Concrete mixer truck

Abstract

To provide a vehicle and a concrete mixer truck which, with a simple configuration, can prevent freezing by warming water in a water tank using heat generated from the engine of the vehicle in cold seasons, and can efficiently cool the engine of the vehicle using low-temperature water in the water tank in hot seasons, etc. [Solution] A vehicle comprising an engine, engine coolant, and a passage for circulating the coolant, the passage comprising a water pump, a radiator, a heater core, and a thermostat, and a water tank mounted on the vehicle body, the water tank comprising a water inlet and a water outlet, the passage being arranged through the inner space of the water tank so as to pass through the water stored in the water tank, the passage comprising at least the three-way valve of an upstream three-way valve and a downstream one-way valve in the outer space of the water tank, the vehicle circulating the coolant that has recovered heat from the engine through heat exchange so as to pass through the heater core at least during interior heating, and when the coolant is at or above a predetermined temperature, the thermostat circulates the coolant that has recovered heat from the engine through heat exchange so as to pass through the radiator.

Description

[Technical Field]

[0001] The present invention relates to a vehicle capable of adjusting the temperature of water stored in a water tank mounted on the vehicle and the temperature of engine cooling water. [Background technology]

[0002] The water tank is mounted on a vehicle such as a concrete mixer truck (agitator truck) or a concrete pump truck, but other vehicles may also be used, and the use of the vehicle is not limited. For ease of understanding, the following description will be given using a concrete mixer truck as an example.

[0003] For example, as shown in Patent Document 1, a concrete mixer truck generally mixes aggregates such as cement and gravel with water in a predetermined ratio at a concrete plant or the like, places them into a mixing drum mounted on the concrete mixer truck, and transports the mixture to a construction site or the like while stirring the mixture to prevent the ready-mixed concrete from hardening. After the ready-mixed concrete is discharged from the mixing drum at a construction site, etc., any remaining ready-mixed concrete adhering to the inside of the drum, the feeding hopper, the discharge chute (discharge outlet), etc. must be washed immediately with water before it hardens.Concrete mixer trucks are generally equipped with water tanks so that the ready-mixed concrete can be easily washed after it is discharged, even in areas where there is no water at the site or nearby. The water in the water tank is led into the mixing drum, the feeding hopper, and the discharge chute via a connected water pump and water intake hoses and pipes, and the water is sprayed from nozzles installed in advance at predetermined positions to automatically clean the area, or the worker can clean it manually.

[0004] As shown in the drawing of Patent Document 1 in Figure 4, a concrete mixer truck 101 is equipped with a mixing drum 102 at the rear of its body, and a feeding hopper 103, a discharge chute 104, etc. are provided at the rear of the mixing drum 102. A water tank 105 for storing water for washing the mixing drum 102, feeding hopper 103, chute 104, etc. is provided on the body in front of the mixing drum 102, and a water pump 106 is provided below the water tank 105. Water from a water tank 105 is guided by a water pump 106 through a hose 107 to the rear of the vehicle to wash the mixing drum 102, the feeding hopper 103, the discharge chute 104, etc. In Fig. 4, a control box 108 incorporating a switching valve and the like (not shown) is connected to the rear end of the hose 107, and water is selectively supplied from the control box 108 to a jet nozzle (not shown) disposed in the feeding hopper 103 or the mixing drum 102, or to a cleaning hose 109 (which may have a gun attached to its tip) as a cleaning tool, for automatic or manual cleaning. At this time, there is known a technique in which the water used to wash the mixing drum 102, the feeding hopper 103, etc. is automatically collected into the mixing drum 102, and the water used to wash the discharge chute 104, etc. is temporarily stored in a bucket or the like disposed at the bottom end of the chute 104 and then poured into the drum 102.

[0005] The water tank 105 installed in the vehicle must be filled with water beforehand, and in this process, an operator must connect a specified hose or the like connected to a water source such as a tap or water tank to the water inlet of the water tank 105. One end of the water inlet is inserted into the water inlet with its cap removed, and water is poured into the water tank 105. The water tank 105 has a hollow structure with an internal space made of, for example, synthetic resin, and one longitudinal end of the bottom plane is formed with a drain outlet for removing water stored in the water tank 105, and a socket is threaded into this drain outlet. One end of a water intake hose is connected to the socket, and this end is fixed with a hose band or the like.

[0006] Furthermore, the temperature of the fresh concrete inside the mixing drum 102 can cause variations in quality, and if the average daily temperature is expected to fall below 4°C, cold weather concrete construction must be carried out, and the temperature of the fresh concrete when poured must be in the range of 5°C (10°C in some cases) to 20°C.

[0007] In a conventional concrete mixer truck such as that shown in Patent Document 1, the temperature of the water initially poured into the water tank 105 cannot be changed thereafter, so in areas where the temperature drops below freezing during cold periods such as winter, the water is heated to a certain degree before being poured in. However, while the concrete mixer truck is traveling, the temperature of the water in the water tank 105 drops, and the water freezes inside the water tank 105 and attached water intake hoses and pipes. This makes it difficult to use the water in the water tank 105 to wash the mixing drum 102, feeding hopper 103, chute 104, etc.

[0008] In particular, in cold seasons such as winter at a concrete plant or the like, when aggregates such as gravel are dropped from a predetermined conveyor or the like and fed into the mixing drum 102 from the feeding hopper 103, the gravel is heated by applying steam to it to prevent it from freezing and not falling from the conveyor or the like. In this case, when the heated gravel is mixed in the mixing drum 102 with the water or the like in a predetermined ratio, if the heated water in the water tank 105 is used for mixing, the temperature may exceed the upper limit of 20°C for cold weather concrete. Therefore, it is necessary to lower the temperature of the water to be mixed, but lowering the temperature of the water when pouring it into the water tank 105 increases the risk of the water freezing, creating a dilemma.

[0009] Therefore, we came up with the idea of ​​utilizing the heat generated by the vehicle's engine, that is, the heat from the cooling water that has absorbed heat from the vehicle's engine, to warm the water in the water tank 105 and prevent it from freezing.

[0010] Here, as an example of a conventional cooling system using cooling water for a vehicle engine, a configuration disclosed in Patent Document 2 is known. Below, an outline of the circulation structure of cooling water for a conventional vehicle engine will be described with reference to Patent Document 2. 5, as shown in the drawing of Patent Document 2, there are provided passages (which may be, for example, metal or resin pipes, hoses, etc.) connected to engine 201, radiator 203, and heater core 205. Coolant cools engine 201 by passing through coolant passages (hereinafter simply referred to as "passages") 207a, b, c, d1, d2, e, and f.

[0011] Passage 207e extends from engine 201 and is connected to passages 207d2 and 207df via a three-way valve 206. Passage 207f is connected to passage 207a via heater core 205. Passage 207a is connected to passage 207b and passage 207c extending from engine 201 via thermostat 204. A radiator 203 is provided on passage 207c. A water pump (WP) 208 is provided on passage 207b. Passage 207b is connected to passages 207d1 and 207d2. Passage 207d1 leads to a water jacket (not shown) inside engine 201. Passage 207d2 is a bypass passage that bypasses engine 201 and is connected to passages 207e and 207f via a three-way valve 206.

[0012] Engine 201 is a device that generates power by burning a mixture of supplied fuel and air. It is configured, for example, as a gasoline engine or a diesel engine. Cooling water flows into engine 201 through passage 207d1. The flowing-in cooling water passes through a water jacket inside engine 201 and then flows out through passages 207c and 207e. The water jacket is provided around a cylinder (not shown) inside engine 201, and the cylinder exchanges heat with the cooling water passing through the water jacket.

[0013] A water temperature sensor 209a for detecting the temperature of the cooling water in the engine 201 (the temperature of the cooling water in the water jacket in the engine 201) is provided near the outlet of the passage 207e of the engine 201, and supplies a corresponding detection signal to an ECU (Electronic Control Unit) not shown. Note that a configuration in which the water temperature sensor 209a is not provided is also known.

[0014] Three-way valve 206 has cooling water inlets and outlets in three directions, and each inlet and outlet has an openable / closable valve. In the example shown in Fig. 5, three-way valve 206 has cooling water inlets and outlets in the directions of passages 207d2, 207e, and 207f, and has valves f1, f2, and f3 in the inlets and outlets of passages 207d2, 207e, and 207f. Three-way valve 206 opens and closes the valves in the inlets and outlets in each direction based on control signals from the ECU. Specifically, when in the cold state, three-way valve 206 opens valves f1 and f3 in the inlets and outlets of passages 207d2 and 207f and closes valve f2 in the inlet and outlet of passage 207e, thereby circulating cooling water through a route (indicated by a solid arrow) that passes through bypass passage 207d2. In addition, when the three-way valve 206 is in the hot state, it opens the valves f2 and f3 at the inlet and outlet of each of the passages 207e and 207f, and closes the valve f1 at the inlet and outlet of the passage 207d2, thereby circulating the cooling water through a route (indicated by the wavy arrow) that passes through the engine 201 (the water jacket inside the engine 1).

[0015] The exhaust heat recovery device 202 is provided on an exhaust passage (not shown) through which exhaust gas from the engine 201 passes. Cooling water passes through the exhaust heat recovery device 202, and heat is exchanged between the cooling water and the exhaust gas, thereby recovering exhaust heat. This warms the cooling water. Note that a configuration in which the exhaust heat recovery device 2 is not provided is also known.

[0016] Water pump 208 is configured with an electric motor, and is driven to circulate the coolant through passage 7. Specifically, water pump 208 is supplied with power from a battery, and its rotation speed and other parameters are controlled by control signals supplied from the ECU. Note that instead of water pump 208, a mechanical water pump that can operate independently of the operation of engine 201 and can be controlled by the ECU may be used.

[0017] The heater core 205 is a device (heating device) that heats the air inside the vehicle cabin by the coolant that passes through it. As the coolant passes through the corrugated tube inside, it exchanges heat with the air inside the cabin. The corrugated tube is surrounded by numerous heat dissipation fins, and forced heat conduction is achieved by the wind introduced by the rotation of an electric fan (not shown). In this case, the air heated by the heater core 205 is blown into the vehicle cabin by a blower called a heater blower (not shown).

[0018] In the radiator 203, the cooling water passing through it is cooled by outside air. In this case, the cooling of the cooling water in the radiator 3 is promoted by the wind introduced by the rotation of an electric fan (not shown).

[0019] Thermostat 204 is configured as a valve that opens and closes depending on the coolant temperature. Basically, thermostat 204 opens when the coolant temperature becomes high. In this case, passages 207b and 207c are connected via thermostat 204, and the coolant passes through radiator 203. This cools the coolant and prevents overheating of engine 201. On the other hand, when the coolant temperature is relatively low, thermostat 204 closes. In this case, the coolant does not pass through radiator 203. This prevents the coolant temperature from decreasing, and therefore prevents overcooling of engine 201. When the coolant temperature is relatively low, the valve of thermostat 204 is closed by the force of a spring. However, as the temperature of engine 201 rises and the coolant temperature also rises, the valve opens little by little, allowing the coolant to circulate to radiator 203. The valve closes again when the coolant temperature reaches an appropriate level to maintain the temperature of engine 201. For example, when thermostat 204 becomes hot, the wax inside the spring melts and the material expands, pushing up the spring and opening the valve, and when engine 201 is cooled sufficiently and the temperature drops, the wax inside thermostat 204 returns to a solid and contracts, closing the valve.

[0020] A related technology involves placing a water circulation pipe connected to the water tank of a concrete mixer truck along the exhaust pipe of the vehicle's engine, and using the heat of the exhaust pipe, which has become hot due to exhaust gases, i.e., the heat generated by the engine, to heat the water in the water tank, thereby preventing the water tank of the concrete mixer truck from freezing during cold seasons (see Patent Document 3). [Prior art documents] [Patent documents]

[0021] [Patent Document 1] Japanese Utility Model Application Publication No. 6-27112 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-150266 [Patent Document 3] Japanese Utility Model Application Publication No. 58-166404 Summary of the Invention [Problem to be solved by the invention]

[0022] However, the technology disclosed in Patent Document 3 above requires the circulation pipe to be structured along the vehicle's exhaust pipe, which makes the structure complicated, making assembly and handling very inconvenient, and increasing costs. Furthermore, during hot periods such as summer, the outside temperature is high, the vehicle body heats up, and the engine heats up even more. However, the temperature of the large amount of water in the large-capacity water tank remains relatively low, and there is a problem in that it is difficult to pass the engine cooling water through a circulation pipe that passes through this large amount of low-temperature water, thereby cooling the cooling water and efficiently cooling the engine. Furthermore, in accordance with recent exhaust gas regulations and the Automobile Nox / PM Law, vehicles are fitted with exhaust gas purification devices (DPR, DPF, SCR), and therefore the structure disclosed in Patent Document 3 above has the problem of being difficult to apply to exhaust structures using recent diesel engines.

[0023] Furthermore, this invention has been developed through more than 10 years of trial and error and is a product level that can be applied to concrete mixer trucks used in public works projects, and is not merely at the idea stage.

[0024] The object of the present invention is to provide a system with a simple configuration that can use heat generated by a vehicle engine to heat the water in a water tank in cold seasons to prevent freezing, and can also use low-temperature water in the water tank to efficiently cool the vehicle engine in hot seasons. Ruko To provide a concrete mixer truck. [Means for solving the problem]

[0025] The present invention Concrete mixer truck teeth, an engine, a cooling water for the engine, and a passage for circulating the cooling water; The passage includes a water pump, a radiator, a heater core, and a thermostat. Water tank on the vehicle A mixing drum, a discharge chute, Equipped with Concrete mixer truck And, The water tank has a water inlet and a water outlet, The water in the water tank is supplied from the drain outlet to the internal space of the mixing drum and the cleaning device of the discharge chute, The passage is provided with a water tank. The aforementioned The water supply is provided through the inner space of the water tank so as to pass through the water, the passage includes at least a three-way valve among an upstream three-way valve and a downstream one-way valve in the outer space of the water tank; When the cooling water that has recovered heat from the engine through heat exchange is circulated through the heater core during indoor heating in cold weather, all of the cooling water that has passed through the heater core is supplied to the passage that passes through the inner space of the water tank, and all of the cooling water that has exchanged heat with the water stored in the water tank is supplied to the passage for cooling the engine, When the cooling water is at or above a predetermined temperature, the thermostat causes the cooling water, which has recovered the heat of the engine through the heat exchange, to circulate through the radiator.

[0026] With this simple configuration, at least during interior heating, the coolant is circulated through the heater core, and the waste heat of the coolant after it has finished warming the passenger compartment is utilized, so the efficiency of the passenger compartment heater is not reduced and the water in the water tank can be heated by the heated coolant at a predetermined temperature that passes through a passageway provided through the interior space of the water tank so as to pass through the water stored in the water tank, thereby preventing the water in the water tank from freezing. In other words, in cold seasons, the heat generated by the vehicle engine can be used to heat the water in the water tank and prevent it from freezing. In addition, during hot periods such as summer, the outside temperature rises and the engine becomes even hotter, and the coolant temperature exceeds a certain temperature at which the thermostat activates to pass the coolant through the radiator.However, the large amount of water in the large-capacity water tank remains at a relatively low temperature, and the coolant is passed through a passage that passes through this large amount of low-temperature water, cooling and lowering the temperature of the coolant, and the coolant circulating through the radiator can efficiently cool the engine. [Effects of the Invention]

[0028] According to the present invention, with a simple configuration, it is possible to use the heat generated by the engine of a vehicle to warm the water in the water tank in cold seasons to prevent freezing, and to use the low-temperature water in the water tank in hot seasons to efficiently cool the engine of the vehicle. Ruko Concrete mixer trucks can be provided. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a diagram illustrating the overall configuration of a concrete mixer truck according to an embodiment of the present invention. [Figure 2] 3 is a diagram illustrating a flow path when cooling water for an engine according to an embodiment of the present invention passes through a passage in a water tank. FIG. [Figure 3] 5 is a diagram illustrating a flow path of the engine cooling water when the cooling water does not pass through a passage in the water tank according to the embodiment of the present invention. FIG. [Figure 4] FIG. 1 is a diagram showing the configuration of a conventional concrete mixer truck. [Figure 5] FIG. 1 is a diagram showing a conventional cooling water circulation structure for a vehicle engine. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the overall configuration of a vehicle according to an embodiment of the present invention. Here, the vehicle will be described as a concrete mixer truck.

[0031] The concrete mixer truck 1 shown in Figure 1, like the one shown in Figure 4 above, is equipped with a mixing drum, a charging hopper, a discharge chute, a water tank 2 equipped with a water inlet and a drain outlet, etc., as well-known components. Since the basic components are the same, repeated explanations will be omitted here.

[0032] Also, referring to Figure 2, the concrete mixer truck 1 is equipped with an engine 3, a water pump 4, a thermostat 5, a heater core 6, a radiator 7, etc., which are related to the cooling water circulation structure of a known engine, just like the one shown in Figure 5 above. However, unlike the one shown in Figure 5, a water temperature sensor, an exhaust heat recovery device, etc. are not provided because they are not essential. Since the basic components are the same, repeated explanations will be omitted here.

[0033] In the vehicle according to this embodiment, as shown in Fig. 2, coolant passing through passage T is introduced into engine 3 by water pump 4. The introduced coolant passes through a water jacket in engine 3, passes through an external water pipe, etc., and branches into two passages via thermostat 5. Thermostat 5 basically opens when the temperature of the coolant becomes high, and the coolant passes through radiator 7, thereby cooling the coolant and preventing overheating of engine 3. On the other hand, when the temperature of the coolant is relatively low, thermostat 5 closes and the coolant passes through heater core 6.

[0034] The passage T passing through the heater core 6 is configured to extend through the interior space of the water tank 2. The passage T extends through the water stored in the water tank 2, from a predetermined hole drilled in the top surface or the like of the water tank 2 to enter the interior space of the water tank 2, bends at a predetermined depth within the water tank 2, and extends to exit through a predetermined hole drilled in the top surface or the like of the water tank 2 to exit the exterior space of the water tank 2. The contact points between the passage T and the water tank 2 where the passage T enters and exits the predetermined hole drilled in the top surface of the water tank 2 may be configured to be watertight and airtight. Needless to say, the shape of the passage T and the positions where the passage T enters and exits the water tank 2 are not particularly limited as long as the shape of the passage T passes through the water stored in the water tank 2 and produces the effects of the present invention. A three-way valve 8 provided upstream in the outer space of the water tank 2 in the middle of the passage T can switch whether the cooling water passes through the inner space of the water tank 2 or not, so that it passes through the water stored in the water tank 2. Also, a one-way valve 9 provided downstream in the outer space of the water tank 2 in the middle of the passage T can safely stop the flow of cooling water in the event of an emergency or trouble. Note that the one-way valve 9 is not essential.

[0035] The three-way valve 8 opens and closes the inlet and outlet valves for each direction under manual or electric control. Specifically, when the cooling water is to pass through the passage T in the internal space of the water tank 2, the three-way valve 8 closes the valve for the lower inlet and outlet in Fig. 2 and opens the other two valves, thereby allowing the cooling water to flow. In addition, when the cooling water is not to pass through the passage T in the internal space of the water tank 2, the three-way valve 8 closes the valve at the upper inlet / outlet in FIG. 3 and opens the other two valves, as shown in FIG. 3, to allow the cooling water to circulate. In addition, when the cooling water shown in Figure 3 is not routed through passage T in the internal space of the water tank 2, the result is the same as the cooling water circulation structure of a conventional engine, and is suitable when there is no need for the cooling water to pass through passage T in the internal space of the water tank 2, such as when the water tank 2 is not filled with water.

[0036] The passage T may be realized by a stainless steel pipe, a rubber hose, etc., and may not be a single piece, but may be formed by combining multiple parts along the way to form the passage, and there are no restrictions on the material, shape, size, etc.

[0037] Next, the operation of the concrete mixer truck 1 of this embodiment will be described.

[0038] First, during cold seasons such as winter, when temperatures drop below freezing and water freezes inside the water tank 2 and the attached water intake hoses and pipes, a heater (interior heating) is normally used to warm the interior of the vehicle, and the heat (recovered by heat exchange from the engine) of the coolant circulating through the heater core 6 (by the water pump 4) is utilized. That is, during cold seasons, the heat generated by the engine 3 of the concrete mixer truck 1 is used to heat the water in the water tank 2, preventing it from freezing. In this case, the waste heat of the coolant that has already warmed the interior of the vehicle is utilized, so the water in the water tank 2 can be heated without reducing the efficiency of the interior heater. This prevents the water in the water tank 2 from freezing, and the relatively high temperature of the water in the water tank 2 also makes it possible to melt and wash away frozen concrete adhering to the discharge chute (discharge outlet).

[0039] On the other hand, during hot periods such as summer, when the outside temperature is high and the vehicle body is heated by sunlight, the engine 3 becomes even hotter. However, in situations where the temperature of the large amount of water in the large-capacity water tank 2 is kept relatively low, passing the coolant through a passageway in this large amount of low-temperature water cools the coolant more than before, lowering the temperature of the coolant circulating via the radiator 7 and thereby cooling the engine 3 more efficiently. That is, during hot periods, the coolant is likely to exceed a predetermined temperature, and the thermostat 5 causes the coolant that recovers heat from the engine 3 by heat exchange to circulate through the radiator 7. However, there are cases where the coolant is not sufficiently cooled by the radiator 7 alone. In such cases, the efficiency of cooling the engine 3 decreases, posing a risk of problems. However, cooling the coolant using low-temperature water in the cold water tank 2 is an effective countermeasure. Furthermore, draining the warmed water from the water tank 2 and replacing it with fresh, cold water can further help cool the engine 3 more efficiently. It should be noted that even during periods other than the hot season such as summer, the above-described remarkable effects can be similarly achieved in environments and situations where the effect of efficiently cooling the engine 3 can be expected.

[0040] In this embodiment, as shown in FIG. 2, the cooling water is circulated so as to pass through the heater core 6 even when the heater (room heating) is not in use. However, when the heater (indoor heating) is not in use, the bypass of passage T may be positioned, configured, or controlled in a way that allows the coolant to circulate through engine 3 and radiator 7 without passing through heater core 6 (or the circulation of the coolant may be stopped when the coolant is below a predetermined temperature and does not pass through radiator 7 due to thermostat 5). In other words, various configurations, including known technologies, may be applied to the coolant circulation structure upstream of water tank 2, as long as they achieve the effects of utilizing heater core 6 and radiator 7 of the present invention.

[0041] According to the present embodiment, the passage extending by the cooling water bypass can be installed in a vehicle compactly with a simple configuration, and is compatible with recent diesel engines (with exhaust gas purification devices) as well as conventional diesel engines. In addition, since the temperature of the water in the water tank 2 becomes warmer, the water is supplied from the drain outlet of the water tank 2 to the internal space of the mixing drum and the cleaning tool of the discharge chute, which has the effect of making it easier to remove concrete and dirt that has adhered to the vehicle when cleaning using that water.

[0042] Although the above description is based on the assumption that a concrete mixer truck is used as an example of a vehicle, the present invention is not limited to concrete mixer trucks and can be similarly applied to other vehicles equipped with a water tank. For example, by raising the temperature of the water in the water tank, you can use that water to take a warm shower when the water supply is cut off during cold seasons or after a disaster such as an earthquake.

[0043] Finally, the present embodiment described above is a preferred embodiment of the present invention, and various modifications can be made to the configuration, arrangement, shape, size, number, ratio, etc. within the scope of the gist of the present invention. [Explanation of symbols]

[0044] T aisle 1. Concrete mixer truck 2 water tanks 3 Engine 4. Water pump 5. Thermostat 6. Heater Core 7. Radiator 8 Three-way valve 9 One-way valve

Claims

[Claim 1] an engine, a cooling water for the engine, and a passage for circulating the cooling water; The passage includes a water pump, a radiator, a heater core, and a thermostat. A concrete mixer truck equipped with a water tank, a mixing drum, and a discharge chute on a vehicle body, The water tank has a water inlet and a water outlet, The water in the water tank is supplied from the drain outlet to the internal space of the mixing drum and the cleaning device of the discharge chute, the passage is provided through an inner space of the water tank so as to pass through the water stored in the water tank, the passage includes at least a three-way valve among an upstream three-way valve and a downstream one-way valve in the outer space of the water tank; When the cooling water that has recovered heat from the engine through heat exchange is circulated through the heater core during indoor heating in cold weather, all of the cooling water that has passed through the heater core is supplied to the passage that passes through the inner space of the water tank, and all of the cooling water that has exchanged heat with the water stored in the water tank is supplied to the passage for cooling the engine, When the cooling water is at a predetermined temperature or higher, the thermostat circulates the cooling water that has recovered the heat of the engine through the heat exchange so that the cooling water passes through the radiator. Concrete mixer truck.

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