JP4716103B2 - Manufacturing method of rotation sensor - Google Patents

Description

  The present invention relates to a method for manufacturing a rotation sensor.

  As a known rotation sensor, one shown in FIG. 6 is known (see Patent Document 1).

  The rotation sensor 100 is provided, for example, so as to face the rotor 101 that rotates together with the vehicle tire. When the rotor 101, which is a magnetic body, rotates, the magnetic flux density passing through the Hall IC 102 (detection element) changes due to the unevenness of the gears. By detecting this change in magnetic flux density by the Hall IC 102, the rotation speed of the rotor 101 is detected, and the rotation sensor functions as a vehicle speed sensor.

  In the rotation sensor 100, a cylindrical holder 103 is integrally formed with the terminal 104 by resin molding. One end 104 ′ of the terminal 104 passing through the holder 103 is electrically connected to the Hall IC 102 via a terminal 106 provided on the substrate 105. The other end 104 ″ of the terminal 104 is electrically connected to the core wire of the cable 107. Then, after the holder 103 is fitted into the cylindrical case 108, the cap-shaped sealing member 109 is The case 108 and the holder 103 are liquid-tightly sealed by resin molding, and at this time, the terminal 104 and the cable 107 connected to the terminal 104 are also integrally molded. The terminal 104 electrically connected to the Hall IC 102 is embedded in the holder 103 and the sealing member 109.

  In the above-described rotation sensor 100, the case 108 and the holder 103 are sealed by the sealing member 109, and the terminal 104 is embedded in the holder 103 and the sealing member 109, so that the portion where the Hall IC 102 is provided. It has a sealed structure.

However, there is a difference in the coefficient of thermal expansion between the holder 103 and the sealing member 109 and the terminal 104 due to the difference in the material. Therefore, when the rotation sensor 100 is used in a temperature cycle environment in which the ambient temperature is repeatedly increased and decreased, the holder 103, the sealing member 109, and the terminal are depending on the degree of expansion and contraction. There was a possibility that a gap was formed at the boundary with 104. Therefore, there is a possibility that moisture, oil, or the like entering from the outside of the sensor through the core wire of the cable 107 may reach the site where the Hall IC 102 is provided via this gap. Such intrusion of moisture or oil causes electric corrosion or short-circuiting between terminals in the Hall IC 102, and there is a concern that the characteristics of the Hall IC 102 may be deteriorated and the performance of the rotation sensor 100 may be deteriorated.
JP-A-6-82478

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have ensured that water and oil can enter the site where the detection element is provided even when the rotation sensor is used in a temperature cycle environment. Therefore, a rotation sensor as shown in FIG.

  The rotation sensor 10 shown in FIGS. 3-5 was assembled in the following procedures.

  First, the Hall IC 22 is electrically connected to one end 23a of the terminal 23 by welding or the like. Next, the terminal 23 connected to the Hall IC 22 is press-fitted into the insertion hole 24 c provided in the base 24 a of the holder 24, and these members assembled together are accommodated in the case 21. Then, the assembly of the sensor body 20 is completed by fitting the plate 25 into the opening 21a of the case 21 so that these members are covered.

  After the assembly of the sensor main body 20 is completed, the mold part 30 is formed on the case 21 via the plate 25 by resin molding (see FIG. 3). That is, the opening 21 a of the case 21 is sealed by the mold part 30 via the plate 25. At the time of the resin molding, the terminal 23, the flat plate terminal 31 connected to the terminal 23, and the cable 32 connected to the flat plate terminal 31 are also integrally formed, so that the terminal 23 and the flat plate terminal 31 are attached to the mold member 30. Buried.

  However, it has been found that the manufacturing method according to such a procedure has the following disadvantages.

  First, in assembling the sensor body 20, it is necessary to slide the plate 25 and the holder 24 inserted through the terminal 23 with care so that the Hall IC 22 is not peeled off. In addition, since the IC terminal portion 22a is made of a thin and soft material such as a copper wire, when the holder 24 is press-fitted into the case 21, the terminal is bent and the position of the Hall IC 22 is displaced and may not enter the case 21.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method of manufacturing a rotation sensor capable of improving the assembly workability of the sensor body and improving the yield.

The rotation sensor manufacturing method of the present invention covers a detection element accommodated in a bottomed case, a terminal electrically connected to the detection element, an elastic body press-fitted into the case, and an opening of the case. and a cover member, the terminal is a method for producing a rotation sensor is inserted into the elastic body and the cover member, a detection element and the terminal are electrically connected, and the terminal elastic body and the cover member by sliding the fixed elastic body and the cover member to the tip portion of the terminal in the insertion state into bets, the temporary sliding step of the detection element and the elastic body is arranged to be positioned at a gap, the terminal and case temporary assembly process together for accommodating the sensing element case and the elastic member and the cover member inserted through a cable by pressing the cover member and the elastic member fixing the distal end portion of the terminal And having a resin molding process for forming the mold portion and the press-fitting step of press-fitting the elastic member to the case, the opening of the bottomed casing via a cover member by resin molding to mate with.

  In the rotation sensor manufacturing method of the present invention, it is preferable that the cover member of the rotation sensor is provided with an engaging portion that engages with the opening of the case.

  Furthermore, in the manufacturing method of the rotation sensor of the present invention, it is preferable that the terminal of the rotation sensor is a substantially round bar.

  The method of manufacturing the rotation sensor according to the present invention is characterized in that the holder is positioned in two stages when the sensor body is assembled. That is, the first stage is a temporary sliding process in which the holder is brought close to the detection element with a minute gap along the terminal whose tip is fixed, and the second stage is such that the bottom surface of the case comes into contact with the bottom surface of the detection element. After the holder is temporarily accommodated in the case, the holder is press-fitted to a predetermined position in the case with the terminal fixed and is fitted into the case.

  In the manufacturing method of the present invention, since the terminal is fixed with a chuck or the like until the assembly of the sensor body is completed, the plate and the holder are integrally slid (moved relatively) on the terminal. . Therefore, highly accurate position control is possible. In the first stage, since the holder is relatively moved only to a position where a minute gap is formed between the holder that is an elastic body and the detection element, at this stage, the detection element is maintained in a welded posture, The holder does not deform the detection element or cause a disconnection disconnection of the weld.

  In the second stage, the terminal is fixed, and the holder only needs to be pressed into the minute gap and the predetermined elastic deformation in the axial direction. Therefore, the terminal does not move according to the elastic deformation of the holder. Therefore, it is possible to avoid the problem that the holder applies a load to the detection element and breaks the detection element.

  As described above, since the reliability with respect to the assembly of the sensor body is improved, the quality of the rotation sensor can be stabilized, and at the same time, the productivity can be improved.

  Hereinafter, a preferred embodiment of a method for manufacturing a rotation sensor according to the present invention will be described with reference to the drawings.

  FIG. 3 is a schematic cross-sectional view showing the structure of the rotation sensor 10 described above. The rotation sensor 10 roughly includes a sensor body 20 and a mold part 30. The sensor body 20 is provided so as to face the rotor 11 that is a magnetic body. When the rotor 11 rotates, the rotation is detected by the Hall IC 22 accommodated in the case 21 of the sensor body 20. The signal detected in the sensor body 20 is transmitted to the flat plate terminal 31 embedded in the mold part 30 via the terminal 23. A core wire of a cable 32 is connected to the flat terminal 31 by welding. The cable 32 is connected to a control controller (not shown).

  Hereinafter, the sensor body 20 will be described with reference to FIG. 4 is a cross-sectional view taken along the line II-II in FIG.

  The sensor body 20 includes a case 21, a Hall IC 22, a terminal 23, a holder 24, and a plate 25.

  The case 21 has a bottom and a substantially cylindrical shape. The opening 21a of the case 21 is provided with a plurality of claw portions 21b (only one number is attached in the drawing).

  The Hall IC 22 (detection element) is accommodated in the case 21. The Hall IC 22 is a known magnetic detection element that outputs a signal corresponding to the magnetic flux density that passes. The Hall IC 22 includes a magnet (not shown).

  A pair of terminals 23 are provided and have a substantially round bar shape. One end 23a of the terminal 23 is electrically connected to the Hall IC 22 by welding. The other end 23b of the terminal 23 is electrically connected to the flat plate terminal 31 (see FIG. 3) by welding or the like.

  The holder 24 is an elastic body made of rubber and having a substantially cylindrical shape. The holder 24 is fitted into the case 21 by press fitting. The pair of terminals 23 are inserted into the holders 24 by press-fitting.

  Hereinafter, the detailed structure of the holder will be described with reference to FIG. FIG. 5 is a partially enlarged view around the holder 24 in FIG.

  The holder 24 is fitted into the case 21 by press fitting at the base 24a. A seal portion 24b is provided on the outer periphery of the base portion 24a. The seal portion 24b is provided so as to protrude in the radial direction over the entire outer periphery of the base portion 24a, and has a so-called lip shape. The base 24a of the holder 24 is fitted to the case 21 in a state where the seal portion 24b is elastically deformed in the radial direction. That is, the shape of the seal portion 24b including the press-fitting allowance (elastic deformation) is set so that the base portion 24a of the holder 24 is fitted into the case 21 by press-fitting. In this case, the outer diameter of the base 24 a of the holder 24 is formed to be apparently larger than the inner diameter of the case 21.

  The base portion 24a is provided with a pair of insertion holes 24c so as to penetrate in the axial direction. The terminal 23 is inserted into the insertion hole 24c by press-fitting. Seal portions 24d are provided on the inner periphery of the insertion hole 24c. The seal portion 24d is provided so as to protrude in the radial direction over the entire inner circumference of the insertion hole 24c, and has a so-called lip shape. In the insertion hole 24c of the holder 24, the terminal 23 is inserted in a state where the seal portion 24d is elastically deformed in the radial direction. That is, the shape of the seal portion 24d including the press-fitting margin (elastic deformation) is set so that the terminal 23 is inserted into the insertion hole 24c of the holder 24 by press-fitting. In this case, the inner diameter of the insertion hole 24 c of the holder 24 is formed to be apparently smaller than the outer diameter of the terminal 23.

  The plate 25 (cover member) has a substantially disk shape. As shown in FIG. 4, the plate 25 is provided with a pair of insertion holes 25 a corresponding to the insertion holes 24 c of the holder 24. Terminals 23 are respectively inserted through the insertion holes 25a. A plurality of engaging portions 25 b (only one number is attached in the figure) are provided on the outer periphery of the plate 25 corresponding to the claw portions 21 b of the case 21. The engaging portion 25 b is engaged with the claw portion 21 b of the opening 21 a of the case 21, so that the opening 21 a of the case 21 is covered with the plate 25. In this case, the holder 24 is interposed between the Hall IC 22 and the plate 25 in a state of being elastically deformed in the axial direction. In other words, the plate 25 is in pressure contact with the Hall IC 22 via the holder 24. The holder 24 has an axial dimension including a press-fitting allowance (elastic deformation) so as to be interposed between the Hall IC 22 and the plate 25 via an elastic force.

  That is, the rotation sensor 10 is characterized in that a holder 24 made of an elastic material such as rubber is used instead of the holder 103 (FIG. 6) formed by resin molding of the known rotation sensor 100 as a holder for supporting the terminal 23. It was. And the seal part 24d is provided in the outer peripheral part of the holder 24 contact | abutted with the case 21, and the inner peripheral part of the insertion hole 24c which penetrates the terminal 23, and waterproof / oil-proof performance is ensured by the elastic deformation part of the seal part 24d. At the same time, the detection element 22 can be fixed and anti-vibrated by the elastic deformation of the holder 24 in the axial direction.

  The rotation sensor of the present invention as described above can be manufactured according to the flowchart shown in FIG. 1 and the procedure shown in FIG. FIG. 2 illustrates each process. (A) shows a Hall IC connection process, (b) shows a temporary slide process, (c) shows a case temporary assembly process, and (d) shows a press-fitting process. The left of each process is a side view showing an outline after the completion of the process, and the right figure is a schematic sectional view.

  First, in step S <b> 1, the pair of terminals 23 are inserted into the insertion holes 24 c of the holder 24.

  Next, in step S2, each terminal 23 protruding from the holder 24 is inserted into the insertion hole 25a of the plate 25 so that the upper surface of the holder 24 and the lower surface of the plate 25 come into contact with each other. 23 is projected by a predetermined length.

  Subsequently, in step S3, the upper end portion of the terminal 23 is fixed, and the lower portion of the terminal 23 protruding from the holder 24 is crushed with a press or the like. One end 23a is formed.

  In step S4, the IC terminal portion 22a of the Hall IC 22 is electrically connected to the one end 23a of the oval shape by spot welding or soldering.

  In step S5, the terminal 23 portion (portion A in FIG. 2B) protruding from the plate 25 is fixed by an appropriate method such as chucking. The fixing by the chuck in step S5 may be performed before step S3, and may also serve as fixing of the terminal 23 in step S3.

  In step S6, as shown in FIG. 2B, with the end of the terminal 23 fixed and the Hall IC 22 suspended, the upper surface 25b of the plate 25 is pressed to move the plate 25 and the holder 24 toward the Hall IC 22 side. Move by a predetermined amount. However, at this time, a minute gap D is provided between the bottom surface 24e of the holder and the top surface 22c of the Hall IC 22 so as not to contact the Hall IC 22. The minute gap D should be as small as possible within a range where the bottom surface 24e of the holder and the top surface 22c of the Hall IC 22 do not contact each other. In this embodiment, this step S6 is a temporary slide process.

  Subsequently, in step S7 which is a case temporary assembly process, the temporary assembly 28 (state of FIG. 2B) in which the Hall IC 22 is connected to the terminal 23 and the plate 25 and the holder 24 are temporarily slid as described above. It accommodates in the case 21 with a bottom (FIG.2 (c)). At this time, the fixing portion A may be lowered to insert the temporary assembly 28 into the case 21, or the temporary assembly 28 may be raised while the temporary assembly 28 is fixed to accommodate the temporary assembly 28. Also good. However, in step S7, the minute gap D provided in step S6 is held, and the bottom surface 22e of the Hall IC 22 is disposed so as to contact the inner surface 21e of the bottom portion 21d of the case 21. At this stage, the plate 25 and the opening of the case 21 are in a semi-fitted state, but the minute gap D is not maintained at this stage, that is, the plate 25 is completely fitted into the opening of the case 21. Then, the flat plate portion 23a of the terminal 23 also moves downward together, and at the same time it contacts the Hall IC 22, a load is applied and the Hall IC 22 may be damaged. Therefore, it is desirable to strictly control the lowering amount of the temporary assembly 28 or the raising amount of the case 21 using a jig and / or a measuring instrument. In this step, it goes without saying that a normal shape is maintained without deforming the thin and soft IC terminal portion 22a, and that the rotation direction or the left-right direction of the Hall IC 22 is arranged in a predetermined direction. .

  After the case is assembled to the temporary assembly 28, in step S8, the upper surface 25b of the plate 25 is pressed again while the terminal 23 is fixed, and the plate 25 is completely engaged with the opening 25a of the case 21. And the holder 24 are press-fitted into the case 21 (referred to as re-sliding) (FIG. 2D). Thus, the holder 24, which is an elastic body (rubber), is elastically deformed by pressing the holder 24 into the case 21 until the plate 25 and the opening 21a of the case 21 are completely fitted. In this state, both the inner peripheral surface of the case 21 and the outer peripheral surface of the terminal 23 are in contact with each other, and the minute gap D provided in step S6 disappears, and the Hall IC 22 is pressed by the amount of elastic deformation in the axial direction of the holder 24. Can be fixed and anti-vibration.

  Further, the opening 21a of the case 21 is provided with a retaining protrusion (claw part) 21b as shown in FIG. 2D, and is engaged with an engaging part 25b formed on the plate 25, so that the holder 24 It is desirable that the temporary assembly 28 is not pulled out by an axial load due to elastic deformation. In the present embodiment, steps S7 and S8 are press-fitting processes.

  As described above, until the step S8, the end of the terminal 23 is fixed with a chuck or the like. However, since the end of the terminal may be firmly chucked, the terminal surface may be damaged. It is desirable to remove the part. In step S9, the chuck portion of the terminal 23 is cut and removed by a press or the like. In this way, the assembly of the sensor body 20 is completed.

  In step S10, a flat plate terminal 31 having a lead wire (cable) connected to a control device (not shown) is welded to the distal end portion of the terminal 23. Subsequently, in step S11, resin is passed through the plate 25 to the opening 21a of the case 21. A mold part is formed by molding. That is, steps S10 and S11 are resin molding processes, and the rotation sensor 10 (FIG. 3) is obtained by forming a mold part. Such a resin molding step is not particularly limited, and may be performed using the same resin and means as in the past. According to the rotation sensor manufacturing method of the present invention as described above, it is possible to dramatically improve the productivity of the rotation sensor and to obtain a rotation sensor that exhibits stable performance for a long period of time.

  In addition, the manufacturing method of the rotation sensor of this invention is not limited to said embodiment, It can change in the range which does not deviate from the main point of this invention. For example, in the above-described embodiment, the terminal is inserted into the insertion hole of the holder and the plate, then the oval shape is formed, and the Hall IC is connected. In this case, the flatness of the oval shape of the pair of terminals is kept constant, so that it can be easily connected to the two square terminals of the Hall IC (welding is possible even if the terminals are laterally displaced). On the other hand, it is necessary to pay attention so that spatter generated when the Hall IC is welded to the terminal does not damage the peripheral members such as the holder and the plate. For this reason, after fixing Hall IC to a terminal, you may make it insert a terminal in the insertion hole of a holder and a plate.

  A method of manufacturing a rotation sensor according to the present invention includes a detection element housed in a bottomed case, a terminal electrically connected to the detection element, and an elastic body press-fitted into the case. It is suitable as a method for manufacturing a rotation sensor inserted through an elastic body.

It is a flowchart explaining the manufacturing procedure of embodiment. It is a schematic diagram explaining each step of the flowchart of FIG. (A) is step S1-S4, (b) is step S5-S6, (c) is step S7, (d) is a schematic diagram explaining step S8. In addition, the left of each figure shows a side surface and the right shows a cross section. It is a cross-sectional schematic diagram of the rotation sensor suitable for this Embodiment. It is a schematic diagram which shows the II-II cross section of FIG. FIG. 4 is a partial enlarged view of the periphery of the holder in FIG. 3. It is sectional drawing which shows the structure of a well-known rotation sensor.

Explanation of symbols

10: Rotation sensor 21: Case 21a: Opening 22: Hall IC (detection element) 23: Terminal 24: Holder (elastic body) 25: Plate (cover member) 25b: Engagement part 30: Mold part

Claims (3)

A detection element housed in a bottomed case, a terminal electrically connected to the detection element, an elastic body press-fitted into the case, and a cover member covering the opening of the case , A method of manufacturing a rotation sensor in which a terminal is inserted through the elastic body and the cover member ,
And the detection element and the terminals are electrically connected, and the slide and the elastic member and the cover member and the terminal is fixed to the tip portion of the terminal in a state of being inserted into said elastic member and the cover member A provisional sliding step in which the detection element and the elastic body are disposed so as to be positioned with a gap therebetween;
And Case temporary assembly process together housing the detecting element to the case and the elastic member and the cover member inserted through the terminal,
A press-fitting step of press-fitting the elastic body into the case so as to fit the case by fixing the tip of the terminal and pressing the cover member and the elastic body;
And a resin molding step of forming a mold part by resin molding through the cover member in the opening of the bottomed case. The rotation sensor manufacturing method according to claim 1 , wherein the cover member is provided with an engaging portion that engages with an opening of the case.   The method of manufacturing a rotation sensor according to claim 1, wherein the terminal is a substantially round bar.

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