CN1968585B - power supply unit - Google Patents

Abstract

An opening is formed on the housing. Air is caused to flow through the interior of the housing. A panel closes the opening. A printed circuit board is arranged behind the panel inside the housing. A plurality of components mounted on a printed circuit board, wherein said components include control means operable on the front surface of the panel and display means providing visible display. The printed circuit board is accommodated in an airtight container provided in the housing.

Description

power supply unit

technical field

The present invention relates to a power supply unit, and more particularly, to the configuration of a printed circuit board used in the power supply unit.

Background technique

A power supply unit, for example for a welding machine, may have a control panel on its outer surface. An example of a power supply unit having such a control panel is disclosed in Japanese Patent Application Laid-Open Publication No. 2003-136241 (JP 2003-136241A). The power supply device disclosed in JP 2003-136241A includes a control panel on the outer surface of the casing, and the control panel includes: a setter for setting the current and voltage that the power supply can provide, a button for selecting the operation mode of the device switch, and an indicator light to indicate the operating status. It is not explicitly shown in the above publication that the setter, switch and lamp are mounted on a printed circuit board. Such printed circuit boards can be assembled at high density. In this case, the distance between the conductors printed on the circuit board is very small, eg less than 0.5 mm. A high-density assembled printed circuit board is fixed on the rear surface or the inner surface of the control panel. A plurality of openings are formed through the control panel through which operating parts for the setter and the switch and the indicator lamps are exposed, so that the operator can operate the setter and the switch from the outside and confirm the operation status by indication of the lamp.

In order to cool the inside of the housing of the power supply unit, outside air is often sucked into the housing, and, in this case, the two opposing main surfaces of the densely assembled printed circuit board for the control panel are exposed to the air drawn into the housing. the air inside the enclosure.

Power supply units for welding machines are sometimes used in environments where conductive dust and/or corrosive gases are present. Such conductive dust and corrosive gas can enter the casing of the power supply unit and have harmful effects on the printed circuit board inside the casing. In particular, printed circuit boards for control panels are more susceptible to dust and anti-corrosive gases than other printed circuit boards because such printed circuit boards for control panels are assembled at a higher density. The conductive dust attached to the printed circuit board will deteriorate the insulation of the circuit board, and the corrosive gas will corrode the components mounted on the circuit board and printed conductors, which will cause the failure of the power supply device.

It is thus an object of the present invention to protect a printed circuit board for a control panel from the influence of the ambient air on the printed circuit board.

Contents of the invention

According to an aspect of the present invention, a power supply unit includes a housing through which air can flow inside. In order to allow air to flow through the inside of the housing, it is preferable to form an intake port and an exhaust port at different positions in the housing. Furthermore, preferably, a fan is provided within the housing to assist the flow of air through the interior of the housing. An opening is formed in the housing and closed by the panel. The panel can cover the opening from the inside of the housing or from the outside of the housing. A first printed circuit board is disposed behind the panel within the housing. A plurality of components are mounted on the first printed circuit board. Said components include control means operable from the front side of the panel, and display means providing a visual display on the front side of the panel. The control means has a controller for operating the control means, preferably extending outwardly through the panel. The display portion of the display device is preferably arranged on the front side of the panel. The first printed circuit board is accommodated in a sealed container within the housing.

With the above structure of the power supply unit, since the first printed circuit board is located in the airtight container, the first printed circuit board is not in contact with conductive dust and/or corrosive gas contained in the air flowing through the inside of the case. Consequently, neither deterioration of the insulation of the first printed circuit board nor corrosion of components mounted on the first printed circuit board or printed conductors occurs.

The distance between adjacent conductors printed on the first printed circuit board may be small. If any conductive dust adheres to a printed circuit board having conductors separated from each other by a small distance, it will deteriorate the insulation between the conductors. However, according to the present invention, since the first printed circuit board is housed in the airtight container, deterioration of the insulation of the first printed circuit board does not occur.

Preferably, the container includes: a wall unit extending from the inner surface of the panel toward the inside of the housing and having an opening at a distal or innermost end thereof; and a cover closing the opening. Preferably, said wall unit and said panel are formed in one piece. Since the wall unit is formed on the panel, the end of the wall unit on the panel side is closed by the panel, and thus, no additional member is needed to close the end, which simplifies the structure of the power supply.

Said cover closing the rear opening formed by the wall unit may be a second printed circuit board. In this way, it is not necessary to provide a dedicated cover, thereby simplifying the structure of the power supply unit.

A first printed circuit board may be disposed near a rear surface or an inner surface of the panel. A fixing member for fixing the first printed circuit board is provided on the inner surface of the wall unit, and the fixing member preferably extends inwardly towards the outer edge of the rear surface of the first printed circuit board. This configuration eliminates the need for screws or adhesives for fixing the first printed circuit board, which makes the manufacture of the power supply device easier.

Description of drawings

FIG. 1 is a partially omitted longitudinal sectional view of a power supply device according to an embodiment of the present invention.

FIG. 2 is an exploded view of a control panel of the power supply device shown in FIG. 1 .

3 is a partially omitted longitudinal sectional view of a power supply device according to another embodiment of the present invention.

4 is a partially omitted longitudinal sectional view of a power supply device according to yet another embodiment of the present invention.

Detailed ways

A power supply unit for welding according to an embodiment of the present invention is shown in FIGS. 1 and 2 . As seen from FIG. 1, the power supply unit has a housing 2, which is made of, for example, synthetic resin and accommodates a power supply circuit, such as a power supply circuit for a welding machine (not shown). External air is introduced into the housing 2 in order to cool components of the power circuit that generate a large amount of heat. The introduced air flows through the inside of the casing 2 and is discharged. To this end, a plurality of air inlet openings 4a are formed on the front panel 2a of the housing 2, and a plurality of air discharge ports 4b are formed on the rear panel 2b, which faces the front panel 2a and is in between. has an interval. To aid in the intake and exhaust of air, a blower 6 is provided within the housing 2 near the rear panel 2b. Power supply units for welding may be used in environments where conductive dust and/or corrosive gases are present. Such conductive dust or corrosive gas tends to enter the casing 2 through the air inlet 4a.

A control and display unit 8 is installed on the casing 2, and the control and display unit 8 is used to set various parameters for the operation of the power supply device and display the operation status of the power supply device, so that the operator can know the current operation status . The control and display unit 8 comprises a control panel 10 which closes an opening 14 formed in the bottom of the recess in the upper part of the front panel 2a. The control panel 10 closes the front of the opening 14 . In other words, the outer peripheral portion of the control panel 10 is superimposed on the front surface of the portion of the front panel 2 a around the opening 14 . The opening 14 is, for example, rectangular, and the control panel 10 is also rectangular and slightly larger than the opening 14 . The control panel 10 is formed of a board 10a, which may be formed of synthetic resin, for example, and a display sheet 10b is bonded to the front surface of the board 10a.

A printed circuit board 16 , for example a printed circuit board for a control panel, is provided within the housing 2 on the inner surface of the board 10 a. The control panel printed circuit board 16 has a rectangular shape and is in contact with the board 10a. A plurality of conductors are printed on the circuit board 16, and a small interval, for example, an interval of less than 5 mm is provided between adjacent conductors.

Also, a plurality of components are mounted on the printed circuit board 16 for the control panel. Components on the printed circuit board 16 include control means 18 such as rotary encoders and switches for setting the operating conditions of the power supply unit. A display device 20 is also mounted on the printed circuit board 16 for displaying the operating status of the device. At least one control device 18 has a controller 18 a that allows an operator to operate the control device 18 from outside the housing 2 . The controller 18a extends outward into the recess 12 through openings (not shown) formed in the plate 10a and the display sheet 10b. The display device 20 has a display unit 20a for displaying the operating state of the power supply device. The display portion 20a extends outward into the recess 12 through openings (not shown) in the plate 10a and the display sheet 10b.

The control panel printed circuit board 16 is enclosed within a container 22 . As shown in FIG. 2 , the container 22 has a wall unit 24 in the shape of a hollow, short rectangular prism extending substantially perpendicularly from the inner surface of the plate 10 a into the housing 2 . The wall unit 24 is formed of synthetic resin and is integrally formed with the panel 10a. The wall unit 24 has longer side walls 24a and 24b parallel to each other, and shorter side walls 24c and 24d which are parallel to each other and perpendicular to the longer side walls 24a and 24b. extend. The longer and shorter side walls 24 a - 24 d are disposed near the periphery of the control panel printed circuit board 16 . The wall unit 24 has an opening at its innermost end.

The opening of the wall unit 24 is closed by a cover. In the illustrated embodiment, another printed circuit board 26 serves as the cover. A part of the power supply circuit is arranged on the printed circuit board 26 . The shape of the printed circuit board 26 is substantially the same as that of the rear opening in the wall unit 24 . Thus, the container 22 is formed by the wall unit 24 and the printed circuit board 26 .

The controller printed circuit board 16 is fixed to the board 10a by means of fixing members 28a and 28b formed on the inner surfaces of the longer side walls 24a and 24b. The fixing members 28a and 28b are integrally formed with the wall unit 24 and are located at midpoints of the longer side walls 24a and 24b, respectively. Fixing members 28a and 28b extend across portions of the inner or rear surface of printed circuit board 16 to press circuit board 16 against board 10a.

At positions on the opposite sides of the respective fixing members 28a and 28b in the walls 24a and 24b of the longer sides, slits 30a and 30b are formed to form tongue-like pieces 32a and 32b on which the fixing members 28a and 28b are respectively formed. Sheets 32a and 32b. In order to install the control panel printed circuit board 16, the circuit board 16 is first placed in the wall unit 24 through the opening at the innermost end of the wall unit 24, and the tongues 32a and 32b are outwardly shown by the arrows in FIG. Bending, so that the fixing members 28a and 28b are also displaced outward. Holding the tongues 32a and 32b in this position moves the printed circuit board 16 over the thus displaced securing members 28a and 28b onto the inner surface of the board 10a. Then, the tongue pieces 32a and 32b are released, so that the fixing members 28a and 28b return to their initial positions shown in FIG. The circuit board 16 is pressed onto the plate 10a.

The printed circuit board 26 is secured to the wall unit 24 with screws (not shown). To this end, ribs 34 are formed at the four inner corners of the wall unit 24 . The rib 34 extends between the rear surface of the plate 10 a and the rear end opening of the wall unit 24 across the entire width of the wall unit 24 . Screw holes are formed on the rear end faces of the respective ribs 34, and screws (not shown) are screwed therein through screw holes 38 formed on the four corners of the printed circuit board 26, thereby installing the printed circuit board 26 to close the wall unit. 24 openings.

With the above arrangement, the printed circuit board 16 for the control panel is placed in the container 22 formed by the wall unit 24 and the printed circuit board 26 . Thus, if the air introduced into the housing 2 through the inlet opening 4a contains conductive dust and/or corrosive gas, the printed circuit board 16 is shielded from contact with such dust and/or gas. The intervals between adjacent printed conductors on the printed circuit board 16 are small, so that if conductive dust adheres to the printed circuit board 16, the insulation between adjacent conductors deteriorates. However, with the above configuration, such insulation deterioration can be suppressed. At the same time, since the control device 18 and the display device 20 are not directly in contact with any corrosive gas that may exist in the cooling gas, they are hardly corroded.

Since the wall unit 24 of the container 22 is integrally formed with the board 10a which is a part of the control panel 10, and the printed circuit board 26 which is a part of the power supply circuit is also used as a cover for closing the rear opening of the wall unit, it can be easily The power supply unit according to the present invention is easily manufactured. Furthermore, the fixing members 28a and 28b for fixing the printed circuit board 16 in the container 22 are integrally formed with the wall unit 24 without using any screws to fix the printed circuit board 16 .

Parts of a power supply unit according to a second embodiment of the present invention are shown in FIG. 3 . The power supply unit according to the second embodiment differs from the power supply unit according to the first embodiment in the way it fixes the printed circuit board 26 . Since the rest of the power supply devices shown in FIGS. 1 and 2 are the same, the same reference numerals are used for the same or similar parts and components, and no further description will be given for them. On the rear surface of the board 10a, spacers 40 are formed integrally with the board 10a at spaced positions. The spacer 40 extends through the control panel printed circuit board 16 to the rear opening of the wall unit 24 . A threaded hole 42 is formed in the rear end surface of the spacer 40, and a screw (not shown) is screwed into the threaded hole 42 through the printed circuit board 26, so that the printed circuit board 26 is fixed to the wall unit 24, and the wall unit 24 The rear opening is closed.

Parts of a power supply unit according to a third embodiment are shown in FIG. 4 . The difference between the power supply unit shown in FIG. 4 and the power supply unit shown in FIGS. 1 and 2 lies in the fixing method of the printed circuit board 26 . Since the rest of the power supply devices shown in FIGS. 1 and 2 are the same, the same reference numerals are used for the same or similar parts and components, and their detailed description will not be repeated. The printed circuit board 26 according to the present embodiment is electrically connected to the printed circuit board 16 for the control panel. To this end, connector 44 is mounted to printed circuit board 16 and connector 46 is mounted to printed circuit board 26 . The lengths of the connectors 44 and 46 are such that when they are connected together, the printed circuit board 26 can be located at the rear opening of the wall unit 24, thereby closing the rear opening.

In the above-described embodiment, the printed circuit board 26 is used as a cover that closes the rear opening of the wall unit 24, but any suitable member may be used instead. For example, a board for mounting components of a power supply device may be used. Also, in the embodiment described above, the shape of the wall unit 24 is a hollow short rectangular prism so as to conform to the rectangular shape of the printed circuit board 16, however, if the shape of the printed circuit board 16 is different, for example, a circle When shaped, the wall unit may have a cylindrical shape. The fixing members 28a and 28b may be formed not on the longer side walls 24a and 24b but on the shorter side walls 24c and 24d.

Claims (3)

1. supply unit comprises:

Housing, this housing has the inside that air can flow and pass;

Panel, the opening that this panel will be formed on the described housing is closed;

First printed circuit board (PCB), this first printed circuit board (PCB) is arranged on after the described panel in described housing; And

A plurality of parts that are installed on described first printed circuit board (PCB) comprise the control device that can operate on the front surface of described panel, and the display device that visual display is provided on the front surface of described panel;

Described first printed circuit board (PCB) is encapsulated in the airtight container of being located in the described housing;

It is characterized in that,

Described container comprises: wall unit, this wall unit extend to the inside of described housing from the rear surface of described panel, and end has rear aperture within it; And the lid of closing described rear aperture, and

Described lid is second printed circuit board (PCB) that separates with described first printed circuit board (PCB).

2. supply unit as claimed in claim 1 is characterized in that, the distance between the adjacent printed conductor on described first printed circuit board (PCB) is very little.

3. supply unit as claimed in claim 1 is characterized in that, described first printed circuit board (PCB) is positioned at the position near the rear surface of described panel, and the fixed component that is used for fixing described first printed circuit board (PCB) is arranged on the inner surface of described wall unit.

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