Construction machinery

Abstract

A construction machine (1000) comprising a battery (1), at least one electric drive device (2) supplied by the battery (1), a hydraulic circuit (3) in which hydraulic oil (4) circulates, at least one hydraulic drive device (5) supplied by the hydraulic circuit (3), and a first cooling circuit (6) for cooling the battery (1) and the hydraulic oil (4), wherein a part of the hydraulic oil (4) circulates as a refrigerant in the first cooling circuit (6).

Description

Technical Field

[0001] The present invention is based on the problem of providing a construction machine having a cooling component to be cooled with a cooling concept that is as efficient as possible.

Background Art

[0002] A construction machine includes a rechargeable battery and at least one electric drive device having at least one electric motor supplied with energy from the battery. The battery can be arranged, for example, in the construction machine.

[0003] The construction machine further includes a hydraulic circuit in which hydraulic oil circulates.

[0004] The construction machine further includes at least one hydraulic drive device supplied from the hydraulic circuit. Up to this point, reference may be made, for example, to the applicant's International Publication No. WO 2013 / 045167, which shows such a hydraulic circuit and associated hydraulic drive devices.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] The construction machine further includes a first cooling circuit for cooling the battery and the hydraulic oil, and at least a part of the hydraulic oil circulates as a refrigerant in the first cooling circuit. The part of the hydraulic oil used as the refrigerant can be obtained, for example, with a suction return filter as disclosed in International Publication No. WO 2013 / 045167.

Summary of the Invention

[0007] In one embodiment, the first cooling circuit includes a hydraulic oil pump for generating an adjustable volume flow rate of a portion of the hydraulic oil, a first cooler having an adjustable cooling capacity through which a portion of the hydraulic oil flows, and a first heat exchanger connected downstream of the first cooler and thermally coupled to the battery through which a portion of the hydraulic oil flows. The cooling capacity of the first cooler can be adjusted, for example, by a fan that generates an adjustable cooling air flow at a variable fan speed. The first cooler can also be designed, for example, as a heat pump. The first cooler can be arranged, for example, within / on the support legs of a self-propelled concrete pump.

[0008] In one embodiment, the construction machine further includes a battery temperature regulator designed to adjust the battery temperature to a predetermined target value, and the adjustment amount of the battery temperature regulator is the cooling capacity of the first cooler. The predetermined target value of the battery temperature can be, for example, within the range of room temperature.

[0009] In one embodiment, the construction machine further includes a hydraulic oil temperature regulator designed to adjust the hydraulic oil temperature to a predetermined target value, and the adjustment amount of the hydraulic oil temperature regulator is the volume flow rate of a portion of the hydraulic oil. The predetermined target value of the hydraulic oil temperature can be, for example, in the range of 30°C to 60°C.

[0010] In one embodiment, the hydraulic oil temperature regulator is parameterized (traeger) to be slower than the battery temperature regulator in order to avoid oscillation of the combined control circuit as much as possible.

[0011] In one embodiment, at least one electric drive device, for example in the form of an electric motor, is cooled by the first cooling circuit.

[0012] In one embodiment, the construction machine includes power electronics, for example in the form of a frequency converter, for controlling at least one electric drive device, and the power electronics are also cooled by the hydraulic oil.

[0013] In one embodiment, the first cooling circuit includes a second cooler through which a part of the hydraulic oil flows, and a second heat exchanger that is connected downstream of the second cooler and thermally coupled to the power electronics and through which a part of the hydraulic oil flows.

[0014] In one embodiment, the construction machine includes a second cooling circuit for cooling the power electronics, and another part of the hydraulic oil circulates as a refrigerant in the second cooling circuit.

[0015] In one embodiment, the first cooling circuit has a bypass valve. The bypass valve bypasses a part of the hydraulic oil around the first heat exchanger at the bypass switching position, and passes a part of the hydraulic oil through the first heat exchanger at the cooling switching position. When cooling of the battery is not required, the bypass switching position can be brought about, for example, by a battery temperature regulator. Correspondingly, when cooling of the battery is required, the cooling switching position can be brought about by the battery temperature regulator.

[0016] In one embodiment, the construction machine is a concrete pump.

[0017] Hereinafter, the present invention will be described in detail with reference to the drawings.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0019] FIG. 1 very schematically shows a construction machine 1000 in the form of an (auto) concrete pump, which comprises a rechargeable battery 1, an electric drive device 2 supplied by the battery 1, a hydraulic circuit 3 in which hydraulic oil 4 circulates, a hydraulic drive device 5 supplied by the hydraulic circuit 3, and a first cooling circuit 6 for cooling the battery 1 and the hydraulic oil 4. In the first cooling circuit 6, a part of the hydraulic oil 4 circulates as a refrigerant. No other or different type of refrigerant is used in addition to the hydraulic oil 4.

[0020] The first cooling circuit 6 has a hydraulic oil pump 7 for generating an adjustable volume flow rate of a part of the hydraulic oil 4. The hydraulic oil pump 7 is, by way of example, a fixed displacement pump driven at an adjustable rotational speed by an electric motor 16 in order to generate an adjustable volume flow rate. The rotational speed of the electric motor 16 is the adjustment variable of a hydraulic oil temperature regulator 11.

[0021] The first cooling circuit 6 further has a first cooler 8 including an associated fan 14 having an adjustable cooling capacity, and a part of the hydraulic oil 4 flows through the first cooler 8. The cooling capacity can be adjusted, for example, by adjusting the fan rotational speed.

[0022] The first cooling circuit 6 further has a first heat exchanger 9 connected downstream of the first cooler 8 and thermally coupled to the battery 1, through which a part of the hydraulic oil 4 flows.

[0023] The construction machine 1000 has a battery temperature regulator 10 designed to adjust the battery temperature measured by a temperature sensor 23 to a predetermined target value, and the adjustment variable of the battery temperature regulator 10 is the cooling capacity of the first cooler 8.

[0024] The construction machine 1000 further has a hydraulic oil temperature regulator 11 designed to adjust the hydraulic oil temperature measured by the temperature sensor 24 to a predetermined target value, and the adjustment amount of the hydraulic oil temperature regulator 11 is a partial volume flow rate of the hydraulic oil 4. The hydraulic oil temperature regulator 11 is parameterized to be slower than the battery temperature regulator 10, for example, by appropriately selecting the regulator time constant and the like.

[0025] The electric drive device 2 is also cooled by the first cooling circuit 6. At this time, for example, a heat exchanger (not shown) is thermally coupled to the electric drive device 2, and a part of the hydraulic oil also flows through this heat exchanger.

[0026] The construction machine further includes power electronics 12 for controlling the electric drive device 2.

[0027] The first cooling circuit 6 has a bypass valve 13. The bypass valve bypasses a part of the hydraulic oil 4 around the first heat exchanger 9 in the bypass switching position, and passes a part of the hydraulic oil 4 through the first heat exchanger 9 in the cooling switching position.

[0028] In the simplest case, the battery temperature regulator 10 can be stopped in the bypass switching position of the bypass valve 13. In this case, the cooling capacity of the first cooler 8 can be adjusted to a fixed value sufficient to cool the hydraulic oil, for example. Further, in this case, it is conceivable that the hydraulic oil temperature regulator 11 affects the cooling capacity of the first cooler 8 as another adjustment amount.

[0029] According to the present invention, it is possible to cool both the electrically driven machine 2, particularly the battery 1 of an electrified concrete pump, and the hydraulic oil 4. The cooling section is designed as a common circuit, particularly to reduce the complexity of the machine system.

[0030] The specified hydraulic oil volume flow rate is conveyed by the hydraulic oil pump 7 from the hydraulic circuit 3 or the hydraulic oil tank 15 through the first (hydraulic oil) cooler 8. The first cooler 8 cools the hydraulic oil 4 to a temperature well below the desired battery temperature. The cooled hydraulic oil 4 is then passed through the battery 1 to cool it. Since the final battery temperature is much lower than the temperature of the hydraulic system, subsequently, the hydraulic oil flow is again directed to the hydraulic system, for example, the tank 15, to cool the hydraulic oil 4.

[0031] The control of the temperature levels of the battery 1 and the hydraulic oil 4 is carried out via, for example, two control circuits. The cooling of the battery 1 is carried out via the first control circuit. The battery temperature is measured and compared with the target temperature. If the temperature is too high or too low, the cooling capacity of the first cooler 8 is correspondingly adapted, for example, by the rotational speed of the fan 14.

[0032] The cooling of the hydraulic oil 4 is carried out via the second control circuit. The temperature of the hydraulic oil 4 in the system / tank 15 is measured and compared with the target temperature. If the temperature is too high or too low, the cooling volume flow rate is correspondingly adapted.

[0033] Since the hydraulic oil 4 at the outlet of the battery 1 has a substantially constant temperature by battery control, the amount of the cooled oil returning to the hydraulic system is controlled by a partial volume flow rate of the hydraulic oil. In that case, the adaptation of the volume flow rate can be carried out, for example, by a variable displacement pump with a fixed rotational speed or, as shown in the figure, by a fixed displacement pump with a variable rotational speed.

[0034] Since the control circuits are coupled to each other via the volume flow rate, it makes sense to synchronize the control circuits. One variant is, for example, to make the hydraulic oil temperature regulation slower than the battery temperature regulation in order to avoid vibrations. As a variant, the entire system can also be equipped with an overall control unit (Regelung) that uses, in addition to the two temperatures, a target quantity as the input quantity and the volume flow rate and the cooling capacity as the output quantities.

[0035] FIG. 2 shows a very schematic view of a construction machine 1000 according to another embodiment. The first cooling circuit 6 additionally has, here as required, a second cooler 17 through which a part of the hydraulic oil 4 flows. The first cooling circuit 6 further has a second heat exchanger 18 connected downstream of the second cooler 17, the second heat exchanger being thermally coupled to the power electronics 12, through which a part of the hydraulic oil 4 flows and which cools the power electronics 12. The second cooler 17 can have an adjustable cooling capacity. Furthermore, a temperature regulator (not shown) can be provided for regulating the temperature of the hydraulic oil 4 flowing out of the second cooler 17 to a target value.

[0036] FIG. 3 shows a very schematic view of a construction machine 1000 according to another embodiment. The construction machine 1000 has a second cooling circuit 19 for cooling the power electronics 12, in which another part of the hydraulic oil 4 circulates as a refrigerant. The second cooling circuit 19 has another hydraulic oil pump 20, a third cooler 21, and a second heat exchanger 22 connected downstream and thermally coupled to the power electronics 12, through which another part of the hydraulic oil 4 flows. The temperature of the power electronics 12 can be regulated, for example, by a relevant temperature regulator which uses, as the regulation quantity, for example, the delivery capacity of another hydraulic oil pump 20 and / or the cooling capacity of the third cooler 21.

[0037] According to the present invention, since there is no separate first cooling circuit for the battery, the number of physical components required for cooling can be reduced. Thereby, the physical system structure also becomes simpler. Furthermore, since only hydraulic oil is used as a whole, no additional cooling medium is required.

Claims

1. A construction machine (1000), comprising: a battery (1); at least one electric drive device (2) powered by the battery (1); a hydraulic circuit (3) through which hydraulic oil (4) circulates; at least one hydraulic drive device (5) supplied by the hydraulic circuit (3); and a first cooling circuit (6) for cooling the battery (1) and the hydraulic oil (4), wherein a part of the hydraulic oil (4) circulates as a refrigerant in the first cooling circuit (6).

2. The first cooling circuit (6) includes: a hydraulic oil pump (7) for generating an adjustable volume flow rate of a part of the hydraulic oil (4); a first cooler (8) having an adjustable cooling capacity through which a part of the hydraulic oil (4) flows; and a first heat exchanger (9) connected downstream of the first cooler (8) and thermally coupled to the battery (1), through which a part of the hydraulic oil (4) flows. The construction machine (1000) according to claim 1, characterized in that.

3. The construction machine (1000) includes: a battery temperature regulator (10) designed to adjust the battery temperature to a predetermined target value, wherein the adjustment amount of the battery temperature regulator (10) is the cooling capacity of the first cooler (8).

4. The construction machine (1000) includes: a hydraulic oil temperature regulator (11) designed to adjust the hydraulic oil temperature to a predetermined target value, wherein the adjustment amount of the hydraulic oil temperature regulator (11) is the volume flow rate of a part of the hydraulic oil (4).

5. The hydraulic oil temperature regulator (11) is parameterized to be slower than the battery temperature regulator (10). The construction machine (1000) according to claims 4 and 5, characterized in that.

6. The at least one electric drive device (2) is cooled by the first cooling circuit (6). The construction machine (1000) according to any one of claims 1 to 5, characterized in that.

7. The construction machine includes power electronics (12) for controlling the at least one electric drive device (2), and the power electronics (12) is cooled by the hydraulic oil (4). The construction machine (1000) according to any one of claims 1 to 6, characterized in that.

8. The first cooling circuit (6) A second cooler (17) through which a part of the hydraulic oil (4) flows; Connected downstream of the second cooler (17) and thermally coupled to the power electronics (12), a second heat exchanger (18) through which a part of the hydraulic oil (4) flows; Having The construction machine (1000) according to claim 7, characterized in that.

9. The construction machine (1000) includes a second cooling circuit (19) for cooling the power electronics (12), and another part of the hydraulic oil (4) circulates as a refrigerant in the second cooling circuit (19) The construction machine (1000) according to claim 7, characterized in that.

10. The first cooling circuit (6) has a bypass valve (13), and the bypass valve bypasses a part of the hydraulic oil (4) around the first heat exchanger (9) in the bypass switching position, and in the cooling switching position, passes a part of the hydraulic oil (4) through the first heat exchanger (9) The construction machine (1000) according to any one of claims 2 to 9, characterized in that.

11. The construction machine (1000) is a concrete pump The construction machine (1000) according to any one of claims 1 to 10, characterized in that.

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