JP4016266B2 - Proximity sensor sealing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing method for a proximity sensor, and more particularly to a sealing method for preventing oil water or the like from entering a shell case that accommodates circuit components and the like to cause deterioration of characteristics.
[0002]
[Prior art]
An inductive proximity sensor that senses the approach of a metal body is often installed in a poor environment that is exposed to oil and water. For this reason, the gap between the outer shell case of this type of proximity sensor and the built-in circuit components is filled with resin for sealing from oil or the like. In order to obtain perfect sealing performance, the sealing resin must be filled in the outer shell case without any gaps. However, since there are many fine voids with complicated shapes in the outer shell case when the assembly process is completed, it is impossible to completely seal circuit components etc. by filling the outer shell case with fluid resin without gaps It's not easy.
[0003]
As a conventional sealing method, a maze-like air vent passage is formed between the coil case and the outer shell case, while the sensor housing is placed in a reduced pressure environment, so that the air in the outer shell case is removed from the tip of the outer shell case. There is known a technique in which a fluid resin is injected into the outer shell case while sucking it from the outside (see Patent Document 1).
[0004]
As another sealing method, a funnel-type resin injection jig is integrally formed on the cable presser that is a fastener for the electric cord drawn out from the rear end of the outer shell case, and the resin flows into the jig. There is known a technique in which a resin is temporarily stored and then resin injection into the outer shell case is performed with vacuum suction, and the resin injection jig is removed after the injection is completed (see Patent Document 2).
[0005]
Furthermore, as another sealing method, an end plug member for closing the rear end portion of the outer shell case is provided with an injection duct for injecting resin and a discharge duct for discharging resin and air, and the proximity sensor is subjected to centrifugal force. While fixing to the application rotor and applying centrifugal force toward the tip of the outer shell case, let the flow resin injection from the injection duct, exhaust from the exhaust duct and resin overflow, and apply centrifugal force until the flow resin is cured One that keeps applying is known (see Patent Document 3).
[0006]
[Patent Document 1]
Japanese Patent No. 3279187
[Patent Document 2]
Japanese Patent Laid-Open No. 06-060763
[Patent Document 3]
JP 05-157500 A
[0007]
[Problems to be solved by the invention]
However, since the sealing method according to Patent Documents 1 to 3 described above employs a configuration in which a dedicated air discharge path is provided separately from the resin injection path, the structure becomes complicated and the cost increases. The problem to be pointed out is pointed out. Moreover, although the sealing method according to Patent Documents 1 and 2 is to fill the fluid resin while sucking air in the outer shell case, the positional relationship between the resin injection portion and the exhaust portion is not limited to this. Depending on the overall shape, air may remain, and it takes trial and error to properly set process conditions such as air pressure and resin injection speed, and it is not easy to eliminate air residue. It was. Furthermore, the sealing method according to Patent Document 3 has a complicated structure for supplying resin during application of centrifugal force.
[0008]
The present invention has been made by paying attention to the above-mentioned problems, and the object of the present invention is to flow closely to every corner in the outer shell case without providing a dedicated air discharge path for air venting. An object of the present invention is to provide a proximity sensor sealing method that can inject a resin and securely seal a built-in circuit component or the like.
[0009]
Another object of the present invention is to simplify the centrifugal force application process and the apparatus used therefor when the centrifugal force is applied to discharge air.
[0010]
Other objects and operational effects of the present invention will be easily understood by those skilled in the art by referring to the description of the following specification.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the proximity sensor sealing method according to the present invention provides a front end of the outer shell case with respect to a proximity sensor intermediate product in which the detection coil assembly and the component mounting circuit board are incorporated in the outer shell case. The air filling the gap in the outer shell case by using the mass difference between the fluid resin and air by pouring the fluid resin from the opening provided in the rear part of the outer shell case while applying centrifugal force in the direction The exchange with the poured fluid resin is forcibly performed, and at the same time, the air retreated from the gap by the exchange is naturally discharged from the opening itself used to pour the fluid resin.
[0012]
According to such a configuration, the fluid resin injected into the outer shell case is forcibly transferred toward the tip in the outer shell case by centrifugal force. It is possible to securely seal the built-in circuit components and the like by injecting tightly. On the other hand, air that has been retreated from the gap due to the exchange of the air filling the gap in the outer shell case with the poured fluid resin is naturally discharged from the opening itself used to pour the fluid resin. Therefore, it is not necessary to provide a dedicated air discharge path, and the structure of related parts is simplified correspondingly, thereby contributing to cost reduction of the product.
[0013]
Usually, the application of centrifugal force is performed by a centrifugal force application device that accompanies a rotational motion, and therefore there is a risk that an electric coat is attached at the resin injection stage. From this point, the method of the present invention can be applied without difficulty if it is a proximity sensor of an electric cord attaching / detaching type. However, even if the proximity sensor is of the electric cord fixing type, there is no problem in application if a process for connecting the electric cord is adopted after the resin injection step is completed.
[0014]
If the present invention is applied to a proximity sensor of an electrical cord attachment / detachment system that is detachable through a receptacle fixed to the outer shell case side and a plug fixed to the electrical cord side, as one embodiment, It becomes as follows.
[0015]
That is, in a preferred embodiment, the intermediate product of the proximity sensor includes a cylindrical outer shell case, a detection coil assembly that closes the front end opening of the outer shell case, and a terminal that closes the rear end opening of the outer shell case. A pin built-in receptacle, and a component mounting circuit board disposed in the outer shell case and disposed between the detection coil assembly and the terminal pin built-in receptacle, and the terminal pin built-in receptacle includes a resin spout and An opening that is also used as an air escape port is provided.
[0016]
On the premise of the proximity sensor intermediate product having such a structure, processing is performed according to the following first to fourth steps. That is, in the first step, the resin reservoir hopper is coupled to a rear end portion of the proximity sensor intermediate product with a predetermined jig so that the opening on the outflow side of the resin reservoir hopper and the terminal pin are incorporated. The receptacle also serves as an inlet / exhaust opening. In the second step, the fluid resin is discharged into the resin reservoir hopper by an amount that slightly exceeds the capacity of the gap in the outer shell case in a state where the proximity sensor intermediate product is almost upright with the tip portion down. . In the subsequent third step, a combined body of the proximity sensor intermediate product and the resin reservoir hopper is attached to the centrifugal force application device, and the centrifugal force is applied toward the distal end of the proximity sensor intermediate product. In the following fourth step, the combined body of the proximity sensor intermediate product and the resin reservoir hopper is removed from the centrifugal force application device, and the resin injected and filled in the outer shell case is cured.
[0017]
At this time, as the receptacle having a built-in terminal pin, a cylindrical receptacle case press-fitted into the rear end portion of the outer shell case, and a step inserted into the receptacle case from the front end side toward the rear end side and on the inner periphery of the receptacle case A terminal pin assembly that abuts against the portion and is prevented from moving forward, and the terminal pin assembly includes a plurality of parallel pins serving as receptacle pins, a pin holder that bundles and holds the plurality of pins, and a pin holder A resin injection pipe portion to be cut and connected to the central through-hole is integrally formed. Further, in the first step, the tip opening of the resin injection pipe and the resin reservoir hopper A resin reservoir hopper is coupled to the rear end of the proximity sensor intermediate product with a predetermined jig so that the opening on the outflow side is joined. The terminal pin assembly is integrated with the centrifugal force application device via the resin injection pipe when the combined proximity sensor intermediate product and the resin reservoir hopper are attached to the centrifugal force application device and the centrifugal force is applied. If the receptacle case integrated with the outer shell case is slidable with respect to the terminal pin assembly, the pin holder of the terminal pin assembly and the receptacle case when centrifugal force is applied. Since the centrifugal force acts in the direction in which the resin leakage gap formed between the peripheral stepped portions is narrowed, the flowing resin can be prevented from leaking while the centrifugal force is applied by the centrifugal force application device.
[0018]
Further, the proximity sensor sealing method of the present invention is the first method provided at the rear part of the outer shell case with respect to the proximity sensor intermediate product in which the detection coil assembly and the component-mounted circuit board are incorporated in the outer shell case. The fluid resin is filled in the outer shell case by filling the fluid resin in the outer shell case by discharging air repelled from the second opening provided at the rear of the outer shell case while pouring the fluid resin while pressurizing from the opening. By applying a centrifugal force toward the tip of the outer shell case with respect to the proximity sensor intermediate product, air and fluid resin that fills the slits in the outer shell case using the mass difference between the fluid resin and air At the same time, the air retreated from the slit by the position exchange is naturally discharged from the first and second openings provided in the rear part of the outer shell case.
[0019]
According to such a configuration, air that is retreated from the second opening provided at the rear part of the outer shell case is released while the fluid resin is poured while being pressurized from the first opening provided at the rear part of the outer shell case. Thus, the operation of filling the fluid resin into the outer shell case for the time being can be performed quickly using a pressure injection device. On the other hand, the step of allowing the flowing resin to enter every corner of the outer shell case can be reliably performed using a centrifugal force application device. At this time, the air retreated from the gap by the exchange of the air filling the gap in the outer shell case and the poured fluid resin is the opening used for pouring the fluid resin and the opening used for discharging the resin. Since the air is naturally discharged from both sides, the air can be discharged more reliably by a simple process than when the air in the outer shell case is sucked. Further, in the step of applying the centrifugal force, a structure for injecting a fluid resin such as a large hopper is not required.
[0020]
Usually, the application of centrifugal force is performed by a centrifugal force application device that accompanies a rotational motion, and therefore there is a risk that an electric coat is attached at the resin injection stage. From this point, the method of the present invention can be applied without difficulty if it is a proximity sensor of an electric cord attaching / detaching type. However, even if the proximity sensor is of the electric cord fixing type, there is no problem in application if a process for connecting the electric cord is adopted after the resin injection step is completed.
[0021]
If the present invention is applied to a cord-fixed proximity sensor in which an electric cord is directly drawn out from an end plug that closes the rear end opening of the outer shell case, an embodiment is as follows.
[0022]
That is, in a preferred embodiment, the intermediate product of the proximity sensor projects the connection pad portion provided at the rear end portion of the component-mounted circuit board from the end plug that closes the rear end opening of the outer shell case. A cord fixing system in which the conductor of the core wire drawn from the cord is connected to the connection pad, and then the cord protector that encloses the space between the rear end face of the end plug and the outer sheath tip of the electric cord is resin-molded It corresponds to the proximity sensor.
[0023]
Specifically, the intermediate product of the proximity sensor includes a cylindrical outer shell case, a detection coil assembly that closes the front end opening of the outer shell case, an end plug that closes the rear end opening of the outer shell case, A component mounting circuit board in which the connection pad portion provided in the rear end portion of the outer shell case passes through the end plug and protrudes to the outside, and the end plug includes a resin spout and air The first and second openings respectively corresponding to the relief openings and the first and second resin reservoir hoppers connected to the openings are integrally molded.
[0024]
On the premise of the proximity sensor intermediate product having such a structure, processing is performed according to the following first to fourth steps. That is, in the first step, in the state where the proximity sensor intermediate product is almost upright with the tip portion down, the fluid resin is removed from the first resin reservoir hopper until the fluid resin overflows from the second resin reservoir hopper. Pressurize into the outer shell case. In the subsequent second step, the proximity sensor intermediate product in which the inside of the outer shell case is filled with the fluid resin and the fluid resin is accumulated in the first and second resin reservoir hoppers is attached to the centrifugal force application device, Centrifugal force is applied toward the tip of the proximity sensor intermediate product. In the subsequent third step, the proximity sensor intermediate product is removed from the centrifugal force application device, and the resin injected and filled in the outer shell case is cured. In the subsequent fourth step, the first and second resin reservoir hoppers are cut off after the resin injected and filled in the outer shell case is cured.
[0025]
According to such a configuration, in the state in which the proximity sensor intermediate product is almost upright with the tip portion down, the fluid resin is discharged from the first resin reservoir hopper until the fluid resin overflows from the second resin reservoir hopper. Is injected into the outer shell case under pressure so that the fluid resin can be quickly injected into the outer shell case. After that, when the centrifugal force is applied, the fluid resin spreads to every corner in the outer shell case. At the same time, the resin stored in the first and second resin reservoir hoppers is returned to the outer shell case as the fluid resin is cured and contracted in the outer shell case. There is no gap caused by the shortage. Finally, since these resin reservoir hoppers are cut off, the subsequent assembly process is not hindered.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
In the following, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. The embodiment shown in the drawings is, of course, merely an example of the present invention, and the scope of the present invention is defined only by the description of the scope of claims.
[0027]
As is well known, this type of proximity sensor includes an electric cord attaching / detaching type shown in FIG. 21 (a) and an electric cord fixing type shown in FIG. 21 (b).
[0028]
In FIG. 21A, 100 is a proximity sensor, 101 and 102 are tightening nuts, 103 is a toothed washer, 200 is an electric cord, 201 is a cord protector, 202 is a plug holder, 203 is a plug, and 204 is a cap nut. . In addition, 1 is a cylindrical outer shell case constituting the housing of the proximity sensor 100, and 20 is a coil case protruding from the tip of the outer shell case 1. In the proximity sensor of the electric cord attachment / detachment type, it can be freely connected and separated via a receptacle (not shown) fixed to the outer shell case 1 side and a plug 203 fixed to the electric cord 200 side. The connection state between the plug and the receptacle is maintained by screwing the cap nut 204 into the outer peripheral thread portion of the outer shell case 1.
[0029]
In FIG. 21B, 300 is a proximity sensor, 301 and 302 are tightening nuts, 303 is a toothed washer, 400 is an electric cord, and 401 is a cord protector. Reference numeral 1 denotes an outer shell case of the proximity sensor 300. In the proximity sensor of the electric cord fixing type, the electric cord 400 is kept pulled out from an end plug (not shown) that closes the rear end portion of the outer shell case 1, and the electric cord 400 is attached and detached. I can't.
[0030]
The sealing method of the present invention can be applied to both the above-described proximity sensor of the electric cord attaching / detaching type and the proximity sensor of the electric cord fixing type. Therefore, first, an application example in the proximity sensor of the electric cord attaching / detaching method will be described in detail with reference to FIGS.
[0031]
The entire configuration of the proximity sensor to which the sealing method of the present invention is applied is shown in an exploded perspective view of FIG. 1 and sectional views of FIGS. 2A is a longitudinal sectional view in the assembled state of the proximity sensor 100 shown in FIG. 1, FIG. 2B is a rear view of the proximity sensor 100 (shape viewed from the rear of the sensor), and FIG. 2B is a cross-sectional view of the proximity sensor 100 shown in FIG. 2B, and FIG. 4 is a cross-sectional view of the proximity sensor 100 shown in FIG.
[0032]
As shown in FIG. 1, this proximity sensor 100 includes a detection end module 2, a connection member 3, an output circuit assembly 4, and terminal pins constituting a connector in a metal cylindrical outer shell case 1. The assembly 5 and the receptacle case 6 are accommodated.
[0033]
As shown in FIGS. 2 to 4, the detection end module 2 is electrically connected to a detection coil assembly 22 including a coil (coil spool) 22 a and a ferrite core 22 b, and the detection coil assembly 22. The detection circuit assembly 21 is accommodated in a bottomed cylindrical coil case 20 made of synthetic resin.
[0034]
Further, a pair of metal terminal pieces 23a and 23b protrude from the coil spool 22a of the detection coil assembly 22 (see FIG. 4). The detection circuit assembly 21 includes an oscillation circuit having a coil 22a as a resonance circuit element, and includes a detection circuit mounted with a detection circuit that generates an object detection signal in a certain form corresponding to the oscillation state of the oscillation circuit mounted on a rectangular substrate. The metal terminal pieces 23a and 23b of the detection coil assembly 22 are respectively soldered to the terminal portions 21a and 21b shown in FIG. 4 so as to be supported and electrically connected to the detection circuit assembly. It has been subjected. The detection end module 2 is configured as described above, and is press-fitted into the front end portion of the outer shell case 1 via the coil case 20.
[0035]
Note that reference numeral 24 in the figure denotes a mask member that is press-fitted and fitted to the front end peripheral edge of the coil case 20. In this example, the presence or absence of the outer shell case 1 is achieved by attaching the mask member 20. Therefore, the detection end module 2 that does not significantly affect the detection characteristics (complete characteristics) is realized. Note that the completion of the characteristics is not directly related to the main part of the present invention, and thus detailed description thereof is omitted here.
[0036]
Next, the connecting member 3 is made of a polyimide base material on which flexible wiring patterns of the number necessary for electrically connecting the detection circuit assembly 21 and the output circuit assembly 4 are formed. It is a substrate. In this example, the connecting member 3 is thermocompression bonded to the terminal pad portions (not shown) provided in the detection circuit assembly 21 and the output circuit assembly 4 by using solder or a conductive adhesive, and bridges both. Electrical connection is made so that power supply / reception between the detection circuit assembly 21 and the output circuit assembly 4 and input / output of an object detection signal are possible.
[0037]
Next, the output circuit assembly 4 is an output circuit mounting board in which an output circuit for driving an output element based on an object detection signal input from the detection circuit assembly 21 via the connection member 3 is mounted on a rectangular rigid board. It is. More specifically, the output circuit assembly incorporates a logic circuit, an output control circuit, and an output transistor, and after the input object detection signal is logically processed through the logic circuit, the output is performed. By operating the output transistor via the control circuit, a signal of a desired format based on the object detection signal is output to the outside from the terminal pin assembly 5 described in detail later.
[0038]
In FIG. 1 or FIG. 4, reference numeral 41 denotes a terminal pad portion to which the terminal pins of the terminal pin assembly 5 are soldered. Although not clearly shown in the figure, the terminal pin assembly 5 In correspondence with the number of terminal pins (four in this example), two (two in total) are provided on the front and back.
[0039]
Next, the structure of the receptacle used for attachment / detachment with the plug on the electric cord side will be described step by step. The receptacle applied to the proximity sensor of the present invention includes a terminal pin assembly 5 and a cylindrical receptacle case 6 as shown in FIGS.
[0040]
Details of the terminal pin assembly are shown in an overall perspective view of FIG. 5, a plan view of FIG. 6, and a cross-sectional view of FIG. 5 to 7 show a terminal pin assembly 5 with a pipe before the pipe cutting described later. 6A shows the shape of the front end face of the terminal pin assembly 5 with a pipe (shape of the surface directed to the output circuit assembly 4), and FIG. 6B shows the terminal pin assembly 5 with a pipe. FIG. 7 shows a DD cross-sectional view of the terminal pin assembly 5 with a pipe shown in FIG. 5, and the shape of the rear end face (the shape of the face directed to the receptacle case 6).
[0041]
As shown in FIG. 1, the terminal pin assembly 5 is formed by inserting four terminal pins 51 having the same shape through a pin holder portion 50 that is a disc-shaped base. The terminal pin assembly 5 shown in FIG. 5 to FIG. 7 is in a state before cutting the pipe, which will be described later, and includes four pins 51 serving as terminal pins with a built-in receptacle, and bundling these four pins 51 together. It has the pin holder part 50 to hold | maintain, and the resin injection | pouring pipe part 52 of the cutting plan connected with the center through-hole 500 of the pin holder part 50. In addition, the pin holder part 50 and the pipe part 52 are manufactured as a resin integral molded product.
[0042]
As shown in FIG. 6A, the front end surface of the pin holder portion 50 is provided with two pairs of fitting grooves 501-501 and 502-502 arranged in a line in the vertical direction and the horizontal direction, respectively. At the time of sensor assembly, the side edge portion (see FIG. 2) of the substrate 42 of the output circuit assembly 4 is fitted into any one of the pair of fitting grooves (501-501 or 502-502), whereby the pin holder portion 50 ( The terminal pin assembly 5) is approximately positioned with respect to the output circuit assembly 4. Thereafter, as will be described later, the terminal pin assembly 5 is fixed to the output circuit assembly 4 by soldering the terminal pin 51 to the output circuit assembly 4.
[0043]
As shown in FIG. 6B, a set of notches 503-503 serving as a joint portion with the receptacle case 6, which will be described in detail later, is provided on the rear end surface of the pin holder portion 50.
[0044]
As shown in FIG. 7, the resin injection pipe portion 52 includes a through hole (hollow portion) 520 that is connected to the through hole 500 of the pin holder portion 50 and forms a resin inflow path at the time of resin filling described later. A pair of protrusions 52a and 52b are provided on the outer peripheral surface for locking to a jig described later. As shown in an enlarged view in FIG. 7, the connecting portion 53 between the pin holder portion 50 and the pipe portion 52 is thin, and the pin 52 is pinched by pinching the protrusions 52a and 52b with the pin holder portion 50 fixed. If the pipe 52 is rotated (twisted), the pipe 52 can be easily separated from the pin holder portion 50.
[0045]
The four terminal pins 51 electrically connect an external plug (not shown) connected to the electric cord side and the output circuit assembly 5, and are aligned and held in parallel with each other by the pin holder unit 50. In this example, the connection end portion 51a with the detection circuit assembly 5 is formed slightly thinner than the connection end portion 51b with the external plug, and a step portion (see FIG. 4) is provided in the middle, so that the pin holder portion 50 has A terminal pin is prevented from coming off when the terminal pin 51 is inserted and the terminal pin assembly 5 is assembled. The connection end portion 51a of each terminal pin 51 is soldered to the terminal portion 41 of the output circuit assembly 4 described above, whereby the electrical connection between the output circuit assembly 4 and the terminal pin assembly 5 is established. Made.
[0046]
Details of the receptacle case 6 are shown in the sectional view of FIG. 8, the perspective view of FIG. 9, and the plan view of FIG. 8 is an enlarged view of the receptacle case shown in FIG. 1, FIG. 9 (a) shows a shape of the receptacle case as viewed from diagonally rear, and FIG. 9 (b) shows a shape of the receptacle case 6 as viewed from diagonally forward. 10A shows the shape of the receptacle case as viewed from the rear, and FIG. 10B shows the shape of the receptacle case 6 as viewed from the front.
[0047]
The receptacle case 6 is a cylindrical body having a flange 60 at the rear end, and is press-fitted into the rear end of the outer shell case 1 to support the external plug and the terminal pin assembly 5 on the outer shell case 1. A part of the collar portion 60 constitutes a fitting portion 60a that is fitted into a notch 11 (see FIG. 1) provided at the rear end portion of the outer shell case 1 when being pressed into the outer shell case 1. The fitting portion 60a is used to position the outer shell case during press-fitting. In addition, the receptacle case 6 has a raised portion 61 provided so as to go around the inner periphery of the central portion, and a space surrounded by the inner peripheral surface of the raised portion 61 serves as a joint portion into which the pin holder portion 50 is press-fitted. Storage space 64 (see FIG. 8). That is, the raised portion 61 is formed so that the inner diameter of the accommodation space 64 is substantially equal to the outer diameter of the pin holder portion 50, and a pair of protruding pieces facing each other on the inner peripheral surface of the raised portion 61. 61 a and 61 b are provided, and the projecting pieces 61 a and 61 b are fitted into the notches 503 and 503 of the pin holder portion 50, and at the same time, the pin holder portion 50 is press-fitted into the receiving space 64, whereby the pin holder portion 50 is inserted into the receptacle case 6. The (terminal pin assembly 4) is integrated (see FIG. 1 and the like).
[0048]
Further, the internal cavity of the receptacle case 6 is partitioned into a front cavity 62 and a rear cavity 63 with the raised portion 61 (accommodating space 64) interposed therebetween. The rear cavity 63 constitutes a plug insertion port, and the terminal pin 51 of the terminal pin assembly 4 is disposed (see FIG. 1). 8 to 10, reference numeral 65 denotes a rail-like protrusion for preventing movement of the plug inserted into the plug insertion port 63 around the shaft, and is provided on a plug (not shown). It is fitted with the predetermined groove.
[0049]
The assembly procedure of the proximity sensor in this embodiment is shown in the flowchart of FIG. As shown in the flowchart, in the present embodiment, first, the output circuit assembly 4 and the terminal pin assembly 5 (with pipe) are electrically connected (step 1101). At that time, as described above, first, the side edges of the substrate 42 of the output circuit assembly 4 are inserted into the pair of fitting grooves (501, 501 or 502, 502 (see FIG. 6)) provided in the pin holder portion 50. The portion (see FIG. 2) is fitted, and the pin holder portion 50 (terminal pin assembly 5) is roughly positioned with respect to the output circuit assembly 4. Thereafter, each connection end portion 51 a (see FIG. 5) of the terminal pin 51 is soldered to each terminal portion 41 provided in the output circuit assembly 4. As a result, the terminal pin assembly 5 is attached to the output circuit assembly 4 without wobbling and is electrically connected.
[0050]
Next, the detection end module 2 and the output circuit assembly 4 are bridged and connected by the connection member 3 (step 1102). This connection is achieved by thermocompression bonding both edges of the connection member 3 to terminal pad portions (not shown) provided in the detection circuit assembly 21 and the output circuit assembly 4 using solder or a conductive adhesive. Done. Thereby, an electrical connection completed product (assembled product) in which the detection end module 2, the connection member 3, the output circuit module 4, and the terminal pin assembly with pipe 5 are connected in series is obtained.
[0051]
Next, the above-mentioned electrical connection completed product is inserted into the outer shell case 1 from the front end opening of the outer shell case 1 with the terminal pin assembly with pipe 5 at the top, and the detection end module 2 is inserted into the outer shell case 1. The electrical connection completed product is attached to the outer shell case (step 1103). In this state, since the electrical connection completed product is only attached to the outer shell case 1 on the detection end module side, the terminal pin assembly 5 on the other side is connected to the connection member 3. Within the allowable range of expansion and contraction, the outer shell case 1 can be moved to a free position.
[0052]
Next, the pipe 52 of the terminal pin assembly with pipe 5 is pulled out from the rear end opening of the outer shell case 1, and the pipe 52 is inserted from the front end opening of the receptacle case 6 (step 1104). As is apparent with reference to FIGS. 1 and 7, the total length of the pipe 52 in the longitudinal direction is approximately twice the total length of the receptacle case 6 in the longitudinal direction. Accordingly, in this example, the projecting pieces 52 a to 52 b of the pipe 52 can be pulled out from the rear end opening of the receptacle case 6 before the pin holder portion 50 is press-fitted into the receiving space 64 of the receptacle case 6.
[0053]
Next, the receptacle case 6 is inserted from the rear end opening of the outer shell case 1 with the pipe 52 inserted, and is press-fitted into the outer shell case 1 (step 1105). As a result, the detection end module 2, the connecting member 3, the output circuit assembly 4, the terminal pin assembly 5 and the receptacle case 6 are accommodated in the outer shell case 1.
[0054]
Next, by operating the pipe 52 projecting from the rear end opening of the receptacle case 6, the pin holder portion 50 accommodated in the outer shell case is applied to the accommodation space 40 of the receptacle case 6 and pulled, whereby the terminal pin The assembly 5 is press-fitted into the receptacle case 6 (step 1106), whereby a completed product (intermediate product of proximity sensor) in a state where all the sensor components are positioned and attached to the outer shell case 1 is obtained. It is done.
[0055]
Next, a sealing process of filling the resin into the outer shell case 1 of the finished product is performed (step 1107). As described above, this sealing process is performed through a resin inflow path formed by the through hole 520 of the pipe 52 and the through hole 500 of the pin holder portion 50. More specifically, a nozzle of a funnel type resin injection hopper (not shown) composed of a resin receiving port and a resin outflow nozzle is inserted into the through hole 520 of the pipe 52, and the resin receiving port of the resin injection hopper is placed in the resin receiving port. Pour a certain amount of filling resin. After that, the hopper integrated type finished product is gradually tilted and shifted to a horizontal state, and the hopper is rotated around the vertical axis toward the center side. As a result, centrifugal force is applied, resin flows into the outer shell case 1 through the resin inflow path of the hopper and the terminal pin assembly 5, and the air in the outer shell case 1 is discharged, whereby the outer shell case 1 is discharged. The resin can be filled in 1 with almost no air remaining. For this reason, the outer shell case 1 shown in the present embodiment does not require an air discharge duct or the like for filling the resin.
[0056]
Next, a sealing method in the proximity sensor of the electric cord attaching / detaching method will be described in detail with reference to FIGS. FIG. 12 shows a flowchart showing a sealing process applied to a cord detachable proximity sensor. As shown in the figure, in the sealing method of the present invention, a predetermined jig is first attached to an intermediate product of a proximity sensor that has been assembled (step 1201), and then this jig is used. Then, the intermediate product of the proximity sensor and the resin reservoir hopper are connected (step 1202).
[0057]
FIG. 13 shows an exploded perspective view for explaining the relationship between the proximity sensor, the hopper, and a jig for coupling and holding them. In the figure, 100 is a proximity sensor that is an intermediate product that has been assembled, 7 is a resin hopper, 8 is a first half of a jig, 9 is a second half of the jig, and these two halves 8 , 9 are coupled face to face to constitute a jig for connecting the proximity sensor 100 and the resin reservoir hopper 7.
[0058]
That is, the jig includes a first half 8 and a second half 9 each having a half-cylindrical shape. The first half 8 of the jig is provided with a cylindrical inner wall 81, a conical inner wall 82, an opening 83, a small diameter groove 84, a through hole 85, and a large diameter groove 88 in order from the top. . Similarly, the second half 9 of the jig is also provided with a similar cylindrical inner wall 91, conical inner wall 92, opening 93, small diameter groove 94, through hole 95, and large diameter groove 98. ing. In addition, pins 86 and 87 protrude from the first half 8 side, and through holes 96 and 97 into which the pins 86 and 87 are inserted into the second half 9 of the jig opposite thereto. Is provided.
[0059]
Further, at positions of the first half 8 and the second half 9 facing each other, through holes 85 and 95 for inserting the thin plate-like regulating pieces 10 are provided, respectively. The thin plate-shaped regulating piece 10 is engaged with the protrusions 52b and 52b of the resin injection pipe 82 to prevent the proximity sensor 100 from coming off. The thin plate-shaped restricting piece 10 is formed with a left branch finger portion 10b and a right branch finger portion 10c with a cut groove 10a interposed therebetween. The width of the cut groove 10 a is set slightly larger than the outer diameter of the resin injection pipe 52.
[0060]
Further, the widths of the small diameter grooves 84 and 94 are set slightly larger than the outer diameter of the resin injection pipe 52, and at the same time, the widths of the large diameter grooves 88 and 98 are larger than the outer diameter of the rear large diameter portion of the proximity sensor 100. It is set slightly larger. Therefore, in the intermediate product of the proximity sensor 100, the resin injection pipe 52 is fitted into the small diameter grooves 84 and 94, and the large diameter portion of the outer shell case 1 of the proximity sensor 100 is fitted into the large diameter grooves 88 and 98. 8 and the second half 9 are connected in a face-to-face state, the pins 86 and 87 protruding from the first half 8 side are inserted into the through holes 96 and 97 on the second half 9 side. Is firmly positioned and fixed.
[0061]
After that, if the thin plate-like regulating piece 10 is inserted into the through holes 95, 85 from the second half 9 side to the first half 8 side, it is between the left branch finger portion 10b and the right branch finger portion 10c. The resin injection pipe 52 is inserted into the formed cut groove 10a, and at the same time, the protrusions 52b and 52b of the resin injection pipe 52 are engaged with the left branch finger portion 10b and the right branch finger portion 10c of the thin plate-shaped restricting piece 10. Thus, the resin injection pipe 52 is restricted from moving in the direction of the distal end of the proximity sensor 100 and is fixed to prevent the resin injection pipe 52 from coming off.
[0062]
In this state, the cylindrical inner wall 81 on the first half 8 side faces the cylindrical inner wall 91 on the second half 9 side, and further, the conical inner wall 82 on the first half 8 side and the cone on the second half 9 side. A space for accommodating the resin reservoir hopper 7 is formed by the opposing inner wall 92.
[0063]
On the other hand, the resin reservoir hopper 7 includes a cylindrical portion 71, a conical portion 72, a straight pipe portion 73, and an opening 74 in order from the top. Such a funnel-shaped hopper 7 fits snugly into a space formed by the two cylindrical inner walls 81 and 91 and the conical inner walls 82 and 92 described above. In the state in which the resin reservoir hopper 7 is fitted, the lower end opening 74 of the straight pipe portion 73 is closely aligned with the upper end opening 520 of the resin injection pipe 52, and the both fit firmly. As a result, a resin inflow path from the resin reservoir hopper 7 through the resin injection pipe 82 into the outer shell case 1 of the proximity sensor 100 is completed.
[0064]
Returning to the flowchart of FIG. 12, in the next step, the resin is poured into the resin reservoir hopper 7. The amount of the flowing resin is slightly larger than the capacity of the void formed inside the proximity sensor 100. This is because when the resin hardens and shrinks, the shrinkage can be compensated by the fluidized resin accumulated in the hopper 7. In this example, a thermosetting resin (for example, a thermosetting urethane resin) is used as the fluid resin. Since the amount of resin to be poured may be rough, it is only necessary to discharge an approximate amount from the nozzle of the resin extraction device into the resin reservoir hopper 7, so that it is not necessary to manage the process so precisely. Of course, when discharging the flowing resin into the resin reservoir hopper 7, it is preferable that the proximity sensor 100 and the resin reservoir hopper 7 be supported in an upright or almost upright state.
[0065]
In the next step, as shown in FIGS. 14 and 15, an assembly formed by coupling the proximity sensor 100 and the resin reservoir hopper 7 via the jigs 8 and 9 is set in the centrifugal force application device ( Step 1204). As shown in FIG. 15, the centrifugal force application device 100 includes a motor 131, a rotating shaft 132 that rotates vertically with the rotational force of the motor 131, and a horizontal swing attached to the upper end of the rotating shaft 132. The arm 133 and the swing container 110 suspended swingably at both ends of the swing arm 133 are included. The support shaft 111 of the swinging container 110 is directed in the tangential direction of the rotation locus drawn by the swing arm 133. Therefore, when the motor 131 is activated and the rotating shaft 132 rotates, as shown by the phantom line in the figure, the swinging container 110 gradually begins to tilt due to centrifugal force, and is indicated by reference numeral 11a at the prescribed maximum rotation speed. Thus, the rotation is continued with the horizontal posture.
[0066]
On the other hand, as shown in FIG. 14, the proximity sensor 100 is mounted in the swinging container 110 with its tip portion vertically downward. In the figure, 120 is a rotation center line of the support shaft 111. Also, from this figure, as described above, the protrusions 52b and 52b of the resin injection pipe 52 are engaged with the left branch finger portion 10b and the right branch finger portion 10c, so that the resin injection pipe 52 is prevented from being detached. The state is shown.
[0067]
In the next step, the motor 131 is started in the centrifugal force application device 130, and centrifugal force is applied in the distal direction of the proximity sensor 100 to the proximity sensor 100 and the flowing resin in the resin reservoir hopper 7 (step). 1205). As described above, the assembly formed by coupling the proximity sensor 100 and the resin reservoir hopper 7 through the jigs 8 and 9 is placed in the swinging container 110 so that the tip of the proximity sensor 100 faces downward. After that, when the motor 131 is started and the swing arm 133 swings at a predetermined speed, as shown in FIG. 15, the swinging container 110 gradually moves in the horizontal direction as the number of rotations increases. As a result, the flow resin discharged to the resin reservoir hopper 7 passes through the resin injection pipe 52 and the through hole 500 of the pin holder portion 50, as shown in FIG. It is forcibly injected into 1. Then, in the outer shell case 1, due to the difference in mass between the fluid resin and the air, the air filling the void in the outer shell case 1 and the poured fluid resin are forcibly exchanged. Thus, the air retreated from the gap is discharged from the resin reservoir hopper 7 to the atmosphere following the path used for pouring the fluidized resin.
[0068]
That is, according to the present invention, the detection coil assembly 22 and the component-mounted circuit board (the detection circuit assembly 21 and the output circuit assembly 4) are out of the proximity sensor intermediate product in which the outer shell case 1 is incorporated. While applying a centrifugal force toward the tip of the shell case, by pouring the fluid resin from the opening 500 provided in the rear part of the shell case 1, the shell case 1 is utilized by utilizing the mass difference between the fluid resin and air. The exchange of the air filling the gap with the fluid resin poured is forced, and at the same time, the air retreated from the gap by the exchange is naturally discharged from the opening 500 itself used to pour the fluid resin. It is trying to make it.
[0069]
According to such a configuration, the fluid resin injected into the outer shell case 1 is forcibly transferred in the distal direction in the outer shell case 1 by centrifugal force. It is possible to securely seal the built-in circuit components and the like by injecting closely to every corner. On the other hand, the air retreated from the gap by the exchange of the filled resin with the air filling the gap in the outer shell case 1 is naturally discharged from the opening 500 itself used for pouring the fluid resin, It is not necessary to provide a dedicated air discharge path for air venting, and the structure of related parts is simplified correspondingly, thereby contributing to cost reduction of the product.
[0070]
Further, as shown in FIG. 16, in the receptacle case 6, radially outward from the tip protrusion 61 a of the protruding portion 61 protruding in the center direction and the pin holder portion 50 located at the base of the resin injection pipe 52. The protruding tip protrusion 50a engages to prevent both from coming off. At this time, the inner peripheral protrusion 61a on the receptacle case 6 side and the outer peripheral protrusion 50a on the pin holder part 50 side contact each other. Since the force acts on the contact surface of the stepped portion in contact with the centrifugal force F1 in the direction of narrowing the gap between the protrusions 61a and 50a as shown by arrows A1 and A2 in FIG. The resin does not leak from the gap. That is, as the number of rotations of the centrifugal force application device increases and the centrifugal force F1 increases, as shown by arrows A1 and A2, the gap between the two acts more narrowly. Even without adopting a structure or the like, it is possible to prevent the fluid resin from leaking from the gaps. In the resin injection method using the center force of the present invention, the result that the centrifugal force applied to the resin injected into the outer shell case 1 is preferably about 1.4N to 32.7N is obtained. It was. In addition, the time for applying the centrifugal force is sufficient if the fluid resin poured into the outer shell case 1 is filled in a predetermined gap in the outer shell case 1.
[0071]
Subsequently, returning to FIG. 12, when the centrifugal force application process is completed, the assembly of the proximity sensor 100 and the resin reservoir hopper 7 is taken out from the centrifugal force application device 130 (step 1206). The assembly is inserted into a predetermined high-temperature bath while the resin hopper 100 and the resin reservoir hopper 7 are connected to each other. As described above, since the thermosetting urethane resin is employed as the fluid resin, the fluid resin can be cured after a predetermined time by heating in a high temperature bath.
[0072]
When the fluidized resin is cured in this way, the hopper 7 can be threaded together with the resin injection pipe 52 at the fragile portion of the base of the resin injection pipe 52 by twisting the resin injection pipe 52 together with the resin reservoir hopper 7. (Step 1208). Thereby, the sealing process is completed by injecting resin into the outer shell case 1 and curing it.
[0073]
Next, an example in which the sealing method of the present invention is applied to a sealing process of a cord fixed proximity sensor will be described in detail with reference to FIGS. A flow chart showing the sealing process of the cord fixed proximity sensor is shown in FIG. As shown in the figure, in the first step, resin is injected into the hopper under pressure (step 1701).
[0074]
As shown in FIG. 19, in the cord-fixed proximity sensor shown in this example, the rear end opening of the outer shell case 1 is closed by the end plug portion 160, and the end plug portion 160 The rear end portion 43a of the output circuit board 43 protrudes. As will be described later, the protruding portion is provided with a connecting pad portion 41 for connecting a conductor of a core wire drawn from the electric cord. The end plug portion 160 is provided with a first opening 160a and a second opening 160b so as to face each other with the substrate rear end portion 43a interposed therebetween. Further, a first hopper portion 141 communicating with the first opening 160a is integrally formed, and a second hopper portion 142 communicating with the second opening 160b is integrally formed. That is, the first hopper portion 141 and the second hopper portion 142 are integrally formed with the end plug portion 160. The capacities of these hopper portions 141 and 142 are set to an insufficient size to fill the gap in the outer shell case 1 in this example. In addition, in the same figure, the same code | symbol is attached | subjected about the same structure location as each member shown by FIGS. 1-16, and description is abbreviate | omitted.
[0075]
In the above configuration, when the injection nozzle 150 of the resin injection device is brought into close contact with the first hopper 141 and the resin is fed into the first hopper 141, the fed resin flows as shown in the arrow A3. Is forced into the outer shell case 1 through the opening 160a. At the same time, the air present in the outer shell case 1 is discharged from the second hopper portion 142 to the atmosphere through the second opening 160b as indicated by an arrow A4. However, the resin cannot be injected tightly into the fine voids in the outer shell case 1 by this pressure injection. That is, it is difficult to inject the resin evenly into the fine gaps in the outer shell case 1 with only the pressure from the injection nozzle 150. In particular, it is difficult to spread the resin evenly between the outer shell case 1 and the coil case, and between the circuit board and various electronic components. Invitation of water causes deterioration of characteristics. When the resin is injected from the injection nozzle 150 by pressure, the resin injection is completed after the resin injected from the first hopper 141 overflows from the second hopper 142.
[0076]
Subsequently, as shown in FIG. 17, the proximity sensor in which the resin is once filled in the outer shell case 1 is set in the centrifugal force application device (step 1702). Here, the configuration of the centrifugal force application device has been sufficiently described above with reference to FIGS.
[0077]
Subsequently, in the next step, the centrifugal force application device is activated to apply a centrifugal force to the set proximity sensor (step 1703). Then, in the same manner as in the previous example, centrifugal force is applied to the resin filled in the outer shell case 1 toward the distal end of the proximity sensor, and the injected resin is fine in the outer shell case 1. The air that enters the gap and is simultaneously withdrawn from the gap moves to the rear end side of the outer shell case 1 due to the mass difference between the resin and the air, and passes through the first opening 160a or the second opening 160b. It is discharged from the hopper 141 or the second hopper 142 to the atmosphere. That is, in this example, during the pressure injection of resin, the first hopper 141 is used for resin injection and the second hopper 142 is used for discharging air, while the centrifugal In the step of spreading the resin evenly in the outer shell case 1 by applying a force, both the first hopper portion 141 and the second hopper portion 142 are used for exhaustion and are generated from the outer shell case 1. Can be exhausted naturally into the atmosphere.
[0078]
Thereafter, as shown in FIG. 17, the proximity sensor is taken out from the centrifugal force application device (step 1704), and inserted into a high-temperature bath to cure the injected resin (step 1705), and the curing is completed. Then, the first hopper part 141 and the second hopper part 142 are cut off from the base part (step 1706), and the sealing process is completed.
[0079]
Thereafter, as shown in FIG. 20, the conductors 400-1 a and 400-2 a of the core wires 400-1 and 400-2 drawn from the electric cord 400 are provided at the rear end portion 43 a of the output circuit board 43. When the cord protector 401 is formed by using a resin molding technique, the cord fixing proximity sensor is completed.
[0080]
By the way, although the capacity | capacitance of the 1st hopper part 141 and the 2nd hopper part 142 which were shown by FIG. 18 and FIG. 19 was inadequate size to fill the space | gap in the outer case 1, the total capacity | capacitance of both hoppers Is sufficiently large to fill the gap in the outer case 1, the cord-fixed proximity sensor is applied to both hoppers before applying centrifugal force, as described with reference to FIGS. A method can be implemented in which the fluid resin is stored and the resin in the hopper is injected into the outer case by applying centrifugal force. Instead of using two hoppers, a single hopper having a sufficient capacity to fill the gap in the outer case 1 can be used. The method for sealing the proximity sensor is described as follows.
[0081]
That is, the proximity sensor intermediate product in which the detection coil assembly and the component mounting circuit board are incorporated in the outer shell case is provided at the rear portion of the outer shell case while applying a centrifugal force toward the distal end of the outer shell case. By pouring the fluid resin from the opening, the mass difference between the fluid resin and air is used to forcibly exchange the air filling the void in the outer shell case with the fluid resin that has been poured. Therefore, the air retreated from the gap is naturally discharged from the opening itself used for pouring the fluid resin.
[0082]
In the proximity sensor, the connection pad provided at the rear end of the component mounting circuit board is projected from the end plug that closes the rear end opening of the outer shell case, while the conductor of the core wire drawn from the electrical cord is Connected to the connecting pad portion, and then corresponds to a proximity sensor of a cord fixing type formed by resin molding a cord protector that encloses between the rear end face of the end plug and the outer end of the outer portion of the electric cord. .
[0083]
Specifically, the intermediate product of the proximity sensor includes a cylindrical outer shell case, a detection coil assembly that closes the front end opening of the outer shell case, an end plug that closes the rear end opening of the outer shell case, A component mounting circuit board in which the connection pad portion provided in the rear end portion of the outer shell case penetrates the end plug and protrudes to the outside, and the end plug has an opening and the opening The resin reservoir hopper that is connected to is integrally molded.
[0084]
On the premise of the proximity sensor intermediate product having such a structure, processing is performed according to the following first to fourth steps. That is, in the first step, in the state where the proximity sensor intermediate product is almost upright with the tip portion down, the flow resin is discharged into the resin reservoir hopper by an amount that slightly exceeds the capacity of the void in the outer shell case. Let In the subsequent second step, the proximity sensor intermediate product is attached to the centrifugal force application device, and the centrifugal force is applied toward the tip of the proximity sensor intermediate product. In the subsequent third step, the proximity sensor intermediate product is removed from the centrifugal force application device, and the resin injected and filled in the outer shell case is cured. In the fourth step, the resin reservoir hopper is cut off after the resin injected and filled in the outer shell case is cured.
[0085]
【The invention's effect】
As is clear from the above description, according to the proximity sensor sealing method of the present invention, the fluid resin injected into the outer shell case is forcibly transferred to the tip direction in the outer shell case by centrifugal force. Therefore, the fluidized resin can be injected tightly into every corner of the outer shell case to securely seal the built-in circuit components and the like. On the other hand, air that has been retreated from the gap due to the exchange of the air filling the gap in the outer shell case with the poured fluid resin is naturally discharged from the opening itself used to pour the fluid resin. Therefore, it is not necessary to provide a dedicated air discharge path, and the structure of related parts is simplified correspondingly, thereby contributing to cost reduction of the product.
[0086]
Further, according to the proximity sensor sealing method of the present invention, the fluid resin is poured from the first opening provided at the rear portion of the outer shell case while being pressurized, and from the second opening provided at the rear portion of the outer shell case. By letting out the retreated air, the work of filling the flowable resin into the outer shell case for the time being can be performed quickly using a pressure injection device. On the other hand, the step of allowing the flowing resin to enter every corner of the outer shell case can be reliably performed using a centrifugal force application device. At this time, the air retreated from the gap by the exchange of the air filling the gap in the outer shell case and the poured fluid resin is the opening used for pouring the fluid resin and the opening used for discharging the resin. Since the air is naturally discharged from both sides, the air can be discharged more reliably by a simple process than when the air in the outer shell case is sucked. In addition, since the fluid resin is already filled in the outer shell case when the centrifugal force is applied, the structure for injecting the fluid resin such as a large hopper is not required in the step of applying the centrifugal force. .
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a cord detachable proximity sensor.
FIG. 2 is a diagram showing an internal structure of a cord detachable proximity sensor.
3 is a cross-sectional view taken along line BB in FIG.
4 is a cross-sectional view taken along line CC in FIG.
FIG. 5 is an overall perspective view showing a structure of a terminal pin assembly (with a pipe).
FIG. 6 is an end view of a terminal pin assembly (with a pipe).
7 is a cross-sectional view taken along line DD of FIG.
FIG. 8 is a cross-sectional view showing the structure of a receptacle.
FIG. 9 is a perspective view showing a structure of a receptacle.
FIG. 10 is a diagram showing a structure of a receptacle.
FIG. 11 is a flowchart showing a method for producing a proximity sensor.
FIG. 12 is a flowchart showing a sealing process of the cord detachable proximity sensor.
FIG. 13 is an exploded perspective view for explaining the relationship between a proximity sensor, a hopper, and a jig that holds them together.
FIG. 14 is an explanatory diagram of a state in which a proximity sensor with a hopper is housed in a rocking container of a centrifugal force application device.
FIG. 15 is a conceptual diagram for explaining a configuration of a centrifugal force application device.
FIG. 16 is an explanatory diagram of a resin leakage preventing action when a centrifugal force is applied.
FIG. 17 is a flowchart showing a sealing process of the cord fixed proximity sensor.
FIG. 18 is a diagram showing a state of assembly completion (immediately before sealing) of the cord-fixed proximity sensor.
FIG. 19 is a cross-sectional view showing a state in which the assembly of the cord-fixed proximity sensor is completed (immediately before sealing).
FIG. 20 is a diagram showing a state after the cord protector of the cord fixed type proximity sensor is molded.
FIG. 21 is an explanatory diagram of electrical code format types of proximity sensors.
[Explanation of symbols]
1 outer shell case
2 Detection end module
3 connecting members
4 Output circuit assembly
5 Terminal pin assembly
6 Receptacle case
7 Resin reservoir hopper
8 First half of jig
9 Second half of jig
10 Thin plate-shaped regulating piece
10a Infeed groove
10b Left branch finger
10c Right branch finger
11 Notch
20 Coil case
21 Detection circuit assembly
22 Detection coil assembly
22a coil
22b Ferrite core
23 Terminal piece
24 Mask conductor
41 Terminal
42 Side edge
43 Output circuit board
43a Rear end of output circuit board
50 Pin holder
50a Outer protrusion of pin holder
51 terminal pin
51a, 51b Connection end
52 Pipe for resin injection
52b Locking protrusion
60 buttock
60a Fitting part
61 Uplift
61a Inner protrusion of the raised part
62 Forward cavity
63 Back cavity (plug socket)
64 storage space
65 Sealed protrusion
71 Cylindrical part
72 Cone
73 Straight pipe
74 opening
81 Cylindrical inner wall
82 Conical inner wall
83 opening
84 Small-diameter groove
85 Through hole
86, 87 pins
88 Large diameter groove
91 Cylindrical inner wall
92 Conical inner wall
93 opening
94 Small-diameter groove
95 Through-hole
96,97 through-hole
98 Large diameter groove
110 Oscillating container
111 spindle
120 center line
130 Centrifugal force application device
131 motor
132 Rotating shaft
133 Swivel arm
141 First hopper
142 Second hopper
150 Injection nozzle
160 End plug part
160a first opening
160b second opening
400 Electric cord
400-1, 400-2 core wire
400-1a, 400-2a conductor
401 Code protector
500 Through hole
501,502 Mating groove
520 Through hole (opening)
F1 Arrow indicating centrifugal force
A1, A2 Arrows indicating the force acting on the resin leakage gap
A5 Arrow indicating exhausted air

Claims (1)

From the opening provided at the rear of the outer shell case while applying centrifugal force to the proximity sensor intermediate product in which the detection coil assembly and the component mounting circuit board are incorporated in the outer shell case By pouring the fluid resin, the mass difference between the fluid resin and air is used to forcibly exchange the air filling the void in the outer shell case with the poured fluid resin. A proximity sensor sealing method in which air retreated from the air is naturally discharged from the opening itself used for pouring the fluid resin ,
The proximity sensor intermediate product corresponds to a proximity sensor of an electrical cord attachment / detachment system that is detachable through a receptacle fixed to the outer shell case side and a plug fixed to the electrical cord side,
A cylindrical outer shell case, a detection coil assembly for closing the front end opening of the outer shell case, a receptacle with a terminal pin for closing the rear end opening of the outer shell case, and a detection coil assembly in the outer shell case And a component-mounted circuit board disposed between the terminal pin built-in receptacle and the terminal pin built-in receptacle, and the terminal pin built-in receptacle is provided with an opening used both as a resin spout and an air escape port,
The method comprises
The resin hopper is connected to the rear end of the proximity sensor intermediate product with a predetermined jig so that the outlet of the resin reservoir hopper is opened and the terminal pin built-in receptacle is also used for injection and exhaust A first step of communicating with
A second step of discharging the fluid resin into the resin reservoir hopper by an amount somewhat exceeding the capacity of the gap in the outer shell case in a state in which the proximity sensor intermediate product is almost upright with the tip portion down;
A third step of attaching a combined body of the proximity sensor intermediate product and the resin reservoir hopper to the centrifugal force application device, and applying a centrifugal force toward the distal end of the proximity sensor intermediate product;
A fourth step of removing the combination of the proximity sensor intermediate product and the resin reservoir hopper from the centrifugal force application device and curing the resin injected and filled in the outer shell case,
The terminal pin built-in receptacle is a cylindrical receptacle case that is press-fitted into the rear end of the outer shell case, and is inserted into the receptacle case from the front end side toward the rear end side and contacts the step on the inner periphery of the receptacle case. A terminal pin assembly that is prevented from advancing in contact with, and
The terminal pin assembly includes a plurality of parallel pins serving as terminal pins with built-in receptacles, a pin holder for bundling and holding the plurality of pins, and a resin injection pipe portion to be cut connected to a through hole in the center of the pin holder; Has a structure formed by integrally molding,
In the first step, the resin reservoir hopper is attached to a predetermined jig at the rear end of the proximity sensor intermediate product so that the front end opening of the resin injection pipe and the outflow side opening of the resin reservoir hopper are joined. Combined
In the third step, when the centrifugal force is applied by attaching the combined body of the proximity sensor intermediate product and the resin reservoir hopper to the centrifugal force application device, the terminal pin assembly applies the centrifugal force via the resin injection pipe. The receptacle case integrated with the outer shell case, while being integrally fixed to the device, is slidable with respect to the terminal pin assembly,
Thereby, when a centrifugal force is applied, the centrifugal force acts in a direction in which a resin leakage gap formed between the pin holder of the terminal pin assembly and the step portion on the inner periphery of the receptacle case is narrowed. A proximity sensor sealing method.

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