electric vehicle drive unit

Abstract

In addition to miniaturizing the case that houses the motor and power control unit, the present invention provides a drive unit for an electric vehicle that can also improve the rigidity of the case. [Solution] Motors 2 and 3, a power converter 19, and a terminal block 17 connecting the MG power line 5 and the INV power line 22 are housed in a case 13. A cover portion 15 attached to the side wall surface of the case 13 is fixed to the case 13 by a plurality of bolts 16. The terminal block 17 is provided facing the inner surface of the side wall surface of the case 13, including the portion that the outer peripheral edge of the cover portion 15 abuts against. A service hole 24 is formed in the terminal block 17 in the portion of the side wall surface of the case 13 that is outside the outer peripheral edge of the cover portion 15 and facing the terminal block 17. A flange portion 25 is formed on the outer periphery of the cover portion 15 along the outer peripheral edge of the cover portion 15, and the flange portion 25 has a base surface for indicating the model.

Description

Technical Field

[0001] This invention relates to a drive unit for an electric vehicle that houses a motor as a driving force source and a power control unit that controls the motor in one case.

Background Art

[0002] Patent Document 1 describes an in-vehicle unit in which a transaxle case housing a motor, a power control unit that drives the motor, and an electric unit housing electrical components are integrated. This in-vehicle unit is configured such that an electric unit is mounted on an electromechanical integrated unit in which the power control unit is attached to the upper surface of the transaxle case. The motor housed in this transaxle case and the inverter housed in the power control case are electrically connected via a bus bar.

Prior Art Documents

Patent Documents

[0003] <s

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the in-vehicle unit described in Patent Document 1, the motor housed in the transaxle case and the inverter housed in the power control unit case are connected via a bus bar. On the other hand, when the transaxle and electrical components including the inverter are housed in one case, one of the members of the transaxle and the inverter is connected to the bus bar and housed in the case, and then the other member is housed in the case, and thereafter, the other member and the bus bar are connected. Therefore, it is necessary to provide a working space for fixing the bus bar and one member, and there is a possibility that the case will be enlarged.

[0005] Furthermore, if service holes are formed in the case to prevent the need for such workspace, the rigidity around the service holes will decrease. As a result, vibrations generated when the motor is driven or the power control unit is operating may be transmitted to the case, potentially causing the case to vibrate or generating abnormal noises as radiated sound.

[0006] This invention was made in view of the above-mentioned technical problems, and the object of this invention is to provide a drive unit for an electric vehicle that can miniaturize the case housing the motor and the power control unit, as well as improve the rigidity of the case. [Means for solving the problem]

[0007] To achieve the above objective, this invention provides a drive unit for an electric vehicle, comprising a motor as a driving force source, a power conversion device for controlling the power supplied to the motor, and a terminal block for connecting a first power line of the motor and a second power line of the power conversion device, all housed in a case, the drive unit comprising a cover portion attached to the side wall surface of the case, the cover portion being fixed to the case by a plurality of bolts along its outer edge, the terminal block being provided on the inner surface of the side wall surface of the case, including the portion that the outer edge of the cover portion abuts against, a service hole being formed in the portion of the side wall surface of the case that is outside the outer edge of the cover portion and facing the terminal block, for inserting a tool for fixing the first power line or the second power line to the terminal block, a flange portion having a predetermined length along the outer edge of the cover portion being formed between the service hole and the outer edge of the cover portion in the case, or on the outer edge of the cover portion, and the flange portion having a base surface for indicating a predetermined model, including the model of the motor.

[0008] Furthermore, in this invention, the terminal block and the power conversion device may be arranged above the motor in the vertical direction.

[0009] Furthermore, in this invention, the terminal block and the power conversion device may be arranged side by side in the horizontal direction.

[0010] Furthermore, in this invention, the case has an opening that is closed by the cover portion, and the flange portion may be provided between the service hole and the opening. [Effects of the Invention]

[0011] According to this invention, by housing the motor and power converter in a case, the drive unit, which integrates the motor and power converter, can be miniaturized. Furthermore, by configuring the drive unit in this way, a service hole for inserting a tool to fix the first or second power line is formed in the case, and a flange portion having a predetermined length along the service hole is formed in the case or cover portion. Therefore, even when the cover portion and the case are fixed with bolts while avoiding the terminal block, the rigidity of the portion of the cover portion between the bolts can be increased. As a result, because the flange portion is located near the service hole, even if vibrations generated when the motor is driven or the power converter is operating are transmitted to the case, vibrations of the wall surface near the service hole can be suppressed, and the generation of abnormal noises such as radiated noise can be suppressed.

[0012] Furthermore, since the flange portion has a base surface for clearly indicating a predetermined model, including the motor model number, there is no need to separately provide a base for printing the model number on other parts of the case or cover. In other words, because the flange portion serves both to improve the rigidity of the cover and as a base for printing the model number, the drive unit can be made smaller. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a side view illustrating the configuration of a drive unit in an embodiment of this invention. [Figure 2]Figure 2 is a cross-sectional view along the line II-II in Figure 1. [Figure 3] Figure 3 is a magnified view showing the power converter and rear cover before they are mounted to the case, illustrating the service holes and terminal block. [Figure 4] Figure 4 is a perspective view illustrating the structure of the flange. [Modes for carrying out the invention]

[0014] This invention will be described based on the embodiments shown in the figures. The embodiments described below are merely examples of how this invention can be implemented and do not limit it.

[0015] Figure 1 schematically shows a side view illustrating an example of a drive unit for an electric vehicle in an embodiment of this invention, and Figure 2 schematically shows a cross-sectional view along the line II-II in Figure 1. The electric vehicle shown in Figures 1 and 2 is a hybrid vehicle equipped with an engine 1 and two motors 2 and 3 as driving forces. This electric vehicle is configured so that the power from these driving forces is transmitted to a pair of front wheels. That is, the rotational axes of the engine 1 and each of the motors 2 and 3 are arranged along the width direction of the vehicle. Figure 1 shows a side view seen from one side in the width direction of the vehicle. Note that the vertical direction in Figure 1 is the vertical direction, and the left side is the front side of the vehicle.

[0016] Each of the motors 2 and 3 is configured similarly to the motors used as the driving force source in conventional electric vehicles and hybrid vehicles. That is, in addition to functioning as a motor that generates driving torque corresponding to the power supplied when electricity is applied, it also functions as a generator that converts a portion of the power of the output shaft into electricity as the output shaft is rotated along with it. Specifically, it is composed of AC motors such as synchronous motors and induction motors.

[0017] In the example shown in Figure 1, the first motor 2 is positioned on the lower side in the vertical direction and on the front side of the vehicle. The output shaft of the engine 1 and a power split mechanism (not shown) are located on the same axis as the rotational axis of the first motor 2. This power split mechanism is a differential mechanism that connects the engine 1, the first motor 2, and the output gear 4 so as to be differentially rotatable, and is composed of, for example, a single-pinion type planetary gear mechanism. The engine 1 is connected to the carrier of the power split mechanism, the first motor 2 is connected to the sun gear of the power split mechanism, and the output gear 4 is connected to the ring gear of the power split mechanism.

[0018] Therefore, by generating a reaction torque in the first motor 2 corresponding to the torque input from the engine 1 to the power split mechanism, a portion of the torque from the engine 1 is transmitted to the output gear 4. When the reaction torque is generated in the first motor 2 in this way, the first motor 2 functions as a motor or as a generator, depending on the direction of rotation of the first motor 2. For this reason, MG power lines 5 for supplying power to the first motor 2 or outputting the power generated by the first motor 2 are connected to the first motor 2. Note that the first motor 2 shown in Figure 1 is a three-phase AC motor, so three MG power lines 5 corresponding to the U phase, V phase, and W phase are connected to the first motor 2.

[0019] A countershaft (not shown) is provided parallel to the rotational axis of the first motor 2. Specifically, the countershaft is located above the rotational axis of the first motor 2 in the vertical direction and at the rear in the longitudinal direction of the vehicle. A counter-driven gear 6 that meshes with the output gear 4 is attached to one end of this countershaft, and a counter-drive gear 7, which has a smaller diameter than the counter-driven gear 6, is attached to the other end of the countershaft.

[0020] Then, the ring gear 9 of the differential gear unit 8 meshes with the counter drive gear 7, and a pair of drive shafts 10 are connected to the differential gear unit 8. For the sake of convenience, in FIG. 2, the power split mechanism, the differential gear unit 8, etc. are shown as a transaxle (T / A) 11.

[0021] Also, a second motor 3 is provided parallel to the rotation center axis of the first motor 2 and the rotation center axis of the countershaft. Specifically, the second motor 3 is provided above the rotation center axis of the countershaft in the vertical direction and behind in the longitudinal direction of the vehicle. A drive gear 12 is attached to the output shaft of the second motor 3, and the drive gear 12 meshes with the counter driven gear 6. Therefore, the output torque of the second motor 3 can be added to the torque transmitted from the engine 1 to the counter driven gear 6.

[0022] This second motor 3 functions as a motor when supplied with the electric power generated by the first motor 2 or the electric power of the power storage device, and functions as a generator when generating the braking force of the vehicle. Therefore, similar to the first motor 2, an MG power line 5 for supplying power to the second motor 3 or outputting the electric power generated by the second motor 3 is connected to the second motor 3. Since the second motor 3 shown in FIG. 1 is also a three-phase alternating current type motor similar to the first motor 2, three MG power lines 5 corresponding to the U phase, V phase, and W phase are connected to the second motor 3. The above-mentioned MG power line 5 corresponds to the "first power line" in the embodiment of this invention.

[0023] Each of the motors 2, 3 and the transaxle 11 described above is housed in the same case 13. An opening 14 is formed on the side of the motors 2, 3 in the vehicle width direction in the case 13 for inserting each of the motors 2, 3 and the transaxle 11 and fixing each of the motors 2, 3 and the transaxle 11. That is, the shape of the opening 14 is a shape corresponding to the shape of each of the motors 2, 3 and the shape of each member constituting the transaxle 11.

[0024] A rear cover 15 is provided to close the opening 14. That is, after housing each motor 2,3 and the transaxle 11 in the case 13, the rear cover 15 is attached to the case 13. The outer dimensions of this rear cover 15 are formed to be larger than the opening 14, and the outer periphery of the rear cover 15 is fixed to the case 13 by a plurality of bolts 16. For convenience, only two bolts 16 are shown in Figure 1. This rear cover 15 corresponds to the "cover portion" in this embodiment of the invention.

[0025] The terminal block 17 to which the MG power line 5 described above is connected is positioned above the first motor 2 in the vertical direction. Specifically, the terminal block 17 is fixed slightly above the opening 14 on the inner wall surface of the case 13. In other words, it is located on the rear cover 15 side in the vehicle width direction.

[0026] As shown in Figure 3, the terminal block 17 is provided with lower terminals 17a that are connected to the MG power lines 5. Specifically, six lower terminals 17a are formed in a row along the side wall surface of the case 13. These lower terminals 17a extend outwards to the opening 14, and each MG power line 5 is fixed to these lower terminals 17a by bolts 18. In other words, the MG power lines 5 and the lower terminals 17a are fixed together by bolts 18 before the rear cover 15 is installed.

[0027] A power converter 19, including an inverter, is positioned horizontally alongside the terminal block 17. Specifically, the power converter 19 is positioned such that a portion of its lower side is aligned horizontally with the terminal block 17 and covers the upper end of the second motor 3. An opening 20 for inserting the power converter 19 is formed at the upper end of the case 13, and the power converter 19 is inserted through this opening 20 and then fixed to the case 13. After fixing the power converter 19 to the case 13, the opening 20 is closed by attaching the upper cover 21 to the case 13.

[0028] The power conversion device 19 described above includes an inverter that converts DC power output from a power storage device (not shown) into AC power and outputs it to each motor 2, 3, and also converts the AC power generated by each motor 2, 3 into DC power and supplies it to the power storage device. Power lines (hereinafter referred to as INV power lines) 22 are provided to connect the inverter and the motors 2, 3, and the INV power lines 22 are connected to a terminal block 17. In other words, six MG power lines 5 and six INV power lines 22 are connected via the terminal block 17. These INV power lines 22 correspond to the "second power lines" in this embodiment of the invention.

[0029] Specifically, as shown in Figure 3, the terminal block 17 is provided with upper terminals 17b, and the INV power line 22 and the upper terminals 17b are fixed together by bolts 23. In other words, six upper terminals 17b are formed in a row along the side wall surface of the case 13. Therefore, service holes 24 are formed in the side wall surface of the case 13 for inserting a tool (e.g., a screwdriver) to tighten the bolts 23.

[0030] This service hole 24 is a through-hole that is spaced a predetermined distance from the opening 14 and has a predetermined length along the periphery of the opening 14. In other words, the service hole 24 is formed outside the outer edge of the rear cover 15.

[0031] Therefore, as shown in Figure 3, the upper terminals 17b are positioned facing the service hole 24, and the INV power lines 22 are fixed to each upper terminal 17b by bolts 23. After the INV power lines 22 and the upper terminals 17b are fixed, the service hole 24 is closed by a cover (not shown).

[0032] As described above, the upper terminal 17b is provided facing the service hole 24, and the lower terminal 17a is provided facing the opening 14. In other words, the terminal block 17 is positioned opposite the inner surface of the portion of the case 13 between the service hole 24 and the opening 14, that is, the inner surface of the portion that the outer edge of the rear cover 15 abuts against. Therefore, the bolts 16 that fasten the rear cover 15 and the case 13 are provided on both sides of the terminal block 17.

[0033] This is to prevent the tip of the bolt 16 from coming into contact with the terminal block 17, as the effective screw length required to secure the rear cover 15 would be longer than the thickness of the case 13. Alternatively, to prevent the projection from coming into contact with the terminal block 17, a projection is formed on the inside of the case 13 to ensure the effective screw length of the female thread.

[0034] As described above, forming the service hole 24 results in a narrow width between the opening 14 and the service hole 24, leading to low rigidity. Furthermore, the rear cover 15 cannot be fixed to this low-rigidity area with bolts 16. Therefore, as shown in Figure 2, a flange portion 25 is formed along the outer edge of the rear cover 15 to increase its rigidity.

[0035] Figure 4 is a perspective view illustrating an example of the configuration of the flange portion 25. As shown in Figure 4, the flange portion 25 is formed in an L-shape when viewed from above. Specifically, in the longitudinal direction of the vehicle, the flange portion 25 is formed in the area corresponding to the central part of the service hole 24, starting from the front end of the service hole 24. Furthermore, the flange portion 25 is configured such that the flange height is lower on the front side of the vehicle and higher on the rear side. The upper surface of the flange portion 25 is formed as a smooth surface, and predetermined model numbers, such as the model numbers of each motor 2 and 3 and the unit, are engraved on this upper surface. In other words, the upper surface of the flange portion 25 serves as a base surface for indicating the model number (serial number). The upper surface of the flange portion 25 is not limited to engraved model numbers; a sticker may also be attached to indicate the model number, and the means of indicating the model number are not limited. In Figure 4, the area where the model number is indicated is hatched. Alternatively, as shown in Figure 4, the case 13 and the rear cover 15 may be fixed together with bolts 16 on the lower side of the flange portion 25, that is, in a position where the terminal block 17 is not provided inside the case 13.

[0036] As described above, by housing the motors 2, 3, transaxle 11, and power converter 19 in a single case 13, the drive unit, which integrates the motors 2, 3, transaxle 11, and power converter 19, can be miniaturized. Furthermore, by configuring the drive unit in this way, a service hole 24 is formed for inserting a tool to fix the INV power line 22 and the upper terminal 17b, and a flange portion 25 having a predetermined length along the service hole 24 is formed on the rear cover 15. Therefore, even when the rear cover 15 and the case 13 are fixed with bolts 16 while avoiding the terminal block 17, the rigidity of the portion of the rear cover 15 between the bolts 16 can be increased. As a result, because the flange portion 25 of the rear cover 15 is located near the service hole 24, even if vibrations generated when the motors 2, 3 are driven, power is transmitted via the transaxle 11, or the power converter 19 is activated are transmitted to the case 13, vibrations of the wall surface near the service hole 24 can be suppressed, and the generation of abnormal noises such as radiated noise can be suppressed.

[0037] Furthermore, by printing the model numbers of motors 2, 3, etc., on the upper surface of the flange portion 25, there is no need to separately provide a base for printing the model numbers on other parts of the case 13 or rear cover 15. In other words, since the flange portion 25 serves both to improve the rigidity of the rear cover 15 and as a base for printing the model numbers, the drive unit can be made smaller.

[0038] Furthermore, the flange portion in this embodiment of the invention is not limited to being provided on the rear cover, as it only needs to be able to suppress displacement at a location with low rigidity near the service hole. Specifically, the flange portion may be provided on the side wall surface of the case, in the portion between the service hole and the opening. In other words, the flange portion may be provided to improve the rigidity of the portion between the service hole and the opening. In that case, a notch can be formed in the rear cover along the outer shape of the flange portion, and the rear cover can be fixed to the case.

[0039] Furthermore, the electric vehicle in this embodiment of the invention is not limited to the hybrid vehicle described above. The engine may be a series hybrid vehicle used solely to drive a generator, a parallel hybrid vehicle equipped with only one motor to adjust the torque transmitted from the engine to the drive wheels, or an electric vehicle equipped with only a motor.

[0040] Furthermore, the drive unit in this embodiment of the invention may consist of a motor and a power converter housed in a case, and components such as a transaxle for transmitting torque from the motor to the drive wheels may be housed in a separate case. [Explanation of symbols]

[0041] 2,3 motors 5 MG power line 11 transaxle 13 cases 14,20 Opening 15 Rear cover 16, 18, 23 bolts 17 Terminal block 17a Lower terminal 17b Upper terminal 19 Power converter 22 INV power line 24 Service Holes 25 Flange section

Claims

1. A drive unit for an electric vehicle, comprising a motor as a driving force source, a power conversion device for controlling the power supplied to the motor, and a terminal block for connecting the first power line of the motor and the second power line of the power conversion device, housed in a case, The case is equipped with a cover portion that is attached to the side wall surface, The cover portion is fixed to the case by a plurality of bolts along its outer edge. The terminal block is provided facing the inner surface of the side wall of the case, including the portion that the outer edge of the cover portion abuts against. A service hole is formed in the side wall surface of the case, outside the outer peripheral edge of the cover portion and facing the terminal block, for inserting a tool to fix the first power line or the second power line to the terminal block. A flange portion having a predetermined length along the outer edge of the cover portion is formed between the service hole and the outer edge of the cover portion in the case, or on the outer edge of the cover portion. The flange portion has a base surface for indicating a predetermined model, including the motor model. A drive unit for an electric vehicle characterized by the following features.

2. A drive unit for an electric vehicle according to claim 1, The terminal block and the power converter are positioned above the motor in the vertical direction. A drive unit for an electric vehicle characterized by the following features.

3. A drive unit for an electric vehicle according to claim 1, The terminal block and the power converter are arranged side by side in the horizontal direction. A drive unit for an electric vehicle characterized by the following features.

4. A drive unit for an electric vehicle according to any one of claims 1 to 3, The case has an opening that is closed by the cover portion. The flange portion is provided between the service hole and the opening. A drive unit for an electric vehicle characterized by the following features.

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