JPH11153459A - Inner instrument structure of measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the mounting strength of a circuit board in the inner instrument of a plug-in type measuring instrument. SOLUTION: Support pieces 11, 13 are oppositely projected from the back of a front lid member 9 constituting a measuring instrument. Recess parts 17 are formed at the ends of the support pieces 11, 13, and locking holes 21 are formed at intervals and in series between the recess parts 17 and the front lid member 9. Stepped parts 25 which fit into the recess parts 17 are formed on the edge side 23 of a circuit board 15, and lock claws 27 which fit into the locking holes 21 are projected from the side edge 23. The circuit board 15 is supported by pressing the edge side 23 in between the support pieces 11, 13 to lock the lock claws 27 into the locking holes 21 and by fitting the portions of the circuit board 15 near the edge side 23 into the recess parts 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner structure of an instrument, and more particularly to an instrument having a circuit board removably disposed on a rear side of a front cover member of the instrument, for example, an instrument inserted into an instrument case. The improvement of the internal unit structure of

[0002]

2. Description of the Related Art An internal unit structure of this type includes a plurality of circuit boards on which electronic components are mounted, which are detachably mounted on the back side of a front cover member, while being housed in a bottomed box-type instrument case. The instrument case is inserted from the circuit board side, the opening of the instrument case is closed with a front cover member, and the circuit boards are electrically connected to external connection terminals formed at the bottom of the instrument case to produce a product.

In such an internal unit structure, a variety of control functions can be obtained by extracting the front cover member together with the circuit board from the instrument case and appropriately selecting and combining the circuit boards.

[0004]

However, in the above-mentioned internal structure of instruments, the circuit board disposed on the back side of the front cover member can be easily attached and detached, while the front cover member is removed from the instrument case. There is a contradictory requirement that the circuit board must be relatively firmly fixed so that the circuit board does not come off or the fixed position does not move during insertion or insertion.
For this reason, there has been a demand for a structure in which the circuit board can be easily attached and detached and the fixing strength after the attachment is high in the internal structure of instruments.

SUMMARY OF THE INVENTION The present invention has been made under such a circumstance, and is an instrument capable of easily attaching and detaching a circuit board to and from a front cover member, and having good attachment strength and attachment positioning accuracy of the attached circuit board. It is intended to provide an inner unit structure of the present invention.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an inner structure of instruments according to the present invention is provided so as to oppose a front cover member of the instruments at a distance from the rear side of the front cover member. At least one set of supporting pieces protruding so as to form a circuit board, and a circuit board on which the electronic circuit of the instrument is formed and supported by press-fitting an edge between the supporting pieces. A lock claw is formed, a locking hole for locking the lock claw is formed in the support piece, and a concave portion that fits near an edge of the circuit board is formed at a tip end of the support piece, and the circuit board has Are press-fitted between the support pieces to lock the lock claws in the locking holes, and the recesses are fitted around the periphery of the circuit board and supported.

Further, according to the present invention, a guide groove which passes through a locking hole from a concave portion of the support piece and which is in contact with the circuit board is provided on the support piece and is engaged with the circuit board from the concave portion. It is preferable to form a guide groove for guiding to the stop hole. Further, the present invention may be configured such that a step formed on an edge of the circuit board fits into the recess of the support piece.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the internal structure of instruments according to the present invention, which is shown together with a plug-in type instrument for convenience.

In FIG. 1, an instrument case 1 has a conventionally known configuration, and is formed in a box shape with a bottom using a synthetic resin or a metal material. On one end face of the instrument case 1, a flange 5 is integrally formed on the outer periphery as a front open portion 3, and an external connection terminal (not shown in FIG. (See reference numeral 37 in the middle).

The inner unit 7 has a front opening 3 in the instrument case 1.
It is inserted from the side, has a display unit and an operation unit (not shown) (see reference numerals 33 and 35 in FIGS. 4 and 5 described later), and is formed to have almost the same outer dimensions as the outer periphery of the flange 5. The front cover member 9, upper and lower support pieces 11 and 13 protruding facing each other on the back side, and a plurality of circuit boards 15 supported so as to be sandwiched between the upper and lower support pieces 11 and 13. Have. The present invention is characterized by the configuration of the support pieces 11, 13 and the circuit board 15 supported therebetween.

That is, as shown in FIGS. 2 to 4, each of the support pieces 11 and 13 has a plurality of (three in FIG. 4) recesses 17 at the tip end thereof at equal or arbitrary intervals. The upper and lower concave portions 17 are formed in the same positional relationship in the upper and lower directions, and are formed to be equal to or slightly narrower in thickness than the circuit board 15, and the circuit board 15 is inserted or press-fitted as described later. A guide groove 19 having a thickness or a slightly wider width is formed on the surface of the support pieces 11 and 13 that comes into contact with the circuit board 15 from the recess 17 to the vicinity of the front cover member 9. An engagement hole 21 is formed through the guide groove 19 extending to the lid member 9.

On the other hand, the circuit board 15 supported between the support pieces 11 and 13 has a step 25 formed by slightly reducing the width between the edges 23 inserted between the support pieces 11 and 13. A locking claw 27 that is fitted into and locked in the locking hole 21 of the support pieces 11 and 13 protrudes from the edge 23 in the middle from the step portion 25 to the tip. The lock claw 27 has an inclined surface 27a or a round surface at the tip end side in the insertion direction, and facilitates insertion of the circuit board 15 as described later.

Then, the circuit board 15
Are inserted into the upper and lower guide grooves 19 of the support pieces 11 and 13, and the lock claws 27 are fitted into the locking holes 21 and locked, while the step portions 25 are fitted into the recesses 17 and the support pieces 11 and 13 are fitted.
It is supported so as to be sandwiched therebetween, and the inner unit structure of the present invention is formed. Accordingly, in the support pieces 11 and 13, the dimension between the concave portion 17 and the locking hole 21 and the distance between the lock claw 27 of the circuit board 15 and the step portion 25 are substantially equal.

[0014] The inner structure of the instrument of the present invention is formed on the edges 23 of the circuit board 15 as shown in FIGS. 4 and 2B.
Are aligned with the upper and lower guide grooves 19 of the support pieces 11, 13, and FIG.
The support pieces 11 and 13 are expanded and deformed as shown in FIG.
2A, the locking claw 27 is fitted into the locking hole 21 and locked, as shown in FIG.
7 and supported so as to be sandwiched between the support pieces 11 and 13.

In FIGS. 4 and 5, reference numeral 33 denotes a display unit such as a liquid crystal display for displaying the operation / setting state of the instruments, and reference numeral 35 denotes an operation unit such as a touch switch for operating the instruments. . As shown in FIG. 5, such an inner unit 7 of the present invention is inserted into the instrument case 1 from the front opening portion 3 side, and as shown in FIG. The part 3 is closed with a front cover member 9 and is detachably fixed by a suitable fixing means (not shown), and is commercialized as a plug-in type instrument. Reference numeral 37 in FIG. 5 denotes an external connection terminal fixed through the bottom of the instrument case 1. In addition, the support piece 1
When removing the circuit board 15 from the first and the first 13, the leading ends of the supporting pieces 11 and 13 are lifted using a suitable jig (not shown) (see FIG. 2C), and the locking of the locking claw 27 with the locking hole 21 is performed. Just remove and pull out.

Incidentally, this plug-in type instrument is shown in FIG.
As shown in the figure, the panel 29 is inserted into the mounting hole 31 of the panel 29 from the front side, that is, from the external connection terminal side (rear side), and is fixed to the flange 5 of the instrument case 1 by clamping it between the flange 5 and the clamp. Is done. In the internal structure of the instrument configured as described above, the recesses 17 are formed at the tips of the support pieces 11 and 13 formed on the back side of the front cover member 9, and the guide groove extends from the recess 17 to the vicinity of the front cover member 9. 19
And a locking hole 21 is formed in the middle of the guide groove 19, while the circuit board 15 has a step 25
And a locking claw 27 is protruded in the middle from the step portion 25 to the front end, and the edges 23 of each other are
13 and the lock claws 27.
Into the locking hole 21 to be locked.
The circuit board 15 was inserted between the support pieces 11 and 13 so as to be sandwiched therebetween.

Therefore, as compared with a configuration in which the lock claw 27 is fitted into the locking hole 21 and locked to hold the circuit board 15 between the supporting pieces 11 and 13, the supporting strength is greatly improved and the fixing position is also improved. Be accurate. That is, in a configuration in which the lock claw 27 is simply inserted into and locked by the locking hole 21 and the circuit board 15 is sandwiched and supported between the support pieces 11 and 13, a certain fixing force can be exerted for the pulling force of the circuit board 15. However, it tends to be weak against bending in a direction intersecting with the circuit board 15, and there is a problem that the circuit board 15 comes off.

In this regard, in the internal structure of the instrument of the present invention,
The step 25 of the circuit board 15 corresponds to the recess 17 of the support pieces 11 and 13.
Since it is fixed so as to be wrapped or sandwiched in between, it is extremely strong against bending in a direction intersecting with the circuit board 15, and the fixing strength is improved. Moreover,
The circuit board is fixed at the two places of the locking holes 21 and the recesses 17 which are separated from the support pieces 11 and 13, so that the circuit board 1
The positioning accuracy of No. 5 is also accurate.

By the way, in the above-described embodiment of the present invention, the guide groove 19 for slidingly guiding the support pieces 11 and 13 on the surface of the support pieces 11 and 13 which contacts the circuit board 15 has been described. In the present invention, it is not essential depending on the fixing strength of the circuit board 15 and the degree of assembly, and can be arbitrarily configured according to the purpose. Also, the support pieces 11 and 13 protruding from the back side of the front cover member 9 do not need to be one each, and are set as one set of the support pieces 11 and 13 for one or a plurality of circuit boards 15. A plurality can be provided. However, even in the case of providing a plurality of such pieces, it is necessary to form the support pieces 11 and 13 so as to be paired up and down, and it is sufficient to provide at least one or more sets.

Further, in the above-described embodiment, the step portion 25 is provided by narrowing the space between the edges 23 of the portion of the circuit board 15 inserted between the support pieces 11 and 13 to provide the step portion 25. Although it fits into the concave portions 17 of the eleventh and thirteenth, the present invention is not limited to this. In short, it is sufficient if the vicinity of the edge 23 of the circuit board 15 fits into the concave portion 17 of the support pieces 11 and 13. For example, it is also possible to provide a convex portion (not shown) that fits into the concave portion 17 of the support pieces 11 and 13 like the lock claw 27 to form a step portion. However, it is easier to manufacture the circuit board 15 and to further improve the fixing strength when the step portion 25 is provided by forming the space between the edges 23 to be narrower than when projecting the convex portion.

[0021]

As described above, the inner structure of the instrument according to the present invention has a structure in which the circuit board is supported so as to be sandwiched between supporting pieces protruding from the rear side of the front cover member constituting the instrument. A lock claw is formed on the edge of the circuit board, a locking hole for locking the lock claw is formed on the support piece, and a concave portion that fits near the edge of the circuit board is formed at the tip of the support piece. Then, the circuit board is press-fitted between the supporting pieces to lock the locking claws in the locking holes, and at the same time, the vicinity of the edge of the circuit board is inserted into the recess so as to be clamped. The strength is good, the positioning accuracy is good, and the circuit board can be easily attached and detached. Further, in the configuration in which the guide groove is formed in the circuit board in the support piece, if the circuit board is inserted along the guide groove, the lock claw is automatically locked in the locking hole and the recess is formed in the recess. The vicinity of the edge of the circuit board is fitted, and mounting is extremely simple. Further, in the configuration in which the step formed on the edge of the circuit board is fitted in the recess of the support piece, the manufacture of the circuit board is simple and the fixing strength is further improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the internal structure of instruments according to the present invention together with a plug-in type instrument (II in FIG. 3).
It is a cross section and is partially shown in a side view. ).

FIG. 2 is a schematic diagram showing a relationship between a support piece and a circuit board in FIG. 1;

FIG. 3 is a view showing the back side of the front cover member of FIG. 1;

FIG. 4 is a perspective view of a main part showing a relationship between a front cover member and a circuit board in FIG. 1;

FIG. 5 is a perspective view illustrating an assembling process of a plug-in type instrument using the inner device of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Instrument case 3 Front opening part 5 Flange 7 Inner unit 9 Front lid member 11, 13 Supporting piece 15 Circuit board 17 Depression 19 Guide groove 21 Locking hole 23 Edge 25 Step 27 Lock claw 27a Slope 29 Panel 31 Mounting hole 33 Display Section 35 Operation section 37 External connection terminal

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Norio Hirota 5-16-6 Kugahara, Ota-ku, Tokyo Inside Rika Kogyo Co., Ltd.

Claims (3)

[Claims] 1. A front cover member of an instrument, at least one or more sets of support pieces protruding from a rear side of the front cover member so as to face each other, and an electronic circuit of the instrument is formed. A circuit board having an edge press-fitted between the support pieces and supported, wherein a lock claw is formed on the edge of the circuit board, and the lock piece is engaged with the support piece. A locking hole to be stopped is formed, and a concave portion which fits near an edge of the circuit board is formed at a tip end of the support piece, and the circuit board is press-fitted between the support pieces to lock the lock claw. An inner instrument structure of an instrument, wherein the inner instrument is supported by being fitted to a stopper hole and fitted in a vicinity of an edge of the circuit board in the recess. 2. A guide groove passing through the locking hole from the concave portion on the contact surface side of the supporting piece with the circuit board, wherein the circuit board is fitted and inserted into the locking hole from the concave portion. 2. The internal structure of instruments according to claim 1, wherein a guide groove for guiding to the instrument is formed. 3. The internal structure of an instrument according to claim 1, wherein a step formed on an edge of the circuit board fits into a concave portion of the support piece.