JPH09322334A - Control board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the quantity of heat in a dustproof section of a case body and to prevent an electric discharge machine and others disposed adjacently to the case body from being affected thermally. SOLUTION: A ventilation section 92 is formed, with a switching unit 51 fitted, in a unit guide 10 which is provided so to surround an intake port 2B bored in a first side plate 2 and an exhaust port 4A bored in a partition plate 4. A main heat sink 18 to which heating semiconductor elements 52 in a dustproof section 90 are connected is disposed in the ventilation section 92 and cooled forcedly with external air by a cooling fan 57 disposed at the intake port 2B. An exhaust flow formed thereby is deflected by an air guide plate 13, made to flow through a draft section 91 and exhausted from an exhaust port 5A so that it goes away from a machine tool which is disposed adjacently to the first side plate 2. A heat transfer plate 30 for cooling indirectly the inside of the dustproof section 90 is disposed in the draft section 91.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an improvement of a control panel which accommodates a switching unit used in a power supply device of an electric discharge machine and is provided with an electric operation section and is installed adjacent to the electric discharge machine. It is about.

[0002]

2. Description of the Related Art A control panel for accommodating a power supply device such as an electric discharge machine or a laser machining machine has various types such as a switching unit equipped with a heat sink and a cooling fan for cooling a heat-generating semiconductor element. Contains electronic and electrical equipment. Usually, the control panel is constructed in a dustproof manner so that external dust or oil mist does not enter the panel. In addition, a cooling device is provided to remove the heat generated by the switching unit, the electronic device, and the electric device housed in the dustproof compartment to the outside and maintain the temperature in the dustproof compartment within an allowable range. As the cooling device, an air conditioner using a refrigerant or a heat exchanger using a heat pipe or a corrugated heat transfer plate is used. In addition, for electrical operation, it is equipped with an operation unit consisting of a CRT, sheet key switch, and the like. The control panel is installed on the floor adjacent to an electric discharge machine or the like in order to improve operability and electrical performance.

The F mounted on the switching unit
The heat generating semiconductor elements such as ET and IGBT generate a large amount of heat due to the high speed switching operation. For this reason, conventionally, the fin portion of the heat sink to which the heat-generating semiconductor element is attached is exposed to the outside of the dustproof compartment, and the fin portion is forcibly cooled by a cooling fan. This allows
It is possible to reduce heat generation in the dustproof compartment, downsize the cooling device, and reduce the cost required for cooling.

[0004]

In a normal electric discharge machine, in order to obtain a large discharge current by parallel operation,
Requires two or more switching units. When the above switching units are arranged vertically to reduce the installation area of the control panel, the heat sink of the upper switching unit is heated by the heat radiation from the heat sink of the lower switching unit, and May not be maintained below the temperature of. Even if the control panel is installed on the floor adjacent to the electric discharge machine, the switching unit and its output terminals housed in the control panel are not mounted in a position close to the electric discharge machine. However, there is a problem that the power supply cable between the output terminal and the machining electrode of the electric discharge machine is long and the peak output current from the switching unit is attenuated. Furthermore, it is easy to operate electrically from the working position of the machine body, and the CRT
It is desirable that the screen is easy to see and that the exhaust heat does not adversely affect the machine body that is installed on the floor next to it.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to minimize the length of the power supply cable from a plurality of switching units and to make the heat sink of the switching units dustproof of the housing. It is arranged outside the compartment to reduce the amount of heat generated inside the dust compartment, and the cooling device for the interior of the dust compartment can be made small and inexpensive, and even if a plurality of switching units are compactly arranged, Satisfactorily forcibly cooled without affecting the
The purpose of the present invention is to obtain a control panel that can be installed without having a thermal effect on the machine body such as an electric discharge machine that is placed adjacent to it, and that is also highly economical.

[0006]

A control panel according to a first aspect of the present invention is a control panel which is hermetically sealed from a front door in a dustproof manner and which has a casing having first and second side plates. The intake port formed in the one side plate, the exhaust port formed in the back surface of the housing, and the corner portion in the housing that surrounds the intake port and the exhaust port are divided, and the front surface of the housing and the A unit guide with a removable opening on the side of the second side plate, a unit panel that is inserted into the unit guide and divides the corners of the housing into ventilation compartments, and the opening formed in the unit panel is closed. A heat sink disposed in the ventilation compartment, a semiconductor element attached to the base plate of the heat sink, a switching unit including a printed circuit board electrically connected to the semiconductor element, and an intake port. Together are arranged, it is characterized in that it comprises in circulation between the inlet and outlet and a cooling fan for forced convection of the outside air to the heat radiating fins of the heat sink. Therefore, a ventilation section is formed between the unit guides arranged at the corners of the first side plate and the rear plate arranged close to the machine tool and the unit panel of the switching unit inserted into the unit guide. The heat sink placed in the ventilation compartment is forcibly air-cooled by the outside air flowing from the intake port of the first side plate to the exhaust port of the back plate by the cooling fan, and the exhaust heat is horizontally discharged to the outside of the housing. The amount of heat generated in the board is reduced.

In the control panel according to the second aspect of the invention, the cooling fan is attached to the inner surface of the intake port, the flange is formed at the end of the first side plate, and the exhaust port is located inward of the flange so as to avoid the flange. And an air guide plate extending obliquely inward from the rear portion of the cooling fan on the inner surface of the first side plate to the outer end edge of the exhaust port. . Therefore, the cooling fan is attached to the inner surface of the intake port of the first side plate, and the air guide plate diagonally extends from the first side plate to the outer edge of the exhaust port of the rear plate that is provided near the inside of the housing. Is provided, the fluid resistance is reduced, the forced convection wind speed is increased, and the exhaust airflow is deflected away from the machine tool.

In the control panel according to the third aspect of the present invention, the unit guide is located above and below the intake port and the exhaust port to horizontally partition the corner portion of the housing, and a pair of upper and lower unit guide parts provided with rail members. Connecting the unit guide parts, and forming a fan hole corresponding to the intake port of the first side plate of the housing in the front, and a side wall part fixed to the inner surface of the first side plate, and a side wall. The air guide plate is formed by cutting and bending to the rear of the fan hole of the portion, and the front surface portion is formed by bending from the front edge of the side wall portion and provided with an attachment / detachment opening. Therefore, the cooling fan is attached to the inner surface of the intake port of the first side plate, and the air guide plate obliquely extends from the first side plate to the outer edge of the exhaust port of the rear plate that is provided near the inside of the housing. Is provided, the fluid resistance is reduced, the forced convection wind speed is increased, and the exhaust airflow is deflected away from the machine tool.

In the control panel according to the fourth aspect of the present invention, the case is divided into a front part and a rear part by a partition plate, a dustproof compartment is formed on the front part, and a ventilation compartment is formed on the rear part. The switching unit is accommodated along the first side plate, the partition plate and the back plate that form the ventilation section are provided with the exhaust port of the ventilation section, and the ventilation unit is installed in the ventilation section while avoiding the exhaust port. A heat transfer plate for heat exchange consisting of a longitudinal internal air flow passage whose ends are sealed and an external air flow passage whose upper and lower ends are opened alternately located with the internal air flow passage, and arranged at the end of the ventilation section. An external air fan that is installed to forcibly cool the external air flow path and an internal air fan that is disposed in an internal air vent that communicates the dust-proof compartment with the upper and lower portions of the internal air flow path and that forcedly circulates the internal air flow path and the dust-proof compartment are provided. It is a feature. Therefore, the heat transfer plate having the outside air and the inside air flow path for heat exchange, the inside air and the outside air fan are disposed inside the ventilation section formed on the back side of the housing, avoiding the exhaust port of the ventilation section, and thus switching is performed. An output terminal block can be arranged in the ventilation section adjacent to the unit,
The heat generating semiconductor element and the printed circuit board in the dustproof compartment are indirectly cooled.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. In the figure, 101 is a control panel, 1 is its housing, 2 is a left side plate as a first side plate, 3 is a front door as a second side plate, and 4 is the front and rear of the case 1. A partition plate, 5 is a back plate, and 6 is a top plate. The control panel 101 is installed so that one side plate is adjacent to a machine tool such as an electric discharge machine. In this embodiment, as shown in FIG. 6, the left side plate 2 is installed adjacent to the machine tool 102 with a space for intake. A dustproof section 90 is formed between the front door 3 and the partition plate 4, and a ventilation section 91 is formed between the partition plate 4 and the back plate 5. Flange 2A is formed at the front and rear ends of the left side plate 2 to ensure rigidity, and a slit-shaped intake port 2B is formed in the front side. An exhaust port 4A having a vertically long rectangular shape is formed on the left side of the partition plate 4. The exhaust port 4A is arranged near the inside of the housing, avoiding the flange 2A.

Reference numeral 10 denotes a unit guide, which is a pair of unit guide portions 11 which are located above and below the intake port 2B and the exhaust port 4A and horizontally partition the corners of the dustproof compartment 90, and side wall portions which connect the unit guide portions 11 to each other. 12 and this side wall 12
The air guide plate 13 is formed by cutting and bending from the front side, and the front surface portion 14 is formed by bending from the front edge of the side wall portion 12. A rail portion 11A is bent and formed at an edge of the unit guide portion 11 in the depth direction. Reference numeral 15 denotes a pair of rail members fixed to the inner surface of the unit guide portion 11, and a unit insertion groove 95 (FIG. 4) is formed between the rail member and the rail portion 11A. Reference numeral 12A is a fan hole provided in the front side of the side wall portion 12 corresponding to the intake port 2B. Reference numeral 12B is a slotted hole which is formed at the rear end and is provided to form the air guide plate 13. A part of the front surface portion 14 is cut out to form an attachment / detachment opening 14A. The side wall portion 12 of the unit guide 10 configured as described above is closely fixed to the inner surface of the left side face plate 2 with the screw 16. Further, the rear end of the unit guide portion 11 on the lower side is closely attached to the partition plate 4.
The projecting portion 11B formed on the bottom is fitted to the lower end of the exhaust port 4A.

A switching unit 51 is composed of the following parts. Reference numeral 17 is a unit panel having a front plate 17A, bent edges 17B formed on three sides, and an opening 17C in the center. Reference numeral 18 denotes a main heat sink arranged inside the unit panel 17, which is a base plate 18A.
And a number of parallel plate-shaped heat radiation fins 18 extending in the horizontal direction
Have B. A collar 21 and a bush 22 are combined and fitted around the base plate 18A. The main heat sink 18 is electrically insulated and fixed to the unit panel 17 via a screw 23 penetrating the bush 22. A packing 24 is arranged between the entire circumference of the base plate 18A and the unit panel 17, and the opening 17C is hermetically closed by the main heat sink 18. Reference numeral 19 is an auxiliary heat sink having a plurality of L-shaped cross sections, and its first leg 19A is thermally connected to the cooling surface of the base plate 18A (opposite to the radiation fins 18B) via the screw 20. Connected and fixed, the second leg 19B projects into the dustproof compartment 90 through the opening 17C. Reference numeral 52 denotes a plurality of semiconductor elements, which are heat-generating semiconductor components, which are thermally connected and fixed to the second leg 19B by screws 25. Reference numeral 53 is a printed circuit board, on one side of which electronic parts 54 and 55 for the snubber circuit and the gate drive circuit are soldered. The printed circuit board 53 is fixed to the unit panel 17 via a mounting member 26. Terminal 52 of semiconductor element 52
A is inserted and soldered from the solder side of the printed circuit board 53. 56A is a soldered output connector socket, and 56B is the same plug.

The switching unit 51 is inserted into the upper and lower unit insertion grooves 95 of the unit guide 10 and is fixed to the front surface portion 14 via a screw 28 at a front plate 17A portion that closes the front surface attachment / detachment opening 14A. Packing 27 is provided on the upper and rear sides of the bent edge 17B of the unit panel 17.
Are attached, and the gaps between the unit panel 17, the partition plate 4, and the upper unit guide 11 are airtightly closed. As a result, the inside of the unit guide 10 is separated from the dustproof compartment 90, and the ventilation compartment 92 is provided with the intake port 2B and the exhaust port 4A.
Is formed. In addition, the fan hole 1 matching the intake port 2B
A cooling fan 57 is arranged on the inner surface of 2A. Further, the back plate 5 is provided with a slit-shaped exhaust port 5A corresponding to the exhaust port 4A.

Reference numeral 30 designates an exhaust port 4A, 5 in a ventilation compartment 91.
It is a heat transfer plate for heat exchange, which is arranged avoiding A. The heat transfer plate 30 has a plurality of partition walls 30A formed by bending a thin metal plate into a corrugated shape, and has mounting flanges 30B at both ends.
Is formed and is airtightly fixed to the partition plate 4. Divider 4
Sealing members 30 </ b> C seal the upper and lower ends of the inside of the groove of the heat transfer plate 30 whose sides are open. As a result, a large number of inside air passages 93 are formed between the heat transfer plate 30 and the partition plate 4, and the inside and outside of the inside air passages 93 are located alternately and the upper and lower ends are opened between the back plate 5 and the outside. An air flow path 94 is formed. A first inside air vent 4B communicating with the inside air passage 93 is provided above and below the partition plate 4.
And a second inside air vent 4C is provided. An inside air fan 61 is provided in the first inside air vent 4B via a fan panel 31. The top of the ventilation section 91 is the top plate 6.
The notch portion 6A communicates with the fan duct 32, and the lower portion communicates with the outside air inlet (not shown). An outside air fan 62 is arranged on the inner surface of the fan hole 32A of the fan duct 32.

On the control panel 101, two switching units 51 are mounted for parallel operation. The unit guide 10 into which the above-mentioned unit 51 is inserted is fixed to the inner surface of the left side face plate 2 in close contact with each other vertically. Reference numeral 58 denotes an output terminal block, which is disposed in the ventilation section 91, is located in the middle of the upper and lower two switching units 51, and is attached to the partition plate 4. As shown in FIG. 5, the output terminal block 58
Has a plurality of conductors 58A, an interphase wall portion 58B for insulating and partitioning the conductor 58A, and a central wall portion 58C for fixing the conductor 58A and partitioning the power source side and the load side. In order to wire the output terminal block 58 from inside the dustproof compartment 90,
A wiring hole 4D is formed in the partition plate 4. Wiring hole 4 above
With a plurality of in-board cables 59 passing through D, the output connector plugs 56B and the conductors 5 of the two switching units 51 are connected.
8A is wire-connected. The in-board cable 59 has an appropriate extra length (slack) so that the switching unit 51 can be pulled out to an intermediate position and the output connector plug 56B can be pulled out.

Reference numeral 33 is the wiring hole 4D and the output terminal block 58.
Is a box member for covering the power source side of the. The cutout portion 33A of the box member 33 is configured to exactly surround the periphery of the central wall portion 58C of the output terminal block 58. This allows
The wiring hole 4D is dust-tightly sealed while the in-board cable 59 is wired and connected. The power supply cable 60, which is wired and connected to the machine tool, is drawn in through the cable hole 2C of the left side plate 2 and connected to the load side of the conductor 58A exposed from the box member 33. Work holes 5B are provided in the back plate 5 for the above work. Reference numeral 7 is a lid plate that closes the work hole 5B, and has a slit-shaped exhaust port 7A similar to the exhaust port 5A of the back plate.

Reference numeral 63 is a CRT housed in the upper part of the switching unit 51, and is attached to a gantry 34 that is laterally extended to the housing 1. Reference numeral 64 denotes an operation unit equipped with a CRT transparent window attached to the front door 3, a sheet key switch, and the like. Although not shown, other units and printed circuit boards are housed in the dustproof compartment 90. Since the heat transfer plate 30 for indirect air cooling is arranged in the ventilation section 90 having a narrow depth on the back surface as described above, the CR is used.
It becomes easy to arrange the T, the operation unit, other units and the printed circuit board in the panel and approach them from the front side.

Next, the operation of the switching unit 51 configured as described above will be described. Printed circuit board 5
The semiconductor element 52 is switched by the control signal from the semiconductor device 3. Most of the heat generated in the semiconductor element 52 at that time is conducted to the sub heat sink 19, and then to the heat radiation fin 18B from the base plate 18A of the main heat sink 18. Cooling fan 5 arranged in fan hole 12A
By the operation of 7, the forced convection is carried out as schematically shown by arrows a1 to a4 in FIG. The outside air a1 is blown into the radiating fin 18B in front of the heat sink 18 at a substantially right angle as indicated by an arrow a2, and then flows rearward along the radiating fin 18B. A part of the airflow goes out of the heat radiation fin 18B as indicated by an arrow a3, but is pushed back by the air guide plate 13 and enters the rear heat radiation fin 18B. Exhaust port 4
The exhaust flow flowing from A through the ventilation section 91 and discharged from the exhaust port 5A to the outside of the housing 1 is deflected substantially along the air guide plate 13 as indicated by an arrow a4. Heat is transferred from the radiation fins 18B to the outside air by the forced convection, and the radiation fins 18B are cooled.

Since most of the heat generated from the semiconductor element 52 is discharged to the outside of the housing 1 as described above, less heat is dissipated from the switching unit 51 into the dustproof compartment 90. Since the outside air is pushed into the radiating fins 18B of the main heat sink 18 so as to form a collision jet, the outside air reaches and reaches the outside surface of the base plate 18A, which is a higher temperature portion, and the temperature difference from the outside air is generated. Large heat dissipation. The outside air warmed on the upstream side flows to the downstream side of the main heat sink 18, but the airflow a3 is joined and the air passage is narrowed by the air guide plate 13, so the wind speed is high and turbulent flow is promoted. The heat transfer rate is improved. As described above, the cooling performance of the heat sink 18 can be improved. Further, even if the semiconductor element 52 causes a dielectric breakdown, the heat sinks 18, 19 are prevented from applying an abnormal voltage to the housing 1 side.
Are installed electrically isolated.

The two switching units 51 are vertically arranged in close contact with each other along the left side plate 2, but since the cooling fan 57 sucks and discharges the exhaust flow in the horizontal direction, they adversely affect each other. Absent. That is, the upper switching unit 51 is not heated by the heat generation of the lower switching unit 51. Also, for the same reason,
The CRT 63 can be arranged above the switching unit 51 and close to the machine body side (left side face plate 2 side). As a result, it is possible to easily perform an electrical operation from the working position of the machine body and make the CRT screen easy to see. Also,
The intake / exhaust flow of the ventilation compartment 92 does not hit the operator standing in front of the front door 3 and does not cause discomfort. further,
As described above, since the two switching units 51 are mounted at the position closest to the machine body side, the length of the power feeding cable 60 can be shortened and the attenuation of the peak output current due to the cable impedance can be reduced.

The exhaust flow a4 discharged from the exhaust port 5A to the outside of the housing 1 is deflected by the air guide plate 13 so as to be distant from the machine tool adjacently installed on the left side face plate 2 side. Therefore, it is possible to eliminate the adverse effect of exhaust heat such as thermal strain on the machine tool. Further, the air guide plate 13 smoothly deflects the air flow in the ventilation compartment 92 without colliding with the corner between the left side plate 2 and the left end of the partition plate 4.
Therefore, the fluid resistance can be reduced, and the cooling fan 57 can be operated in the high air volume region. Further, since the cooling fan 57 can be installed in the dead space formed within the width of the flange 2A of the left side plate 2, the board width can be reduced.

Next, the indirect air cooling of the dustproof section 90 will be described. By the operation of the inside air fan 61, the warmed inside air in the dust-proof compartment 90 is sucked from the upper first inside air vent 4B as shown by the arrow b (FIG. 3), and inside the inside air passage 93 of the heat transfer plate 30. Is split and returned to the inside of the dustproof compartment 90 again from the second inner air vent 4C at the bottom. By the operation of the outside air fan 62, the outside air is sucked from the outside air intake port in the lower part of the ventilation section 91 as shown by the arrow c, and is diverted in the outside air flow path 94 to the outside of the board from the fan duct fan hole 32A on the top plate 6. Is discharged. Due to the forced convection in the inside air and outside air passages 93 and 94, heat exchange is performed via the heat transfer plate 30 and the dustproof section 90 is indirectly cooled. As described above, most of the generated heat amount of the switching unit 51, which has the largest heat generation amount, is dissipated to the outside of the panel from the main heat sink 18 located in the ventilation compartment 92, and thus the heat transfer plate 30, the inside air and outside air fans 61, 62. Can be small.

The ventilation compartment 92 is the switching unit 51.
Is formed by an integral unit guide 10 into which the air guide plate 13 can be detachably inserted, and the air guide plate 13 is also integrally cut and bent from the unit guide. Since the number of constituent members is small, an integration error caused by combining a plurality of constituent members can be eliminated, and production management can be facilitated. Further, the cooling fan 57 and the like can be collectively screwed and fixed to the inner surface of the left side plate 2, so that a plurality of constituent members can be respectively welded to the housing 1 or joined or assembled by screwing. The productivity of control panel assembly can be improved. In addition, the projection 11B at the lower end of the unit guide 10
Is fitted to the lower edge of the exhaust port 4A of the partition plate 4, so that the weight of the switching unit 51 can be supported without welding or screwing the lower unit guide portion 11 for reinforcement.

Since the output terminal block 58 arranged by utilizing the space inside the ventilation section 90 is located close to and equidistant from the two switching units 51 arranged in close contact with each other, the cable inside the panel is The length of 59 can be short and the same. Therefore, it is possible to prevent the occurrence of current imbalance due to uneven wiring impedance. Further, since the output terminal block 58 is close to the left side plate 2 on which the machine tool is installed adjacently, the length of the power supply cable 60 can be shortened. To connect the power supply cable 60, the cover plate 7 is removed and the dustproof section 9 is connected.
Since it can be done from outside 0, it is possible to prevent accidental entry of foreign matter into the dustproof section 90 during the connection work.

In the above embodiment, the switching unit 51 using the semiconductor element 52 has been described.
A semiconductor power module may be used. in this case,
The sub heat sink 19 is unnecessary, and the semiconductor power module may be directly fixed to the base plate 18A of the main heat sink 18. Further, as the radiation fins 18B of the main heat sink 18, various types such as a pin fin type can be used as long as they do not prevent forced convection by the cooling fan 57.

[0026]

As described above, according to the first aspect of the present invention, the unit guides arranged at the corners of the first side plate and the rear plate, and the switching inserted in the unit guides. The heat sink, which forms a ventilation compartment with the unit panel of the unit and is placed in the ventilation compartment, is forcibly cooled by the outside air flowing from the intake port of the first side plate to the exhaust port of the back plate by the cooling fan. Since the exhaust heat is horizontally discharged to the outside of the housing, the amount of heat generated in the panel is reduced.

Further, according to the second aspect of the invention, the cooling fan is attached to the inner surface of the intake port of the first side plate, and the outside of the exhaust port of the rear plate formed near the inside of the housing from the first side plate. Since the air guide plate extending obliquely to the end edge is provided, the fluid resistance is reduced, the wind velocity of forced convection is increased, and the main heat sink can be efficiently cooled. Further, the exhaust airflow is deflected in the direction away from the machine tool, and there is an effect that it is possible to prevent the machine tool from being adversely affected by heat.

According to the third invention, the switching unit can be detachably inserted into the ventilation compartment, and
Since the air guide plate is formed by cutting and bending integrally and is formed by the integrated unit guide screwed and fixed to the inner surface of the first side plate, the productivity of the case production and the control panel assembly is improved.

According to the fourth aspect of the invention, the heat transfer plate having the outside air and inside air passages for heat exchange, the inside air and the outside air fan are provided on the back side of the housing while avoiding the exhaust port of the ventilation section. Therefore, it is possible to arrange the output terminal block in the ventilation section adjacent to the plurality of switching units, and indirectly to generate the heat-generating semiconductor element and the printed circuit board in the dust-proof section without interfering with the forced air cooling of the switching unit. It has the effect of cooling.

[Brief description of drawings]

FIG. 1 is a front view of a main part of a switching unit portion of a control panel according to the present invention, which is partially broken (a cross-sectional view taken along arrow I-I in FIG. 3).

FIG. 2 is a horizontal cross-sectional view of a main part of a switching unit portion of a control panel according to the present invention as viewed from an arrow II-II in FIG.

FIG. 3 is a vertical cross-sectional view of a part of the upper part of the control panel according to the present invention, taken along arrow III-III in FIG.

FIG. 4 is a perspective view of a unit guide according to the present invention.

5 is a horizontal cross-sectional view of a main part of the output terminal block portion according to the present invention as viewed from an arrow VV in FIG. 3. FIG.

FIG. 6 is a front view showing an installed state of the control panel according to the present invention.

[Explanation of symbols]

1 housing, 2 left side plate, 2B intake port, 3 front door,
4 partition plates, 4A exhaust port, 4B first inside air intake port,
4C Second inside air intake port, 5 back plate, 5A exhaust port, 1
0 unit guide, 11 unit guide part, 11B
Protrusions, 12 sidewalls, 13 air guide plates, 15 rail members, 17 unit panels, 17A front plate, 1
7C opening, 18 main heat sink, 18A base plate, 18B heat radiation fin, 19 double heat sink,
30 heat transfer plate, 33 box member, 51 switching unit, 52 semiconductor element, 53 printed circuit board, 56B
Output connector plug, 57 cooling fan, 58 output terminal block, 59 cable inside panel, 60 power supply cable, 61
Inside air fan, 62 Outside air fan, 63 CRT, 64
Operation unit, 101 control panel, 102 machine tools.

Claims (4)

[Claims] 1. A control panel which is hermetically sealed from a front door in a dustproof manner and has a casing provided with first and second side plates, wherein an intake port is formed in the first side plate. An exhaust port formed on the back surface of the housing and a corner portion in the housing are partitioned so as to surround the intake port and the exhaust port, and a detachable opening is formed on the front surface of the housing and the second side plate side. A unit guide provided with, a unit panel that is inserted into the unit guide, and that divides the corners of the housing as ventilation compartments, and is attached so as to close the opening formed in the unit panel. A heat sink disposed in a ventilation compartment, a semiconductor element attached to the base plate of the heat sink, a switching unit including a printed circuit board electrically connected to the semiconductor element, A control board provided with a cooling fan, which is disposed at an intake port and which flows between the intake port and the exhaust port and forcibly convects the outside air to the heat radiation fins of the heat sink. 2. A cooling fan is attached to an inner surface of the intake port, a flange is formed at an end portion of the first side plate, and the exhaust port is bored inward to avoid the flange. The control panel according to claim 1, further comprising: an air guide plate that extends obliquely inward from a rear portion of the cooling fan on the inner surface of the first side plate to an outer end edge of the exhaust port. 3. The unit guide includes a pair of upper and lower unit guide portions provided with rail members, and a unit guide portion which is located above and below the intake port and the exhaust port to horizontally partition a corner portion of the housing. A fan hole corresponding to the intake port of the first side plate of the housing is formed in the front, and a side wall part fixed to the inner surface of the first side plate and the side wall part The control panel according to claim 1 or 2, comprising an air guide plate formed by cutting and bending at the rear of the fan hole, and a front surface part formed by bending from the front edge of the side wall part and provided with an attachment / detachment opening. 4. The front side and the back side of the case are partitioned by a partition plate, and the front side has a dust-proof section and the back side has a ventilation section, and the first side of the case. A switching unit is accommodated along the face plate, an exhaust port of the ventilation section is formed in the partition plate and the back plate that form the ventilation section, and the ventilation unit is disposed in the ventilation section while avoiding the exhaust port. A heat transfer plate for heat exchange consisting of a vertical internal air flow passage sealed with the internal air flow passage and an external air flow passage whose upper and lower ends are opened alternately with the internal air flow passage, and arranged at the end of the ventilation section. An outside air fan installed for forced air cooling of the outside air flow passage, and an inside air fan disposed in an inside air ventilation port that communicates the dust-proof compartment with the upper and lower portions of the inside air passage and forcibly circulates the inside air passage and the dust-proof compartment. The control panel according to any one of claims 1 to 3, wherein the control panel is a control panel.