JP2010104130A - System for cooling driving system of hybrid construction equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a cooling system which rationally cools an electric motor and a driver controller in hybrid construction equipment. <P>SOLUTION: The system for cooling a driving system of hybrid construction equipment includes a battery which is charged with electric power generated by a generator, and an electric motor which is driven by the driver controller with the electric power of the battery. A cooling channel that cools a generator/motor 36 in a cooling liquid circulating channel is configured with a first annular channel 70D formed on the side where the cooling liquid flows in, a second annular channel 70E formed on the side where the cooling liquid flows out, a plurality of connecting channels 70F which are provided between the first and second annular channels 70D, 70E along the axial direction to make the cooling liquid flow from the first annular channel 70D side to the second annular channel 70E side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cooling system for a drive device of a so-called hybrid construction machine.

  Patent Document 1 includes an electric motor such as an engine, a generator, a battery, a driver controller, a boom generator motor, a turning generator motor, and a traveling generator motor, and can always operate the engine in an efficient state. In addition, a drive device for a hybrid construction machine has been proposed that saves energy, reduces noise, and reduces exhaust gas.

JP 2002-242234 A

  In the drive device of the hybrid construction machine, in addition to an engine attached to a dedicated radiator or the like, a motor (including a generator motor), a driver controller such as an inverter or a converter for driving the motor, etc. Are subject to “cooling”. However, if compared, the driver controller rather than the electric motor has a higher cooling requirement.

  Here, many cooling structures for cooling the electric motor have been proposed. However, these cooling structures are intended to sufficiently (effectively) cool the electric motor alone. Therefore, the pressure loss is large. Therefore, if each motor of the construction machine is cooled by such a cooling structure for cooling the motor, as a result, there is a risk of adversely affecting the cooling of the driver controller that requires a higher degree of cooling. This is true even if the driver controller is arranged upstream of the cooling circuit from the electric motor.

  Providing a sufficiently large pump to avoid this problem and forming a coolant circulation path with a large processing heat capacity leads to an increase in cost and weight, and greatly reduces the energy saving that is the basic principle of hybrid construction machinery. It is.

  The present invention has been made to solve such a conventional problem, and in particular, in a hybrid construction machine, the cooling of the drive device that can more efficiently cool the electric motor and the driver controller. The challenge is to provide a system.

  The present invention relates to a cooling system for a drive device of a hybrid construction machine provided with an electric motor charged with electric power generated by a generator and driven by a driver controller using the electric power of the battery. After cooling the driver controller and the electric motor from the pump, a cooling fluid circulation path is provided for exchanging heat with a radiator and circulating to the pump, and a cooling flow path for cooling the electric motor in the cooling fluid circulation path, The electric motor between a first annular flow path formed on the cooling liquid inflow side, a second annular flow path formed on the cooling liquid outflow side, and the first and second annular flow paths. The above-mentioned problem is solved by comprising a plurality of connecting passages along the axial direction of the first and second connecting passages through which the coolant flows from the first annular passage side to the second annular passage side. It is what.

  In the present invention, in the hybrid construction machine, in particular, the electric motor includes: “a first annular flow path formed on the cooling liquid inflow side; a second annular flow path formed on the cooling liquid outflow side; A plurality of connecting passages that are provided between the first and second annular passages along the axial direction and that flow cooling liquid from the first annular passage side to the second annular passage side; Cooling is performed with a “configured cooling structure”. As a result, the pressure loss in the electric motor can be reduced as much as possible, and as a result, the driver controller can be cooled well, and the entire drive device of the hybrid construction machine can be reasonably cooled without increasing cost and weight. be able to.

  In the hybrid construction machine, particularly the driver controller can be cooled well, and as a result, a cooling system capable of rationally cooling the entire drive device can be constructed.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 4 shows an overall schematic configuration of a drive device of a hybrid hydraulic excavator (construction machine) to which an example of the embodiment of the present invention is applied.

  In the drive device 10 of this hydraulic excavator (not shown), a hydraulic pump 32 and a generator motor 30 are coupled to an engine 31 in parallel. A known hydraulic oil tank 43 and a hydraulic controller 33 are connected to the hydraulic pump 32 to form an open circuit capable of driving the hydraulic cylinder 34 for driving the arm and the hydraulic cylinder 35 for driving the bucket. On the other hand, the generator motor 30 supplies power (AC) generated when operating as a generator to the driver controller 24.

  The driver controller 24 includes an AC-DC converter 50, a plurality of inverters 52 to 56, converters 51 and 57 having a DC-DC converter, and a control unit 22. The driver controller 24 performs DC-AC conversion control, DC-DC conversion control, and AC-DC conversion control under the control of the overall controller 23. The controller 22 of the driver controller 24 controls the AC-DC converter 50 and the inverters 52 to 56 based on a control command from the overall controller 23, and generates a boom generator motor 36, a swing generator motor 37, a traveling power generator. While controlling the electric power supplied to the electric motors 38 and 39, the regenerative electric power of each generator motor 36-39 is controlled.

  The overall controller 23 receives operation outputs from the boom lever 16, arm lever 17, bucket lever 18, turning lever 19, and travel lever 20 and outputs from various sensors (not shown), and sends them to the driver controller 24 and the power controller 40. Send a control signal. The power controller 40 controls the driving mode of the hydraulic pump 32 and the generator motor 30.

  The boom generator motor 36 is connected to fixed displacement hydraulic pump motors 27, 28 and drives a boom (not shown) via a boom cylinder 29. On the other hand, the swing generator motor 37 and the travel generator motors 38 and 39 are configured to directly drive a swing mechanism and a travel mechanism (not shown). In the figure, reference numeral 41 denotes a battery, and 42 denotes a capacitor. The battery 41 accumulates electric power regenerated from each of the generator motors 30 and 36 to 39, and supplies necessary electric power when the generator motors 30 and 36 to 39 are driven as motors.

  In the cooling system according to this embodiment, a pump 72 and a radiator 74 are provided on the coolant circulation path 70. The coolant circulation path 70 is directed to the driver controller 24 via the cooling flow path 70A, and after cooling the driver controller 24, the generator motor 30 is first cooled via the cooling flow path 70B1 (70B1 → * 1). Next, it goes to the generator motors 36 and 37 via the cooling flow path 70B2 (* 1 → 70B2), further passes through the traveling generator motors 38 and 39, reaches the radiator 74 via the cooling flow path 70C, and returns to the pump 72. It is arranged like this. The coolant is circulated to the pump 72 in a state where it is cooled again by heat exchange in the radiator 74. This cooling system is configured as a cooling system of a different system from the engine cooling system (not shown). However, both systems may be combined if necessary.

  Since the coolant in the coolant circulation path 70 needs to cool as many as four generator motors 36 to 39 after the driver controller 24 is cooled, excessive pressure loss occurs in each of the generator motors 36 to 39. A cooling structure as shown in FIGS. 1 to 3 is employed for the generator motors 36 to 39 so that (pressure loss) does not occur. The boom generator motor 36 will be taken as an example, and the cooling structure will be described as a representative. For the other generator motors 30 and 37 to 39, the cooling structure itself basically has the same configuration.

  The boom generator motor 36 (and the generator motors 30, 37 to 39) is cooled by the first and second annular flow paths 70D and 70E and the connection flow path 70F, which are part of the coolant circulation path 70. That is, the cooling flow path of the boom generator motor 36 includes a first annular flow path 70D formed on the cooling liquid inflow side, a second annular flow path 70E formed on the cooling liquid outflow side, 1 and a connection channel 70F that is provided in plural along the axial direction between the second annular channels 70D and 70E and allows the coolant to flow from the first annular channel 70D side to the second annular channel 70E side. It is mainly composed.

  Since the first annular flow path 70D into which the coolant flows is located on the most upstream side in the cooling flow path of the boom generator motor 36, higher cooling performance is required in the boom generator motor 36. It is preferable to arrange on the side. In this embodiment, the first annular channel 70 </ b> D is disposed on the side where a sensor such as a resolver (or encoder) 86 is provided. The first annular flow path 70 </ b> D is formed in a ring shape around the inside of the vicinity of the end 88 </ b> A of the motor casing 88. As shown in FIGS. 2 and 3, the first annular flow path 70D is connected to an inflow port 90 formed of a right angle elbow, and the coolant is supplied from a substantially tangential direction of the first annular flow path 70D. It is configured to flow in.

  The second annular channel 70E is formed in a ring shape around the inside of the motor casing 88 in the vicinity of the axially opposite end 88B of the first annular channel 70D. As shown in FIGS. 2 and 3, the second annular flow path 70E is connected to an outlet 92 formed by a right angle elbow, and the coolant flows out from a substantially tangential direction of the second annular flow path 70E. It is configured to be.

  A plurality (twelve in this embodiment) of connecting flow paths 70F are arranged along the axial direction between the first and second annular flow paths 70D and 70E. In this embodiment, the cross section is formed by a circular pipe for the purpose of reducing manufacturing ease and pressure loss as much as possible. However, in order to increase cooling efficiency, an elliptical or flattened cross section is used. You may make it form with the pipe which has.

  As shown in FIGS. 1 and 3, a total of four through holes 93 to 96 through which wiring for driving the boom generator motor 36 passes (a U-phase through hole 93, between the connection flow paths 70 </ b> F). A total of four V-phase through-holes 94, W-phase through-holes 95, and thermistor through-holes 96 are formed.

  Next, the operation of this cooling system will be described.

  When the hydraulic excavator is operated, the generator motor 30, the boom generator motor 36, the swing generator motor 37, or the traveling generator motors 38 and 39 generate corresponding heat. The driver controller 24 for controlling the generator motors 30 and 36 to 39 also generates heat. These devices are cooled as follows.

  When the pump 72 rotates, the coolant in the coolant circulation path 70 reaches the driver controller 24 via the cooling path 70A, and the driver controller 24 is first cooled. Thereafter, the cooling liquid reaches the inlet 90 of the first annular channel 70D of the generator motor 30 through the cooling channel 70B1, and flows into the first annular channel 70D from a substantially tangential direction of the first annular channel 70D. To do. Therefore, the pressure loss at the time of inflow is small, and the coolant can easily spread over the entire first annular channel 70D (the entire circumference). As a result, the coolant flows from the twelve connecting flow paths 70F almost uniformly toward the second annular flow path 70E. In the second annular channel 70E, since the outlet 92 is disposed in the tangential direction of the second annular channel 70E, the coolant that has reached the second annular channel 70E can flow out smoothly, The pressure loss at the outflow is also small.

  Structure in which the inflow of the first annular channel 70D, the progress of the coolant through the connection channel 70F, and the outflow from the second annular channel 70E obstruct the coolant flow such as meandering, damming, dead end, etc. Since there is almost no structure that keeps the coolant in the vicinity of the equipment to be cooled for a long time, the pressure loss from inflow to outflow is extremely small. Moreover, the first and second annular flow paths 70D and 70E are arranged so as to surround the entire periphery of the boom generator motor 36 evenly, coupled with the fact that the first and second annular channels 70D and 70E make a round around the end portion of the boom generator motor 36. Therefore, the cooling efficiency is high.

  The coolant that has flowed out of the second annular channel 70E of the generator motor 30 is sent to the boom generator motor 36 via the cooling channel 70B2, and the boom generator motor 36 is cooled by the same action (with a small pressure loss). Further, it is sent to the swivel generator motor 37 and the two traveling generator motors 38 and 39, and here, cooling is performed by the same action (with a small pressure loss). Therefore, the traveling generator motor 39 located on the most downstream side of the coolant circulation path 70 can be cooled well, and the pressure loss of the coolant circulation path 70 as a whole is reduced. As a result, the driver controller 24 Cooling can be performed sufficiently satisfactorily.

  The coolant that has flowed out of the generator motor 39 is sent to the radiator 74 via the cooling flow path 70C, where heat is exchanged to lower the temperature, and the driver controller 24 again at a predetermined pressure by the pump 72. To be sent to.

  Here, in general, when a cooling flow path for cooling an electric motor is formed in a casing, there are many examples in which it is extremely difficult to secure a wiring space that needs to penetrate the inside and outside of the casing. Since the connecting flow path 70F according to the embodiment is linear and there is a gap between each one, a through hole (wiring space) through which wiring for driving the boom generator motor 36 is made using this gap. ) 92 to 96 can be secured. Therefore, it is not necessary to expand the axial space only to secure the wiring space, which contributes to shortening the axial length of the boom generator motor 36 (similarly, the generator motors 37 to 39).

  In the above embodiment, an example in which twelve connection channels 70F having a circular cross section are formed is shown. However, in the present invention, the shape and number of the connection channels are not particularly limited. A connecting channel having a circular cross section has less pressure loss than a non-circular connecting channel. Since the noncircular connecting flow path has a large surface area with respect to the motor (if it is the same number), more efficient cooling can be performed. As the number of connection channels increases (if the cross-sectional area of each connection channel is secured to some extent), the pressure loss decreases and the cooling efficiency tends to increase. Note that the connecting flow paths are not necessarily arranged at equal intervals in the circumferential direction.

  Moreover, in the said embodiment, although all the components and all the electric motors of the driver control apparatus were cooled, you may make only a part of the components of a driver controller, or a part of an electric motor into the object of cooling.

  In the above embodiment, all the cooling objects are cooled by only one coolant circulation path. However, a plurality of coolant circulation paths are provided, and a part of the driver is provided in each coolant circulation path. In addition, only a part of the plurality of electric motors may be cooled. The order of cooling may also be, for example, the order of electric motor → driver controller.

  Further, in the above embodiment, the cooling liquid flows into or out of the annular channel from the tangential direction of the annular channel for both the inlet and the outlet. The inflow port and / or the outflow port may be configured to flow in or out from a direction other than the tangential direction of the annular flow path.

  In particular, a very good effect can be obtained in a cooling system for a drive device of a hybrid construction machine having important cooling equipment such as a driver controller in addition to an electric motor.

The front view which shows the coolant circulation path of the boom generator motor in the cooling system of the drive device of the hybrid construction machine which concerns on an example of embodiment of this invention. Front view of the upper part of the boom generator motor Sectional view along arrow III-III in FIG. Overall schematic configuration diagram of cooling system for driving device of hybrid construction machine

Explanation of symbols

DESCRIPTION OF SYMBOLS 16-20 ... Operation lever 22 ... Control part 23 ... General controller 24 ... Driver controller 30 ... Generator motor 32 ... Hydraulic pump 36 ... Boom generator motor 37 ... Swing generator motor 38, 39 ... Traveling generator motor 50, 51, 57 ... Converters 52 to 56 ... Inverter 70 ... Coolant circulation path 70A to 70C ... Cooling flow path 70D ... First annular flow path 70E ... Second annular flow path 70F ... Connection flow path 72 ... Pump 74 ... Radiator 86 ... Resolver 88 ... Motor casing 90 ... Inlet 92 ... Outlet 93-96 ... Through hole

Claims (3)

A cooling system for a drive device of a hybrid construction machine comprising an electric motor charged with electric power generated by a generator and driven by a driver controller using the electric power of the battery,
After cooling the driver controller and the electric motor by sending out the cooling liquid from the pump, it is provided with a cooling liquid circulation path for exchanging heat with a radiator and circulating to the pump,
The cooling flow path for cooling the electric motor in the cooling liquid circulation path includes a first annular flow path formed on the side into which the cooling liquid flows and a second annular flow path formed on the side from which the cooling liquid flows out. And a plurality of the first and second annular flow paths are provided along the axial direction of the electric motor, and a coolant is allowed to flow from the first annular flow path side to the second annular flow path side. A cooling system for a drive device of a hybrid construction machine, characterized by comprising a connecting flow path. In claim 1,
At least one of the coolant flowing into the first annular channel and the coolant flowing out from the second annular channel is substantially tangential to the first annular channel or the second annular channel. A cooling system for a drive device of a hybrid construction machine, wherein the cooling system is flowed into or out of each annular flow path. In claim 1 or 2,
A cooling system for a drive device of a hybrid construction machine, wherein a through-hole through which wiring for driving the electric motor is passed is formed between the connection flow paths.

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