Power generator

Abstract

To address a problem of a convention power generator in which, when continuous operation is performed, generated power is sometimes restricted due to temperature increase in a coil end or a magnet.SOLUTION: In a power generator J installed in an electric vehicle, a rotor 3 and a stator 4 are housed in a housing 2 having a water jacket 1. The housing 2 includes a first air chamber 5 on one side of the stator 4, a second air chamber 6 on the other side, an air inlet 7, and an air outlet 8. The rotor 3 includes an internal air path 9 and a fan 10. A temperature sensor 11 that detects the temperature of the inside of the housing 2, and a control device 12 that controls the rotation speed of the rotor 3 on the basis of the temperature detected by the temperature sensor 11 are provided. The rotation speed of the fan 10 for cooling air can be varied according to the temperature state, whereby the temperature increase can be suppressed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a generator mounted on a vehicle such as an electric vehicle. [Background technology]

[0002] An example of a conventional generator is described in Patent Document 1. Patent Document 1 describes a totally enclosed main motor for a vehicle that includes a stator core, a rotor core arranged on the inner periphery of the stator core, a rotor shaft to which the rotor core is attached, a ventilation passage formed on the outer periphery of the stator core, and a ventilation fan provided on the rotor shaft, and that has a structure in which air introduced from the outside is circulated through the ventilation passage and released to the outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-220417 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a vehicle equipped with a generator equivalent to the electric motor described above, the cooling capacity of the stator coil ends and the rotor magnets is constant regardless of the load on the generator, so when the generator is operated continuously, the temperature of the coil ends and magnets may rise, limiting the generated power, which may result in the driver feeling a lack of power performance.

[0005] The present invention has been made in consideration of the above-mentioned conventional situation, and aims to provide a generator in which the stator is liquid-cooled and the rotor is air-cooled, and the rotation speed of the air-cooling fan is variable according to the temperature state as well as the power generation output required for the original function of the generator, thereby preventing overheating. [Means for solving the problem]

[0006] The generator according to the present invention is mounted on a vehicle and has both liquid-cooling and air-cooling functions. This generator accommodates a rotor on the central side and a stator arranged on the outer periphery of the rotor in a housing having a water jacket. The housing includes a first air chamber formed on one axial side of the stator, a second air chamber formed on the other axial side of the stator, an air inlet communicating with the first air chamber from the outside, and an air outlet communicating from the second air chamber to the outside. The rotor also includes an internal air passage that communicates the first air chamber with the second air chamber, and a fan that is arranged on at least one side of the first air chamber side and the second air chamber side and forms an air flow from the air inlet through the internal air passage to the air outlet. The generator is characterized by including a temperature sensor that detects the temperature of at least the first air chamber in the housing, and a control device that controls the rotation speed of the rotor and the fan based on the temperature detected by the temperature sensor. Effect of the Invention

[0007] By adopting the above-mentioned configuration, the generator according to the present invention has a liquid-cooled stator and an air-cooled rotor, and the rotation speed of the air-cooling fan can be varied according to the temperature state to prevent overheating. As a result, in a vehicle equipped with the generator, even if the generator is operated continuously, it is possible to eliminate a situation in which the driver feels that the power performance is insufficient. [Brief description of the drawings]

[0008] [Figure 1] 1 is an explanatory cross-sectional view showing a first embodiment of a generator according to the present invention; [Diagram 2] 2 is a flowchart illustrating a processing step of a control device in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First Embodiment The generator J shown in FIG. 1 is mounted on an electric vehicle and has both liquid-cooled and air-cooled functions. A central rotor 3 and a stator 4 arranged on the outer periphery of the rotor 3 are housed within a housing 2 having a water jacket 1.

[0010] The rotor 3 includes a rotor shaft 3A that rotatably passes through the housing 2, and a rotor core 3B that is attached to the outer periphery of the rotor shaft 3A. Although not shown in detail, the stator 4 has a well-known structure in which a coil is wound around a stator core fixed to the inner surface of the housing 2. An output shaft of a generator engine (not shown) is connected to the rotor shaft 3A.

[0011] The housing 2 is provided with a first air chamber 5 formed in a coil end on one axial side (the right side in FIG. 2) of the stator 4, a second air chamber 6 formed in a coil end on the other axial side of the stator 4, an air inlet 7 communicating with the first air chamber 5 from the outside, and an air outlet 8 communicating from the second air chamber 6 to the outside. The first air chamber 5 and the second air chamber 6 are both spaces that are continuous in the circumferential direction with the rotor 3 at the center.

[0012] The rotor 3 has an internal air passage 9 formed along the axial direction of the rotor core 3B, which connects the first air chamber 5 and the second air chamber 6. The internal air passages 9 are formed at a plurality of locations in the circumferential direction of the rotor core 3B. The rotor 3 also has a fan 10 disposed on at least one of the first air chamber 5 side and the second air chamber 6 side, which forms an air flow from the air inlet 7 through the internal air passage 9 to the air outlet 8. In the illustrated example, the fan 10 is disposed on the second air chamber 6 side, but it is also possible to provide the fan 10 on the first air chamber 5 side or on both sides.

[0013] In the generator J, a temperature sensor 11 for detecting the temperature in the first air chamber 5 of the housing 2 is provided in the first air chamber 5, and an opening adjustment device 13 for changing the opening (opening area) of the air inlet 7 is provided in the first air chamber 5 of the housing 2. The temperature sensor 11 is provided in the vicinity of the coil end. A valve mechanism, for example, can be used as the opening adjustment device 13.

[0014] The generator J also includes a control device 12 that controls the rotation speed of the rotor 3 based on the temperature detected by the temperature sensor 11. In this case, since the fan 10 rotates integrally with the rotor 3, controlling the rotation speed of the rotor 3 is equivalent to controlling the rotation speed of the fan 10, and changes the amount of air circulating within the housing 2.

[0015] The control device 12 is a computer that constitutes an inverter for driving the generator J, and in addition to controlling the rotation speed of the rotor 3 described above, it also has the function of controlling the opening adjustment device 13 based on the power generation amount of a high-voltage battery 14 that stores the electricity generated by the generator J.

[0016] Specifically, the control device 12 controls the opening adjustment device 13 to increase the opening amount of the air inlet 7 when the amount of power generated by the high-voltage battery 14 becomes equal to or greater than an increasing threshold, and to decrease the opening amount of the air inlet 7 when the amount of power generated becomes equal to or less than a decreasing threshold.

[0017] The control device 12 has a function of controlling the rotation speed of the rotor 3 (fan 10) to a first rotation speed a or higher, which is higher than the normal speed, when the temperature detected by the temperature sensor 11 exceeds a first threshold value A, which is higher than the normal speed, while the vehicle is running. Note that normal operation refers to a state in which the engine is operated at an efficient rotation speed in order to charge the high-voltage battery 14, and includes normal control.

[0018] In addition, the control device 12 has a function of controlling the rotation speed of the rotor 3 (fan 10) to equal to or higher than a second rotation speed b which is less than the first rotation speed a when the detected temperature of the temperature sensor 11 exceeds a second threshold value B which is smaller than the first threshold value A while the vehicle is stopped.

[0019] Furthermore, the control device 12 has a function of stopping the rotation of the rotor 3 when the temperature detected by the temperature sensor 11 becomes equal to or lower than a third threshold value D, which is lower than normal.

[0020] Furthermore, the control device 12 has a plurality of operation modes that can be arbitrarily selected, and has a function of rotating the rotor 3 when a high load operation mode (Sports Mode) is selected from among the operation modes and the temperature detected by the temperature sensor 11 exceeds a fourth threshold C that is lower than the second threshold B. The magnitude relationship between these thresholds A to D is A>B>C>D.

[0021] Next, the control process of the generator J by the control device 12 will be described with reference to the flow chart shown in Fig. 2. In Fig. 2, operating state 1 is a state in which the vehicle is running and the temperature detected by the temperature sensor 11 is high. Operating state 2 is a state in which the vehicle is stopped and the detected temperature is high. Operating state 3 is a state in which the control returns to normal. Operating state 4 is a state in which a high load operating mode (Sports Mode) is selected.

[0022] The first threshold A can be set based on the upper limit temperature of the coil, and the first rotation speed a is a value higher than normal. The second threshold B is a value higher than normal temperature and lower than the first threshold A, and the second rotation speed b is a value higher than normal temperature and lower than the first rotation speed a. The third threshold D is a sufficiently low value that is permissible. The fourth threshold C is a value smaller than the second threshold B and larger than the third threshold D when the high load operation mode (Sports Mode) is selected.

[0023] When the control device 12 starts the control, it determines in step S1 whether the vehicle is running or not, and if it is running (Y), it proceeds to step S2 to determine whether the detected temperature Tc has exceeded a first threshold value A that is higher than normal. If it is determined in step S2 that the detected temperature Tc has exceeded the first threshold value A (Y), it controls the rotation speed of the rotor 3 (fan 10) to equal to or higher than a first rotation speed a that is higher than normal as the operating state 1, and then ends the control.

[0024] Next, if the control device 12 determines in step S1 that the vehicle is not running (N), the process proceeds to step S4 to determine whether or not the detected temperature Tc has exceeded a second threshold value B that is smaller than the first threshold value A. If the control device 12 determines in step S4 that the detected temperature Tc has exceeded the second threshold value B (Y), the control device 12 sets the vehicle in operating state 2 in step S5, controls the rotation speed of the rotor 3 (fan 10) to equal to or higher than a second rotation speed b that is lower than the first rotation speed a, and then ends the control.

[0025] Furthermore, if the control device 12 determines in step S4 that the detected temperature Tc does not exceed the second threshold value B (N), the process proceeds to step S6, where it determines whether the detected temperature Tc exceeds a third threshold value D that is lower than normal. If the control device 12 determines in step S6 that the detected temperature Tc exceeds the third threshold value D (Y), the control device 12 returns to normal control as the operating state 3 in step S7, and then ends the control. If the control device 12 determines in step S6 that the detected temperature Tc does not exceed the third threshold value D (N), the process proceeds to step S8, where the generator J is stopped, and then ends the control.

[0026] Next, if the control device 12 determines in step S2 that the detected temperature Tc does not exceed the first threshold A (N), the control device 12 proceeds to step S9 to determine whether or not the high-load operation mode (Sports Mode) has been selected. If the control device 12 determines in step S9 that the high-load operation mode has been selected (Y), the control device 12 determines in step S10 whether or not the detected temperature Tc has exceeded a fourth threshold C that is smaller than the second threshold B.

[0027] If it is determined in step S10 that the detected temperature Tc has exceeded the fourth threshold C (Y), then in step S11 the operation state is changed to 4, and the control is then terminated. If it is determined in step S10 that the detected temperature Tc has not exceeded the fourth threshold C (N), then in step S12 the operation state is changed to 3, and control is returned to normal control, and the control is then terminated.

[0028] Furthermore, if it is determined in step S9 that the high load driving mode (Sports Mode) has not been selected (N), control is performed in step S13 to return to normal control after driving state 3, and then the control is terminated.

[0029] The generator J described above has a liquid-cooled stator 4 and an air-cooled rotor 3. By varying the rotation speed of the air-cooling fan 10 according to the temperature state, the rotor 3 can be cooled efficiently and the rotor 3 can be prevented from becoming too hot.

[0030] In addition, in an electric vehicle, only the generator J becomes hot when the vehicle is continuously climbing a slope, the charging rate is low, and auxiliary equipment such as the air conditioner consumes a lot of power. In such a situation, the vehicle is in high load operation, so the driver is unlikely to feel uncomfortable even if the generator speed (engine speed ≒ engine sound) increases, and it is possible to eliminate a situation in which the driver feels that the power performance is insufficient.

[0031] However, in electric vehicles, the coil ends and magnets cannot be directly cooled by liquid cooling, and the path of the cooling liquid is continuously connected to multiple devices such as the generator and the inverter, so it is inefficient to change the liquid flow rate only for the convenience of the generator.

[0032] In contrast, the above-mentioned generator J has an air-cooled rotor 3 and a liquid-cooled stator 4 by a housing 2 having a water jacket 1, so there is no need to change the load of the existing water pump and it is efficient as a battery load.

[0033] Furthermore, in the above-mentioned generator J, when the detected temperature Tc of the temperature sensor 11 exceeds a first threshold value A that is higher than normal while the vehicle is running, the control device 12 controls the rotation speed of the rotor 3 (fan 10) to be equal to or higher than a first rotation speed a that is higher than normal. Therefore, when the temperature becomes high, the rotation speed is increased to increase the amount of air circulating within the housing 2, thereby dissipating heat from the stator 4 and the rotor 3.

[0034] Furthermore, when the vehicle is stopped and the charge level of the high-voltage battery 14 is low, the generator J generates electricity from the engine. In this case, the high-voltage battery 14 is only charged, so the amount of electricity generated is less than when the vehicle is traveling (only when the battery capacity is small, such as a few kWh). Therefore, when the temperature of the coil end portion exceeds a second threshold B that is smaller than the first threshold A, the control device 12 of the drive inverter increases the rotation speed of the rotor 3 compared to that during normal operation, to a second rotation speed b or higher that is less than the first rotation speed a. As a result, the generator J can be cooled according to the situation by the fan 10 that rotates together with the rotor 3, making it an efficient battery load.

[0035] Furthermore, the generator J described above can prevent unnecessary operation by setting the allowable temperature obtained in advance through experiments as a third threshold value D, and stopping the rotation speed of the rotor 3 (fan 10) (step S8 in the figure) when the detected temperature Tc is equal to or lower than the third threshold value D (step S6 in Figure 2).

[0036] Furthermore, when the high-load operation mode (Sports Mode) is selected, the generator J is assumed to be under high load. Therefore, when the temperature Tc detected by the temperature sensor 11 exceeds a fourth threshold C that is smaller than the second threshold B, the rotation speed of the rotor 3 and the fan 10 is controlled to a third rotation speed c or higher that is less than the first rotation speed a, and the control is then terminated. However, the third rotation speed c>the second rotation speed b. The generator J can cool the coil ends and the inside of the rotor core 3B in advance, suppressing excessive heat generation. When the high-voltage battery 14 is fully charged, the generator is operated in a motoring mode (a mode in which the generator is driven by an unburned engine as a load).

[0037] Furthermore, in the generator J described above, if the high-voltage battery 14 is close to being fully charged and the rotation speed of the rotor 3 is increased to increase the amount of power generation, the high-voltage battery 14 will become overcharged and will no longer be able to be charged.

[0038] Therefore, in the above generator J, when the charge level of the high-voltage battery 14 reaches or exceeds an experimentally determined threshold level on the increasing side, the rotation speed of the rotor 3 is not increased, and the opening adjustment device 13 increases the opening level of the air inlet 7, thereby increasing the amount of air circulating within the housing 2 for cooling. This allows the generator J to prevent the high-voltage battery 14 from being overcharged.

[0039] The specific configuration of the generator J according to the present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the gist of the present invention. [Explanation of symbols]

[0040] J Generator 1 Water Jacket 2. Housing 3 Rotor 4 Stator 5. First Air Chamber 6 Second Air Chamber 7 Air inlet 8 Air outlet 9 Internal Air Channel 10 Fan 11 Temperature Sensor 12 Control device 13 Opening amount adjustment device 14 High Voltage Battery

Claims

1. A generator mounted on a vehicle and having both liquid-cooling and air-cooling functions, A rotor on the central side and a stator disposed on the outer periphery side of the rotor are accommodated in a housing having a water jacket, the housing includes a first air chamber formed on one side in the axial direction of the stator, a second air chamber formed on the other side in the axial direction of the stator, an air inlet communicating with the first air chamber from the outside, and an air outlet communicating with the second air chamber from the outside, the rotor includes an internal air passage that connects the first air chamber and the second air chamber, and a fan that is disposed on at least one side of the first air chamber side and the second air chamber side and forms an air flow from the air inlet through the internal air passage to an air outlet, A generator comprising: a temperature sensor for detecting a temperature of at least the first air chamber in the housing; and a control device for controlling a rotation speed of the rotor based on the temperature detected by the temperature sensor.

2. 2. The generator according to claim 1, wherein the control device has a function of controlling the rotation speed of the rotor to equal to or higher than a first rotation speed a, which is higher than normal, when the temperature detected by the temperature sensor exceeds a first threshold A, which is higher than normal, while the vehicle is traveling.

3. 3. The generator according to claim 2, wherein the control device has a function of controlling the rotation speed of the rotor to equal to or greater than a second rotation speed b which is less than the first rotation speed a when the detected temperature of the temperature sensor exceeds a second threshold value B which is smaller than the first threshold value A while the vehicle is stopped.

4. 2. The generator according to claim 1, wherein the control device has a function of stopping the rotation of the rotor when the temperature detected by the temperature sensor becomes equal to or lower than a third threshold D that is lower than normal.

5. 4. The generator according to claim 3, wherein the control device has a plurality of operation modes that can be arbitrarily selected, and has a function of rotating the rotor when a high-load operation mode is selected from the operation modes and the detected temperature of the temperature sensor exceeds a fourth threshold C that is lower than the second threshold B.

6. The housing includes an opening amount adjustment device that changes the opening amount of the air inlet, The generator according to claim 1, characterized in that the control device has a function of controlling the opening adjustment device so as to increase the opening amount of the air inlet when the amount of power generated by a high-voltage battery that stores electricity generated by the generator becomes equal to or greater than an increasing threshold, and to decrease the opening amount of the air inlet when the amount of power generated becomes equal to or less than a decreasing threshold.

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