1363590 九、發明說明 【發明所屬之技術領域】 本發明係一種電源裝置，尤其是有關一種於電源裝 置所使用之印刷電路基板之配置者。 【先前技術】 已知之電源裝置，例如電焊機用電源裝置，將操作 面板裝設於裝置之構體外面。備有此等操作面板之電源 裝置之例有日本國專利公開公報2003-1 369241號者。構 體外面設有操作面板之該電源裝置，在操作面板上有： 各種設定器，可設定電源裝置所輸出之電流、電壓之狀 態；開關，可選擇電源裝置之運轉模式；及顯示燈，可 監視運轉狀態。雖上述公報無記載，但是此等設定器、 開關及顯示燈，均裝設於一片操作面板用印刷電路基板 上。此操作面板用印刷電路基板係屬高密度封裝者。如 此，形成於操作面板用印刷電路基板之印刷導體互相間 之間隔甚小，例如僅未滿〇.5mm等。該高密度封裝之操 作面板用印刷電路基板係固定於上述操作面板背面。而 操作面板形成有多數開口。由此開口，使上述設定器之 操作部、開關之操作部分及顯示燈等露出於表面，方能 自外部操作設定器或開關，並確認顯示燈之顯示內容。 電源裝置因需冷卻構體內部，而吸入外部空氣至構 體內。此時，經高密度封裝之操作面板用印刷電路基板 將暴露於吸入至裝置內之空氣。 電焊用電源裝置，係在有導電性灰塵或腐蝕性氣體 1363590 之環境下使用。此時，此等導電性灰塵或腐蝕性氣體將 進入構體內部，以致操作面板用印刷電路基板受到導電 性灰塵或腐蝕性氣體之影響。尤其是上述操作面板用印 刷電路基板爲高密度封裝者，較一般印刷電路基板易受 影響，如導電性灰塵附著於操作面板用印刷電路基板， 必降低其絶緣性能，或裝設於操作面板用印刷電路基板 之零組件腐蝕性氣體之侵蝕，以致電源裝置發生故障。 【發明內容】 本發明之目的在於防護操作面板用印刷電路基板自 電源裝置周邊之空氣，避免受其影響。 本發明之電源裝置之一種方式爲，具備內部可流通 空氣之構體。爲使空氣在構體內流通，例如在構體之不 同位置設有空氣流入口與空氣排出口。而且，爲促使構 體內之空氣流通，在構體內裝設風扇爲佳。操作面板覆 蓋在形成於構體之開□。操作面板亦可在構體外面覆蓋 開口，或在構體內面覆蓋開口。於上述構體內部，在上 述操作面板背面有操作面板用印刷電路基板。操作面板 用印刷電路基板上裝有多數零組件。此等零組件包含， 可自上述操作面板前面可操作之操作單元，與在上述操 作面板前面可視認之顯示裝置。操作單元將其可操作部 分貫穿面板突出於操作面板前面爲佳。又，顯示裝置之 顯示部分可貫穿面板位於操作面板前面爲佳。操作面板 用印刷電路基板收容於上述構體內之密閉容器內。 於此電源裝置，在構體內流通之空氣既使爲導電性 -6 - 1363590 灰塵或腐蝕性氣體，亦因操作面板用印刷電路基板收容 於容器內而不與導電性灰塵或腐蝕性氣體接觸。因此操 作面板用印刷電路基板之絶緣性能不致降低，又，裝設 於操作面板用印刷電路基板之零組件及印刷導體亦不腐 蝕。 操作面板用印刷電路基板，在其上形成之多數印刷 導體之間隔可縮短。操作面板用印刷電路基板之印刷導 體間隔小時，如附著少許導電性灰塵就容易引起印刷導 體之劣化，但是操作面板用印刷電路基板因收容於容器 內，因此操作面板用印刷電路基板之絶緣性能不致劣化 0 上‘述容器爲，自上述操作面板背面再向上述構體內 部延伸而在前端部有開口之牆壁’與能關閉此牆壁開口 之蓋子。牆壁與上述操作面板能一體形成爲佳。於如此 構成之電源裝置，因在操作面板形成上述牆壁’牆壁之 操作面板邊端部係由操作面板所關閉’無需在操作面板 另裝設關閉此端部之構件，而可簡化此電源裝置之構造 〇 上述蓋子，可不同於操作面板用印刷電路基板’另 作爲另一印刷電路基板。如此構成則無需設専用蓋子’ 而可簡化電源裝置之構造。 再者，操作面板用印刷電路基板可接近於上述操作 面板之背面配置。此時，固定上述操作面板用印刷電路 基板之繫止具設於上述牆壁之內面。繫止具應比操作面 1363590 板用印刷電路基板邊緣向操作面板用印刷電路基板內側 延伸爲佳。如此構成，則爲固定操作面板用印刷電路基 板無需使用螺栓或粘著劑，而簡化電源裝置之製造。 【實施方式】 圖1及圖2爲本發明之一實施方式之電焊機用電源裝 置。如圖1所示此電源裝置具備構體2。此構體2例如爲 塑膠製，在其內面有電路，例如電焊機用電路（不圖示） 。爲冷卻在此電路所用零組件中發熱大之零組件，構體 內需吸入外部空氣，使其通過構體2內後排出至外部。 爲此，構體2之正面面板2a形成多數吸氣口 4a，與正面 面板相對之背面面板2b形成多數排氣口 4b。又，爲促使 空氣之導入與排出，在構體2內，配置送風機6靠近背面 面板2b。電焊機用電源裝置，多因在導電性灰塵中或腐 蝕性氣體之環境下使用。如是，導電性灰塵或腐蝕性氣 體將有由吸氣口 4a侵入構體內部之慮。 構體2設有操作顯示部8，可設定電源裝置之動作， 及確認電源裝置之運轉狀態。此操作顯示部8具有操作 面板10。操作面板10，在形成於正面面板2a上面之凹部 12深處形成之開口 14，係由正面面板2 a之前面覆蓋。換 言之，操作面板10之外緣部、在開口 14之周圍於正面面 板2a之前面上。開口 14爲例如長方形狀者。操作面板10 係由平板l〇a與貼合於其前面之顯示片l〇b所構成。平板 10a、例如爲塑膠製。 於構體2內部，平板l〇a背面配置印刷電路基板，例 1363590 如操作面板用印刷電路基板1 6。此操作面板用印刷電路 基板16係與平板10a接觸配置之長方形狀者。在此電路 基板1 6a形成之多數印刷導體，其間隔甚接近，例如間 隔未滿5〇1111者。 於操作面板用印刷電路基板16裝設多數零組件。零 組件包含操作單元1 8，例如爲設定此電源裝置之動作狀 態之旋轉編碼器、開關等。又，零組件亦包含顯示電源 裝置之動作狀態之顯示裝置20。操作單元18中至少有一 件爲作業者可從構體2外部操作之操作部分18a，此係貫 穿在平板10與顯示片l〇b所形成之開口（無圖示），突出於 凹部12內。又，顯示裝置20亦有顯示此電源裝置之動作 狀態之顯1示部20，此亦貫穿在平板10與顯示片10b所形 成之開口（無圖示），突出於凹部12內。 .操作面板用印刷電路基板16，其外周圍由容器22覆 蓋。如圖2所示，容器22有牆壁部24。此牆壁部24爲自 平板l〇a之背面向平板10a略成垂直延伸至構體2之深部 之短角筒狀者。此牆壁部24爲塑膠製與平板10a成形爲 一體。牆壁部24具互相平行之長牆壁24a、24b。牆壁部 24亦具互相平行，且與長牆壁成垂直之短牆壁24c、24d 。此等長牆壁24a、24b及短牆壁24c、24d，位於接近操 作面板用印刷電路基板16之外周圍。牆壁部24在其深處 端部有開口。 此開口由蓋子關閉。此蓋子在本實施方式係使用由 上述電路之構成一部分線路之另一印刷電路基板26。此 1363590 印刷電路基板26之形狀與牆壁部24之上述開口略一致。 由牆壁部24與印刷電路基板26 ’形成容器22。 操作面板用印刷電路基板16，係由設在牆壁部24內 面之固定具28a、28b固定於平板10a。固定具28a、28b係 在長牆壁24a、24b內面之中央部’與長牆壁24a、24b形 成爲一體·此等固定具28a、28b超越操作面板用印刷電 路基板16背面外周圍，與操作面板用印刷電路基板16背 面接觸，將操作面板用印刷電路基板16推壓固定在平板 1 Oa ° 爲易於推壓固定，於形成長牆壁24a、24b之固定具 28a、28b之部分兩邊，如圖2所示分別形成切口 30a、 3〇b，形成固定具28a、28b之部分作爲片狀部32a、· 32b 。在裝設操作面板用印刷電路基板16時，從牆壁部24之 開口將操作面板用印刷電路基板16放入牆壁部24內，片 狀部32a、3 2b將如圖2箭頭所示方向繞住其外側，固定 具2 8a、2 8b亦朝外。如此狀態使操作面板用印刷電路基 板16跨越朝外之固定具28a、28b，在平板10a之背面放 入操作面板用印刷電路基板16 ·然後，退回片狀部32a 、3 2b，則如圖1所示固定具28a、2 8b還元至如圖1所示 之原來之位置，與操作面板用印刷電路基板16之背面接 觸，將操作面板用印刷電路基板16推壓在平板10a。 印刷電路基板26由無圖示之螺栓固定於牆壁部24。 爲此，在牆壁24之四角落內面，分別形成棱34。此等棱 34係自平板l〇a背面延伸至牆壁24之後部開口。在其等 -10- 1363590 開口之端部分別形成螺栓孔36。此等螺栓孔36，與揷入 印刷電路基板26之四角落所形成之螺栓通孔38之螺栓（無 圖示）可旋緊，將印刷電路基板26固定於牆壁部24之開口 ，將開口關閉。 於如此構成之電源裝置，操作面板用印刷電路基板 1 6係收容於由牆壁部24與印刷電路基板26所構成之容器 22內。因此，既使吸氣口 4a吸入之空氣含有導電性灰塵 或腐蝕性氣體，也與操作面板用印刷電路基板16隔開， 導電性灰塵或腐蝕性氣體不直接與操作面板用印刷電路 基板1 6接觸·因形成於操作面板用印刷電路基板1 6之印 刷導體間之間隔狹窄，如附着導電性灰塵時，操作面板 用印刷'電路基板1 6之印刷導體之絶緣性容易劣化。但是 於本電源裝置，則操作面板用印刷電路基板1 6之絶緣性 不易劣化。而且，操作單元18及顯示裝置20亦不直接與 腐蝕性氣體接觸，因此操作單元18及顯示裝置20亦不致 腐蝕。 而且，容器22之牆壁部24，係與構成操作面板之一 部分之平板l〇a形成爲一體、又蓋子係使用作爲一部分 電源電路之印刷電路基板26而製造容易。又，牆壁部24 係與固定操作面板用印刷電路基板16用固定具28a、28b 形成爲一體，而固定操作面板用印刷電路基板16無需使 用螺栓。 圖3爲本發明第2實施方式之電源裝置。於此電源裝 置，其印刷電路基板26之固定與圖1之電源裝置有所不 -11 - 1363590 同。其他部分均與圖1之電源裝置相同。在同一部分用 同一符號而省略其説明。於此電源裝置，在離開平板 l〇a背面位置有多處形成墊片與平板l〇a形成爲一體》此 等墊片l〇a貫穿操作面板用印刷電路基板16延伸至牆壁 部24之後部開口。然後在此後部開口端部形成螺栓孔42 ，與貫穿印刷電路基板26之螺栓可旋緊，在印刷電路基 板26關閉牆壁部24之開口之狀態下，固定於牆壁部24。 圖4爲本發明之電源裝置第3實施方式。此電源裝置 之印刷電路基板26之固定與圖1之電源裝置不同。其他 部分則與圖1之電源裝置相同。同一部分用同一符號而 省略其説明。於本電源裝置，印刷電路基板26係與操作 面板用印刷電路基板16電接通。爲此連接，在操作面板 用印刷電路基板16裝設連結器44，而印刷電路基板26亦 有連結器46。連結此連結器44、46，可使印刷電路基板 26位於牆壁部24之後部開口。爲此，要在連接連結器44 、46之狀態下配合印刷電路基板26能位於牆壁部24之後 部開口，可選擇適當長度之連結器44、46。 於上述各實施方式，係使用印刷電路基板26，但是 只要能關閉牆壁部24者均可使用，例如裝設零組件之板 亦可使用。於上述實施方式，操作面板用印刷電路基板 16爲長方形狀，因此牆壁部24亦使用角筒狀者，但是， 操作面板用印刷電路基板1 6如爲其他形狀，例如爲圓形 ，則牆壁部亦可爲圓筒狀。又，固定具28a、28b設於長 牆壁24a、24b，亦可代替設於短牆壁24 c、24d，也可 -12- 1363590 分別設於長牆壁24a、24b與短牆壁24c、24d。 【圖式簡單說明】 圖1 本發明之一種實施方式之電源裝置之部分省 略豎向剖側面圖； 圖2 圖1之電源裝置之面板部分之組裝圖； 圖3 本發明之另一實施方式之電源裝置之部分省 略豎向剖側面圖； 圖4 本發明之再一實施方式之電源裝置之部分省 略豎向剖側面圖。 【主要元件符號說明】 2 構體 2b' ^背面面板 4b 排氣口 10 操作面板 10b顯示片 14 開口 18 操作單元 22 容器 24a、24b長牆壁 26 印刷電路基板 36 螺栓孔 2a 正面面板 4a 吸氣口 8 顯不部 10a平板 12 凹部 16 操作面板用印刷電路基板 20 顯示裝置 24 牆壁部 24c、24d 短牆壁 28a、28b固定具 44、46 連結器1363590 IX. Description of the Invention The present invention relates to a power supply device, and more particularly to a configurator of a printed circuit board used in a power supply device. [Prior Art] A known power supply device, such as a power supply device for an electric welder, mounts an operation panel outside the structure of the device. An example of a power supply unit having such an operation panel is Japanese Patent Laid-Open Publication No. 2003-1 369241. The power supply device of the operation panel is arranged outside the structure, and the operation panel has: various setting devices, which can set the current and voltage state outputted by the power supply device; the switch can select the operation mode of the power supply device; and the display lamp can be Monitor the operating status. Although not described in the above publication, these setters, switches, and display lamps are mounted on a single printed circuit board for an operation panel. The printed circuit board for this operation panel is a high-density package. As a result, the distance between the printed conductors formed on the printed circuit board for an operation panel is extremely small, for example, only less than .5 mm. The printed circuit board for an operation panel of the high-density package is fixed to the back surface of the operation panel. The operation panel is formed with a plurality of openings. With this opening, the operation portion of the setter, the operation portion of the switch, the display lamp, and the like are exposed on the surface, and the setter or switch can be operated from the outside, and the display content of the display lamp can be confirmed. The power supply unit draws in the outside of the structure and draws in outside air into the body. At this time, the printed circuit board for the operation panel which is packaged in high density is exposed to the air sucked into the apparatus. The power supply unit for electric welding is used in the environment of conductive dust or corrosive gas 1363590. At this time, such conductive dust or corrosive gas will enter the inside of the structure, so that the printed circuit board for the operation panel is affected by conductive dust or corrosive gas. In particular, the printed circuit board for the operation panel is a high-density package, which is more susceptible to the general printed circuit board. For example, conductive dust adheres to the printed circuit board for the operation panel, and the insulation performance is lowered or installed on the operation panel. The corrosion of the corrosive gas of the components of the printed circuit board causes the power supply device to malfunction. SUMMARY OF THE INVENTION An object of the present invention is to protect a printed circuit board for an operation panel from the air surrounding the power supply device from being affected. One mode of the power supply device of the present invention is to have a structure in which air can flow inside. In order to allow air to circulate in the body, for example, an air inflow port and an air discharge port are provided at different positions of the body. Moreover, in order to promote the circulation of air in the body, it is preferable to install a fan in the body. The operation panel is covered by the opening formed in the structure. The operation panel may also cover the opening outside the body or cover the opening in the body. Inside the above-described structure, a printed circuit board for an operation panel is provided on the back surface of the operation panel. Operation panel Most components are mounted on the printed circuit board. These components include an operating unit operable from the front of the operating panel and a display device visible in front of the operating panel. It is preferred that the operating unit protrudes from the front of the operation panel through its operable portion. Further, it is preferable that the display portion of the display device is located in front of the operation panel through the panel. Operation panel The printed circuit board is housed in a sealed container in the above-described structure. In this power supply device, the air flowing through the structure is electrically conductive -6 - 1363590 dust or corrosive gas, and the printed circuit board for operation panel is housed in the container without coming into contact with conductive dust or corrosive gas. Therefore, the insulating performance of the printed circuit board for the operation panel is not lowered, and the components and printed conductors mounted on the printed circuit board for the operation panel are not corroded. In the printed circuit board for an operation panel, the interval between a plurality of printed conductors formed thereon can be shortened. When the printed conductor of the printed circuit board is separated by a small amount of conductive dust, the printed conductor is easily deteriorated. However, since the printed circuit board for the operation panel is housed in the container, the insulating property of the printed circuit board for the operation panel is not improved. Deterioration 0 The above-mentioned container is a wall that extends from the back surface of the operation panel to the inside of the above-mentioned structure and has an opening at the front end portion and a cover that can close the wall opening. It is preferable that the wall and the above operation panel can be integrally formed. In the power supply device thus constructed, since the operation panel is formed at the edge of the operation panel on the operation panel, the end portion of the operation panel is closed by the operation panel, and the power supply device can be simplified without separately installing a member for closing the end portion on the operation panel. The cover described above may be different from the printed circuit board for operation panel as another printed circuit board. According to this configuration, it is not necessary to provide a cover ‘ to simplify the structure of the power supply unit. Further, the printed circuit board for the operation panel can be disposed close to the back surface of the operation panel. At this time, the stopper for fixing the printed circuit board for the operation panel is provided on the inner surface of the wall. It is preferable that the end of the printed circuit board of the board is extended to the inside of the printed circuit board for the operation panel. According to this configuration, the printed circuit board for fixing the operation panel does not require the use of bolts or adhesives, and the manufacture of the power supply device is simplified. [Embodiment] Figs. 1 and 2 show a power supply device for an electric welding machine according to an embodiment of the present invention. This power supply device is provided with a structure 2 as shown in FIG. The structure 2 is made of, for example, plastic, and has an electric circuit on its inner surface, for example, a circuit for an electric welder (not shown). In order to cool the components that are hot in the components used in this circuit, the outside air is taken in the structure and passed through the inside of the structure 2 and then discharged to the outside. For this reason, the front panel 2a of the structure 2 forms a plurality of intake ports 4a, and the rear panel 2b opposed to the front panel forms a plurality of exhaust ports 4b. Further, in order to promote the introduction and discharge of air, the blower 6 is disposed in the structure 2 close to the back panel 2b. Power supply units for electric welding machines are often used in the presence of conductive dust or corrosive gases. If so, conductive dust or corrosive gas will be invaded by the suction port 4a into the interior of the structure. The structure 2 is provided with an operation display unit 8, which can set the operation of the power supply device and confirm the operation state of the power supply device. This operation display portion 8 has an operation panel 10. The operation panel 10, which is formed in the depth of the recess 12 formed on the upper surface of the front panel 2a, is covered by the front surface of the front panel 2a. In other words, the outer edge portion of the operation panel 10 is on the front surface of the front panel 2a around the opening 14. The opening 14 is, for example, a rectangular shape. The operation panel 10 is composed of a flat panel 10a and a display panel 10b attached to the front side thereof. The flat plate 10a is made of, for example, plastic. Inside the structure 2, a printed circuit board is disposed on the back surface of the flat plate 10a, and an example 1363590 is a printed circuit board 16 for an operation panel. The operation panel printed circuit board 16 is formed in a rectangular shape in contact with the flat plate 10a. Most of the printed conductors formed on this circuit substrate 16a are closely spaced, for example, if the interval is less than 5 〇 1111. A plurality of components are mounted on the printed circuit board 16 for the operation panel. The component includes an operation unit 18, for example, a rotary encoder, a switch, or the like that sets an operation state of the power supply device. Further, the components also include a display device 20 that displays the operational state of the power supply unit. At least one of the operating units 18 is an operating portion 18a that the operator can operate from outside the structure 2, which is penetrated through an opening (not shown) formed by the flat plate 10 and the display sheet 10b, and protrudes into the recess 12. Further, the display device 20 also has a display portion 20 for displaying the operation state of the power supply device, and also extends through the opening (not shown) formed by the flat plate 10 and the display sheet 10b, and protrudes into the concave portion 12. The printed circuit board 16 for an operation panel is covered by a container 22 at its outer periphery. As shown in FIG. 2, the container 22 has a wall portion 24. The wall portion 24 is a short-angled cylinder extending from the back surface of the flat plate 10a to the flat plate 10a so as to extend vertically to the deep portion of the body 2. This wall portion 24 is formed of a plastic material and is integrally formed with the flat plate 10a. The wall portion 24 has long walls 24a, 24b parallel to each other. The wall portion 24 also has short walls 24c, 24d which are parallel to each other and which are perpendicular to the long wall. The equal-length walls 24a, 24b and the short walls 24c, 24d are located close to the periphery of the printed circuit board 16 for operation panels. The wall portion 24 has an opening at its deep end. This opening is closed by the cover. In the present embodiment, the cover uses another printed circuit board 26 which is formed by a part of the above-described circuit. This 1363590 printed circuit board 26 has a shape that slightly coincides with the above-described opening of the wall portion 24. The container 22 is formed by the wall portion 24 and the printed circuit board 26'. The printed circuit board 16 for operation panel is fixed to the flat plate 10a by fixing members 28a and 28b provided on the inner surface of the wall portion 24. The fixing members 28a and 28b are integrally formed with the long walls 24a and 24b at the central portion of the inner surfaces of the long walls 24a and 24b. These fixing members 28a and 28b extend beyond the outer periphery of the back surface of the operation panel printed circuit board 16 and the operation panel. The printed circuit board 16 is pressed against the back surface of the printed circuit board 16, and the printed circuit board 16 for the operation panel is pressed and fixed to the flat plate 1 Oa ° for easy pressing and fixing, and is formed on both sides of the fixing members 28a and 28b of the long walls 24a and 24b, as shown in FIG. The slits 30a and 3b are formed as shown, and the portions of the fixtures 28a and 28b are formed as the sheet portions 32a and 32b. When the printed circuit board 16 for operation panel is mounted, the operation panel printed circuit board 16 is placed in the wall portion 24 from the opening of the wall portion 24, and the sheet portions 32a and 32b are wound in the direction indicated by the arrow in FIG. On the outside, the fixtures 28 8a and 28b are also facing outward. In this state, the operation panel printed circuit board 16 is placed over the outwardly facing fixtures 28a and 28b, and the operation panel printed circuit board 16 is placed on the back surface of the flat panel 10a. Then, the sheet portions 32a and 32b are retracted, as shown in FIG. The fixing tools 28a and 28b are returned to the original position as shown in FIG. 1, and are in contact with the back surface of the operation panel printed circuit board 16, and the operation panel printed circuit board 16 is pressed against the flat plate 10a. The printed circuit board 26 is fixed to the wall portion 24 by bolts (not shown). To this end, ribs 34 are formed on the inner faces of the four corners of the wall 24, respectively. These ribs 34 extend from the back of the panel l〇a to the rear of the wall 24. Bolt holes 36 are formed at the ends of the openings of the -10- 1363590, respectively. These bolt holes 36 are screwed with bolts (not shown) that are inserted into the bolt through holes 38 formed at the four corners of the printed circuit board 26, and the printed circuit board 26 is fixed to the opening of the wall portion 24, and the opening is closed. . In the power supply device configured as described above, the printed circuit board for operation panel 16 is housed in the container 22 composed of the wall portion 24 and the printed circuit board 26. Therefore, even if the air taken in by the intake port 4a contains conductive dust or corrosive gas, it is also separated from the printed circuit board 16 for the operation panel, and the conductive dust or corrosive gas is not directly connected to the printed circuit board for the operation panel. The contact between the printed conductors formed on the printed circuit board 16 for the operation panel is narrow, and when the conductive dust is adhered, the insulation of the printed conductor of the printed circuit board for the operation panel is easily deteriorated. However, in the power supply device, the insulation of the printed circuit board 16 for the operation panel is not easily deteriorated. Further, since the operation unit 18 and the display device 20 are not directly in contact with the corrosive gas, the operation unit 18 and the display device 20 are not corroded. Further, the wall portion 24 of the container 22 is integrally formed with the flat plate 10a constituting one of the operation panels, and the cover is easily manufactured by using the printed circuit board 26 as a part of the power supply circuit. Further, the wall portion 24 is integrally formed with the fixtures 28a and 28b for the printed circuit board 16 for fixing the operation panel, and the printed circuit board 16 for the operation panel is fixed without using a bolt. Fig. 3 shows a power supply device according to a second embodiment of the present invention. In this power supply device, the fixing of the printed circuit board 26 is the same as that of the power supply unit of Fig. 1. The other parts are the same as the power supply unit of Fig. 1. The same reference numerals are used in the same parts, and the description thereof is omitted. In the power supply device, a plurality of spacers are formed at a position away from the rear surface of the flat plate 10a, and the flat plate 10a is formed integrally. The spacers 10a extend through the operation panel printed circuit board 16 to the rear of the wall portion 24. Opening. Then, a bolt hole 42 is formed in the rear opening end portion, and the bolt penetrating through the printed circuit board 26 can be screwed, and the printed circuit board 26 is fixed to the wall portion 24 with the opening of the wall portion 24 closed. Fig. 4 shows a third embodiment of the power supply device of the present invention. The fixing of the printed circuit board 26 of this power supply unit is different from that of the power supply unit of Fig. 1. The other parts are the same as the power supply unit of Figure 1. The same portions are denoted by the same reference numerals and the description thereof will be omitted. In the present power supply device, the printed circuit board 26 is electrically connected to the printed circuit board 16 for the operation panel. For this connection, the connector 44 is mounted on the printed circuit board 16 of the operation panel, and the printed circuit board 26 is also provided with a connector 46. By connecting the connectors 44 and 46, the printed circuit board 26 can be opened at the rear of the wall portion 24. For this reason, the printed circuit board 26 can be placed in the rear of the wall portion 24 in the state in which the connectors 44 and 46 are connected, and the connectors 44 and 46 of an appropriate length can be selected. In the above embodiments, the printed circuit board 26 is used. However, any of the panels 24 can be used. For example, a board on which components are mounted can be used. In the above-described embodiment, the printed circuit board 16 for the operation panel has a rectangular shape. Therefore, the wall portion 24 also has a rectangular tube shape. However, the operation panel printed circuit board 16 has other shapes, for example, a circular shape, and the wall portion is used. It can also be cylindrical. Further, the fixtures 28a and 28b are provided on the long walls 24a and 24b, and may be provided on the short walls 24c and 24d instead of the short walls 24c and 24d, and may be provided on the long walls 24a and 24b and the short walls 24c and 24d, respectively. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially omitted side elevational view of a power supply unit according to an embodiment of the present invention; FIG. 2 is an assembled view of a panel portion of a power supply unit of FIG. 1; A part of the power supply unit is omitted from the vertical sectional side view. Fig. 4 is a partially omitted side elevational view of the power supply unit according to still another embodiment of the present invention. [Main component symbol description] 2 Structure 2b' ^Back panel 4b Exhaust port 10 Operation panel 10b Display sheet 14 Opening 18 Operating unit 22 Container 24a, 24b Long wall 26 Printed circuit board 36 Bolt hole 2a Front panel 4a Suction port 8 display part 10a flat plate 12 recessed part 16 printed circuit board for operation panel 20 display device 24 wall portion 24c, 24d short wall 28a, 28b fixture 44, 46 connector