JP2018059930A - Stroke sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stroke sensor that enables a circuit substrate having a magnetism detection element mounted to be efficiently arranged.SOLUTION: A stroke sensor A, which has a magnet 4, and follows a detected body, and detects an amount of movement of a detection shaft 1 reciprocating around an origin position O by a magnetism detection element 5, comprises: a housing 2 that slidably supports the detection shaft 1 with rotation of the detection shaft regulated, and is composed of a non-magnetism metallic material; a circuit substrate 51 that has the magnetism detection element 5 mounted on a surface; wiring 53 that is connected to a surface on a mounted side of the magnetism detection element 5 of the circuit substrate 51, and is led outside the housing 2; a concave shape substrate holding unit 21e that accommodates the circuit substrate 51 outside the housing 2; and a filling member 52 that fills the substrate holding unit 21e, and covers the circuit substrate 51. The substrate holding unit 21e is configured to provide a step shape at a part opposing the surface of the circuit substrate 51.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a stroke sensor.

  As a stroke sensor for detecting the amount of movement of a moving body such as a lever of an automobile or a motorcycle, for example, there is one disclosed in Patent Document 1. The stroke sensor includes a shaft that follows the movement of the object to be detected, a housing in which the shaft is accommodated, a magnet provided at one end of the shaft, a magnetic detection element that is provided in the housing and detects a magnetic field change of the magnet, An origin return mechanism that returns the shaft to the origin position after the shaft has reciprocated, and detects the amount of movement of the detected object that reciprocates in the axial direction by a change in the magnetic field.

JP 2014-149188 A

  In the stroke sensor described in Patent Document 1, in order to make the magnetic detection element watertight, a circuit board on which the magnetic detection element is mounted and a wiring connection portion from the circuit board to the outside are filled with a filling member.

  It is preferable that the filling member has a filling amount as small as possible in order to reduce the weight of the stroke sensor as well as to require time to cure. On the other hand, since there are various restrictions such as magnetic detection elements, wiring connection locations, and wiring arrangements, it has been desired to arrange them efficiently.

  An object of the present invention is to provide a stroke sensor capable of efficiently arranging a circuit board on which a magnetic detection element is mounted, paying attention to the above-mentioned problems.

In order to achieve the above object, a stroke sensor according to the present invention comprises:
A stroke sensor that has a magnet and detects the amount of movement of the detection shaft that reciprocates around the origin position following the object to be detected by a magnetic detection element,
A housing made of a non-magnetic metal material that slidably supports the rotation of the detection shaft; and
A circuit board for surface mounting the magnetic sensing element;
A wiring connected to the surface of the circuit board on which the magnetic detection element is mounted and routed out of the housing;
On the outside of the housing, a concave substrate holding portion that accommodates the circuit board;
A filling member that fills the substrate holding part and covers the circuit board;
With
The substrate holding part is characterized in that a step shape is provided at a location facing the surface of the circuit board.

Further, the circuit board is screwed and held in the board holding portion so that a connection portion of the magnetic detection element and the wiring is not in contact with the housing.

Further, the circuit board is provided with a plurality of notches.

Further, the substrate holding part, a bottom part facing the magnetic detection element,
It has a recess facing the connection portion of the wiring provided outside the magnetic detection element and deepened deeper than the bottom.

Further, the substrate holding part has a bottom part facing the magnetic detection element, and a pair of concave parts dug deeper than the bottom part,
Each of the pair of recesses is provided symmetrically to each other,
One of the pair of recesses is opposed to a connection portion of the wiring provided outside the magnetic detection element.

Further, the substrate holding part has a boss protruding higher than the bottom part,
The boss has a symmetrical shape,
The boss has a screw hole formed by cutting.

Further, a notch for routing the wiring to the outside of the substrate holding portion is formed on the side wall of the substrate holding portion by cutting.

  According to the present invention, it becomes a stroke sensor which can arrange a circuit board which mounts a magnetic sensing element efficiently.

The figure which shows the stroke sensor before providing the filling member in 1st Embodiment of this invention. Sectional drawing (XX sectional drawing) of the stroke sensor of embodiment same as the above. Sectional drawing (YY sectional drawing) of the stroke sensor of embodiment same as the above. Sectional drawing of the stroke sensor of 2nd Embodiment of this invention. The (a) front view and (b) sectional view (ZZ sectional view) which show the substrate holding part of an embodiment same as the above. Sectional drawing of the stroke sensor of embodiment same as the above. The front view which shows the board | substrate holding part of embodiment same as the above.

  Hereinafter, a stroke sensor according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  As shown in FIGS. 1 and 2, the stroke sensor A according to the first embodiment of the present invention is a stroke sensor A that detects the amount of movement of the detection shaft 1 that reciprocates around the origin position O following the detected object. In this case, the housing 2 is slidably supported by restricting the rotation of the detection shaft 1, and the detection shaft 1 provided between the detection shaft 1 and the housing 2 after detecting the movement amount is moved to the origin. An origin return mechanism 3 for returning to the position O, a magnet 4 provided on the side surface of the detection shaft 1, and a movement amount detected from a change in a magnetic field provided on the housing 2 opposite to the magnet 4 as the detection shaft 1 moves. And a magnetic detection element 5 configured to be configured.

  The detection shaft 1 according to the present embodiment is a detection medium that follows the movement of the detected body. For example, the detection shaft 1 is connected to the detected body and is transmitted with an external force, and reciprocates in the axial direction. The detection shaft 1 includes a first shaft 11 and a second shaft 12, and the first shaft 11 and the second shaft 12 are connected to each other.

  The first shaft 11 is made of a nonmagnetic metal having a certain degree of rigidity, and is typically made of austenitic SUS (stainless steel). The first shaft 11 includes three large diameter portions 11a having different diameters, a medium diameter portion 11b, and a small diameter portion 11c.

  The small-diameter portion 11c protrudes outward from the housing 2 (first housing 21), and is connected to the detected body. For example, a male screw 11d is formed and connected to the detected body with the screw and follows.

  The large diameter portion 11a and the large diameter portion 11b are disposed in the housing 2 (first housing 21), and rotation is restricted by a sliding support portion described later between the housing 2 (first housing 21). It is supported so that it can slide.

  The large-diameter portion 11a has a female screw portion 11e for connecting to the second shaft 12 on the end surface side opposite to the small-diameter portion 11c.

  The end face of the large-diameter portion 11a is engaged with a piston 31 of the origin return mechanism 3 described later, and transmits the pushing force to the piston 31 when the first shaft 11 is pushed. As a result, a drag force is generated by the spring 32 via the piston 31, and the first shaft 11 can be returned to the origin position O.

  The large-diameter portion 11a has a substantially D-shaped cross section at the end opposite to the small-diameter portion 11c. Thereby, the rotation of the first shaft 11 is regulated in cooperation with the shape of the housing 2 (first housing 21).

  The middle diameter portion 11b is formed with a magnet housing portion 11f. A magnet 4 is accommodated in the magnet accommodating portion 11f and is fixed by an adhesive or the like. In this case, a moisture-curing resin adhesive such as silicon or epoxy can be used as the adhesive, and the adhesive is filled so as to fill a gap between the concave magnet housing portion 11f and the magnet 4, and further, the adhesive in the magnet housing portion 11f. It is formed so as to cover the magnet 4. A certain amount of the adhesive is filled, and the surface is cured in a fillet shape. By confirming this surface shape, it can be estimated whether the magnet 4 is fixedly held at an appropriate position in the magnet housing portion 11f.

  The second shaft 12 is connected to the first shaft 11 to form the detection shaft 1 and is accommodated in the housing 2 (second housing 22). For example, a metal material is used for the second shaft 12. As with the first shaft 11, the second shaft 12 is preferably made of a non-magnetic material. However, when the degree of influence on the magnetic field from the magnet 4 to the magnetic detection element 5 is low, the second shaft 12 is made of a soft magnetic material such as steel. It is also possible to select a material as appropriate in light of cost and strength.

  The second shaft 12 includes a large-diameter portion 12a having three different diameters, a mid-diameter portion 12b, and a small-diameter portion 12c. The small diameter portion 12c is formed with a male screw portion 12d, and a step is formed between the male screw portion 12d and the diameter middle portion 12b. The second shaft 12 and the first shaft 11 are connected by the male screw portion 12d and the female screw portion 11e of the first shaft 11. When connecting, use a reinforcing adhesive to prevent the screws from loosening.

  The diameter middle portion 12b is formed in a cylindrical shape having a predetermined axial length, and is mounted with pistons 31 and 31 and a spring 32 of the origin return mechanism 3 described later.

  The large-diameter portion 12a is configured to be engaged with a piston 31 of an origin return mechanism 3 described later, and is opposed to the end surface of the first shaft 11 so as to sandwich the piston 31. The large-diameter portion 12a has, for example, a hexagonal shape around the outside, and can be rotated with a tool such as a wrench when connected to the first shaft 11.

  The housing 2 includes a first housing 21 in which the first shaft 11 is mainly accommodated, and a second housing 22 that is connected to the first housing 21 and in which the second shaft 12 is mainly accommodated.

  The first housing 21 is formed of a nonmagnetic material in a substantially cylindrical shape. For example, a metal material such as aluminum or stainless steel, or a synthetic resin material such as PBT (Poly Butylene Terephthalate) or PPS (Poly Phenylene Sulfide) is used. Used. A large diameter hole portion 21a, a diameter medium hole portion 21b, and a small diameter hole portion 21c are continuously formed in the inner peripheral portion of the first housing 21, and the medium diameter hole portion 21b and the small diameter hole portion 21c The first shaft 11 is slidably supported.

  In the large-diameter hole portion 21a, a female screw portion 21d is formed at an intermediate portion of the inner peripheral surface, and the second housing 22 is connected by a screw. The step between the large-diameter hole portion 21a and the medium-diameter hole portion 21b serves as a contact surface of the piston 31 of the origin return mechanism 3 described later.

  The diameter hole portion 21b is formed in a substantially D-shaped cross section that contacts the outer surface of the large diameter portion 11a of the first shaft 11, and in the axial direction, the first shaft 11 is detected by the detection stroke S of the first shaft 11. Even if it moves, it is formed to have a sufficient axial length.

  The small-diameter hole portion 21c is formed to have an inner diameter with which the middle diameter portion 12b of the first shaft 11 can slide. As a result, the rotation of the first shaft 11 around the central axis is restricted by the substantially D shape and the small-diameter hole portion 21c of the diameter medium hole portion 21b of the housing 2, and in the axial direction, the first shaft 11 slides for the detection stroke S. Is supported with high accuracy. Accordingly, the first shaft 11 is supported so as to be slidable with its overall length being restricted by the first housing 21.

  The first housing 21 is formed with a board holding part 21e of the circuit board 51 on which the magnetic detection element 5 is mounted corresponding to the position of the magnet housing part 11f (magnet 4) of the first shaft 11.

  The substrate holding part 21e is formed in a rectangular concave shape having a bottom surface. A screw hole for a screw for temporarily fixing the circuit board 51 is provided in the board holding part 21e. Moreover, the board | substrate holding | maintenance part 21e can fix the magnetic detection element 5 mounted in the circuit board 51 to the 1st housing 21 with a gap as small as possible with respect to the magnet 4, and can detect the change of the magnetic field by the magnet 4 with sufficient precision.

  The 2nd housing 22 is connected with the 1st housing 21, and the housing 2 is comprised, for example, a metal material is used. As with the first housing 21, the second housing 22 is preferably a non-magnetic material. However, since the distance from the magnet 4 is secured, the degree of influence on the magnetic field is not limited even if a soft magnetic material such as steel is used. It is low, and it is possible to select a material as appropriate in light of cost and strength.

  The second housing 22 is formed in a substantially two-stage cylindrical shape, and includes a large-diameter portion 22a and a small-diameter portion 22b.

  A male screw 22c is formed on the outer periphery of the intermediate portion of the large diameter portion 22a, and can be connected to the female screw portion 21d of the first housing 21 by being tightened at a predetermined position.

  A space for accommodating the pistons 31 and 31 and the spring 32 of the origin return mechanism 3 is provided on the inner peripheral side of the large diameter portion 22a. Further, the step formed on the inner periphery of the large diameter portion 22a becomes the contact surface of the piston 31 of the origin return mechanism 3 described later.

  The origin return mechanism 3 includes a pair of pistons 31 and 31 and a spring 32 that is mounted between the pistons 31 and 31 and biases them away from each other.

  For example, a metal material is used for the two pistons 31, 31. The non-magnetic material is preferable for the two pistons 31 and 31. However, since the distance from the magnet 4 is ensured, even a soft magnetic material such as a steel material has a low influence on the magnetic field. It is possible to select a material as appropriate in light of the strength.

  The two pistons 31 and 31 are formed in a cylindrical shape with a bottom, and a mounting hole for mounting on the diameter middle portion 12b of the second shaft 12 is formed in the center of the bottom portion. The two pistons 31, 31 are opposed to each other with the bottom portion facing outward, and are slidably mounted on the diameter middle portion 12 b of the second shaft 12, and a spring 32 constituted by a coil spring is interposed between the two pistons 31, 31. Mounted on the second shaft 12.

  The two pistons 31 are disposed in a second housing 22 formed by connecting the first housing 21 and the second housing 22.

  As the spring 32, a coil spring made of stainless steel, for example, SUS304WPB can be applied. The spring 32 is preferably made of a non-magnetic metal. However, since the spring 32 has a distance from the magnet 4, even if it is a soft magnetic material (for example, SWB or SWC), the influence on the magnetic field is low. The material may be appropriately selected in light of the properties and strength. Moreover, since the two pistons 31 and 31 can be pressed against the step in the housing 2 by the spring 32 regardless of the position of the detection shaft 1, the two pistons 31 and 31 having a gap are provided. Can be held without vibration. For this reason, a constant operational feeling can be provided for the stroke of the detection shaft 1. Moreover, the detection accuracy by the magnetic detection element 5 can be stabilized by preventing the vibration of the two pistons 31, 31.

  The two pistons 31, 31 of the origin return mechanism 3 have the outer surface of the piston 31 (the outer surface of the bottom of the bottomed cylinder) in contact with the end surface of the large-diameter hole 21 a of the first housing 21 at the origin position O. The outer surface of one piston 31 (the outer surface of the bottom of the bottomed cylinder) is in contact with the step surface of the second housing 22, so that the separation distance is regulated. The separation distance (interval) between the cylindrical portions of the two pistons 31 in this state (origin position O) is the detection stroke S of the detection shaft 1.

  At the origin position O, the outer surface of the piston 31 (the outer surface of the bottom of the bottomed cylinder) abuts the end surface of the large-diameter portion 11a of the first shaft 11, and the outer surface (bottomed) of the other piston 31. The outer surface of the bottom of the cylinder) is in contact with the end surface on the first shaft 11 side of the large diameter portion 12a of the second shaft 12.

  In the origin return mechanism 3, when the detection shaft 1 at the origin position O is displaced so as to be pushed into the housing 2, the outer surface of the piston 31 (of the bottomed cylinder) is inserted through the end surface of the large-diameter portion 11 a of the first shaft 11. Detection until the other piston 31 comes into contact with the stepped surface of the second housing 22 and cannot move and the cylindrical portions of the two pistons 31 and 31 hit against the spring 32 It can move by stroke S. When the force for pushing the detection shaft 1 disappears, the detection shaft 1 is returned to the origin position O by the spring force accumulated in the spring 32.

  In the origin return mechanism 3, when the detection shaft 1 at the origin position O is displaced so as to be pulled out from the housing 2, the outer surface of the piston 31 (the outer surface of the bottom of the bottomed cylinder) is the diameter of the second shaft 12. Pulled out through the end surface of the large portion 12a on the first shaft 11 side, the outer surface of the piston 31 (the outer surface of the bottom of the bottomed cylinder) can move in contact with the end surface of the large-diameter hole portion 21a of the first housing 21. Instead, it can move by the detection stroke S until the cylindrical portions of the two pistons 31, 31 hit against the spring 32. When the force for pulling out the detection shaft 1 is lost, the detection shaft 1 is returned to the origin position O by the spring force accumulated in the spring 32. Note that a lubricant such as grease is applied to the outer peripheral surface of the space in which the pistons 31 are accommodated, and ensures a long-term stable sliding with respect to the second shaft 12.

  The magnet 4 is composed of a rare earth magnet (for example, a magnet made of a material such as SmCo or NdFeB) formed in a quadrangular prism shape or a cylindrical shape. In this embodiment, the magnet 4 has a cylindrical shape using an SmCo sintered magnet, and two poles are magnetized in the major axis direction (magnet thickness direction). The magnet 4 is accommodated in the magnet accommodating portion 11f of the first shaft 11 of the detection shaft 1, and is fixed with an adhesive or the like.

  The magnet 4 provides a magnetic field to the magnetic detection element 5 facing the magnet 4 of the first housing 21, and the direction (magnetic force) of the magnetic field applied to the magnetic detection element 5 when the magnet 4 is displaced together with the detection shaft 1. As a result, the magnetic detection element 5 detects the amount of movement. The magnet 4 may be either a sintered magnet or a plastic magnet compressed or molded by mixing with plastic according to a manufacturing method. The sintered magnet has a stronger magnetic force, while the plastic magnet has characteristics such as higher mass productivity and higher crack resistance. Therefore, the sintered magnet may be appropriately selected according to use conditions and design requirements.

  The magnetic detection element 5 detects a displacement such as the amount of movement of the detected object. For example, the magnetic detection element 5 includes a Hall element and converts a change in magnetic force associated with the displacement such as the movement of the detected object into an electric signal. Output to the outside. For example, the magnetic detection element 5 is configured as a magnetic detection package in which a plurality of Hall elements are mounted on the circuit board 51.

  Here, as shown in FIG. 3, the detection surface of the magnetic detection element 5 is arranged in a direction perpendicular to the magnetization direction of the magnet 4. The magnetic detection package including the magnetic detection element 5 is surface-mounted on the circuit board 51, and the circuit board 51 is accommodated in the board holding portion 21e of the housing 2 (first housing 21), temporarily fixed with screws, and then filled. The member (potting agent) 52 is kept airtight. The magnetic detection element 5 is arranged so that the gap with the magnet 4 can be made as small as possible to detect a change in the magnetic field with high accuracy.

  Power supply to the magnetic detection element 5 and output to the outside are performed by a wiring (wiring code) 53. On one end side of the wiring 53, the copper wire is exposed from the coating, and protrudes from the through hole of the circuit board 51 to the mounting surface side of the magnetic detection element 5. This copper wire is connected to the circuit board 51 by soldering to the land around the through hole on the mounting surface side, and further connected to the magnetic detection element 5 via the copper foil pattern on the circuit board 51. The

  The concave substrate holding portion 21e is formed in a stepped shape having a bottom portion 21f that faces the magnetic detection element 5 and a concave portion 21g that corresponds to the solder connection portion and is deeper than the bottom portion 21f. .

  The bottom 21f is a smooth surface provided between the magnetic detection element 5 and the magnet 4, and in this case, the bottom 21f is designed to be positioned with a slight clearance from the magnetic detection element 5. Further, a boss (not shown) is formed from the bottom 21f, and a screw hole is formed so that the circuit board 51 can be screwed.

  The recess 21g is formed by digging down to a sufficient depth so as not to contact the tip of the wiring 53. By providing the recess 21g, the magnetic detection element 5 can be disposed closer to the magnet 4 side without the wiring 53 being in contact with the first housing 21 made of metal.

  The circuit board 51 is formed with a plurality of notches 51a at positions facing the bottom 21f and a plurality of notches 51b at positions facing the recess 21g. The notches 51a and 51b can act as a filling port and a deaeration port of the filling member 52, and are provided for each of the bottom 21f and the recess 21g having different depths. It can be done easily.

  The detection of the detection stroke S in the magnetic detection package using the magnetic detection element 5 is performed by using a plurality of Hall elements of the circuit board 51 and a horizontal magnetic field perpendicular to the magnetic detection surface of the magnetic detection element 5 of the magnetic field formed by the magnet 4. Detect the direction magnetic field. The obtained vertical magnetic field and horizontal magnetic field are converted into angles by a trigonometric function (ATAN) in a processing circuit (for example, ASIC: Application Specific Integrated Circuit) and output as angle information. The output angle information and the movement amount (detection stroke S) of the detection shaft 1 are proportional, and as a result, the movement amount of the detection shaft 1 can be detected.

  The output method from the magnetic detection package including the magnetic detection element 5 may be any method, and may be selected according to an electronic control unit (ECU) using the detection result (for example, analog). PWM (pulse width modulation control), SENT (Single Edge Nibble Transmission), etc.).

According to such a stroke sensor A,
A stroke sensor A that has a magnet 4 and detects the amount of movement of the detection shaft 1 that reciprocates around the origin position O following the object to be detected by the magnetic detection element 5 and restricts the rotation of the detection shaft 1. A housing 2 made of a non-magnetic metal material that is slidably supported, a circuit board 51 on which the magnetic detection element 5 is surface-mounted, and a housing on which the magnetic detection element 5 of the circuit board 51 is mounted. 2, a wiring 53 routed outside the housing 2, a concave substrate holding part 21 e that accommodates the circuit board 51 outside the housing 2, a filling member 52 that fills the board holding part 21 e and covers the circuit board 51, The substrate holding part 21e is provided with a step shape at a location facing the surface of the circuit board 51.

  Accordingly, since the substrate holding portion 21e is provided with a sufficient distance from the wiring 53 while the magnetic detection element 5 and the magnet 4 are sufficiently close to each other, a stroke that can efficiently arrange the circuit board 51 on which the magnetic detection element 5 is mounted. It becomes sensor A.

  In addition, the circuit board 51 is screwed and held in the board holding portion 21e so that the connection portion of the magnetic detection element 5 and the wiring 53 is not in contact with the housing 2, so that the airtight state by the filling member 52 is maintained. And short circuit between the wirings 53 can be prevented.

  The substrate holding portion 21e has a bottom portion 21f that faces the magnetic detection element 5, and a concave portion 21g that faces a connection portion of the wiring 53 provided outside the magnetic detection element 5 and is dug deeper than the bottom portion 21f. Accordingly, the circuit board 51 on which the magnetic detection element 5 and the wiring 53 are mounted can be efficiently arranged in the board holding portion 21e. Since the capacity | capacitance of the board | substrate holding | maintenance part 21e can also be made small, the filling amount of the filling member 52 is also suppressed.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the 1st Embodiment mentioned above, or an equivalent location, and the detailed description is abbreviate | omitted.

  The stroke sensor B according to the second embodiment is different from the first embodiment described above in that a pair of concave portions 21g are provided symmetrically to the substrate holding portion 21e. FIG. 4 is a cross-sectional view of the stroke sensor B. FIG. 5 is a view showing the substrate holding part 21e before the circuit board 51 is arranged in the stroke sensor B shown in FIG. 4, FIG. 5 (a) is a front view, and FIG. 5 (b) is a sectional view ( ZZ sectional view).

  The substrate holding part 21e has a bottom part 21f facing the magnetic detection element 5, a pair of recesses 21g dug deeper than the bottom part 21f, and a pair of bosses 21h protruding higher than the bottom part 21f. It is formed in a step shape.

  The bottom 21f is a smooth surface provided between the magnetic detection element 5 and the magnet 4, and in this case, the bottom 21f is designed to be positioned with a slight clearance from the magnetic detection element 5. The bottom portion 21f is formed in a rectangular shape at the center of the bottom surface of the substrate holding portion 21e.

  The pair of recesses 21 g is formed by digging down to a sufficient depth so as not to contact the tip of the wiring 53. The pair of recesses 21g are provided so as to face the short direction of the stroke sensor B across the bottom 21f. Each of the pair of recesses 21g is provided so as to be symmetric with respect to the center axis AX in the longitudinal direction of the stroke sensor B. Further, one of the pair of recesses 21 g opposes a connection portion of the wiring 53 provided outside the magnetic detection element 5. In FIG. 4, the concave portion 21 g 2 on the right side in the drawing faces the connection location of the wiring 53 on the circuit board 51. By providing the recess 21g, the magnetic detection element 5 can be disposed closer to the magnet 4 side without the wiring 53 being in contact with the first housing 21 made of metal. The operation and effect obtained by providing a pair of the recesses 21g so as to be symmetrical with each other will be described later.

  The pair of bosses 21 h are provided so as to protrude higher than the bottom portion 21 f in order to ensure a clearance between the bottom portion 21 f and the magnetic detection element 5. The pair of bosses 21h are provided so as to face the longitudinal direction of the stroke sensor B across the bottom 21f. Each of the pair of bosses 21h is provided in a symmetrical shape with respect to the central axis AX. Each of the pair of bosses 21h is formed with a screw hole 21i so that the circuit board 51 can be screwed. The screw hole 21i is formed by cutting. In addition to making the boss 21h symmetrical, a pair of bosses 21h may be provided symmetrically with respect to the central axis AX, and a screw hole 21i may be formed in one boss 21h by cutting according to the direction in which the wiring 53 is drawn. . In this case, two pairs (four in total) of the bosses 21h are provided.

  Further, a cutout portion 21j for routing the wiring 53 to the outside of the substrate holding portion 21e is formed on the side wall of the substrate holding portion 21e. That is, the wiring 53 is drawn out in the direction in which the notch 21j is formed. In FIG. 4, a notch 21j is formed in the left side wall of the substrate holding part 21e, and the wiring 53 is drawn out to the left. The notch 21j is formed by cutting.

  In a vehicle-mounted stroke sensor, the direction in which the wiring 53 is drawn may differ depending on the type of vehicle installed. Specifically, there are cases where the direction is the left direction and right direction in FIG. If the drawing direction of the wiring 53 is different, the circuit board 51 is also rotated by 180 ° along with this, so that the step shape of the board holding portion 21e needs to correspond to this. On the other hand, it is not desirable to prepare a dedicated mold for molding the first housing 21 in accordance with the direction in which the wiring 53 is drawn out because the manufacturing cost is high.

  Therefore, in the stroke sensor B according to the second embodiment, the pair of recesses 21g are provided symmetrically to the substrate holding part 21e. As a result, even when the drawing direction of the wiring 53 is changed to the facing side, one of the pair of recesses 21g faces the connection position of the wiring 53 on the circuit board 51, so that the tip of the wiring 53 is a metal. The magnetic detection element 5 can be arranged closer to the magnet 4 side without contacting the first housing 21 made of the above. That is, it is possible to cope with specifications in which the drawing direction of the wiring 53 is different with the same mold, and an increase in manufacturing cost can be suppressed.

  As a manufacturing process of the first housing 21, the first housing 21 including the substrate holding portion 21 e is formed by die molding, and then the screw hole 21 i and the notch portion are formed by cutting at a position corresponding to the drawing direction of the wiring 53. 21j is formed.

  FIG. 6 is a cross-sectional view of the stroke sensor B when the drawing direction of the wiring 53 is changed to the facing side. FIG. 7 is a front view showing the board holding portion 21e before the circuit board 51 is arranged in the stroke sensor B shown in FIG.

  In FIG. 6, the lead-out direction of the wiring 53 is changed from the left direction to the right direction. In this case, the left concave portion 21g1 of the pair of concave portions 21g faces the connection portion of the wiring 53 on the circuit board 51. By providing the recess 21g, the magnetic detection element 5 can be disposed closer to the magnet 4 side without the wiring 53 being in contact with the first housing 21 made of metal. Further, as shown in FIG. 7, the screw hole 21i is formed by cutting at a position inverted from the position before change (shown in FIG. 5A) with respect to the central axis AX. The notch portion 21j is formed by cutting on the right side wall of the substrate holding portion 21e. Since the screw hole 21i and the notch 21j that need to be changed are formed by cutting, an increase in manufacturing cost due to a change in the drawing direction of the wiring 53 can be suppressed.

According to such a stroke sensor B,
The substrate holding part 21e has a bottom part 21f facing the magnetic detection element 5 and a pair of recesses 21g dug deeper than the bottom part 21f. Each of the pair of recesses 21g is provided symmetrically to each other. Since one of the recesses 21g faces the connection location of the wiring 53 provided outside the magnetic detection element 5, it is possible to suppress the increase in manufacturing cost and satisfy the specifications in which the drawing direction of the wiring 53 is different.

  Further, the substrate holding part 21e has a boss 21h protruding higher than the bottom part 21f, the boss 21h has a symmetrical shape, and the screw hole 21i is formed in the boss 21h by cutting. It is possible to satisfy the specifications in which the drawing direction of the wiring 53 is different while suppressing an increase in manufacturing cost.

  Further, a cutout portion 21j for routing the wiring 53 to the outside of the substrate holding portion 21e is formed on the side wall of the substrate holding portion 21e by cutting, so that an increase in manufacturing cost can be suppressed and the drawing direction of the wiring 53 can be suppressed. Different specifications can be satisfied.

  Although the stroke sensor of the present invention has been described as an example in the configuration of the above-described embodiment, the present invention is not limited to this, and other configurations do not depart from the gist of the present invention. It goes without saying that various improvements and display changes can be made in the range. For example, regarding the screwing relationship between the housings 2 and the detection shafts 1, the relationship between the male screw and the female screw may be different from the embodiment described above.

  The present invention relates to a stroke sensor, and is suitable as a stroke sensor that is mounted on a vehicle that vibrates due to traveling or the like and detects the amount of movement of a movable component mounted on the vehicle.

DESCRIPTION OF SYMBOLS 1 Detection shaft 11 1st shaft 11a Large diameter part 11b Medium diameter part 11c Small diameter part 11d Male thread part 11e Female thread part 11f Magnet accommodating part 12 Second shaft 12a Large diameter part 12b Small diameter part 12c Small diameter part 12d Male thread 2 Housing 21 1st Housing 21a Large-diameter hole portion 21b Medium-diameter hole portion 21c Small-diameter hole portion 21d Female screw portion 21e Substrate holding portion 21f Bottom portion 21g Recessed portion 21h Boss 21i Screw hole 21j Notch portion 22 Second housing 22a Large-diameter portion 22b Small-diameter portion 22c Male screw 3 Origin Return mechanism 31 Piston 32 Spring 4 Magnet 5 Magnetic detection element 51 Circuit board 52 Filling member 53 Wiring A, B Stroke sensor O Origin position S Detection stroke

Claims (7)

A stroke sensor that has a magnet and detects the amount of movement of the detection shaft that reciprocates around the origin position following the object to be detected by a magnetic detection element,
A housing made of a non-magnetic metal material that slidably supports the rotation of the detection shaft; and
A circuit board for surface mounting the magnetic sensing element;
A wiring connected to the surface of the circuit board on which the magnetic detection element is mounted and routed out of the housing;
On the outside of the housing, a concave substrate holding portion that accommodates the circuit board;
A filling member that fills the substrate holding part and covers the circuit board;
With
The stroke sensor according to claim 1, wherein the substrate holding portion is provided with a step shape at a position facing the surface of the circuit board. 2. The stroke sensor according to claim 1, wherein the circuit board is screwed and held in the board holding portion so that a connection portion of the magnetic detection element and the wiring is not in contact with the housing. . The stroke sensor according to claim 1, wherein the circuit board has a plurality of notches. The substrate holding part, a bottom part facing the magnetic detection element;
2. The stroke sensor according to claim 1, wherein the stroke sensor has a concave portion that is opposed to a connection portion of the wiring provided outside the magnetic detection element and is dug deeper than the bottom portion. The substrate holding part has a bottom part facing the magnetic detection element, and a pair of concave parts dug deeper than the bottom part,
Each of the pair of recesses is provided symmetrically to each other,
2. The stroke sensor according to claim 1, wherein one of the pair of recesses faces a connection portion of the wiring provided outside the magnetic detection element. The substrate holding part has a boss protruding higher than the bottom part,
The boss has a symmetrical shape,
The stroke sensor according to claim 5, wherein a screw hole is formed in the boss by cutting. The stroke sensor according to claim 5 or 6, wherein a notch for routing the wiring to the outside of the substrate holding part is formed on a side wall of the substrate holding part by cutting.

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