JP6181837B2 - Portable radio clock - Google Patents

Description

  The present invention relates to a portable radio timepiece.

  In radio wave watches or radio pocket watches (hereinafter referred to as portable radio clocks) that receive standard radio waves using a long wave band or satellite radio waves (such as GPS) that use a very high frequency band and correct the time. When using a case made of metal for both the case and back cover, insulate the case and back cover that make up the case in order to avoid a decrease in reception sensitivity due to eddy currents generated inside the case near the antenna. It has been known. However, if the body and the back cover are completely insulated, when a momentary high potential difference is generated between them due to static electricity or the like, the generated current may flow into the movement, leading to malfunctions and the like.

  The following are known as countermeasures against static electricity in wristwatches. In Patent Document 1, a metal annular middle frame that accommodates a movement is provided in order to flow the charged charge flowing from the operation button to the electrode of the button-type battery through the case, and the annular middle frame is an inner periphery of the case peripheral side wall. A radio-controlled watch that is in contact with the surface and the battery holder is described. In Patent Document 2, as a static electricity countermeasure structure of a wristwatch, a coil spring is arranged between a metal upper and lower torches to make both conductive, and static electricity generated in the windshield is released to the human body through the lower torso. What to do is described. Further, Patent Document 3 describes that, for example, a silver paste is disposed at a part of a joint portion between a body member and a back cover member of a radio-controlled wristwatch to provide electrical continuity between them and take measures against static electricity.

JP 2006-215043 A Japanese Patent Application Laid-Open No. 11-109055 Japanese Patent No. 4695088

  The present invention has been made in view of such circumstances, and the problem to be solved is a portable radio timepiece in which the case and the back cover are both made of metal, while avoiding a decrease in reception sensitivity, such as malfunction due to static electricity. To reduce the occurrence.

  The invention disclosed in the present application in order to solve the above problems has various aspects, and the outline of typical aspects of the aspects is as follows.

  (1) A case in which a metal cylinder and a metal back cover are fixed so as to be insulated from each other, a movement accommodated in the case, and a conductive connection that electrically connects the cylinder and the back cover. A portable radio timepiece, wherein the movement has a ground terminal that is short-circuited to the back cover, and the connection member is provided on the opposite side of the ground terminal with respect to the center position of the movement.

  (2) (1) The portable radio timepiece in which the ground terminal is disposed near the periphery of the movement.

  (3) In (1) or (2), the connection member is a separate member from the movement, and the connection member is inserted between the case and the movement.

  According to the above aspect (1) of the present invention, in the portable radio timepiece in which the case and the back cover are both made of metal, the case and the back cover are grounded at a distance from each other, so that a stable ground potential can be obtained. Accordingly, it is possible to reduce the occurrence of malfunctions due to static electricity while avoiding a decrease in reception sensitivity.

  Further, according to the above aspect (2) of the present invention, the distance between the ground terminal and the connection member can be easily increased.

  In addition, according to the above aspect (3) of the present invention, the connection member can be inserted after the movement is inserted into the case, and the assembling work of the portable radio timepiece is easy.

It is the perspective view which looked at the portable radio timepiece concerning the embodiment of the present invention from the back. It is a disassembled perspective view which shows the internal structure of a portable radio timepiece. It is an external appearance perspective view which shows the shape of a connection piece. It is sectional drawing of the connection piece in the IVA-IVA line | wire of FIG. It is a connection piece seen from the arrow direction shown to IVB of FIG. It is the fragmentary sectional view of the thickness direction of the portable radio timepiece in the position including the connection piece before the back cover is attached. FIG. 6 is a partial cross-sectional view in the thickness direction of the portable radio timepiece at a position including a connection piece after the back cover is attached. It is a figure which shows the modification of previous embodiment. It is a perspective view which shows the external appearance of the connection piece in a modification.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view of a portable radio timepiece 1 according to an embodiment of the present invention as viewed from the back. In the present embodiment, the portable radio timepiece 1 is a wristwatch and has a function of receiving a so-called standard radio wave using a long wave band and automatically correcting the time. Of course, the portable radio timepiece 1 may receive satellite radio waves transmitted from GPS satellites that use the ultra high frequency band and correct the time based on time information included in the navigation data.

  A case 2 of the portable radio timepiece 1 includes a metal case 3 and a metal back cover 4, and the case 3 is provided with a band fixing portion 3 a for fixing the band. A crown 5 and a push button 6 are attached to the 3 o'clock side surface of the trunk 3.

  FIG. 2 is an exploded perspective view showing the internal structure of the portable radio timepiece 1. In the figure, the display of dials and pointers that are not directly related to the present invention is omitted. The portable radio timepiece 1 has a structure in which a movement 7 is accommodated inside a case 3 and is sealed with a back cover 4. A windshield 8 made of a transparent material such as glass or sapphire is mounted on the front side of the body 3. In this specification, the side on which the windshield 8 faces (the side on which the user visually recognizes the time) is called the front side, and the side on which the back cover 4 faces is called the back side.

  The movement 7 has a generally circular outer shape in plan view, and has a structure in which an electronic frame, various motors, gears, an antenna, a battery, and other parts are integrally assembled in an insulating frame called a base plate 70. It has become. In FIG. 2, a battery 71 attached to the back surface of the base plate 70 and a battery presser 72 that holds and holds the battery 71 from the back side are visible.

  Here, the material of the ground plane 70 is an appropriate synthetic resin, and in the case of this embodiment, the ground plane 70 is manufactured by injection molding of a thermoplastic resin. The battery 71 is preferably a secondary battery, and in the present embodiment, is a button-type lithium ion battery. The battery 71 is charged by a solar battery (not shown) or other appropriate power generation mechanism. In the present embodiment, the battery retainer 72 is a metal plate that retains the battery 71 from the back side, and is fixed to the base plate 70 by screws 73. In addition, a part of the battery retainer 72 is provided with a ground terminal 72 a that protrudes toward the back side. When the movement 7 is sealed by the back cover 4, the ground terminal 72 a is backed by the elastic force of the battery retainer 72. 4 is pressed against and electrically connected to the inner surface (the surface facing the front side). As a result, the potential of the surface facing the back side of the battery 71 (in this embodiment, the positive electrode) and the potential of the back cover 4 are equalized, and this potential is handled as the ground potential. The position of the ground terminal 72a is close to the periphery of the movement 7, as shown.

  By the way, as described above, when both the metal barrel 3 and the back cover 4 are fixed in a conductive state over the entire contact portion, an eddy current is generated in the vicinity of the antenna included in the movement 7, etc. There is a decrease in antenna reception sensitivity. Therefore, also in the present embodiment, the back cover 4 is fitted and fixed to the body 3 with an appropriate packing or caulking agent sandwiched therebetween, and the body 3 and the back cover 4 are generally insulated. ing. At this time, as described above, the back cover 4 is kept at the same ground potential as that of the positive electrode of the battery 71 by contacting the ground terminal 72a. It is not the same as the potential. In that case, if the potential of the body 3 temporarily becomes significantly different from the potential of the back cover 4 due to static electricity or the like, the current generated by the potential difference passes through the movement 7 to the back cover 4 and becomes noise. The movement 7 may malfunction, or the IC included in the movement 7 may be damaged.

  In order to avoid such a situation, in this embodiment, the connection piece 9 is provided at one place on the outer periphery of the main plate 70 of the movement 7.

  FIG. 3 is an external perspective view showing the shape of the connection piece 9. The connection piece 9 is made of a conductive material, which is an appropriate metal in the present embodiment, and has an insertion portion 90 extending in a tongue shape so as to be inserted between the outer periphery of the movement 7 and the inner periphery of the body 3, and the insertion portion 90. And a head portion 91 that is bent at an obtuse angle and is continuous and extends in a direction orthogonal to the extending direction of the insertion portion 90. Both ends of the head 91 are wings 92 bent so as to be slightly warped.

  4A is a cross-sectional view of the connection piece 9 taken along the line IVA-IVA of FIG. The IVA-IVA line in FIG. 3 is a plane passing through the center line of the connection piece 9. As shown in the figure, with respect to the insertion portion 90, the head 91 is provided such that the angle θ formed by both of them is an obtuse angle. The magnitude of θ is 120 ° in the present embodiment, but it is preferable that the angle be easy to handle during assembly, which will be described later, and it is generally desirable that the angle be about 105 ° to 135 °. FIG. 4B is the connection piece 9 seen from the arrow shown by IVB in FIG. The figure shows a structure in which both ends of the head 91 are bent to form a wing portion 92.

  In the present embodiment, the connecting piece 92 is manufactured by punching a metal plate into a generally T shape and then bending it. Manufacturing by bending is simple and low in cost.

  As shown in FIG. 2, the connection piece 9 is arranged such that the insertion portion 90 is inserted between the outer periphery of the movement 7 and the inner periphery of the trunk 3 from the back side. A part of the outer periphery of the base plate 70 of the movement 7 is provided with an insertion groove 70 a into which the insertion portion 90 is inserted and an insertion position display 70 c including a counterbore 70 b for housing the head 91. The insertion position display 70c is primarily for clearly indicating the position of the connection piece 9 when the portable radio timepiece 1 is assembled. Therefore, the insertion position display 70c does not have the insertion groove 70a and the counterbore 70b as shown here, but may be any mark indicating a certain position on the outer periphery of the movement 7. Good. However, when the insertion groove 70a and the counterbore 70b are provided as in the present embodiment, the insertion portion 90 is inserted into the insertion groove 70a when the connection piece 9 is inserted between the outer periphery of the movement 7 and the inner periphery of the body 3. Further, since the head 91 is housed in the counterbore 70b and positioned, it is possible to prevent the position of the connecting piece 9 from moving in the process of assembling the portable radio timepiece 1 to a position different from the planned position. Is done. The insertion groove 70a is a step where a part of the outer periphery of the base plate 70 is concave toward the center of the base plate 70, and the counterbore 70b is a part of the outer periphery of the surface facing the back side of the base plate 70. It is a step. As shown here, the insertion position display 70c may include both the insertion groove 70a and the counterbore 70b, may include only one of them, or may be a display with another mark. .

  Further, the position of the connection piece 9 that is clearly indicated by the insertion position display 70 c is opposite to the ground terminal 72 a with respect to the center position O of the movement 7.

  FIG. 5 is a partial cross-sectional view in the thickness direction of the portable radio timepiece 1 at a position including the connection piece 9 before the back cover 4 is attached. The position of the cross section shown in the figure is the position indicated by the line VV in FIG.

  As shown in the figure, before the back cover 4 is attached, the connecting piece 9 has the insertion portion 90 inserted between the outer periphery of the movement 7 and the inner periphery of the trunk 3, and the head portion 91 of the counterbore 70b. It gets caught on the back side. FIG. 6 shows the state in which the back cover 4 is attached to the body 3 in this state.

  FIG. 6 is a partial cross-sectional view in the thickness direction of the portable radio timepiece 1 at a position including the connection piece 9 after the back cover 4 is attached. As shown in the figure, the head portion 91 of the connection piece 9 comes into contact with the convex portion 40 of the back cover 4 and is pressed against and sandwiched by the movement 7. As a result, the head 91 is pushed in the direction indicated by the arrow A in the figure, and the connecting piece 9 is elastically deformed. As a result, the insertion portion 90 is deformed in the direction indicated by the arrow B in the figure and is pressed against the inner periphery of the barrel 3. In this way, the connection piece 9 is electrically connected to the back cover 4 and the insertion portion 90 in contact with the back cover 4 and the case 3 to electrically connect the case 3 and the back cover 4 partially. Here, “partially” means that in a part of a region where the body 3 and the back cover 4 are engaged with each other (in this embodiment, a circular region substantially along the outer periphery of the back cover 4). In this example, the body 3 and the back cover 4 are insulated from each other for the most part, but both are electrically connected to the part in contact with the connection piece 9.

  Further, as shown in FIG. 3, the head 91 of the connection piece 9 has wings 92 that are bent toward the back cover 4 side or the movement 7 side (in this embodiment, the back cover 4 side) at both ends thereof. Yes. Thereby, when the head 91 is sandwiched between the convex portion 40 of the back cover 4 and the movement 7, the wing portion 92 is elastically deformed and presses the head 91 against the convex portion 40. Conduction with is surely made.

  Returning to FIG. 2, the effect of providing the connection piece 9 will be described. Considering a case where a potential difference is temporarily generated between the body 3 and the back cover 4 due to static electricity from the outside, a path through which charges are released by the potential difference is from the winding stem 74 through the movement 7. There are a path that is discharged to the back cover 4 through the ground terminal 72 a and a path that is immediately discharged to the back cover 4 via the connection piece 9. At this time, from the short path length and low resistance, it is considered that most of the charges pass through the path via the connection piece 9. Furthermore, since the position of the connecting piece 9 is located opposite to the ground terminal 72a with respect to the center position O of the movement 7, such electric charge hardly flows into the movement 7 via the ground terminal 72a. As a result, most of the electric charge is discharged directly to the back cover 4 without flowing into the movement 7, and no malfunction or the like of the portable radio timepiece 1 is induced. In addition, the body 3 and the back cover 4 are insulated at most positions, and are partially electrically connected only at the connection piece 9, so that no eddy current is generated and the reception sensitivity of the antenna is almost reduced. I won't let you.

  Note that, as in this embodiment, the method of electrically connecting the body 3 and the back cover 4 by the pressing force due to the elastic deformation of the connection piece 9 is reliable, and the portable radio timepiece 1 Even when the back cover 4 is removed for maintenance (for example, replacement of the battery 71), the reconnection is made only by attaching the back cover 4 again. On the other hand, for example, when a conductive paste is partially applied and the body 3 and the back cover 4 are electrically connected, it is difficult to manage the amount of paste applied, and re-application is required during maintenance. .

  FIG. 7 is a diagram showing a modification of the previous embodiment. This figure is an external perspective view showing a state where the connection piece 9 is attached to the movement 7. The present modification is different from the previous embodiment in that the shape of the connection piece 9 is slightly different and the structure of the insertion position display 70c is different.

  In this modification, a structure including a pin 70d and a retaining member 70e is employed as the insertion position display 70c in place of the previous insertion groove 70a and counterbore 70b. The pin 70d is engaged with the engagement hole by being inserted into the engagement hole provided in the connection piece 9, and the retaining member 70e is a washer-like ring provided so that the connection piece 9 does not fall off. .

  FIG. 8 is a perspective view showing an appearance of the connection piece 9 in the modification. The connection piece 9 is the same as the previous embodiment in that it has an insertion portion 90, a head portion 91 continuous with the insertion portion 90 at an obtuse angle, and a wing portion 92 provided at both ends of the head portion 91. . In this modification, an engagement hole 93 is further provided in the head 91. The engagement hole 93 is a hole into which a pin 70 d provided on the base plate 70 of the movement 7 is inserted. The size of the engagement hole 93 is larger than the outer shape of the pin 70d, and when the pin 70d is inserted into the engagement hole 93, the connection piece 9 moves somewhat freely.

  In this way, when the movement 7 and the connection piece 9 are provided with engagement structures that engage with each other, and the connection piece 9 is supported by an appropriate method so that it does not easily fall off the movement 7, the portable radio timepiece 1 When assembling, the movement 7 and the connecting piece 9 can be handled as one. Therefore, the connecting piece 9 which is a fine part is not removed, and the assembly work efficiency is dramatically improved. Of course, the engagement hole 93, the pin 70d, and the retaining member 70e shown here are an example of an engagement structure for handling the movement 7 and the connection piece 9 as one body, and other appropriate structures such as a snap-on mechanism. Can be adopted.

  The above-described embodiment and its modifications are examples for carrying out the present invention, and the present invention is not limited to the specific configuration shown here. Those skilled in the art may make appropriate modifications to these embodiments and their modifications, and change the shape, arrangement, number, material, and the like. The technical scope of the present invention is defined based on the description of the scope of claims, and may include those obtained by appropriately modifying these embodiments and modifications thereof.

  DESCRIPTION OF SYMBOLS 1 Portable radio timepiece, 2 Case, 3 Case, 3a Band fixing part, 4 Back cover, 5 Crown, 6 Push button, 7 Movement, 8 Windshield, 9 Connection piece, 70 Ground plate, 70a Insert groove, 70b Counterbore, 70c Insert Position display, 70d pin, 70e retaining, 71

Battery, 72 Battery retainer, 72a Ground terminal, 73 screw, 74 winding stem, 90 insertion part, 91 head part, 92 wing part, 93 engagement hole.

Claims (3)

A case in which a metal barrel and a metal back cover are fixed to be insulated from each other;
A movement housed in the case;
A conductive connection member for electrically connecting the body and the back cover;
The movement has a ground terminal that is short-circuited with the back cover,
The connection member is a portable radio-controlled timepiece provided on the opposite side to the ground terminal with respect to the center position of the movement.   The portable radio timepiece according to claim 1, wherein the ground terminal is disposed near a periphery of the movement. The connection member is a separate member from the movement,
The portable radio timepiece according to claim 1 or 2, wherein the connection member is inserted between the case and the movement.

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