JPH056541Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention is applicable to electrical circuits and other objects under test,
This relates to circuit meters that measure resistance, current, voltage, etc.

[Prior Art] A circuit meter usually has a main body formed of a box-shaped panel and a case, and is covered with a carrying case to protect the main body and make it convenient to carry.
The inside of the main body houses instruments, printed circuit boards, batteries, range switching switches, etc., and the surface has a scale plate or digital display section, dial scale, selector switch knob, power switch, and test rod lead wires. Set the range to be measured by rotating the selector switch using the knob, insert the lead wire of a separately prepared test rod into the terminal hole, and insert the test pin. It comes into contact with both ends of the part to be measured and reads the instructions from the pointer or the numbers on the digital display.

[Problems to be solved by the invention] In the circuit meter described above, the main body and carrying case are prepared separately and both are used together, which not only increases the overall size and weight but also increases the cost. There was a problem that the amount of water was also increasing. Furthermore, since digital circuit meters are battery-powered, it is common for people to forget to turn off the power switch, resulting in wasted battery power.

The present invention was made in order to solve the above problems, and aims to provide a circuit meter that is small and lightweight, and there is no possibility of forgetting to turn off the power.

[Means for Solving the Problems] The present invention has been made to solve the above problems and achieve the purpose. A printed circuit board, a panel, etc. are housed in the panel, and a dial for a range changeover switch is disposed in a corner of the panel.The dial is provided with a knob projecting outward from its outer periphery, and the dial is configured to be set to a specific range. The present invention provides a circuit meter configured such that the knob is located within the corner of the case only when the knobs are aligned.

[Function] When the dial is in a position other than a specific range, the cover cannot be closed because the knob is on the peripheral wall of the case. When the dial is aligned with a specific range position, the knob is located within the corner formed by the peripheral wall of the case, allowing the cover to be closed.

[Example] Fig. 1 is a perspective view of an example of the casing according to the present invention;
Fig. 2 is a plan view of an embodiment of the present invention showing the case with the cover open, and Fig. 3 is an exploded perspective view thereof.This embodiment shows an example in which the present invention is implemented in a digital circuit meter. be.

In the figure, 1 is the housing, 11 is the case, 1
Reference numeral 2 denotes a cover that is integrally connected to the case 1 via a thin wall portion, and has protrusions 13 to 15a provided on its inner surface. 2 is a printed circuit board having a wiring pattern, a large number of electronic components, a conductive pattern 21 of a changeover switch, a digital display section 24, and the like. 3
is a panel with a solar cell 3 that charges the built-in battery.
9, a mounting portion 32 for the dial 4 of the changeover switch, etc. are provided. 5 is a display window 51 of the digital display section 24, a window 52 of the solar cell 39,
This is a front panel provided with an arc-shaped cutout 53 that matches a part of the outer periphery of the dial 4 of the changeover switch. Reference numeral 6 indicates a lead reel that is coupled to the protrusion 13 provided on the cover 12 of the housing 1; 7 and 7a indicate test rods having test pins 71 and 71a at their tips;
Lead wires 2 and 72a have one end connected to the printed circuit board 2 and the other end connected to the test pins 72 and 72a, respectively.

In the circuit meter constructed as described above, the present invention has a particular feature in the structure of the range changeover switch, which will be explained below.

4A is a plan view of the dial 4 of the changeover switch, FIG. 4B is a sectional view taken along the line O-O, and FIG. 4C is a rear view thereof.
In the figure, reference numeral 41 denotes a knob that is provided on one side of the upper surface of the dial 4 so as to protrude from the outer periphery of the dial 4, and the upper surface has irregularities formed to prevent slipping. In the embodiment, this knob 41 is formed into a circular shape, and its outer circumference is the center of the dial 4 and the knob 4.
It is provided at a position that is almost in contact with the fold line of the dial 4 that is orthogonal on the line OO connecting the center of the dial 1, that is, at a position where a part of its outer periphery protrudes outward from the outer periphery of the dial 4.

Reference numeral 42 denotes a cylindrical protrusion provided on the back surface of the dial 4. On the side wall of the protrusion 42, protrusions 43a to 43a are provided on the O-O line on the opposite side of the knob 41 and on both sides thereof.
A locking portion 43 consisting of a recess 43f and a recess is provided (within a range of 120° in the embodiment), and a cutout portion 44 is provided on the opposite side wall of the locking portion 43, facing the locking portion 43.
is provided, and step portions 45, 45a are formed at both ends thereof.

47a to 47c are recesses 46 provided in the protrusion 42
A brush disposed inside slides into contact with the conductive pattern 21 provided on the printed circuit board 2. 48 is the protrusion 4
A shaft 49 protruding from the center of 2 is an index.

FIG. 5 is a plan view of the mounting portion 32 of the dial 4 provided on the panel 3. Reference numeral 33 denotes a hole formed through the panel 3 so that the protrusion 42 of the dial 4 can fit therein, and a stopper 34 that engages with the cutout 44 of the protrusion 42 is protruded from one side. 35 is hole 3
It is a recess formed around the panel 3 and lower than the surface of the panel 3, and is formed in a size that allows the dial 4 to fit therein. Elastic arms 36 and 36a are formed by a groove 38 on the opposite side of the stopper 34, and engagement parts 37 and 37a are formed at the tips of the arms, respectively. The protrusions 43a to 43f of the provided locking portion 43 are engaged, thereby forming a click mechanism.

To assemble such a changeover switch, the dial 4 is fitted into the mounting part 32 of the panel 3 with the locking part 43 on the elastic arms 36, 36a side, and the shaft 48 is connected to the conductive pattern 21 of the printed circuit board 2. It is inserted into the hole 22 provided in the center of the printed circuit board 2, and the stopper 23 is fitted into the groove 48a of the shaft 48 on the back surface of the printed circuit board 2, so that it is rotatably mounted. At this time, stopper 3
4 is a cutout portion 44 provided on the protrusion portion 42 of the dial 4;
located within.

In the above-mentioned changeover switch, when the dial 4 is rotated with a finger on the knob 41, one of the convex parts 43a to 43f (for example, 43d) of the locking part 43 moves to the engaging part 37 of the elastic arms 36, 36a. , 37a and stops, and when the dial 4 is further rotated, the convex portion 43d comes out from between the engaging portions 37, 37a, and the next convex portion (for example, 43e) engages with the engaging portions 37, 37a. Go in between and stop again. In this way, the dial 4 can be rotated left and right until the stepped portion 45 or 45a of the cutout portion 44 hits the stopper 34. Therefore, by attaching range symbols on the front panel 5 corresponding to the stop positions of the dial 4, the desired range can be easily selected.

An example of the assembly order of the circuit meter according to the present invention will be explained with reference to FIGS. 1 to 3 again. First, panel 3
A solar cell 39, a changeover switch dial 4, etc. are incorporated into the board, and the printed circuit board 2 is integrally connected thereto, and a front panel 5 is mounted thereon. On the other hand, the lead reel 6 is connected to the protruding part 13 provided on the cover 12 of the housing 1, and the lead wires 72, 72a are wound thereon, and the test rods 7, 7a are attached to the protruding parts 14, 14a and 15, 15a of the cover 12. If you hold each, the first
It is assembled as shown in the figure.

To measure the electrical characteristics of the object to be measured, turn the dial 4 to set the desired range, remove the test rods 7, 7a from the cover 12, and connect the lead wire 7.
2, 72a are unwound from the lead reel 6, and the test pins 71, 71a are brought into contact with the object to be measured for measurement. When the measurement is finished, turn the dial 4 and set the index 49 to OFF to turn off the power circuit, wind the lead wires 72 and 72a around the lead reel 6, and hold the test rods 7 and 7a on the cover 12. When the cover 12 is closed, everything including the test rods 7, 7a and lead wires 72, 72a are stored in the housing 1, and the circuit meter becomes a compact box.

By the way, in the present invention, when the dial 4 is turned and the indicator 49 is aligned with the OFF symbol provided on the front panel 5, the dial 4 is turned off when the power circuit is turned off.
The knob 41 is located at the corner 17 of the case 11. That is, as shown in FIG. 6, the front panel 5 is provided with range symbols A to F, for example, corresponding to the stop positions of the dial 4 by the click mechanism. is rotated to align the index 49 with either of them.

Now, when the index 49 is set at A, the knob 41 is at the 41A position, and when the index 49 is set at B to F in the same way, the knobs 41 are at the 41A position.
Located from 1B to 41F. Therefore, indicator 49
The knob 41 is located within the corner 17 formed by the peripheral wall 16 of the case 1 only when the indicator 49 is aligned with D, but when the indicator 49 is aligned with A, B, C, E, and F,
Since a portion of each knob 41 is located on the peripheral wall 16, the cover 12 cannot be closed.

The present invention is configured so that the power circuit is turned off when the indicator 49 of the dial 4 matches the above D, so if the power circuit is not turned off, the knob 4
1 interferes and the cover 12 cannot be closed,
Therefore, there is no risk of forgetting to turn off the power supply circuit.

In addition, in the case of a pointer display type (analog type) circuit meter, when the indicator 49 of the dial 4 is set to the above D, the movable part of the meter is electrically short-circuited, creating a damping effect against vibration and protecting the meter. do.

In the above explanation, the knob provided on the dial 4 of the change-over switch is circular, but it may be polygonal or other shape, and the click mechanism, brush, etc. of the change-over switch are also limited to the above embodiment. It is not a fixed value and can be changed as appropriate. Furthermore, although the case 11 and the cover 12 are integrally connected through a thin portion, they may be made separately and connected detachably.

Note that in order to make the circuit meter more compact, the range symbol provided on the front panel may be printed on the edge of the solar cell.

[Effects of the invention] As is clear from the above explanation, in this invention, the cover cannot be closed unless the dial is adjusted to a specific range, so there is no risk of forgetting to turn off the power circuit, and therefore the built-in battery can be used for a long time. In addition, in a pointer display type circuit meter, by matching the dial with a specific range, the movable part of the meter can be electrically shorted and protected from vibration, which has a great practical effect.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the external appearance of a circuit meter according to the present invention, Fig. 2 is a plan view showing the cover in an open state, Fig. 3 is an exploded perspective view of an embodiment of the invention, and Fig. 4 a is a Plan view of the embodiment of the dial, b its O-O
5 is a plan view of an embodiment of the dial mounting portion provided on the panel, and FIG. 6 is an explanatory diagram of the operation of the main parts of the present invention. DESCRIPTION OF SYMBOLS 1... Housing, 11... Case, 12... Cover, 13-15a... Projection, 16... Peripheral wall, 1
7... Corner, 2... Printed circuit board, 21... Conductive pattern of changeover switch, 3... Panel, 32...
...Dial mounting part, 34...Stopper, 36,
36a...Elastic arm, 37, 37a...Engaging portion, 4
... Dial, 41 ... Knob, 42 ... Protrusion, 43 ... Locking part, 43a to 43f ... Convex part,
44... Resection part, 47a, 47c... Brush, 4
8... Axis, 49... Index, 5... Surface panel, 6
... Lead reel, 7, 7a ... Test rod, 7
2,72a...Lead wire.

Claims (1)

[Scope of Claim for Utility Model Registration] It has a casing consisting of a case and a cover, a printed circuit board, a panel, etc. are housed in the case of the casing, and a dial for a range changeover switch is disposed in the corner of the panel. The circuit meter is characterized in that the dial is provided with a knob protruding outward from its outer periphery, and the knob is positioned within a corner of the case only when the dial is aligned with a specific range. .