Control device

It is possible to provide a small-size and light-weight control device having a structure which prevents detaching of a board even when an external shock is applied without using a screwed connection. The control device is formed by a case (1) including at least one board (2, 3), a radiator (5), and a protection cover (4). The case (1) includes at least one latch portion (7, 8) in an upper part or a lower part of a board support frame (16).

TECHNICAL FIELD

The present invention relates to a control device for operating an industrial appliance.

BACKGROUND ART

Two types of control devices have been proposed. In a first example, components are fixed with screws (see, for example, Patent Document 1). In a second example, components are mounted from one direction without using screws (see, for example, Patent Document 2).

Referring toFIG. 11, the first existing example is described. As shown inFIG. 11, a control device is constructed by placing a printed circuit board102on a base103, screwing a screw119into a through hole113in the printed circuit board102and a screw hole106in a board mounting boss107so as to fasten the printed circuit board102to the base103, joining a fitting protrusion in an inner cover mounting boss109of the base103to a fitting recess in a boss116on an inner cover104, pinching the printed circuit board102with the inner cover104, fastening the inner cover104with screws120, and covering the entire base103with a cover105.

Referring toFIGS. 12 and 13, the second existing example is described. As shown inFIG. 12, an existing control device is assembled as follows. First, an LCD case210is fixed to a back surface or another part of a printed circuit board202with connecting pieces211cby soldering or the like. Next, as indicated by arrow A inFIG. 13, a side plate213of an LCD cover212is hooked to bent portions211bof a side plate211of the LCD case210, an LCD cover212is rotated around the hooked portion as indicated by arrow B in the figure, and notches213ain another side plate213of the LCD cover212are engaged with other bent portions211a. By moving the LCD cover212in this state, the bent portions211aand the notches213aare engaged with each other, and the LCD case210is engaged with the LCD cover212, whereby assembly is completed.Patent Document 1: Japanese Unexamined Patent Application Publication No. 2001-244648 (p. 3, FIG. 1)Patent Document 2: Japanese Unexamined Patent Application Publication No. 63-000198 (p. 2, FIGS. 1 and 2)

DISCLOSURE OF INVENTION

Problems to be Solved by the Invention

Control devices are broadly used in the fields of robots, machine tools, automobiles, and the like. High reliability and ease of maintenance are required for a control device, while reduction in size and weight is also desired. Thus, by changing the mounting structure of a control device from a two-dimensional structure to a three-dimensional structure, the space for disposing the control device is efficiently used. However, in the mounting structure of a board, electronic components are densely mounted on the board, the areas to which stacked boards are attached are limited, and it has been desired that a control device be configured such that the boards are not separated even when an external shock is applied.

However, because an existing control device is configured such that stacked boards are fastened with screws, it is necessary to secure a space and an insulation distance for fastening the screws, thereby causing a problem in that reduction in size is hindered. Moreover, there is a problem with fastening using screws in that the screws may be loosened by repeated vibrations or shocks and the boards may fall off. Furthermore, there is a problem in that workability is reduced because it is necessary to remove the screws in order to carry out maintenance of the boards.

In addition, in the case of a top mounting method in an existing control device, there is a problem in that the number of parts increases because parts are used among the components. When the number of parts increases, reduction in size and weight becomes unfeasible, which causes a problem in that the control device has to be disposed in a larger space.

The present invention, which has been achieved to overcome the problems, aims to provide a control device having a structure with which the number of parts is reduced, reduction in the size and weight of the control device is realized, and boards are prevented from falling off when an external shock is applied without using a screw connection.

Means for Solving the Problems

In order to solve the above-described problems, the present invention is configured as follows.

In the invention according to a first aspect, a control device comprises a case, the case including at least one board and a radiator, wherein the case includes at least one latch portion in an upper part or a lower part of a board support frame.

In the invention according to a second aspect, the case includes pillars disposed in four corners and the board support frame connecting the pillars.

In the invention according to a third aspect, the case includes board support frames, a pair of opposing board support frames including latch portions for fixing a first board, and another pair of opposing board support frames including latch portions for supporting a second board.

In the invention according to a fourth aspect, the first board is engaged with the latch portions included in the upper parts of the board support frames and the second board is engaged with the latch portions included in the lower parts of the board support frames.

In the invention according to a fifth aspect, the case includes board support frames, a pair of opposing board support frames including latch portions for fixing a first board in upper parts thereof and elastic holes for supporting a second board in lower parts thereof.

In the invention according to a sixth aspect, at least one guide notch portion for positioning the board with respect to the case is formed in an outer peripheral surface of the board.

In the invention according to a seventh aspect, a latch portion for positioning the radiator with respect to the case is formed in an outer peripheral surface of the radiator.

In the invention according to an eighth aspect, the radiator includes a board including a cooling fan.

In the invention according to a ninth aspect, the control device further comprises a protective cover, wherein at least one recess is formed in an outer peripheral surface of the protective cover and engaged with the latch portion of the case.

In the invention according to a tenth aspect, a control device comprises a case including at least one board and a radiator, wherein the case includes at least two latch portions with different heights in an upper part or a lower part of a board support frame.

In the invention according to an eleventh aspect, at least one pillar is included on a side of the latch portion.

In the invention according to a twelfth aspect, the case includes board support frames, a pair of opposing board support frames including latch portions for fixing at least one of the boards, and another pair of opposing board support frames including latch portions for fixing the board stacked on the at least one of the boards.

In the inventions according to a thirteenth aspect and a fourteenth aspect, the board disposed on the top includes a rib being in contact with a pillar included in the case.

In the inventions according to a fifteenth aspect and a sixteenth aspect, the latch portion engaged with an elastic hole included in the case also serves as a pillar for supporting the board.

Advantages

With the inventions according to the first to sixteenth aspects, because the boards are fixed without using fastening members such as screws, the number of parts can be reduced and the boards are prevented from falling off even when an external shock is applied. Moreover, because the boards are configured to be supported with the latch portions and the elastic holes, assembling and disassembling can be carried out easily, whereby workability in maintenance is improved. Moreover, because the boards can be assembled and removed from above or below the case, workability is improved without increasing the number of parts. Furthermore, because the plurality of boards can be supported by providing the plurality of latch portions of different heights, expandability is high and space can be efficiently used.

In particular, with the inventions according to the eleventh aspect and the thirteenth to sixteenth aspects, the boards are prevented from falling off with external shocks or vibrations, because the pillars and the ribs for fixing the boards are formed so as to hold the boards more securely.

REFERENCE NUMERALS

BEST MODES FOR CARRYING OUT THE INVENTION

First Embodiment

FIG. 1is an exploded view showing a structure of a control device for carrying out a method of the present invention. The figure shows a case1, a first printed circuit board2, a second printed circuit board3, a protective cover4, and a radiator5.

The present invention is different from Patent Document 1 and Patent Document 2 in that the case includes latch portions for fixing the boards to be stacked, the latch portions being disposed in an upper part or a lower part of board support frames of the case.

The case1includes pillar/board positioning portions15in the four corners thereof, each of the pillar/board positioning portions15being connected with board support frames16by adhesion or the like. Alternatively, the pillar/board positioning portions15and the board support frames16are integrally formed. Elastic holes13are formed in lower parts of a pair of board support frames16, and third latch portions11are formed in upper parts of the pair of board support frames16. First latch portions7and second latch portions8are formed in upper parts and lower parts of another pair of board support frames16.

Next, the first printed circuit board2is described. Guide notch portions9are formed in an outer peripheral surface of the first printed circuit board2so that the first printed circuit board2is positioned with respect to the case1.

The second printed circuit board3is described. Guide notch portions10are formed in an outer peripheral surface of the second printed circuit board3so that the second printed circuit board3is positioned with respect to the case1.

The radiator5is described. Latch portions14are formed on a pair of sides of an outer peripheral surface of the radiator5so as to be engaged with the elastic holes13of the case1.

Next, referring toFIGS. 1,2, and3, an assembly process of the control device is described. First, the second printed circuit board3is inserted into the case1such that the guide notch portions10formed in four positions in the outer peripheral surface are positioned along the second latch portions8formed in the case1, and the second printed circuit board3is fixed with the second latch portions8of the case1.

Next, the first printed circuit board2is inserted into the case1such that the guide notch portions9formed in four positions in the outer peripheral surface are positioned along the first latch portions7formed in the case1, and the first printed circuit board2is fixed with the first latch portions7of the case1.

Next, the radiator5is fixed by engaging the latch portions14formed on the outer peripheral surface with the elastic holes13of the case1.

Next, regarding the protective cover4, recesses12formed in its outer peripheral surface are fixed with the third latch portions of the case1.

Second Embodiment

Next, referring toFIGS. 4 and 5, a second embodiment of the present invention is described. The present invention is different from the first embodiment in that a plurality of latch portions are formed in an upper part and a lower part of the board support frames of the case so that three or more printed circuit boards can be fixed.

Differences from the first embodiment are described. In a case21, first latch portions22and second latch portions23are formed in upper parts and lower parts of a pair of board support frames36. Third latch portions24and fourth latch portions25are formed in upper parts and lower parts of another pair of board support frames36. Moreover, first pillars34and second pillars35are formed adjacent to the third latch portions24and the fourth latch portions25.

Next, referring toFIGS. 4 and 5, an assembly process is described. First, a second printed circuit board27is inserted into the case21such that guide notch portions31formed in four positions in the outer peripheral surface are positioned along the second latch portions23formed in the case21, and the second printed circuit board27is fixed with the second latch portions23of the case21.

Next, a first printed circuit board26is inserted into the case21such that guide notch portions30formed in four positions in the outer peripheral surface are positioned along the first latch portions22formed in the case21, and the first printed circuit board26is fixed with the first latch portions22of the case21.

Next, a fourth printed circuit board29is inserted into the case21such that guide notch portions33formed in four positions in the outer peripheral surface are positioned along the fourth latch portions25formed in the case21, and the fourth printed circuit board29is fixed with the fourth latch portions25of the case21. At this time, the fourth printed circuit board29is fixed while being supported by the second pillar35.

Next, a third printed circuit board28is inserted into the case21such that guide notch portions32formed in four positions in the outer peripheral surface are positioned along the third latch portions24formed in the case21, and the third printed circuit board28is fixed with the third latch portions24of the case21. At this time, the third printed circuit board28is fixed while being supported by the first pillars34.

In the embodiment described here, latch portions of different heights are disposed in pairs on board support frames. However, latch portions of different heights may be disposed on the same board support frame. Needless to say, that latch portions of different heights may be disposed, for example, on a pair of opposing board support frames. The embodiment is described using an example having four printed circuit boards. However, needless to say, four or more printed circuit boards can be stacked by forming latch portions of different heights. Not only printed circuit boards, but also a combination of radiators and protective covers can be stacked.

Third Embodiment

Next, referring toFIG. 6, a third embodiment of the present invention is described. The third embodiment is different from the first embodiment and the second embodiment of the present invention in that elastic holes are formed in a pair of upper parts of an outer peripheral surface of a case so as to fix a cooling fan plate.

As shown inFIG. 6, a cooling fan plate17has latch portions20formed in a pair of sides of an outer peripheral surface thereof, and the cooling fan plate17is disposed such that the latch portions20are fixed to elastic holes13formed in a pair of upper parts of an outer peripheral surface of a case1.

Fourth Embodiment

Next, referring toFIGS. 7 and 8, a fourth embodiment of the present invention is described. The fourth embodiment is different from the first to third embodiments of the present invention in that latch portions of a radiator fixed to elastic holes formed in a pair of lower parts of an outer peripheral surface of a case also serve as pillars for supporting a board positioned above.

FIG. 7shows a sectional view of a control device, andFIG. 8shows an enlarged view of a latch portion. Latch portions8formed in a radiator5are fit into elastic holes13of a case1, and the radiator5is fixed to the case1. At this time, the latch portions8are disposed so that the latch portions8support the bottom surface of the second printed circuit board3and fix the second printed circuit board3.

Although the latch portions are formed in the radiator and fitted into the elastic holes in the case so that the printed circuit board is supported from the bottom, it is not necessary that the latch portions be formed in the radiator. The latch portions may be formed in a component attached to the case, such as a printed circuit board or a protective cover. Moreover, although the radiator including the latch portions is disposed at the lowermost position in the configuration described here, it is not necessary that the latch portions be disposed at the lowermost position. It is evident that a board including the latch portions may be a board in the middle of the stack.

Fifth Embodiment

Next, referring toFIGS. 9 and 10, a fifth embodiment of the present invention is described. The fifth embodiment is different from the first to fourth embodiments of the present invention in that ribs are formed on a cover in contact with the pillar/board positioning portions in the four corners of the case.

FIG. 9shows a perspective view of the control device, andFIG. 10shows an enlarged view of a rib portion. Ribs41are formed on a protective cover4, and a surface of the each rib41is disposed in contact with a corresponding pillar/board positioning portion15in a case1. By doing so, falling off is prevented due to a supporting effect of the ribs41.

Industrial Applicability

The present invention is also applicable to a multi-axis control device, because the number of stacks can be increased by increasing the number of latch portions and pillars on the board support frames.