Heating device for a working machine, and a method for controlling the heating device for a working machine

Abstract

The heating device (3) of the work machine is equipped with a heating circuit (41), an electric component cooling circuit (42), a first valve (43), and a controller (47). The heating circuit (41) has a first flow path (54) through which water used for heating flows, an electric heater (51) that heats the water in the first flow path (54), and a first temperature sensor (56) that detects the temperature of the water in the first flow path (54). The electric component cooling circuit (42) has a second flow path (63) through which water used to cool the electric component (62) flows, and a second temperature sensor (66) that detects the temperature of the water in the second flow path (63). The first valve (43) is positioned between the heating circuit (41) and the electric component cooling circuit (42) and connects the electric component cooling circuit (42) to the heating circuit (41) or separates the electric component cooling circuit (42) from the heating circuit (41). The controller (47) operates the first valve (43) based on the detection value Tc of the first temperature sensor (56) and the detection value Te of the second temperature sensor (66).

Description

Technology Field

[0001] The present invention relates to a heating device for a working machine and a method for controlling the heating device for a working machine. Background Technology

[0002] Recently, work machines equipped with a battery-driven electric motor as a power source are being used. In such electric work machines, hot water for air conditioning is heated by an electric heater (see, for example, Patent Document 1). In the heating device of the work machine shown in Patent Document 1, an electric heater is installed in a radiator, and the water in the radiator is heated by the electric heater and supplied to a heat exchanger of a heater unit. Prior art literature

[0003] Japanese Patent Publication No. 2003-267037 The problem to be solved

[0004] However, in order to heat the water cooled to the ambient temperature by the electric heater, the power required for the electric heater increased, and the operating time for performing the work became shorter.

[0005] The present disclosure aims to provide a heating device for a work machine capable of reducing the power used for heating, and a method for controlling the heating device for a work machine. means of solving the problem

[0006] A heating device of a work machine according to the first aspect of the present disclosure comprises a heating circuit, an electrical component cooling circuit, a first valve, and a controller. The heating circuit has a first flow path through which a refrigerant used for heating flows, an electric heater that heats the refrigerant in the first flow path, and a first temperature sensor that detects the temperature of the refrigerant in the first flow path. The electrical component cooling circuit has a second flow path through which a refrigerant used to cool electrical components flows, and a second temperature sensor that detects the temperature of the refrigerant in the second flow path. The first valve is disposed between the heating circuit and the electrical component cooling circuit and connects the electrical component cooling circuit to the heating circuit or disconnects the electrical component cooling circuit from the heating circuit. The controller operates the first valve based on the detection value of the first temperature sensor and the detection value of the second temperature sensor.

[0007] A method for controlling a heating device of a work machine according to a second aspect of the present disclosure comprises a first temperature acquisition step, a second temperature acquisition step, and a flow path control step. The first temperature acquisition step acquires the temperature of a refrigerant in a heating circuit comprising a first flow path through which a refrigerant used for heating flows and a heater that heats the refrigerant in the first flow path. The second temperature detection step acquires the temperature of a refrigerant in an electrical component cooling circuit comprising a second flow path through which a refrigerant used for cooling an electrical component flows. The flow path control step combines the electrical component cooling circuit with the heating circuit or separates the electrical component cooling circuit from the heating circuit based on the temperature acquired in the first temperature acquisition step and the temperature acquired in the second temperature acquisition step. Effects of the invention

[0008] According to an aspect of the present disclosure, a heating device for a work machine capable of reducing the power used for heating, and a method for controlling the heating device for a work machine can be provided. Brief explanation of the drawing

[0009] FIG. 1 is a side view showing an electric shovel according to an embodiment of the present disclosure. FIG. 2 is a drawing showing the internal configuration of the cap of an electric shovel and the configuration of a heating device according to an embodiment of the present disclosure. FIG. 3 is a flowchart for explaining the control of a heating circuit of a heating device in an electric shovel according to an embodiment of the present disclosure. FIG. 4 is a flowchart illustrating the control of an electric component cooling circuit, a first valve, an operating fluid cooling circuit, and a heat exchange switching section of a heating device in an electric shovel according to an embodiment of the present disclosure. Specific details for implementing the invention

[0010] An electric shovel as an example of a working machine according to the present disclosure will be described below with reference to the drawings.

[0011] <Composition>

[0012] (Overview of electric shovel (1))

[0013] FIG. 1 is a side view showing the configuration of the electric shovel (1) of the present embodiment.

[0014] An electric shovel (1) (an example of a work machine) is operated by electric power. The power is stored in a battery (62b) (see FIG. 2) described later. The electric shovel (1) has a shovel body (2) and a heating device (3) (see FIG. 2). The heating device (3) heats the inside of the cap (14) of the shovel body (2).

[0015] The shovel body (2) has a driving body (11) and a turning body (12). The driving body (11) has a pair of driving devices (11a) (only the left one is shown in FIG. 1). Each driving device (11a) has a crawler (11b). The electric shovel (1) is driven by power from a battery (62b) (see FIG. 2) to be described later, which causes the driving motor to rotate and drive the crawler (11b).

[0016] The pivot body (12) is positioned above the vehicle body (11). The pivot body (12) is configured to pivot relative to the vehicle body (11) around an axis along the vertical direction. The pivot body (12) has a pivot frame (13), a cab (14), and a work device (15). The pivot frame (13) is a frame positioned above the vehicle body (11) and pivotable relative to the vehicle body (11).

[0017] The work device (15) is mounted at the front center of the slewing frame (13). As shown in FIG. 1, the work device (15) has a boom (21), an arm (22), and a bucket (23). The base end of the boom (21) is rotatably connected to the slewing frame (13). Additionally, the front end of the boom (21) is rotatably connected to the base end of the arm (22). The front end of the arm (22) is rotatably connected to the bucket (23). The bucket (23) is mounted on the arm (22) so that its opening can face the direction (rear) of the slewing body (12).

[0018] Hydraulic cylinders (24–26) (boom cylinder (24), arm cylinder (25), and bucket cylinder (26)) are arranged to correspond to each of the boom (21), arm (22), and bucket (23). The boom cylinder (24) is arranged on both the left and right sides of the boom (21). The working device (15) is driven by the operation of these hydraulic cylinders (24–26) (an example of a hydraulic actuator). Thus, work such as excavation is performed.

[0019] The rear side of the cap (14) of the swivel body (12) houses the electrical components (62) and hydraulic pump (71) described later.

[0020] The cab (14) is installed at the left-side position of the entire swivel frame (13). FIG. 2 is a schematic diagram showing the configuration of the heating device (3) and the interior of the cab (14). The cab (14) has a driver's seat (27), an air conditioning duct (28), an outside air filter (29), an inside air filter (30), a fan (31), and an evaporator (32).

[0021] An operator is seated in the driver's seat (27). Although not shown, the cab (14) is equipped with an operating member for operating the driving device (11a) and the work device (15), and an input device for providing input regarding the operation. An air conditioning duct (28) is installed in the cab (14). The air conditioning duct (28) supplies warmth to the operator seated in the driver's seat (27). The air conditioning duct (28) guides the air outside and inside the cab (14) upwards toward the driver's seat (27).

[0022] An outside air filter (29) is positioned at the opening of an air conditioning duct (28) that receives air from the outside of the cap (14). The outside air filter (29) removes dust and other debris from the air received into the air conditioning duct (28). An inside air filter (30) is positioned at the opening of an air conditioning duct (28) that receives air from the inside of the cap (14). The inside air filter (30) removes dust and other debris from the air received into the air conditioning duct (28).

[0023] A fan (31) is positioned inside the air conditioning duct (28) and inside the outside air filter (29). The fan (31) draws air into the air conditioning duct (28) through the outside air filter (29) and the inside air filter (30). An evaporator (32) is positioned in the air conditioning duct (28). The evaporator (32) reduces moisture by cooling the air drawn in from the outside air filter (29) and the inside air filter (30).

[0024] (Heating device (3))

[0025] The heating device (3) heats the cap (14). The heating device (3) has a heating circuit (41), an electrical component cooling circuit (42), a first valve (43), an operating fluid cooling circuit (44), a heat exchange switching unit (45), a heating switch (46), and a controller (47).

[0026] The heating circuit (41) heats the inside of the cap (14). The electrical component cooling circuit (42) cools the electrical component (62). The first valve (43) connects the electrical component cooling circuit (42) to the heating circuit (41) or separates the electrical component cooling circuit (42) from the heating circuit (41). The hydraulic fluid cooling circuit (44) cools the hydraulic fluid. The heat exchange switching unit (45) switches between a state where heat exchange is possible between the hydraulic fluid cooling circuit (44) and the electrical component cooling circuit (42) and a state where heat exchange between the hydraulic fluid cooling circuit (44) and the electrical component cooling circuit (42) is stopped. The controller (47) controls the heating device (3).

[0027] (Heating circuit (41))

[0028] The heating circuit (41) has an electric heater (51), a first water tank (52), a heater core (53), a first flow path (54), a first water pump (55), and a first temperature sensor (56).

[0029] The electric heater (51) heats the water (refrigerant) used for heating. The electric heater (51) is, for example, an electric heater.

[0030] The electric heater (51) is placed inside the first water tank (52). The water inside the first water tank (52) is heated by the electric heater (51). The electric heater (51) is turned on or off by an on signal and an off signal from the controller (47).

[0031] The heater core (53) is positioned inside the cap (14) as shown in FIG. 2. A water passage for heating is installed in the heater core (53). The heater core (53) heats the air that is drawn in by the fan (31) through the outside air filter (29) and the inside air filter (30) and passes through the evaporator (32) by exchanging heat with the water. Additionally, an air mix damper (57) is positioned in the heater core (53) to adjust the amount of air passing through the heater core (53).

[0032] The first flow path (54) is a flow path through which water heated by the electric heater (51) passes. The first flow path (54) connects the first water tank (52) and the heater core (53) to circulate water.

[0033] The first water pump (55) is positioned in the first water path (54). The first water pump (55) is positioned between the heater core (53) and the first water tank (52). The first water pump (55) circulates water between the first water tank (52) and the heater core (53). Based on the flow of water by the first water pump (55), the first water pump (55) is positioned in the part of the first water path (54) that is downstream of the first water tank (52) and upstream of the heater core (53).

[0034] The first temperature sensor (56) detects the temperature Tc of the water in the first flow path (54). The first temperature sensor (56) detects the temperature of the water in the part of the first flow path (54) that is downstream of the first water pump (55) and upstream of the heater core (53). The first temperature sensor (56) detects the temperature of the water that is heated by the electric heater (51) and before it enters the heater core (53). The first temperature sensor (56) transmits information on the detected water temperature Tc to the controller (47).

[0035] (Electric component cooling circuit (42))

[0036] The electrical component cooling circuit (42) has a radiator (61), an electrical component (62), a second flow path (63), a second water tank (64), a second water pump (65), and a second temperature sensor (66). In the electrical component cooling circuit (42), water is used as an example of a refrigerant.

[0037] The radiator (61) cools the water that cools the electrical components (62). The radiator (61) cools the coolant by performing heat exchange between the outside air and the coolant, for example.

[0038] The electrical components (62) include a main motor (62a) (electric motor), a battery (62b) (capacitor), a DC-DC converter (62c), and an inverter (62d). The main motor (62a) drives a hydraulic pump (71) described later. The battery (62b) stores power to drive the main motor (62a). The DC-DC converter (62c) boosts the voltage supplied from the battery (62b) to the main motor (62a). The inverter (62d) controls the main motor (62a).

[0039] The second flow path (63) is a flow path through which water passes to cool the electrical component (62). The second flow path (63) is connected to the second water tank (64). Based on the direction in which water flows through the second flow path (63) by driving the second water pump (65), the second water tank (64) is positioned upstream of the electrical component (62) and downstream of the radiator (61). Water is stored in the second water tank (64). The second flow path (63) circulates water so that water discharged from the second water tank (64) returns to the second water tank (64) around the electrical component (62) and through the radiator (61). And, the second Euro (63) may be configured to branch off from the upstream side of the electric component (62) and join downstream of the electric component (62) so as to pass around the main motor (62a), battery (62b), DC-DC converter (62c), and inverter (62d).

[0040] The second water pump (65) is positioned in the second flow path (63). The second water pump (65) supplies water from the second water tank (64) to the second flow path (63) and circulates water to return water to the second water tank (64). The second water pump (65) is positioned in the part of the second flow path (63) downstream of the second water tank (64) and upstream of the electrical component (62).

[0041] The second temperature sensor (66) detects the temperature Te of the water in the second flow path (63). For example, the second temperature sensor (66) detects the temperature of the water in the part of the second flow path (63) that is downstream of the electrical component (62) and upstream of the radiator (61). The second temperature sensor (66) detects the temperature of the water that has passed around the electrical component (62). The second temperature sensor (66) transmits information on the detected water temperature Te to the controller (47).

[0042] (First valve (43))

[0043] The first valve (43) is positioned between the heating circuit (41) and the electric component cooling circuit (42). The first valve (43) is, for example, an electromagnetic valve and, upon a command signal from the controller (47), connects the electric component cooling circuit (42) to the heating circuit (41) or separates the electric component cooling circuit (42) from the heating circuit (41).

[0044] The first valve (43) is positioned in the heating circuit (41) in the part upstream of the first water tank (52) in the first flow path (54) and also downstream of the heater core (53). The first valve (43) is positioned in the electrical component cooling circuit (42) in the part upstream of the radiator (61) in the second flow path (63) and also downstream of the second temperature sensor (66).

[0045] The first valve (43) has four ports P1 to P4. The first valve (43) has a valve body (not shown). The valve body can be located at either a joining position T1 or a non-joining position T2.

[0046] The first port P1 and the second port P2 are connected to the first flow path (54). The first port P1 is connected to the downstream end of the heater core (53) in the first flow path (54). The second port P2 is connected to the upstream end of the first water tank (52) in the first flow path (54).

[0047] The third port P3 and the fourth port P4 are connected to the second flow path (63). The third port P3 is connected to the downstream end of the second temperature sensor (66) in the second flow path (63). The fourth port P4 is connected to the upstream end of the radiator (61) in the second flow path (63).

[0048] The first valve (43) connects the first port P1 and the second port P2 and connects the third port P3 and the fourth port P4 when the valve body is moved to the non-converging position T2. ​​As a result, the heating circuit (41) and the electrical component cooling circuit (42) are separated without being joined.

[0049] The first valve (43) connects the first port P1 and the fourth port P4 and connects the second port P2 and the third port P3 when the valve body is moved to the joining position T1. In this way, the electric component cooling circuit (42) is joined to the heating circuit (41). Specifically, the first flow path (54) and the second flow path (63) are connected in series. Specifically, water from the first water tank (52) in which the electric heater (51) is installed flows in the order of the first water pump (55), the first temperature sensor (56), the heater core (53), port P1, port P4, the radiator (61), the second water tank (64), the second water pump (65), the electric component (62), the second temperature sensor (66), port P3, and port P2, and is returned to the first water tank (52). When the heating circuit (41) and the electric component cooling circuit (42) are joined, water circulates through the first path (54) and the second path (63) in this manner.

[0050] (Operating fluid cooling circuit (44))

[0051] The hydraulic fluid cooling circuit (44) has a hydraulic pump (71), an oil cooler (72), a third fluid path (73), a hydraulic fluid tank (74), and a third temperature sensor (75).

[0052] The hydraulic pump (71) supplies hydraulic fluid to the aforementioned hydraulic cylinders (24-26). The hydraulic fluid tank (74) stores the hydraulic fluid. The hydraulic pump (71) supplies the hydraulic fluid from the hydraulic fluid tank (74) to the hydraulic cylinders (24-26). The oil cooler (72) cools the hydraulic fluid. The oil cooler (72) cools the hydraulic fluid by, for example, performing heat exchange between the outside air and the hydraulic fluid.

[0053] The third path (73) connects the hydraulic pump (71), the hydraulic cylinders (24-26), the oil cooler (72), and the hydraulic fluid tank (74). Based on the direction in which the hydraulic fluid flows by the hydraulic pump (71), the hydraulic fluid tank (74) is positioned upstream of the hydraulic pump (71) and downstream of the oil cooler (72). When the hydraulic pump (71) is driven, the hydraulic fluid supplied from the hydraulic fluid tank (74) to the third path (73) passes through the hydraulic cylinders (24-26), is cooled by the oil cooler (72), and then returns to the hydraulic fluid tank (74).

[0054] The third temperature sensor (75) detects the temperature Ts of the hydraulic fluid in the third flow path (73). For example, the third temperature sensor (75) detects the temperature of the hydraulic fluid in the part of the third flow path (73) that is downstream of the hydraulic cylinders (24-26) and upstream of the oil cooler (72). The third temperature sensor (75) detects the temperature of the hydraulic fluid that is discharged from the hydraulic cylinders (24-26) and before being supplied to the heat exchanger (83) described later. The third temperature sensor (75) transmits information on the detected temperature Ts of the hydraulic fluid to the controller (47).

[0055] (Heat exchange switching section (45))

[0056] The heat exchange switching section (45) has a heat exchange channel (81), a bypass channel (82), a heat exchanger (83), and a second valve (84).

[0057] The heat exchange channel (81) is a channel that branches off from the second channel (63) and joins the second channel (63) through the heat exchanger (83). The heat exchange channel (81) is arranged in parallel with the channel portion flowing around the electrical component (62) of the second channel (63). The heat exchange channel (81) branches off from the portion of the second channel (63) upstream of the electrical component (62) and downstream of the second water pump (65), and joins the portion of the second channel (63) downstream of the electrical component (62) and upstream of the second temperature sensor (66).

[0058] The bypass path (82) branches off from the second path (63) and joins the second path (63) without passing through the heat exchanger (83). The bypass path (82) is arranged in parallel with the heat exchange path (81) and the path portion flowing around the electrical component (62) of the second path (63). The bypass path (82) branches off from the upstream side of the electrical component (62) and the downstream side of the second water tank (64) of the second path (63), and joins the downstream side of the electrical component (62) and the upstream side of the second temperature sensor (66) of the second path (63).

[0059] The heat exchanger (83) is positioned between the third flow path (73) and the heat exchange flow path (81). The heat exchanger (83) performs heat exchange between the working fluid flowing through the third flow path (73) and the water flowing through the heat exchange flow path (81). The heat exchanger (83) is positioned upstream of the oil cooler (72) and downstream of the third temperature sensor (75) in the working fluid cooling circuit (44).

[0060] The second valve (84) is, for example, an electronic valve. The second valve (84) is positioned across the heat exchange path (81) and the bypass path (82). The second valve (84) switches between a state in which the heat exchange path (81) is opened and the bypass path (82) is closed, or a state in which the heat exchange path (81) is closed and the bypass path (82) is opened, by a command signal from the controller (48).

[0061] The second valve (84) has four ports Q1 to Q4. The first port Q1 is connected to the upstream portion of the heat exchange channel (81). The second port Q2 is connected to the upstream portion of the bypass channel (82). The third port Q3 is connected to the downstream portion of the heat exchange channel (81). The fourth port Q4 is connected to the downstream portion of the bypass channel (82).

[0062] The second valve (84) has a valve body (not shown). The valve body may be located at either the heat exchange operating position R1 or the heat exchange stop position R2. When the valve body of the second valve (84) moves to the heat exchange operating position R1, the first port Q1 and the third port Q3 are connected, and the second port Q2 and the fourth port Q4 are blocked. Thus, the heat exchange path (81) is opened and the bypass path (82) is blocked, so water flows in the heat exchange path (81) and does not flow in the bypass path (82). Accordingly, heat exchange is performed between the water flowing in the heat exchange path (81) and the second path (63) and the working fluid flowing in the third path (73).

[0063] When the valve body of the second valve (84) moves to the heat exchange stop position R2, the connection between the first port Q1 and the third port Q3 is blocked, and the connection between the second port Q2 and the fourth port Q4 is established. As a result, the heat exchange path (81) is blocked and the bypass path (82) is opened, so water flows through the bypass path (82) and does not flow through the heat exchange path (81). Accordingly, heat exchange between the water flowing through the second path (63) and the working fluid flowing through the third path (73) is stopped.

[0064] (Heating switch (46))

[0065] A heating switch (46) is positioned within the cap (14). The heating switch (46) is operated by an operator. When the heating switch (46) is turned on by the operator, the heating switch (46) transmits a heating on signal to the controller (47). When the heating switch (46) is turned off by the operator, the heating switch (46) transmits a heating off signal to the controller (47).

[0066] (Controller (47))

[0067] The controller (47) includes a processor such as a CPU. The processor receives information on the water temperature Tc transmitted from the first temperature sensor (56), information on the water temperature Te transmitted from the second temperature sensor (66), and information on the hydraulic fluid temperature Ts transmitted from the third temperature sensor (75). The processor performs processing for controlling the electric heater (51), the first water pump (55), the first valve (43), the second water pump (65), the second valve (84), and the hydraulic pump (71).

[0068] The controller (47) includes a memory device. The memory device includes memory such as RAM or ROM, and an auxiliary memory device such as an HDD (Hard Disk Drive) or SSD (Solid State Drive). The memory device stores a program for controlling the electric heater (51), the first water pump (55), the first valve (43), the second water pump (65), the second valve (84), and the hydraulic pump (71), an allowable temperature of temperature Te, and a reference temperature for controlling the electric heater (51).

[0069] When the controller (47) receives a heating on signal from the heating switch (46), it drives the first water pump (55) to circulate the water in the first water tank (52). When the controller (47) receives the heating on signal, it controls the electric heater (51) to turn on or off by transmitting an on signal or an off signal to the electric heater (51) so that the water temperature Tc becomes a reference temperature. When the controller (47) receives a heating off signal from the heating switch (46), it stops the operation of the first water pump (55) and turns off the electric heater (51). The reference temperature can be set, for example, to 60 degrees.

[0070] When the key of the electric shovel (1) is turned on by an operator and the key-on operation signal is received, the controller (47) drives the second water pump (65) to circulate the water in the second water tank (64). Also, when the key-on operation signal is received, the controller (47) drives the hydraulic pump (71) to supply the hydraulic fluid in the hydraulic fluid tank (74) to the hydraulic cylinders (24-26).

[0071] The controller (47) compares the water temperature Tc and the water temperature Te, and transmits a driving command to the first valve (43) to move the valve body of the first valve (43) to a joining position T1 if the temperature Tc is less than the temperature Te, and to move the valve body of the first valve (43) to a non-joining position T2 if the temperature Tc is greater than or equal to the temperature Te. In this way, when the temperature Te of the water cooling the electrical component (62) is higher than the temperature Tc of the water flowing through the heater core (53), the temperature of the water flowing through the heater core (53) can be rapidly increased by joining the heating circuit (41) and the electrical component cooling circuit (42).

[0072] The controller (47) compares the temperature of the water Te with the temperature of the working fluid Ts. If the temperature Te is less than the temperature Ts, the valve body of the second valve (84) is moved to the heat exchange operating position R1, and if the temperature Te is greater than or equal to the temperature Ts, the valve body of the second valve (84) is moved to the heat exchange stop position R2. In this way, when the temperature of the working fluid Ts is higher than the temperature Te used to cool the electrical component (62), the water of the electrical component cooling circuit (42) is flowed into the heat exchange path (81), thereby transferring heat from the working fluid to the water through the heat exchanger (83), and the temperature of the water flowing through the second path (63) can be rapidly increased. When the heating circuit (41) and the electrical component cooling circuit (42) are combined, the temperature of the water flowing through the heater core (53) can be rapidly increased. When the heating circuit (41) and the electric component cooling circuit (42) are not joined, the temperature of the water in the second flow path (63) can be rapidly increased, so the heating circuit (41) and the electric component cooling circuit (42) can be rapidly joined, and as a result, the temperature of the water flowing through the heater core (53) can be rapidly increased.

[0073] When the temperature of the water Te becomes above the allowable temperature, the controller (47) moves the valve body of the second valve (84) to the heat exchange stop position R2. The allowable temperature (an example of a predetermined temperature) can be set to a temperature that is permissible for the electrical component (62). The allowable temperature can be set, for example, to 65 degrees. Thus, when heat is being transferred from the working fluid of the working fluid cooling circuit (44) to the water of the electrical component cooling circuit (42), the heat transfer can be stopped when the temperature Te reaches the allowable temperature, thereby protecting the electrical component (62).

[0074] (Control method of the heating device (3) of the electric shovel (1))

[0075] Next, a control method for the heating device (3) of the electric shovel (1) of the present embodiment will be described. FIG. 3 is a flowchart for explaining the control operation of the heating circuit (41) of the heating device (3).

[0076] When the heating switch (46) inside the cap (14) is turned on by the operator, in step S10, the controller (47) receives a heating on signal.

[0077] When the controller (47) receives a heating on signal, in step S11, it outputs a driving command signal to the first water pump (55) and drives the first water pump (55).

[0078] Next, in step S12, the controller (47) initiates on or off control of the electric heater (51). The controller (47) controls the electric heater (51) on or off so that the water temperature Tc detected by the first temperature sensor (56) becomes a reference temperature.

[0079] Next, in step S13, the controller (47) determines whether it has received a heating off signal resulting from the operator's operation to turn off the heating switch (46). In step S13, if the heating off signal is not received, the control returns to step S12, and the controller (47) continues to control the on or off of the electric heater (51). Meanwhile, in step S13, if the heating off signal is received, the control proceeds to step S14.

[0080] In step S14, the controller (47) stops the on or off control of the electric heater (51) and turns the electric heater (51) off.

[0081] Next, in step S15, a stop command signal is output to the first water pump (55), the first water pump (55) is stopped, and control is terminated.

[0082] In this way, the controller (47) controls the on or off of the electric heater (51) from when the heating switch (46) is turned on until the heating switch (46) is turned off.

[0083] FIG. 4 is a flowchart illustrating the control operation of the electrical component cooling circuit (42), the first valve (43), the hydraulic fluid cooling circuit (44), and the heat exchange switching unit (45) of the heating device (3). The control operation shown in FIG. 4 is executed in parallel with the control operation shown in FIG. 3.

[0084] When the heating switch (46) inside the cap (14) is turned on by the operator, the controller (47) receives the heating on signal in step S10, just as above. And, since the key of the electric shovel (1) is turned on by the operator before the heating switch (46) is turned on, the controller (47) receives the key on signal, transmits a driving command to the second water pump (65) to drive the second water pump (65), and transmits a driving command to the hydraulic pump (71) to drive the hydraulic pump (71).

[0085] Next, in step S21 (first temperature acquisition step, second temperature acquisition step), the controller (47) receives information of temperature Tc from the first temperature sensor (56), receives information of temperature Te from the second temperature sensor (66), and receives information of temperature Ts from the third temperature sensor (75).

[0086] Next, in step S22, the controller (47) compares temperature Tc with temperature Te. In step S22, if temperature Tc is less than temperature Te, the control proceeds to step S23.

[0087] In step S23 (Euro control step), the controller (47) outputs a driving command signal to the first valve (43) and moves the valve body of the first valve (43) to a joining position T1. As a result, the electric component cooling circuit (42) joins the heating circuit (41), the water from the electric component cooling circuit (42) flows into the heating circuit (41), and the water flowing through the heater core (53) is rapidly heated.

[0088] Meanwhile, in step S22, if the temperature Tc is greater than or equal to the temperature Te, the control proceeds to step S24, and in step S24 (flow control step), the controller (47) outputs a driving command signal to the first valve (43) to move the valve body of the first valve (43) to a non-confluence position T2. ​​As a result, the heating circuit (41) and the electrical component cooling circuit (42) are separated, and the water of the electrical component cooling circuit (42), which has a lower temperature than the water of the heating circuit (41), does not flow into the heating circuit (41).

[0089] After steps S23 and S24, control proceeds to step S25, and in step S25, the controller (47) compares temperature Te and temperature Ts.

[0090] In step S25, if it is determined that the temperature Te is lower than the temperature Ts, the control proceeds to step S26. In step S26, the controller (47) determines whether the temperature Te is lower than the allowable temperature. In step S26, if it is determined that the temperature Te is lower than the allowable temperature, the control proceeds to step S27. In step S27, the controller (47) transmits a driving command signal to the second valve (84) and moves the valve body of the second valve (84) to the heat exchange operating position R1. By doing so, heat from the working fluid of the working fluid cooling circuit (44) can be transferred to the water of the electrical component cooling circuit (42).

[0091] Meanwhile, if in step S25 the temperature Te is determined to be greater than or equal to the temperature Ts, or in step S26 the temperature Te is determined to be greater than or equal to the allowable temperature, the control proceeds to step S28.

[0092] In step S28, the controller (47) transmits a drive command signal to the second valve (84) to move the valve body of the second valve (84) to the heat exchange stop position R2. This allows the heat exchange between the working fluid of the working fluid cooling circuit (44) and the water of the electrical component cooling circuit (42) to be stopped.

[0093] Following steps S27 and S28, control proceeds to step S29, and in step S29, the controller (47) determines whether it has received a heating off signal resulting from the operator's operation to turn off the heating switch (46). In step S29, if the heating off signal has not been received, control returns to step S22, and steps S22 through S28 are repeated.

[0094] Meanwhile, in step S29, when a heating off signal is received, the control proceeds to step S30, and in step S30, the controller (47) transmits a driving command signal to the first valve (43) to move the valve body of the first valve (43) to a non-confluence position T2, transmits a driving command signal to the second valve (84) to move the valve body of the second valve (84) to a heat exchange stop position R2, and terminates the control.

[0095] For example, when steps S23 and S27 are executed, the electrical component cooling circuit (42) joins the heating circuit (41), and heat transfer from the hydraulic fluid cooling circuit (44) to the electrical component cooling circuit (42) is performed. When steps S23 and S28 are executed, the electrical component cooling circuit (42) joins the heating circuit (41), and heat transfer from the hydraulic fluid cooling circuit (44) to the electrical component cooling circuit (42) is stopped.

[0096] When steps S24 and S27 are executed, the electrical component cooling circuit (42) is not joined to the heating circuit (41), and heat transfer from the hydraulic fluid cooling circuit (44) to the electrical component cooling circuit (42) is performed. In this case, the water in the electrical component cooling circuit (42) can be preheated before joining the electrical component cooling circuit (42) to the heating circuit (41).

[0097] When steps S24 and S28 are executed, the electrical component cooling circuit (42) does not join the heating circuit (41), and heat transfer from the hydraulic fluid cooling circuit (44) to the electrical component cooling circuit (42) is stopped.

[0098] (Features, etc.)

[0099] In the heating device (3) of the work machine of the present embodiment, a first valve (43) is installed between the heating circuit (41) and the electric component cooling circuit (42), and the electric component cooling circuit (42) is connected to the heating circuit (41) or separated from the heating circuit (41). A controller (47) operates the first valve (43) based on the detection value Tc of the first temperature sensor (56) and the detection value Te of the second temperature sensor (66).

[0100] Thus, when the temperature of the water in the heating circuit (41) is lower than the temperature of the water in the electric component cooling circuit (42), the electric component cooling circuit (42) is connected to the heating circuit (41), and the temperature of the water flowing through the heating circuit (41) can be rapidly increased. Accordingly, the time for keeping the electric heater (51) on is shortened, and the power used for heating can be reduced.

[0101] Additionally, if the temperature of the water in the heating circuit (41) is higher than the temperature of the water in the electric component cooling circuit (42), the electric component cooling circuit (42) can be separated from the heating circuit (41), and the lowering of the temperature of the water in the heating circuit (41) caused by the water of the electric component cooling circuit (42) flowing into the heating circuit (41) can be prevented.

[0102] In the heating device (3) of the work machine of the present embodiment, a heat exchange switching unit (45) capable of switching between a state in which heat can be exchanged between the working fluid cooling circuit (44) and the electrical component cooling circuit (42) and a state in which heat exchange is stopped is installed, and the controller (47) controls the heat exchange switching unit (45) based on the detection value Te of the second temperature sensor (66) and the detection value Ts of the third temperature sensor (75).

[0103] Thus, when the temperature of the water in the electrical component cooling circuit (42) is lower than the temperature of the hydraulic fluid in the hydraulic fluid cooling circuit (44), the heat exchange switching unit (45) is controlled to transfer heat from the hydraulic fluid in the hydraulic fluid cooling circuit (44) to the water in the electrical component cooling circuit (42), and the temperature of the water in the electrical component cooling circuit (42) can be rapidly increased.

[0104] In addition, since the battery (62b) installed in the electrical component cooling circuit (42) can be heated using the temperature of the working fluid, the deterioration of performance caused by the low temperature can be suppressed.

[0105] In addition, when the temperature of the water in the electrical component cooling circuit (42) is higher than the temperature of the water in the hydraulic fluid cooling circuit (44), the heat exchange switching unit (45) is controlled to prevent the transfer of heat from the water in the electrical component cooling circuit (42) to the hydraulic fluid in the hydraulic fluid cooling circuit (44), thereby preventing a decrease in the temperature of the water in the electrical component cooling circuit (42).

[0106] In the heating device (3) of the work machine of the present embodiment, the controller (47) controls the heat exchange switching unit (45) so that heat exchange is stopped when the detection value Te of the second temperature sensor (66) becomes above the allowable temperature. By doing so, it is possible to prevent the water in the electrical component cooling circuit (42) from becoming above the temperature that the electrical component (62) can tolerate.

[0107] In the heating device (3) of the work machine of the present embodiment, the controller (47) controls the first valve (43) to separate the electric component cooling circuit (42) from the heating circuit (41) when the detection value Tc of the first temperature sensor (56) is greater than or equal to the detection value Te of the second temperature sensor (66) and when the detection value Te of the second temperature sensor (66) is less than the detection value Ts of the third temperature sensor (75), and controls the heat exchange switching unit (45) to make the state heat exchangeable, and when the detection value Tc of the first temperature sensor (56) becomes less than the detection value Te of the second temperature sensor (66), the controller operates the first valve (43) to join the electric component cooling circuit (42) to the heating circuit (41). Thus, even if the temperature Tc of the water in the heating circuit (41) is lower than the temperature of the water in the electric component cooling circuit (42), if the temperature Tc of the working fluid is higher than the temperature Te of the electric component (62) that cooled the electric component, the temperature of the water flowing through the second path (63) can be rapidly increased by allowing the water in the electric component cooling circuit (42) to flow through the heat exchange path (81). Since the temperature of the water in the electric component cooling circuit (42) can be rapidly increased even when the heating circuit (41) and the electric component cooling circuit (42) are not joined, the heating circuit (41) and the electric component cooling circuit (42) can be quickly joined, and as a result, the temperature of the water flowing through the heater core (53) can be rapidly increased, and the power used for the electric heater (51) can be reduced.

[0108] (Other embodiments)

[0109] Although an embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the invention.

[0110] (A)

[0111] In the above embodiment, an electric work machine was used as an example of a work machine, but a hybrid work machine using an electric motor and an engine as the driving source may also be used.

[0112] (B)

[0113] In the above embodiment, water is used as the refrigerant for the heating circuit (41) and the electric component cooling circuit (42), but it is not limited to water.

[0114] (C)

[0115] In the above embodiment, the heat exchange flow path (81) and bypass flow path (82) of the heat exchange switching unit (45) are installed in the electrical component cooling circuit (42), but the heat exchange flow path (81) and bypass flow path (82) may also be installed in the hydraulic fluid cooling circuit (44).

[0116] (D)

[0117] In the above embodiment, an operating fluid tank (74) and an oil cooler (72) are installed in the operating fluid cooling circuit (44), but the oil cooler (72) may also serve as the operating fluid tank (74).

[0118] (E)

[0119] In the above embodiment, a shovel was used as an example of a working machine, but it is not limited to a shovel and can be applied to any working machine that uses heating, such as a wheel loader or a dump truck.

[0120] [Industrial Applicability]

[0121] According to the heating device of a work machine and the control method of the heating device of a work machine disclosed in the present disclosure, the power used for heating can be reduced, and it is useful for electric work machines, etc. Explanation of the symbols

[0122] 3: Heating device 41: Heating circuit 42: Electrical component cooling circuit 43: First valve 44: Hydraulic fluid cooling circuit 47: Controller 51: Electric heater 54: The First Euro 55: 1st water pump 56: First temperature sensor 62: Electrical Components 63: The Second Euro 66: Second temperature sensor

Claims

Claim 1 A heating device for a work machine, comprising: a heating circuit having a first flow path through which a refrigerant used for heating flows, a heating element that heats the refrigerant in the first flow path, and a first temperature sensor that detects the temperature of the refrigerant in the first flow path; an electrical component cooling circuit having a second flow path through which a refrigerant used for cooling an electrical component flows, and a second temperature sensor that detects the temperature of the refrigerant in the second flow path; a first valve disposed between the heating circuit and the electrical component cooling circuit, which connects the electrical component cooling circuit to the heating circuit or separates the electrical component cooling circuit from the heating circuit; and a controller that operates the first valve based on the detection value of the first temperature sensor and the detection value of the second temperature sensor. Claim 2 A heating device for a work machine according to claim 1, wherein the controller separates the electrical component cooling circuit from the heating circuit when the detection value of the first temperature sensor is greater than or equal to the detection value of the second temperature sensor, and operates the first valve to join the electrical component cooling circuit to the heating circuit when the detection value of the first temperature sensor is less than the detection value of the second temperature sensor. Claim 3 A heating device for a work machine according to claim 1, comprising: a hydraulic actuator; a third fluid passage through which hydraulic fluid supplied to the hydraulic actuator flows; an oil cooler for cooling the hydraulic fluid flowing through the third fluid passage; and a third temperature sensor for detecting the temperature of the hydraulic fluid in the third fluid passage; and a heat exchange switching unit capable of switching between a state in which heat exchange between the hydraulic fluid cooling circuit and the electrical component cooling circuit is possible and a state in which heat exchange between the hydraulic fluid cooling circuit and the electrical component cooling circuit is stopped; wherein the controller controls the heat exchange switching unit based on the detection value of the second temperature sensor and the detection value of the third temperature sensor. Claim 4 A heating device for a work machine according to paragraph 3, wherein the controller controls the heat exchange switching unit so that the heat exchange is stopped when the detection value of the second temperature sensor is greater than or equal to the detection value of the third temperature sensor, and controls the heat exchange switching unit so that the heat exchange is possible when the detection value of the second temperature sensor is less than the detection value of the third temperature sensor. Claim 5 A heating device for a work machine according to claim 3 or 4, wherein the controller controls the heat exchange switching unit so that the heat exchange is stopped when the detection value of the second temperature sensor becomes above a predetermined temperature. Claim 6 In paragraph 3, the controller controls the first valve to separate the electrical component cooling circuit from the heating circuit when the detection value of the first temperature sensor is greater than or equal to the detection value of the second temperature sensor and the detection value of the second temperature sensor is less than the detection value of the third temperature sensor, controls the heat exchange switching unit to make the heat exchangeable, and when the detection value of the first temperature sensor becomes less than the detection value of the second temperature sensor, operates the first valve to join the electrical component cooling circuit to the heating circuit, a heating device of a work machine. Claim 7 In paragraph 3, the heat exchange switching unit comprises: a heat exchanger capable of heat exchange between the operating fluid cooling circuit and the electrical component cooling circuit; a heat exchange path connected in parallel to either the second path of the electrical component cooling circuit or the third path of the operating fluid cooling circuit, wherein the heat exchanger is positioned therein; a bypass path connected in parallel to the heat exchange path and bypassing the heat exchanger; and a second valve switching between a state in which the heat exchange path is opened and the bypass path is closed, and a state in which the heat exchange path is closed and the bypass path is opened; wherein the controller controls the second valve based on the detection value of the second temperature sensor and the detection value of the third temperature sensor, a heating device of a working machine. Claim 8 In claim 1, the electric component comprises a motor and a capacitor for driving the motor, a heating device for a working machine. Claim 9 In paragraph 3, the electrical component comprises an electric motor and a capacitor for driving the electric motor, the hydraulic fluid cooling circuit comprises a hydraulic pump for supplying the hydraulic fluid, and the electric motor drives the hydraulic pump, a heating device for a working machine. Claim 10 In paragraph 3, the above-mentioned working fluid cooling circuit comprises a working fluid tank as an oil cooler, a heating device for a working machine. Claim 11 A method for controlling a heating device of a work machine, comprising: a first temperature acquisition step for acquiring the temperature of a refrigerant in a heating circuit including a first flow path through which a refrigerant used for heating flows and a heating element that heats the refrigerant in the first flow path; a second temperature acquisition step for acquiring the temperature of a refrigerant in an electrical component cooling circuit including a second flow path through which a refrigerant used for cooling an electrical component flows; and a flow path control step for joining the electrical component cooling circuit to the heating circuit or separating the electrical component cooling circuit from the heating circuit based on the temperature acquired in the first temperature acquisition step and the temperature acquired in the second temperature acquisition step.

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