JP2015125117A - Rotation detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation detection device capable of simplifying a design process and improving productivity.SOLUTION: A rotation detection device 100 includes: a middle case 3 equipped with a magnet 11 and magnetic detection means 12; and an outer case 4 having a storing space 43 for storing the middle case 3. The middle case 3 is provided with a press-in rib 33 for pressing-in and holding the middle case 3 in the outer case 4. The storing space 43 is equipped with a hollow portion 43a for storing the magnet 11 and the magnetic detection means 12 disposed on a bottom portion 42 side of the outer case 4 than the press-in rib 33, and a filling portion 43b provided on an opening portion 41 side than the press-in rib 33 and filled with a filling member 5 by the press-in rib 33. The hollow portion 43a is sealed by a sealing member 6 disposed on the hollow portion 43a side than the press-in rib 33.

Description

  The present invention relates to a rotation detection device that detects rotation of a measurement object.

  A conventional rotation detection device is disclosed in Patent Document 1, for example. The rotation detection device includes a middle case having a magnet and magnetic detection means, an outer case having a storage space for storing the middle case, and a rotation member provided with a filling member such as epoxy disposed in the storage space. It was a detection device.

JP 2008-164439 A

  However, the rotation detection device described in Patent Document 1 has a structure in which the inner case is accommodated in the outer case, and then the filling member is filled in the outer case, but the filling member is a thermosetting resin. Since there is a risk that stress will be applied to the magnetic detection means (Hall IC) during curing, and the sensitivity of the magnetic detection means may be reduced due to the difference in thermal expansion of the void that is not filled with the filling member in the outer case. There is a problem that the structure and the structure of the middle case must be carefully considered, and the design process becomes complicated.

  Therefore, an object of the present invention is to provide a rotation detection device that can solve the above problems, simplify the design process, and improve productivity.

  The rotation detection device of the present invention is a rotation detection device including an inner case having a magnet and magnetic detection means, and an outer case having a storage space for storing the inner case. A press-fitting rib that is press-fitted and held in the middle case, and wherein the storage space is a hollow part that stores the magnet and the magnetic detection means disposed on the bottom side of the outer case with respect to the press-fitting rib, and the press-fitting rib And a filling portion that is provided closer to the opening than the press-fitting rib and is filled with the filling member, and the hollow portion is hermetically sealed by a sealing member that is disposed closer to the hollow portion than the press-fitting rib. It is a thing.

  With the above configuration, the present invention can provide a rotation detection device that can achieve the intended purpose, simplify the design process, and improve productivity.

1 is a top view of a first embodiment of the present invention. The side view of the embodiment. Sectional drawing of the III-III line in FIG. The perspective view of the embodiment. The perspective sectional view of the embodiment. The principal part expanded sectional view of the embodiment.

  Hereinafter, a rotation detection device 100 according to an embodiment of the present invention will be described with reference to the accompanying drawings. 4 and 5, the filling member 5 is not shown for easy understanding.

  The rotation detection device 100 according to the present embodiment mainly includes a magnetic head 1, a circuit board 2, an inner case 3, an outer case 4, a filling member 5, and a sealing member 6.

  The magnetic head 1 is composed of a magnet 11 and magnetic detection means 12. The magnet 11 has a cylindrical shape. The magnetism detecting means 12 is a housing in which a Hall IC, a magnetoresistive element (MR element) or the like is built in a housing made of a synthetic resin, detects a change in magnetism generated by the magnet 11 and is in contact with the magnet 11. Arranged.

  The circuit board 2 is a hard circuit board in which a predetermined wiring pattern is formed on an insulating substrate such as a glass cloth base epoxy resin or ceramic. In addition to a hard circuit board, a flexible circuit board (FPC) in which a predetermined wiring pattern is formed on a flexible material can be applied. On the circuit board 2, various electronic components (not shown) such as a noise absorbing capacitor and a signal amplifier circuit are mounted on the magnetic detection means 12. A lead 12a bent in a substantially L shape of the magnetic detection means 12 is electrically connected to one end side of the circuit board 2 via solder or the like, and a lead terminal described later is connected to the other end side. 7 is electrically connected via solder or the like. Therefore, the detection signal detected by the magnetic detection means 12 is transmitted from the circuit board 2 to the lead terminal 7 and taken out to the outside.

  A synthetic resin material such as SPS, PBT, and PPS can be applied to the middle case 3, and as shown in FIG. 3, a head portion 31 and a body portion 32 are integrally provided.

  In the head portion 31, the magnet 11 and the magnetic detection means 12 are provided on the front end surface side of the middle case 3, and a mounting portion for disposing the circuit board 2 in a part of the head portion 31 and the trunk portion 32. 31c is provided.

  Lead terminals 7 formed of a conductive material are insert-molded mainly in the body portion 32 of the middle case 3, and a connector portion 8 is integrally provided at one end of the middle case 3. A plurality of lead terminals 7 are provided for supplying power to the magnetic detection means 12 and for outputting signals from the magnetic detection means 12. The lead terminal 7 is drawn out so that one end protrudes to the outside at the connector portion 8 and the other end can be electrically connected to the circuit board 2. The connector portion 8 electrically connects each lead terminal 7 to an external device, and the fitting direction with the external device coincides with the opening direction of the storage space of the outer case 4 described later.

  In the middle case 3, press-fitting ribs 33 are formed on the outer peripheral surface of the body portion 32 over the entire circumference, and the middle case 3 is press-fitted and held in the outer case 4.

  The middle case 3 is provided with a recess 36 for accommodating the sealing member 6. The recess 36 is formed on the outer peripheral surface of the middle case 3 over the entire circumference. The sealing member 6 is made of an elastic member such as rubber, and is, for example, an O-ring. This sealing member 6 ensures the airtightness of the hollow part 43a mentioned later.

  The outer case 4 can be made of the same synthetic resin material as that of the inner case 3, and has a bottomed cup shape with a substantially U-shaped cross-section in the longitudinal direction, and has an opening 41 at one end. The other has a bottom 42 and constitutes a storage space 43 for storing the magnetic head 1 and the circuit board 2.

  The storage space 43 is provided on the opening 41 side of the press-fit rib 33 and the hollow portion 43a for storing the magnet 11 and the magnetic detection means 12 disposed on the bottom 42 side of the outer case 4 with respect to the press-fit rib 33. And a filling portion 43b formed by preventing the filling member 5 from entering the hollow portion 43a by the rib 33. The hollow portion 43a is formed by the sealing member 6 disposed on the hollow portion 43a side of the press-fitting rib 33. The airtightness of 43a is secured. In addition, by stopping the penetration of the filling member 5 with the press-fitting ribs 33, the filling member 5 does not touch the sealing member 6, and the sealing property of the sealing member 6 can be ensured.

  The filling member 5 can be applied with a somewhat fluid epoxy resin or silicone resin, and the press-fitting rib 33 provided in the middle case 3 is provided closer to the opening 41 than the position in contact with the outer case 4. As a result, the filling member 43 is filled with the filling member 5 that is prevented from entering the hollow portion 43a.

  By filling the filling member 5 in the filling portion 43b, the filling space 5 containing the magnetic head 1 is not filled with the filling member 5 as in the conventional case, and only the filling portion 43b not containing the magnetic head 1 is filled. Since the structure filled with the member 5 can be adopted, the complicated structure of the middle case 3 and the outer case 4 is not required, and the filling amount of the filling member 5 can be reduced to less than half depending on the model, thereby reducing the design process. It can be simplified and productivity can be improved.

  In the step of filling the filling member 5 into the filling portion 43b, the filling member 5 is filled by inserting the nozzle of the filling member 5 filling device 5 from above the opening 41 of the outer case 4 into the storage space 43. The portion 43b is filled.

  Further, the middle case 3 includes a pair of arm portions 34. This arm part 34 is comprised by the front-end | tip part 34a and the base 34b. The base portion 34 b of the arm portion 34 extends in the direction of the outer case 4. In the present embodiment, the base 34b extends to a point-symmetrical position with the middle case 3 as the center. In other words, the base portions 34b are 180 degrees different from each other in the extending direction. Further, the distal end portion 34 a extends from the position where the base portion 34 b contacts the inner surface of the outer case 4 toward the opening 41 side. The end portion of the distal end portion 34 a is positioned lower than the end portion of the opening 41 of the outer case 4.

  The outer case 4 is provided with a caulking portion 44 at the end portion of the opening portion 41 to come into contact with the tip end portion 34a of the arm portion 34 by heat caulking. Since the filling part 43b is filled with the filling member 5, the inner case 3 can be reliably held in the outer case 4, so that the vibration resistance can be improved.

  Further, by receiving the distal end portion 34 a of the arm portion 34 by the crimping portion 44, the intermediate case 3 is assembled to the outer case 4, and the distal end portion 34 a is held by the crimping portion 44, thereby cutting the sealing member 6. It is possible to prevent the middle case 3 from being pulled out of the outer case 4 by force.

  Further, the arm part 34 is separated from the body part 32 provided with the press-fitting rib 33, and a separation part 35 is provided between the arm part 34 and the body part 32. When the filling member 5 is injected, the separation portion 35 functions as a flow path through which the filling member 5 flows. Therefore, when the filling member 5 is injected from one location of the opening 41 of the outer case 4, the filling member 5 can flow through the separation portion 35 to fill the filling portion 43 b, and the filling of the filling member 5 to be injected However, the arm portion 34 is not hindered. By providing the separation portion 35 serving as a flow path, the filling member 5 can be injected at one place, and productivity can be improved.

  Further, the outer case 4 includes a concave portion 45 on the outer peripheral portion thereof, and includes another sealing member 9 that ensures airtightness between the actual machine and the outer case 4 in the concave portion 45. The other sealing member 9 is also made of an elastic member such as rubber like the sealing member 6 and is, for example, an O-ring. The arrangement position of the other sealing member 9 substantially coincides with the position of the sealing member 6 arranged in the middle case 3, so that the thin portion 46 formed by the recess 45 of the outer case 4 is the other. The sealing member 9 may be deformed in the direction of the middle case 3 and the airtightness between the actual machine and the outer case 4 may be impaired, but by adjusting the position of the other sealing member 9 to the position of the sealing member 6, The deformation of the outer case 4 can be suppressed by the reaction force of the sealing member 6, and the airtightness between the outer case 4 and the actual machine can be maintained.

  As described above, according to the present invention, in the rotation detection device 100 including the middle case 3 including the magnet 11 and the magnetic detection means 12 and the outer case 4 having the storage space 43 for storing the middle case 3, A press-fitting rib 33 that is press-fitted and held in the outer case 4 is provided in the middle case 3, and the storage space 43 is a hollow that stores the magnet 11 and the magnetic detection means 12 that are disposed closer to the bottom 42 of the outer case 4 than the press-fitting rib 33. And a filling portion 43b provided on the opening 41 side of the press-fit rib 33 and filled with the filling member 5 by the press-fit rib 33. The hollow portion 43a is disposed on the hollow portion 43a side of the press-fit rib 33. By sealing the hollow portion 43a with the sealing member 6, the magnetic detection means 12 is accommodated without filling the storage space containing the magnetic detection means with the filling member as in the prior art. A structure in which only the unfilled filling portion 43b is filled with the filling member 5 can be adopted, the complicated structure of the middle case 3 and the outer case 4 is not required, and the filling amount of the filling member 5 can be reduced, so that the design process can be reduced. It can be simplified and productivity can be improved.

  The middle case 3 includes at least a pair of arm portions 34 extending in the inner circumferential direction of the outer case 4, and a portion of the arm portion 34 faces the opening 41 side of the outer case 4 and the opening portion of the outer case 4. The outer case 4 is provided with a caulking portion 44 that is heat caulked so as to hold the distal end portion 34a of the arm portion 34 at the opening thereof. The case 3 can be reliably held on the outer case 4 and the vibration resistance can be improved.

  Further, the arm portion 34 is provided with a separation portion 35 formed by separating the filling member 5 from the portion provided with the sealing member 6, so that the injection of the filling member 5 is not hindered by the arm portion 34. Since the filling member 5 can be injected at a location, productivity can be improved.

  Further, the outer case 4 includes a recess 45 on the outer peripheral portion thereof, and includes another sealing member 9 that ensures airtightness in the recess 45, and the other sealing member 9 is disposed at the middle case 3. The thin-walled portion 46 formed by the recess 45 of the outer case 4 is deformed by the reaction force of the sealing member 6 by being coincident with or substantially coincident with the position of the disposed sealing member 6. Since it can suppress, the airtightness of the outer case 4 and an actual machine can be maintained.

  The present invention is applicable to a rotation detection device that detects rotation of a measurement object.

DESCRIPTION OF SYMBOLS 100 Rotation detection apparatus 11 Magnet 12 Magnetic detection means 3 Middle case 33 Press-fit rib 34 Arm part 34a Tip part 35 Separation part 4 Outer case 41 Opening part 42 Bottom part 43 Storage space 43a Hollow part 43b Filling part 44 Fastening part 45 Recessed part 5 Filling Member 6 Sealing member 9 Other sealing member

Claims (4)

In a rotation detecting device comprising an intermediate case having a magnet and magnetic detection means, and an outer case having a storage space for storing the intermediate case, the press-fitting rib for press-fitting and holding the intermediate case in the outer case Provided in the middle case, the storage space is provided on the opening side of the press-fitting rib, the hollow part for storing the magnet and the magnetic detection means arranged on the bottom side of the outer case with respect to the press-fitting rib. And a filling portion filled with a filling member by the press-fit rib, wherein the hollow portion seals the hollow portion by a sealing member disposed on the hollow portion side from the press-fit rib. apparatus. The middle case includes at least a pair of arm portions extending in the inner circumferential direction of the outer case, and the arm portion is positioned at a position lower than the opening portion of the outer case while a portion thereof is directed toward the opening portion of the outer case. 2. The rotation according to claim 1, further comprising: a front end portion positioned at a position, wherein the outer case includes a caulking portion that is heat caulked to press the front end portion of the arm portion at an opening portion thereof. Detection device. The rotation detection device according to claim 1, wherein the arm portion includes a separation portion formed by separating the filling member from a portion including the sealing member. The outer case is provided with a concave portion on the outer peripheral portion thereof, and is provided with another sealing member that ensures airtightness in the concave portion, and the arrangement position of the other sealing member is arranged in the middle case. The rotation detection device according to claim 1, wherein the rotation detection device matches or substantially matches the position of the sealing member.

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