JP2009274462A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner not requiring an electric heater of a large capacity, in heating using hot water heated by the electric heater. <P>SOLUTION: An oil cooler 15 for drain oil which cools drain oil and heats water by heat absorbed from the drain oil is connected to a drain port from which internally leaked oil of main pumps 2, 3 is discharged outside as drain oil. A heating tank 18T with an in-like type electric heater 18 built therein communicates with and is connected to a water passing pipe of the oil cooler 15 for drain oil, and the heating tank 18T communicates with and is connected to a suction port of a hot water pump 19. A discharge port of the hot water pump 19 communicates with and is connected to an inlet port of a three-way valve type solenoid valve 21. One outlet port of the solenoid valve 21 is circulation-connected to the water passing pipe of the oil cooler 15 for drain oil, and the other outlet port of the solenoid valve 21 is similarly circulation-connected to the water passing pipe of the oil cooler 15 for drain oil via a heater core 22 as a heat radiator for heating. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air conditioner characterized by a heating function.

  Since ordinary machines such as automobiles and hydraulic excavators are equipped with an engine, the waste heat from this engine is used as a heat source for heating, and hot water is supplied from the water-cooled cooling device (radiator) such as a radiator to the air conditioner body. Is sending. In this case, most of the waste heat of the engine is radiated from the cooling device to the atmosphere.

On the other hand, an electric excavator that operates by driving a hydraulic pump with an electric motor, unlike a hydraulic excavator that drives a hydraulic pump with an engine, does not have a water-cooled cooling device, and therefore cannot send hot water to the air conditioner body. . Therefore, hot water is boiled with an electric heater and supplied to the air conditioner body of the work machine (see, for example, Patent Document 1).
JP 2002-61230 A (Page 4-5, FIG. 1)

  Thus, since the conventional electric hydraulic excavator boils hot water with an electric heater, a large-capacity electric heater is required.

  This invention is made | formed in view of such a point, and it aims at providing the air conditioner which does not require a high capacity | capacitance electric heater in the heating using the hot water heated by the electric heater.

  According to the first aspect of the present invention, an oil cooler for drain oil that cools high-temperature drain oil leaked from hydraulic equipment with water and preheats the water, and water preheated by the oil cooler for drain oil are electrically It is an air conditioner provided with a heating tank heated by a heater, and an oil cooler for these drain oils and a heating radiator that radiates hot water heated in the heating tank.

  According to a second aspect of the present invention, there is provided an air conditioner according to the first aspect, wherein an electromagnetic valve provided in a path for supplying hot water to the radiator and the electromagnetic valve are electrically connected until the water temperature reaches a specified temperature. A controller that keeps the hot water heated by the heater circulating in the oil cooler for drain oil and switches the hot water heated by the electric heater to a path that leads to the radiator when the water temperature exceeds a specified temperature. is there.

  The invention described in claim 3 is a main pump in which the hydraulic equipment in the air conditioner according to claim 1 or 2 is mounted on a work machine, and the radiator is installed in a cab mounted on the work machine. It is a thing.

  According to the invention described in claim 1, the hot water preheated by the oil cooler for drain oil using the high-temperature drain oil of the hydraulic equipment is heated by the electric heater of the heating tank, so that it becomes a radiator for heating. Since hot water is supplied, a conventional large-capacity electric heater is not required, heating power can be reduced, and energy saving can be achieved. Also, drain oil leaking from gaps such as sliding parts of hydraulic equipment has a higher temperature rise speed and higher temperature than return oil from the hydraulic actuator and hydraulic oil in the tank. Can do.

  According to the second aspect of the present invention, the controller controls the solenoid valve so that the hot water heated by the electric heater is circulated to the oil cooler for the drain oil until the water temperature reaches the specified temperature. When the water temperature exceeds the specified temperature, the solenoid valve is switched to the path that guides the hot water heated by the electric heater to the radiator.Before switching the solenoid valve, the water temperature can be heated to the specified temperature in a short time, and the solenoid valve After switching, hot water whose temperature is appropriately controlled can be supplied to the radiator.

  According to the invention described in claim 3, since the hydraulic device is the main pump mounted on the work machine and the radiator is installed in the cab mounted on the work machine, the hydraulic machine generates the main pump. Heat can be effectively used for heating in the cab.

  Hereinafter, the present invention will be described in detail with reference to one embodiment shown in FIG. 1 and FIG.

  FIG. 1 shows an overall system configuration, and an embodiment of the system configuration diagram of the present invention shown in FIG. 1 shows an electric motor 1 mounted on a hydraulic excavator as a work machine. These drive shafts are connected to and driven by main pumps 2 and 3 as hydraulic equipment for driving various hydraulic actuators of the excavator. The electric motor 1 and the main pumps 2 and 3 are mounted on an upper swing body of a hydraulic excavator.

  The air conditioner mounted on the hydraulic excavator includes a compressor 4 that compresses a refrigerant, and a rotation transmission mechanism 6 is provided between the motor 5 that drives the compressor 4.

  The rotation transmission mechanism 6 is configured such that a belt 6c is wound between a pulley 6a provided on the rotating shaft of the electric motor 5 and a pulley 6b provided on the rotating shaft of the compressor 4, and the rotation of the compressor 4 is rotated. The shaft is provided with an electromagnetic clutch 7 that turns the compressor 4 on and off.

  The discharge side of the compressor 4 is connected in communication with a condenser (condenser) 10 for cooling and condensing the refrigerant by a fan 9 driven by an electric motor 8. The cooler 11 is installed adjacently.

  The condenser 10 is connected in communication with a receiver dryer 12, and this receiver dryer 12 is connected in communication with an evaporator (evaporator) 13. The evaporator 13 is circulated and connected to the compressor 4 to constitute a cooling device. The return oil cooling oil cooler 11 is a heat exchanger that cools the hydraulic oil in the hydraulic circuit 14 that operates various hydraulic actuators of the excavator.

  An oil cooler 15 for drain oil as a heat exchanger that cools the drain oil and warms the water with the heat absorbed from the drain oil is provided at the drain port that discharges the internal leakage oil of the main pumps 2 and 3 to the outside. The drain oil cooler 15 is connected to a tank 17 via a filter 16.

  A heating tank 18T incorporating an in-line type electric heater 18 is connected to the water pipe portion of the drain oil cooler 15, and the heating tank 18T is connected to the suction port of the hot water pump 19. . The hot water pump 19 is driven by the electric motor 20.

  The discharge port of the hot water pump 19 is connected to an inlet port of a solenoid valve 21 of a three-way switching valve type, and one outlet port of the solenoid valve 21 is circulated and connected to a water pipe portion of the oil cooler 15 for drain oil. Further, the other outlet port of the electromagnetic valve 21 is circulated and connected to the water pipe portion of the drain oil oil cooler 15 through a heater core 22 as a radiator for heating provided in the evaporator 13.

  The electric heater 18 of the heating tank 18T, the electric motor 20 of the hot water pump 19, and the solenoid of the electromagnetic valve 21 are connected to the output unit of the controller 23. The signal input section of the controller 23 includes a temperature setter 24 for setting the temperature in the cab of the hydraulic excavator, a water temperature sensor 25 for detecting the water temperature in the heating tank 18T, and an air conditioner controller 26 for controlling the air conditioner. Each is connected.

  The cooling evaporator 13 and the heating heater core 22 are built in an air conditioner main body 27 installed inside a cab mounted on an upper swing body of a hydraulic excavator.

  FIG. 2 is a control block diagram showing the configuration of the controller 23, and this controller 23 is operated by a signal from the air conditioner controller 26.

  In FIG. 2, the temperature setter 24 and the water temperature sensor 25 are connected to a subtracter 28 that compares the signal of the temperature setter 24 and the signal of the water temperature sensor 25, and this subtractor 28 is connected to the heater controller 29. The heater controller 29 is connected to the electric heater 18 and controls on / off of the electric heater 18 by temperature deviation.

  Further, the water temperature sensor 25 is connected to a valve controller 30, and the valve controller 30 performs on / off control of the electromagnetic valve 21 based on the temperature detected by the water temperature sensor 25.

  Next, the function and effect of the embodiment shown in FIGS. 1 and 2 will be described with reference to the flowchart shown in FIG. The cooling function of the evaporator 13 and the like shown in FIG. 1 is the same as that of the conventional air conditioner, so the description thereof will be omitted and only the heating function will be described.

(Step S1)
In FIG. 1, it is determined whether or not there is an activation signal from the air conditioner controller 26.

(Step S2)
When there is an activation signal from the air conditioner controller 26, the controller 23 is activated and the hot water pump 19 is driven by the electric motor 20.

(Step S3)
When the hydraulic excavator is operated, the drain oil of the main pumps 2 and 3 flows to the tank 17 through the drain oil cooler 15 and the filter 16. At this time, the drain oil leaking from the gaps such as the sliding parts of the main pumps 2 and 3 is hotter than the return oil of the other hydraulic circuit 14 and the hydraulic oil in the tank 17, so When water is circulated by driving the pump 19, the water is warmed by the drain oil cooler 15.

(Step S4)
In FIG. 2, the set temperature signal set by the temperature setter 24 and the detected water temperature signal of the heating tank 18T detected by the water temperature sensor 25 are compared by the subtractor 28, and the temperature deviation is within a certain range. It is judged by the heater controller 29 whether or not it has been settled.

(Step S5)
When the temperature deviation between the set temperature and the detected water temperature does not fall within a certain range (when the detected water temperature is lower than the set temperature by a certain value or more), the heater controller 29 controls the electric heater 18 to be turned on to warm the water.

(Step S6)
When the detected water temperature rises and the temperature deviation between the set temperature and the detected water temperature falls within a certain range, the heater controller 29 controls the electric heater 18 to be turned off.

(Step S7)
The detected water temperature signal of the water temperature sensor 25 is also input to the valve controller 30 to determine whether or not the water temperature in the heating tank 18T has reached a specified temperature.

(Step S8)
Until the water temperature in the heating tank 18T reaches the specified temperature, the valve controller 30 controls the electromagnetic valve 21 to the off position shown in FIG. 1, and the water discharged from the hot water pump 19 is drained from the electromagnetic valve 21. The water is supplied to the oil cooler 15 for oil, circulated to the hot water pump 19 through the heating tank 18T, and the water is heated by the heat transferred from the high-temperature drain oil to the circulating water in the water conduit by the oil cooler 15 for drain oil. To raise. At this time, the heater controller 29 also performs on / off control of the electric heater 18 at the same time.

(Step S9)
When the detected water temperature of the heating tank 18T reaches a specified temperature, the valve controller 30 controls the electromagnetic valve 21 to be turned on, and flows the hot water to the heater core 22 of the air conditioner main body 27 installed in the cab of the hydraulic excavator, Hot water heat is used to heat the cab.

  Next, the effect of the illustrated embodiment will be described. The hot water preliminarily heated by the drain oil cooler 15 using the high-temperature drain oil leaked from the main pumps 2 and 3 of the hydraulic excavator is converted into the heating tank 18T. Heating by the electric heater 18 and supplying hot water to the radiator for heating eliminates the need for a large-capacity electric heater as in the past, reduces the power consumed for heating and saves energy .

  In addition, the drain oil leaking from the gaps such as the sliding parts of the main pumps 2 and 3 has a higher temperature rising speed and higher temperature than the return oil from the hydraulic actuator and the hydraulic oil in the tank 17. The water can be warmed immediately.

  Furthermore, the controller 23 controls the electromagnetic valve 21 to maintain the state in which the hot water heated by the electric heater 18 is circulated from the hot water pump 19 to the drain oil cooler 15 until the water temperature reaches a specified temperature. When the water temperature exceeds the specified temperature, the electromagnetic valve 21 is switched to a path that guides the hot water discharged from the hot water pump 19 to the heater core 22, so that the water temperature can be heated to the specified temperature in a short time before switching the electromagnetic valve 21, After switching the solenoid valve 21, hot water whose temperature is appropriately controlled can be supplied to the heater core 22.

  The hydraulic equipment is the main pumps 2 and 3 mounted on the upper swing body of the excavator, and the heater core 22 is installed in the cab mounted on the hydraulic excavator. Heat can be effectively used for heating in the cab.

  As described above, the effect is exhibited by the heating function of the air conditioner mounted on an electric hydraulic excavator or the like that does not include a water-cooled cooling device (radiator) as a cooling device for the prime mover.

  In addition to the main pumps 2 and 3, the hydraulic equipment may be a relief valve in the hydraulic circuit 14. For example, drain oil leaked from a relief valve such as a pilot circuit passes through the drain oil cooler 15. By collecting in the tank 17, the drain oil may be cooled with water from the hot water pump 19 and the water may be preheated.

  The present invention is an air conditioner useful as a heating device mounted on a work machine or the like.

1 is a system configuration diagram showing an embodiment of an air conditioner according to the present invention. It is a control block diagram which shows the structure of the controller of an air conditioner same as the above. It is a flowchart which shows the control flow of an air conditioner same as the above.

Explanation of symbols

2,3 Main pump as hydraulic equipment
15 Oil cooler for drain oil
18 Electric heater
18T heating tank
21 Solenoid valve
22 Heater core as a radiator
23 Controller

Claims (3)

An oil cooler for drain oil that cools high-temperature drain oil leaked from hydraulic equipment with water and preheats the water;
A heating tank for heating water preheated by the drain oil cooler with an electric heater;
An air conditioner comprising: an oil cooler for the drain oil and a radiator for heating that radiates hot water heated in the heating tank. A solenoid valve provided in the path for supplying hot water to the radiator;
This solenoid valve is maintained in a state where the hot water heated by the electric heater is circulated to the oil cooler for the drain oil until the water temperature reaches the specified temperature, and when the water temperature exceeds the specified temperature, the hot water heated by the electric heater is dissipated. The air conditioner according to claim 1, further comprising: a controller that switches to a path that leads to the air conditioner. The hydraulic equipment is the main pump mounted on the work machine,
The air conditioner according to claim 1 or 2, wherein the radiator is installed in a cab mounted on a work machine.

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