of the through-hole device can be seen from the observation port (9) of the pin terminal; Step C: operate the crimping pliers to perform a closed point squeezing operation to form a squeezing point (3) and complete the operation.

4. The method for connecting lead pins of a through hole device according to claim 1, characterized in that: The preset pull-off force difference threshold ΔF0 is (20% to 25%) F0.

5. The method for connecting lead pins of a through hole device according to claim 1, characterized in that: The closed pit pressure terminal uses J599 type closed terminal 22D#.

6. The method for connecting lead pins of a through hole device according to claim 5, characterized in that: The J599 type closed terminal 22D# middle needle terminal (4) and hole terminal (6) are both made of copper material as the inner base and gold-plated material as the outer covering layer.

7. The method for connecting lead legs of a through hole device according to claim 5, characterized in that: The model of the crimping pliers is M22520 / 2-01, and the model of the positioner installed on the crimping pliers is K42.

8. The method for connecting lead legs of a through hole device according to claim 7, characterized in that: When the pull-off force test is performed, a pull-off force tester is used to perform the pull-off force test; When the preset pull-off force value F0 is within the range of 34N to 40N, the initial value of the preset gear in step 1 is gear 2, and the preset pull-off force difference threshold ΔF0 is 8N.

9. The method for connecting lead pins of a through hole device according to claim 5, characterized in that: In step 8, the heat shrinkable protective sleeve (7) is a transparent heat shrinkable protective sleeve with a diameter of 2 mm to 3 mm; After the heat shrink protective sleeve (7) is sleeved on the entire exterior of the pin terminal (4) and the socket terminal (6) after the plug-in connection, the two ends of the heat shrink protective sleeve (7) are respectively extended by 2 mm to 4 mm from the two ends of the entire exterior of the pin terminal (4) and the socket terminal (6) after the plug-in connection; When the heat shrink protective sleeve (7) is shrunk by using a hot air blow gun, the heat shrinking temperature is 120°C±5°C and the heat shrinking time is 10S to 15S.

10. The method for connecting pins of a through hole device according to claim 9, characterized in that: The material of the transparent heat shrinkable protective sleeve is polyolefin.

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