JP3711951B2 - Sensor structure and sensor manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sensor structure and a sensor manufacturing method, and is particularly suitable when the connector pin connected to the detection portion of the sensor is thin.
[0002]
[Prior art]
In recent years, the demand for miniaturization of electrical components mounted on automobiles has become increasingly severe. Various sensors are connected to the electrical component, but in order to reduce the size of the electrical component, it is required to adopt a connector pin having a narrow width for the connection.
[0003]
In the conventional sensor structure, the connector body is insert-molded to form the sensor body. However, since a wide (for example, 2.3 mm) connector pin is used, the tip (terminal part) of this connector pin is made of gold. By fitting in a hole formed in the slide core inside the mold, the mounting property to the slide core and the holding force at the time of molding were sufficiently obtained.
[0004]
[Problems to be solved by the invention]
However, when a connector pin having a narrow width (for example, 0.64 mm) is used in order to meet the above-described demand for miniaturization, it is difficult to mount the slide pin inside the mold and the molding pin is held during molding. It is easy to run out of power. That is, since the width of the hole formed in the slide core is also narrowed, it becomes difficult to insert the slide pin, and the slide pin is easily deformed due to resistance at the time of mounting, so that the connector pin mounting property is deteriorated. Furthermore, even if it can be mounted, it is likely to be deformed or displaced due to the pressure received from the molding resin during the insert molding of this connector pin.
[0005]
The present invention has been made in view of the above points, and even when a thin connector pin is employed, a sensor structure and a sensor manufacture that do not cause deformation of the connector pin or the like when the sensor is manufactured. It aims to provide a method.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the sensor structure according to claim 1 comprises:
A detection unit, a plurality of connector pins connected to the detection unit, and a holding unit that holds the plurality of connector pins together and has a protrusion on an end surface that exposes an end serving as a contact point of the connector pin to the outside A structure consisting of
And a resin molded portion formed around the structure in the axial direction of the connector pin.
[0007]
According to the sensor structure, the resin molded portion is formed around the structure including the detection portion, the plurality of connector pins, and the holding portion. Here, the holding portion is formed with a protrusion on the end surface that exposes the end portion of the connector pin to the outside. For this reason, at the time of formation of the resin molding part, the structure can be held in the mold by fitting the protrusion of the holding part into the hole formed in the mold instead of the end of the connector pin. Accordingly, it is possible to prevent deterioration of the mountability of the insert molded structure to the mold, and to prevent the connector pins from being deformed during mounting or insert molding.
[0008]
In addition, since the structure including the holding part is insert-molded inside the resin molding part, the structure can be used in common even if the outer shape of the sensor is different, reducing the manufacturing cost of the sensor. Is possible.
[0009]
In the sensor structure according to claim 2, the holding portion includes a primary resin molding portion in which a plurality of connector pins are insert-molded, and the primary resin molding portion is formed at a position where the primary resin molding portion is insert-molded by the resin molding portion. Sometimes, a plurality of holding pins for holding a plurality of connector pins at predetermined positions in the mold are formed.
[0010]
Thus, by forming the sensor by two-stage resin molding, most of the primary resin molded portion is sealed by the resin molded portion formed around the structure and is not exposed to the outside. Therefore, the primary resin molding portion in the portion inserted (sealed) in the resin molding portion formed around the structure does not need to ensure waterproofness and airtightness. Therefore, as described above, the connector pin is formed into the primary resin by forming the hole of the holding pin that holds the plurality of connector pins in a predetermined position in the mold in the primary resin molding portion that is insert-molded by the resin molding portion. It is possible to reliably prevent deformation and displacement of the connector pin when insert molding is performed on the molding portion.
[0011]
As described in claim 3, it is preferable that the hole of the holding pin of the primary resin molding part is filled with the molding resin of the resin molding part. When molding the secondary resin to form the resin molded part, if the molded resin flows and fills the hole in the primary resin molded part, the primary resin molded part and the resin molded part formed around it Can be firmly bonded.
[0012]
The method for manufacturing a sensor according to claims 4, 6, and 7 is for obtaining the sensor structure according to claims 1, 2, and 3, respectively, and the operation and effect thereof correspond to claims 1 and 2. , 3 is similar to that of the sensor structure, and the description thereof is omitted.
[0013]
The sensor manufacturing method according to claim 5, wherein an end of the structure opposite to a side where the protrusion of the holding portion is formed is also fitted into the mold, so that the structure is in the mold. It is characterized by being fixed to. Thus, since the holding power of the structure is improved by fitting both ends of the structure to the mold, it is possible to prevent misalignment or the like when the structure is insert-molded into the resin-molded part. .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
FIG. 1A is a cross-sectional view showing the structure of a rotation detection sensor when the sensor structure according to the present embodiment is applied to a rotation detection sensor for detecting the rotation speed of an internal combustion engine, and FIG. It is a partial cross section figure which shows the structure of the structure insert-molded by the secondary resin molding part, and the cross section of the secondary resin molding part formed in the circumference | surroundings of the structure.
[0016]
In FIGS. 1A and 1B, reference numeral 8 denotes a detection unit, which has a detection element that outputs a signal corresponding to a change in magnetic field, such as a magnetoresistive element, and is sealed with resin. It has stopped. A hollow magnet 5 is disposed around the detection unit 8. For this reason, when the rotor (not shown) attached to the rotating shaft of the internal combustion engine and having gear teeth on the outer peripheral surface rotates, the direction of the bias magnetic field from the magnet 5 toward the gear teeth changes. The resistance value of the magnetoresistive element changes according to the direction of the magnetic field, and the rotational speed of the internal combustion engine can be detected by taking out the change in resistance value as, for example, a voltage signal. The detection element provided in the detection unit 8 is not limited to the magnetoresistive element, and a Hall element may be used.
[0017]
Furthermore, a cup-shaped cap 6 is provided so as to cover the magnet 5. The cap 6 is made of resin, and ring-shaped protrusions are formed at a plurality of locations on the outer periphery thereof. Therefore, when the secondary molding resin is injected into the mold in order to form the secondary resin molding portion 10 to be described later, the protrusion of the cap 6 is melted by the secondary molding resin, and the secondary resin molding portion 10 And the cap 6 are welded. For this reason, the magnet 5 and the detection part 8 are accommodated in the cap 6 and the secondary resin molding part 10 in an airtight state. The rotation detection sensor according to the present embodiment may be used in a state where the end portion on the side where the detection unit 8 is disposed is immersed in oil, and thus the airtight structure described above so that the oil does not enter the inside. Is adopted.
[0018]
A lead terminal 4 connected to the detection element is provided inside the detection unit 8, and an end portion of the lead terminal 4 protrudes from the sealing resin of the detection unit 8 to the outside. In the present embodiment, three end portions of the lead terminal 4 are provided. Three connector pins 7 are also provided corresponding to the lead terminals 4, and each lead terminal 4 is joined to one end of the connector pin 7 by caulking welding. 9 shows the caulking weld. The other end of the connector pin 7 protrudes into the connector housing 13 formed as a part of the secondary resin molding part 10. Therefore, the other end portion of the protruding connector pin 7 functions as a connection terminal and comes into contact with a connection terminal of a female connector (not shown).
[0019]
In this embodiment, for example, thin connector pins 7 having a width of 0.64 mm are employed, and these three thin connector pins 7 are insert-molded and fixed to the primary resin molding portion 1.
[0020]
Here, using FIGS. 2A to 2C, a structure that is insert-molded into a secondary resin molding portion 10 including the primary resin molding portion 1, the connector pin 7, the detection portion 8, the magnet 5, and the cap 6. The manufacturing process of the body will be described.
[0021]
First, in a state where the three connector pins 7 are arranged at predetermined positions on the mold dividing surface of the fixed mold and the movable mold, the primary molding resin is injected into the space around the connector pins 7 in the mold. By doing so, the three connector pins 7 are insert-molded in the primary resin molding part 1.
[0022]
At this time, if the end of the connector pin 7 is fitted with the hole formed in the slide core in the mold and held in a predetermined position during insert molding as in the conventional case, the connector pin 7 is thin. The connector pin 7 may be deformed or displaced due to the pressure from the injected primary molding resin.
[0023]
For this reason, in this embodiment, instead of holding the connector pin 7 by inserting the end portion of the connector pin 7 into the hole of the slide core, the holding pin is formed at a plurality of locations of the fixed type and the movable type, The connector pins 7 are held in the mold by sandwiching the connector pins 7 with the holding pins. Thereby, since the holding force of the connector pin 7 improves, the deformation | transformation and position shift of the connector pin 7 can be prevented.
[0024]
Next, the end portions of the three connector pins 7 fixed by the primary resin molding portion 1 and the three lead terminals 4 of the detection portion 8 are respectively caulked and welded. Specifically, a hole into which the lead terminal 4 is inserted is formed at the end of the connector pin 7, and the end of the connector pin 7 is bent with the lead terminal 4 inserted into the hole. Close. Thereafter, the caulked portion 9 is formed by welding the further caulked portion.
[0025]
Finally, as shown in FIG. 2C, the hollow magnet 5 and the cap 6 are attached to the detection unit 8, and the structure to be inserted into the secondary resin molding unit 10 is completed.
[0026]
However, in the production of the structure described above, when the primary resin molding part 1 is formed, if the primary molding resin is injection-molded with the connector pin 7 held between the holding pins, the primary resin molding part 1 holds it. A pin hole 3 is formed.
[0027]
Therefore, in the present embodiment, a structure including the primary resin molding portion 1, the connector pin 7, the detection portion 8, the magnet 5, and the cap 6 is insert-molded with a secondary molding resin.
As a result, even if the retaining pin hole 3 is formed in the primary resin molding part 1, the hole 3 is blocked by the secondary resin molding part 10, so that oil and moisture enter the rotation detection sensor. Can be prevented. Note that when the molten secondary molding resin is caused to flow around the primary resin molding portion 1 in which the through hole 3 is formed, the secondary molding resin is filled in the through hole 3. As a result, the through hole 3 of the primary resin molding part 1 produces a lock hole effect, so that the primary resin molding part 1 and the secondary resin molding part 10 can be firmly bonded.
[0028]
When the structure is insert-molded with a secondary molding resin, the structure needs to be held in a mold. At this time, if the position of the structure is held by the end of the connector pin 7, problems such as deformation of the connector pin 7 occur. For this reason, in this embodiment, the end of the connector pin 7 is the end surface of the primary resin molding portion 1 on the side protruding into the connector housing 13, and the protrusion 2 is formed at a position through which the three connector pins 7 pass. are doing. And this structure is hold | maintained by making this protrusion 2 fit in the fitting hole formed in the metal mold | die. Specifically, the structure is disposed on the parting surfaces of the fixed mold and the movable mold. A hole that fits with the protrusion 2 of the primary resin molding portion 1 is formed in the slide core that slides on the mold dividing surface while accommodating the connector pin 7. When the movable mold and the fixed mold are clamped, the protrusion 2 of the primary resin molded portion 1 is fitted into the fitting hole in the cavity formed by the movable mold and the fixed mold, so that the structure is predetermined. Held in position.
[0029]
Thus, the holding force can be improved by holding the structure to be inserted by using the protruding portion 2 that is thick and wide at the time of secondary resin molding. As shown in FIGS. 1A and 1B, if the bottom of the cap 6 forming the end of the structure is not covered by the secondary resin molding portion 10, the portion not covered by the cap 6 is not covered. It can be clamped and fixed by a movable mold and a fixed mold. Thereby, the retention strength of the structure can be further improved.
[0030]
The secondary resin molding portion 10 is formed around the structure in the axial direction of the connector pin 7. In addition to the connector housing 13 described above, the secondary resin molding portion 10 has a flange 12 for attaching the rotation detection sensor to the vehicle body. A ring-shaped metal fitting 14 is insert-molded on the inner peripheral surface of the hole through which the bolt of the flange 12 is inserted.
[0031]
Since the rotation detection sensor of the present embodiment is formed by two-stage resin molding as described above, the secondary resin molded portion 10 formed around the primary resin molded portion 1 needs to be thick. There is no. For this reason, the dimensional stability of the secondary resin molding part 10 can be improved. In particular, when this rotation detection sensor is used to detect the rotation speed of the internal combustion engine, a part of the sensor on the detection unit 8 side may be inserted into the internal combustion engine. In this case, it is necessary to attach a seal member such as an O-ring to the concave portion 11 of the secondary resin molded portion 10 and seal the opening to the internal combustion engine with this seal member. For this reason, high precision is required especially for the dimension of the recess 11 in which the seal member is mounted. Even in such a case, in the rotation detection sensor according to the present embodiment, the outer dimensions of the secondary resin molded portion 10 can be adjusted with high accuracy.
[0032]
Furthermore, since the rotation detection sensor according to the present embodiment is formed by two-stage resin molding, the structure including the primary resin molding portion 1 is commonly used even when the outer shape of the rotation detection sensor is slightly different. This can reduce the manufacturing cost of the sensor. For example, as shown in FIGS. 3A and 3B, the position of the flange 12 for attaching the rotation detection sensor to the vehicle body or the internal combustion engine needs to be changed depending on the type of the vehicle or the internal combustion engine. Even in such a case, only the mold for forming the secondary resin molding portion 10 needs to be changed correspondingly, and the inserted structure can be used in common.
[0033]
In the above-described embodiment, in the structure inserted into the secondary resin molding portion 10, the connector pin 7 is insert-molded and fixed by the primary resin molding portion, but the fixing does not need to be performed by the insert molding portion. For example, a concave portion and a convex portion that are fitted to each other are provided on the contact surface between the resin portions divided into two, and the concave portion and the convex portion are arranged with the connector pin 7 disposed between the two divided resin portions. The connector pins 7 may be fixed by fitting the portions. The resin block is provided with a through-hole into which the connector pin 7 is press-fitted, and the connector pin 7 is press-fitted into the through-hole so that the end of the connector pin 7 is exposed from both ends of the through-hole. 7 may be fixed.
[0034]
Moreover, when automating the manufacture of the structure, for example, the method shown in FIGS. 5A and 5B can be employed. That is, first, as shown in FIG. 5 (a), a metal (for example, brass) plate having a predetermined width is sent to the press punching machine in the longitudinal direction so that the direction perpendicular to the feeding direction is obtained. A plurality of connector pins 7 are continuously punched and formed. In this case, the outer peripheral edge portion of the plate is left as an outer frame 20 for holding the plurality of punched connector pins 7. In the outer frame 20, a positioning hole 21 for positioning the connector pin 7 is punched and formed simultaneously with the connector pin 7 in an injection molding machine including a mold later.
[0035]
Next, the connector pin 7 held by the outer frame 20 is sent to the injection molding machine and is positioned at a predetermined position by the positioning hole 21 formed in the outer frame 20. In this state, by injecting the molding resin into the mold, a plurality of connector pins 7 can be insert-molded in the primary resin molding portion 1 as shown in FIG. Thereafter, the plurality of connector pins 7 fixed to the primary resin molding part 1 are separated from the outer frame 20, and are connected to the detection part 8, the magnet 5, and the cap 6 and are assembled.
[0036]
By adopting such a method, when the connector pin 7 is insert-molded, the connector pin 7 is held by the outer frame 20, so that the positional accuracy of the connector pin can be improved and the manufacture thereof is automated. Becomes easier.
[Brief description of the drawings]
1A is a cross-sectional view showing a structure of a rotation detection sensor according to an embodiment of the present invention, and FIG. 1B is a structure of a structure that is insert-molded in a secondary resin molded portion, and the structure thereof; It is a partial cross section figure which shows the cross section of the secondary resin molding part formed in the circumference | surroundings of a body.
FIGS. 2A and 2B are a plan view and a cross-sectional view showing the structure of the primary resin molding part 1, the connector pin 7 and the detection part 8, and FIG. 2C is the primary resin molding part 1 and the connector pin; 7 is an explanatory diagram for explaining a process of assembling a structure including the detection unit 8, the magnet 5, and the cap 6. FIG.
FIGS. 3A and 3B are side views of the sensor showing variations in the mounting position of the flange. FIGS.
FIGS. 4A and 4B are explanatory views for explaining a manufacturing process of the connector pin 7 and the primary resin molded portion 1. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Primary resin molding 2 Protrusion 3 of primary resin molding 5 Hole 5 Magnet 6 Cap 7 Connector pin 8 Detection part 10 Secondary resin molding part

Claims (7)

Holding the detection unit, the plurality of connector pins connected to the detection unit, and holding the plurality of connector pins together, and having a protrusion on the end surface that exposes the end serving as the contact point of the connector pin to the outside A structure composed of parts,
A sensor structure comprising: a resin molding portion formed around the structure in the axial direction of the connector pin. The holding portion includes a primary resin molding portion in which a plurality of connector pins are insert-molded, and the plurality of connector pins are formed when the primary resin molding portion is formed at a position where the primary resin molding portion is insert-molded into the resin molding portion. The sensor structure according to claim 1, wherein a hole for holding a pin is formed in the mold to hold the pin in a predetermined position. The sensor structure according to claim 2, wherein a hole in the holding pin of the primary resin molding portion is filled with a molding resin of the resin molding portion. A forming step of holding a plurality of connector pins together and forming a holding portion having a protrusion on an end surface that exposes an end portion that becomes a contact point of the connector pin, and
A connecting step of connecting the plurality of connector pins to a plurality of lead terminals of the detection unit, respectively;
A fixing step of fixing the structure in the mold by disposing the structure including the detection unit, the connector pin, and the holding unit in the mold, and fitting the protrusion of the holding unit into the mold; ,
Forming a resin molding portion around the structure in the axial direction of the connector pin by injecting molding resin into a space around the structure in the mold. A method for manufacturing a sensor. 5. The sensor manufacturing method according to claim 4, wherein, in the fixing step, an end portion of the structure opposite to a side where the protrusion of the holding portion is formed is also fitted into a mold. The holding portion is composed of a primary resin molding portion in which a plurality of connector pins are insert-molded. At the time of forming the primary resin molding portion, the plurality of connector pins are held at predetermined positions in a mold by the holding pins, and the primary 6. The method of manufacturing a sensor according to claim 4, wherein after the resin molded portion is formed, the holding pin is pulled out from the primary resin molded portion. The method of manufacturing a sensor according to claim 6, wherein, in the forming step, a molding resin of the resin molding part is filled in a hole of the holding pin of the primary resin molding part.

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