Patent Publication Number: US-2020291845-A1

Title: Arrangement Structure of Cooling System in Construction Equipment

Description:
TECHNICAL FIELD 
     This invention relates to the technical field of arrangement structure of a cooling system equipped with a plural number of heat exchangers such as radiators etc., cooling fans, reservoir tanks etc., in construction equipment such as hydraulic shovels etc. 
     BACKGROUND TECHNOLOGY 
     In general, in the construction equipment such as hydraulic shovels etc., various heat exchangers such as a radiator to cool engine cooling water, an oil cooler to cool hydraulic oil, and an inter-cooler etc. to cool compressed air generated by a turbocharger are mounted, and also a cooling system equipped with a cooling fan that supplies cooling wind to these heat exchangers, and a reservoir tank etc. that store engine cooling water to handle volume change by heat expansion of engine cooling water are provided. 
     As the aforementioned reserve tank, traditionally an atmosphere—open type reserve tank connected to the radiator via radiator cap with a pressure adjustment function has been generally used. On the contrary, a pressurized sealed type reserve tank is known that is connected in parallel with the radiator in the cooling water circulation system between the radiator and an engine (for instance, refer to the Patent Literature 1). In case that such a pressurized sealed type reserve tank is used, part of engine cooling water is circulated via reservoir tank, and also the volume change by heat expansion of cooling water is absorbed by the phase part within said reservoir tank, hence air removal is performed within the cooling water circulation system, so compared with the reservoir tank of the aforementioned atmosphere—open type, there is an advantage in that it is superior in air bubble separation performance 
     On the other hand, for the construction equipment such as a hydraulic shovel, etc., as described before, a plural number of heat exchangers such as a radiator, an oil cooler, and an inter-cooler etc. are provided, but in this case, those are well known in which a plural number of heat exchangers that comprise these radiators are arranged on right and left in parallel with the cooling wind flow of a cooling fan to be unified to form an approximately square shaped cooling device, and said unified cooling device is stored in the cooling device storage part in the rear of an operation room (For instance, refer to the Patent Literature  2 ). By arranging such a plural number of heat exchangers in parallel on right and left, any heat exchanger can secure a good cooling efficiency and also maintenance such as cleaning etc. of each heat exchanger can be easily performed. 
     PRIOR ART LITERATURE 
     Patent Literature 
     
         
         
           
             Patent Literature 1: Utility Patent H7-27317 Gazette 
             Patent Literature 2: Japanese Unexamined Patent Application Publication No 2003-49649 Gazette 
           
         
       
    
     SUMMARY OF INVENTION 
     Challenge the Invention Attempts to Solve 
     By the way, for the aforementioned pressurized sealed type reservoir tank, to remove air in the cooling water within the circulation system of the engine cooling water, it is necessary to be positioned higher than the top part of the cooling water circulation path that comprises an engine and radiator. Because of this, as in the aforementioned patent literature 2, regarding those equipped with a cooling device unified by arranging a plural number of heat exchangers in parallel on right and left that comprises radiators, in case that the pressurized sealed type reservoir tank is tried to be adopted. The reservoir tank must be arranged higher than the top edge position of the radiator, and in order to make it higher than the top edge position of a radiator, the reservoir tank must be arranged so as to protrude upward from the cooling device. The needs are generated to make the ceiling height of the cooling device housing part higher for that portion, thus an issue exists that prevents the rearward field of vision from the operation room, and herein lies the issue to be solved by this invention. 
     Means To Solve Challenge 
     The present invention was created in order to solve these challenges in view of such situations as described above, and according to the invention in claim  1 , the arrangement structure of the cooling system in the construction equipment is characterized such that in the cooling system of the construction equipment equipped with a plural number of heat exchangers that comprise a radiator, a cooling fan that supplies cooling wind to these heat exchangers, and a pressurized sealed type reservoir tank connected in parallel with the radiator in a cooling water circulation system between the aforementioned radiator and an engine, the aforementioned plural number of heat exchangers, assuming that at least one heat exchanger other than a radiator is the upper tier heat exchanger, and that the heat exchanger that comprises a radiator other than said upper tier heat exchanger is the lower tier heat exchanger, is arranged lower than the upper tier heat exchanger, and also, the horizontal width of the entire upper tier heat exchanger arranged thus is made to be shorter than the horizontal width of the entire lower tier heat exchanger, to form the tank space laterally to the upper tier heat exchanger such that the aforementioned reservoir tank is arranged in the tank space. 
     According to the invention in claim  2 , the arrangement structure of the cooling system in the construction equipment is characterized such that in claim  1 , the upper tier heat exchanger and lower tier heat exchanger are arranged so as to be in parallel up and down with respect to the cooling wind flow, and also, the upper tier heat exchanger themselves and lower tier heat exchanger themselves are arranged so as to be in parallel up and down or right and left with respect to the flow of the cooling wind. 
     According to the invention in claim  3 , the arrangement structure of the cooling system in the construction equipment is characterized such that in claim  1  or claim  2 , the lower tier heat exchanger is a radiator and an oil cooler and the upper tier heat exchanger is an inter-cooler. 
     According to the invention in claim  4 , the arrangement structure of the cooling system in the construction equipment is characterized such that in any of the claims from claim  1  through claim  3 , the upper tier heat exchanger and lower tier heat exchanger are built into a square frame-shaped frame member, and a fan shroud that surrounds a cooling fan is connected to the same frame member, and also on the upper side corner of the frame member and fan shroud is formed a stepped concave part that partitions the tank space. 
     Effect of Invention 
     According to claim  1  of the invention, the pressurized sealed type reservoir tank can be higher than the upper end position of the radiator and be arranged not to protrude upward from the entire heat exchanger, thus can control the ceiling height of the storage room where the heat exchangers are stored. 
     According to claim  2 , a plural number of heat exchangers that comprise a radiator can be arranged such that they don&#39;t mutually overlap with respect to the cooling wind flow and secure good cooling efficiency, thus superior maintenance characteristics such as cleaning etc. 
     According to claim  3 , the present invention can be applied for the construction equipment provided with a radiator and an oil cooler and an inter-cooler, and also by making the inter-cooler to be the upper tier heat exchanger, the piping that connects the inter-cooler and engine intake air side can be shortened. 
     According to claim  4 , by the stepped concave part formed in the frame member and fan shroud, the reservoir tank can be shielded from a cooling wind and also, the upper side corner part of the frame member and fan shroud where the stepped concave part is formed_are far away from the fan rotation trajectory of the cooling fan, the impact on cooling efficiency can be made as small as possible. 
    
    
     
       BRIEF EXPLANATION OF DRAWINGS 
         FIG. 1  is a side view drawing of a hydraulic shovel with the side cover removed. 
         FIG. 2  is a main section front view drawing of a cooling system. 
         FIG. 3  is a main section back view drawing of a cooling system. 
         FIG. 4  is a block drawing showing an engine cooling water circulation system. 
         FIG. 5  is a main section front view drawing of a cooling system in the second embodiment. 
     
    
    
     FORM TO EMBODY THE INVENTION 
     The following explains the embodiments of the present invention based on drawings. In the figure,  1  is a hydraulic shovel which is an example of the construction equipment of the present invention. Said hydraulic shovel  1  is configured from each part of a lower part carrier  2 , the upper turning body  3  which is rotatably supported on said lower part carrier  2 , and work device  4  mounted on said upper part turning body  3  etc. and also, an operating room  5  is provided in the front part of the upper part turning body  3  and in the back part of said operating room  5  is provided a machine room  7  where an engine (not shown in figure) and the cooling device  6  later described etc. are stored, and furthermore, a counter weight  8  is installed in the back side of said machine room  7 . 
     The aforementioned cooling device  6  is unified by building a plural number of heat exchangers into the square framed frame member  9 , and according to the form of this embodiment, as the heat exchangers that correspond to the lower tier heat exchanger of the present invention, a radiator  10  to cool the engine cooling water, and an oil cooler  11  to cool hydraulic oil are provided, and also as the heat exchanger that corresponds to the upper side heat exchanger of the present invention, an inter-cooler  12  to cool air that is compressed by engine supercharger is provided. Then, the cooling device  6  in which these radiator  10 , oil cooler  11  and inter-cooler  12  are assembled is housed in the cooling device storage part  7   a  provided in a machine room  7 , and also it is configured to be cooled by the cooling wind that flows in by the rotation of a cooling fan  13  positioned in the rear side of a cooling device  6 . Moreover, it is configured such that the upper and front side of the cooling device storage part  7   a  is covered by a side cover free to open and close (not shown in figure), and outer air is introduced from the ventilation hole formed on said side cover, and also by opening the side cover, the maintenance etc. of cooling device  6  can be performed. Moreover, in explaining the embodiment, with respect to the cooling wind flow, the upper flow side is the front of the cooling device  6  and the lower flow side is the back side. 
     Here, the aforementioned radiator  10 , oil cooler  11 , and inter-cooler  12  are provided between the inflow side tanks  10   a,    11   a,    12   a  into which cooled fluid (in radiator  10 , engine cooling water; in oil cooler  11 , hydraulic oil; in inter-cooler  12  compressed air) flows in, and the outflow side tanks  10   b,    11   b,    12   b  from which cooled fluid flow out, and these inflow side tanks  10   a,    11   a,    12   a  and outflow side tanks  10   b,    11   b,    12   b,  and configured for general purposes to be equipped with cores  10   c,    11   c,    12   c  having a plural number of tubes and cooling fins through which cooled fluid passes. In the embodiment, regarding these radiators  10 , oil cooler  11  and inter-cooler  12 , the inflow side tanks  10   a,    11   a,    12   a  and outflow side tanks  10   b,    11   b,    12   b  are provided on right and left side of cores  10   c,    11   c    12   c,  and a side flow type in which cooled fluid flows in the right and left direction is used. Then, regarding the aforementioned radiator  10 , oil cooler  11 , and inter-cooler  12 , the radiator  10  and oil cooler  11  which are a lower tier heat exchanger, while the radiator  10  is positioned in the lower side, and oil cooler  11  is positioned in the upper side, are positioned in parallel up and down against cooling wind flow, furthermore on the upper side of these lower tier heat exchangers (in the embodiment, among the lower tier heat exchangers, the upper side of oil cooler  11  positioned on the upper side), the inter-cooler  12  which is an upper side heat exchanger is positioned up and down in parallel with respect to the lower tier heat exchangers against the cooling wind flow. In this case, the horizontal width of the radiator  10  and oil cooler  11  which are a lower tier heat exchanger and positioned parallel up and down are provided with the approximately same size and also, the horizontal width of the inter-cooler  12  which is the upper tier heat exchanger is set up shorter than the horizontal width of the radiator  10  and oil cooler  11 , thereby on the horizontal side of inter-cooler  12  is formed a tank space for reservoir tank  14  later described to be arranged. Then, in the upper side corner of frame member  9  where a radiator  10 , an oil cooler  11 , and an inter-cooler  12  are built-in is formed a stepped concave part  9   a  (frame member stepped concave part  9   a ) to partition the aforementioned tank space S. 
     Here, as the aforementioned upper tier heat exchanger, any heat exchanger other than radiator  10  can be selected, but in this embodiment, regarding construction equipment such as hydraulic shovel  1  etc., heat radiating area is small compared with radiator  10  and oil cooler  11 , and also, the inter-cooler  12  connected to engine air intake side parts (turbocharger, air intake manifold) provided on the upper side of the engine is set to be the upper tier heat exchanger. Then, as described before, tank space S ends up being formed laterally to the inter-cooler  12  which is said upper tier heat exchanger, but while said tank space S is included, the vertical and horizontal sizes of each heat exchanger (radiator  10 , oil cooler  11 , inter-cooler  12 ) is set up so that the unified cooling device  6  become approximately square shaped. 
     On the other hand,  16  is a fan shroud that surrounds the outer periphery of the aforementioned cooling fan  13 , and said fan shroud  16  is connected to the back side of the square frame shaped frame member  9  where the aforementioned radiator  10 , oil cooler  11  and inter-cooler  12  are assembled, and by said fan shroud  16 , it is designed to improve the cooling efficiency by arranging the cooling wind flow, but in the upper corner of said fan shroud  16 , while connected with the aforementioned frame member stepped concave unit  9   a,  the stepped concave unit  16   a  (shroud stepped concave unit  16   a ) is formed to partition tank space S. Then, it is configured to arrange a reservoir tank  14  via bracket  15  in the tank space S partitioned by the frame member stepped concave unit  9   a  and shroud stepped concave unit  16   a.  In this case, the part where the stepped concave units  9   a,    16   a  are formed in the frame member  9  and fan shroud  16  as shown in  FIG. 3 , is positioned far away from the fan rotation trajectory of the cooling fan  13 , with hardly any impact on cooling efficiency, in addition, the reservoir tank  14  is configured to be able to be shielded from cooling wind by the stepped concave units  9   a,    16   a  of the frame member  9  and fan shroud  16 . Moreover,  17   a  is a radiator inflow side piping to be connected to the inflow side tank  10   a  of the radiator  10 ;  17   b  is a radiator outflow side piping to be connected to the outflow side tank  10   b  of the radiator  10 ;  18   a  is an oil cooler inflow side piping to be connected to the inflow side tank  11   a  of oil cooler  11 ;  18   b  is an oil cooler outflow side piping to be connected to the outflow side tank  11   b  of oil cooler  11 ;  19   a  is an inter-cooler inflow side piping to be connected to the inflow side tank  12   a  of inter-cooler  12 ;  19   b  is an inter-cooler outflow side piping to be connected to the inflow side tank  12   a  of inter-cooler  12 . 
     Next, the engine cooling water circulation system in the embodiment is explained based on  FIG. 4 . In  FIG. 4, 10  is the aforementioned radiator, and  10   a,    10   b,    10   c  are an inflow side tank, an outflow side tank and a core of the radiator  10 ;  14  is the aforementioned reserve tank;  20  is an engine (water jacket provided in an engine);  21  is a water pump and  22  is a thermostat. 
     Then, engine cooling water circulates while the sealed and pressurized conditions prevail between the aforementioned engine  20  and radiator  10 . That is, the engine cooling water that flows out from engine  20  flows into the radiator  10  via engine exit side path  23 , thermostat  22  and radiator inflow side piping  17   a,  and after cooled by said radiator  10 , arrives at the water pump  21  via radiator outflow side piping  17   b,  and is supplied to an engine  20  via engine entrance side path  24  from said water pump  21 . Moreover, a bypath path  25  is provided between the aforementioned thermostat  22  and water pump  21 , and when engine cooling water temperature is low, the engine cooling water that flowed out from engine  20  arrives at water pump  21  via bypath  25  from thermostat  22  without going via radiator  10 , and is supplied to the engine  20 . 
     Furthermore, the reservoir tank  14  is connected in parallel with radiator  10  in the cooling water circulation system between the aforementioned radiator  10  and engine. That is, the reservoir tank  14  has a liquid phase part that stores part of engine cooling water and a gas phase above said liquid phase part internally, and is a pressurized sealed type that changes the storage volume of engine cooling water, depending on the volume change accompanied by temperature change of engine cooling water and is connected respectively to the engine exit side path  23 , the inflow side tank of radiator  10   a  via engine side vent path  26 , and radiator side vent path  27 , and also, is connected to the water pump  21  via branched path  28 . Then, part of the engine cooling water circulates via this reservoir tank  14 , and also it is designed to remove air in engine cooling water inside the reserve tank  14 . Moreover,  14   a  is a tank cap to block a water pouring mouth of the aforementioned reservoir tank  14 , and said tank cap  14   a  has a pressure adjustment function and in case the pressure inside reservoir tank  14  exceeds the pre-set upper limit pressure, said pressure is released outside of the cooling water circulation system via drain path  29 . 
     Then, it is necessary that the aforementioned reservoir tank  14  is positioned at the top location within the cooling water circulation system to remove air within the cooling water circulation system, and because of this, it is necessary that the reservoir tank  14  must be placed higher than the top edge position of the radiator  10 , but as described before, since the reservoir tank  14  is positioned in the tank space S laterally to the inter-cooler  12  which is an upper tier heat exchanger, and is configured to be positioned to be higher than the radiator  10  which is a lower tier heat exchanger. 
     In the embodiment configured as described, the cooling system in hydraulic shovel  1  is provided with a radiator  10 , an oil cooler  11  and an inter-cooler  12 , and also, is configured to be equipped with a pressurized sealed type reservoir tank  14  etc. connected in parallel with the radiator  10  in the cooling water circulation system between the cooling fan  13  that supplies cooling wind to these plural number of heat exchangers (radiator  1 , oil cooler  11  and inter-cooler  12 ), the radiator  10  and an engine. But in this thing, regarding the aforementioned plural number of heat exchangers, with the inter-cooler  12  which is a heat exchanger other than radiator  10  used as the upper tier heat exchanger, the radiator  10  and oil cooler  11  other than said upper tier heat exchanger used as a lower tier heat exchanger are arranged below the upper tier heat exchanger, and also, the horizontal width of the entire upper tier heat exchanger in said arrangement is set up shorter than the horizontal width of the entire lower tier heat exchanger, thus the tank space S is formed laterally to the upper tier heat exchanger. Then, the aforementioned reservoir tank  14  is arranged in said tank space S. 
     In the embodiment with the present invention thus executed, by arranging the reservoir tank  14  in the tank space S formed laterally to the upper tier heat exchanger positioned above the lower tier heat exchanger where radiator  10  is a lower tier heat exchanger, said reservoir tank  14  is enabled to be arranged to be higher than the top end position of radiator  10  and also not to protrude upward from the entire heat exchanger. As a result, even regarding the pressurized sealed type reservoir tank  14  connected in parallel with radiator  10  in the cooling water circulation system between the radiator  10  and engine, said reservoir tank  14  can be positioned without protruding upward from the entire heat exchanger, thus the ceiling height of the cooling device storage part  7   a  where the heat exchanger is stored can be controlled. It can avoid the ceiling height of a cooling device storage part  7   a  gets higher due to the reservoir tank  14 , and the deterioration of the rear-view field of vision from operating room  5 . 
     Also in this, the radiator  10  and oil cooler  11  that are a lower tier heat exchanger are positioned up and down in parallel with respect to the cooling wind flow that is supplied by cooling fan  13 , and the inter-cooler  12  which is the upper tier heat exchanger is positioned up and down in parallel with respect to the radiator  10  and oil cooler  11 . Also, a plural number of heat exchangers that include radiators  10  result in being positioned such that they don&#39;t mutually overlap with respect to cooling wind flow, and thus good cooling efficiency is secured and maintenance such as cleaning etc. is superior. Moreover, in the embodiment, as a plural number of heat exchangers, the radiator  10  and oil cooler  11  and inter-cooler  12  are provided that are heat exchangers generally provided for construction equipment such as hydraulic shovel  1  etc., but the inter-cooler  12  which is the upper tier heat exchanger uses those that have a smaller radiation area compared with the radiator  10  and oil cooler  11  that are generally the lower tier heat exchanger, so even though the horizontal width is shortened, the impact on cooling efficiency hardly exists, and furthermore, the inflow side  19   a  and outflow side piping  19   b  of inter-cooler  12  are connected to the engine air intake member (turbocharger, air intake manifold) provided above the engine, hence there is also an advantage in that by using the inter-cooler  12  as the upper tier heat exchanger, the inflow side  19   a  and outflow side piping  19   b  of inter-cooler  12  connected to the engine air intake side member can be shortened. 
     Furthermore, in this thing, the upper tier heat exchanger (inter-cooler  12 ) and the lower tier heat exchanger (radiator  10  and oil cooler  11 ) are unified as a cooling device  6  and built into the square framed frame member  9  but to said frame member  9  is connected the fan shroud  16  that surrounds cooling fan  13 , and also, on the upper side corner of the frame member  9  and fan shroud  16 , is formed a stepped concave units  9   a,    16   a  that partition the tank space S where a reservoir tank  14  is provided. Hence, the reservoir tank  14  can be shielded from a cooling wind by said stepped concave unit  9   a,    16   a,  and also the upper corner of the frame member  9  and fan shroud  16  where the stepped concave unit  9   a  and  16   a  are formed is far away from the fan rotation trajectory of cooling fan  13 , thus the impact on cooling efficiency can be reduced as much as possible. 
     Moreover, of course the present invention cannot be limited to the aforementioned embodiment (first embodiment), and as in the second embodiment shown in  FIG. 5 , the radiator  10  and oil cooler  11  that are the lower tier heat exchangers can be positioned on right and left in parallel with respect to cooling wind flow. Like this, even if lower tier heat exchangers themselves are positioned on right and left in parallel, the reservoir tank  14  positioned in tank space S laterally to the inter-cooler  12  that is the upper tier heat exchanger is positioned higher than the upper end part of the radiator  10  that is the lower tier heat exchanger, and plays the similar operation effect to the aforementioned first embodiment. Furthermore, in  FIG. 5 , as the radiator  10  and oil cooler  11  that are the lower tier heat exchanger, the down flow type is shown in which the inflow side tanks  10   a,    11   a  and the outflow side tanks  10   b,    11   b  are provided up and down with respect to the cores  10   c,    11   c,  but even in the second embodiment, as in the first embodiment, they can be made to be the side flow type radiator and oil cooler. By the way, in case of using a pressurized sealed type reservoir tank  14 , since the water injection mouth is provided in the reserve tank  14  but not in radiator  10 , even if a down flow type radiator  10  is used, the upper tier heat exchanger can be arranged on the upper side. 
     Furthermore, in the aforementioned first and second embodiments, the upper tier heat exchanger was set to be an intercooler, but the upper tier heat exchanger is not limited to an intercooler, as long as it is a heat exchanger other than a radiator, and for instance, an air conditioner condenser can be made to be the upper tier heat exchanger. Moreover, the upper tier heat exchanger and lower tier heat exchanger can be singular or plural, and furthermore, in addition to the upper tier heat exchanger and lower tier heat exchanger, even in case these upper tier heat exchanger, lower tier heat exchanger and other heat exchanger that overlaps with respect to cooling wind flow are provided, the present invention can be implemented. 
     Moreover, the present invention is not limited to hydraulic shovels, but of course, can be implemented for various construction equipment. 
     USDABILITY IN INDUSTRY 
     The present invention can be utilized for the cooling system of construction equipment equipped with a plural number of heat exchangers including radiators, cooling fans, reservoir tanks etc.