Electronic circuit unit

Abstract

Provided is an electronic circuit unit that can be replaced without restricting the diameter of the tip of a screwdriver and without damaging a housing, while preventing a screw that fastens a circuit board and a substrate together from falling off. The electronic circuit unit comprises a combination screw (10), a circuit board (20), a housing (30), an anti-loosening rib (40) and a substrate (50). A housing (30) covering the circuit board (20) has a counter bore (31) which is larger than the diameter of a screw head (11) of the combination screw (10) and deeper than the height of the screw head (11). The anti-loosening rib (40) has an inner diameter smaller than a diameter of a gasket (13) of the combination screw (10) and larger than a diameter of a screw head (11), and is arranged at a height such that the combination screw (10) stops at a position where a screw tip of the combination screw (10) does not disengage from a through hole (22) of the circuit board (20). The base plate (50) has a female threaded portion (51) to which the combination screw (10) is fastened.

Description

Technical Field

[0001] The present invention relates to an electronic circuit unit having an electronic circuit, and more particularly, to an electronic circuit unit having a structure for preventing screws from falling off. Background Art

[0002] A glass antenna mounted on the front glass or the rear glass is known as one of vehicle antennas. Specifically, the glass antenna has a structure in which a wire used as an antenna element is provided in the form of a seal and attached to the glass or embedded in the glass. The glass antenna has a terminal used as a feeding point, which is connected to a coaxial cable from a radio receiver or the like. There are various types of connectors for such a connection. For example, an electronic circuit unit such as an amplifier holder is known, which has a structure in which an electronic circuit such as an amplifier circuit is incorporated into a connector. This type of electronic circuit unit is fixed facing the glass with the aid of a double-sided tape.

[0003] Such an electronic circuit unit is configured to be removable from the glass so that it can be replaced when an amplifier circuit therein fails, etc. For example, Patent Document 1 discloses a circuit module having a structure in which a module body of a circuit board in a base plate of the circuit module is fixed to the base plate by screws to engage with the glass. When it is necessary to replace the circuit board, the screws are removed after the housing locked to the base plate is removed, thereby making it possible to easily remove the circuit board from the base plate.

[0004] However, when an electronic circuit unit has a structure that is completely covered by a shell (as disclosed in Patent Document 1), it is necessary to remove the shell from the base plate when the electronic circuit unit is fixed to the glass, so the operability is poor. In order to cope with this situation, in Patent Document 2, a screw member operating hole having a diameter smaller than the diameter of the screw head but larger than the diameter of the end of the driver engaged with the screw head is formed in the shell so that the screw can be rotated when the shell is fixed to the circuit board. In Patent Document 2, the screw member operating hole has a diameter smaller than the diameter of the screw head, thereby preventing the screw from falling off, thereby improving the operability during screw connection. In addition, the screw member operating hole has a thin-walled portion, which is configured to be damaged so that the screw can be completely separated from the substrate.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2008-263537

[0008] Patent Document 2: Japanese Patent Application Publication No. 2009-044334 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] However, the screw member operation hole described in Patent Document 2 has a diameter smaller than the diameter of the screw head and larger than the diameter of the tip of the driver engaged with the screw head, so there is a limit to the tip of the driver to be used. In other words, only a driver with a relatively thin tip can be used. In addition, in order to separate the screw from the substrate, it is necessary to damage the housing.

[0011] Therefore, an electronic circuit unit is desired which allows a screw to be easily removed therefrom when necessary while preventing accidental falling out of the screw, has no restrictions on the diameter of the tip of the driver to be used, and allows the reuse of its housing.

[0012] The present invention is made in view of the above situation, and its purpose is to provide an electronic circuit unit that can prevent the screws used to fasten the circuit board and the substrate from falling off, has no restriction on the diameter of the end of the driver to be used, and allows the circuit board to be replaced without damaging the housing.

[0013] Solutions for solving problems

[0014] In order to achieve the above-mentioned object of the present invention, the electronic circuit unit according to the present invention includes: a screw assembled with a washer, which has a screw head and a screw rod and is assembled with a washer; a circuit board, which has a through hole and is installed with an electronic circuit, and the screw rod of the screw assembled with the washer passes through the through hole; a shell, which covers the circuit board and has a countersunk hole, the countersunk hole has a diameter larger than the diameter of the screw head of the screw assembled with the washer and has a depth larger than the height of the screw head; a screw-fall-prevention rib, which is positioned inside the countersunk hole formed in the shell, has an inner diameter smaller than the diameter of the washer of the screw assembled with the washer and larger than the diameter of the screw head, and is arranged at the following height, at which the screw assembled with the washer stops at a position where the screw end of the screw assembled with the washer does not disengage from the through hole of the circuit board; and a substrate, which is assembled to the shell to define an internal space and has a female threaded portion, and the screw assembled with the washer is engaged with the female threaded portion for fixing the circuit board to the substrate in a detachable manner.

[0015] The screw-off preventing rib may be arranged at a height at which a screw tip of the washer-assembled screw can move to a position that does not reach the female thread portion when the base plate is assembled to the housing.

[0016] The screw-fall-off preventing rib may be arranged at a height at which the screw assembled with the washer is stopped at a position where a screw tip of the screw assembled with the washer stays within a thickness of the through hole of the circuit board.

[0017] The housing may have a reinforcement frame fixed inside thereof, and the reinforcement frame is fixed to the circuit board.

[0018] The reinforcement frame may have a frame through hole having an inner diameter smaller than a diameter of the washer of the washer-assembled screw and larger than a diameter of the screw head, and the frame through hole serves as the screw-fall-off preventing rib.

[0019] The screw-fall-off preventing rib may be arranged on an inner side wall of the counterbore of the housing.

[0020] The electronic circuit unit may be an amplifier holder attached facing an electrode of a glass antenna, and the female thread portion of the substrate may be a female thread portion having a spring terminal contacting the electrode of the glass antenna to be electrically connected thereto.

[0021] Advantageous Effects of the Invention

[0022] The electronic circuit unit according to the present invention is advantageous in that it can prevent screws for fastening a circuit board and a substrate from falling off, is not limited by the diameter of the tip of a driver to be used, and enables replacement of the circuit board without damaging the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic perspective view for explaining the entire configuration of an electronic circuit unit according to the present invention.

[0024] Figure 2 is a schematic partial cross-sectional side view for explaining states before and after screw tightening when assembling the electronic circuit unit according to the present invention.

[0025] Figure 3 is a schematic perspective view for explaining the entire configuration of another example of the electronic circuit unit according to the present invention.

[0026] Figure 4 is a schematic partial cross-sectional side view for explaining an example of providing a screw-fall-off preventing rib to a reinforcement frame of an electronic circuit unit according to the present invention. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments for practicing the present invention will be described using illustrated examples. Figure 1 is a schematic perspective view for explaining the entire configuration of an electronic circuit unit according to the present invention. Figure 2 is a schematic partial cross-sectional side view for explaining states before and after screw tightening when assembling an electronic circuit unit according to the present invention; Figure 2 (a) shows the state before the screw is tightened, while Figure 2(b) shows the state after the screw is tightened. Figure 1 The same reference numerals in the figure denote the same parts. The following describes an example in which an electronic circuit unit is used as an amplifier holder, which is attached facing electrodes 2 and 3 of a glass antenna 1. However, the present invention is not limited thereto, and can be applied to any type of electronic circuit unit as long as it has a structure to prevent screws from falling off.

[0028] like Figure 1 and Figure 2 As shown, the electronic circuit unit according to the present invention mainly includes a screw 10 assembled with a washer, a circuit board 20, a housing 30, a screw-fall-preventing rib 40, and a substrate 50.

[0029] The screw 10 assembled with a washer has a screw head 11 and a screw rod 12, and is assembled with a washer 13. More specifically, the washer 13 has a diameter greater than the diameter of the screw head 11. The washer 13 may be a flat washer or a spring washer. Alternatively, the washer 13 may be formed by combining a flat washer and a spring washer. The screw 10 assembled with a washer may be appropriately selected to have the following length of the screw rod 12, that is, when the housing 30 described later is assembled to the substrate 50 and fastened to the substrate 50 by the screw 10 assembled with a washer, the screw end of the screw 10 assembled with a washer does not penetrate the substrate 50. That is, it may have the following length: the screw end of the screw 10 assembled with a washer does not protrude from the rear surface of the substrate 50. Although two screws 10 assembled with washers are used in the illustrated example, the number of screws 10 assembled with washers used in the electronic circuit unit is not particularly limited in the present invention.

[0030] The circuit board 20 is a board on which an electronic circuit 21 is mounted. The electronic circuit 21 is, for example, an amplifier circuit or a filter circuit. In addition, the circuit board 20 has a through hole 22, through which the screw 12 of the screw 10 assembled with a washer passes. That is, the through hole 22 is formed at a position where the screw 12 passes through the circuit board 20 when the screw 10 assembled with a washer is tightened. In addition, when the screw 10 assembled with a washer is used to electrically connect the circuit board 20 and the electrodes 2 and 3 of the glass antenna 1, an annular conductive land 23 can be provided as needed so as to enable conduction between the screw 10 assembled with a washer and the electronic circuit 21 of the circuit board 20. Specifically, electricity reaches the screw 10 assembled with a washer from the annular conductive land 23 through the washer 13.

[0031] The housing 30 covers the circuit board 20. The housing 30 has a countersunk hole 31. The countersunk hole 31 has a diameter greater than the diameter of the screw head 11 of the screw 10 assembled with the washer, and has a depth greater than the height of the screw head 11. Specifically, as Figure 2As shown, the counterbore 31 may have a depth that does not allow the screw head 11 to protrude from the housing 30 after the screw is tightened. In addition, the counterbore 31 may be formed to have a cylindrical side wall. That is, the counterbore 31 has a bottomless cylindrical shape. Since the counterbore 31 has a diameter greater than the diameter of the screw head 11, the driver that engages with the screw head 11 is not limited to a thin driver, but a standard type can be used. In addition, the housing 30 may have a locking claw 32 so as to be locked to the circuit board 20. By means of the locking claw 32, the housing 30 is fixed to the circuit board 20. The substrate 50 may also have a locking claw. As shown in FIG. Figure 2 As shown, the side wall of the counterbore 31 is configured so that its lower end abuts against the circuit board 20. This can prevent dust and dirt from entering the interior of the housing 30 through the counterbore 31.

[0032] The screw-fall-preventing rib 40 is provided to prevent the screw 10 assembled with the washer from falling off from the housing 30. The screw-fall-preventing rib 40 is formed inside the counterbore 31. Specifically, as Figure 2 As shown, the screw-fall-preventing rib 40 is composed of an inner annular rib structure formed on the inner side wall of the counterbore 31 of the housing 30. The screw-fall-preventing rib 40 has an inner diameter that is smaller than the diameter of the washer 13 of the screw 10 assembled with the washer, and is larger than the diameter of the screw head 11. That is, the screw-fall-preventing rib 40 is composed of an annular rib having a through hole having .... Figure 2 When the screw 10 with a washer is inserted into the lower part of the housing 30, the screw head 11 is allowed to pass through the screw-preventing rib 40, but the washer 13 is not allowed to pass. In the case of this structure, the screw 10 with a washer can be prevented from falling off from the housing 30.

[0033] In addition, the screw-fall-off preventing rib 40 is arranged at a height where the screw 10 assembled with the washer stops at a position where the screw tip of the screw 10 assembled with the washer does not come off from the through hole 22 of the circuit board 20. That is, even in a state where the screw 10 assembled with the washer is arranged at the maximum height (at Figure 2 In the state shown in (a) of FIG. 1 ), the positional relationship between the washer 13 and the screw-fall-preventing rib 40 can also be adjusted to prevent the screw tip from being disengaged from the through hole 22. This structure can prevent the operability from being deteriorated in the subsequent tightening work when the screw tip of the screw 10 assembled with the washer is disengaged from the through hole 22 and the screw 10 assembled with the washer is tilted inside the counterbore 31. Figure 2In the example shown in (b), the screw-fall-preventing rib 40 is arranged at a height such that the screw 10 assembled with the washer stops at a position where the screw end of the screw 10 assembled with the washer stays within the thickness of the through hole 22; however, the present invention is not limited to this, and the screw-fall-preventing rib 40 can be arranged at a height such that the screw 10 assembled with the washer stops at a position where the screw end protrudes from the through hole 22, as long as the screw end does not detach from the through hole 22.

[0034] The substrate 50 is assembled to the housing 30 to define an internal space. That is, the substrate 50 is assembled to the lower opening of the housing 30. The substrate 50 has a female threaded portion 51. The female threaded portion 51 is engaged with the screw 10 assembled with a washer so that the circuit board 20 is fixed to the substrate 50 in a detachable manner. In the example shown, the electronic circuit unit is configured as an amplifier holder for the glass antenna 1, and the female threaded portion 51 is provided with a spring terminal 52, which contacts the electrodes 2 and 3 of the glass antenna 1 to be electrically connected thereto. The female threaded portion 51 may be insert-molded in the substrate 50. The substrate 50 thus configured may be attached to glass using a double-sided tape 55 or the like.

[0035] As described above, the positional relationship between the washer 13 and the screw-off preventing rib 40 is adjusted so as not to allow the screw tip to escape from the through hole 22. In addition, the screw-off preventing rib 40 may be arranged in the following manner. Figure 2 As shown, the screw-fall-off preventing rib 40 can be arranged at a height such that the screw tip of the screw 10 assembled with the washer can be moved to a position that does not reach the female thread portion 51 when the base plate 50 is assembled to the housing 30. Specifically, the screw-fall-off preventing rib 40 is arranged at a position such that the screw tip of the screw 10 assembled with the washer is moved to a position that does not reach the female thread portion 51 in a state before the screw 10 assembled with the washer is screwed into the female thread portion 51 (i.e., before the screw 10 assembled with the washer is screwed into the female thread portion 51). Figure 2 In the state shown in (a) of FIG. 5 ), the screw 10 assembled with the washer is allowed to be lifted to a position where the screw end of the screw 10 assembled with the washer does not reach the female thread portion 51. That is, the position where the screw end does not disengage from the through hole 22 and the screw end does not reach the female thread portion 51 refers to a position within the thickness of the through hole 22 of the circuit board 20. Therefore, the screw-fall-off prevention rib 40 can be arranged at a height such that the screw 10 assembled with the washer stops at a position where the screw end of the screw 10 assembled with the washer stays within the thickness of the through hole 22 of the circuit board 20. When the substrate 50 is assembled to the housing 30, when the screw end of the screw 10 assembled with the washer protrudes to a position where it reaches the female thread portion 51, the assembly therebetween may be hindered; on the other hand, when the screw 10 assembled with the washer is lifted to a position where the screw end does not reach the female thread portion 51, after the substrate 50 is assembled to the housing 30, the screw 10 assembled with the washer can be engaged with the female thread portion 51. This further improves the operability during assembly.

[0036] The thus constructed electronic circuit unit according to the present invention can be assembled in the following manner. The substrate 50 is assembled with the female threaded portion 51 and then attached to the glass using the double-sided tape 55. The screw 10 assembled with the washer is passed through the through hole 22 of the circuit board 20, and the resulting circuit board 20 is covered with the housing 30. When the circuit board 20 is locked to the housing 30, the screw 10 assembled with the washer cannot be disengaged from the countersunk hole 31. In addition, the screw tip cannot be disengaged from the through hole 22. In this state, the housing 30 is assembled to the substrate 50. Then, the screw 10 assembled with the washer is tightened to fix the circuit board 20 to the substrate 50.

[0037] When the electronic circuit unit needs to be replaced, the screw 10 assembled with the washer is loosened, thereby allowing the circuit board 20 to be easily removed from the base plate 50 together with the housing 30. When the reason for replacement is a failure of the circuit board 20, only the circuit board 20 needs to be replaced with a new one, and the housing 30 and the screw 10 assembled with the washer are reusable.

[0038] Used in the following Figure 3 Another example of the electronic circuit unit according to the present invention is described. Figure 3 1 is a schematic perspective view for explaining the entire configuration of another example of the electronic circuit unit according to the present invention. Figure 1 The same reference numerals in the figures represent the same parts. Figure 1 The difference is that a reinforcement frame 35 for reinforcing the housing 30 is additionally provided. The reinforcement frame 35 can be fixed inside the housing 30. That is, the locking claw 32 of the housing 30 can be locked to the reinforcement frame 35. When the reinforcement frame 35 is arranged at a position where the screw 10 assembled with a washer passes through as shown in the figure, a frame through hole 36 can be formed in the reinforcement frame 35. The reinforcement frame 35 can be fixed to the circuit board 20 as needed. The reinforcement frame 35 can be fixed to the circuit board 20 using screws or the like, or can be fixed thereto by clamping the circuit board 20 with a locking portion 37 as shown in the figure. In order to enhance strength, the reinforcement frame 35 thus constructed can be used for the housing 30.

[0039] Furthermore, as described below, the reinforcing frame 35 may be used to provide a screw-fall-off preventing rib. Figure 4 is a schematic partial cross-sectional side view for explaining an example of providing a screw-fall-off preventing rib to a reinforcement frame of an electronic circuit unit according to the present invention; Figure 4 (a) shows the state before the screw is tightened, while Figure 4 (b) shows the state after the screw is tightened. Figure 3 The same reference numerals in the drawings represent the same parts. Figure 2In the example shown, the screw-fall-off prevention rib 40 is composed of an inner annular rib structure formed on the inner side wall of the counterbore 31 of the housing 30. Figure 4 In the example shown, the frame through hole 36 is configured to function as the screw-fall-off preventing rib 40. That is, the frame through hole 36 of the reinforcing frame 35 has an inner diameter smaller than the diameter of the washer 13 of the screw 10 assembled with the washer, and larger than the diameter of the screw head 11. Therefore, as in the case of the example shown above, when the screw 10 is Figure 4 When the screw 10 assembled with the washer is inserted into the lower part of the housing 30, the screw head 11 can pass through the frame through hole 36 used as a rib to prevent the screw from falling off, but the washer 13 cannot pass through the frame through hole 36. This can prevent the screw 10 assembled with the washer from falling off from the housing 30.

[0040] In addition, as in the case of the above-mentioned example, the frame through hole 36 can be arranged at a height so that the screw 10 assembled with the washer stops at a position where the screw end of the screw 10 assembled with the washer does not disengage from the through hole 22 of the circuit board 20, and the frame through hole 36 can be arranged at a height so that when the substrate 50 is assembled to the housing 30, the screw end of the screw 10 assembled with the washer can move to a position without reaching the female threaded portion 51.

[0041] Figure 3 and Figure 4 The assembly method for the electronic circuit unit shown is Figure 1 and Figure 2 The assembly method for the electronic circuit unit shown is basically the same. Figure 1 and Figure 2 The electronic circuit unit shown is different in that the screw 10 assembled with a washer is first made to penetrate the through hole 22 of the circuit board 20, and the reinforcing frame 35 is locked to the resulting circuit board 20. In this state, the housing 30 is fixed to the circuit board 20 by the reinforcing frame 35. In the state where the circuit board 20 is locked with the housing 30, the screw 10 assembled with a washer is prevented from escaping from the counterbore 31. The screw tip is also prevented from escaping from the through hole 22. In this state, the housing 30 is assembled to the substrate 50. Then, the screw 10 assembled with a washer is tightened to fix the circuit board 20 to the substrate 50.

[0042] When the electronic circuit unit needs to be replaced, the screw 10 assembled with the washer is loosened, thereby allowing the circuit board 20 together with the housing 30 and the reinforcement frame 35 to be easily removed from the base plate 50 .

[0043] As described above, the electronic circuit unit according to the present invention can prevent the screws for fastening the circuit board and the substrate from falling off, has no limitation on the diameter of the tip of the driver to be used, and enables replacement of the circuit board without damaging the housing.

[0044] The electronic circuit unit according to the present invention is not limited to the above-described examples, but may be variously modified without departing from the gist of the present invention.

[0045] Description of Reference Numerals

[0046] 1: Glass Antenna

[0047] 2, 3: Electrode

[0048] 10: Assemble the screws with washers

[0049] 11: Screw head

[0050] 12: Screw

[0051] 13: Washer

[0052] 20: Circuit Board

[0053] 21: Electronic circuits

[0054] 22: Through hole

[0055] 23: Annular conductive pad

[0056] 30: Shell

[0057] 31: Countersunk hole

[0058] 32: Locking claw

[0059] 35: Strengthen the framework

[0060] 36: Frame through hole

[0061] 37: Locking section

[0062] 40: Rib to prevent screws from falling off

[0063] 50: Substrate

[0064] 51: Female thread

[0065] 52: Spring terminal

[0066] 55: Double-sided tape

Claims

1. An electronic circuit unit having an electronic circuit, the electronic circuit unit comprising: A screw assembled with a washer, which has a screw head and a screw shaft, and is assembled with a washer; A circuit board having a through hole and mounted with an electronic circuit, wherein the screw rod of the screw assembled with a washer passes through the through hole; a housing covering the circuit board and having a countersunk hole having a diameter greater than a diameter of a screw head of the screw assembled with a washer and having a depth greater than a height of the screw head; a screw-fall-off preventing rib, which is positioned inside the counterbore formed in the housing, has an inner diameter smaller than a diameter of a washer of the washer-assembled screw and larger than a diameter of the screw head, and is arranged at a height at which the washer-assembled screw stops at a position where a screw tip of the washer-assembled screw does not come off from the through-hole of the circuit board; and A base plate is assembled to the housing to define an internal space and has a female threaded portion with which the screw assembled with a washer is engaged, for detachably fixing the circuit board to the base plate.

2. An electronic circuit unit according to claim 1, wherein the screw-fall-off preventing rib is arranged at a height at which a screw tip of the screw assembled with a washer can move to a position that does not reach the female threaded portion when the substrate is assembled to the housing.

3. An electronic circuit unit according to claim 1, wherein the screw-fall-preventing rib is arranged at a height at which the screw assembled with the washer stops at a position where the screw tip of the screw assembled with the washer stays within the thickness of the through hole of the circuit board. 4 . The electronic circuit unit according to claim 1 , wherein the housing has a reinforcement frame fixed inside thereof, and the reinforcement frame is fixed to the circuit board.

5. The electronic circuit unit according to claim 4, wherein the reinforcement frame has a frame through hole having an inner diameter smaller than the diameter of the washer of the screw assembled with the washer and larger than the diameter of the screw head, and the frame through hole serves as the screw-fall-preventing rib. 6 . The electronic circuit unit according to claim 1 , wherein the screw-fall-off preventing rib is arranged on an inner side wall of a counterbore of the housing.

7. The electronic circuit unit according to any one of claims 1 to 6, wherein the electronic circuit unit is an amplifier holder to which an electrode of a glass antenna is attached, and The female screw portion of the substrate is a female screw portion having a spring terminal that contacts an electrode of the glass antenna to be electrically connected thereto.

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