Automotive drive systems

Abstract

In a drive system for hybrid vehicles, the objective is to ensure acceleration performance at low speeds, achieve miniaturization, enable continuously variable transmission with minimal shift shock, and improve fuel efficiency. [Solution] The system consists of an engine 1, an input shaft 10 and an output shaft 12, a first MG 30 and a second MG 32, a planetary gear 20 consisting of three rotating members: a sun gear 22, a ring gear 24, and a carrier 28, a first transmission mechanism 3 for obtaining high and low gear ratios, and a second transmission mechanism 4 having at least one gear ratio. The input shaft 10 is connected to or can be connected to the carrier 28, the output shaft 12 is connected to the ring gear 24 and can be connected to the second MG 32, the first MG 30 is connected to the sun gear 22, the first transmission mechanism 3 is located between the output shaft 12 and the second MG 32, and the second transmission mechanism 4 can connect the input shaft 10 and the output shaft 12.

Description

Technical Field

[0001] The present invention relates to a drive device for an automobile, and more particularly to a drive device for a so-called hybrid automobile equipped with an engine and a motor generator (hereinafter referred to as "MG") as power sources.

Background Art

[0002] Conventionally, as a drive device for this type of automobile, there is a planetary gear (power split planetary gear) having three rotating elements of a sun gear, a ring gear, and a carrier for splitting an input torque, an input shaft connected to the carrier among them, a first MG connected to the sun gear, an output shaft connected to the ring gear, and a second MG connectable to this output shaft. An electrical continuously variable transmission (hereinafter referred to as "CVT") is configured using the planetary gear and the two MGs, and a transmission is provided between the output shaft and the second MG so that the second MG drives the output shaft to decelerate at low speed to obtain a large output torque. An example of such a configuration is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional drive device for an automobile, the transmission provided between the output shaft and the second MG includes at least two friction elements (B1, B2 in FIG. 7), and the transmission is achieved by switching the engagement of these friction elements, so that a large output torque can be obtained at low speed, making it possible to use a second MG with a small capacity.

[0005] However, a hydraulic pump is essential to obtain the hydraulic pressure needed to engage the friction elements of the transmission, and there are challenges such as significant power transmission losses and low power transmission efficiency due to drag friction occurring when the friction elements are not engaged.

[0006] The problems we are trying to solve are that the low power transmission efficiency is disadvantageous in terms of fuel economy, and the shifting shock in the transmission is not negligible. The objective of this invention is to improve fuel efficiency and enable continuously variable transmission that minimizes shifting shocks. [Means for solving the problem]

[0007] The automotive drive system of the present invention comprises an input shaft capable of receiving power from an engine, an output shaft, a first motor-generator, a second motor-generator, a planetary gear consisting of three rotating elements: a sun gear, a ring gear, and a carrier, a first gear shift mechanism for obtaining high and low gear ratios, and a second gear shift mechanism having at least one gear ratio, wherein the input shaft is connected to or can be connected to the carrier, the output shaft is connected to the ring gear and can be connected to the second motor-generator, the first motor-generator is connected to the sun gear, the first gear shift mechanism is provided between the output shaft and the second motor-generator, and the second gear shift mechanism is capable of connecting the input shaft and the output shaft. [Effects of the Invention]

[0008] As configured as described above, the automotive drive system of the present invention improves fuel efficiency and allows driving in drive modes including continuously variable transmission, which reduces shifting shock. [Brief explanation of the drawing]

[0009] [Figure 1] This is a skeleton diagram showing the main parts of an automobile drive system according to Embodiment 1 of the present invention. [Figure 2] This is a diagram showing the operation table for Example 1. [Figure 3]This is a skeleton diagram showing the main parts of an automobile drive system according to Embodiment 2 of the present invention. [Figure 4] This is a diagram showing the operation table for Example 2. [Figure 5] This is a skeleton diagram showing the main parts of an automobile drive system according to Embodiment 3 of the present invention. [Figure 6] This is a diagram showing the operation table for Example 3. [Modes for carrying out the invention]

[0010] Hereinafter, an automobile drive system according to an embodiment of the present invention will be described with reference to the figures based on an example. [Examples]

[0011] Figure 1 is a skeleton diagram of the main components of an automobile drive system according to Embodiment 1 of the present invention. The automobile drive system of Embodiment 1 consists of four parallel shafts, which, from bottom to top in Figure 1, are the first shaft on which the output shaft 12 is located, the second shaft on which the input shaft 10, planetary gear 20, and first MG 30 are located, the third shaft on which the counter shaft 14 is located, and the fourth shaft on which the MG shaft 32a connected to the second MG 32 is located. Although Figure 1 shows these four shafts arranged on a plane, they do not necessarily have to be on a plane in reality. Also, the circles in the figure illustrate the arrangement of bearings, although their explanation is omitted.

[0012] The input shaft 10 is connected to the crankshaft 1a of the power source engine 1 via a damper 1b. The planetary gear 20 is generally called a single-pinion type and has three rotating elements: a sun gear 22, a ring gear 24, and a carrier 28. The sun gear 22 is connected to the first MG 30, the carrier 28 is connected to the input shaft 10, and the ring gear 24 is integrated with the first gear 24a.

[0013] The first gear 24a is connected to the output shaft 12 and the counter shaft 14 via the second gear 12a and the third gear 14a, which mesh with it. In other words, the output shaft 12 is connected to the ring gear 24 and the counter shaft 14 via these gears. The output shaft 12 outputs power from an integrated output gear 12b to drive the wheels of the automobile via a differential gear (not shown). A parking gear 12d is also provided integrally with the output shaft 12, but this is well known and will not be explained.

[0014] The MG shaft 32a connected to the second MG 32 and the counter shaft 14 enable two-stage speed control, high and low, as described later. Specifically, the fourth gear 32b and fifth gear 32c, which are integrated with the MG shaft 32a, mesh with the sixth gear 14b and seventh gear 14c, which are rotatably mounted on the counter shaft 14. The counter shaft 14 and the sixth gear 14b and seventh gear 14c can be selectively connected by shifting the first sleeve 14d, which is mounted on the counter shaft 14, in the axial direction.

[0015] Here, the configuration and operation common to other sleeves described later will be explained using the first sleeve 14d as an example. Specifically, the first sleeve 14d is positioned radially outward of the first hub 14e, which is integrated with the counter shaft 14, and its rotational direction is integrated with the first hub 14e, while its axial direction is shiftable. The dog teeth 14f and 14g formed on the surfaces of the sixth gear 14b and the seventh gear 14c facing the first sleeve 14d, respectively, selectively engage with one of them when the first sleeve 14d shifts. Figure 1 shows the neutral position, where neither the dog teeth 14f nor the dog teeth 14g are engaged. The engagement between the first sleeve 14d and the dog teeth 14f and 14g is achieved by controlling the rotational speed difference between them to be close to zero, and conversely, the disengagement is achieved by controlling the torque transmission between them to be close to zero.

[0016] Thus, when the first sleeve 14d is shifted to the right in FIG. 1, a low (Lm) gear ratio is obtained, and when it is shifted to the left, a high (Hm) gear ratio is obtained. Since the countershaft 14 and the output shaft 12 are connected via the first gear 24a, they constitute the first transmission mechanism 3 of the present invention between the second MG 32 and the output shaft 12. The shift of the first sleeve 14d is performed by a shift fork and an actuator not shown, but since these configurations are well-known, the drawings and their descriptions are omitted.

[0017] An eighth gear 10a is rotatably provided on the input shaft 10, and the eighth gear 10a meshes with a ninth gear 12c integral with the output shaft 12. A second sleeve 10d provided on the input shaft 10 is disposed radially outside a second hub 10e integral with the input shaft 10, and by shifting axially, it engages with a dog tooth 10f and a dog tooth 10g formed on the first gear 24a, and can be selectively connected to the first gear 24a and the eighth gear 10b. By shifting the second sleeve 10d axially, a two-stage gear ratio can be obtained between the input shaft 10 and the output shaft 12. That is, when the second sleeve 10d is shifted to the right in FIG. 1, it has a low (Le) gear ratio, and when shifted to the left, it has a high (He) gear ratio, and constitutes the second transmission mechanism of the present invention between the input shaft 10 and the output shaft 12.

[0018] The above is the configuration of this embodiment. Here, for the following description, taking the above gear ratios as examples, they are as follows. Lm (rotation speed of the second MG 32 / rotation speed of the output shaft 12): 1.8 Hm (same as above): 0.6 Le (rotation speed of the input shaft 10 / rotation speed of the output shaft 12): 1.60 He (same as above): 1. C Also, taking the ratio of the number of teeth of the sun gear 22 to the number of teeth of the ring gear 24 of the planetary gear 20 as ρ, ρ is set to 0.40. In the following description, the rotation direction of the engine 1 is defined as "forward rotation", and the rotation opposite to it is defined as "reverse rotation".

[0019] Next, the operation and function of the automotive drive system shown in Figure 1 will be explained in accordance with the operation table shown in Figure 2. In the operation table in Figure 2, each drive mode described below is assigned to the vertical direction, and the operating status and gear ratio of the two sleeves and two MGs are assigned to the horizontal direction. Specifically, the first sleeve 14d is designated as S1, the second sleeve 10d as S2, the first MG30 as MG1, and the second MG32 as MG2. The arrows in the table for each sleeve indicate the shift direction of each sleeve and engage with the dog teeth opposite the shift direction. In the case of the MGs, power generation is represented as G and drive as D. The gear ratio value is the rotational speed of the second MG32 / the rotational speed of the output shaft 12 in EV mode, and the high-efficiency drive in HV mode is the rotational speed of the input shaft 10 / the rotational speed of the output shaft 12. Furthermore, the # shown in the table for the first sleeve 14d indicates that the first sleeve 14d may shift in that drive mode.

[0020] Although not shown in the diagram, the automotive drive system shown in Figure 1 is equipped with a battery, various sensors, a controller, an inverter, a shift lever, etc., as needed, in addition to the aforementioned shift fork and actuator, in order to operate it, and the following operations are basically performed based on the instructions of the controller.

[0021] The drive modes of the drive system shown in Figure 1 include "EV mode" when engine 1 is stopped and "HV mode" when engine 1 is running. In EV mode, the vehicle is driven as an EV (electric vehicle) by the second MG32, while in HV mode, except for ML and MH described later, the vehicle is driven as an electromechanical CVT.

[0022] First, let's explain the EV mode, which uses electricity stored in the battery as the power source. In EV mode, power is supplied from the battery to the second MG32 for driving, or during braking called regenerative braking, the second MG32 generates electricity to charge the battery. As described above, the first transmission mechanism 3 selects two gear ratios between the second MG32 and the output shaft 12, selecting EL with a gear ratio of Lm for starting and low-speed driving, and EH with a gear ratio of Hm for high-speed driving.

[0023] Switching between EL and EH is done by setting the torque of the second MG32 to 0. However, to avoid the drive torque or braking torque temporarily becoming 0, it is also possible to switch to the HV mode described later and switch between the gear ratios Lm and Hm while driving in HV mode. Therefore, it is important to shift the first sleeve 14d in the appropriate direction in preparation for switching to HV mode next. Note that in EV mode, reverse is the same EL in the operation table, and the rotation direction of the second MG32 is the opposite of that in forward.

[0024] Next, the HV mode driven by engine 1 will be described. The HV mode primarily operates as an electromechanical CVT (continuously variable transmission) using planetary gears 20, the first MG 30, and the second MG 32. A first transmission mechanism 3 is interposed between the second MG 32 and the output shaft 12, resulting in two drive stages, HL and HH. The HV mode also has ML and MH, which are driven from the input shaft 10 with a fixed gear ratio by the second transmission mechanism 4, although these are not electromechanical CVTs.

[0025] First, although it is well known, when the vehicle is stopped, the first MG30 is rotated in reverse in the HL state shown in Figure 2, and when the vehicle is in motion, the first MG30 is used to generate electricity regardless of the drive mode.

[0026] Next, although electromechanical CVTs are well known, their overview will be explained. The carrier 28, driven from the input shaft 10 by the power of the engine 1, transmits its torque to the sun gear 22 and the ring gear 24. The torque acting on the ring gear 24 mechanically drives the output shaft 12. Meanwhile, the torque acting on the sun gear 22 generates electricity in the first MG 30, which supplies the resulting power to the second MG 32, which drives the output shaft 12 via the first transmission mechanism 3. In other words, the torque of the sun gear 22 is electrically transmitted to the output shaft 12. The rotational speed ratio between the input shaft 10 and the output shaft 12 changes steplessly according to the vehicle-side drive load acting on the output shaft 12 and the engine power. Note that in HV mode, reverse is the same HL in the operation table, and the rotation direction of the second MG 32 is the opposite of that in forward mode.

[0027] In actual driving, the vehicle is often in EV mode when starting. In that case, it starts in EL mode, and when the driving load increases or the battery charge decreases, it switches to HV mode by starting engine 1 as described above.

[0028] When the vehicle speed increases while driving in HL mode, and the gear ratio (rotational speed of input shaft 10 / rotational speed of output shaft 12) reaches Le, the speed difference between the second sleeve 10d and the eighth gear 10a becomes zero. At this point, the second sleeve 10d is shifted to the right and engages with the dog teeth 10f, stopping the generation and driving of the first MG30 and second MG32. This switches to mechanical drive with gear ratio Le, driven by the eighth gear 10a and the ninth gear 12c. This is ML mode. ML mode is mechanical drive and has no losses associated with electrical drive.

[0029] Furthermore, while running in ML mode, the rotational speeds of the first MG30 and the second MG32 can be freely changed, allowing the first transmission mechanism 3 to be switched between low (Lm) and high (Lh). Then, with the first transmission mechanism 3 switched to high, the power generation and drive of the first MG30 and the second MG32 are restored using the reverse procedure described above, and when the transmission torque of the second sleeve 10d becomes 0, the second sleeve 10d is returned to neutral, switching to HH mode.

[0030] Similarly, when the gear ratio reaches Hm while driving, the second sleeve 10d can be shifted to the left to switch to MH, and the first gear mechanism 3 can be switched while driving in MH.

[0031] Thus, ML and MH are drive positions that allow switching of the first transmission mechanism 3 while driving. Whether to switch between HL and HH in ML or MH should be determined by the vehicle's speed and the state of the drive load. Also, the gear ratio basically does not change when switching from HV mode to ML and HH, or when switching back to HV mode.

[0032] After switching to HH, the rotational speed of the first MG30 decreases along with the gear ratio and eventually stops. This state is called H-Hs, and the gear ratio is He / (1+ρ), which corresponds to 0.73 in the gear ratio-tooth ratio described above. When the first MG30 stops, it does not generate electricity and the electrical drive becomes 0, so it is considered a mechanical drive, and this gear ratio is called the mechanical point and is considered a high-efficiency drive. In this case, if the gear ratio is around this value, the electrical drive is close to 0, so a gear ratio of around 0.73 can be considered a high-efficiency drive, and there is no need to switch the sleeve in H-Hs. The above three high-efficiency drives are suitable for use in cruising, and in order to improve fuel efficiency during cruising, the first sleeve 14d can be set to neutral and the second MG32 can be stopped.

[0033] The above explains the switching process during acceleration from a standstill to high speed. Conversely, switching during deceleration is basically the same as switching during acceleration, but in the reverse order.

[0034] The above describes the operation of Example 1, and the following effects can be obtained in Example 1. As described above, since the first transmission mechanism 3 is provided, the capacity of the second MG required to obtain the required output torque can be reduced, as in the conventional example, and since the gear ratio is determined by the first transmission mechanism 3, which consists of two pairs of gears, there is a high degree of freedom in setting the gear ratio. For example, it is easy to increase the driving force in the low-speed range and when reversing by increasing Lm, and to reduce the rotational loss of the MG2 during high-speed driving by decreasing Hm. Furthermore, since the gear ratio switching of the first transmission mechanism 3 is performed while driving ML or MH, the gear ratio does not change during switching, and therefore shift shock is less likely to occur, resulting in a smooth switch. In addition, since a friction clutch and hydraulic pump are not required for switching, the power transmission efficiency is high and fuel efficiency can be improved. Furthermore, fuel efficiency can be further improved by using ML and MH during cruising. In that case, by putting the first sleeve 14d in neutral and stopping the second MG32, the rotational loss of the second MG32 can be avoided and fuel efficiency can be further improved.

[0035] Furthermore, as can be seen in Figure 1, the first transmission mechanism 3, the second transmission mechanism 4, and the output gear 12b can be easily arranged to overlap in the axial direction. This reduces the overall axial length of the device, which is an advantage as it makes it easier to mount in front-wheel-drive (FF) vehicles with the engine 1 mounted transversely. [Examples]

[0036] Next, an automobile drive system according to Embodiment 2 of the present invention will be described. Figure 3 is a skeleton diagram of the main parts of the automobile drive system according to Embodiment 2 of the present invention. Here, the parts that differ from Embodiment 1 will be described in detail, and parts that are substantially the same as those in Embodiment 1 will be given basically the same names and reference numerals and their descriptions will be omitted.

[0037] The difference between Embodiment 2 and Embodiment 1 lies in the configuration of the second gear shifting mechanism 4. Specifically, a newly installed connecting gear 10b, which is rotatably mounted on the input shaft 10, meshes with the seventh gear 14c on the counter shaft 14. When the second sleeve 10d is shifted to the left, it engages with the dog teeth 10g of the connecting gear 10b. As a result, when the second sleeve 10d is shifted to the left, the input shaft 10 is connected to the MG shaft 32a via the connecting gear 10b and the seventh gear 14c. Although the axial positions of the eighth gear 10a and the ninth gear 12c are slightly different from those in Embodiment 1, the fact that the gear that connects when the second sleeve 10d is shifted to the right is the eighth gear 10a remains the same as in Embodiment 1.

[0038] The above describes the configuration of this embodiment. Here, the gear ratios described in Embodiment 1 are used as an example as follows. Lm:2.2 Hm:0.8 Note that the "number of teeth of connecting gear 10b / number of teeth of the 7th gear 14c" is the same as that of Hm. Furthermore, Le, He, and ρ are the same as in Example 1.

[0039] Next, the operation and function of Example 2 will be explained along with the operation table shown in Figure 4. As described above, only the operation when the second sleeve 10d is shifted to the left differs from Example 1, but as can be seen in Figure 4, in the high-efficiency drive of HV mode, the two drives, M-LL and MH, differ from those of Example 1. That is, the new M-LL obtains the same gear ratio: 2.2 as Lm by being driven via the MG shaft 32a. In this case, when the gear ratio becomes 2.2 in HL of HV mode, the second sleeve 10d is shifted to switch to M-LL.

[0040] Furthermore, in MH mode, the seventh gear 14c is connected to the counter shaft 14 via the first sleeve 14d, thus obtaining the same gear ratio of 0.8 as Hm mode. In this case, when the gear ratio becomes 0.8 in HH mode in HV mode, the second sleeve 10d is shifted to switch to MH mode. Note that the operation is the same as in Embodiment 1, including the fact that ML is suitable for shifting the first sleeve 14d.

[0041] The above describes the operation of Example 2. In addition to the effects described in Example 1, this example has the following advantages. Specifically, in M-LL mode, the mechanical drive has a gear ratio of 2.2, allowing for full power drive of engine 1, improving performance in acceleration and uphill driving. Similarly, in MH mode, a gear ratio suitable for high-speed cruising enables highly efficient drive, improving fuel efficiency, especially on highways.

[0042] Next, an automobile drive system according to Embodiment 3 of the present invention will be described. Figure 5 is a skeleton diagram of the main parts of the automobile drive system according to Embodiment 3 of the present invention. Here, the parts that differ from Embodiment 1 will be described in detail, and parts that are substantially the same as those in Embodiment 1 will be given basically the same names and reference numerals and their descriptions will be omitted.

[0043] The first difference between Embodiment 1 and Embodiment 3 is that Embodiment 3 is suitable for a rear-wheel-drive vehicle, where the engine 1 is positioned longitudinally at the front of the vehicle, whereas Embodiment 1 is a configuration suitable for a so-called front-wheel-drive vehicle with the engine 1 positioned transversely. Furthermore, the input shaft 10 and the output shaft 12 share the same axis, and the planetary gear 20, the first MG 30, and the second MG 32 are also positioned on the same axis. In addition, if the entire set of transmission mechanisms described below is referred to as the transmission mechanism group 5, the transmission mechanism group 5, the second MG 32, the planetary gear 20, and the first MG 30 are arranged in the axial direction from the engine 1 side.

[0044] A first counter shaft 14 and a second counter shaft 16 are arranged parallel to and adjacent to the input shaft 10 and output shaft 12. The first counter shaft 14 is connected to the output shaft 12 via a first connecting gear pair 14g, and the second counter shaft 16 is connected to the carrier shaft 28a, which is integrated with the carrier 28, via a second connecting gear pair 16a. A parking gear 12d is also provided integrally with the first counter shaft 14, which is connected to the output shaft 12. Note that in Figure 5, these shafts are drawn side by side on a plane, as in the case of Embodiment 1, but in reality, they do not have to be on a plane.

[0045] The fourth gear 32b and fifth gear 32c, which are integrated with the MG shaft 32a connected to the second MG 32, mesh with the sixth gear 14b and seventh gear 14c, respectively, which are rotatably mounted on the first counter shaft 14. Similar to the first embodiment, the first counter shaft 14 and the sixth gear 14b and seventh gear 14c can be selectively connected by shifting the first sleeve 14c in the axial direction. That is, shifting the first sleeve 14c to the right in Figure 5 yields a low gear ratio, and shifting it to the left yields a high gear ratio. As described above, the first counter shaft 14 is connected to the output shaft 12, and these constitute the first gear shift mechanism 3 of the present invention.

[0046] The input shaft 10 has a first input gear 10h and a second input gear 10k integrated into it, which mesh with the tenth gear 14h and the eleventh gear 14k, respectively, which are rotatably mounted on the first counter shaft 14. The first counter shaft 14 and the tenth gear 14h and the eleventh gear 14k can be selectively connected by shifting the second sleeve 10c in the axial direction. In other words, as in the first embodiment, shifting the second sleeve 10c to the left engages with the dog teeth 10f to obtain a low gear ratio, and shifting it to the right engages with the dog teeth 10g to obtain a high gear ratio. As described above, the first counter shaft 14 is connected to the output shaft 12, so these constitute the second gear shifting mechanism 4 of the present invention.

[0047] The first input gear 10g and the second input gear 10h mesh with the 12th gear 16b and the 13th gear 16c, respectively, which are rotatably mounted on the second counter shaft 16. The second counter shaft 16 and the 12th gear 16b and the 13th gear 16c can be selectively connected by shifting the third sleeve 16d in the axial direction. That is, the third sleeve 16d is located on the outside of the third hub 16e, which is integrated with the second counter shaft 16, and the 12th gear 16b and the 13th gear 16c have dog teeth 16f and 16g, respectively, on the faces facing the third sleeve 16d. In other words, shifting the third sleeve 16d to the left yields a low (Lc) gear ratio, and shifting it to the right yields a high (Hc) gear ratio. As described above, the second counter shaft 16 is connected to the carrier shaft 28a, and these constitute the third gear shifting mechanism 6 of the present invention between the input shaft 10 and the carrier 28.

[0048] A 14th gear 16h is rotatably mounted on the second counter shaft 16, and the 14th gear 16h meshes with a 15th gear 32d which is integrated with the second MG shaft 32a. The second counter shaft 16 and the 14th gear 16h can be connected by shifting the fourth sleeve 16k. That is, the fourth sleeve 16k rotates in the same direction as the fourth hub 16m which is integrated with the second counter shaft 16, but is shiftable in the axial direction, and can engage with the dog teeth 16n formed on the 14th gear 16h by shifting the fourth sleeve 16k. In other words, the second counter shaft 16 and the second MG shaft 32a can be connected via the 14th gear 16h and the 15th gear 32d by shifting the fourth sleeve 16k.

[0049] The connection relationships of each rotating member of the planetary gear 20 are basically the same as in Embodiment 1. That is, the input shaft 10 and the carrier 28 can be connected via the third speed change mechanism 6 described above, the sun gear 22 is connected to the first MG 30, and the ring gear 24 is connected to the output shaft 12.

[0050] Next, we will describe a unit that is retrofitted along the second countershaft 16, commonly referred to as a power take-off (PTO). The 14th gear 16h can be meshed with the driven gear 16o, shown by the dashed line. The driven gear 16o is a component of the PTO and can take power externally.

[0051] Next, the actuator will be described. As mentioned above, this embodiment has four sleeves, but for example, the first sleeve 14d and the fourth sleeve 16k are linked to move in conjunction for the operation described later. That is, the third sleeve 16d is shifted to one side and then the fourth sleeve 16k is shifted, so it is easy to operate both sleeves with a single actuator. These are well known, so the illustrations and explanations will be omitted.

[0052] The above describes the configuration of this embodiment. For the purpose of the explanation described later, the gear ratios mentioned above will be used as an example as follows. Lm:2.22 Hm:0.70 Le:2.45 He: 1.22 Lc (rotational speed of input shaft 10 / rotational speed of carrier 28): 1.80 Hc (same as above): 0.9 ρ:0.45

[0053] Next, the operation and function of Example 3 will be explained. Here again, explanations will be omitted for parts that are basically the same as in Example 1. Figure 6 shows the operation table corresponding to Figure 2 of Example 1. The difference from Example 1 is that two sleeves have been added in the lateral direction. That is, the third sleeve 14n is designated as S3 and the fourth sleeve 16k is designated as S4. The drive modes assigned in the vertical direction will be explained in the following operation description, focusing on the parts that differ from Example 1. Note that arrows enclosed in parentheses indicate that the sleeve is engaged but does not participate in power transmission.

[0054] Firstly, regarding the EV mode, in addition to EL and EH in Example 1, E-LL and E-HH have been added. In both of these added modes, the fourth sleeve 16k engages with the dog teeth 16n, connecting the carrier shaft 28a and the second counter shaft 16 to the MG shaft 32a. Therefore, the first MG 30 can also participate in the drive.

[0055] In other words, in the E-LL, when the first MG30 generates torque in the forward rotation direction, it drives the output shaft 12 in the forward rotation direction via the carrier shaft 28a and MG shaft 32a. On the other hand, the torque of the first MG30 acts on the ring gear 24, i.e., the output shaft 12, in the reverse rotation direction. Even after subtracting this, the torque driving the output shaft 12 in the forward rotation direction is large, and this is 6.9 times the torque of the first MG30. Therefore, the torque of the output shaft 12 in the E-LL is the sum of 2.22 times the torque of the second MG32 in the EL and 6.9 times the torque of the first MG30. Consequently, it is possible to exert a very large torque, albeit in the extremely low-speed range, and this is also true in reverse.

[0056] Furthermore, in the E-HH, 0.66 times the torque of the first MG30 acts on the output shaft 12 by the same principle as above, so this is added to the torque of the second MG32, which is 0.6 times the torque in the EH. In other words, the E-LL and E-HH are driven by two MGs, and can obtain a larger output torque than the EL and EH.

[0057] Next, the difference between the HV mode and the first embodiment is that the HV mode has a two-stage gear ratio provided by the third gear mechanism 6 between the input shaft 10 and the carrier shaft 28a. Therefore, HL uses both Lm from the first gear mechanism 3 and Le from the third gear mechanism 6, and HH similarly uses both Hm and He. Similarly, H-Lh also uses both Hm and Le. The switching between these three HV modes will be explained later in the section on high-efficiency drive, but all three HV modes are electric CVTs.

[0058] Next, regarding the high-efficiency drive, the ML and MH positions by the second transmission mechanism 4 are the same as in Embodiment 1, but the difference from Embodiment 1 is that in both positions, in addition to the first transmission mechanism 3, the newly added third transmission mechanism 6 can be switched. That is, in ML, it is desirable to shift the first sleeve 14d in preparation for switching from HL to H-Lh, and in MH, it is desirable to shift the third sleeve 16d in preparation for switching from H-Lh to HH. In other words, the switching of HV mode is mainly performed by the mechanical drive of ML and MH.

[0059] Next, M-LL and M-HH are performed by engaging the fourth sleeve 16k with the dog teeth 16n, as described in the EV mode, to connect the second counter shaft 16 and the MG shaft 32a. This transmits the torque from the input shaft 10 to the output shaft 12 via the third transmission mechanism 6 and the first transmission mechanism 3. When both the third transmission mechanism 6 and the first transmission mechanism 3 are set to low (Le, Lm), M-LL is achieved, obtaining a gear ratio equivalent to the first gear of a typical automatic transmission (AT). In HV mode, when the gear ratio becomes 5.1 in HL, the fourth sleeve 16k is shifted to switch to M-LL. M-LL is a mechanical drive and differs from HL in that it can be driven with the full power of the engine.

[0060] Next, when both the third gear mechanism 6 and the first gear mechanism 3 are set to high (He, Hm), the setting is M-HH, which allows for mechanical overdrive with a ratio of 0.81. In this case as well, when the gear ratio becomes 0.81 in HH mode, the fourth sleeve 16k is shifted to switch to M-HH.

[0061] Next, the addition of the third gear shifting mechanism 6 increases the number of mechanical points where the first MG30 stops in HL and HH to two, which is different from the case of Example 1. In other words, H-Ls and H-Hs are the two positions where high-efficiency drive is achieved. As explained in Example 1, in the four positions of ML, MH, H-Ls, and H-Hs, the first sleeve 14d can be neutralized and the second MG32 stopped during cruising.

[0062] As shown in Figure 6, the gear ratios for H-Ls and MH are similar, but they can be used interchangeably depending on the driving speed and drive load. Furthermore, it is possible to set appropriate gear ratios considering these different uses.

[0063] Next, we will explain the power take-off, commonly referred to as the PTO. A PTO gear 16o, shown by the dashed line, can be retrofitted and meshed with the 14th gear 16h, which can be driven by the 2nd M / G32. This PTO gear 16o meshes with the 14th gear 16h to extract power externally and is used for purposes other than driving the automobile. The PTO gear 16o can be driven in the following ways: Firstly, when the 1st sleeve 14d and the 4th sleeve 16k are in the neutral position, it can be driven by the 2nd M / G32 by supplying power from the battery. Secondly, when the 4th sleeve 16k is shifted, the 3rd sleeve 16d is shifted and connected to the 12th gear 16b or the 13th gear 16c, and then the engine 1 is started to generate power in the 1st M / G30 and supply power to the 2nd M / G32, allowing for long-term power extraction regardless of battery capacity. In the above cases, power can be extracted at any rotational speed while the vehicle is stationary. Furthermore, while the vehicle is in motion, the 14th gear 16h rotates in any drive mode, so power can be extracted from it.

[0064] The above describes the operation of Example 3. In addition to the effects described in Example 1, this example offers the following advantages. Specifically, by providing a third transmission mechanism 6 and enabling the connection of the second counter shaft 16 and the second MG shaft 32a, the number of drive modes increases and becomes more diverse, and a large drive torque can be generated. For example, in EV mode, the first MG 30 can participate in the drive in addition to the second MG 32. In HV mode, two gear ratios, low (Lc) and high (Hc), are added to the CVT drive, increasing the drive torque and broadening the degree of improvement in fuel efficiency. These are suitable for driving commercial vehicles or SUVs, which have a large range of fluctuations in drive load. Furthermore, this configuration is also suitable for equipping such vehicles with a PTO.

[0065] The automotive drive system of the present invention can be implemented in a manner that combines control features such as optimal setting of the gear ratio, optimization of the arrangement of shafts, gears and bearings, and a method for selecting the drive mode, based on the general knowledge of those skilled in the art. Furthermore, some or all of the parts connected by sleeves as described above can be replaced with friction clutches, and in particular, a one-way clutch can be provided between the 12th gear 16b and the second counter shaft 16 in parallel with the third sleeve 16d. [Industrial applicability]

[0066] The automotive drive system of the present invention can be applied to passenger cars and commercial vehicles that require smooth gear changes, particularly low running costs, and reduced environmental impact. However, it is not limited to these vehicles and can be applied to a variety of vehicles utilizing internal combustion engines and motor-generators. [Explanation of Symbols]

[0067] 1 Engine 3. First transmission mechanism 4. Second transmission mechanism 5. Transmission Mechanism Group 6. Third transmission mechanism 10 input axes 12 Output shafts 20 Planetary gears 30. First Motor Generator (MG) 32. Second Motor Generator (MG)

Claims

1. An input shaft capable of receiving power from the engine, Output shaft and, First motor generator, The second motor generator, A planetary gear system consisting of three rotating elements: a sun gear, a ring gear, and a carrier. A first gear shift mechanism that obtains high and low gear ratios, A second transmission mechanism having at least one gear ratio, It consists of, The input shaft is connected to or connectable to the carrier, the output shaft is connected to the ring gear and connectable to the second motor-generator, and the first motor-generator is connected to the sun gear. An automobile drive system characterized by having the first transmission mechanism between the output shaft and the second motor-generator, and having the second transmission mechanism capable of connecting the input shaft and the output shaft.

2. The automobile drive system according to claim 1, characterized in that a third transmission mechanism having at least two gear ratios is provided between the input shaft and the carrier.

3. The drive device for an automobile according to claim 1, wherein the drive device has at least four shafts, which are arranged in parallel and designated as the first shaft, second shaft, third shaft, and fourth shaft in order from one end, the output shaft is arranged on the first shaft, the input shaft, the planetary gear and the first motor-generator are arranged on the second shaft, the counter shaft connected to the ring gear is arranged on the third shaft, and the second motor-generator is arranged on the fourth shaft, the second gear shift mechanism is configured between the first shaft and the second shaft, and the first gear shift mechanism is configured between the third shaft and the fourth shaft.

4. The automobile drive system according to either claim 1 or 2, characterized in that the input shaft, the output shaft, the planetary gear, the first motor-generator, and the second motor-generator are provided on the same axis, and a first counter shaft connected to the output shaft and a second counter shaft connected to the carrier are arranged parallel to these, and the first speed change mechanism is configured between the second motor-generator and the first counter shaft, the second speed change mechanism is configured between the input shaft and the first counter shaft, and the third speed change mechanism is configured between the input shaft and the second counter shaft.

5. The automobile drive device according to any one of claims 1 to 4, characterized in that the input shaft and the second motor-generator can be connected.

6. The automotive drive system according to either 4 or 5, characterized in that a power take-off device drivable by the second motor-generator can be attached.

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