ROTARY SWITCH DEVICE

Abstract

A rotary switch device includes a terminal base to which a center portion contact and a fixed contact member are fixed, a movable contact member, and a support portion. The movable contact member includes a contact protrusion part which is pressed in contact with the center portion contact at one end of the movable contact member and a first contact surface which is in contact with the fixed contact member at another end of the movable contact member, and which is operated to rotate around the center portion contact so as to short-circuit between the center portion contact and the fixed contact member at a conductive rotation position.

Claims

1. A rotary switch device comprising: a terminal base to which a center portion contact and a fixed contact member are fixed; a movable contact member; and a support portion, wherein the movable contact member includes a contact protrusion part which is pressed in contact with the center portion contact at one end of the movable contact member and a first contact surface which is in contact with the fixed contact member at another end of the movable contact member, and which is operated to rotate around the center portion contact so as to short-circuit between the center portion contact and the fixed contact member at a conductive rotation position, wherein the support portion is formed in the terminal base and supports an edge corner portion along a rotation direction when the first contact surface of the movable contact member is operated to rotate, and wherein the movable contact member configured to slide on the support portion with the edge corner portion as a sliding contact portion and moves to the conductive rotation position in which the first contact surface is in contact with the fixed contact member.

2. The rotary switch device according to claim 1, wherein the support portion supports the movable contact member at a high position with respect to a plane of the fixed contact member, and in a supporting state, holds the movable contact member in a state that the movable contact member is rotatable in a direction perpendicular to the plane.

3. The rotary switch device according to claim 1, wherein the first contact surface of the movable contact member and a second contact surface of the fixed contact member are formed in rectangular shapes in which a contact point to the other moves from one end portion to another end portion in a predetermined connecting operation angle from a start of a contact of both the fixed contact member and the movable contact member, and the movable contact member uses the corner portion on a contact end point side as the sliding contact portion with the support portion.

4. The rotary switch device according to claim 3, wherein conductive processing for corrosion resistant is applied to the first contact surface of the movable contact member and the second contact surface of the fixed contact member.

5. The rotary switch device according to claim 1, further comprising: a plurality of movable contact members that moves on a same circular moving locus.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a sectional view illustrating a steering lock apparatus.

[0032] FIG. 2 is an exploded perspective view of an ignition switch.

[0033] FIG. 3 is a view illustrating an arrangement of fixed contacts.

[0034] FIG. 4 is a view illustrating a position of a movable contact member at a LOCK position.

[0035] FIG. 5A is a sectional view taken along line 5A-5A of FIG. 4 and FIG. 5B is an enlarged view of a main portion of FIG. 5A.

[0036] FIG. 6A is a plan view illustrating a state of an initial stage of contact to an ON position and FIG. 6B is a sectional view taken along line 6B-6B of FIG. 6A.

[0037] FIG. 7A is a plan view illustrating a position of the movable contact member at the ON position and FIG. 7B is a sectional view taken along line 7B-7B of FIG. 7A.

[0038] FIG. 8A is a side view illustrating the movable contact member and FIG. 8B is a view as viewed in a direction of arrow 8B of 8A.

[0039] FIG. 9 is a flowchart illustrating a conduction state of a contact of the ignition switch.

DETAILED DESCRIPTION

[0040] A rotary switch device of the present invention configured as an ignition switch used in a steering lock apparatus is illustrated in FIG. 1 and the following. The steering lock apparatus of the example includes a cylinder lock 10 accommodated in a housing 9 and a cam member 11 connected to a terminal of a plug 10a of the cylinder lock 10, and is fixed to a steering column (not illustrated).

[0041] The housing 9 is provided with a lock piece 12 which moves between a lock position which advances and retreats in a direction intersecting a rotation axis of the cam member 11 at a predetermined angle and protrudes into the steering column, and an unlock position which is accommodated in the housing 9. The lock piece 12 is urged to a direction of the lock position by a compression spring 13 and when the plug 10a of the cylinder lock 10 is operated to rotate from a lock rotation position, the lock piece 12 moves from the lock position where the lock piece 12 is locked to a steering shaft to the unlock position where the lock piece 12 is released, and the steering shaft can be operated.

[0042] In addition, the ignition switch is connected to the housing 9 to cause predetermined terminals to conduct in accordance with the rotation of the plug 10a and a power supply state to an electrical system of a vehicle to be changed. In order to transmit the rotational operation of the plug 10a to the ignition switch, a connecting bar 14 which meshes with the cam member 11 and rotates together with the cam member 11 is disposed in the housing 9.

[0043] As illustrated in FIG. 2, the ignition switch includes a switch case 15 having a terminal base 3 having a circular shape in plan view, a rotation movable portion 16 rotatable around a center of the terminal base 3 with respect to the switch case 15, and a switch cover 17 connected to the switch case 15 to cover the rotation movable portion 16. A center portion contact 1 and a fixed contact member 2 are disposed in the terminal base 3 formed by an insulating material in a state of being exposed to a rotation boundary surface with the rotation movable portion 16.

[0044] The center portion contact 1 and each fixed contact member 2 are drawn into the switch case 15 via wiring.

[0045] The rotation movable portion 16 is formed of an insulating material and connecting bar and a connecting hole 16a are formed at one end portion. The rotation movable portion 16 is urged only when returning from START position to ON position by a torsion spring 18, and moderately rotates at an appropriate connecting operation angle by fitting a click ball 20 urged by a click spring 19 into a groove of an inner wall of the switch cover 17.

[0046] Furthermore, a plate-like movable contact member 6 having a predetermined plate thickness is accommodated in the rotation movable portion 16 so that a plate thickness surface faces the terminal base 3. The movable contact member 6 includes a contact protrusion part 4 of a V-shaped protrusion at one end and a flat contact surface 5 at the other end, a rounded chamfer is formed at a tip of the contact protrusion part 4 in order to keep a good contact state when the movable contact member 6 is in pressure contact with the center portion contact 1 which is described later. As illustrated in FIG. 8B, the flat contact surface 5 in the movable contact member 6 is formed in a V shape so that the movable contact member 6 smoothly rides on the support portion 8 when the flat contact surface 5 in the movable contact member 6 moves back and forth between the fixed contact member 2 and the support portion 8.

[0047] As described above, the movable contact member 6 is formed in the V shape so that timing at which the movable contact member 6 is in contact with the fixed contact member 2 can be made earlier.

[0048] Three pieces of the movable contact members 6 formed as described above are used corresponding to the respective fixed contact members 2 which are described later.

[0049] As illustrated in FIG. 1, each movable contact member 6 is accommodated in an accommodation groove 16b formed in the rotation movable portion 16, is movable in a direction along the rotation axis (RA), and is urged to a surface side of the terminal base 3 by compressions springs 21 accommodated in the rotation movable portion 16 and pressing the contact protrusion part 4 and a back surface of the contact surface 5.

[0050] The ignition switch according to the example is formed to output a power supply voltage input from a power supply terminal to three output terminals of +IGN1, +IGN2, and START when the plug 10a is operated to rotate in the order of LOCK, ON, and START positions. FIG. 9 illustrates a power supply operation to each terminal and power is supplied in the order of the +IGN2 terminal and the +IGN1 terminal by the movement of the plug 10a from the LOCK position to the ON position. Thereafter, when the plug 10a is rotated to the START position, first, the power supply to the +IGN2 terminal is stopped, and then the power supply is started to the. START terminal in addition to the +IGN1 terminal where the power supply state is maintained.

[0051] The sequence described above is realized by short-circuiting the center portion contact 1 disposed at a center portion of the terminal base 3 and the fixed contact member 2 disposed around the center portion contact 1 and connected to the +IGN1 terminal, the +IGN2 terminal, and the START terminal by the movable contact member 6 described above.

[0052] If sliding loci of the movable contact members 6 in the center portion contact 1 overlap each other, a chance of wear at an overlapping portion increase. In order to prevent this, as illustrated by chain lines in FIG. 7A, the movable contact member 6 that is in contact with and disconnected from the +IGN1 terminal and the movable contact member 6 that is in contact with and disconnected from the +IGN2 terminal of which rotation ranges overlap each other move along arcs (AC1 and AC2) having different diameters on the center portion contact 1.

[0053] Silver plating as conductive processing for corrosion resistant is applied to the surfaces of the fixed contact member 2 and the movable contact member 6 in order to prevent occurrence of corrosion on the contact surface and enhance contact reliability without requiring a self-cleaning operation by a high contact pressure.

[0054] As illustrated in FIG. 3, the three fixed contact members 2 are respectively disposed at terminal positions of three support portions 8 formed in the terminal base 3. Each fixed contact member 2 is formed in a rectangular shape intersecting the support portion 8, the support portion 8 is disposed on two concentric circles with respect to the center of the terminal base 3, and as illustrated in FIG. 5B, is formed as a protrusion which is higher than the center portion contact 1 by H8. As illustrated in FIG. 6B, the fixed contact member 2 is disposed so that the surface thereof is higher than the center portion contact 1 by H2 and lower than the support portion 8.

[0055] Furthermore, the center portion contact 1, the fixed contact member 2, and the support portion 8 are formed in a floating island shape of which a periphery is surrounded by a recessed portion 22, and propagation of the abrasion powders between the fixed contact members 2, and between the support portion 8 and the fixed contact member 2, and coagulated powder of molten splashes due to the arc discharge is regulated.

[0056] The support portion 8 supports an opposite end of the movable contact member 6 with respect to the contact protrusion part 4 in a nonconductive state where the movable contact member 6 is not in contact with the fixed contact member 2, and functions as a traveling path when the movable contact member 6 is operated to rotate.

[0057] As illustrated in FIG. 5B, the support of the movable contact member 6 is carried out by placing the corner portion 7 on the contact protrusion part 4 of the contact surface 5 on the support portion 8, and in this state, the contact surface 5 is in a floating state and is prevented from being in contact with the support portion 8 during non-conduction and traveling.

[0058] When the movable contact member 6 is operated to rotate in the clockwise direction in FIG. 4 from this state, the movable contact member 6 travels on the support portion 8 with the contact portion of the support portion 8 as the sliding portion, and then rides on an inclined surface 8a formed at a terminal of the support portion 8. The inclined surface 8a is formed to gradually become a low back, the movable contact member 6 moved to the inclined surface 8a vertically rotates to a vicinity of a horizontal posture while reducing a vertical rotation angle (see : FIG. 5B), and lands on the fixed contact member 2 as illustrated in FIGS. 6(a) and 6(b).

[0059] In this state, the movable contact member 6 is in contact with a bent portion formed by bending an edge of one end portion of the fixed contact member 2 in a longitudinal direction. Furthermore, when the rotational operation with respect to the movable contact member 6 is continued, the contact point with the movable contact member 6 moves to a final contact position which is slight shifted in a direction in which a dimension (6) in FIGS. 6(b) and 7(b) increases in a width direction, that is, in a direction approaching a rotation center of the movable contact member 6 on the opposite end side in the longitudinal direction.

[0060] On the other hand, as illustrated in FIGS. 8(a) and 8(b), the contact point of the contact surface 5 of the movable contact member 6 with the fixed contact member 2 moves from a contact start point 6a to a final contact point 6b in a direction of the corner portion 7 side with the rotation of the movable contact member 6.

[0061] As a result, even in a case where the ignition switch of the example is used for the high current usage and the surface state is deteriorated due to the generation of the arc discharge at the contact start point, since the final contact position is located at a position away from the arc discharge position (contact start point), it is possible to reliably prevent contact failure.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

[0062] 1 center portion contact

[0063] 2 fixed contact member

[0064] 3 terminal base

[0065] 4 contact protrusion part

[0066] 5 contact surface

[0067] 6 movable contact member

[0068] 7 corner portion

[0069] 8 support portion