JP2006170076A - Magnet switch for starter and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnet switch for a starter suppressing enlargement of a body in spite of adopting U-shaped yoke excellent in productivity. <P>SOLUTION: A pair of shaft plate part of the U-shaped yoke (frame) 11 forming a part of magnetic pass crossing an exciting coil 8 wound around a coil bobbin 9 is bent in an arc shape in a direction toward the coil bobbin. Consequently, the magnet switch for the starter and a starter equipped with the same can be miniaturized. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a starter magnet switch and a method of manufacturing the same.

A magnetic switch for a starter in which a yoke (sometimes referred to as a frame) is formed in a U shape is described in Patent Document 1 below. More specifically, as shown in FIG. 6, the U-shaped yoke has a radial plate portion (also referred to as a bottom plate portion) that extends radially while facing one end surface of the coil bobbin, and a radial direction of the radial plate portion. A pair of shaft plate portions (also referred to as leg plate portions) extending in the same direction in the axial direction while facing the outer peripheral surface of the coil bobbin from both ends, and a stationary magnetism linked to an excitation coil wound around the coil bobbin It constitutes a part of the road. This U-shaped yoke can be configured by simple processing of a flat plate-shaped mild steel plate, so it is manufactured for a yoke configured by press-fitting a ring-shaped yoke at one axial end of a conventional cylindrical yoke. Has the advantage of being easy.
Japanese Patent Laid-Open No. 5-190070

  However, the starter magnet switch having the U-shaped yoke described above is a direction in which both shaft plates of the U-shaped yoke are connected in the radial cross section with respect to the starter magnet switch having the cylindrical yoke with the bottom described above. Therefore, there is a problem in that the radial cross-sectional shape of the magnet switch is not a circular shape with which the minimum cross-sectional area can be obtained, but is irregular, and the yoke size, that is, the static magnetic path size is increased.

  The reason for the increase in the size of the U-shaped yoke will be further described.

  First, although the radial cross section of the exciting coil wound around the coil bobbin is a circular cross section, the pair of shaft plates of the U-shaped yoke are substantially tangent to the outer peripheral surface of the exciting coil in the radial cross section. Since it extends in the direction, a useless gap is generated between the outer peripheral surface of the exciting coil and the shaft plate portion.

  Next, the fact that the shaft plate portion is separated from the outer peripheral surface of the exciting coil in this way means that the average magnetic path length of the diameter plate portion that causes the magnetic flux to flow from the shaft plate portion to the radial center increases accordingly. Therefore, it is necessary to increase the thickness of the diameter plate portion in order to prevent an increase in the magnetic resistance of the static magnetic path.

  Furthermore, the rigidity of the shaft plate portion is insufficient when the plate as the stationary radial magnetic path member located at the tip of the shaft plate portion and extending in the radial direction is caulked and fixed to the case containing the U-shaped yoke. Therefore, it is necessary to take measures against the problem that the plate leg portion is deformed.

  In addition, the increase in the size of the U-shaped yoke described above increases the size of other members, such as contact covers, of the starter magnet switch having the U-shaped yoke, and also fixes the enlarged starter magnet switch. In addition, an increase in the necessary space for housing was invited.

  The present invention has been made in view of the above problems, and an object thereof is to provide a starter magnet switch capable of suppressing an increase in physique even though a U-shaped yoke excellent in manufacturability is employed.

  The first invention made to achieve the above object is to face the outer peripheral surface of the coil bobbin from the radial plate portion extending in the radial direction while facing one end surface of the coil bobbin, and from both radial ends of the radial plate portion. A magnet for a starter having a pair of shaft plates extending substantially in the same axial direction and having a U-shaped yoke forming a part of a magnetic path interlinking with the exciting coil wound around the coil bobbin In the switch, the pair of shaft plates are curved in a direction surrounding the coil bobbin. In addition, the axial direction substantially same direction said here shall mean the angle range of 0-30 degrees.

  In this way, it is possible to provide a starter magnet switch that can suppress an increase in physique despite the adoption of a U-shaped yoke having excellent manufacturability. More specifically, in the present invention, since the pair of shaft plates of the conventional U-shaped yoke are curved in an arc shape in the radial cross section, they are arranged at a small interval on the circular outer peripheral surface of the exciting coil. Therefore, it is possible to reduce the size of the magnet switch by reducing a useless gap between the outer peripheral surface of the exciting coil and the shaft plate portion. In addition, the average radial direction length, that is, the average magnetic path length of the diameter plate portion of the yoke can be shortened by the amount that the shaft plate portion of the yoke can be disposed close to the outer peripheral surface of the excitation coil. The thickness of the plate portion can be reduced, and as a result, the physique of the magnet switch can be reduced.

  Further, since the rigidity of the shaft plate portion of the yoke can be increased, the shape stability against the external force in the radial direction to the magnet switch can be improved, and the necessary space for the starter magnet switch can be reduced.

  In a preferred embodiment, the coil bobbin faces the other end surface of the coil bobbin, extends in the radial direction, forms part of a magnetic path interlinked with the excitation coil wound around the coil bobbin, and has a locking groove on the outer periphery. And a bottom portion facing the plate, and a cylindrical portion fitted to the U-shaped yoke, and an outer peripheral portion of the bottom portion is axially positioned at a position facing the locking groove portion. A switch case having a locking hole, and a shaft plate portion of the U-shaped yoke extends axially through the locking groove portion of the plate, It has a protrusion for locking that reaches the hole and is plastically deformed and locked to the plate and the switch case.

  In this way, the shaft plate portion of the yoke can be easily and securely fixed to the plate and the switch case, and the shaft plate portion of the yoke and the plate can be magnetically coupled.

  In a preferred aspect, a plurality of the locking projections are formed on each of the pair of shaft plate portions. Thereby, the coupling between the yoke and the plate can be strengthened, and the magnetic resistance can be reduced.

  In a preferred aspect, the locking projections are respectively formed at both ends in the circumferential direction of the distal end portion of the shaft plate portion. Thereby, the adhesiveness between the shaft plate portion and the plate in the circumferential direction of the switch, that is, the substantially width direction of the shaft plate portion can be improved, and the magnetic resistance can be further reduced.

  In a preferred aspect, the pair of shaft plates face each other across a plane including the axis of the starter magnet switch and the axis of the starter motor adjacent to the starter magnet switch. If it does in this way, the apparatus dimension (height in one example) in the direction which connects both the above-mentioned axial centers can be reduced. Further, since the distance between the motor shaft center and the switch shaft center can be shortened, the required length of the lever can be shortened.

  In a preferred aspect, the locking projections have claw portions that can be plastically deformed in the circumferential direction on both sides in the circumferential direction, and the locking projections formed on one of the pair of shaft plates. The locking projections formed on the other of the pair of shaft plate portions are arranged at substantially point-symmetrical positions, and are substantially point-symmetrical positions selected from all pairs of the locking projections. Locking processing for simultaneously plastically deforming the pair of locking protrusions is performed sequentially for each pair. As a result, the deformation force can be reduced by temporally dividing the deformation force on the shaft plate portion of the yoke in the plastic deformation, and the force for plastic deformation can be applied to the pair of shaft plate portions at symmetrical positions. Therefore, the frame does not tilt with respect to the solenoid axis.

  A second invention made to achieve the above object is applied to a starter having a switch shaft different from that of an output shaft, facing a first end surface of a coil bobbin and extending in a radial direction, A pair of shaft plates extending in the same direction in the axial direction while facing the outer peripheral surface of the coil bobbin from both ends in the radial direction, and a part of the magnetic path interlinking with the excitation coil wound around the coil bobbin A starter magnet switch having a U-shaped yoke, wherein the pair of shaft plates includes an axis of the starter magnet switch and an axis of a starter motor adjacent to the starter magnet switch. It is characterized by facing each other across a virtual plane. In this way, as described above, effects such as the reduction in the size of the starter can be achieved.

  A preferred embodiment of a starter magnet switch of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments, and it is a matter of course that the technical idea of the present invention can be configured by combining other known techniques or other techniques having the same functions as those of other known techniques.

(Example)
The starter magnet switch of this embodiment is a device that is integrally fixed to a starter (not shown) and controls the power supply to the starter motor intermittently and also drives a pinion drive lever. Except for the conventional lever-driven starter magnet switch, the essential structure and operation are the same.

(Description of overall configuration)
An axial sectional view of this starter magnet switch is shown in FIG.

  The starter magnet switch includes a switch main body 1 that is a composite device in which main members other than the contact members are accommodated, and a plunger shaft 2 that protrudes rearward from the rear end face of the switch main body 1 and moves linearly in the axial direction. A switch main body portion having a movable contact member 3 fixed to the distal end portion and extending in a substantially radial direction of the plunger shaft 2 and a recess (also referred to as a contact chamber) 4 for accommodating the movable contact member 3 so as to be axially displaceable. 1 includes a resin-made contact cover 5 that is fixed to a rear end surface of the contact cover 5 with a packing, and a pair of bolt-shaped fixed contact members 6 and 7 that are fixed to the bottom of the contact cover 5.

(Description of switch body 1)
The switch body 1 will be described. The switch body 1 has an exciting coil 8. The exciting coil 8 includes a suction coil and a holding coil wound around the bobbin 9 in two layers. A magnetic circuit is formed for passing the magnetic flux generated by energizing the exciting coil 8 in linkage with the exciting coil 8. The switch body 1 is housed in a switch case 10 having a cylindrical shape with a bottom and opening rearward.

  This magnetic circuit includes a bottomed cylindrical frame 11 that covers the outer periphery of the exciting coil 8, a stationary core 12 that is disposed in a direction that closes the opening of the frame 11 at the rear end of the switch body 1, and a so-called movable iron piece member. It is comprised by the plunger 13 and plate 130 which are. In this embodiment, the switch case 10 is made of mild steel so that a part of the magnetic flux can flow, but the switch case 10 may be made of resin.

  The plunger 13 is inserted into the inner periphery of the bobbin 9 via a cylindrical sleeve so as to be slidable in the axial direction. Reference numeral 14 denotes a return spring that is disposed between the stationary core 12 and the plunger 13 and biases the plunger 13 forward.

  The plunger 13 has a recess opening forward, and a lever driving rod 15 and a lever spring 16 for urging the lever driving rod 15 rearward are accommodated in the recess. The base end of the lever spring 16 is locked to a collar 17 that is locked to the front end of the plunger 13 so as to surround the recess, and the biasing end of the lever spring 16 attaches the rear end of the lever driving rod 15 to the rear. It is fast.

  The plunger shaft 2 is made of brass, for example, and protrudes rearward from the plunger 13 along the plunger axis through the stationary core 12 and enters the contact chamber 4. A bush 18 is fitted to the tip of the plunger shaft 2 so as to be movable in the axial direction, and the movable contact member 3 is fitted to the bush 18 and extends in the radial direction. The movable contact member 3 is urged rearward by a contact spring 19. A washer 20 as a stopper member for restricting the backward movement of the movable contact member 3 (movement toward the distal end side of the plunger shaft 2) is fixed to the distal end of the plunger shaft 2 by a circlip.

(Description of operation)
The operation of the starter magnet switch described above will be described. When the exciting coil 8 is energized by inserting an IG key (not shown), the plunger 13 is attracted and retracted from the initial position shown in FIG. The movable contact member 3 contacts the pair of fixed contact members 6 and 7. After the movable contact member 3 comes into contact with the fixed contact members 6 and 7, the plunger 13 further moves backward while pressing and contracting the contact spring 19, and comes into contact with the front end surface of the stationary core 12 to stop the backward movement of the plunger 13. The contact spring 19 applies a pressing force toward the fixed contact members 6 and 7 to the movable contact member 3. As a result, the magnet switch is closed and power is supplied from the battery to the starter motor. When the energization of the exciting coil 8 is turned off after the engine starts and the magnetic force disappears, the return spring 14 pushes the plunger 13 back to the original position. At this time, the movable contact member 3 is separated from the fixed contact members 6 and 7, and the magnet switch is cut off.

(Description of static magnetic circuit)
Of the magnetic circuit, a stationary magnetic circuit excluding the plunger 13, that is, a yoke (stationary yoke) is constituted by a frame 11, a stationary core 12 and a plate 130. The frame 11 is made of a U-shaped mild steel plate including a bottom plate portion 110 extending in the radial direction and a pair of leg plate portions 111 and 112 extending forward from both ends of the bottom plate portion 110 in the axial direction. Further details of the frame 11 will be described later. The stationary core 12 is a cylindrical member made of mild steel that is press-fitted into the central hole of the bottom plate portion 110 of the frame 11, and the plunger shaft 2 extends through the inside thereof so as to be axially movable. The plate 130 is a ring-shaped soft magnetic member whose both ends are locked to the front end portion of the frame 11 and extend radially inward, and the lever driving rod 15 is axially movable in the center hole thereof. It is penetrating.

(Description of frame 11)
The shape of the frame 11 is shown in FIG. 2A is a front view in the axial direction, FIG. 2B is a side view, and FIG. 2C is a plan view.

  As described above, the frame (U-shaped yoke) 11 has a bottom plate portion (also referred to as a diameter plate portion) 110 that extends in the radial direction, and extends axially forward from both ends of the bottom plate portion 110. It consists of a U-shaped mild steel plate consisting of a pair of leg plate portions (also called shaft plate portions) 111 and 112.

  The bottom plate portion 110 has a substantially rectangular flat plate shape extending in the radial direction while facing the rear end surface of the bobbin 9, and has a hole 113 into which the stationary core 12 is fitted at the position of the plunger shaft center. ing. The leg plate portions 111 and 112 have an arc shape extending in the axial direction while curving in an arc shape so as to surround the exciting coil 8 from the left and right ends of the bottom plate portion 110. At the front ends of the leg plate portions 111 and 112, a claw-like convex portion (locking protrusion) 114 is provided so as to protrude from the center in the vertical direction. The frame 11 can be easily formed by press-punching a mild steel plate including the hole 113 and then forming it into an arc shape while bending the leg plate portions 111 and 112.

(Description of fixing the frame 11 and the plate 130)
The mechanical coupling between the frame 11 and the plate 130 will be described with reference to FIG. FIG. 3 is an enlarged cross-sectional view showing the vicinity of the convex portion 114 of the frame 11.

  A locking groove 131 is provided at the radially outer end of the plate 130. The switch case 10 includes a bottom plate portion 101 and a peripheral wall portion 102, and a through-hole (locking hole portion) 103 communicating with the groove portion 131 of the plate 130 is provided on the outer peripheral portion of the bottom plate portion 101. As shown in FIG. 3, the through-hole 103 is narrow on the back side adjacent to the groove 131 of the plate 130 and is wide on the front side.

  The convex portion 114 passes through the groove portion 131 of the plate 130 and is fitted into the through hole 101 in front thereof. A pair of cuts extending rearward in the axial direction are provided at the tip of the convex part 114, and the convex part 114 is locked to the switch case 10 and the plate 130 by expanding the cut.

(Example effect)
If it does in this way, the effect mentioned above can be produced.

(Modification)
Another preferred shape of the frame 11 will be described with reference to FIG. 2A is a front view in the axial direction, FIG. 2B is a side sectional view, and FIG. 2C is a plan view. In this modification, convex portions 114 are provided at both upper and lower ends of the leg plate portions 111 and 112, respectively. Therefore, the frame 11 has two pairs of convex portions 114 arranged at point-symmetrical positions.

  In addition, the operation | work which pushes and expands the convex part 114 to a nail | claw shape does not perform these two pairs of convex parts 114 simultaneously, but performs one pair at a time. Naturally, the two convex portions 114 that are point-symmetric with respect to each other are processed simultaneously. In this way, the undesired asymmetric torsional force with respect to the frame (yoke) 11 and the switch case 10 can be reduced by the above-described plastic deformation that spreads, and the frame 11 is greatly inclined with respect to the plunger axis. Can be deterred.

  Moreover, according to this aspect, since many convex parts 114 were provided, the locking force required for the coupling | bonding with the frame 11, the plate 130, and the switch case 10 can be disperse | distributed, and a locking process is made easy. You can also. Furthermore, since the convex part 114 is arrange | positioned at the circumferential direction both ends of the leg-plate parts 111 and 112, the improvement of the magnetic or mechanical connection of the flame | frame 11 and the plate 130 can be aimed at.

(Magnet switch placement)
The arrangement of the starter magnet switch of the above-described embodiment will be described with reference to FIG. FIG. 5 is a schematic front view of the arrangement of the starter magnet switch and the starter motor as viewed in the radial direction. In FIG. 5, the left half shows the conventional arrangement, and the right half shows the arrangement of this embodiment. As is clear from FIG. 5, in the starter magnet switch of this embodiment, the pair of leg plate portions 111 and 112 of the frame 11 are arranged on the left and right sides. Can be made shorter than the distance L ′ in a conventional starter having a cylindrical frame. As a result, it is possible to achieve practically significant effects such as a reduction in the size and weight of the lever, a reduction in the size of the starter, and a reduction in the space for accommodating the starter. Furthermore, since the switch shaft is different from the output shaft, the external dimensions of the switch are severe to interference with engine-side components, so that there is an advantage that the distance between the starter shaft center and the motor shaft center can be shortened.

It is sectional drawing of the axial direction of the magnet switch for starters of an Example. It is a figure which shows the shape of the flame | frame of FIG. 1, (a) is the front view seen to the axial direction, (b) is a side view, (c) is a top view. It is an expanded sectional view showing the convex part neighborhood of a frame. It is a figure which shows the shape of the flame | frame of a deformation | transformation aspect, (a) is the front view seen to the axial direction, (b) is a side view, (c) is a top view. It is the model front view seen from the radial direction which shows arrangement | positioning with the magnet switch for starters, and a starter motor. It is a figure which shows the shape of the conventional frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Switch main-body part 2 Plunger axis | shaft 3 Movable contact member 4 Contact chamber 5 Contact cover 6 Fixed contact member 7 Fixed contact member 8 Excitation coil 9 Bobbin 10 Switch case 11 Frame (U-shaped yoke)
12 Stationary Core 13 Plunger 14 Return Spring 15 Lever Drive Rod 16 Lever Spring 17 Collar 18 Bush 19 Contact Spring 20 Washer 101 Bottom Plate 102 Peripheral Wall 103 Through-hole (Locking Hole)
110 Bottom plate (diameter plate)
111 Leg plate (shaft plate)
112 Leg plate (shaft plate)
113 hole 114 convex portion (protruding portion for locking)
130 Plate 131 Groove (Locking groove)

Claims (7)

A diameter plate portion extending in the radial direction while facing one end surface of the coil bobbin, and a pair of shaft plates extending in substantially the same axial direction while facing the outer peripheral surface of the coil bobbin from both radial ends of the diameter plate portion A starter magnet switch having a U-shaped yoke forming a part of a magnetic path interlinking with an exciting coil wound around the coil bobbin,
The starter magnet switch according to claim 1, wherein the pair of shaft plates are curved in a direction surrounding the coil bobbin. The starter magnet switch according to claim 1,
A plate having a locking groove on the outer periphery, forming a part of a magnetic path extending in a radial direction while facing the other end surface of the coil bobbin and interlinking with an excitation coil wound around the coil bobbin;
A bottom portion facing the plate and a cylindrical portion fitted to the U-shaped yoke, and an outer peripheral portion of the bottom portion is used for locking in the axial direction at a position facing the locking groove portion. A switch case having a hole;
Have
A shaft plate portion of the U-shaped yoke extends through the locking groove portion of the plate in the axial direction to reach the hole of the switch case, and is plastically deformed to be engaged with the plate and the switch case. A starter magnet switch having a locking projection to be stopped. The starter magnet switch according to claim 2,
The starter magnet switch according to claim 1, wherein a plurality of the locking protrusions are formed on each of the pair of shaft plates. The starter magnet switch according to claim 3,
2. The starter magnet switch according to claim 1, wherein the locking protrusions are formed at both ends in the circumferential direction of the tip of the shaft plate. The starter magnet switch according to any one of claims 1 to 4,
The pair of shaft plates are
A starter magnet switch characterized by facing a virtual plane including an axis of the starter magnet switch and an axis of a starter motor adjacent to the starter magnet switch. In the manufacturing method of the magnet switch for starters in any one of Claims 2 thru | or 5,
The locking protrusion has claw portions that can be plastically deformed in the circumferential direction on both sides in the circumferential direction,
The locking projection formed on one of the pair of shaft plate portions and the locking projection formed on the other of the pair of shaft plate portions are arranged at substantially point-symmetrical positions,
A locking process for simultaneously plastically deforming the pair of locking protrusions at the substantially point-symmetrical positions selected from all pairs of the locking protrusions is performed sequentially for each pair. To manufacture a magnetic switch for starter. The switch shaft is used in a different type of starter from the output shaft, and faces the outer surface of the coil bobbin from the radial plate portion that extends in the radial direction while facing one end surface of the coil bobbin. A magnet switch for a starter having a pair of shaft plates extending in the same direction in the axial direction and having a U-shaped yoke that forms part of a magnetic path interlinking with the excitation coil wound around the coil bobbin Because
The pair of shaft plate portions is the pair of shaft plate portions,
A starter magnet switch characterized by facing a virtual plane including an axis of the starter magnet switch and an axis of a starter motor adjacent to the starter magnet switch.

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