Abstract:
It is an object of the invention to achieve an improvement in the operating reliability of a cooking controller and to extend its lifetime. A cooking controller ( 18 ) is provided within a casing ( 21 ), and an insulating material ( 22 ) for blocking out the heat emitted from an oil vat ( 3 ) is provided on the wall of the casing ( 21 ) on the side of the oil vat ( 3 ). A top opening ( 23 ) and a bottom opening ( 24 ) are provided in the top wall and bottom wall of the casing ( 21 ), and a cooling fan ( 25 ) is provided at an intermediate position within an air circulation route ( 29 ) from the bottom opening ( 24 ) to the top opening ( 23 ). The cooling fan ( 25 ) is operated and the generated flow of the air passing between the openings cools and insulates the heat emitted from the oil vat ( 3 ) towards the cooking controller ( 18 ). Thus, temperature increases within the cooking controller ( 18 ) can be inhibited, and operational reliability and the lifespan of the cooking controller ( 18 ) can be increased.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an industrial fryer for cooking foods, which is provided with a plurality of oil vats. 
     2. Description of Related Art 
     Conventionally, fryers provided with a plurality of oil vats are known as industrial fryers. An example of a three-vat type fryer provided with three oil vats is shown in FIGS. 6 and 7. In this fryer  1 , three fryer units  1   a,    1   b,  and  1   c  are provided together in a row within a main casing. The fryer units  1   a,    1   b,  and  1   c  are each provided with, for example, an oil vat  3  for containing cooking oil (hereinafter, simply “oil”), two pulse burners  4  for heating the oil within the oil vat  3 , a cooking controller  18 , and a heating controller  19 , and basically share the same configuration. 
     The control portion of the fryer  1  is made up of the cooking controller  18 , which is for setting the cooking time and the temperature in accordance with the cooking program via a control panel, and the heating controller  19 , which is for controlling the operation of the pulse burners  4  so that the temperature of the oil is maintained at the temperature designated by the cooking controller  18 . The cooking controller  18  is provided at the top of the front side of the apparatus for easy control by the operator, and is positioned adjacent to the oil vat  3  due to the structure of the fryer  1 . Therefore the cooking controller  18  is heated by the heat emitted from the oil vat  3 . Accordingly, to prevent poor performance and a reduced lifetime due to overheating of the cooking controller  18 , an insulting material was conventionally provided between the oil vat  3  and the cooking controller  18 . Alternatively, the cooking controller  18  was cooled and insulated by the flow of air resulting from the force of the natural draft which was generated within the casing housing the cooking controller  18 . 
     In the three-vat type fryer depicted in FIGS. 6 and 7, the cooking controller  18  of the fryer unit  1   b  in the middle receives both the heat emitted from the left and right side oil vats  3 , but as for the fryer units  1   a  and  1   c,  it is not such a problem. Thus, there was the risk that overheating could not be sufficiently prevented with this conventional configuration. 
     It is an object of the fryer of the present invention to solve this problem, and to achieve increased operational reliability of the cooking controller and to extend its lifetime. 
     SUMMARY OF THE INVENTION 
     A fryer of the present invention for solving the above problem, is a multi-vat fryer in which at least three fryer units are provided in a row, each fryer unit being provided with an oil vat for containing cooking oil, a heating control means for controlling the heating of the cooking oil, and a cooking controller for carrying out settings such as temperature settings and a cooking program while sending a control signal to the heating control means, 
     wherein the cooking controller of each fryer unit includes a connection detecting means for detecting whether a cooling fan for preventing an electronic circuit board in the cooking controller from overheating is connected, and a driving means for driving the cooling fan; 
     and the cooling fan is provided only in the cooking controller of a specific fryer unit of the plurality of fryer units. 
     A feature of a fryer of the present invention is that in the fryer, three fryer units are provided in a row, and the cooling fan is provided only for the cooking controller of the middle fryer unit. 
     A feature of a fryer of the present invention is that in the fryer, the cooking controller is provided with a control display portion for controlling and displaying temperature settings and the cooking program, for example, and 
     the control display portion displays whether the cooling fan detected by the connection detecting means is connected. 
     With the fryer of the present invention having the above configuration, the heating control means heats cooking oil in the oil vat based on the cooking program and/or temperature setting set by the cooking controller. If a cooling fan is connected, the cooking controller detects the connection with the connection detecting means and drives it with the driving means. Thus, simply by connecting a cooling fan to a specific cooking controller to be prevented from overheating, the cooling fan is appropriately driven and cools and insulates against the heat emitted from the oil vats. Moreover, to switch between driving and not-driving the fan, it is unnecessary to perform troublesome settings and maintenance such as setting the status of the fan connection at each cooking controller or dividing the specifications for the cooking controllers to which the cooling fan is connected into “fan-connected type” and “no-fan-connected type” when manufacturing. 
     With the fryer of the present invention, three fryer units are provided in a row, and the cooking controller of the middle fryer unit is heated by the heat emitted from the oil vats of the left and right fryer units, but it is cooled and insulated by the cooling fan, and thus does not become particularly hot. 
     With the fryer of the present invention, the connection detecting means recognizes whether the cooling fan is connected, and this is displayed on the control display portion provided for the cooking controller. 
     With the fryer of the present invention, the cooling fan is controlled according to the temperature of the cooking controller, which is detected by the temperature sensor. This means that the cooling fan can be controlled so that it only operates when said detected temperature is above a specific value, although the temperature of the cooking controller may change due to the environment surrounding the fryer or how the fryer is used. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional view seen from the side of the casing housing the cooking controller for an embodiment of the present invention. 
     FIG. 2 is a schematic lateral cross-sectional view of the middle fryer unit of a three-vat type fryer for the present embodiment. 
     FIG. 3 is a cross-sectional view of the casing housing the cooking controller for the present embodiment seen from above. 
     FIG. 4 is a diagram illustrating the method of connection between the cooking controller and the cooling fan via connectors according to the present embodiment. 
     FIG. 5 is a diagram illustrating the display that is shown on the display portion of the cooking controller when the cooking controller of the present embodiment is activated. 
     FIG. 6 is a front view of a three-vat type fryer for the conventional example and the present embodiment. 
     FIG. 7 is a top view of a three-vat type fryer for the conventional example and the present embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A preferred embodiment of the fryer of the present invention is described below with reference to FIGS. 1 to  7 , further clarifying the configuration and operation of the present invention as described above. 
     FIG. 6 is a front view of a three-vat type fryer, and FIG. 7 is a top view of the three-vat type fryer. The front and top views of the fryer of the present embodiment are identical to those of the conventional fryer. 
     A fryer  1 , which is a three-vat type fryer including three vats, is provided with three fryer units  1   a,    1   b,  and  1   c  arranged together in a row within a main casing. The fryer units  1   a,    1   b,  and  1   c  are each provided with, for example, an oil vat  3  for containing oil, two pulse burners  4  for heating the oil within the oil vat  3 , a cooking controller  18 , and a heating controller  19 , and basically share the same configuration. The following description is of the fryer unit  1   b  in the middle, and because the other fryer units  1   a  and  1   c  have a common configuration with the fryer unit  1   b,  their explanation will be omitted. 
     FIG. 2 illustrates the internal structure of the middle fryer unit  1   b,  and is a schematic lateral cross-sectional view cut along the segmented line A—A in FIGS. 6 and 7. 
     The oil vat  3 , the pulse burners  4  and an oil cleaner  5  for filtering the oil in the oil vat  3  are provided inside a main casing  2  of the fryer unit  1   b.  The oil vat  3  is filled with oil for deep frying foods, and the pulse burners  4  serve as the heating means for heating the oil. An oil temperature sensor  6  for detecting the temperature of the oil is provided within the oil vat  3 . 
     The pulse burners  4  have a combustion chamber  7  formed within the oil vat  3  and a mixing chamber  41  that is in communication with the combustion chamber  7  outside the oil vat  3 . An air chamber  8  is provided around the mixing chamber  41 . A gas pipe  12  for supplying the fuel gas is connected to the mixing chamber  41  and provided with, from the upstream side, an intake electromagnetic valve  9 , a main electromagnetic valve  10 , and a gas governor  11 . Combustion air can be supplied to the air chamber  8  by an air supply pipe  14  provided with a fan  13 . 
     Furthermore, a tail pipe  15  is connected to the combustion chamber  7  within the oil vat  3 , and outside the oil vat  3  the tail pipe  15  is connected to an exhaust duct  17 , which opens to the outside, via a decoupler  16 . 
     The bottom wall of the oil vat  3  slopes diagonally downward from the rear of the fryer unit  1   b  toward the front, and a discharge duct  39  for discharging oil is provided at the side wall of the bottommost portion thereof. A discharge opening  40  is attached to the tip of the discharge duct  39 . The oil cleaner  5  is made up of an oil tank  35  for receiving dirty oil from the oil vat  3  through the discharge opening  40 , an oil filter (not shown in the drawings) stretched in a sheet-like fashion slightly above the bottom portion of the oil tank  35 , an oil pump  36  for taking up oil that has passed through the oil filter and returning it into the oil vat  3 , and an oil pipe  37  which forms a flow path for returning this oil. The oil cleaner  5  itself is provided only in the fryer unit  1   b,  and oil used and dirtied in the fryer units  1   a  and  1   c  also drops into the oil tank  35  via a discharge duct (not shown in the drawings), and is filtered by the oil cleaner  5 . The oil is then returned to each of the oil vats  3  using a return pipe (which is not shown in the drawings), which branches from the oil pipe  37  at a position downstream from the oil pump  36  and is connected to the oil vats  3  of the fryer units  1   a  and  1   c.    
     With the above-described fryer unit  1   b,  oil is filled into the oil vat  3 , and once the oil has been heated, foods are placed into a basket (not shown) and submerged into the oil vat  3  to be cooked. The oil in the oil vat  3  is heated by the heat from the outer wall of the combustion chamber  7  and the tail pipe  15 , and the foods are cooked by the hot oil. 
     The control portion of the fryer unit  1   b  will be described next. At the top portion of the front wall of the main casing  2 , the cooking controller  18  is provided within a casing  21 . The cooking controller  18  is for setting the cooking times and the set temperature according to the cooking program. At the bottom portion of the front wall of the main casing  2 , the heating controller  19  is provided. The heating controller  19  is for controlling the operation of the pulse burners  4  so that the temperature of the oil is maintained at the set temperature instructed by the cooking controller  18  in accordance with the detected temperature obtained form the oil temperature sensor  6 . The primary part of the cooking controller  18  is configured by a microcomputer, and the cooking controller  18  is provided with a display portion  20  for displaying the set temperature and the cooking time, for example, and control switches  38  for controlling its operation. 
     The cooking controller  18  is adjacent to the oil vat  3 , so that it is necessary to prevent the temperature of an electronic circuit board  28  within the cooking controller  18  from rising due to the heat emitted from the oil vat  3 . Particularly in a three-vat type fryer such as fryer  1 , the cooking controller  18  in the middle receives the heat released from the oil vats  3  of the left and right fryer units  1   a  and  1   c,  and thus its temperature increases drastically. For that reason, a cooling fan  25  for cooling and insulating against the heat released from the oil vats  3  is provided only in the cooking controller  18  of the middle fryer unit  1   b.    
     It should be noted that there are electrical components provided inside the heating controller  19  as well, but the heating controller  19  is provided away from the oil vat  3 , and thus is not heated as much. 
     The cooling system of the cooking controller  18  will be explained next with reference to FIGS. 1 and 3. FIG. 1 is a cross-sectional view of the casing  21  housing the cooking controller  18  for the middle fryer unit  1   b  seen from the side. FIG. 3 is a cross-sectional view of the casing  21  housing the cooking controller  18  seen from the top. 
     The cooking controller  18  is provided at the front within the casing  21 , with its control/display panel, facing diagonally upward. An insulating material  22  for blocking out heat from the oil vat  3  is provided at the wall of the casing  21 , facing the oil vat  3 . A top opening  23  and a bottom opening  24  are provided in the top and bottom walls of the casing  21 , and the cooling fan  25  is provided at an intermediate location in an air circulation route  29  from the bottom opening  24  to the top opening  23 . When the cooling fan  25  spins, the flow of air from the bottom opening  24  to the top opening  23  generated by the force of the natural draft can be accelerated, and thus the cooling and insulating effect can be further increased. 
     The cooling fan  25  is connected to the cooking controller  18  via connectors  26   a  and  26   b.  The cooking controller  18  checks the connection of the connectors  26   a  and  26   b;  and when they are connected, it supplies electrical power to the cooling fan  25  and simultaneously displays a mark indicating the connection on the display portion  20 . The cooking controller  18  also detects whether the cooling fan  25  is stopped when they are connected. 
     On the other hand, although the electronic circuit board  28  in the cooking controllers  18  for the left and right fryer units  1   a  and  1   c  is also heated by the heat emitted from the oil vats  3 , heat insulation by the insulating material  22  and the flow of air from the bottom opening  24  to the top opening  23  utilizing the force of the natural upward draft which is generated within the casing  21  together provide a sufficient cooling effect and thus the cooling fan  25  is not necessary. 
     The method for detecting whether the connectors are connected is described next with reference to FIG.  4 . 
     The cooking controller  18  and the connector  26   a  are connected by a wire  30   a  for supplying direct current for driving the cooling fan  25 , a stoppage detecting wire  31   a,  a GND wire  32   a,  and a connection detecting wire  33 . The cooling fan  25  (fan motor) and the connector  26   b  are connected by a wire  30   b  for supplying direct current for driving the cooling fan  25 , a stoppage detecting wire  31   b,  and a GND wire  32   b.  A short-circuit wire  34  is connected to the GND wire  32   b.    
     The cooking controller  18  is set to a HIGH level by the connection detecting wire  33 . When the cooking controller  18  is connected to the cooling fan  25  by establishing a connection between the connector  26   a  and the connector  26   b,  the connection detecting wire  33  is connected to the GND wire  32   b  and shifts to LOW level. Therefore, the connection with the cooling fan  25  is detected. 
     To prevent overheating of the cooking controller  18 , it is unnecessary to provide cooling fans  25  for all the cooking controllers  18 , and the cooking controller  18  detects whether it is connected to a fan when the power is turned on, and displays the status of the connection on the display portion  20 . 
     FIG.  5 ( a ) illustrates the appearance of the display when the cooking controller  18  is started up if there is no connection; and FIG.  5 ( b ) illustrates the appearance of the display when the cooking controller  18  is started up if there is a connection. As can be understood from these diagrams, the cooling fan  25  is recognized as connected when the “#” signs are displayed on both sides of the display portion  20 . 
     A temperature sensor  27  is provided inside the cooking controller  18 , and it operates the cooling fan  25  when it detects a temperature of 60° C. or higher (and stops the cooling fan  25  when the temperature is below 60°). 
     The temperature within the cooking controller  18  changes depending on the environment around the fryer  1  and how the fryer  1  is used. Thus, it is possible to prevent energy from being wasted by stopping the cooling fan  25  for example when the fryer units  1   a  and  1   c  at the left and right of the fryer  1  are not in use, which means that the temperature within the cooking controller  18  does not become particularly elevated, and that cooling by the cooling fan  25  is unnecessary. 
     With the fryer  1  described above, the cooling fan  25  provided at the middle fryer unit  1   b  can cool the cooking controller  18 , which easily rises to high temperatures, and inhibit a rise in temperature, that will increase operation reliability and longer life can be achieved. 
     Further, since the cooking controller  18  automatically detects whether or not the connectors  26   a  and  26   b  are connected, in other words whether the cooling fan  25  is connected to the cooking controller  18 , it is not necessary to set whether or not there is a cooling fan at each cooking controller and to separately manufacture cooking controllers with distinction of connecting to the cooling fan. Therefore, time-consuming maintenance and settings can be obviated. 
     As it is displayed whether the cooling fan  25  is connected on the display portion  20  when the cooking controller  18  is started up, it is easy to check whether the cooling fan  25  has been attached during factory shipments. 
     Furthermore, an unnecessary waste of energy can be prevented because the cooling fan  25  is not driven when cooling by the cooling fan  25  is not required. 
     The above description of embodiments of the present invention is not intended to limit the present invention, and it is of course possible to develop a variety of embodiments of the present invention within a scope that does not depart from the essential points of the present invention. 
     For example, in the present embodiment the cooling fan  25  was provided in the cooking controller  18  of the middle unit of a three-vat type fryer, but it is also possible to provide the cooling fan in fryers configured by a plurality of fryer units, such as four-vat type fryers and five-vat type fryers. In such a case, the cooling fan can be provided in cooking controllers sandwiched to the left and right by other fryer units. 
     Also, a pulse combustion type fryer is provided as an example in the present embodiment, however, there is no limitation to the heating method, and of course the fryer could also be of a type in which the oil vat is heated from the outside by a ceramic plate burner, for example. 
     As described in detail in the above, with the fryer according to claim  1  of the present invention, a cooling fan provided in a specific cooking controller which is expected to rise to high temperatures due to the heat emitted from an oil vat cools that specific cooking controller. As a result, it is possible to achieve increased operation reliability of the cooking controller and an increased cooking controller lifespan. Also, since the cooking controller automatically recognizes whether the cooling fan is connected, troublesome maintenance and settings at the production site can be obviated, and therefore the cost of manufacturing the fryer can be kept down. 
     Furthermore, with the fryer according to claim  2  of the present invention, in a three-vat fryer, the cooking controller for the middle fryer unit rises to temperature significantly higher than the left and right cooking controllers, however, it is cooled by a cooling fan, and thus increased operation reliability and an increased lifespan can be achieved Further, with the fryer according to claim  3  and  4  of the present invention, the control display portion displays whether the cooling fan is connected, which makes it possible to easily prevent the cooling fan from not being attached during factory shipment. 
     Moreover, with the fryer according to claim  5 ,  6 ,  7  and  8  of the present invention, the operation of the cooling fan is controlled according to the temperature within the cooking controller, so an unnecessary waste of energy can be prevented.