Cooling device

Abstract

To control the amount of oil supplied to a catch tank.SOLUTION: A cooling device is mounted on a series hybrid vehicle including an engine, a motor for power generation, a gear pair for transmitting the power of the engine to the motor for power generation, a catch tank for storing oil scraped up by the gear pair, and a control device for controlling the engine, and cools the motor for power generation using oil stored in the catch tank, wherein the gear pair is arranged at a position where an input gear on an engine side is immersed in the oil in rotation stop, the input shaft rotated integrally with the input gear is arranged at a position lower than the rotary shaft of the motor, and when the amount of the oil stored in the catch tank is small, the control device changes the operation point of the engine so that the engine rotation number is increased on a power line where the engine rotation number in which the output of the engine becomes constant and an engine torque are regulated.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a cooling device.

Background Art

[0002] Patent Document 1 discloses an oil supply device that scoops up oil stored in a transaxle case by the rotation of a differential ring gear and supplies the scooped-up oil to a catch tank by the rotation of a gear pair provided upstream of the differential ring gear.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, with the configuration of Patent Document 1, the oil supply amount that can be supplied to the catch tank cannot be arbitrarily controlled. With the configuration of Patent Document 1, since the oil is scooped up by the rotation of the differential ring gear, a limit occurs in the amount of oil scooped up when the oil supply amount becomes more than necessary.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a cooling device capable of controlling the amount of oil supplied to a catch tank.

Means for Solving the Problems

[0006] The present invention is mounted on a series hybrid vehicle including an engine, a power generation motor, a gear pair that transmits the power of the engine to the power generation motor, a catch tank that stores oil scooped up by the gear pair, and a control device that controls the engine, and is a cooling device that cools the power generation motor using the oil stored in the catch tank. The gear pair is arranged such that the input gear on the engine side is immersed in oil when the rotation stops, and the input shaft that rotates integrally with the input gear is arranged at a position lower than the rotation shaft of the motor. The control device changes the operating point of the engine so that the engine speed increases on an isopower line that defines an engine speed and engine torque at which the output of the engine becomes constant when the amount of oil stored in the catch tank is small.

Effects of the Invention

[0007] In the present invention, in a series hybrid vehicle, since the operating point of the engine can be changed while keeping the engine output constant, by increasing the engine speed while keeping the output to the power generation motor constant, the rotation speed of the input shaft can be increased, and the amount of oil scooped up can be increased. Thereby, the amount of oil supplied to the catch tank can be controlled.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] Hereinafter, with reference to the drawings, the cooling device in the embodiment of the present invention will be specifically described. Note that the present invention is not limited to the embodiments described below.

[0010] FIG. 1 is a diagram schematically showing the cooling device in the embodiment. The cooling device 1 is a cooling device mounted on a vehicle Ve including an engine 2 and a power generation motor 3, and is configured to cool the power generation motor 3 with oil 10. The oil 10 is a liquid for cooling the power generation motor 3 and is composed of insulating oil.

[0011] The vehicle Ve is a series hybrid vehicle that generates electricity with the power generation motor 3 using the power output from the engine 2 and drives a driving motor using the generated electricity. This vehicle Ve includes a gear pair 4 that transmits the power of the engine 2 to the power generation motor 3, a case 5 that houses the gear pair 4 and the power generation motor 3, a catch tank 6 provided on the upper part of the case 5, and a control device 7 that controls the engine 2.

[0012] The power generation motor 3 includes a rotor 31, a stator 32, and a rotor shaft 33. The rotor 31 and the stator 32 are housed inside a motor chamber 52 located on one side with respect to a partition wall 51 in the case 5. The rotor shaft 33 is a rotating shaft that rotates integrally with the rotor 31, and extends from the motor chamber 52 through the partition wall 51 into the gear chamber 53 inside the case 5.

[0013] The gear pair 4 includes a drive gear 41 that is an input gear on the engine side and a driven gear 42 that meshes with the drive gear 41. This gear pair 4 is housed inside a gear chamber 53 located on the other side with respect to the partition wall 51 in the case 5.

[0014] The drive gear 41 is a gear with a larger diameter than the driven gear 42 and rotates integrally with the input shaft 21. The driven gear 42 is a gear with a smaller diameter than the drive gear 41 and rotates integrally with the rotor shaft 33. Therefore, when the power of the input shaft 21 is transmitted to the rotor shaft 33 via the gear pair 4, the rotational speed of the drive gear 41 is lower than the rotational speed of the driven gear 42.

[0015] The input shaft 21 extends to the outside of the case 5 and is connected to the crankshaft of the engine 2 via the damper 22. When the engine 2 is driven and the crankshaft rotates, the input shaft 21 and the drive gear 41 rotate integrally.

[0016] The case 5 houses the power generation motor 3, the gear pair 4, and the oil 10. This case 5 has a partition wall 51 inside and has a structure in which the motor chamber 52 and the gear chamber 53 are partitioned via the partition wall 51. On the gear chamber 53 side inside this case 5, the oil 10 scraped up by the gear pair 4 is supplied to the catch tank 6. The oil 10 supplied to the catch tank 6 in the gear chamber 53 of the case 5 flows to the motor chamber 52 side of the case 5 and is supplied to the upper part of the power generation motor 3 and used for cooling the power generation motor 3.

[0017] The catch tank 6 extends into the gear chamber 53 and the motor chamber 52 so as to penetrate the partition wall 51 at the upper part inside the case 5. The catch tank 6 includes a first part 61 that receives the oil 10 at the upper part of the case inside the gear chamber 53, a second part 62 that flows the oil 10 received at the first part 61 from the gear chamber 53 side to the motor chamber 52 side, and a third part 63 that supplies the oil 10 that has flowed through the second part 62 to the upper part of the power generation motor 3 inside the motor chamber 52. As shown in FIG. 2, in the vertical direction of the case 5, the catch tank 6 is arranged above the power generation motor 3.

[0018] Here, with reference to FIGS. 1 and 2, the vertical arrangement inside the case 5 will be described.

[0019] In the vertical direction, the driving gear 41, which is a gear with a low rotational speed in the gear pair 4, is arranged at the lowest position. The driven gear 42, which is a gear with a high rotational speed, is arranged at a position higher than the driving gear 41 with a low rotational speed. That is, in the vertical direction of the two-shaft arrangement parallel in the case 5, the input shaft 21, which is a shaft with a low rotational speed, is arranged at the lowest position. The rotor shaft 33 with a high rotational speed is arranged at a position higher than the input shaft 21, which is a shaft with a low rotational speed.

[0020] Also, in the static state of the gear pair 4 in the case 5, only the driving gear 41, which is the gear with the lowest rotational speed during rotation, is immersed in the oil 10. That is, the oil level 11 of the oil 10 stored in the lower part of the case 5 is at a position higher than the lowermost part of the driving gear 41. Further, in the static state of the two parallel shafts in the case 5, only the input shaft 21, which is the shaft with the lowest rotational speed during rotation, is immersed in the oil 10. That is, the oil level 11 of the oil 10 stored in the lower part of the case 5 is at a position higher than the lowermost part of the input shaft 21.

[0021] Therefore, the oil 10 scraped up by the driving gear 41 and the input shaft 21 is supplied to the catch tank 6 located above the driving gear 41 and is also supplied to the driven gear 42. The oil 10 supplied from the driving gear 41 to the driven gear 42 scatters upward in the case 5 due to the rotation of the driven gear 42 and is supplied to the catch tank 6 located above the driven gear 42.

[0022] Note that the difference in the vertical arrangement in the case 5 represents whether the rotational center position of the rotating member is at a relatively low position or a relatively high position. That is, even when a part of the driving gear 41 is arranged at a vertical position overlapping a part of the driven gear 42, if the position of the rotation center O1 of the driving gear 41 is lower than the position of the rotation center O2 of the driven gear 42, it is possible to express that the driving gear 41 is arranged at a lower position than the driven gear 42. This relationship is the same for the input shaft 21 and the rotor shaft 33 of the two parallel shafts.

[0023] The control device 7 is an electronic control device that controls the engine 2. Based on signals input from various sensors, the control device 7 executes control to adjust the amount of oil supplied to the catch tank 6. Specifically, when the control device 7 determines that the amount of oil stored in the catch tank 6 is small, it executes control to change the engine speed and engine torque on the constant power line.

[0024] For example, a signal indicating the temperature measured by the oil temperature sensor of the power generation motor 3 is input to the control device 7. When the control device 7 determines that the temperature exceeds the threshold value, it determines that cooling of the power generation motor 3 is necessary and that the amount of oil stored in the catch tank 6 is small. Alternatively, a signal indicating the oil level height detected by a sensor capable of measuring the oil level disposed in the catch tank 6 is input to the control device 7. When the control device 7 determines that the oil level height in the catch tank 6 is below a predetermined threshold value, it determines that the amount of oil stored in the catch tank 6 is small. Or, when the control device 7 determines that pre-cooling of the power generation motor 3 is necessary by means of prediction or the like, it determines that the amount of oil stored in the catch tank 6 is small.

[0025] Since the vehicle Ve is a series hybrid vehicle, the power of the engine 2 is not transmitted to the tire shaft (axle), so the operating point of the engine 2 can be arbitrarily changed. The operating point of the engine 2 is defined by the engine torque and the engine speed. The control device 7 can change the operating point of the engine 2 on the constant power line where the output of the engine 2 is constant.

[0026] Therefore, when the control device 7 determines that the amount of oil stored in the catch tank 6 is low, as shown in FIG. 3, it changes the operating point from the first operating point P1 to the second operating point P2 so that the engine speed N increases on the equal power line. The first operating point P1 is an operating point defined by the engine speed N1 and the engine torque T1. The second operating point P2 is an operating point defined by the engine speed N2 and the engine torque T2. The engine speed N1 is lower than the engine speed N2. The engine torque T1 is higher than the engine torque T2. Thus, by changing the operating point from the first operating point P1 to the second operating point P2 on the equal power line, without changing the power generation output required from the vehicle Ve, the rotational speed of the input shaft 21 can be increased, and the amount of oil 10 scooped up can be increased.

[0027] FIG. 4 is a flowchart showing a control flow when controlling the amount of oil stored in the catch tank. The control shown in FIG. 4 is repeatedly executed by the control device 7.

[0028] The control device 7 determines whether it is necessary to increase the amount of oil in the catch tank 6 (step S1). In step S1, it is determined whether the amount of oil stored in the catch tank 6 is low. For example, it is determined whether the temperature detected by the oil temperature sensor of the power generation motor 3 exceeds a threshold value. Alternatively, it is determined whether the oil level detected by a sensor that measures the oil level in the catch tank 6 is below a predetermined threshold value. Or, it is determined whether pre-cooling of the power generation motor 3 by pre-reading or the like is necessary.

[0029] When it is determined that there is no need to increase the amount of oil in the catch tank 6 (step S1: No), this control routine ends.

[0030] When it is determined that it is necessary to increase the amount of oil in the catch tank 6 (step S1: Yes), the control device 7 determines whether it is possible to increase the rotational speed of the input shaft 21 (step S2). In step S2, it is determined whether it is possible to increase the rotational speed of the input shaft 21 (engine 2) due to external vehicle noise or the like. For example, if it is determined that the external vehicle noise is high, the determination in step S2 is negative.

[0031] When it is determined that it is possible to increase the rotational speed of the input shaft 21 (step S2: Yes), the control device 7 changes the operating point of the engine 2 so that the engine speed increases on the equal power line (step S3). In step S3, the power generation amount of the power generation motor 3 is not changed, and the rotational speed and torque of the engine 2 are changed on the equal power line. For example, the operating point is changed to the high rotational speed side on the equal power line, such as from the first operating point P1 to the second operating point P2 shown in FIG. 3. When the process of step S3 is performed, this control routine returns to step S1.

[0032] When it is determined that it is not possible to increase the rotational speed of the input shaft 21 (step S2: No), this control routine proceeds to output limitation.

[0033] As described above, according to the embodiment, since only the drive gear 41 with the lowest rotational speed among the gear pairs 4 touches the oil 10, it is possible to minimize the loss (agitation loss) due to the shearing force between the oil 10 and the drive gear 41.

[0034] Also, without changing the power generation output required from the vehicle Ve, the rotational speed of the input shaft 21 can be increased, and the amount of oil 10 being scooped up can be increased. Thereby, the cooling effect of the power generation motor 3 can be ensured. Further, in this case, the fact that there is no change in the power generation output can be regarded as the heat generation amount of the power generation motor 3 not increasing. Strictly speaking, although it varies depending on the characteristics of the power generation motor 3, the losses of the power generation motor 3 include copper loss and iron loss. The copper loss depends on torque, and the iron loss depends on rotational speed. Therefore, when the torque is reduced and the rotational speed is increased on an equal power line, the heat generation amount of the power generation motor 3 is reduced.

Explanation of Signs

[0035] 1 Cooling device 2 Engine 3 Power generation motor 4 Gear pair 5 Case 6 Catch tank 7 Control device 10 Oil 11 Oil level 41 Driving gear 42 Driven gear 51 Partition wall 52 Motor chamber 53 Gear chamber 61 First part 62 Second part 63 Third part Ve Vehicle

Claims

【Claim 1】 An engine, a power generation motor, a gear pair for transmitting the power of the engine to the power generation motor, a catch tank for storing oil scooped up by the gear pair, and a control device for controlling the engine, mounted on a series hybrid vehicle, A cooling device for cooling the power generation motor using the oil stored in the catch tank, The gear pair is arranged such that the input gear on the engine side is immersed in oil when the rotation stops, The input shaft that rotates integrally with the input gear is arranged at a position lower than the rotation shaft of the motor, When the amount of oil stored in the catch tank is low, the control device changes the operating point of the engine so that the engine speed increases on an isopower line that defines the engine speed and engine torque at which the output of the engine is constant. A cooling device characterized by the above.

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