JP2011048908A - Rotary switch and measuring device - Google Patents

Abstract

A connection failure caused by sliding between a fixed contact or a substrate surface and a moving contact is prevented.
A rotating member 41, a moving contact 42 attached to the rotating member 41, a plurality of fixed contacts 31 formed on a substrate 12, and a direction away from a rotating center 41a of the rotating member 41. The concave contact 23a and the projection 23b protruding toward the rotation center 41a are provided with the front panel 21 alternately formed on the edge 23 of the opening 22, and the fixed contact 31 includes the rotation center 41a and the recess The rotating member 41 includes a dial part 51, a rod part 52 protruding from the central part 51a of the dial part 51, and an open end 53b when the rotating member 41 rotates. And an arm portion 53 that elastically deforms so as to come into contact with and separate from the substrate 12 in accordance with the contact and separation operation with respect to the rotation center 41 a when moving along the edge portion 23. Attached to the middle part To contact and separation with respect to the fixed contact 31 along with the elastic deformation of the over arm portion 53.
[Selection] Figure 3

Description

  The present invention relates to a rotary switch for connecting a moving contact and a fixed contact by rotating a rotating member, and a measuring device including the rotary switch.

  As this type of rotary switch, a rotary switch device disclosed in Japanese Patent Laid-Open No. 10-241495 is known. This rotary switch device is a switch incorporated in a tester and used to switch the measurement mode of the tester, and includes a dial, a click mechanism for rotating (rotating) the dial, and a contact brush (moving contact). ) And a switch body composed of a conductive contact (fixed contact). In this rotary switch device, when the dial is turned, the moving contact moves along with the turning and is brought into sliding contact with the fixed contact, so that both are electrically connected. Thereby, the measurement mode of the tester is switched.

JP-A-10-241495 (page 2-3, FIG. 1-3)

  However, this type of conventional rotary switch including the above rotary switch device has the following problems. That is, in this type of conventional rotary switch, the fixed contact is provided on the substrate in the tester, and the movable contact is moved in contact with the surface of the substrate. In this case, in order to electrically connect the moving contact and the fixed contact reliably, it is necessary to press the moving contact against the surface of the substrate. For this reason, in this type of conventional rotary switch, plating for reducing contact resistance (for example, gold plating) formed on the surface of a moving contact or a fixed contact is caused by movement (sliding) of the moving contact in a pressed state. It may be scraped off. In this case, when the plating is scraped off, the surfaces of the moving contact and the fixed contact are oxidized and covered with a metal oxide as an insulator, which may cause a connection failure between the two contacts. In addition, the metal oxide on each contact surface and the resist layer formed on the surface of the substrate are scraped off by sliding of the moving contact, and the scraped metal oxide and resist layer powder are transferred to the moving contact and the fixed contact. There is also a risk that a connection failure between the two will occur.

  The present invention has been made in view of such problems, and it is a main object of the present invention to provide a rotary switch and a measurement device that can prevent a connection failure caused by sliding between a fixed contact or a substrate surface and a moving contact. To do.

  In order to achieve the above object, the rotary switch according to claim 1 is provided with a rotating member rotatably disposed on the case body, and is attached to the rotating member and moves as the rotating member rotates. And a moving contact that is formed so as to be separated from each other on a circle centered on the rotation center of the rotation member on the substrate disposed in the case body and connected to the movement contact that has moved to the formation position. A rotary switch having a plurality of fixed contacts, wherein the rotary switch has an opening and is opposed to the substrate in the case body and is recessed in a direction away from the rotation center and the rotation center And projecting portions protruding toward the edge of the opening portion, and the fixed contact is the center of rotation in plan view in a state where the substrate is disposed in the case body. And said The rotating member includes a dial part for rotating operation that rotates the rotating member, and a protruding part that protrudes from the center of the dial part toward the substrate side. A rod portion provided on the dial portion and a base end portion are fixed to the rod portion and configured to be able to press the edge portion of the opening portion by an open end portion. An arm portion that is elastically deformed so as to come in contact with and separate from the substrate in accordance with the contact and separation operation with respect to the rotation center when the open end portion moves along the edge portion, The arm portion is attached to an intermediate portion between the base end portion and the open end portion, and is brought into contact with and separated from the fixed contact with the elastic deformation of the arm portion when the rotating member is rotated.

  The rotary switch according to a second aspect is the rotary switch according to the first aspect, wherein the arm portion is curved so as to protrude from the dial portion toward the substrate.

  According to a third aspect of the present invention, there is provided a measuring apparatus comprising: the rotary switch according to the first or second aspect; and a measuring circuit whose operation is switched according to a rotating operation of the rotary switch with respect to the rotating member.

  In the rotary switch according to claim 1 and the measuring device according to claim 3, the open end of the arm portion moves along the edge of the opening in which the concave portion and the convex portion are alternately formed. The arm portion is elastically deformed as the open end portion moves toward and away from the rotation center of the rotation member, and the arm portion contacts and separates from the substrate by this elastic deformation. For this reason, according to the rotary switch and the measuring device, the moving contact is set while the open end of the arm moves along the convex portion of the edge, that is, while the moving contact moves in the non-forming section of the fixed contact. The moving contact can be reliably connected to the fixed contact when the open end is positioned in the recessed portion of the edge portion away from the substrate. For this reason, according to the rotary switch and the measuring apparatus, it is ensured that the resist layer formed on the surface of the substrate and the plating formed on the surfaces of the fixed contact and the moving contact are scraped off by the sliding of the moving contact. As a result, it is possible to reliably prevent connection failure caused by sliding between the fixed contact or the substrate and the moving contact.

  Further, according to the rotary switch according to claim 2 and the measuring device according to claim 3, since the arm portion is curved so as to protrude from the dial portion toward the substrate, the open end portion of the arm portion is When moving along the convex part and approaching the rotational center of the rotational member, the arm part is securely and easily elastically deformed so that the intermediate part is close to the substrate, and the open end is positioned in the concave part. The arm portion can be elastically deformed (returned) reliably and easily so that the intermediate portion is separated from the substrate when the center is separated from the rotation center. For this reason, according to the rotary switch and the measuring device, the moving contact attached to the intermediate portion of the arm portion is more reliably separated from the substrate in the non-forming section of the fixed contact, and the fixed contact is formed at the position where the fixed contact is formed. Can be connected more reliably.

1 is a perspective view of a measuring device 1. FIG. 1 is an exploded perspective view of a measuring device 1. FIG. 3 is a plan view showing a configuration of a rotary switch 13. FIG. It is the XX sectional view taken on the line in FIG. FIG. 6 is a first explanatory diagram illustrating the operation of the rotary switch 13. It is the YY sectional view taken on the line in FIG. FIG. 6 is a second explanatory diagram explaining the operation of the rotary switch 13. FIG. 9 is a sectional view taken along line ZZ in FIG. 7. 3 is a perspective view of a moving contact 42. FIG. 3 is a perspective view of a moving contact 142. FIG.

  Hereinafter, embodiments of a rotary switch and a measuring device will be described with reference to the accompanying drawings.

  First, the configuration of the measuring apparatus 1 will be described with reference to the drawings. A measuring apparatus 1 shown in FIG. 1 is, as an example, a portable measuring apparatus that measures electrical physical quantities such as voltage, current, and resistance, and includes a main body 2 and a measurement probe 3 as shown in FIG. , 3.

  As shown in FIG. 2, the main body 2 includes a case body 11, a substrate 12, and a rotary switch 13. As shown in the figure, the case body 11 is formed in a shallow dish shape and includes an upper case 11a and a lower case 11b that can be fitted to each other. In the fitted state of both cases 11a and 11b, A space in which 12 is accommodated is formed. In this case, the front panel 21 of the upper case 11a is formed with a display window 24 through which a liquid crystal display panel (not shown) disposed in the case body 11 can be seen.

  Further, the front panel 21 functions as a plate member that constitutes a part of the rotary switch 13. Specifically, as shown in FIG. 3, the front panel 21 has an opening 22 in which the open end 53 b of the arm 53 of the rotating member 41 of the rotary switch 13 contacts the edge 23. Yes. Further, at the edge portion 23 of the opening 22, a concave portion 23 a that is recessed in a direction away from the rotation center 41 a and an arc-shaped convex portion 23 b that protrudes toward the rotation center 41 a of the rotation member 41 are alternately arranged. Is formed. That is, the edge part 23 of the opening part 22 is formed in the waveform which the recessed part 23a and the convex part 23b connect alternately. In this case, the opening 22 is formed to have a larger diameter than a circle C connecting the formation positions of the fixed contacts 31 described later formed on the substrate 12. In FIG. 5 and FIG. 7 described later, the rotary switch 13 in a state where the dial 51 (see FIG. 2) is seen through is shown.

  As shown in FIG. 2, the substrate 12 is disposed inside the case body 11 so as to face the front panel 21 of the upper case 11a. Further, as shown in FIG. 3, a plurality of fixed contacts 31 constituting a part of the rotary switch 13 are formed on the substrate 12. In this case, each fixed contact 31 is centered on the rotation center 41a of the rotation member 41 of the rotary switch 13 in a plan view with the substrate 12 disposed in the case body 11, as shown in FIG. Formed on a line C1 that connects the recess 23a of the opening 22 of the front panel 21 and the rotation center 41a (that is, on the intersection of the circle C and the line L1). They are separated from each other. Further, each fixed contact 31 is connected to the moving contact 42 when the moving contact 42 moves to the formation position in accordance with the rotation of the rotating member 41. In the substrate 12, the fixed contact 31 is not formed on the line L2 that connects the convex portion 23b of the opening 22 of the front panel 21 and the rotation center 41a.

  As shown in FIG. 2, a measurement circuit 32 that measures an electrical physical quantity based on an electrical signal input through the probes 3 and 3 is disposed on the substrate 12. In this case, the operation (measurement mode) of the measurement circuit 32 is switched according to a turning operation for turning a turning member 41 of the rotary switch 13 described later. A conductive pattern other than the fixed contact 31 is formed on the substrate 12 and a power supply unit, a liquid crystal display panel, and the like are mounted. However, these are not shown in FIGS.

  As shown in FIGS. 3 and 4, the rotary switch 13 includes a rotating member 41, a moving contact 42, a part of the front panel 21 (part where the opening 22 is formed), and the fixed contact 31 described above. It is prepared for. The rotating member 41 includes a dial part 51, a rod part 52, and two arm parts 53, and is disposed on the case body 11 so as to be rotatable.

  As shown in FIGS. 2 and 4, the dial part 51 is formed in a disk shape and is disposed on the front panel 21 side of the case body 11, and is used for a turning operation for turning the turning member 41. It is done. As shown in FIG. 4, the rod portion 52 protrudes from the center portion 51 a of the dial portion 51 (the rotation center 41 a of the rotation member 41) toward the substrate 12 side (lower side in the figure). 51. In this case, the tip 52a of the rod 52 is inserted through an insertion hole formed in the substrate 12 and is rotatably supported by the lower case 11b, as shown in FIG.

  As shown in FIGS. 3 and 4, the arm portion 53 is formed in a belt shape and is configured to be elastically deformable. In this case, the arm portion 53 has a base end portion 53a (the lower end portion in FIG. 4 on the side of the substrate 12) fixed to the tip end portion 52a side of the rod portion 52, and the front panel 21 by the open end portion 53b. The edge portion 23 of the opening 22 is pressed by the elastic force. For this reason, the open end 53b of the arm 53 and the edge 23 of the opening 22 are always kept in contact with each other. Moreover, as shown in FIG. 4, the arm part 53 is formed in the arch shape which protrudes in the direction which goes to the board | substrate 12 from the dial part 51, and curves like a bow.

  In the rotary switch 13, the edge 23 of the opening 22 and the open end 53b of the arm 53 are always in contact with each other. Therefore, when the rotating member 41 is rotated, the open end 53b is opened. It moves along the edge 23 of 22. In this case, since the edge 23 of the opening 22 is formed in a corrugated shape, the open end 53 b moves to the rotation center 41 a of the rotation member 41 when the open end 53 b moves along the edge 23. The arm portion 53 is elastically deformed so that the intermediate portion is brought into contact with and separated from the substrate 12. More specifically, when the open end 53 b is in contact with the recess 23 a of the edge 23, the arm portion 53 is close to the substrate 12 and the open end 53 b is connected to the protrusion 23 b of the edge 23. When in contact, the intermediate portion is elastically deformed so as to be separated from the substrate 12. The rotating member 41 is produced by integrally molding the dial portion 51, the rod portion 52, and the arm portions 53, 53 with resin as an example.

  As shown in FIG. 9, the moving contact 42 includes a flat base portion 42a and leg portions 42b formed so as to protrude from the base portion 42a. In this case, the moving contact 42 is produced by, for example, bending a material having conductivity and elasticity (for example, a material obtained by performing gold plating on the surface of a phosphor bronze plate). Further, as shown in FIG. 4, the moving contact 42 has the base portion 42a fixed to the intermediate portion of the base end portion 53a and the open end portion 53b of the arm portion 53, so that the distal end portion of the leg portion 42b rotates. The member 41 is attached to the arm portion 53 so as to protrude away from the rotation center 41a of the member 41. The moving contact 42 moves with the turning operation of the turning member 41. Further, the moving contact 42 operates so as to come in contact with and separate from the fixed contact 31 (the surface of the substrate 12) in accordance with the elastic deformation of the arm portion 53 described above when the rotating member 41 is rotated (FIG. 4). , 6). More specifically, the moving contact 42 comes into contact with the fixed contact 31 (the surface of the substrate 12) when the open end 53b of the arm 53 is in contact with the recess 23a of the edge 23 in the opening 22. When the end portion 53 b is in contact with the convex portion 23 b of the edge portion 23, the end portion 53 b is separated from the surface of the substrate 12.

  Next, the usage method of the measuring apparatus 1 is demonstrated with reference to drawings.

  In this measuring apparatus 1, as shown in FIG. 3, the marker M attached to the dial 51 of the rotary switch 13 and the power off mark attached to the front panel 21 ("OFF" shown in the figure). Mark) (when the measuring device 1 is in a power-off state), the power supply to the measurement circuit 32 is stopped. In this state, as shown in the figure, the open end portion 53 b of the arm portion 53 is located in the recess portion 23 a constituting the edge portion 23 of the opening portion 22 in the front panel 21, and the open end portion is caused by the elastic force of the arm portion 53. 53 b presses the edge 23. In this case, when the open end portion 53b of the arm portion 53 is positioned in the recess 23a, the open end portion 53b is largely separated from the rotation center 41a of the rotation member 41 as shown in FIG. 53 is curved with a large curvature. For this reason, in this state, as a result of the intermediate portion of the arm portion 53 approaching the substrate 12, the moving contact 42 attached to the intermediate portion of the arm portion 53 contacts the surface of the substrate 12.

  Next, for example, when measuring the DC voltage supplied to the measurement object, the dial 51 is rotated in the direction of arrow A shown in FIG. At this time, the open end 53 b moves along the edge 23 of the opening 22. In this case, as shown in FIG. 5, when the open end portion 53 b moves from the concave portion 23 a of the edge portion 23 toward the convex portion 23 b, the open end portion 53 b gradually approaches the rotation center 41 a of the rotation member 41. Then, as shown in FIG. 6, the arm portion 53 is elastically deformed so as to bend with a small curvature. For this reason, as shown in the figure, as a result of the intermediate portion of the arm portion 53 moving away from the substrate 12, the moving contact 42 attached to the intermediate portion of the arm portion 53 separates from the surface of the substrate 12. .

  Subsequently, the dial unit 51 is further rotated. In this case, when the open end portion 53 b moves from the convex portion 23 b of the edge portion 23 toward the next concave portion 23 a, the open end portion 53 b is gradually separated from the rotation center 41 a of the rotation member 41. Along with this, the arm portion 53 is elastically deformed so as to bend gradually with a large curvature, so that the intermediate portion of the arm portion 53 gradually approaches the substrate 12 due to this elastic deformation. As a result, the moving contact 42 attached to the intermediate portion of the arm portion 53 is moved toward the surface of the substrate 12.

  Next, as shown in FIG. 7, the dial M is dialed until the marker M attached to the dial 51 and the mark indicating the DC voltage attached to the front panel 21 ("DCV" mark shown in the figure) are opposed to each other. When the portion 51 is rotated, the open end portion 53 b of the arm portion 53 is positioned in the concave portion 23 a that constitutes the edge portion 23 of the opening portion 22 as shown in FIG. At this time, as shown in FIG. 8, the open end portion 53 b is largely separated from the rotation center 41 a of the rotation member 41, and the arm portion 53 is elastically deformed so as to be bent with a large curvature. Therefore, as a result of the intermediate portion of the arm portion 53 approaching the substrate 12, a pair of moving contacts 42 attached to the intermediate portion of the arm portion 53 are formed on the surface of the substrate 12, as shown in FIG. Pressed against the fixed contacts 31, 31. As a result, the fixed contacts 31 and the moving contact 42 are securely connected, and power is supplied to the measurement circuit 32 via the fixed contacts 31, 31 and the moving contact 42.

  Here, in the rotary switch 13, as described above, the rotation of the rotation member 41 when the open end 53 b of the arm 53 moves along the edge 23 during the rotation operation on the rotation member 41. The arm portion 53 is elastically deformed while changing the curvature in accordance with the contact / separation operation with respect to the center 41a, whereby the intermediate portion of the arm portion 53 is brought into contact with and separated from the surface of the substrate 12. In this case, while the open end portion 53b of the arm portion 53 moves along the convex portion 23b of the edge portion 23, that is, while the moving contact 42 moves in a section where the fixed contact 31 is not formed (non-forming section). The moving contact 42 is securely connected to the fixed contact 31 when the moving contact 42 is separated from the surface of the substrate 12 and the open end 53 b is positioned in the recess 23 a of the edge 23. Therefore, in this rotary switch 13, it is ensured that the resist layer formed on the surface of the substrate 12 and the plating formed on the surfaces of the fixed contact 31 and the moving contact 42 are scraped off by the sliding of the moving contact 42. It is possible to prevent it.

  Subsequently, the probes 3 and 3 are brought into contact (probing) with the measurement object. At this time, the measurement circuit 32 measures the DC voltage based on the electric signal input via the probes 3 and 3, and the liquid crystal display panel section displays the measured value. Next, when measuring an electrical physical quantity other than the DC voltage (AC voltage, current, resistance), the dial unit 51 is rotated. At this time, each component of the rotary switch 13 operates as described above, and the measurement mode of the measurement circuit 32 is switched. As a result, it becomes possible to measure other electrical physical quantities.

  As described above, in the rotary switch 13 and the measuring apparatus 1, the open end portion 53 b moves along the edge portion 23 of the opening portion 22 formed in a waveform when the rotating member 41 is rotated. The arm portion 53 is elastically deformed as the open end portion 53b contacts and separates from the rotation center 41a of the rotation member 41, and the arm portion 53 contacts and separates from the surface of the substrate 12 by this elastic deformation. For this reason, according to the rotary switch 13 and the measuring apparatus 1, the moving contact 42 moves through the non-formation section of the fixed contact 31 while the open end 53 b of the arm 53 moves along the convex portion 23 b of the edge 23. During the movement, the moving contact 42 is separated from the surface of the substrate 12, and the moving contact 42 can be reliably connected to the fixed contact 31 when the open end 53 b is positioned in the recess 23 a of the edge 23. Therefore, according to the rotary switch 13 and the measuring apparatus 1, the resist layer formed on the surface of the substrate 12 and the plating formed on the surfaces of the fixed contact 31 and the moving contact 42 slide the moving contact 42. As a result, it is possible to surely prevent the scraping off due to the sliding contact between the surface of the fixed contact 31 or the substrate 12 and the moving contact 42.

  Further, according to the rotary switch 13 and the measuring apparatus 1, the arm portion 53 is curved so as to protrude from the dial portion 51 toward the substrate 12, so that the open end portion 53b of the arm portion 53 is the convex portion 23b. The arm portion 53 is elastically deformed surely and easily so that the intermediate portion is close to the substrate 12, and the open end portion 53b is the recess portion 23a. Therefore, the arm portion 53 can be elastically deformed (returned) reliably and easily so that the intermediate portion is separated from the substrate 12 when being separated from the rotation center 41a. For this reason, according to the rotary switch 13 and the measuring device 1, the moving contact 42 attached to the intermediate portion of the arm portion 53 is more reliably separated from the substrate 12 in the non-forming section of the fixed contact 31 and the fixed contact. The fixed contact 31 can be more reliably connected at the position where the 31 is formed.

  In addition, although it described above about the example which curvedly formed the arm part 53, the arm part 53 formed so that it might become a straight state, for example when the open end part 53b is located in the recessed part 23a is also employable. Moreover, although the example provided with the two arm parts 53 was mentioned above, the structure provided with the one or three or more arm parts 53 is also employable. In addition, the configuration example in which the front panel 21 functions as a plate member constituting a part of the rotary switch 13 has been described above. However, the front panel 21 has an opening similar to the above-described opening 22 and is separate from the front panel 21. A configuration in which the formed plate member is disposed in the case body 11 (upper case 11a) may be employed.

  Further, the moving contact is not limited to the moving contact 42 described above. For example, as shown in FIG. 10, a moving contact provided with a flat base portion 142a and two leg portions 142b formed so as to protrude from the base portion 142a and connected to the fixed contacts 31, 31 respectively. 142 may be employed. In the above example, one moving contact 42 is connected to the pair of fixed contacts 31, 31, and power is supplied to the measurement circuit 32 via the contacts 42, 31, 31. A pair of moving contacts 42 respectively attached to the arm portion 53 are electrically connected using a conductive wire or the like, and one moving contact 42 is connected to only one fixed contact 31. A configuration is adopted in which power is supplied to the measurement circuit 32 via each moving contact 42, 42 and each fixed contact 31 (two fixed contacts 31 in total) when each moving contact 42 is connected to one fixed contact 31. You can also Further, the example in which the rotary switch 13 is provided in the portable measuring device 1 that measures electrical physical quantities such as voltage, current, and resistance has been described above. However, the measuring device such as a desktop measuring device or a waveform recording device is first used. It can be provided in other various electronic devices.

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 11 Case body 12 Board | substrate 13 Rotary switch 21 Front panel 22 Opening part 23 Edge part 23a Concave part 23b Convex part 31 Fixed contact 32 Measurement circuit 41 Rotating member 41a Rotation center 42,142 Moving contact 51 Dial part 51a Center part 52 Rod part 52a Tip part 53 Arm part 53a Base end part 53b Open end part C Circle L1 line

Claims (3)

A rotating member rotatably disposed in the case body, a moving contact attached to the rotating member and moving in accordance with the rotation of the rotating member, and the substrate in the case body A rotary switch comprising a plurality of fixed contacts connected to the moving contact that is formed so as to be separated from each other on a circle centered on the rotation center of the rotation member and moved to the formation position,
A concave portion that has an opening and is opposed to the substrate in the case body and that is recessed in a direction away from the rotation center and a convex portion that protrudes toward the rotation center are edges of the opening. Comprising plate members formed alternately,
The fixed contact is formed on a line connecting the rotation center and the recess in a plan view in a state where the substrate is disposed in the case body,
The rotating member includes a dial part for rotating operation for rotating the rotating member, and a rod part provided on the dial part so as to protrude from the center part of the dial part toward the substrate side. The base end portion is fixed to the rod portion and is configured to be able to press the edge portion of the opening portion by the open end portion, and the open end portion is along the edge portion when the rotation member is rotated. An arm part that is elastically deformed so as to come in contact with and separate from the substrate along with the contact and separation operation with respect to the rotation center when moving
The moving contact is attached to an intermediate portion between the base end portion and the open end portion of the arm portion, and with respect to the fixed contact with the elastic deformation of the arm portion when the rotating member rotates. Rotary switch that comes in and out.   The rotary switch according to claim 1, wherein the arm portion is curved so as to protrude from the dial portion toward the substrate.   3. A measuring apparatus comprising: the rotary switch according to claim 1; and a measuring circuit whose operation is switched according to a turning operation of the rotary switch with respect to the turning member.

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