JP4768586B2 - Sensor with signal cable and method of manufacturing the sensor - Google Patents

Description

  The present invention relates to a sensor with a signal cable such as a rotation speed sensor with a signal cable attached, and a method for manufacturing the sensor.

  A sensor with a signal cable attached by connecting a signal cable for signal transmission to a sensor IC is practically used as a rotational speed sensor for detecting the rotational speed of a vehicle axle or the like, for example.

As the rotational speed sensor, for example, there is one disclosed in Patent Document 1 below. In the rotation speed sensor (rotation detection device) disclosed in Patent Document 1, a joint portion of a conductor composed of a stranded wire of a signal transmission line (signal cable) with a sensor IC (rotation detection IC) side terminal is previously resisted. The terminal is solidified by welding (claim 10), and the terminal and the solidified conductor are joined by microtig welding (claim 1).
Further, the transmission line has a curved portion (Claims 5 and 6), and when the resin housing is formed to cover the periphery of the rotation detecting portion, the bending portion absorbs the tensile force acting on the joint portion between the transmission line and the terminal. I try to suppress it.

On the other hand, in Patent Document 2 below, the ends of a conductor composed of twisted wires of a flat cable are partially heated and melted by metal plating applied to the strands of the twisted wire to fuse and solidify the wires to each other. Thus, a technology for making a single wire is disclosed, and this technology can also be applied to a signal cable having a stranded wire conductor.
JP 2004-251885 A Japanese Patent Publication No.7-118224

  The joint part with the terminal of the stranded wire formed by the technique of Patent Document 1 is a weld ball, and the terminal of the conductor made into a single wire by the method of Patent Document 2 has a round shaft shape. Both techniques have the problem that joining is very difficult.

  Terminals and stranded wires that are joined to each other, when the width of the terminal to be joined is narrow and the outer diameter of the stranded wire is small, the overlapping area becomes very narrow, and the movement and deformation of the overlapping terminals and stranded wires are also reduced. Because it is easy to occur, it is difficult to hold the state stably with high accuracy and accuracy, which causes the joining area to shift and the uniformity of the joining part to be impaired, and failure loss (defective product) Increasing the cost will adversely affect the cost.

  Furthermore, when joining by soldering, the area to which the tip of the soldering iron is applied cannot be applied and a sufficient amount of heat cannot be applied. On the other hand, in the case of welding, if the joining area is small, Since the stranded wire itself is thin and stress concentration due to deformation or the like is likely to occur near the welded portion of the stranded wire and 100% of the base material strength cannot be obtained, it is difficult to ensure the bonding strength.

  In addition, a signal cable core with a bent portion requires a bending process of the core, and needs to be bent using a hot press to maintain the bent state. There is also a drawback that becomes higher.

  In order to solve the above-described problems, an object of the present invention is to easily and surely make electrical connection to a sensor element of a signal cable having a stranded conductor.

In order to solve the above problems, in the present invention, a signal comprising a signal cable in which a conductor is formed of a stranded wire, a sensor element having a terminal for connecting the signal cable, and a resin holder for holding the sensor element. The sensor with cable is constructed as follows.
(A) A sensor element in which a stranded wire (conductor) of a signal cable is provided with a single wire portion fused and integrated into a flat plate shape, and the single wire portion is held by a resin holder It has a structure in which the periphery is solidified with mold resin.
(B) The joining of the single wire portion to the terminal is performed by soldering,
The surrounding area is covered with solder.
(C) The single wire portion is overlapped with the terminal in a state in which the allowance W on one side in the width direction from the side surface of the terminal is at least the height H of the terminal. Solder fillets are formed in regions along the upper surface and the side surfaces of the terminal.
(D) The single wire portion is placed on a part of the resin holder, and the terminator is further placed on the single wire portion.
Null is overlapped and soldered to the single wire section, and heat is applied to the portion where the resin holder covers the solder section.
The resin holder and the single wire unit are bonded to each other by fusion bonding.

The sensor with signal cable constructed in this way has a flat single wire section formed on the stranded wire, so even if the terminal width is narrow and the stranded wire diameter is small, the sensor is connected to the single wire. The parts can be stably stacked and securely joined. When the terminals are overlapped and joined, the allowable positional deviation amount in the width direction of both is increased, so that high positioning accuracy is not required, and joining processing becomes easy. Therefore, failure loss is reduced and the quality of the joint is stabilized.
Further, with the configuration B, when the single wire portion and the terminal are joined by soldering, the periphery of the joint portion is covered and reinforced with solder, and the joint strength of the joint portion is increased. As a result, disconnection failures are reduced and reliability is increased.
Furthermore, with the configuration of C, a solder fillet that is as large and stable in shape as possible can be formed on the upper surface of the protruding portion in the width direction of the single wire portion and the region along the side surface of the terminal. The durability reliability of the part can be further increased.
Furthermore, with the configuration of D, when a tensile force is applied to the cable, the force is received by the resin holder, and the force is suppressed from being transmitted to the joint between the terminal and the single wire portion and the sensor element. Since joint and protection from tensile force can be realized at the same time, processing costs can be reduced. Further, it is not necessary to provide a bent portion for generating a locking force on the core wire, and accordingly, space and material costs can be saved, and the sensor can be reduced in size and cost.

  The preferred configurations are listed below.

(E) On the surface of the portion where the resin holder of the single-wired portion is heat-sealed, minute irregularities are formed such that the depth of the concave portion and the height of the convex portion are less than 0.5 mm.
The anchor effect due to the minute unevenness increases the bonding strength between the resin holder and the cable conductor, so that a better effect can be expected.
(F) The sensor is a rotational speed sensor that detects the rotational speed of a rotating body such as an axle.

In this invention, the manufacturing method of said sensor with a signal cable is also provided collectively.
The sensor is manufactured by applying pressure and ultrasonic vibration to the stranded wire of the signal cable to fuse and unify the strands of the stranded wire to form a single wire portion formed into a flat plate shape on the stranded wire. The single wire section is joined to the terminal of the sensor element held by the resin holder, and then the periphery is solidified with mold resin. In this method, a part of a stranded wire is made into a single wire in an intended size and shape by using a horn or a support member for applying ultrasonic vibration as a mold.

In this method, since the bonding of the single-wire portion relative to the terminal of the sensor element by soldering, thereby fusing the resin holder in the single-wire portion by dissolving the contact to the single-wire portion of the resin holder in the heat during soldering It does not require a special process for fusion.

  In addition, the formation method of the single wire | line part of the strand wire mentioned above is applicable to all the signal cables which have a strand wire.

  In the sensor with a signal cable according to the present invention, as described above, a flat single wire portion is formed on the conductor (stranded wire) of the signal cable, and the single wire portion is joined to the terminal of the sensor element. Even when the width is narrow and the twisted wire diameter is small, the terminal and the single wire forming portion formed in a plate shape can be stably overlapped and reliably joined. Since the width of the single wire portion is secured, when the terminals are overlapped and joined, the allowable positional deviation amount in the width direction of both is increased, so that high positioning accuracy is not required, and joining processing becomes easy. Therefore, failure loss is reduced and the quality of the joint is stabilized.

  Further, according to the method for manufacturing a sensor with a signal cable of the present invention, a part of a stranded wire is simply and surely made into a single wire having a desired size and shape by using a horn or a support member for applying ultrasonic vibration as a molding die. can do.

  Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows the procedure for joining the sensor element (sensor IC) 1 and the signal cable 3 for easy understanding.

The sensor element 1 has two terminals 2. Moreover, the signal cable 3 is used in which the conductor of each core wire 4 is formed by the stranded wire 5. The outer sheath 6 of the cable and the insulation coating 7 of the core wire are peeled to expose the stranded wire 5 of a predetermined length at the terminal, and the single-wire portion 8 shown in FIG. 1B is formed on the exposed stranded wire 5. Then, as shown in FIG. 1C, the sensor element terminal 2 is overlapped on the single wire forming portion 8, and the overlapping portion is soldered and joined. Reference numeral 9 in FIG. 1D denotes a solder fillet formed at the joint.

  FIG. 1E shows an enlarged cross-sectional view at a position along A-A in FIG. As a preferred structure, the single wire portion 8 is overlapped with the terminal 2 with the allowance W on one side in the width direction from the side surface of the terminal 2 being at least equal to or higher than the height H of the terminal 2, and the allowance portion in the width direction is overlapped. A fillet of solder 9 is formed in a region along the upper surface and the side surface of the terminal 2. Thus, when the relationship between the protrusion W from the terminal side of the single wire portion and the terminal height H is set to W> H, a large solder fillet with a stable shape can be formed, and the reinforcement effect by the solder is great. This increases durability and reliability.

  FIG. 2 shows a specific example of a sensor with a signal cable. The illustrated sensor is a rotation speed sensor and includes a resin holder 10 formed of a thermoplastic resin. The resin holder 10 includes a main body portion 11 and a resin cover 12 that covers the upper side of the main body portion. The resin cover 12 has a pair of opposed arms 12a on both sides, and the arms 12a function as check claws and are fixed to both sides of the main body 11 and attached to the main body 11.

  The main body part 11 has each holding part 11a, 11b of the sensor element and the conductor single wire part, a partition wall 11c that insulates between the two electrical connection parts, and two holes 11d, and the signal cable The single wire portion 8 formed on the stranded wire 5 is positioned and placed on the two holding portions 11b and 11b, and the terminal 2 is passed through the hole 11d to position the sensor element 1 between the opposing side walls of the holding portion 11a. Pay. The single-wire unit 8 has a surface provided with fine irregularities 13 such as knurls. The minute irregularities referred to here are such that the depth of the concave portions and the height of the convex portions are less than 0.5 mm. Even when the depth of the concave portion or the height of the convex portion is 0.1 mm or less, specifically, about 0.05 mm, the effect of the concave and convex arrangement is recognized.

  In this state, the terminal 2 overlaps the single wire unit 8. Therefore, as shown in FIG. 2B, the resin cover 12 is attached, and the single wire portion 8 and the terminal 2 overlaid thereon are soldered and joined. The terminal 2 is thin and easy to deform, but since the width of the single wire portion 8 is secured, the overlapping state required for joining is not required even if the terminal 2 is deformed and the displacement does not become so large. Is maintained. Therefore, soldering becomes easy, and the quality of the obtained joint part also increases. Moreover, since the fillet of the solder 9 having a large and stable shape as shown in FIG. 1 (e) is formed on the left and right sides of the joint, the joint strength is sufficiently secured and the durability reliability is increased.

  Furthermore, the holding portion 11b of the resin holder 10 is melted by heat at the time of soldering and is fused to the surface of the single wire forming portion 8. The joining strength between the single-wire section (cable conductor) and the resin holder 10 is increased by the engaging action of the minute irregularities 13 formed on the surface of the single-wire section 8 with the resin.

  When the joining of the stranded wire of the signal cable 3 and the terminal 2 is completed, the outer side of the resin holder 10 is hardened with a mold resin 14 as shown in FIG. The mold resin 14 is molded so as to have necessary dimensions and shapes to constitute the sensor body. In the illustrated sensor with signal cable, the mounting bracket 15 is integrally provided at that time. However, the mounting bracket 15 is provided as necessary, and a sensor without this bracket is also available. Conceivable.

3 and 4 show a method of forming the single wire portion 8 in the stranded wire of the signal cable. This method uses a single-wire unit forming apparatus 20 that combines a terminal ultrasonic bonding apparatus for a stranded wire 5 (only the horn 16 is shown), a pair of left and right support blocks 17 and a pair of left and right clamping blocks 18. The procedure is as follows.
1) Place the stranded wire 5 exposed at the end of each core of the signal cable 3 on the support block 17.
2) The sandwiching block 18 is moved so that the end of the stranded wire 5 is sandwiched between the horn 16.
3) The horn 16 of the ultrasonic bonding apparatus descends, pressurizes the stranded wire 5 on the support block 17, and applies ultrasonic vibration. As a result, the strands of the exposed end of the stranded wire 5 that has been pressed and vibrated are melted and fused together, and at the same time, the fused portion is formed into a plate shape having a certain width to form a desired single wire. Part 8 is formed. In FIG. 3, the horn 16 is drawn considerably above the support block 17 for easy understanding. However, the actual lowering start of the horn 16 is between the two support blocks 17 facing each other. Done from position.

  When this method is carried out, if the molding unevenness 19 (that is, knurled in the figure) is provided on the molding surface of the support block 17 and the horn 16, the molding irregularity 19 is transferred to the single wire forming portion 8 to form a single wire. On the surface of the portion 8, minute irregularities 13 (see FIGS. 1 and 2) that increase the bonding strength with the resin holder are formed.

  Since the present invention is excellent in the reliability and durability of the connection between the cable and the sensor element, it is particularly large when applied to an exemplary rotational speed sensor that is placed near the undercarriage of an automobile and exposed to harsh conditions. Although the effect can be expected, the effectiveness is exhibited even when applied to a sensor for detecting an event or phenomenon other than the rotation speed, for example, a pressure sensor with a signal cable.

(A)-(e) is a perspective view which makes it easy to understand the joining procedure of a sensor element and a signal cable. (A)-(c) is a perspective view which shows the assembly procedure of the specific example of a sensor with a signal cable. The perspective view which shows the formation method of the single wire | line part of the terminal part of a strand wire The perspective view which expands and shows the principal part of the single wire | line part formation apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sensor element 2 Terminal 3 Signal cable 4 Core wire 5 Stranded wire 6 Jacket | cover 7 Insulation coating 8 Single wire part 9 Solder 10 Resin holder 11 Main body part 11a, 11b Holding part 11c Partition wall 11d Hole 12 Resin cover 12a Arm 13 Minute unevenness 14 Mold resin 15 Bracket 16 Horn of ultrasonic bonding apparatus 17 Support block 18 Holding block 19 Concavity and convexity 20 Molding unit forming apparatus

Claims (5)

A signal cable (3) whose conductor is composed of a stranded wire (5), a sensor element (1) having a terminal (2) for connecting the signal cable, and a resin holder (10) holding the sensor element The signal cable-attached sensor is provided with a single wire forming portion (8) formed in a flat plate shape by fusion-bonding strands of the twisted wire to the twisted wire (5) of the signal cable. The part (8) is placed on a part of the resin holder (10), and further on the terminal (2), the width direction from the side surface of the terminal (2) of the single wire forming part (8) Overlap with one side allowance W at least equal to or higher than the height H of the terminal, and soldered to the single wire portion (8) and joined to the single wire portion (8) in the width direction. Covers the area along the top of the terminal and the side of the terminal (2) A fillet of solder (9) is formed, and further, the resin holder (10) is heat-sealed to a portion covering the soldering portion of the terminal (2), and the resin holder (10) and the single wire portion (8) ) Are joined to each other, and the periphery of the single wire portion is fixed with a mold resin (14). The signal cable according to claim 1 , wherein a minute unevenness (13) is formed on a surface of the single wire forming portion (8), and a surface having the minute unevenness (13) is fused to the resin holder (10). Sensor. The sensor with a signal cable according to claim 1 or 2 , wherein the sensor is a rotation speed sensor that detects a rotation speed of the rotating body. A single-wire unit formed by flattening the strand wire (5) by fusing and unifying the strands of the strand wire by applying pressure and ultrasonic vibration to the strand wire (5) of the signal cable (3) (8) is formed, and the single wire forming portion (8) is placed on a part of the resin holder (10), and the terminal (2) of the sensor element (1) is further placed on the single wire forming portion (8). ) And solder the terminal (2) to the single wire section (8) in such a manner that the protrusion W on one side in the width direction from the side surface of the terminal (2) is at least the height H of the terminal. Then, the signal holder according to any one of claims 1 to 3 , wherein the resin holder (10) is heat-sealed to a portion covering the soldered portion of the terminal (2), and the periphery thereof is solidified with a mold resin (14). Manufacture of sensor with signal cable to complete sensor with cable Method. Claims fusing single-wire portion of the resin holder (10) by dissolving contact to (8) to the single-wire portion (8) of the terminal the resin holder in the heat during soldering (2) (10) Item 5. A method for manufacturing a sensor with a signal cable according to Item 4 .

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