Work machine control device, work machine, and discharge control method

Abstract

To provide a work machine control device, a work machine, and a discharge control method capable of preventing delay of start of work by the work machine caused by heating of a battery body.SOLUTION: A work machine control device 2 is a control device for a work machine 1 including a battery device 70 and a heater 8 for heating a battery body 71 of the battery device 70. The working machine control device 2 includes the controller 3 which determines whether or not the temperature condition that the battery temperature which is the temperature of the battery body 71 is equal to or higher than the first temperature threshold value is satisfied, determines whether or not the output condition that the dischargeable output value of the battery body 71 is equal to or higher than the output threshold value is satisfied, and permits the discharge from the battery body 71 when one or both of the temperature condition and the output condition are satisfied.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a technique for a work machine equipped with a battery device. [Background technology]

[0002] In a work machine equipped with a battery device as a power source, a heating system is required to heat the battery body (cells) until the battery body (cells) reaches a discharge capacity corresponding to the work capacity required for the work machine. For example, Patent Document 1 discloses a hybrid construction machine including a prime mover, an electric motor that generates electricity and assists the power of the prime mover, a power storage device that exchanges power with the electric motor, a warm-up circuit that circulates a heating medium near the power storage device, and a control device that controls the circulation of the heating medium in the warm-up circuit. This hybrid construction machine is equipped with an onboard equipment status detection unit that detects the status of the onboard equipment to estimate the output required of the onboard equipment for the power storage device, and the control device controls the circulation of the heating medium based on the temperature of the power storage device and a threshold temperature that determines whether to circulate the heating medium in the warm-up circuit, and changes the threshold temperature depending on the detection result of the onboard equipment status detection unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 110250 Summary of the Invention [Problem to be solved by the invention]

[0004] In the construction machine of Patent Document 1, the control device controls the circulation of the heating medium, i.e., the warm-up operation of the power storage device, based on the temperature of the power storage device and the threshold temperature, which may delay the start of work by the work machine. Specifically, the discharge output of the battery body is affected not only by the temperature of the battery body (cell temperature), but also by various factors (factors that reduce the discharge output), such as the state of charge (SOC) of the battery body and the degree of deterioration of the battery body. Because the discharge output of the battery body is not uniquely determined by cell temperature alone, the threshold temperature used to determine whether to stop heating the battery body must be set to a value with some leeway. This increases the time it takes to complete heating of the battery body, causing a delay in the start of work by the work machine.

[0005] An object of the present disclosure is to provide a work machine control device, a work machine, and a discharge control method that can reduce delays in the start of work by the work machine due to heating of the battery body. [Means for solving the problem]

[0006] A work machine control device according to a first aspect is a control device for a work machine that includes a battery device and a heater that warms the battery main body of the battery device. The work machine control device includes a controller that determines whether a temperature condition is satisfied that the battery temperature, which is the temperature of the battery main body, is equal to or higher than a first temperature threshold, and determines whether an output condition is satisfied that the dischargeable output value of the battery main body is equal to or higher than an output threshold, and that permits discharge from the battery main body when one or both of the temperature condition and the output condition are satisfied.

[0007] In a first aspect, the controller determines whether the temperature condition and the output condition are satisfied, and permits discharge from the battery body when one or both of these conditions are satisfied. That is, even if the battery temperature is below the first temperature threshold and the temperature condition is not satisfied, the controller permits discharge from the battery body when the dischargeable output value reaches or exceeds the output threshold and the output condition is satisfied. On the other hand, if the timing at which the output condition is satisfied is later than the timing at which the temperature condition is satisfied due to factors that cause a decrease in discharge output, such as the state of charge (SOC) and the degree of deterioration of the battery body, the controller permits discharge from the battery body when the temperature condition is satisfied. Therefore, the work machine control device according to the first aspect can reduce delays in the start of work by the work machine caused by warming of the battery body, even if the first temperature threshold is set to a value with a margin of error.

[0008] A work machine control device according to a second aspect preferably includes the following configuration in addition to the work machine control device according to the first aspect. That is, in the work machine control device according to the second aspect, it is preferable that the controller continues heating the battery main body by the heater even when one or both of the temperature condition and the output condition are satisfied by heating the battery main body by the heater, and stops heating the battery main body by the heater when the battery temperature reaches a second temperature threshold higher than the first temperature threshold. For example, when a work machine performs light-load work, which is work with a small load, the amount of heat generated by the work machine itself decreases. In this case, after one or both of the temperature condition and the output condition are satisfied, the battery temperature is likely to again fall below the first temperature threshold, or the dischargeable output value is likely to again fall below the output threshold. Therefore, in this second aspect, the controller performs control to continue heating the battery main body until the battery temperature reaches the second temperature threshold, even after one or both of the temperature condition and the output condition are satisfied and discharge from the battery main body is permitted. Therefore, the work machine control device according to the second aspect can suppress delays in the start of work, while reducing the frequency with which work is interrupted due to a drop in the battery temperature after discharge from the battery main body is permitted.

[0009] A work machine control device according to a third aspect preferably includes the following configuration in addition to the work machine control device according to the second aspect. That is, in the work machine control device according to the third aspect, it is preferable that the controller resumes heating of the battery main body by the heater when the battery temperature drops to or below a third temperature threshold that is greater than the first temperature threshold and less than the second temperature threshold. In this third aspect, the controller resumes heating of the battery main body by the heater when the battery temperature drops to or below the third temperature threshold, which is a temperature between the first temperature threshold and the second temperature threshold, thereby further reducing the frequency of work interruptions.

[0010] A work machine control device according to a fourth aspect is a control device for a work machine equipped with a battery device and a heater that warms the battery body of the battery device, and includes a controller that permits discharge from the battery body when an output condition is satisfied that the dischargeable output value of the battery body is equal to or greater than an output threshold. In this fourth aspect, the controller determines whether to permit discharge from the battery body based on the dischargeable output value of the battery body itself at that time, making it possible to reduce delays in the start of work by the work machine due to heating of the battery body. Also, in this fourth aspect, it is preferable that the controller permits discharge from the battery body when one or both of the temperature condition that the battery temperature, which is the temperature of the battery body, is equal to or greater than a first temperature threshold and the output condition are satisfied.

[0011] A work machine according to a fifth aspect includes the battery device, the heater, and the work machine control device according to any one of the first to fourth aspects.

[0012] A discharge control method according to a sixth aspect is a method for a work machine equipped with a battery device and a heater for heating the battery body of the battery device, and includes a controller determining whether a temperature condition is satisfied in which the battery temperature, which is the temperature of the battery body, is equal to or higher than a first temperature threshold, the controller determining whether an output condition is satisfied in which the dischargeable output value of the battery body is equal to or higher than an output threshold, and the controller allowing discharge from the battery body when one or both of the temperature condition and the output condition are satisfied. [Effects of the Invention]

[0013] According to the present disclosure, a work machine control device, a work machine, and a discharge control method are provided that can reduce delays in the start of work by the work machine due to heating of the battery body. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a side view of a work machine according to an embodiment of the present disclosure; FIG. [Figure 2] FIG. 2 is a plan view of the upper rotating body of the work machine as seen from above, showing a state in which an outer wall defining a machine room has been removed. [Figure 3] FIG. 2 is a perspective view showing a battery device, an electric motor, and a hydraulic pump in the work machine. [Figure 4] FIG. 2 is a diagram showing a hot water circuit in the work machine. [Figure 5] 4 is a flowchart showing an example of a calculation process performed by a controller of the work machine control device. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0016] The work machine 1 according to this embodiment shown in Fig. 1 is an electrically powered work machine equipped with a battery device as a power source for a hydraulic pump. The work machine 1 shown in Fig. 1 is a hydraulic excavator.

[0017] The work machine 1 comprises a lower running body 10 capable of running on the ground G, an upper rotating body 12 mounted on the lower running body 10 so as to be rotatable around a rotation center axis Cs extending in the vertical direction, and a work device 14 mounted on the upper rotating body 12.

[0018] The lower traveling body 10 includes a pair of right crawlers 11R and left crawlers 11L disposed on the right and left, respectively. The right crawlers 11R and left crawlers 11L operate so that the lower traveling body 10 travels on the ground G.

[0019] The upper rotating body 12 includes a rotating frame 16 , a cab 18 serving as an operator's compartment, a battery device 70 , an electric motor 30 , a hydraulic pump 40 , a tank 80 , a counterweight 50 , and an outer wall 60 .

[0020] The rotating frame 16 is a member that constitutes the base portion of the upper rotating body 12, and supports the cab 18, the battery device 70, the electric motor 30, the hydraulic pump 40, the tank 80, the counterweight 50, and the outer wall 60. The cab 18 is located in the front of the upper rotating body 12, on the left side of the work implement 14. However, the cab 18 may also be located on the right side of the work implement 14.

[0021] The outer wall 60 defines a machine room 60S. The outer wall 60 is disposed, for example, behind the cab 18. The outer wall 60 may be disposed not only behind the cab 18 but also to the side of the cab 18. The outer wall 60 includes an upper wall disposed above the revolving frame 16, a rear wall extending from the revolving frame 16 to the rear edge of the upper wall, a right wall extending from the revolving frame 16 to the right edge of the upper wall, a left wall extending from the revolving frame 16 to the left edge of the upper wall, and a front wall extending from the revolving frame 16 to the front edge of the upper wall. The rear wall of the outer wall 60 has a curved shape (for example, an arc shape) as shown in FIG. 2 .

[0022] Inside the machinery room 60S, electric equipment including a battery device 70 and an electric motor 30, and hydraulic equipment including a hydraulic pump 40 and a tank 80 are arranged. The tank 80 stores hydraulic oil to be supplied to the hydraulic pump 40. The battery device 70, the electric motor 30, the hydraulic pump 40, and the counterweight 50 will be described later.

[0023] The work device 14 includes a boom 21, an arm 22, and a bucket 24. The boom 21 is supported by the swivel frame 16 so as to be able to be raised and lowered. The arm 22 is attached to the tip of the boom 21 so as to be able to rotate up and down relative to the boom 21. The bucket 24 is attached to the tip of the arm 22 so as to be able to rotate up and down relative to the arm 22. The bucket 24 is a tip attachment used, for example, for excavation work. The tip attachment is not limited to the bucket 24, and may be other devices such as a fork, a grapple, or a lifting magnet.

[0024] The work machine 1 has a boom cylinder 26, an arm cylinder 27, and a bucket cylinder 28. The boom cylinder 26 is a hydraulic cylinder that extends and retracts so as to rotate the boom 21 in the hoisting direction when hydraulic oil is supplied from the hydraulic pump 40. The arm cylinder 27 is a hydraulic cylinder that extends and retracts so as to rotate the arm 22 in the up and down direction when hydraulic oil is supplied from the hydraulic pump 40. The bucket cylinder 28 is a hydraulic cylinder that extends and retracts so as to rotate the bucket 24 in the up and down direction relative to the arm 22 when hydraulic oil is supplied from the hydraulic pump 40.

[0025] Next, the battery device 70, electric motor 30, hydraulic pump 40, and counterweight 50 will be described. Fig. 2 is a plan view of the upper rotating body 12 of the work machine 1 as seen from above, showing a state in which the outer wall 60 that defines the machine room 60S has been removed. Fig. 3 is a perspective view showing the battery device 70, electric motor 30, and hydraulic pump 40 of the work machine 1.

[0026] The battery device 70, the electric motor 30, and the hydraulic pump 40 are disposed inside the machine room 60S.

[0027] The battery device 70 is disposed at the rear of the revolving frame 16. The electric motor 30 is driven by the battery device 70. The hydraulic pump 40 is driven by the electric motor 30.

[0028] As shown in Fig. 3, the hydraulic pump 40 is disposed below (directly below) the electric motor 30. In this embodiment, the electric motor 30 and the hydraulic pump 40 are disposed side by side vertically, which makes it easier to ensure space for disposing the electric motor 30 and the hydraulic pump 40 in the limited space in the machine room 60S of the work machine 1 compared to when they are disposed side by side, front to back or side to side. The electric motor 30 and the hydraulic pump 40 may be disposed side by side, front to back, or side to side. The hydraulic pump 40 may also be disposed above the electric motor 30.

[0029] Furthermore, by arranging the hydraulic pump 40 so that it is aligned vertically with the electric motor 30, the electric motor 30 and the hydraulic pump 40 can be arranged in the limited space of the machinery room 60S without interfering with the counterweight 50, the battery device 70, the cab 18, etc. Furthermore, it becomes easy to adjust the position when fixing the hydraulic pump 40 to the electric motor 30.

[0030] The rotation shaft (not shown) of the electric motor 30 may be oriented in a direction parallel to the vertical direction, or may be oriented in a direction inclined relative to the vertical direction. The inclination angle of the rotation shaft of the electric motor 30 with respect to the vertical direction may be set within a range of 0 to 45 degrees, for example. The rotation shaft of the electric motor 30 may also be oriented in a direction parallel to the horizontal direction.

[0031] The electric motor 30 and the hydraulic pump 40 are disposed adjacent to the battery device 70. In this case, it is possible to prevent the wiring for supplying power from the battery device 70 to the electric motor 30 from becoming too long. Note that the electric motor 30 and the hydraulic pump 40 do not necessarily have to be disposed adjacent to the battery device 70.

[0032] The counterweight 50 is arranged to cover one or both of the side of the electric motor 30 and the side of the hydraulic pump 40. Even if the upper rotating body 12 comes into contact with a surrounding structure while rotating, the counterweight 50 can mitigate the impact on the electric motor 30 and the hydraulic pump 40 at the time of contact. In the specific example shown in FIG. 2, the electric motor 30 and the hydraulic pump 40 are located between the battery device 70 and the counterweight 50 when viewed from above. The counterweight 50 has a curved shape (for example, an arc shape) as shown in FIG. 2.

[0033] In the specific example shown in FIG. 3 , the counterweight 50 is arranged to cover the left side and rear side of the hydraulic pump 40. However, the counterweight 50 may be arranged to cover only one of the left side, right side, and rear side of the hydraulic pump 40, or may be arranged to cover only one of the left side, right side, and rear side of the electric motor 30. Furthermore, when the counterweight 50 covers the side of the electric motor 30, the counterweight 50 does not have to cover the entire range from the lower end to the upper end of the electric motor 30, but may cover only a portion of the entire range from the lower end to the upper end of the electric motor 30. Furthermore, when the counterweight 50 covers the side of the hydraulic pump 40, the counterweight 50 does not have to cover the entire range from the lower end to the upper end of the hydraulic pump 40, but may cover only a portion of the entire range from the lower end to the upper end of the hydraulic pump 40.

[0034] 2, the battery device 70 is disposed near the center in the left-right direction and at the rear in the front-rear direction of the revolving frame 16. The battery device 70 includes a battery main body 71, a battery case 72 that houses the battery main body 71, and a support member 73 that is supported by the battery case 72.

[0035] The battery body 71 is a battery that supplies power to the electric motor 30, and may be a secondary battery such as a lithium-ion battery. The battery body 71 has, for example, a plurality of cells 71A. The battery body 71 is configured to be able to supply power to the electric motor 30 when discharge is permitted by the controller 3, which will be described later. The battery body 71 can be charged using a charging device (not shown).

[0036] The battery case 72 includes a lower plate, an upper wall disposed above the lower plate, a rear wall extending downward from the rear edge of the upper plate, a right wall extending downward from the right edge of the upper plate, a left wall extending downward from the left edge of the upper plate, and a front wall extending downward from the front edge of the upper plate.

[0037] The support member 73 supports one or both of the electric motor 30 and the hydraulic pump 40. By using the battery case 72 to support one or both of the electric motor 30 and the hydraulic pump 40 in this manner, an increase in the number of parts can be suppressed.

[0038] 3, the support member 73 supports the electric motor 30, and the shaft of the electric motor 30 is connected to the hydraulic pump 40. Specifically, the electric motor 30 may have a flange (not shown) that extends outward from its outer periphery, and may be fixed to the support member 73 by a plurality of bolts (not shown) that are inserted into a plurality of bolt through-holes (not shown) formed in the flange. The hydraulic pump 40 may be supported by a second support member (not shown) that is disposed on the revolving frame 16.

[0039] The battery case 72 has a vertical wall 72W that extends vertically and is interposed between the battery main body 71 and the electric motor 30 and hydraulic pump 40. In the specific example of Figures 2 and 3, the vertical wall 72W is the left wall of the battery case 72. However, the vertical wall 72W is not limited to the left wall of the battery case 72, and may be the right wall, rear wall, or front wall of the battery case 72.

[0040] The support member 73 is supported by the vertical wall 72W in a position that protrudes from the vertical wall 72W. In this case, the height position of the support member 73 with respect to the vertical wall 72W can be designed within the range of the dimension of the vertical wall 72W in the height direction. In other words, there is a large degree of freedom in determining the relative position of the support member 73 with respect to the vertical wall 72W in the height direction. Therefore, it is easy to lay out the support member 73 with respect to the vertical wall 72W at a height position that corresponds to the sizes of the electric motor 30 and the hydraulic pump 40.

[0041] 2 and 3, the support member 73 includes a plate member having an upper surface that extends leftward from the vertical wall 72W (left wall) of the battery case 72, a reinforcing plate that extends downward from the rear edge of the plate member, and a reinforcing plate that extends downward from the front edge of the plate member. The plate member of the support member 73 is formed with an opening 73A in which the lower part of the electric motor 30 is disposed.

[0042] The work machine 1 includes a base frame disposed below the battery case 72, and a plurality of mount buffer members 92 interposed between the base frame and the battery case 72. The plurality of mount buffer members 92 can reduce vibrations transmitted to the battery body housed in the battery case 72, as well as to the electric motor 30 and hydraulic pump 40 supported on the battery case 72 via support members 73. In this embodiment, the base frame is the revolving frame 16, but it may also be, for example, a separate member disposed on the revolving frame 16.

[0043] 2 and 3, the multiple mount buffer members 92 include four mount buffer members 92 arranged directly below the battery case 72 and near the four corners of the battery case 72. Each of the multiple mount buffer members 92 includes a buffer material (vibration-damping material) for damping vibrations that occur while the work machine 1 is operating.

[0044] As shown in Fig. 3, the hydraulic pump 40 has a suction port 40P to which one end of a suction pipe 90 is connected. As shown in Fig. 2, the other end of the suction pipe 90 is connected to a tank 80. The hydraulic pump 40 is connected to the tank 80 via the suction pipe 90. As a result, the hydraulic oil stored in the tank 80 is supplied to the hydraulic pump 40 via the suction pipe 90.

[0045] In this embodiment, the hydraulic pump 40 is disposed next to the battery case 72, and the tank 80 is disposed on the opposite side of the battery case 72 from the hydraulic pump 40. The hydraulic pump 40 is disposed below the electric motor 30, and the suction pipe 90 is disposed in the space between the battery case 72 and the revolving frame 16. By disposing the hydraulic pump 40 below the electric motor 30 in this way, it becomes easier to route the suction pipe 90 to the tank 80 through the space between the battery case 72 and the revolving frame 16.

[0046] [Work machine control device] The work machine 1 is equipped with at least one water jacket 8 as a heater, and a work machine control device 2. The work machine control device 2 is equipped with a controller 3.

[0047] The controller 3 includes a computer having an arithmetic processing unit and a memory. The controller 3 performs control to permit discharge from the battery main body 71 based on temperature conditions and output conditions, which will be described later. The relevant functions of the controller 3 are realized by the arithmetic processing unit executing a control program stored in the memory.

[0048] Fig. 4 is a diagram showing a hot water circuit in the work machine 1. As shown in Fig. 4, this hot water circuit includes a tank 19, a hot water pump 5, at least one heater 6 (a plurality of heaters 6 in the specific example shown in Fig. 4), an on-off valve 7, at least one water jacket 8 (a plurality of water jackets 8 in the specific example shown in Fig. 4), and an on-off valve 9.

[0049] The hot water pump 5 is a pump for circulating the water in the tank 19 through the hot water circuit. The controller 3 controls the operation of the hot water pump 5. In response to a command from the controller 3, the hot water pump 5 switches between a state in which water is circulated through the hot water circuit and a state in which water circulation is stopped.

[0050] The heaters 6 heat the circulating water flowing through the hot water circuit. The controller 3 controls the operation of the heaters 6. In response to a command from the controller 3, the heaters 6 switch between a state in which the circulating water is heated and a state in which the water is not heated.

[0051] The on-off valve 7 is disposed upstream of the plurality of water jackets 8 in the hot water circuit, and the on-off valve 9 is disposed downstream of the plurality of water jackets 8 in the hot water circuit. The controller 3 controls the open / closed state of the on-off valve 7 and the open / closed state of the on-off valve 9. The on-off valve 7 and the on-off valve 9 each switch their open / closed states in response to commands from the controller 3.

[0052] In this embodiment, the battery device 70 includes a battery body 71. The battery body 71 may include a plurality of cells 71A. The plurality of water jackets 8 heat the plurality of cells 71A, respectively.

[0053] The work machine 1 is equipped with a temperature detector that detects the temperature of the battery main body 71. The temperature detector may include multiple temperature sensors 4 that detect the temperatures of the multiple cells 71A, respectively. Each of the multiple temperature sensors 4 inputs its detection result to the controller 3. The controller 3 determines the temperature of the battery main body 71 using the multiple detection results input from the multiple temperature sensors 4. Specifically, for example, the controller 3 may determine the average value of the multiple detection results input from the multiple temperature sensors 4 as the temperature of the battery main body 71. Note that the number of temperature sensors 4 does not necessarily have to correspond to the number of multiple cells 71A. For example, the work machine 1 may be equipped with only a single temperature sensor 4, and that temperature sensor 4 may detect the temperature of any one of the multiple cells 71A.

[0054] The controller 3 determines whether a temperature condition is satisfied, that is, the battery temperature T, which is the temperature of the battery main body 71, is equal to or greater than a first temperature threshold T1, and whether an output condition is satisfied, that the dischargeable output value SOF (State of Function) of the battery main body 71 is equal to or greater than an output threshold SOF1. If one or both of the temperature condition and the output condition are satisfied, the controller 3 permits discharge from the battery main body 71. That is, even if the battery temperature T is less than the first temperature threshold T1 and the temperature condition is not satisfied, if the dischargeable output value SOF is equal to or greater than the output threshold SOF1 and the output condition is satisfied, the controller 3 permits discharge from the battery main body 71. On the other hand, if the timing at which the output condition is satisfied is later than the timing at which the temperature condition is satisfied due to factors that reduce discharge output, such as the state of charge (SOC) and the degree of deterioration of the battery main body 71, the controller 3 permits discharge from the battery main body 71 when the temperature condition is satisfied. Therefore, the work machine control device 2 according to this embodiment can reduce the likelihood of delays in the start of work by the work machine 1 due to heating of the battery main body 71, even if the first temperature threshold T1 is set to a value with a margin of error.

[0055] The controller 3 may calculate the available discharge output value SOF based on the battery temperature T at that time and the cause of the discharge output decrease.

[0056] The discharge output reduction factor may include the state of charge (SOC) of the battery main body 71. In this case, the controller 3 may store in advance a map (e.g., a predetermined calculation formula, a predetermined look-up table, etc.) that represents the relationship between the battery temperature T, the SOC, and the dischargeable output value SOF, and may calculate the dischargeable output value SOF based on the map, the battery temperature T at that time, and the SOC at that time.

[0057] The discharge output reduction factors may include the state of charge (SOC) of the battery main body 71 and the state of health (SOH) of the battery main body 71. In this case, the controller 3 may store in advance a map (e.g., a predetermined calculation formula, a predetermined look-up table, etc.) that represents the relationship between the battery temperature T, the SOC, the state of health (SOH), and the dischargeable output value SOF, and may calculate the dischargeable output value SOF based on the map, the battery temperature T at that time, the SOC at that time, and the state of health (SOH) at that time.

[0058] Furthermore, the controller 3 continues heating the battery main body 71 by the water jacket 8 even when one or both of the temperature condition and the output condition are satisfied by heating the battery main body 71 by the water jacket 8 as the heater, and stops heating the battery main body 71 by the water jacket 8 when the battery temperature T reaches a second temperature threshold T2 that is higher than the first temperature threshold T1. For example, when the work machine 1 is performing light-load work, which is work with a small load, the amount of heat generated by the work machine 1 itself decreases. In this case, after one or both of the temperature condition and the output condition are satisfied, the battery temperature T is likely to again fall below the first temperature threshold T1, or the dischargeable output value SOF is likely to again fall below the output threshold SOF1. Therefore, in this embodiment, the controller 3 performs control to continue heating the battery main body 71 until the battery temperature T reaches the second temperature threshold T2, even after one or both of the temperature condition and the output condition are satisfied and discharge from the battery main body 71 is permitted. Therefore, the work machine control device 2 according to this embodiment can suppress delays in the start of work, while reducing the frequency with which work is interrupted due to a drop in battery temperature T after discharge from the battery main body 71 is permitted.

[0059] Furthermore, when the battery temperature T drops to or below a third temperature threshold T3 that is greater than the first temperature threshold T1 and less than the second temperature threshold T2, the controller 3 resumes heating of the battery main body 71 by the water jacket 8. When the battery temperature T drops to or below the third temperature threshold T3, which is a temperature between the first temperature threshold T1 and the second temperature threshold T2, the controller 3 resumes heating of the battery main body 71 by the water jacket 8, thereby further reducing the frequency of work interruptions.

[0060] FIG. 5 is a flowchart showing an example of the calculation process performed by the controller 3 of the work machine control device 2.

[0061] The controller 3 starts up the battery system including the hot water circuit (step S101).

[0062] The controller 3 determines whether or not to permit discharge from the battery main body 71 (step S102). Specifically, the controller 3 determines whether or not a temperature condition is satisfied that the battery temperature T is equal to or higher than a first temperature threshold T1, determines whether or not an output condition is satisfied that the dischargeable output value SOF is equal to or higher than an output threshold SOF1, and permits discharge from the battery main body 71 if one or both of the temperature condition and the output condition are satisfied (YES in step S102).

[0063] When discharge from the battery main body 71 is permitted, the controller 3 switches the connection state of the electric circuit (not shown) so that power is supplied from the battery main body 71 to the electric motor 30. This starts discharge from the battery main body 71 (step S103).

[0064] Then, even if one or both of the temperature conditions and the output conditions are satisfied by the heating of the battery main body 71 by the water jacket 8 (YES in step S102), the controller 3 continues to heat the battery main body 71 by the water jacket 8 in the hot water circuit.

[0065] On the other hand, if neither the temperature condition nor the output condition is satisfied, the controller 3 does not permit discharge from the battery main body 71 (NO in step S102). In this case, the controller 3 performs control to start heating the battery main body 71 (step S104) and performs the processes in and after step S102. Specifically, in step S104, the controller 3 outputs a command to operate the hot water pump 5, outputs a command to start heating the circulating water by the heater 6, and outputs a command to switch each of the on-off valves 7 and 9 to an open state. As a result, in the hot water circuit shown in FIG. 4, high-temperature circulating water flows into each of the multiple water jackets 8, and each of the multiple water jackets 8 heats the corresponding battery main body 71.

[0066] In step S105, the controller 3 determines whether or not the battery main body 71 is being heated. For example, if information related to a flag indicating whether or not the battery main body 71 is being heated is stored in the memory of the controller 3, the controller 3 may determine whether or not the battery main body 71 is being heated based on the flag.

[0067] Next, the controller 3 determines whether or not to stop heating the battery main body 71 (step S106). Specifically, when the battery temperature T reaches the second temperature threshold T2 (YES in step S106), the controller 3 stops heating the battery main body 71 by the water jacket 8 in the hot water circuit (step S107). On the other hand, when the battery temperature T is less than the second temperature threshold T2 (NO in step S106), the controller 3 continues heating the battery main body 71 by the water jacket 8 in the hot water circuit and performs the processes from step S105 onwards.

[0068] Next, the controller 3 determines whether or not to resume heating of the battery main body 71 (step S108). Specifically, when the battery temperature T drops to or below the third temperature threshold T3 (YES in step S108), the controller 3 resumes heating of the battery main body 71 by the water jacket 8 in the hot water circuit (step S109), and performs the processing from step S105 onwards.

[0069] [Variations] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and includes, for example, the following modified examples.

[0070] (A) Work machine control devices In the embodiment, the work machine control device 2 is mounted on the work machine 1, but it may also be configured, for example, by an external device (not shown) that is located at a location remote from the work machine 1. The external device may be, for example, a remote control device for remotely controlling the work machine, a device for automatically driving the work machine, or a device such as a server that manages work by the work machine.

[0071] (B) About the heater In the embodiment, the work machine 1 is provided with at least one water jacket 8 as a heater, but the heater may be another device such as an electric heating sheet including an electric heating wire.

[0072] (C) About the Controller In the embodiment, the controller 3 is configured to continue heating the battery main body 71 by the heater even when one or both of the temperature conditions and the output conditions are satisfied by the heating of the battery main body 71 by the heater, and to perform control to stop heating the battery main body 71 by the heater when the battery temperature T reaches a second temperature threshold T2 that is higher than the first temperature threshold T1, but this control may be omitted.

[0073] In the embodiment, the controller 3 is configured to perform control to resume heating of the battery main body 71 by the heater when the battery temperature T drops below a third temperature threshold T3 that is greater than the first temperature threshold T1 and less than the second temperature threshold T2, but this control may be omitted.

[0074] (D) Second temperature threshold T2 and third temperature threshold T3 The controller 3 may perform control to stop heating of the battery main body 71 by the heater when the battery temperature T reaches a second temperature threshold T2 or when the dischargeable output value SOF reaches a second output threshold SOF2 that is greater than the output threshold SOF1.

[0075] In addition, the controller 3 may perform control to resume heating of the battery main body 71 by the heater when the battery temperature T falls below a third temperature threshold T3 that is greater than the first temperature threshold T1 and less than the second temperature threshold T2, or when the dischargeable output value SOF falls below a third output threshold SOF3 that is greater than the output threshold SOF1 and less than the second output threshold SOF2.

[0076] (E) The work machine in this disclosure is not limited to a hydraulic excavator. The work machine may be other machines, such as a crane or a bulldozer. Furthermore, the undercarriage 10 is not limited to a type equipped with a crawler travel device, but may be a type equipped with a travel device having tires.

[0077] Other Aspects of the Disclosure A work machine control device 2 according to another aspect of the present disclosure is a control device for a work machine 1 equipped with a battery device 70 and a heater (e.g., a water jacket 8) that warms a battery main body 71 of the battery device 70, and includes a controller 3 that permits discharge from the battery main body 71 when an output condition is satisfied that the dischargeable output value of the battery main body 71 is equal to or greater than an output threshold. In this other aspect, the controller 3 determines whether to permit discharge from the battery main body 71 based on the dischargeable output value of the battery main body 71 at that time, thereby making it possible to reduce delays in the start of work by the work machine 1 due to heating of the battery main body 71. Also, in this other aspect, it is preferable that the controller 3 permits discharge from the battery main body 71 when one or both of the temperature condition, that is, the battery temperature, of the battery main body 71 is equal to or greater than a first temperature threshold, and the output condition are satisfied. However, in this other aspect, the controller 3 does not necessarily have to make a determination using the temperature condition, and it is sufficient to determine whether to permit discharge from the battery main body 71 using at least the output condition. [Explanation of symbols]

[0078] 1: Work machine 2: Work machine control device 3: Controller 4: Temperature sensor 8: Water jacket (an example of a heater) 30: Electric motor 40: Hydraulic pump 70: Battery device 71: Battery body 71A: Cell 72: Battery case SOC: State of Charge SOF: Dischargeable output value SOF1: Output threshold T: Battery temperature T1: First temperature threshold T2: Second temperature threshold T3: Third temperature threshold

Claims

1. A work machine control device for a work machine including a battery device and a heater that heats a battery main body of the battery device, A work machine control device including a controller that determines whether a temperature condition is satisfied that the battery temperature, which is the temperature of the battery main body, is equal to or higher than a first temperature threshold, and determines whether an output condition is satisfied that the dischargeable output value of the battery main body is equal to or higher than an output threshold, and permits discharge from the battery main body when one or both of the temperature condition and the output condition are satisfied.

2. 2. The work machine control device according to claim 1, wherein the controller continues heating the battery body by the heater even when one or both of the temperature condition and the output condition are satisfied by heating the battery body by the heater, and stops heating the battery body by the heater when the battery temperature reaches a second temperature threshold that is higher than the first temperature threshold.

3. 3. The work machine control device according to claim 2, wherein the controller resumes heating of the battery body by the heater when the battery temperature drops to or below a third temperature threshold that is greater than the first temperature threshold and less than the second temperature threshold.

4. A work machine control device for a work machine including a battery device and a heater that heats a battery main body of the battery device, A work machine control device comprising: a controller that permits discharge from the battery main body when an output condition is satisfied that a dischargeable output value of the battery main body is equal to or greater than an output threshold value.

5. the battery device; The heater; A work machine comprising: the work machine control device according to any one of claims 1 to 4.

6. A discharge control method for a work machine equipped with a battery device and a heater that heats a battery main body of the battery device, comprising: A controller determines whether a temperature condition is satisfied that a battery temperature, which is a temperature of the battery body, is equal to or higher than a first temperature threshold; The controller determines whether an output condition is satisfied that a dischargeable output value of the battery main body is equal to or greater than an output threshold value; the controller permits discharge from the battery body when one or both of the temperature condition and the output condition are satisfied.

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