JPH09133696A - Enclosed rotation sensor device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an enclosed rotation sensor device which can be stably maintained in an enclosed state for a long period and is formed by integrally molding a resin. SOLUTION: In an enclosed sensor device 1, a sensor assembly 10 constituted by housing a magnetic core member 5 and a permanent magnet 4 in the hollow section of a bobbin 2 wound with a coil 3 is sealed with a jacket section 7 made of a molded resin. The bobbin 2 is integrally formed so that the front end part 21A of the hollow section 21 can be closed in a bag-like state and the magnet 4 is positioned to the foremost part 21 of the section 21. Then a jacket section 8 for leader lines is formed without using any grommet by coating the leading-out end sections of covered wires 61 and 62 with a polyamide resin and closely adhered to the coatings 61B and 62B of the wires 61 and 62 while elasticity is given to the coatings 61B and 62B and the jacket section 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically-sealed rotation sensor device for use in detecting the rotational speed of various rotating bodies and a method for manufacturing the same.

[0002]

2. Description of the Related Art For example, a rotation sensor used under a bad environment such as a case of detecting a rotation speed of a vehicle wheel is required to have high airtightness.
For this reason, as disclosed in, for example, Japanese Patent Laid-Open No. 4-132964, the magnetic pole is placed around the magnetic pole in order to detect the amount of change in magnetic flux in the magnetic pole and the magnetic pole that is in contact with the magnet. In an electromagnetic induction type rotation sensor including a coil, an airtight type structure is known in which the periphery of the sensor except for the tip of the magnetic pole piece is collectively covered with a resin mold member.

[0003]

However, in this conventional airtight rotation sensor device, since the tip of the core is exposed, the difference in the expansion coefficient between the metal and the resin covering the core and the deterioration of the resin prevent both of them. However, there is a problem in that a gap is created on the boundary surface where the and the two are in close contact with each other, which causes leakage of security. In order to solve this problem, Japanese Patent Laid-Open No. 6-109482 proposes a configuration in which the tip of the core is covered with a cap made of urethane. However, since the number of parts is increased, the cost is increased and the cap is Since the material of the resin is different from the material of the molding resin, there is a problem that the advantage of cost reduction, which is a feature of resin-integrated molding, cannot be fully utilized.

Further, in this type of sensor device, the problem of ensuring the airtightness and watertightness of the lead wire lead portion is also important. Therefore, the method of filling the lead wire lead portion with an epoxy potting agent has been conventionally used. Has been adopted. However, this prior art is for drawing out the lead wire from the metal housing, and in the case of a rotation sensor formed by resin integral molding, a method using an epoxy-based potting agent has not been adopted to achieve cost reduction. As a technique for ensuring the hermeticity of the lead wire lead portion in the rotation sensor by resin integral molding, as disclosed in, for example, Japanese Patent Laid-Open No. 4-72575, an internal protective member is formed on the outer coating of the output wire. Such a configuration is known. However, since this is basically a material that does not mix with the molding resin, the airtightness and watertightness are maintained only by the adhesive force, so the airtightness is weak and the airtightness is improved over time. It had a tendency to gradually deteriorate, and there was a problem in its durability.

Therefore, an object of the present invention is to provide a sealed type rotation sensor device by resin integral molding and a method for manufacturing the same which can solve the above-mentioned problems in the prior art.

An object of the present invention is to provide a hermetically sealed rotation sensor device by resin molding which can ensure its hermeticity stably for a long period of time without increasing the number of parts and a manufacturing method thereof. .

An object of the present invention is to provide a hermetically-sealed rotation sensor device by resin molding which can surely seal the tip of a core constituting a rotation sensor without causing a problem of output reduction, and the same. It is to provide a manufacturing method.

An object of the present invention is to provide a hermetically sealed rotation sensor device by resin-integral molding, which is capable of melting a bobbin that covers the tip of the core and a resin for integral molding, and can realize higher hermeticity. It is to provide a manufacturing method.

An object of the present invention is to prevent a positional deviation and the like from sagging during integral molding and sagging of parts, and to perform a single integral molding step. A closed type rotation sensor device by resin integral molding and a manufacturing method thereof. To provide.

An object of the present invention is to provide a hermetically sealed rotation sensor formed by resin integral molding which has good workability, can shorten the product development period, and can be automated, and also has an airtight and watertight structure of the lead wire drawing portion. An object is to provide a device and a manufacturing method thereof.

An object of the present invention is to provide a hermetically sealed rotation sensor device by resin integral molding, which is capable of improving the problems in the case of a hermetically sealed structure using an epoxy potting agent, and a manufacturing method thereof.

An object of the present invention is to provide a hermetically sealed rotation sensor device by resin integral molding, in which the lead wire lead-out portion can have good vibration damping properties, and a method of manufacturing the same.

[0013]

According to a first aspect of the invention for solving the above-mentioned problems, a magnetic core member and a permanent magnet are housed in a cylindrical hollow portion formed in a bobbin around which a coil is wound. In a hermetically-sealed rotation sensor device in which the sensor assembly is sealed with a mold resin, the bobbin is integrally molded so as to form a bag shape in which the distal end of the hollow portion is closed, and the permanent magnet. Is located at the tip of the hollow portion.

It is possible to leave the rear end of the hollow portion open and insert the permanent magnet and the magnetic core member into the hollow portion from here. In this case, the rear end may be sealed with the molding resin, and the coil wound around the bobbin can also be sealed with the molding resin. In this way, not only the permanent magnet and the magnetic core member in the hollow portion but also the coil and the lead-out portion of the coil can have a closed structure in which they are shielded from the outside air. The tip of the bobbin, that is, the tip of the hollow portion acts as the detection end of this sensor device. Here, since the permanent magnet is arranged at the tip of the hollow portion, a stronger magnetic field can be formed near the detection end, and a bag-shaped completely sealed portion by integrally forming the bobbin is formed at the tip of the hollow portion. Even if it is formed, this does not cause a problem of a decrease in the detection output level.

A second aspect of the present invention is characterized in that a sensor assembly, in which a magnetic core member and a permanent magnet are housed in a cylindrical hollow portion formed in a bobbin around which a coil is wound, is sealed with a molding resin. In the method for manufacturing a hermetically sealed rotation sensor device described above, the bobbin is formed by low-temperature resin molding so that the bobbin has a bag shape in which the tip of the hollow part is closed and a large number of small protrusions are formed on the outer surface of the flange part of the bobbin. And a step of assembling the sensor assembly by disposing the permanent magnet at the tip of the hollow portion of the molded bobbin and disposing the magnetic core member at the rear end of the permanent magnet, and the sensor assembly. In a molding die and a step of press-fitting a fluidized high-temperature molding resin into the molding die to seal the sensor assembly except the tip of the bobbin. .

When the molding resin is poured into the molding die, the molding resin in a fluidized state has the small projections formed on the outer surface of the flange portion of the bobbin act as a resistance against the inflow movement. Here, since the melting point temperature of the high-temperature mold resin is higher than that of the resin which is the bobbin material, the small protrusions melt due to the difference in heat capacity between them, and thus they melt well with the mold resin. As a result, the mold resin is brought into an extremely good close contact with the bobbin, and the hermeticity of the mold resin can be maintained for a long period of time. By molding the bobbin at a temperature lower than the normal molding temperature, the degree of adhesion with the molding resin can be further increased during integral molding.

Further, a product can be completed by one-time integral molding by providing an appropriate number of supporting members in an appropriate form for preventing positional displacement and falling during integral molding on the bobbin.

A third aspect of the present invention is characterized in that a sensor assembly, in which a magnetic core member and a permanent magnet are housed in a cylindrical hollow portion formed in a bobbin around which a coil is wound, is sealed with a mold resin. In the mold rotation sensor device, the bobbin is integrally formed so as to be a bag shape in which the distal end of the hollow portion is closed, and the permanent magnet is arranged at the most distal end in the hollow portion. The drawn-out end of the coiled coated wire is sealed with a polyamide resin. In this case, in particular, the polyamide-based resin can be brought into a state in which it is well adhered to the coating of the coated wire and the molding resin and has appropriate elasticity. Therefore, it is possible to provide a good vibration damping effect, and it is possible to satisfactorily maintain the sealed state of the drawn-out end of the drawn-out coated wire for a long period of time.

According to a fourth aspect of the present invention, a sensor assembly, in which a magnetic core member and a permanent magnet are housed in a cylindrical hollow portion formed in a coil-wound bobbin, is sealed with a mold resin. In the method for manufacturing a hermetically-sealed rotation sensor device according to claim 1, the bobbin is formed into a bag shape in which the distal end of the hollow portion is closed, and a large number of small protrusions are formed on the outer surface of the flange portion of the bobbin. And a step of assembling the sensor assembly by disposing the permanent magnet at the tip of the hollow portion of the molded bobbin and disposing the magnetic core member at the rear end of the permanent magnet, and the sensor assembly. A step of placing the solid body in a molding die; a step of press-fitting a fluidized high temperature molding resin into the molding die to seal the sensor assembly except the tip of the bobbin; Lead-out end of line Some in that a step of sealing by the hot melt filling of a polyamide resin.

In this case, in addition to the function and effect described in the second aspect of the invention, the polyamide-based resin adheres well to the coating of the coated wire and the molding resin, and has a moderate elasticity after curing. Become. Therefore, vibration-proof hardening can be provided, and the sealed state of the drawn-out end portion of the drawn-out coated wire can be favorably maintained for a long period of time.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a hermetically-sealed rotation sensor device according to the present invention, and FIG. 2 is A- of FIG.
A sectional view taken along the line A, and FIG. 3 are plan views of the sealed rotation sensor device shown in FIG.

Referring to FIGS. 1 to 3, in the closed type rotation sensor device 1, reference numeral 2 is a bobbin integrally formed by low temperature resin molding, and a cylindrical hollow portion 21 is formed at the center thereof. There is. As a synthetic resin material used for molding the bobbin 2, for example, a trade name “P” manufactured by Toray Industries, Inc.
PS A504X90 "is preferred, but of course other similar materials may be used. The distal end portion 21A of the hollow portion 21 has a closed bag shape, and the distal end portion 2
A flange portion 22 extending in a direction perpendicular to the axis of the bobbin 2 is integrally formed near 1A, and is formed in an annular recess 24 between the flange portion 22 and a block portion 23 formed at the rear end of the bobbin 2. The coil 3 is wound. In addition, on the outer surface 22A of the flange portion 22, a large number of small projections 22B are integrally formed with the flange portion 22 as shown in detail in an enlarged manner in FIG.

On the other hand, a closed end 21B is provided at the rear end of the hollow portion 21.
Are formed. The permanent magnet 4 and the magnetic core member 5 made of an appropriate magnetic material such as iron, nickel, and cobalt are inserted through the closing port 21B, the permanent magnet 4 is disposed at the tip 21A of the hollow portion 21, and the rear end of the permanent magnet 4 is inserted. The magnetic core member 5 is arranged in close contact with the. Here, in order to prevent the permanent magnet 4 and the magnetic core member 5 from playing in the hollow portion 21, the permanent magnet 4,
Each of the magnetic core members 5 is formed in a cylindrical shape having a diameter slightly smaller than the inner diameter of the hollow portion 21. In addition,
The cross-sectional shape of the hollow portion 21 is not limited to a circular shape, but may be a quadrangular shape or an arbitrary cross-sectional shape such as an appropriate polygonal shape. On the other hand, the cross-sectional shape of the permanent magnet 4 and the magnetic core member 5 is a shape corresponding to the cross-sectional shape of the hollow portion 21 or an appropriate shape different from the cross-sectional shape of the hollow portion 21 so as not to play in the hollow portion 21. Good. Reference numeral 25 indicates a cap member for inserting the permanent magnet 4 and the magnetic core member 5 into the hollow portion 21 and then fitting them to fix them.

A pair of terminals 31, 32 for electrically connecting the winding start end and the winding end of the coil 3 are formed in the block portion 23 formed at the rear end of the bobbin 2,
These terminals 31 and 32 are provided with a grommet 60A, and the core wires 61A and 6 of a pair of lead-out covered wires 61 and 62 are attached.
2A is soldered to form the sensor assembly 10. Here, the material of the grommet 60A is a polyamide (PA) resin, and the covered wires 61 and 62 are AVX rays. It should be noted that in the drawings, the illustration of the connection between the terminals 31 and 32 and the coil 3 is omitted.

Further, in the step of resin-molding the sensor assembly 10, in order to prevent the sensor assembly 10 from being displaced during the work in the mold for molding, the block portion 23 is provided with a column 23A. , 23B,
23C is integrally formed when the bobbin 2 is molded. Although three columnar columns are provided in this embodiment, the shape and the number of columns can be appropriately determined to suit the purpose and are not limited to those of this embodiment. Of course.

The sensor assembly 10 constructed as described above.
Is positioned and arranged in a mold for molding (not shown), and synthetic resin for molding which is fluidized by heating is press-fitted and filled in the mold to mechanically protect the sensor assembly 10 and at the same time to open the atmosphere. The outer cover 7 is formed so as to have a closed structure by being shielded from moisture, dust, etc., whereby the closed rotation sensor device 1 is obtained. As a synthetic resin material used for molding the mantle portion 7, for example, a trade name “PPS A503X03” manufactured by Toray is suitable, but it goes without saying that other similar materials may be used.

As can be seen from FIGS. 1 and 2, the mantle portion 7 is constructed so as to expose the tip portion 21A of the bobbin 2 and a part of the grommet 60A to the outside. As a result, the permanent magnet 4 housed inside the front end portion 21A acting as the detection end can generate a required magnetic field around the detection end via the bobbin 2, so that the output of the rotation sensor device 1 is lowered. Never. In addition, since the bobbin 2 is integrally formed, the tip portion 2 that is designed to look outside from the outer cover portion 7
It is possible to reliably prevent outside air, moisture, dust, and the like from entering the hollow portion 21 from around 1A.

In the process of sealing the sensor assembly 10 with the molding resin to form the outer jacket 7, since a large number of small projections 22B are provided on the outer surface 22A of the flange 22 of the bobbin 2, a synthetic resin for molding is used. The flow of the high temperature synthetic resin fluidized when press-fitted into the mold causes these small projections 22 to flow.
At B, the resistance is received, and the small protrusion 22B of the bobbin 2 is easily melted due to the difference in heat capacity between the low-temperature molded bobbin 2 and the molding synthetic resin for the outer jacket portion 7, and a part of the bobbin 2 and the outer jacket are covered. The synthetic resin for molding for the portion 7 is melted, and in particular, the adhesion between the outer surface 22A of the flange portion 22 of the bobbin 2 and the outer jacket portion 7 is significantly improved. As a result, the distal end portion 21A can be seen from the outer jacket portion 7 to the outside, but it is possible to reliably prevent outside air, moisture, dust, etc. from entering between the outer jacket portion 7 and the distal end portion 21A. ,
The hermeticity can be remarkably enhanced.

Further, since the bobbins 2 are provided with the columns 23A to 23C, when the sensor assembly 10 is arranged in a mold not shown, the columns 23A to 23C move the sensor assembly 10 in the mold. Since it is possible to prevent the above, it is possible to reliably and accurately perform the molding work of the mantle part 7 in one operation, and it is possible to reduce the number of processes and the yield, thereby reducing the cost and improving the quality. it can.

In the sealed rotation sensor device 1 shown in FIGS. 1 to 4, the covered wire 6 for connecting the coil 3 to the outside is provided.
The lead-out ends of Nos. 1 and 62 are sealed by covering a part of the grommet 60A provided therein when the outer cover 7 is formed with a mold resin. However, since the material of the grommet used in this type of device is basically a material that is not compatible with the molding resin for molding, the adhesion of this part may deteriorate due to aging. Airtightness may be a problem.

FIG. 5 and FIG. 6 show that the closed ends of the covered type rotation sensor device 1 shown in FIGS. An airtight structure that can provide a proper airtightness is shown. In the sealed rotation sensor device 100 shown in FIGS. 5 and 6, parts corresponding to the parts shown in FIGS. 1 to 4 are designated by the same reference numerals, and the description thereof will be omitted. In the closed rotation sensor device 100, the covered wires 61, 6
The outer cover portion 7 is formed by resin-molding the sensor assembly 10 without attaching a grommet to the pull-out end portion of 2. Then, the polyamide-based filler is coated on the wires 61, 6
By hot-melt filling the portion drawn from the outer jacket portion 2 of 2, the vicinity of the outer jacket portion 7 from which the covered wires 61, 62 are drawn out is covered, whereby the lead wire outer jacket portion 8 is formed. As the polyamide-based filler used for this purpose, a dimer acid-based polyamide resin (for example, trade name “Macromelt 6790”) can be used.

As described above, the coated wires 61 and 62 drawn from the outer jacket 7 after the outer jacket 7 is formed by resin molding.
Since the periphery of is covered by hot-melt filling with a polyamide-based filler to form the lead wire outer jacket 8 for the covered wires 61, 62, the polyamide-based filler in a melted state forms the covered wires 61, 62 and the outer jacket 7. Adhesion is good, and the airtightness and watertightness of the portion can be remarkably enhanced, and sufficient hermeticity can be secured. Furthermore, since the polyamide-based filler retains an appropriate elasticity after curing, the coated wires 61, 6
It can be deformed following the bending of 2 as well, giving the same flexibility as in the case of conventional rubber, and providing the same vibration damping effect as rubber. The workability of forming the outer sheath 8 for the lead wire by filling with the polyamide-based filler is easy, the development period of a new product can be shortened, and this process can be automated.

[0034]

The effects of the present invention are listed below. 1. It is possible to achieve long-term stability of hermeticity without increasing the number of parts. 2. By making the exposed portion of the detection end a bag-shaped end of the bobbin, it is possible to significantly improve the hermeticity without lowering the detection output. As a result, the permanent magnet can be downsized and the cost can be reduced. 3. The small protrusions become a resistance against the resin that has flowed during the integral formation, and melted out due to the difference in heat capacity, and the bobbin and the resin covering it melted well, and it became possible to greatly improve the sealing. 4. By molding the bobbin at a temperature lower than the normal molding temperature, it is possible to expect an effect of increasing the degree of adhesion between the mutually adhered surfaces during integral molding with a resin mold. 5. Providing a column on the upper part of the bobbin can prevent displacement and collapse during integral molding, and the product can be completed by one-time integral molding, resulting in a significant improvement in yield. 6. After forming the mantle part with a resin mold, the periphery of the covered wire drawn out from the mantle part is hot-melt filled with a polyamide-based filler to form the mandrel part for the lead wire with respect to the covered wire. The system-filling agent adheres well to the covered wire and the outer jacket, and the airtightness and watertightness of the area can be remarkably enhanced, and sufficient hermeticity can be secured. 7. Furthermore, since the polyamide-based filler retains an appropriate elasticity after curing, it can be deformed following the bending of the coated wire, giving the same flexibility as in the case of conventional rubber. , It is possible to give the same anti-vibration effect as rubber. 8. The workability of molding the outer jacket for the lead wire by filling with the polyamide-based filler is easy, the development period of a new product can be shortened, and the process can be automated.

[Brief description of the drawings]

FIG. 1 is a sectional view of a sealed rotation sensor device manufactured by a manufacturing method of the present invention for explaining an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view of the sealed rotation sensor device shown in FIG.

FIG. 4 is an enlarged view of a main part of the sealed rotation sensor device shown in FIG.

FIG. 5 is a plan view of a hermetically-sealed rotation sensor device for explaining a hermetically sealed structure in which a lead wire end portion is filled with a polyamide resin according to the present invention.

6 is a cross-sectional view of a main part showing a main part of a cross section taken along the line BB of FIG.

[Explanation of symbols]

 1, 100 Closed type rotation sensor device 2 Bobbin 3 Coil 4 Permanent magnet 5 Magnetic core member 7 Outer shell portion 8 Outer wire sheath portion 10 Sensor assembly 21 Hollow portion 21A Tip portion 22B Small protrusion 23A to 23C Strut 61, 62 Coated wire 61B, 62B coating

Claims (4)

[Claims] 1. A hermetically-sealed rotation sensor device in which a sensor assembly, in which a magnetic core member and a permanent magnet are housed in a cylindrical hollow portion formed in a bobbin around which a coil is wound, is sealed with a mold resin. The bobbin is integrally formed so as to form a bag shape in which the distal end of the hollow portion is closed, and the permanent magnet is arranged at the most distal end in the hollow portion. Mold rotation sensor device. 2. A hermetically-sealed rotation sensor device in which a sensor assembly having a magnetic core member and a permanent magnet housed in a cylindrical hollow portion formed in a bobbin around which a coil is wound is sealed with a mold resin. In the manufacturing method of, the step of obtaining the bobbin by low-temperature resin molding so that the bobbin has a bag shape in which the tip of the hollow part is closed and a large number of small projections are formed on the outer surface of the flange part of the bobbin, Assembling the sensor assembly by disposing the permanent magnet at the tip of the hollow portion of the bobbin and disposing the magnetic core member at the rear end of the permanent magnet; and disposing the sensor assembly in a molding die. A hermetically sealed rotation sensor device, comprising: a step; and a step of pressurizing fluidized high-temperature molding resin into the molding die to seal the sensor assembly except for a tip portion of the bobbin. Production method. 3. A hermetically-sealed rotation sensor device in which a sensor assembly formed by accommodating a magnetic core member and a permanent magnet in a cylindrical hollow portion formed on a bobbin around which a coil is wound is sealed with a mold resin. The bobbin is integrally formed so as to have a bag shape in which the distal end of the hollow portion is closed, the permanent magnet is arranged at the most distal end in the hollow portion, and the coiled wire for drawing out the coil is formed. A hermetically sealed rotation sensor device, characterized in that the drawn-out end portion thereof is sealed with a polyamide resin. 4. A hermetically-sealed rotation sensor device in which a sensor assembly formed by housing a magnetic core member and a permanent magnet in a tubular hollow portion formed on a bobbin around which a coil is wound is sealed with a molding resin. In the manufacturing method of, the step of obtaining the bobbin by low-temperature resin molding so that the bobbin has a bag shape in which the tip of the hollow part is closed and a large number of small projections are formed on the outer surface of the flange part of the bobbin, A step of assembling the sensor assembly by arranging the permanent magnet at the tip of the hollow part of the bobbin and arranging the magnetic core member at the rear end of the permanent magnet; and arranging the sensor assembly in a molding die. And a step of pressurizing fluidized high-temperature mold resin into the molding die to seal the sensor assembly excluding the tip of the bobbin, and the lead-out end of the lead wire of the coil is made of a polyamide-based material. Of resin Method of manufacturing a sealed type rotary sensor device characterized by comprising a step of sealing by Ttomeruto filling.