Abstract:
A cooling device with a first heat sink is provided with a blowing unit configured to introduce an ambient atmosphere into the cooling device. The first heat sink is provided with a plurality of fin portions, configured to perform heat exchange when contacted by the ambient atmosphere introduced by the blowing unit, and a mist collection unit horizontally projecting from the fin portions and configured to collect mists in the ambient atmosphere.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a cooling device, and more particularly, to a cooling device installed in a control panel of a machine tool. 
         [0003]    2. Description of the Related Art 
         [0004]    A large number of components with a heating portion are installed in a control panel of a machine tool. Depending on the states of the machine tool and its surroundings, the temperature inside the control panel may sometimes increase to damage the components thermally in the control panel. To suppress thermal damage, a method is generally known in which a cooling device, such as a cooling fan or heat exchanger, is installed in the control panel, thereby keeping the temperature low inside the control panel. 
         [0005]    The installation environment of the machine tool involves a large number of cutting fluid mists. Although closed control panels are frequently used to protect electric components from the cutting fluid mist atmosphere, they may sometimes allow penetration of the cutting fluid mists during prolonged operation. Typical cooling devices may be based on a method in which the efficiency of heat dissipation from a metallic control panel is increased by stirring an atmosphere in the control panel using a fan installed therein. Alternatively, the cooling devices may use a method, in which condensation in a control panel is prevented by exhausting heat in the control panel using a fan and a heat exchanger and dehumidifying the control panel. In a cooling device using a fan, cutting fluid mists in the control panel are gathered by the fan, so that the rate of failure of electric components in the path of air blown from the cooling device may increase, in some cases. 
         [0006]    Japanese Patent Application Laid-Open No. 2009-187977 discloses a prior art technique for a low-failure cooling device with a heat sink, based on the consideration of the installation environment of a machine tool. This cooling device can suppress adhesion of liquid or oil droplets even in an environment in which water or oil is scattered. For the cooling device disclosed in Japanese Patent Application Laid-Open No. 2009-187977, the problem mentioned above is solved by providing a plate-like member in the path of air leading to the heat sink, or a plurality of inlets such that the liquid or oil droplets cannot easily reach the interior of the cooling device. 
         [0007]    However, the cooling device disclosed in Japanese Patent Application Laid-Open No. 2009-187977 is configured so that the plate-like member forms lower, middle, and upper duct portions along which air introduced from outside is forcibly moved. Thus, there is a problem that the cooling device requires a large number of constituent components, costs high as a whole, and is bulky. 
       SUMMARY OF THE INVENTION 
       [0008]    Accordingly, in view of the above-described problems of the prior art, the object of the present invention is to provide a cooling device capable of suppressing adhesion of liquid or oil droplets despite its space-saving design, even in an environment in which water or oil is scattered. 
         [0009]    A control panel cooling device for a machine tool according to the present invention has a heat sink. The cooling device comprises a blowing unit configured to introduce an ambient atmosphere into the cooling device, and the heat sink comprises a plurality of fin portions, configured to perform heat exchange when contacted by the ambient atmosphere introduced by the blowing unit, and a mist collection unit horizontally projecting from the fin portions and configured to collect mists in the ambient atmosphere. 
         [0010]    The cooling device may comprise a heat exhaust unit and a heat sink of the heat exhaust unit may comprise the mist collection unit. 
         [0011]    The blowing unit may be installed on the exhaust port side of the heat sink. 
         [0012]    The cooling device may further comprise a tray in which droplets dripped from the heat sink are configured to be accumulated. 
         [0013]    Further, the cooling device may comprise a hole through which the droplets accumulated in the tray are configured to be discharged out of the control panel. 
         [0014]    According to the present invention configured as described above, there can be provided a time-saving cooling device with a low parts count, comprising a heat sink having a shape suitable for the collection of liquid and oil droplets. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The above and other objects and features of the present invention will be obvious from the ensuing description of embodiments with reference to the accompanying drawings, in which: 
           [0016]      FIG. 1  is a general view of a cooling device according to one embodiment of the present invention; 
           [0017]      FIG. 2  is an enlarged view of a heat sink according to the one embodiment of the invention; 
           [0018]      FIG. 3  is a sectional view of the cooling device according to the one embodiment of the invention; 
           [0019]      FIG. 4  is a view showing a flow of air current in the cooling unit according to the one embodiment of the invention; and 
           [0020]      FIG. 5  is a view showing a control panel fitted with the cooling device according to the one embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]      FIG. 1  is a general view showing a cooling device  1  according to one embodiment of the present invention. The cooling device  1  comprises a cooling unit  10  having a cutting fluid mist collection function and a cooling function and a heat exhaust unit  20  having a heat exhaust function. As shown in  FIG. 1 , the cooling unit  10  and the heat exhaust unit  20  are mounted on a bracket  30 , which is used for attachment to a control panel housing of a machine tool, inside and outside the housing, respectively. The heat exhaust unit  20  will be described in detail later. 
         [0022]    The cooling unit  10  comprises a heat sink  11 , cover  12 , a droplet guide  13 , a tray  14 , and a blowing unit  15 . As shown in  FIG. 1 , the heat sink  11 , the droplet guide  13 , and the tray  14  are mounted so as to be accommodated in the cover  12 . Further, the cover  12  is open at its upper end and the blowing unit  15  is attached to its lower end. 
         [0023]    The heat sink  11  has a function of cooling an ambient atmosphere introduced. therein by the blowing unit  15  and a function of collecting cutting fluid mists, which will be described later. Further, the droplet guide  13  has a function of introducing water condensed by cooling and dripped from the heat sink  11  and a cutting fluid collected by the mist collection function and dripped into the tray  14 . 
         [0024]      FIG. 2  is an enlarged view of the heat sink  11 . 
         [0025]    The heat sink  11  comprises fins  16  and a mist collection unit  17 . The fins  16  serve to increase the surface area to achieve a higher cooling effect. The mist collection unit  17  is given a shape suitable for cutting fluid mist collection. Dotted-line arrows of  FIG. 2  indicate a flow of air current produced as the atmosphere is made to flow in the heat sink  11  by the blowing unit  15 . Thus, the mist collection unit  17 , in the form of a plurality of projections between the fins  16 , is provided so as to deliberately resist a flow of air that passes between the fins  16 . In this way, the cutting fluid mists contained in the ambient atmosphere in the heat sink is condensed into droplets at portions hit by air and can be collected. 
         [0026]      FIG. 3  is a sectional, view of the cooling device  1  according to the present embodiment. 
         [0027]    In the cooling unit  10 , the heat sink  11  and a heat exchanger  18  are in contact with each other. The heat exchanger  18  is a conventional heat-pipe or Peltier heat exchanger, which uses the heat sink  11  to absorb heat from the ambient atmosphere introduced into the cooling unit  10  and exhaust the heat toward the heat exhaust unit  20 . Since the heat sink  11  is cooled to a temperature lower than the ambient temperature, it serves to cool and condense the ambient atmosphere. 
         [0028]    The droplet guide  13  introduces the water condensed and dripped from the heat sink  11  and the cutting fluid collected by the mist collection unit  17  and dripped into the tray  14 . The tray  14  connected with a hole  31  through which the dripped cutting fluid is gathered and discharged to the outside. The blowing unit  15  is a device for guiding the atmosphere in the control panel into the cooling unit  10 . 
         [0029]    The heat exhaust unit  20  comprises a case  21 , blowing unit  22 , and heat sink  23 . The heat sink  23  is mounted in proximity to the heat exchanger  18  and surrounded by the case  21 . The blowing unit  22  is attached to the outside of the case  21  so that heat from the heat exchanger  18  can be exhausted to the outside as the outside air is introduced into the heat sink  23  by operating the blowing unit  22 . While the case  21  has a function of efficiently discharging the outside air from the blowing unit  22  through the heat sink  23 , the case  21  and the blowing unit  22  need not always be provided, depending on the structure and heat exhaust efficiency of the heat sink  23 . Further, the blowing unit  22  may alternatively be attached directly to the heat sink  23  without using the case  21 . 
         [0030]      FIG. 4  shows a flow of air current in the cooling unit  10 . The ambient atmosphere to be introduced into the blowing unit  15  enters the heat sink  11  through its top and flows into the blowing unit  15 . Since the ambient atmosphere guided to the cooling unit  10  passes through the mist collection unit  17  in the heat sink  11  before flowing into the blowing unit  15 , the cutting fluid mists can be kept from adhering to the blowing unit  15 . Thus, the rates of failure of the blowing unit  15  and electric components (not shown) surrounding the air outlet of the blowing unit  15  due to the cutting fluid mists can be reduced. 
         [0031]    In general, the heat exhaust unit  20  is also provided with the blowing unit  22 , which is greatly influenced by the cutting fluid mists around the machine tool. In order to reduce the failure of the blowing unit  22  due to the cutting fluid mists, the heat sink  23  with the mist collection unit  17  may alternatively be installed in the heat exhaust unit  20 . 
         [0032]      FIG. 5  is a view showing the control panel  40  in which the cooling device  1  according to the present embodiment is installed. Since the control panel  40  is mounted so that the cooling unit  10  and the heat exhaust unit  20  are located inside and outside the control panel  40 , respectively, the temperature inside the control panel  40  can be reduced to facilitate the cutting fluid mists to be discharged out of the control panel.