DIP switch

Abstract

To provide a dip switch which prevents occurrence of irreversible heat deformation of a contact terminal in mounting on a printed board, and can properly maintain a switch function of the contact terminal.SOLUTION: A dip switch has: a housing; an operation member which has a knob part accessible from outside the housing, and is held by the housing so as to freely transition between a first attitude and other attitude by operation of the knob part; one terminal which is held by the housing; other terminal which is held by the housing, and has a deformation part that is separated from the one terminal when a fixation part fixed to the housing and the operation member are in other attitudes, is deformed by being pressed when the operation member is in the one attitude, and thereby is brought into contact with the one terminal; and a thermo-sensitive element which is engaged with the operation member so that the attitude of the operation member is changed according to the deformation and is brought into contact with the fixation part of the other terminal, and is made of a shape memory alloy that exhibits such elasticity that the shape of the operation member is returned to the other attitude at a temperature higher than a transformation point.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a dip switch.

Background Art

[0002] Dip switches are known. For example, Patent Document 1 discloses a piano-type dip switch including a lever as an operation unit capable of switching on / off, a movable leaf including a drive unit engaged with the lever, a fixed leaf that contacts the drive unit when the lever is turned on, and a case that houses each of the lever, the movable leaf, and the fixed leaf.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When mounting the dip switch described in Patent Document 1 on a printed circuit board, for example, if soldering of the movable leaf is performed while the drive unit is being pressed by the lever, irreversible deformation that is not elastic deformation remains in the drive unit due to the heat during soldering, and the spring property becomes so weak that the leaves do not contact each other even when the lever is turned on, and there is a risk of poor contact due to insufficient contact pressure with the fixed leaf.

[0005] As a countermeasure against this, although the position of the lever is visually confirmed before mounting, there is a problem such as overlooking the confirmation of the position of the lever or mounting it while the lever operation is incorrect as an example.

[0006] The present invention has been made in view of the above-mentioned points, and aims to provide a DIP switch that can prevent irreversible thermal deformation of the contact terminals when mounted on a printed circuit board, thereby maintaining the switch function of the contact terminals in good condition. [Means for solving the problem]

[0007] The DIP switch according to the present invention is characterized by comprising: a housing; an operating member held in the housing having a knob portion accessible from outside the housing and being able to transition between one position and another position by operation of the knob portion; a terminal 1 held in the housing; another terminal held in the housing and having a fixing portion fixed to the housing and a deformable portion that separates from the terminal 1 when the operating member is in the other position and contacts the terminal 1 when pressed and deformed when the operating member is in the position 1; and a temperature-sensing element including a deformable member made of a shape memory alloy that engages with the operating member in such a way that the position of the operating member changes in accordance with the deformation and is in contact with the fixing portion of the other terminal, and exhibits elasticity such that its shape returns to the shape in which the operating member is in the other position when it is at a temperature above its transformation point. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the DIP switch according to Example 1. [Figure 2] This is a cross-sectional view of the DIP switch according to Example 1. [Figure 3] This is a cross-sectional view of the DIP switch according to Example 1. [Figure 4] This is a perspective view of a modified DIP switch according to Example 1. [Figure 5] This is a cross-sectional view of a DIP switch according to a modified example of Example 1. [Figure 6] This is a cross-sectional view of a DIP switch according to a modified example of Example 1. [Figure 7] This is a cross-sectional view of a DIP switch according to a modified example of Example 1. [Figure 8]This is a cross-sectional view of a DIP switch according to a modified example of Example 1. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, identical components are denoted by the same reference numerals, and descriptions of redundant components are omitted. [Examples]

[0010] Figure 1 is a perspective view showing a DIP switch 10 according to Embodiment 1. The housing 11 has a roughly rectangular parallelepiped shape and has space inside. That is, the housing 11 is hollow inside. The housing 11 is made of a resin such as polypropylene. Hereinafter, the direction perpendicular to the upper surface 11T of the housing 11 will be described as the up and down direction.

[0011] Each housing 11 is formed extending from the end of the top surface 11T to one side surface 11S, and has multiple openings OP arranged spaced apart from each other along the long side of the top surface 11T. In other words, multiple openings OP are arranged spaced apart from each other at the corners of the housing 11 formed by the top surface 11T and one side surface 11S. In this embodiment, four openings OP are formed.

[0012] The operating parts 12, which serve as operating components, are held by the housing 11 such that a portion of each of the four openings OP is exposed. Each of the operating parts 12 has a rectangular parallelepiped-shaped knob portion 12P that protrudes outward from the side surface 11S and can be operated from outside the housing 11. The operating parts 12 are made of a resin such as polyamide.

[0013] Each of the operating parts 12 can be freely switched between an ON position and an OFF position for the DIP switch 10 by pressing down or pushing up the knob portion 12P. In other words, the DIP switch 10 is a piano-type DIP switch with 4 poles.

[0014] In this embodiment, the posture of the operation unit 12 when the knob portion 12P faces in a direction perpendicular to the side surface 11S of 1 is in the off state, and the posture of the operation unit 12 when the knob portion 12P is lowered obliquely downward with respect to the side surface 11S of 1 is in the on state.

[0015] The movable terminal 13 is a terminal made of an elongated metal plate body that extends downward through a base portion (not shown in FIG. 1) forming the bottom of the housing 11 from inside the housing 11. The movable terminals 13 are respectively arranged below each of the openings OP. That is, four movable terminals 13 are arranged at intervals along the longitudinal side of the upper surface 11T.

[0016] The fixed terminal 14 is a terminal made of an elongated metal plate body that extends downward through a base portion (not shown in FIG. 1) forming the bottom of the housing 11 from inside the housing 11. Similar to the movable terminal 13, four fixed terminals 14 (only one is shown in the figure) are arranged at intervals along the longitudinal side of the upper surface 11T. Each of the fixed terminals 14 is arranged to face each of the movable terminals 13 in the short side direction of the upper surface 11T.

[0017] A pair of movable terminals 13 and fixed terminals 14 facing each other form a switch structure in which the movable terminals 13 contact and separate from each other by deformation inside the housing 11.

[0018] FIG. II is a cross-sectional view taken along the line 2-2 of the dip switch 10 in FIG. I. In FIG. II, a cross-section of the dip switch 10 when the operation unit 12 is in the off posture is shown.

[0019] The housing 11 is composed of a flat base portion 16 having a rectangular upper surface shape and a box-shaped case 17 that covers the side surface and the upper surface of the base portion 16 and forms a space inside together with the upper surface of the base portion 16.

[0020] Case 17 has a stepped cross-section consisting of a first surface 11SA formed at a lower position than the opening OP and perpendicular to the side surface 11S, and a second surface 11SB extending upward from one end of the first surface 11SA and connected to the opening OP.

[0021] Furthermore, the case 17 has a protruding portion 11A that protrudes downward on the back surface of the upper surface 11T.

[0022] The operating section 12 has a shaft portion 12S that penetrates it along the longitudinal side of the upper surface 11T (along the depth direction in the figure). Both ends of the shaft portion 12S are housed in notches (not shown) formed in the wall portions 11W that are formed between the operating sections 12 inside the housing 11. In other words, the operating section 12 is rotatably supported by the case 17 via the shaft portion 12S.

[0023] The operating section 12 contacts the protruding section 11A when the device is in the off position as described above, preventing the knob portion 12P from moving further upward, that is, from rotating clockwise in the diagram.

[0024] As described above, the fixed terminal 14 has a through-port 14P that penetrates the base portion 16 vertically, with one end exposed to the outside and the other end reaching the inside of the housing 11, and a terminal contact portion 14C that extends from the other end of the through-port 14P, bent along the upper surface of the base portion 16. In other words, the fixed terminal 14 has an L-shape.

[0025] As described above, the movable terminal 13 has a through-port 13P that penetrates the base portion 16 in the vertical direction, with one end exposed to the outside and the other end reaching the inside of the housing 11, and a terminal contact portion 13C that extends from the other end of the through-port 13P, bending along the upper surface of the base portion 16.

[0026] Furthermore, the terminal contact portion 13C has a fixed portion P1 that is formed continuously from the other end of the through portion 13P and extends in contact with the upper surface of the base portion 16, and a deformed portion P2 that bends upward from one end of the fixed portion P1 and extends above a part of the terminal contact portion 14C of the fixed terminal 14 while being separated from the upper surface of the base portion 16.

[0027] The deformable portion P2 is formed to engage with the operating portion 12 at the engaging portion E1 when the operating portion 12 is in the off position. The deformable portion P2 is formed to be pushed down and deformed in accordance with the rotation of the operating portion 12.

[0028] The movable terminal 13 and the fixed terminal 14 are formed, for example, by bending a metal plate made of a Cu (copper) alloy as shown in Figure 2, and then applying Au (gold) plating to its surface.

[0029] The shape memory alloy spring 19, used as a temperature-sensing element, is a cylindrical compression coil spring. The shape memory alloy spring 19 is a so-called shape memory alloy that, when deformed by an external force at a temperature below its transformation point, retains its changed shape even after the external force is removed, and returns to its original shape when the temperature rises above its transformation point.

[0030] The shape memory alloy spring 19 is engaged by contacting the operating part 12 at one end of the engaging part E2, and by contacting the fixed part P1 of the terminal contact part 13C of the movable terminal 13 at the other end.

[0031] The shape memory alloy spring 19 is made of a shape memory alloy such as a Ti-Ni (titanium-nickel) alloy.

[0032] Figure 3, like Figure 2, is a cross-sectional view of the DIP switch 10 along line 2-2 in Figure 1. In Figure 3, the cross-section of the DIP switch 10 is shown when the operating unit 12 is in the ON position.

[0033] The deformed portion P2 of the terminal contact portion 13C of the movable terminal 13 is deformed into a substantially flat shape by the pressure from the operating portion 12 at the engaging portion E1 when the operating portion 12 is in the ON position, and comes into contact with the terminal contact portion 14C of the fixed terminal 14 which is arranged on the base portion 16.

[0034] When the operating part 12 is in the ON position, the shape memory alloy spring 19 is compressed by the pressure from the operating part 12 at the engaging part E2. At this time, the shape memory alloy spring 19 is held between the operating part 12 and the fixed part P1 of the terminal contact part 13C of the movable terminal 13 while maintaining its compressed shape as the first shape.

[0035] Here, using Figures 2 and 3, the function of the shape memory alloy spring 19 when mounting the DIP switch 10 on the printed circuit board in this embodiment will be explained. In the following explanation, we will describe the case in which the DIP switch 10 is soldered to the printed circuit board with the operating part 12 in the ON position, as shown in Figure 3.

[0036] In the implementation of the DIP switch 10, the portion of the through-hole 13P of the movable terminal 13 and the through-hole 14P of the fixed terminal 14 that is exposed to the outside from the base portion 16 is soldered to the printed circuit board.

[0037] At this time, when the heat from soldering is transferred to the shape memory alloy spring 19 via the movable terminal 13, the shape memory alloy spring 19 exerts an elastic force that returns it from its deformed shape to its original shape when its temperature exceeds the transformation point. In other words, the shape memory alloy spring 19 exerts an elastic force at the engaging portion E2 that returns it from the compressed shape shown in Figure 3 to the original shape shown in Figure 2.

[0038] As a result, the operating unit 12 rotates clockwise in the figure due to the elastic force of the shape memory alloy spring 19, transitioning from the ON position to the OFF position. In other words, the pressure of the operating unit 12 on the deformed portion P2 of the movable terminal 13 is eliminated, and the deformed portion P2 and the terminal contact portion 14C of the fixed terminal 14 are separated.

[0039] Therefore, for example, even if the DIP switch 10 is installed with the operating unit 12 in the ON position, the operating unit 12 automatically returns to the OFF position. This prevents the deformable part P2 from receiving heat during soldering while in the ON position pressed by the operating unit 12, and from remaining in the ON position even after the pressure is released.

[0040] Therefore, with the DIP switch 10 of this embodiment, even if the operating position of the operating part 12 is not visually checked during mounting to the printed circuit board and soldering is performed in the ON position, the operating part 12 is set to the OFF position during mounting to prevent deformation of the deformable part P2, thereby maintaining the switch function of the movable terminal 13 and the fixed terminal 14 in good condition.

[0041] In this embodiment, the case where the DIP switch 10 has four poles has been described, but the number of poles may be more or less than this. For example, the DIP switch 10 may have one pole.

[0042] In this embodiment, the shape memory alloy spring 19 is described as having a cylindrical shape, but it is not limited to this, and may have a conical or barrel shape, for example. Also, although the shape memory alloy spring 19 is described as a compression coil spring, it is not limited to this. For example, the shape memory alloy spring 19 may be a leaf spring bent into a V-shape.

[0043] In this embodiment, the housing 11 is provided with a movable terminal 13 and a fixed terminal 14 that penetrate vertically through the base portion 16 and extend downwards from the housing 11, but the shape of the terminals is not limited to this. For example, each terminal may have a so-called leaf shape and be exposed to the outside from one side 11S of the housing 11 and the side opposite to the first side 11S, and mounted on the surface of the printed circuit board.

[0044] In this embodiment, the opening OP is formed extending from the upper surface 11T to the side surface 11S, but the form of the opening is not limited to this. For example, the opening OP may be formed only on the side surface 11S, and the upper part of the operating section 12 may be covered by the upper surface 11T of the housing 11. In other words, the operating section 12 may be exposed only from the side surface 11S.

[0045] Furthermore, the housing 11 may be equipped with a mechanism to prevent the shape memory alloy spring 19, which is held in place by the operating section 12 and the fixing section P1 of the movable terminal 13, from tilting due to vibrations that occur during the transportation or installation of the DIP switch 10. For example, a member may be provided on the wall 11W of the housing 11 to support the shape memory alloy spring 19 from the side, to the extent that it does not affect the shape change of the shape memory alloy spring 19.

[0046] [Example 1] Below, a modification 1 of Example 1 will be described with reference to Figures 4 and 5. Figure 4 is a perspective view of the DIP switch 20 according to Modification 1. Figure 5 is a cross-sectional view of the DIP switch 20 in Figure 4 along line 5-5.

[0047] The DIP switch 20 differs from that of Embodiment 1 in that a new opening is formed in the housing 11, but other configurations, such as the arrangement of the operating part 12 and the shape memory alloy spring 19 within the housing 11, are the same as those of Embodiment 1.

[0048] In this modified example, as shown in Figure 4, the DIP switch 20 has square-shaped openings OPA formed below each of the openings OP on one side surface 11S of the housing 11. That is, four openings OPA are arranged spaced apart from each other along the long side of the top surface 11T, similar to the openings OP.

[0049] As shown in Figure 5, the lower end of the opening OPA coincides with the upper end of the base portion 16. The opening OPA is formed in a position that allows access from the outside to the shape memory alloy spring 19, which is in contact with the fixed portion P1 of the terminal contact portion 13C of the movable terminal 13, through the opening OPA.

[0050] In this modified example, the shape memory alloy spring 19 can be removed from the opening OPA after the DIP switch 20 has been mounted on the printed circuit board. In other words, the opening OPA is the exit point for the shape memory alloy spring 19.

[0051] According to this modified version of the DIP switch 20, since the housing 11 is provided with an opening OPA for removing the shape memory alloy spring 19, it is possible to prevent the operating unit 12 from malfunctioning after the DIP switch 20 is installed.

[0052] Specifically, for example, when the operating unit 12 is set to the ON position (the shape memory alloy spring 19 is in a compressed shape) after the DIP switch 20 has been installed and power is supplied to the movable terminal 13, the heat generated during the operation of the DIP switch 20 causes the shape memory alloy spring 19 to return to its original shape, preventing the operating unit 12 from unintentionally returning to the OFF position.

[0053] In other words, with this modified DIP switch 20, the shape memory alloy spring 19 can be removed after the DIP switch 20 is installed, so the shape memory alloy spring 19 can be used selectively to install the DIP switch 20.

[0054] The opening OPA shown in Figures 4 and 5 may be closed after the shape memory alloy spring 19 is removed. Figure 6 shows the removal opening cover 21 that closes the opening OPA in the cross-sectional view shown in Figure 5.

[0055] As shown in Figure 6, by covering the opening OPA from the outside of the housing 11 with the removal cover 21, it is possible to prevent dust and moisture from entering the housing 11 through the opening OPA after the shape memory alloy spring 19 has been removed.

[0056] The dispensing opening cover 21 is preferably made of a material that can seal the opening OPA, and may be made of the same material as the housing 11 or other materials such as rubber.

[0057] Furthermore, the opening OPA may be configured to always be sealed by the removal cover 21 except when removing the shape memory alloy spring 19. In other words, the removal cover 21 may be configured to be easily attached and detached.

[0058] [Differentiation 2] A modified example 2 of Embodiment 1 will be described below with reference to Figures 7 and 8. Figure 7 shows a cross-sectional view of the DIP switch 30 when the operating unit 12 is in the OFF position. Figure 8 shows a cross-sectional view of the DIP switch 30 when the operating unit 12 is in the ON position.

[0059] The DIP switch 30 differs from that of Embodiment 1 in that the ON and OFF positions of the operating unit 12 are different, but the rest of the configuration is the same as that of Embodiment 1.

[0060] As shown in Figures 7 and 8, the off and on positions of the operating section 12 of the DIP switch 30 are reversed compared to the DIP switch 10 of Embodiment 1. That is, in this modified example, the position of the operating section 12 when the knob portion 12P is facing perpendicular to the side surface 11S of 1 is the on state, and the position of the operating section 12 when the knob portion 12P is lowered diagonally downward relative to the side surface 11S of 1 is the off state.

[0061] In this modified example, the shape memory alloy spring 19 is engaged by contacting the operating portion 12 at one end of the engaging portion E2, and the other end is in contact with the terminal contact portion 14C of the fixed terminal 14.

[0062] Therefore, for example, even if the DIP switch 10 is implemented with the operating unit 12 in the ON position, the operating unit 12 will rotate counterclockwise in the figure due to the elastic force of the shape memory alloy spring 19, transitioning from the ON position to the OFF position.

[0063] Therefore, in this modified example of the DIP switch 30, when the deformable part P2 is pressed against the operating part 12 and in the ON state, it receives heat during soldering, and it is possible to prevent it from remaining in the ON state even after the pressure is released.

[0064] Therefore, with the DIP switch 10 of this embodiment, even if the operating position of the operating part 12 is not visually checked during mounting to the printed circuit board and soldering is performed in the ON position, the operating part 12 is set to the OFF position during mounting to prevent deformation of the deformable part P2, thereby maintaining the switch function of the movable terminal 13 and the fixed terminal 14 in good condition.

[0065] The manner in which the operating part 12 and the deformed part P2 of the movable terminal 13 engage is not limited to those shown in the above-described embodiments and modifications. For example, the shape and arrangement of the operating part 12, the movable terminal 13, and the fixed terminal 14 may be changed so that the switch is off when the knob portion 12P of the operating part 12 is pressed down and the movable terminal 13 is pressed, and the switch is on when the knob portion 12P is pushed up and the movable terminal 13 is not pressed. [Explanation of Symbols]

[0066] 10, 20, 30 DIP switches 11 cabinets 12 Control section 13 Fixed terminal 14 Movable terminal 16 Base section 17 cases 19 Shape memory alloy springs 21 Removal opening cover

Claims

1. The casing and An operating member is held in the housing and has a knob portion accessible from outside the housing, which can be freely switched between one position and another position by operating the knob portion. One terminal held in the housing, A fixing portion held in the housing and fixed to the housing, and another terminal having a deformable portion that separates from terminal 1 when the operating member is in another position and deforms when pressed and contacts terminal 1 when the operating member is in position 1, A temperature-sensing element includes a deformable member made of a shape memory alloy that engages with the operating member such that the orientation of the operating member changes in accordance with deformation, and is in contact with the fixing portion of the other terminal, and exhibits elasticity such that when the temperature is above the transformation point, the shape returns to the shape in which the operating member is in the other orientation; A DIP switch characterized by having the following features.

2. The DIP switch according to claim 1, characterized in that the deformable member takes on a first shape when the temperature is below the transformation point and the operating member is in the first position, and returns from the first shape to a shape that causes the operating member to take on the other position when the temperature rises above the transformation point.

3. The DIP switch according to claim 1 or 2, characterized in that the housing is provided with an outlet for removing the temperature sensing element.

4. The DIP switch according to claim 1 or 2, characterized in that the DIP switch is piano-shaped.

5. The DIP switch according to claim 1 or 2, characterized in that the deformation member is a compression coil spring.

6. The DIP switch according to claim 1 or 2, characterized in that the deformable member is a leaf spring having a V-shape.

7. The DIP switch according to claim 1 or 2, characterized in that the deformable member is made of a titanium-nickel alloy.

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