JPH0472575A - Manufacture of sensor device - Google Patents

Abstract

PURPOSE:To enhance the water resistance and vibration resistance of a sensor device by molding a sensor assembled body from an intermediate molding comprising an internal protecting member formed on the outer peripheral surface of an output wire, and forming an outer protecting member from an assembled body. CONSTITUTION:An output wire 20 is disposed in a mold and a synthetic resin is pressed into the mold so as to form an internal protecting member 21 on the outer peripheral face of the outer cover of the output wire 20. The end portion 8b of the output terminal 8 of a preassembled body is connected to the conductive portion of the output wire on which the protecting member 21 is formed and also a case 1 in which a sensor element portion 11 is stored is inserted into the center hole 2a of a bracket 2 so as to form a sensor assembled body. The sensor assembled body is disposed in the mold and a synthetic resin is pressed therein and an outer protecting member 22 is molded to form a sensor device 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a sensor device used for detecting rotational speed, and more particularly, to a method for manufacturing a sensor device with high waterproofness and vibration resistance. .

BACKGROUND OF THE INVENTION A rotation sensor for detecting the rotational speed of a wheel provided on a vehicle is generally attached via a bracket to a portion of the vehicle body that is exposed to a harsh environment, such as within a tire house. Therefore, such a rotation sensor is required to have waterproof properties, rust resistance against salt water, etc., vibration resistance against vehicle body vibration, and shock resistance. Further, cost reduction is also desired from the economic point of view.

By the way, a rotation sensor has a structure in which a sensor element part consisting of a magnet, a coil, etc. is housed inside an external case, and in order to improve the vibration resistance and impact resistance of the rotation sensor, a protection member made of synthetic resin is formed. Insert the output wire into the hole,
After being combined with the sensor element part within the outer case, the output line and the outer case are fixed by molding resin into the outer case. However, this structure has the drawback that moisture or the like enters through a small gap created between the protective member and the output line or another member adjacent thereto, resulting in corrosion and deterioration of the sensor element portion.

Problems to be Solved by the Invention Therefore, Japanese Patent Application Laid-Open No. 63-140912 discloses a structure in which a sealing layer made of adhesive is formed in the gap between the protective member and the output line, and the gap between the protective member and the adjacent member. is proposed. However, the structure shown in this publication increased the number of manufacturing steps and did not necessarily provide sufficient waterproofness.

An object of the present invention is to provide a method for manufacturing a sensor device that is double waterproof while maintaining sufficient vibration resistance.

Means for Solving the Problems The method for manufacturing a sensor device according to the present invention includes the steps of arranging an output line having an outer covering made of synthetic resin in a first mold, and placing the output wire in the first mold. a first resin molding step of press-fitting a fluidized first synthetic resin to form an internal protective member on the outer circumferential surface of the outer covering of the output line; and an intermediate obtained by the first resin molding step. a step of taking out the molded body from the first molding die and connecting the output end of the sensor element part housed in the case and the conductive part of the output line to form a sensor assembly; and the step of molding the sensor assembly. A step of arranging the three-dimensional object in a second mold, and press-fitting a fluidized second synthetic resin into the second mold to form at least the opening of the case and the front Δ self-sensor element part. a second resin molding step for forming an external protection member that covers a connection portion between the output end of the output line and the conductive portion of the output line and a part of the internal protection member; and removing the final molded body from the first and second molds.

Preferably, in this method of manufacturing a sensor device, the outer peripheral surface of one end of an outer covering made of synthetic resin provided on an output wire is roughened, and the roughened outer peripheral surface of the outer covering of the output wire is It is preferable to form an internal protection member on a part or all of.

The internal protective member is formed directly on the outer peripheral surface of the output wire's outer sheath by press-fitting the fluidized synthetic resin into the working mold, so the inner protective member is fused onto the output wire's outer sheath. The connection between the output line and the internal protection member becomes tight. Also,
The external protection member that covers the opening of the case, the connection between the output end of the sensor element section and the conductive part of the output line, and a part of the internal protection member is also made by press-fitting fluidized synthetic resin into the mold. Since the sensor device is formed by forming the sensor device, the adhesion to the output line and the internal protection member is further improved, and water and the like are prevented from entering the inside of the sensor device. Further, the internal protection member and the external protection member have the function of sufficiently protecting the inside of the sensor device from external vibrations and deformation. In particular, by roughening the outer peripheral surface of the output wire and forming the internal protective member on part or all of the outer peripheral surface, the adhesion between the outer covering of the output wire and the internal or external protective member is further strengthened. be done.

Embodiment Hereinafter, an embodiment of the method for manufacturing a sensor device according to the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a sectional view of a sensor device manufactured by the manufacturing method of the present invention. Although not shown, in the present invention, the output line 20
A first molding die is used to form the inner protection member 21 on the outer covering of the mold, and a second molding die is further used to form the outer protection member 22 thereon.

The outer covering 20c of the output line 20 is formed of a suitable outer covering resin such as polyurethane resin, and a conductive portion 20b is drawn out from the inner covering 20d disposed inside the outer covering 20c at the end 20a.

For example, a fluorine-based mold release agent is used for the outer coating 20c of the output line 20, so that the surface thereof is smooth.

Therefore, when integrally molding the outer covering 20c of the output line 20, the inner protection member 21, and the outer protection member 22,
Adhesion was not sufficient. Therefore, the outer covering 20c
By roughening the outer circumferential surface of the output line 20 and forming the inner protection member 21 on a part or all of the outer circumference of the roughened outer sheath 20c, the outer sheath 20c of the output line 20 and the inner protection i'1 are
Adhesion with the member 21 or the external protection member 22 can be strengthened.

A coating device 23 shown in FIG. 5 is rotatably attached to a shaft 24 of a motor. Reference numeral 23a is a hole into which the output line 20 is inserted, and has sharp teeth in the shape of a screw or ring. Further, 23b is a hole into which the portion 20f from which the outer covering 20c is removed is inserted when the output line 20 is inserted.

To roughen the surface of the output line 20, first
into the hole 23a of the rotating coating processing device 23, and insert it until the end 20a of the output wire 20 hits the step 23c. Next, the output line 20 is pulled out from the hole 23a. Since the diameter of the hole 23 and the diameter of the output wire 20 are almost the same, as shown in FIG. Fine uneven scratches 20e are formed on the surface.

Next, the output line 20 is placed in the first mold, and the fluidized first synthetic resin is press-fitted into the molding cavity of the first mold. An elastic resin material is used for the first synthetic resin, and here, a polyurethane resin of the same quality as the outer covering 20c of the output line 20 is used. After solidification of the first synthetic resin, the intermediate molded body is taken out from the first mold. As shown in FIG. 2, this intermediate molded body is formed with an internal protection member 21 that partially covers a flaw 20e formed on the outer circumferential surface of the outer sheath 20c of the output line 20. Note that a plurality of annular protrusions 21a are formed on the outer peripheral surface of the internal protection member 21 to improve adhesion. By the resin molding method described above, the inner surface 21b of the internal protection member 21 is fused to the outer covering 20c of the output wire 20, and the space between the inner surface 21b and the outer covering 20c of the output wire 20 is sufficiently sealed.

Next, a preassembly to be connected to the output line 20 is formed.

The preassembly includes a cylindrical case 1 and a sensor element section housed within the case 1. Sensor element section 11
A pole piece 3 having a detection end 3a protruding from an opening 1b formed in an end 1a of the case 1, and a non-magnetic bobbin 4 in which a hole 4a for accommodating the pole piece 3 is formed.
, a coil 5 wound around the outside of the pobbin 4, a core 7 disposed opposite the flange 3b of the pole piece 3,
It has a magnet 6 disposed between the flange 3b and the core 7, and a pair of terminals 8 connected to the conductive wire of the coil 5. The cavity of the case 1 in which the sensor element part 11 is housed is sealed with a filler 10 such as a thermosetting epoxy resin, and the end 8b of the output terminal 8 projects outward from the filler 10.

The end 8b of the output terminal 8 of the above pre-assembly is connected by solder to the conductive part 20b of the output line 20 on which the internal protection member 21 is formed, and the case 1 is inserted into the center hole 2a of the bracket 2 to provide a sensor. A pair of holes 2b are formed in the bracket 2 in order to attach the sensor device to a tire house (not shown) forming the assembly.

Next, the sensor assembly is placed in a second mold, and the fluidized second synthetic resin is press-fitted into the second mold to form the outer protection member 22.

The second synthetic resin is a thermoplastic nylon resin blended with glass fiber. Case 1 filled with filler 10
The connection portion between the end 8b of the opening IC1 output terminal 8 and the conductive portion 20b of the output line 20 and a part of the internal protection member 21 are covered with the external protection member 22 and integrated. Also,
The bracket 2 is also coated and integrated. After the second synthetic resin has solidified, the resulting final molded body is removed from the second mold as a sensor device.

The sensor device manufactured by the above method is attached to the tire house of the vehicle via the bracket 2, and the sensor device is moved by the rotation of the magnetic gear located adjacent to the detection end 3a of the pole piece 3. The speed of the wheels is detected by detecting the magnetic field. Although the above embodiment describes an electromagnetic generation type sensor device, the sensor device manufactured according to the present invention can also be applied to a sensor device of a detection type using a magnetically sensitive element. Moreover, it is applicable not only to rotation detection but also to various uses.

Effects of the Invention According to the present invention, the internal protection member 2 is formed by a simple method of press-fitting a fluidized synthetic resin into a mold.
1 and an outer protection member 22, the inner protection member 21 is fused to the outer sheath 20c of the output line 20, and the outer protection member 22 covers the opening 1c of the case 1, the inner protection member 21, etc. Since it is formed to cover the sensor device, the inside of the sensor device can be protected with high sealing performance. In particular, since the outer protection member 22 is formed on the textured outer peripheral surface (the annular protrusion 21a) of the inner protection member 21, the inner protection member 21 and the outer protection member 22 have higher sealing properties. Therefore, it is possible to sufficiently prevent water and the like from entering the interior of the sensor device. In addition, since the internal protection member 21 and the external protection member 22 are tightly adhered to each other, the interior of the sensor device can be protected against deformation from the outside. In addition, by forming the internal protection member 21 on a part or all of the outer circumferential surface of the roughened outer sheath 20c, the adhesion between the outer sheath 20C of the output line 20 and the internal protection member 21 or the external protection member 22 is improved. can be further strengthened.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a sensor device obtained by the manufacturing method of the present invention, Fig. 2 is a side view showing a state in which an internal protection member is formed on the output line, and Fig. 3 shows the outer covering of the output line. FIG. 4 is a front view, FIG. 4 is a side view thereof, and FIG. 5 is a sectional view of the coating processing apparatus. l...case, lc...opening, 8...output terminal, 1]
...Sensor element section, 20...Output line, 20b6. Conductive part, 20c...Outer coating, 21...Inner protection member, 22...
・External protection member, Figure 2

Claims (2)

[Claims] (1) A step of arranging an output wire having an outer covering made of synthetic resin in a first mold, and press-fitting the fluidized first synthetic resin into the first mold, and a first resin molding step of forming an internal protection member on the outer circumferential surface of the outer covering of the output line; and the intermediate molded body obtained by the first resin molding step is taken out from the first molding die, and a case is formed. forming a sensor assembly by connecting the output end of the sensor element part housed in the inner part and the conductive part of the output line; and placing the sensor assembly in a second mold. , a fluidized second synthetic resin is press-fitted into the second mold to form at least the opening of the case, the connecting part between the output end of the sensor element part and the conductive part of the output line, and a second resin molding step of forming an external protection member that covers a part of the internal protection member; and a step of taking out the final molded body obtained by the second resin molding step from the second mold. A method of manufacturing a sensor device comprising: (2) a step of roughening the outer circumferential surface of one end of the output wire having an outer covering made of synthetic resin; and a step of placing the output wire in a first mold; first resin molding, in which a fluidized first synthetic resin is press-fitted into a mold to form an internal protection member on part or all of the outer peripheral surface of the roughened outer covering of the output wire; step, the intermediate molded body obtained by the first resin molding step is taken out from the first molding mold, and the output end of the sensor element part housed in the case and the conductive part of the output line are connected. connecting and molding a sensor assembly; placing the sensor assembly in a second mold; and press-fitting a fluidized second synthetic resin into the second mold. a second resin forming an external protection member that covers at least the opening of the case, the connection between the output end of the sensor element section and the conductive part of the output line, and a part of the internal protection member; A method for manufacturing a sensor device, comprising: a molding step; and a step of taking out the final molded body obtained by the second resin molding step from the second mold.