JP4996336B2 - Manufacturing method of temperature sensor - Google Patents

Description

The present invention relates to the production how the temperature sensor.

  Conventionally, a temperature sensor provided with a connector for electrically connecting to the outside and a temperature detection member such as a thermistor has been researched and developed.

  As such a temperature sensor, for example, in Patent Document 1, a cap containing a thermistor element is integrated by integral molding, and the other end of a lead wire having one end connected to the thermistor element is taken out from the outside. A temperature sensor is disclosed in which a collar having a knurled portion on its outer peripheral surface is press-fitted and fixed to the collar mounting hole provided in the body by utilizing the cooling shrinkage action of the integrally molded body. And according to this, it is described that the quality can be remarkably improved as a temperature sensor for automobiles used in a relatively high temperature state or a state of intense vibration.

  Further, in Patent Document 2, in a temperature detection sensor in which a connector portion and a temperature detection portion are integrated by a casing, the casing has a plurality of attachment locking portions set so that the attachment directions of the temperature detection sensor main body are different. There is disclosed a temperature detection sensor characterized by comprising: And according to this, it is described that a highly versatile temperature detection sensor can be provided.

  Further, Patent Document 3 includes a temperature sensing element, a resin case in which the temperature sensing element is insert-molded, and the thickness of the molding resin around the temperature sensing element is adjusted by a retraction amount when molding the molding die, The structure of the temperature detection sensor provided with this is disclosed. And according to this, the temperature sensing element can be sealed in the case with a small number of steps, and the thermal responsiveness of the temperature sensing element can be set variously without leaving any trace of the pin after molding. , And is described.

In Patent Document 4, a detected temperature signal is converted into an electrical signal, and a detection element having a first electrode and a second electrode can be electrically contacted with the first electrode and the second electrode on one side. A first output extraction unit having a first holding unit and a second holding unit for holding the detection element and electrically connected to the first holding unit and the second holding unit independently on the other side; A first terminal and a second terminal having a second output extraction portion, a detection element, a first holding portion and a second holding portion are inserted inside, and the first output extraction portion and the second output extraction portion are exposed to the outside. There is disclosed a temperature detection device including a resin case that is formed by insert molding a detection element, a first terminal, and a second terminal into the resin case. And it is described that according to this, the temperature detection apparatus which made the sensitivity favorable and improved the reliability of electrical connection can be provided.
Japanese Patent Laid-Open No. 3-108624 JP-A-7-27622 Japanese Patent Laid-Open No. 6-129915 JP-A-8-159881

  However, the temperature sensor according to Patent Documents 1 and 2 uses a protective cap at the time of resin molding in order to prevent the sensor element from being exposed to the outside due to molding resin pressure. Variations in responsiveness due to element misalignment occur. Further, when the protective cap is thin, the response varies due to gas accumulation in the cap.

  Further, the temperature sensors according to Patent Documents 3 and 4 are manufactured by holding the sensor element or the lead wire with a mold, but in this case, the structure of the mold becomes complicated and causes an increase in cost. . Further, since the operation time of the slide core is added, there is a problem that the molding time becomes long.

The present invention has been made in view of the above points, and the object of the present invention is to suppress the deformation of the lead wire, the displacement of the sensor element and the occurrence of gas accumulation, respectively, and the thermal responsiveness of the temperature sensor. variations can be satisfactorily suppressed, and to provide a manufacturing how short the temperature sensor of molding tact.

The temperature sensor manufacturing method according to the present invention includes a step of preparing a sensor element and a temperature detection member having a pair of lead wires electrically connected to the sensor element, and an external connection terminal on each of the pair of lead wires. A step of connecting, a step of preparing a protective cap formed in a bottomed cylindrical shape and provided with a notch in the wall, and a temperature detecting member for protecting the temperature detecting member so as to face the bottom surface of the protective cap A first molding die in which a recess for fitting the tip of the protective cap and fixing the tip is formed, an engagement portion for engaging the opening end of the protection cap and fixing the opening end, is fitted an external connection terminal is constituted by the external connection second mold pin insertion holes are formed for fixing the terminal has a cavity region for accommodating the temperature sensing member and the protective cap A step of preparing the mold, a step of storing and holding the protective cap and the temperature detection member accommodated in the protective cap in the cavity region of the mold, and injecting and injecting resin into the cavity region of the mold And a step of forming a connector by molding.

  In the temperature sensor manufacturing method according to the present invention, the protective cap and the connector may be formed of the same resin material.

  Furthermore, the manufacturing method of the temperature sensor according to the present invention may include a plurality of cutouts in the protective cap.

  In the method for manufacturing a temperature sensor according to the present invention, the cutouts of the protective cap may be formed at positions facing each other on the wall portion of the protective cap.

  Further, in the method of manufacturing the temperature sensor according to the present invention, in the step of accommodating the temperature detection member inside the protective cap, the protective cap is arranged so that the notched region corresponds to the pair of lead wires. Also good.

  In the temperature sensor manufacturing method according to the present invention, the temperature detecting member may be accommodated in the protective cap, and the protective cap may be disposed so that the inner surface thereof is in contact with the sensor element and the pair of lead wires, respectively. Good.

In the temperature sensor manufacturing method according to the present invention, the resin may be injected into the cavity region of the mold from the notch non-forming region side of the protective cap in the step of forming the connector by performing injection molding.

Furthermore, the manufacturing method of the temperature sensor according to the present invention includes a resin on a wall portion of the inner surface of the second mold and corresponding to a not-not-formed region of the protective cap housed in the cavity region of the mold. An injection port is formed. In the step of forming the connector by injecting resin into the cavity region of the mold and performing injection molding, the resin may be injected from the resin injection port.

According to the present invention, the deformation of the lead wire, the displacement of the sensor element and the occurrence of gas accumulation can be suppressed, the variation in the thermal responsiveness of the temperature sensor can be satisfactorily suppressed, and the molding tact temperature it is possible to provide a manufacturing how the sensor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

(Embodiment)
(Configuration of temperature sensor)
1 is a perspective view showing a temperature sensor 10 of the present embodiment, FIG. 2 is a cross-sectional view taken along the line II of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line II-II of FIG. is there.

  The temperature sensor 10 includes a temperature detection member 11, a protective cap 12 and a connector 13.

  The temperature detection member 11 is, for example, a thermistor whose resistance value decreases as the temperature rises. The sensor element 14 detects the temperature of water, oil, air or the like, and a pair of sensors electrically connected to the sensor element 14. An external connection terminal 16 electrically connected to the lead wire 15 and the pair of lead wires 15 is provided.

  The sensor element 14 is made of, for example, manganese, nickel, cobalt, or the like, and is a polycrystalline body in which crystal grains having a so-called spinel structure are collected. The sensor element 14 is coated with an epoxy resin, a glass material, or the like in order to relieve stress received from a resin (described later) of the connector 13 that covers the sensor element 14.

  The lead wire 15 is formed by covering a conductive wire made of, for example, Cu or CuNi with Teflon (registered trademark). One end of the lead wire 15 is electrically connected to the sensor element 14, and the other end is electrically connected to the external connection terminal 16. The external connection terminal 16 is connected to an end portion of the lead wire 15 so as to be different from the lead wire 15.

  FIG. 4 is a plan view of the protective cap 12 according to the present embodiment. FIG. 5 is a side view of the protective cap 12 according to the present embodiment. The protective cap 12 is formed in a cylindrical shape with a bottom and is provided with a notch 21 in the wall portion 19 and accommodates the temperature detection member 11 therein so that the sensor element 14 faces the bottom surface 22. The opening end 17 of the protective cap 12 serves as a mark for easily recognizing which side the external connection terminal 16 connected to be different from the lead wire 15 of the temperature detection member 11 is accommodated. , Leaving only a part, the other is formed wide. Further, the wide opening end 17 also has a role of satisfactorily engaging with a molding die 20 described later.

  Two cutouts 21 are formed in the wall 19 of the protective cap 12. The two notches 21 are formed at positions facing each other on the wall portion 19 of the protective cap 12. For this reason, it can suppress more favorably that gas accumulates in the protective cap 12 at the time of the injection molding of the connector 13 by resin injection mentioned later.

  In addition, the notch 21 may be formed not only in the wall part 19 of the protective cap 12 but more than two, and may be formed only one.

  The protective cap 12 is disposed so that the region of the wall portion 19 where the notch 21 is not formed (the notch-unformed region 25) corresponds to the pair of lead wires 15 of the temperature detection member 11. More specifically, the notch 21 of the protective cap 12 is disposed so as to face a region where the lead wire 15 is not provided, and the not-not-formed region 25 of the protective cap 12 is disposed so as to face the pair of lead wires 15. Yes. For this reason, the pressure of the injected resin can be prevented from being directly applied to the lead wire 15 during the injection molding of the connector 13 by resin injection, which will be described later, in the not-cut region 25 of the protective cap 12. Therefore, deformation of the lead wire 15 due to the injection resin pressure can be satisfactorily suppressed.

  Further, the protective cap 12 is disposed such that the inner surface thereof is in contact with the sensor element 14 and the pair of lead wires 15. For this reason, the protective cap 12 can be formed to a minimum necessary size. Therefore, the temperature sensor 10 can be formed compactly. Furthermore, since the protective cap 12 is in contact with the lead wire 15, it is possible to better prevent the pressure of the injected resin from being directly applied to the lead wire 15.

  The connector 13 is provided so as to cover the temperature detection member 11 and the protective cap 12 that houses the temperature detection member 11 therein. The connector 13 forms the outer shape of the temperature sensor 10 by covering the temperature detection member 11 and the protective cap 12, and is integrally formed with the resin filled in the gap between the temperature detection member 11 and the protective cap 12. The connector 13 is made of the same resin material as that of the protective cap 12. For this reason, the bondability between the connector 13 and the protective cap 12 accommodated in the connector 13 is improved.

  Any of these resin materials may be used. For example, polybutyl terephthalate (PBT), polyphenylene sulfide (PPS), polyacetal (POM), or the like can be preferably used.

  The connector 13 includes a temperature detection unit 26 provided on the temperature measurement target side and a connection unit 27 provided on the connection target side of the external connection terminal 16 that are integrally formed.

  The temperature detection part 26 of the connector 13 accommodates the temperature detection member 11 and the protective cap 12 that accommodates the temperature detection member 11 therein. A predetermined portion of the sensor element 14 of the temperature detection member 11 protrudes from the tip of the temperature detection unit 26 of the connector 13. On the outer surface of the temperature detector 26 of the connector 13, a slide fixing protrusion 28 is integrally formed.

  The connection part 27 of the connector 13 is formed in a substantially cylindrical shape. In the connection part 27 of the connector 13, the external connection terminal 16 connected to the lead wire 15 of the temperature detection member 11 protruding from the temperature detection part 26 is exposed.

  A cable terminal is inserted into the connection portion 27 of the connector 13 and is electrically connected to the external connection terminal 16. The temperature of the object to be measured is calculated based on the change in the resistance value of the sensor element 14 with an electronic control device or the like electrically connected to the cable terminal.

  Further, a slide fixing protrusion 28 is integrally formed on the temperature detection portion 26 of the connector 13.

  The temperature sensor 10 can be detachably and stably attached without using a special clip or the like by sliding the above-described protrusion 28 into, for example, a notch in an attachment location such as an automobile body. be able to.

(Method for manufacturing temperature sensor 10)
Next, a method for manufacturing the temperature sensor 10 according to the present embodiment will be described.

  First, a temperature detection member 11 having a sensor element 14 and a pair of lead wires 15 electrically connected to the sensor element 14 is prepared.

  Next, the external connection terminals 16 are electrically connected to the pair of lead wires 15 by soldering or the like.

  Next, the protective cap 12 is prepared, and the temperature detection member 11 is accommodated in the protective cap 12 so that the sensor element 14 faces the bottom surface of the protective cap 12. At this time, the protective cap 12 is disposed so that the notch-unformed region 25 corresponds to the pair of lead wires 15 and the inner surface thereof is in contact with the sensor element 14 and the pair of lead wires 15, respectively.

  Next, a mold 20 having a cavity region (33 and 35) for accommodating the temperature detection member 11 and the protective cap 12 is prepared. As shown in FIG. 6, the molding die 20 is used in combination with each other, a first molding die 31 that molds the temperature detection unit 26 of the temperature sensor 10, and a second molding that molds the connection portion 27 of the temperature sensor 10. It consists of a mold 32.

  The first mold 31 is formed with a cavity region 33 that constitutes a part of the outer shape of the connector 13 and a recess 34 for fitting and fixing the tip of the protective cap 12.

  The second molding die 32 is fitted with a cavity region 35 that constitutes a part of the outer shape of the connector 13, an engaging portion 36 that is engaged with and fixed to the opening end 17 of the protective cap 12, and the external connection terminal 16. A terminal insertion hole 37 is formed for inserting and fixing.

  In addition, a resin injection port is formed at a portion corresponding to the notch non-forming region 25 of the protective cap 12 to be accommodated on the inner wall of the second mold 32. For this reason, when the connector 13 is injection-molded by resin injection, it is possible to prevent the pressure of the injected resin from being directly applied to the lead wire 15 by the notched region 25 of the protective cap 12. Therefore, deformation of the lead wire 15 due to the injection resin pressure can be satisfactorily suppressed.

  By combining the first and second molding dies 31 and 32 having such a configuration, the protective cap 12 and the temperature detection member 11 accommodated inside the protective cap 12 are placed in the cavity region (33 and 35) of the molding die 20. Hold and hold. In this way, the molding cap 20 presses the protective cap 12 of the temperature detection member 11 to protect the lead wire 15 and the sensor element 14 from the resin pressure at the time of injection molding. Deviation can be suppressed. Therefore, variation in the thermal response of the temperature sensor 10 can be suppressed satisfactorily. Further, it is not necessary to slow down the molding speed in order to suppress deformation, disconnection, breakage, etc. of the sensor element 14, and the temperature sensor 10 can be manufactured at low cost.

  Next, injection molding is performed by injecting resin into the cavity region (33 and 35) of the mold 20 from the resin injection port. The injected resin spreads densely in the cavity regions (33 and 35), forms the outer shape of the mold 20, and is filled in the gap between the protective cap 12 and the temperature detecting member 11. At this time, since the notch 21 is provided in the wall portion 19 of the protective cap 12, it is possible to satisfactorily suppress gas during molding from being accumulated in the protective cap 12.

  In addition, an injection mark is formed at a portion corresponding to the resin injection port on the outer surface of the connector 13.

  Thus, the connector 13 is completed.

(Function and effect)
Next, the function and effect will be described.

  The manufacturing method of the temperature sensor 10 according to the embodiment of the present invention includes a step of preparing a temperature detection member 11 having a sensor element 14 and a pair of lead wires 15 electrically connected to the sensor element 14, and a bottomed cylinder A step of preparing a protective cap 12 formed in the shape of a wall and provided with a notch 21 in the wall portion 19, and the temperature detecting member 11 inside the protective cap 12 so that the sensor element 14 faces the bottom surface of the protective cap 12. A step of preparing the mold 20 having a cavity region (33 and 35) for accommodating the temperature detecting member 11 and the protective cap 12, and a temperature detection accommodated in the protective cap 12 and the protective cap 12. Housing and holding the member 11 in the cavity region (33 and 35) of the mold 20, and the cavity region of the mold 20; Forming a connector 13 by performing injection molding resin injected into the (33 and 35), characterized by comprising a.

  According to such a configuration, the deformation of the lead wire 15 or the sensor is detected in order to protect the lead wire 15 and the sensor element 14 from the resin pressure at the time of injection molding by pressing the protective cap 12 of the temperature detecting member 11 with the molding die 20. The positional deviation of the element 14 can be suppressed. Therefore, variation in the thermal response of the temperature sensor 10 can be suppressed satisfactorily. Further, it is not necessary to slow down the molding speed in order to suppress deformation, disconnection, breakage, etc. of the sensor element 14, and the temperature sensor 10 can be manufactured at low cost. Furthermore, since the notch 21 is provided in the wall part 19 of the protective cap 12, it can suppress favorably that the gas at the time of shaping | molding accumulates in the protective cap 12. FIG.

As described above, the present invention relates to the production how the temperature sensor.

It is a perspective view which shows the temperature sensor 10 of embodiment of this invention. It is sectional drawing in the II line | wire of FIG. It is sectional drawing in the II-II line of FIG. It is a top view of protective cap 12 concerning an embodiment of the present invention. It is a side view of the protective cap 12 which concerns on embodiment of this invention. It is sectional drawing of the shaping | molding die 20 which accommodates and hold | maintains the temperature sensor 10 which concerns on embodiment of this invention.

10 Temperature sensor
11 Temperature detection member
12 Protective cap
13 Connector
14 Sensor elements
15 Lead wire
16 External connection terminals
17 Open end
19 Wall
20 Mold
22 Bottom
25 Not-cut region
26 Temperature detector
27 connections
28 protrusions
31 First mold
32 Second mold
33, 35 cavity area
34 recess
36 engaging part
37 Terminal insertion hole

Claims (8)

Providing a temperature sensing member having a sensor element and a pair of lead wires electrically connected to the sensor element;
Connecting an external connection terminal to each of the pair of lead wires;
Preparing a protective cap formed in a bottomed cylindrical shape and provided with a notch in the wall;
Accommodating the temperature detection member inside the protective cap so that the sensor element faces the bottom surface of the protective cap;
A first mold having a recess for fitting the tip of the protective cap to fix the tip, an engaging portion for engaging the opening end of the protective cap and fixing the opening end, and the external connection terminal Preparing a mold having a cavity region for accommodating the temperature detecting member and the protective cap, and a second mold having a terminal insertion hole for fixing the external connection terminal .
Storing and holding the protective cap and the temperature detection member housed inside the protective cap in the cavity region of the mold; and
Forming a connector by injecting resin into the cavity region of the mold and performing injection molding;
A method for manufacturing a temperature sensor. In the manufacturing method of the temperature sensor according to claim 1,
A method of manufacturing a temperature sensor, wherein the protective cap and the connector are formed of the same resin material. In the manufacturing method of the temperature sensor according to claim 1,
A method for manufacturing a temperature sensor, wherein a plurality of notches of the protective cap are formed. In the manufacturing method of the temperature sensor according to claim 3,
The method for manufacturing a temperature sensor, wherein the notches of the protective cap are formed at positions facing each other on the wall of the protective cap. In the manufacturing method of the temperature sensor according to claim 1,
A method of manufacturing a temperature sensor, wherein the step of accommodating the temperature detecting member in the protective cap includes arranging the protective cap so that a not-not-formed region corresponds to the pair of lead wires. In the manufacturing method of the temperature sensor according to claim 1,
A method of manufacturing a temperature sensor, wherein the step of accommodating the temperature detecting member in the protective cap includes arranging the protective cap so that the inner surface thereof is in contact with the sensor element and the pair of lead wires, respectively. In the manufacturing method of the temperature sensor according to claim 1,
A method for manufacturing a temperature sensor, comprising: injecting the resin from a notch non-formation region side of the protective cap into a cavity region of the mold in the step of forming a connector by performing the injection molding. In the manufacturing method of the temperature sensor according to claim 1,
A resin injection port is formed in a portion of the inner wall of the second mold that corresponds to a not-not-formed region of the protective cap housed in the cavity region of the mold,
A method of manufacturing a temperature sensor, wherein a resin is injected from the resin injection port in a step of forming a connector by injecting resin into a cavity region of the mold and performing injection molding.

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