JP4207308B2 - Rotation detection sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotation detection sensor that detects the rotation of a rotation member, and relates to the structure of the rotation detection sensor.
[0002]
[Prior art]
Conventionally, the rotation detection sensor is known to be composed of a cap, a detection block equipped with the sensor, and a connector terminal group having a flange as a mounting portion, and these are assembled into a magnetic rotation speed sensor. Is disclosed, for example, in WO 97/4318.
[0003]
In the configuration of the sensor shown here, since the detection block is put into the cap, the outer diameter of the sensor requires the thickness of the detection block and the cap, and a seal member is disposed on the outer periphery of the cap. The thickness of the cap in the radial direction increases, and the outer diameter of the sensor increases. For this reason, when the sensor described above is applied, for example, as a sensor for detecting the rotational state of the rotary shaft of an automatic transmission in a vehicle, the sensor passes so as not to interfere between complicated hydraulic paths. Mounting, avoiding interference with a rotating body such as a gear, and the like, and it is desired to reduce the diameter in the radial direction.
[0004]
Japanese Patent Laid-Open No. 7-198736 discloses a sensor in which the outer diameter of the sensor is not increased and a sealing member is provided on a flange portion provided on the outer periphery of the case body. The sensor disclosed in this publication has a structure in which a terminal and a magnetoelectric conversion element are integrally insert-molded on a resin base member, and this is housed in a case body. Since the case body performs sealing, an outer flange portion of the case body is formed, and a triangular seal is provided at a position where the flange portion is formed.
[0005]
[Problems to be solved by the present invention]
In the configuration shown in the above Japanese Patent Application Laid-Open No. 7-198736, since the triangular seal is taken at the position where the flange portion is formed, the sensor itself can have a small diameter, but since it is not a shaft seal, the rotation sensor can be attached. If it is insufficient, the sensor will float against the fixing member that fixes the sensor, or the seal member may be bitten, resulting in a seal failure and an increase in the distance between the sensor and the rotor, making rotation detection impossible. In some cases, the desired interval cannot be secured. Further, in the triangular seal, stress acts on the flange portion of the case body. For example, when the triangular seal is used under a high temperature condition for a long time, it may be deformed and a seal failure may occur.
[0006]
Therefore, the present invention has been made in view of the above problems, and it is a technical problem to provide a sensor having a reliable sealing function and a configuration in which the sensor does not increase in the radial direction. To do.
[0007]
[Means for Solving the Problems]
The technical means taken in order to solve the above technical problem include a sensor for detecting the rotation of the rotating member, a holder to which the sensor is fixed and a terminal is electrically connected to the sensor, and the holder to be accommodated. The case body has a bottomed cylindrical case body with a thin end portion , an outer peripheral groove and a connector, and the case body side end portion is thin and the case body has a thin outer diameter. In the assembled state, the diameter is the same, and when the holder is stored, the case body is welded to the case body at a position where it is thinned, and the slip-off prevention section is provided at the end in the longitudinal direction. Shi performing a housing which is integrally formed in the longitudinal direction, a seal between said predetermined member when the sensor relative to the predetermined member is attached to the outer circumferential groove has inserted the case member provided therein with the It is to have a seal member.
[0008]
With the above configuration, since the housing having the outer peripheral groove and the connector in the longitudinal direction is integrally formed with the case body, it is not necessary to increase the thickness of the seal member in the case body, and the diameter can be reduced in the radial direction. It becomes possible. In addition, since the seal member is attached to the outer peripheral groove of the housing in the longitudinal direction of the case body, it can be used as a shaft seal, and there is no problem like the conventional triangular seal, and the seal can be performed reliably. It becomes possible to make a configuration.
[0009]
In this case, if the groove diameter of the outer peripheral groove is smaller than the inner diameter of the case body, it is possible to ensure sealing performance and to reduce the diameter in the radial direction.
[0010]
If the case body is provided with a welded portion near the end, and the welded portion is formed with a diameter smaller than the outer diameter of the housing, when the housing is molded by resin molding, Since it becomes possible to make it the same diameter, it becomes possible not to become large in radial direction.
[0011]
In addition, if the concave and convex portions are formed in the welded portion, the surface area becomes larger due to the concave and convex portions when the housing is resin-molded, so that heat transfer during resin molding is easily transmitted to the case body and easy to weld. It becomes possible to do.
[0012]
In addition, a recess is provided in a part of the outer shape of the holder, a seal member is provided in the recess, and the holder is inserted into the case body and welded to the housing at the welded portion, so that double sealing becomes possible. , It is possible to securely seal the part where the sensor is provided.
[0013]
Furthermore, if the terminal is made thicker in the resin-molded housing than the connection part with the sensor, the terminal will be thicker at parts where strength is required and parts where strength is not required. By changing it, it becomes possible to improve the reliability and productivity of the sensor.
[0014]
If the case body is provided with a drop prevention portion and is integrated with the housing in the drop prevention portion, the strength can be improved in the longitudinal direction.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a diagram illustrating a configuration of the rotation detection sensor SEN. In FIG. 1, the rotation detection sensor SEN is made of a metal member (brass), and a terminal 8 whose one end is bent in the vertical direction is inserted and fixed to a holder 5 integrally formed of resin (PPS). . In the holder 5, a sensor 1 having an electronic component 4, a magnet 3 for generating magnetic flux, and a detection element 2 having a Hall IC or the like inside or integrally therewith is electrically connected and fixed to the terminal 8 by soldering or the like. Has been. The sensor 1 detects the rotation of a rotating member 30 having a gear surface on the outer periphery or a rotating member provided with radial slits in a radial direction in a non-contact manner. Specifically, the magnetic flux generated around the magnet by the magnet 3. However, the change is detected by the detection element 2 under the condition that the magnetic flux density is changed by the rotation of the rotating member 30. In this case, the rotating member 30 does not perform a rotational movement, and the linear movement of the rack can be detected by the detection element 2 even in a rack that performs a linear movement.
[0017]
The holder 5 to which the sensor 1 is fixed is housed in a bottomed cylindrical case body 6 made of resin (nylon 6). In the vicinity of the end of the case body 6, a welded portion 61 and a drop prevention portion 62 are provided. The welded portion 61 has a thickness approximately half the thickness d of the outer diameter of the case body 6 (the outer diameter of the case body 6. Smaller diameter) d / 2, and an uneven portion 61a is formed in an annular shape. Further, a slip-off preventing portion 62 provided on the outer periphery of the case body 6 at a position slightly apart from the welded portion 61 has a groove formed in the vicinity of the end portion of the case body 6 as shown in FIG. It is formed in a T-shape so that the resin flows and the resin flows around in the circumferential direction. The shape of the drop prevention part 62 is T-shaped in the present embodiment, but is not limited to this, and may be, for example, L-shaped or C-shaped. It is formed for the purpose of preventing the removal of 10 and improving the strength in the longitudinal direction.
[0018]
In the longitudinal direction of the case body 6, the housing 10 is formed integrally with the case body 6 by resin molding (nylon 66). The housing 10 is formed by inserting the holder 5 into the case body 6 and then insert-molding the terminal 8 fixed to the holder 5, and has a flange portion 13 having a connector 11 and a sensor mounting portion. An outer peripheral groove 14 to which the seal member 9 is attached is integrally provided on the outer diameter of the housing. The groove diameter of the outer circumferential groove 14 is smaller than the inner diameter of the case body 6.
[0019]
The terminal 8 is led to a connector 11 integrally formed with the housing 10, and a rotation signal (square wave) detected by the sensor 1 is detected from the connector 11. Such a rotation detection sensor SEN has a sensor detecting portion inserted into a sensor mounting hole of a predetermined member (for example, a housing of an automatic transmission), and a fastening member such as a bolt at a mounting hole 13 provided in the flange portion 12. Fixed. In the sensor fixed state, a region on the right side of the flange portion 12 shown in FIG. 1 is a seal region, and in order to maintain the seal performance of this portion, a seal member 9 such as an O-ring is fitted in the outer peripheral groove 14 of the housing 10, and the connector The side seal is maintained. Further, since the housing 10 is integrally formed in the longitudinal direction with respect to the inside of the sensor, the welded portion 61 provided on the case body 6 is melted by the heat at the time of molding the housing. The sealing performance is maintained.
[0020]
For the case body 6, for example, nylon 6 is used at a molding temperature of 230 ° C., but nylon 66, PPS, PBT, or the like may be used. The welded portion 61 provided in the case body has a concavo-convex portion 61a having a concavo-convex shape so that it can be easily fused at the time of molding the housing, and has a structure in which the resin is passed to the prevention portion 61 in order to strengthen the strength. (See FIG. 2). Thereby, the joining strength between the case body 6 and the housing 10 is increased, and an elongated sensor that is small in the radial direction can be made.
[0021]
In this case, the resin may be wrapped around the case body 6 in the slip-off prevention portion 62 or may be all around or part of it. Here, nylon 66 having a molding temperature of 280 ° C. is used as the secondary molding resin for molding the housing 10, but PPS, PBT, or the like can be used. It is desirable that the resin for molding the case body 6 and the resin for molding the housing 10 have different melting points. For the resin bonding, it is also possible to use a resin having an adhesive action with an additive or the like. It is not limited. Further, a connector is provided for taking out a signal from the sensor 1, but a wire may be used, and the seal member 9 attached to the housing outer peripheral groove 14 may be any member as long as it can maintain a sealing property such as an O-ring. Further, by forming the flange portion 12 by secondary molding, the angle of the flange portion 12 can be freely set, and therefore, it is possible to cope with it without changing the shape and configuration of the detection portion housed in the case body 6.
[0022]
Next, a method for manufacturing the rotation detection sensor SEN will be described.
[0023]
The rotation detection sensor SEN inserts the terminal 8 into a mold and first makes the holder 5 by resin molding. When the holder 5 is completed, an electronic component (resistor, capacitor, etc.) 4 is placed on the circuit mounting portion of the holder 5 and fixed by soldering or the like. Thereafter, the sensor 1 having the detection element 2 and the magnet 3 therein is electrically connected to the longitudinal end of the terminal 8 by a joining means such as soldering. In this case, the detection element 2 electrically connected to the terminal 8 may be a Hall IC, a Hall element, a magnetoresistive element, a GMR, or the like, and these elements may be connected to the terminal 8 without being directly connected to the terminal 8. Can be attached to an insert molded resin substrate, MID (three-dimensional resin molded substrate), or the like.
[0024]
After the sensor 1 and the necessary electronic components 4 are attached to the holder 5, the holder 5 is inserted into the case body 6 with one end of the terminal 8 exposed to the connector side exposed. In this case, the case body 6 and the holder 5 are press-fitted if the outer diameter of the holder substantially coincides with the case body 6. This is to prevent secondary molding resin from entering the case and adversely affecting the detection portion on which the detection element 2 and the electronic component 4 are mounted when the housing 10 is secondarily molded. The detection part is inserted, and the housing 10 having the flange part 12 and the connector 11 in the longitudinal direction of the case body 6 is resin-molded. At this time, the outer peripheral groove 10 is simultaneously molded to the outer diameter of the housing 10. When molding the housing (during secondary molding), the holder 5 is pushed into the back of the case body 6 by molding pressure to protect the sensor 1 so that the detection unit is not damaged or the sensor performance is not deteriorated. A flange portion 5a is provided on one side surface of the holder 5 and is engaged with the end portion of the welded portion 61 of the case body 5 so as to be positioned so as not to enter the depth direction more than a certain amount.
[0025]
Thus, after the housing 10 is molded by resin molding, the seal member 9 is attached to the outer circumferential groove 14 provided on the outer periphery of the housing and having a groove diameter smaller than the inner diameter of the case body 6, thereby completing the rotation detection sensor SEN. . In the rotation detection sensor SEN made in this way, a detection unit is inserted into a predetermined member (for example, a housing of an automatic transmission) in a state where a gap of a predetermined distance is maintained from the rotation member 30 so as to detect the rotation of the rotation member 30. In this state, it is fixed by a bolt or the like through the mounting hole 13 of the flange portion 12.
[0026]
Next, a second embodiment will be described with reference to FIG. This second embodiment is basically the same as the first embodiment shown in FIG. 1 except that the position where the welded portion 61 is provided, the shape of the holder 25, the seal member 26 provided in the holder 25, and the connector shape. Mainly different.
[0027]
The welded portion 61 is formed in the longitudinal direction of the case body 26, and the welded portion 61 has a smaller diameter than the outer diameter of the case body as in FIG. An uneven portion 61a is formed at the tip of the welded portion 61, and the welded portion 61 is welded to the case body 26 when the housing is molded, and is integrated with the case body 26 in the longitudinal direction.
[0028]
In addition, the structure shown in FIG. 3 has a sealing function on the holder side in addition to the sealing by welding the welded portion 61 a by secondary molding of the housing 20 to the case body 26. This is formed by forming a circumferential recess 25a on the outer shape of the holder 25, attaching a seal member 26 such as an O-ring to the recess 25a, and providing a recess 25b at the end of the holder in the longitudinal direction in which the terminal 28 extends. By performing sealing with resin potting 27 on 27, or by inserting a rubber bush to perform sealing, a double sealing structure can be taken with respect to the inside of the sensor. That is, in this sensor rotation detection SEN, when the welded part 61 is used with a gas or liquid having good permeability or when used under a high pressure condition, they enter from the outside, and further, the outer peripheral surface of the holder. Alternatively, even when a medium with good permeability enters from the portion where the terminal 28 extends from the holder 25, the detection unit on which the electronic element 4 or the sensor 1 is placed is surely secured by the seal member 26 and the seal member 27 provided in the recess 27. It becomes possible to protect, and the reliability of a sensor improves.
[0029]
In addition, here, a metal member (brass) having good conductivity whose thickness has been changed by pressing is used for the terminal 28, and the resin pressure at the part inserted into the housing 20 is larger at the time of molding than the holder part. In order to receive, the plate thickness is increased, and the plate thickness is reduced at the portion connected to the detection element 2 and the electronic component 4. In this way, the thickness of the terminal 28 can be changed at an arbitrary position, and the portion requiring strength can be increased.
[0030]
【effect】
According to the present invention, since the housing having the outer peripheral groove and the connector in the longitudinal direction is integrally formed with the case body, it is not necessary to increase the thickness of the seal member in the case body, and it is reduced in the radial direction. Can do. In addition, since the seal member is attached to the outer peripheral groove of the housing in the longitudinal direction of the case body, it can be used as a shaft seal, and there is no problem like the conventional triangular seal, and the seal can be performed reliably. Can be configured.
[0031]
In this case, if the groove diameter of the outer peripheral groove is smaller than the inner diameter of the case body, the sealing performance can be ensured and the diameter can be reduced in the radial direction.
[0032]
If the case body is provided with a welded portion near the end, and the welded portion is formed with a diameter smaller than the outer diameter of the housing, when the housing is molded by resin molding, It can be made the same diameter and can be prevented from becoming large in the radial direction.
[0033]
In addition, if the concave and convex portions are formed in the welded portion, the surface area becomes larger due to the concave and convex portions when the housing is resin-molded, so that heat transfer during resin molding is easily transmitted to the case body and easy to weld. Become.
[0034]
In addition, a recess is provided in a part of the outer shape of the holder, a seal member is provided in the recess, and the holder is inserted into the case body and welded to the housing at the welded portion, so that double sealing becomes possible. , It is possible to securely seal the part where the sensor is provided.
[0035]
Furthermore, if the terminal is made thicker in the resin-molded housing than the connection part with the sensor, the terminal will be thicker at parts where strength is required and parts where strength is not required. By changing, the reliability and productivity of the sensor can be improved.
[0036]
If the case body is provided with a removal prevention portion and is integrated with the housing in the removal prevention portion, the strength is improved in the longitudinal direction.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a rotation detection sensor according to a first embodiment of the present invention.
FIG. 2 is an external view of a rotation detection sensor according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a configuration of a rotation detection sensor according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sensor 2 Detection element 3 Magnet 5 Holder 6 Case body 8 Terminal 9, 26 Seal member 10 Housing 11 Connector 14 Outer peripheral groove 25a, 25b Recess 30 Rotating member 61 Welding part 62 Detach prevention part

Claims (2)

A sensor for detecting the rotation of the rotating member;
A holder to which the sensor is fixed and a terminal is electrically connected to the sensor;
The bottomed cylindrical case body in which the holder is housed and the end portion is thin ,
The case body has an outer peripheral groove and a connector, and the case body side end is thin, and the case body has the same outer diameter as the outer diameter of the case body. On the other hand, a housing integrally formed in the longitudinal direction by a welded portion with the case body provided at the thinned position and a slip-off preventing portion provided at an end in the longitudinal direction;
A rotation detection sensor comprising: a seal member that seals with the predetermined member when the case body that is attached to the outer peripheral groove and in which the sensor is provided is inserted into the predetermined member . The said removal prevention part becomes T shape which protruded into the inside of the said case body provided in a longitudinal direction, The circumference | surroundings of the said prevention part are in contact with resin which forms the said case body. Rotation detection sensor.

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