Transmission device for vehicles

Abstract

Transmission device provided between a drive shaft (39) coupled to a drive wheel (19) and a motor shaft (55) coupled to a traction motor (16), wherein the transmission device (12) comprises the following: - a first engagement mechanism (60) for switching, using operating oil, a first power transmission path provided between the drive shaft (39) and the motor shaft (55) between a power transmission state and a power blocking state; - a second engagement mechanism (61) for switching, using operating oil, a second power transmission path provided between the drive shaft (39) and the motor shaft (55) between a power transmission state and a power blocking state; - an oil passage switching valve (83) provided between an oil pressure supply source (81) and the first and second engagement mechanisms (60, 61), and switching between a state in which operating oil is directed to the first engagement mechanism (60) and a state in which the operating oil is directed to the second engagement mechanism (61); and - an output control valve (82) provided between the oil pressure supply source (81) and the oil passage changeover valve (83) and switching between a connected state in which operating oil can pass from the oil pressure supply source (81) through the output control valve (82) to the oil passage changeover valve (83) and a blocked state in which the operating oil is blocked from the oil pressure supply source (81) to the oil passage changeover valve (83) and is discharged through the oil passage changeover valve (83); wherein the oil passage switching valve (83) is designed in such a way as to ensure that operating oil is not supplied to the first engagement mechanism (60) and the second engagement mechanism (61) simultaneously.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The present invention relates to a transmission device for vehicles, which is provided between a drive shaft coupled to a drive wheel and a motor shaft coupled to a traction motor. 2. Description of the relevant state of the art

[0002] Vehicles with automatic transmissions or similar systems incorporate a variety of clutch and brake mechanisms (e.g., Japanese patent application publication JP-A-2007-270 954). These clutch and brake mechanisms require an engagement control system that prevents a locking situation, in which transmission cables with different gear ratios are engaged simultaneously.

[0003] In a hybrid vehicle that uses both an internal combustion engine and a traction motor as drive sources, or in an electric vehicle that uses a traction motor as a drive source, over-revving of the traction motor must be prevented in order to suppress an induced voltage of the traction motor and thereby protect an inverter.

[0004] By installing a gearbox between the drive shaft and the traction motor, the traction motor's speed can be reduced during high-speed driving, thus preventing over-revving. The over-revving gearbox is further equipped with a variety of clutch and brake mechanisms, making it essential to incorporate a locking mechanism.

[0005] Document DE 10 2007 053 784 A1 describes a method and a device for controlling an electromechanical transmission during a shifting operation, which includes detecting a fault in a disengaging clutch. The method includes deactivating a disengaging torque transmission clutch, monitoring the slippage of the disengaging torque transmission clutch, and limiting changes in the operation of an electric motor functionally connected to the transmission until the slippage of the disengaging torque transmission clutch exceeds a threshold value. Limiting changes in the operation of the electric motor includes limiting the drive torque of the electric motor, specifically limiting the time-dependent change in the drive torque and limiting the magnitude of the drive torque.The limit of the change in the operation of the electric motor is reached when the slip of the outgoing torque transmission clutch exceeds the threshold value.

[0006] Document DE 695 04 257 T2 describes a control unit for a hydraulic transmission. It features a changeover valve on the upstream side of solenoid valves for hydraulic engagement elements. The changeover valve is forced into the closed position by the hydraulic oil pressure of a multitude of hydraulic engagement elements associated with speed changes. In the event of a failure where three or more of the hydraulic engagement elements are engaged simultaneously, the changeover valve switches to the closed position to reduce the hydraulic oil pressure in the hydraulic engagement elements on the downstream side of the changeover valve, thus preventing simultaneous engagement. In the closed position, hydraulic oil pressure at a predetermined level is introduced into the changeover valve via an oil channel.This prevents the changeover valve from chattering, even when the hydraulic oil pressure in the hydraulic intervention elements is reduced.

[0007] Document US 2006 / 0116231A1 describes a transmission power transfer mechanism for a hybrid electric vehicle in which multiple power flow paths are established between a motor and the vehicle's drive wheels, as well as between an electric motor and the vehicle's drive wheels. At least one of the power flow paths is characterized by at least two gear ratios. BRIEF DESCRIPTION OF THE INVENTION

[0008] One objective of the present invention is to prevent blockage in a transmission device for vehicles.

[0009] The problem underlying the invention is solved by a transmission device with the features of independent claim 1. Advantageous embodiments of the invention are specified in dependent claims 2 to 7.

[0010] In the transmission device according to the present invention, the oil passage switching valve is switched by a pilot pressure from a solenoid valve.

[0011] In the transmission device according to the present invention, the output control valve is switched by a pilot pressure from a solenoid valve.

[0012] In the transmission device according to the present invention, the oil pressure supply source is an electric pump, and the output control valve is switched by the operating oil from the electric pump.

[0013] In the transmission device according to the present invention, the electric pump is driven by a traction motor.

[0014] In the transmission device according to the present invention, the first and second power transmission paths are formed by a single planetary gear.

[0015] According to the present invention, operating oil is distributed by the oil passage switching valve to one of the first engagement mechanism and the second engagement mechanism, thus preventing a blockage in which the first engagement mechanism and the second engagement mechanism are both engaged.

[0016] Furthermore, the output control valve is located on the upstream side of the oil passage changeover valve, thus enabling the output control valve to be switched to the blocked position even if control of the oil passage changeover valve becomes impossible. Consequently, over-revving of the traction motor can be prevented, and the electrical system can be protected in this way. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings show: Fig. 1 a schematic representation of a hybrid vehicle; Fig. 2. A schematic outline diagram illustrating the internal construction of a drive unit installed in the hybrid vehicle; Fig. 3 an enlarged sectional view of a gear device provided in the drive unit; Fig. 4A a circuit diagram to explain a hydraulic control circuit provided in the transmission device; Fig. 4B a simplified circuit diagram of the hydraulic control circuit; Fig. 5A a circuit diagram to illustrate an operating state in which a high clutch is engaged and a low brake is released; Fig. 5B a circuit diagram to illustrate an operating state in which the low brake is applied and the high clutch is disengaged; and Fig. 5C a circuit diagram to illustrate an operating state in which both the high clutch and the low brake are released; Fig. 6 a circuit diagram to illustrate a hydraulic control circuit provided in a transmission device according to a further embodiment of the present invention; Fig. 7 a fragmentary outline schematic representation to illustrate a drive unit with an oil pump driven by a motor / generator; and Fig. 8 a fragmentary, outline-like schematic representation to illustrate a drive unit which is provided with a gear device according to a further embodiment of the present invention. DESCRIPTION OF PREFERRED EXECUTION EXAMPLES

[0018] In the following, exemplary embodiments of the present invention are described with reference to the drawings. Fig. Figure 1 shows a schematic representation of a hybrid vehicle 10. Fig. Figure 2 shows an outline representation to illustrate the internal construction of a drive unit 11 installed in the hybrid vehicle 10. A transmission device 12 for vehicles according to an embodiment of the present invention is integrated into the drive unit 11.

[0019] As in Fig. As shown in Figure 1, the drive unit 11 is mounted longitudinally in a vehicle body from an engine compartment 13 to a floor tunnel 14. An internal combustion engine 15 is integrated into one end of the drive unit 11, and a motor / generator (traction motor) 16 is integrated into another end of the drive unit 11. A continuously variable transmission 17, a differential mechanism 18, etc., are integrated into the drive unit 11 such that power from the internal combustion engine and power from the electric motor are transmitted from the differential mechanism 18 to a drive wheel 19.

[0020] Furthermore, an inverter 21 is provided between a high-voltage battery 20 and the motor / generator 16, which serves as an AC motor to supply electrical energy to the motor / generator 16. The inverter 21 is formed by a switching element or the like, and DC energy from the high-voltage battery 20 is converted via the inverter 21 into AC energy for the motor / generator 16. It should be noted that when the motor / generator 16 is used as a generator, AC energy from the motor / generator 16 is converted via the inverter 21 into DC energy for the high-voltage battery 20.

[0021] As in Fig. As shown in Figure 2, a gearbox housing 22 is attached to the internal combustion engine 15, and the continuously variable transmission 17 is housed within the gearbox housing 22. The continuously variable transmission 17 includes a primary shaft 23, which is driven by the internal combustion engine 15, and a secondary shaft 24, which is parallel to the primary shaft 23. A primary pulley 25 is provided on the primary shaft 23, and the primary pulley 25 includes a fixed disc 25a and a movable disc 25b. Operating oil chambers 26a, 26b are formed on the side of a rear surface of the movable disc 25b, and the pulley groove width can be varied by regulating the pressure in the operating oil chambers 26a and 26b.

[0022] A secondary pulley 27 is provided on the secondary shaft 24, and the secondary pulley 27 comprises a stationary disc 27a and a movable disc 27b. An operating oil chamber 28 is formed on the side of a rear surface of the movable disc 27b, and the pulley groove width can be varied by regulating the pressure in the operating oil chamber 28. Furthermore, a drive chain 29 is guided around the primary pulley 25 and the secondary pulley 27. By varying the groove width of the pulleys 25 and 27 to vary the rotational diameter of the drive chain 29, the primary shaft 23 can be continuously displaced relative to the secondary shaft 24.

[0023] A torque converter 31 and a forward / reverse switching mechanism 32 are provided between a crankshaft 30 and the primary shaft 23 to transmit the power of the internal combustion engine to the continuously variable transmission 17. The torque converter 31 includes a pump impeller 33 coupled to the crankshaft 30 and a turbine impeller 35, which is arranged opposite the pump impeller 33 and coupled to a turbine shaft 34.

[0024] The forward / reverse switching mechanism 32 includes a planetary gear set 36 of the double-pinion type, a forward clutch 37, and a reverse brake 38. By controlling the forward clutch 37 and the reverse brake 38, a power transmission path of the internal combustion engine can be switched, and consequently, the direction of rotation of the primary shaft 23 can be reversed. Furthermore, a transmission output shaft 39 is housed in the transmission casing 22 parallel to the secondary shaft 24 as a drive shaft, and the transmission output shaft 39 is coupled to the secondary shaft 24 via a transmission linkage 40.

[0025] Furthermore, a pinion 41 is fixed to an end region of the transmission output shaft 39, and the pinion 41 meshes with a ring gear 42 of the differential mechanism 18. Thus, the continuously variable transmission 17 and the differential mechanism 18 are coupled via the transmission output shaft 39 in such a way that the combustion engine power output is transmitted from the continuously variable transmission 17 via the transmission output shaft 39 to the differential mechanism 18.

[0026] Furthermore, a motor housing 50 is attached to the gearbox housing 22, and the motor / generator 16 is housed in the motor housing 50. The motor / generator 16 includes a stator 51 fixed to the motor housing 50 and a rotor 52, which is freely rotatable inside the stator 51. The gearbox 12 and a gear train 53 are arranged between the motor / generator 16 and the gearbox output shaft 39 such that the motor power is transmitted to the drive wheel 19 via the gearbox 12 and the gear train 53.

[0027] The transmission device 12 includes a planetary gear set 54, and the planetary gear set 54 is formed from a sun gear 56 coupled to a motor shaft 55 extending away from the rotor 52, a carrier 57 coupled to the transmission output shaft 39 via the transmission linkage 53, and a ring gear 59 meshing with a pinion 58 of the carrier 57. It should be noted that the pinion 58 of the carrier 57 meshes with both the sun gear 56 and the ring gear 59.

[0028] Furthermore, a high-engagement clutch 60, which serves as the first engagement mechanism and can be switched between an engaged state and a disengaged state, is provided between the sun gear 56 and the carrier 57. A low-engagement brake 61, which serves as the second engagement mechanism and can be switched between an engaged state and a disengaged state, is also provided between the ring gear 59 and the motor housing 50.

[0029] Fig. Figure 3 shows an enlarged sectional view of the gear unit 12 provided in the drive unit 11. As in Fig. As shown in Figure 3, the high-speed coupling 60 provided in the transmission device 12 includes a coupling hub 62 fixed on the motor shaft 55 and a coupling drum 63 coupled to a drive gear 53a of the transmission train 53. A plurality of friction discs 64a are attached to the coupling hub 62, and a plurality of friction discs 64b are attached to the coupling drum 63.

[0030] Furthermore, a piston element 65 is housed in the clutch drum 63, and a clutch oil chamber 66 is formed by the clutch drum 63 and the piston element 65. When operating oil is supplied to the clutch oil chamber 66, the piston element 65 is forced outwards by oil pressure, and as a result, the friction discs 64a and 64b are pressed against each other, so that the high-speed clutch 60 is brought into the engaged state. When, on the other hand, the operating oil is discharged from the clutch oil chamber 66, the piston element 65 is pushed back by a spring element 67, and thereby the engagement between the friction discs 64a and 64b is disengaged, so that the high-speed clutch 60 is brought into the disengaged state.

[0031] By engaging the high-speed clutch 60 in this manner, the carrier 57 and the sun gear 56 can be caused to rotate integrally, thus allowing the carrier speed to be matched to the motor speed. In other words, engaging the high-speed clutch 70 establishes the first power transmission path for transferring the motor power from the sun gear 56 to the carrier 57 via the high-speed clutch 60.

[0032] The low-speed brake 61 provided in the transmission device 12 comprises a brake hub 70 provided on the ring gear 59 and a brake drum 71 provided in the motor housing 50. A plurality of friction discs 72a are attached to the brake hub 70, and a plurality of friction discs 72b are attached to the brake drum 71. Furthermore, a piston element 73 is housed in the brake drum 71, and a brake oil chamber 74 is formed by the brake drum 71 and the piston element 73.

[0033] When operating oil is supplied to the brake oil chamber 74, the piston element 73 is pushed outwards by oil pressure, and consequently the friction discs 72a and 72b are pressed against each other, so that the low-pressure brake 61 is brought into the applied state. When, on the other hand, the operating oil is discharged from the brake oil chamber 74, the piston element 73 is pushed back by a spring element 75, and thereby the engagement between the friction discs 72a and 72b is released, so that the low-pressure brake 61 is brought into the released state.

[0034] By engaging the low-speed brake 61 in this manner, the ring gear 59 is locked to the motor housing 50, thus allowing the motor speed to be increased beyond the carrier speed. In other words, engaging the low-speed brake 61 activates the second power transmission path for transferring motor power from the sun gear 56 via the pinion 59 to the carrier 57.

[0035] As described above, by engaging the low-speed brake 61 and disengaging or releasing the high-speed clutch 60, the ring gear 59 is locked to the motor housing 50, thus allowing the motor speed to be increased beyond the carrier speed. Conversely, by engaging the high-speed clutch 60 and releasing the low-speed brake 61, the carrier 57 can be caused to rotate integrally with the sun gear 56, thus allowing the carrier speed to be matched to the motor speed.

[0036] By controlling the transmission device 12 in this manner, the motor speed can be switched in two stages, thereby reducing the maximum speed of the motor / generator 16. In other words, at low speeds, the low-speed brake 61 is engaged and the high-speed clutch 60 is disengaged, while at high speeds, the high-speed clutch 60 is engaged and the low-speed brake 61 is disengaged. It should be noted that at high speeds, the motor / generator 16 can be decoupled from the transmission output shaft 39 by disengaging both the high-speed clutch 60 and the low-speed brake 61.

[0037] When both the high-speed clutch 60 and the low-speed brake 61 are engaged, power transmission paths with different gear ratios are simultaneously brought into the power transmission state, and as a result, the transmission output shaft 39 and the engine shaft 55 are suddenly caused to stop their rotation. To prevent such a blockage, a hydraulic control circuit 80 is provided to ensure that operating oil is not supplied to the high-speed clutch 60 and the low-speed brake 61 simultaneously. Fig. Figure 4A shows a circuit diagram to explain the hydraulic control circuit 80 provided in the transmission device 12, and Fig. Figure 4B shows a simplified circuit diagram of the hydraulic control circuit 80.

[0038] As in the Fig. 4A and Fig. As shown in Figure 4B, an output control valve 82 is provided between an oil pump 81, which serves as the oil pressure supply source driven by the motor 15, and the clutch oil chamber 66 and the brake oil chamber 74. The output control valve 82 can be switched between a connected state, in which operating oil from the oil pump 81 can pass through the output control valve 82, and a blocked state, in which the passage of operating oil from the oil pump 81 is blocked. Furthermore, an oil passage switching valve 83 is provided between the output control valve 82 and the clutch oil chamber 66 and the brake oil chamber 74.

[0039] The oil passage switching valve 83 can be switched between a clutch engagement state, in which operating oil is directed from the output control valve 82 to the clutch oil chamber 66, and a brake engagement state, in which the operating oil is directed from the output control valve 82 to the brake oil chamber 74.

[0040] Furthermore, an oil pressure sensor 85 is provided in an oil supply passage for guiding the operating oil from the output control valve 82 to the oil passage changeover valve 83, and an oil pressure signal is output from the oil pressure sensor 85 to a control unit 86.

[0041] The output control valve 82 has a housing 87 and a spool valve stem 88, which is freely movably mounted in the housing 87. The housing 84 has an inlet port 87a, an outlet port 87b, and a discharge port 87c. An oil supply passage 89, extending away from the oil pump 81, is connected to the inlet port 87a; an oil supply passage 84, leading to the oil passage changeover valve 83, is connected to the outlet port 87b; and an outlet oil passage 90 is connected to the discharge port 87c.

[0042] Furthermore, a spring element 91 is integrated into one end of the spool valve stem 88 of the output control valve 82 to actuate the spool valve stem 88, and a pilot pressure chamber 92 is formed at another end of the spool valve stem 88. A pilot port 87d, which is connected to the pilot pressure chamber 92, is formed in the housing 87, and a pilot pressure passage 93 is connected to the pilot port 87d. A solenoid valve 94, controlled by the control unit 86, is connected to the pilot pressure passage 93, and a pilot pressure regulated by the solenoid valve 94 is supplied to the pilot pressure chamber 92.

[0043] When operating oil is supplied to the pilot pressure chamber 92, the spool valve stem 88 moves against a spring force in the direction of arrow A, and as a result, the output control valve 82 is switched to a closed state in which the inlet port 87a and the outlet port 87b are blocked. Conversely, when operating oil is discharged from the pilot pressure chamber 92, the spool valve stem 88 is moved by the spring force in the direction of arrow B, and as a result, the output control valve 82 is switched to a connected state in which the inlet port 87a and the outlet port 87b are connected.

[0044] Furthermore, the oil passage changeover valve 83 comprises a housing 95 and a spool valve stem 96, which is freely movably mounted in the housing 95. An inlet port 95a is formed in the housing 95, and the oil supply passage 84, extending away from the outlet control valve 82, is connected to the inlet port 95a. A pair of outlet ports 95b and 95c are also formed in the housing 95. A clutch oil passage 97, which is connected to the clutch oil chamber 66, is connected to one outlet port 95b, and a brake oil passage 98, which is connected to the brake oil chamber 74, is connected to the other outlet port 95c.

[0045] Furthermore, a pair of outlet openings 95d and 95e are formed in the housing 95, and the outlet oil passages 99 and 100 are connected to the respective outlet openings 95d and 95e. A spring element 101 is integrated into one end of the spool valve stem 96 of the output control valve 82 to actuate the spool valve stem 96, and a pilot pressure chamber 102 is formed at the other end of the spool valve stem 96.

[0046] A pilot port 95f, connected to the pilot pressure chamber 102, is formed in the housing 95, and a pilot pressure passage 103 is connected to the pilot port 95f. A solenoid valve 104, controlled by the control unit 86, is connected to the pilot pressure passage 103, and a pilot pressure regulated by the solenoid valve 104 is supplied to the pilot pressure chamber 102. When operating oil is supplied to the pilot pressure chamber 102, the spool valve stem 96 moves against a spring force in the direction of arrow A, and as a result, the oil passage changeover valve 83 is switched to a brake engagement state in which the inlet port 95a is connected to the outlet port 95c.

[0047] If, on the other hand, the operating oil is discharged from the pilot pressure chamber 102, the slide valve stem 96 is moved by the spring force in the direction of arrow B, and as a result, the oil passage switching valve 83 is switched to a clutch engagement state in which the inlet opening 95a is connected to the outlet opening 95b.

[0048] The following describes the operating conditions of the hydraulic control circuit 80. Fig. Figure 5A shows a circuit diagram to illustrate an operating state in which the high clutch 60 is engaged and the low brake 61 is released. Fig. Figure 5B shows an operating state in which the low brake 61 is engaged and the high clutch 60 is disengaged, and Fig. Figure 5C shows a circuit diagram to illustrate an operating state in which both the high clutch 60 and the low brake 61 are released.

[0049] As in Fig. As shown in Figure 5A, when the high-speed clutch 60 is engaged and the low-speed brake 61 is released, the pilot pressure supplied by the solenoid valve 94 to the output control valve 82 is blocked, thus switching the output control valve 82 to the engaged state. Furthermore, the pilot pressure supplied by the solenoid valve 104 to the oil passage changeover valve 83 is blocked, thus switching the oil passage changeover valve 83 to the clutch engagement state, in which operating oil is supplied to the clutch oil chamber 66.

[0050] The operating oil delivered by the oil pump 81 is thus supplied by the output control valve 82 via the oil passage switching valve 83 to the clutch oil chamber 66, so that the high clutch 60 is switched into the engaged state. At this point, the oil passage switching valve 83 connects the brake oil passage 98 with the outlet oil passage 100, and thus the operating oil in the brake oil chamber 74 is delivered via the oil passage switching valve 83, so that the low brake 61 is reliably held in the disengaged state.

[0051] As in Fig. As shown in Figure 5B, when the low-pressure brake 61 is applied and the high-pressure clutch 60 is released, the pilot pressure supplied by the solenoid valve 94 to the output control valve 82 is blocked, so that the output control valve 82 is switched to the connected state. Furthermore, the pilot pressure is supplied by the solenoid valve 104 to the oil passage changeover valve 83, and thus the oil passage changeover valve 83 is switched to the brake engagement state, in which operating oil is supplied to the brake oil chamber 74.

[0052] The operating oil delivered by the oil pump 81 is thus supplied to the brake oil chamber 74 by the output control valve 82 via the oil passage switching valve 83, and as a result, the low-pressure brake 61 is switched into the engagement state.

[0053] At this point, the oil passage switching valve 83 connects the clutch oil passage 97 with the outlet oil passage 99, and thus the operating oil in the clutch oil chamber 66 is discharged via the oil passage switching valve 83, so that the high clutch 60 is reliably held in the disengaged state.

[0054] As further in Fig. As shown in Figure 5C, when both the high clutch 60 and the low brake 61 are released, pilot pressure is supplied to the output control valve 82 by the solenoid valve 94, thus switching the output control valve 82 into the blocked state. As a result, the operating oil from the oil pump 81 is blocked by the output control valve 82, and in this way the supply of operating oil to both the clutch oil chamber 66 and the brake oil chamber 74 can be blocked.

[0055] At this point, the output control valve 82 connects the oil supply passage 84 with the outlet oil passage 90, and thus both the high clutch 60 and the low brake 61 can be reliably kept in the disengaged state regardless of the operating state of the oil passage switching valve 83.

[0056] In other words, in the situation depicted in the drawing, the brake oil passage 98 and the outlet oil passage 100 are connected via the oil passage changeover valve 83, and thus the operating oil in the brake oil chamber 74 is discharged via the oil passage changeover valve 83. The clutch oil passage 97 and the oil supply passage 84 are connected via the oil passage changeover valve 83, and thus the operating oil in the clutch oil chamber 66 is directed via the oil passage changeover valve 83 to the output control valve 82.

[0057] The output control valve 82 connects the oil supply passage 84 with the outlet oil passage 90, and thus the operating oil in the clutch oil chamber 66 is discharged by the oil passage switching valve 83 via the output control valve 82. This allows the high-speed clutch 60 to be reliably switched to the disengaged state.

[0058] As described above, operating oil is distributed by the oil passage switching valve 83 to one of the clutch oil chambers 66 and the other to the brake oil chamber 74, thus ensuring that operating oil is never supplied to both chambers simultaneously. Blockage is therefore reliably prevented.

[0059] Furthermore, the output control valve 82 is provided on an upstream side of the oil passage switching valve 83, and thus even in a case where control of the oil passage switching valve 83 becomes impossible while the oil passage switching valve 83 is in the brake engagement state, the low brake 61 can be released by switching the output control valve 82 into the blocking state, and as a result, the occurrence of over-revving in the motor / generator 16 can be prevented.

[0060] In other words, the low-speed brake 61 can be reliably released even if a power supply failure occurs at the solenoid valve 104 for controlling the oil passage changeover valve 83 (so that the solenoid valve 104 is constantly ON), or if the oil passage changeover valve 83 becomes stuck in the brake engagement state due to foreign matter or the like, and over-revving of the motor / generator 16 during high-speed driving can be prevented. Consequently, a malfunction of the inverter 21 due to excessive induced voltage from the motor / generator 16 can be avoided.

[0061] Furthermore, even in a case where the control of the output control valve 82 becomes impossible while the output control valve 82 is in the connected state, the low brake 61 can be released by switching the oil passage changeover valve 83 into the clutch engagement state, and as a result, the occurrence of over-revving in the motor / generator 16 can be prevented.

[0062] In other words, the low-speed brake 61 can be reliably released even if a grounding fault occurs in the solenoid valve 94 for controlling the output control valve 82 (so that the solenoid valve 94 is constantly OFF) or if the output control valve 82 remains stuck in the connected state due to foreign matter or the like, thus preventing over-revving of the engine / generator 16 during high-speed driving.

[0063] Consequently, a malfunction of the inverter 21 due to excessive induced voltage from the motor / generator 16 can be avoided. It should be noted that a malfunction in the output control valve 82 is detected by comparing a control signal related to the solenoid valve 94 with the oil pressure signal from the oil pressure sensor 85.

[0064] In the hydraulic control circuit 80 described above, the output control valve 82 is switched by the pilot pressure from the solenoid valve 94, however, the present invention is not limited to this, and the output control valve 82 can also be switched by the operating oil supplied by the oil pump 81.

[0065] Fig. Figure 6 shows a circuit diagram to illustrate a hydraulic control circuit 110, which is provided in a transmission device according to a further embodiment of the present invention. It should be noted that elements which the in Fig. The four elements shown are similar, are labelled with the same reference symbols, and no further description of these elements is provided.

[0066] As in Fig. As shown in Figure 6, an electric motor 112 is integrated into an oil pump 111, which serves as the oil pressure supply source, with the oil pump 111 functioning as the electric pump driven by the electric motor 112. Furthermore, an output control valve 113, located between the oil pump 111 and the oil passage changeover valve 83, has a housing 114 and a spool valve stem 88, which is freely movably mounted in the housing 114.

[0067] The housing 114 has an inlet opening 114a, an outlet opening 114b, and a discharge opening 114c. The oil supply passage 89, extending away from the oil pump 111, is connected to the inlet opening 114a, the oil supply passage 84, leading to the oil passage changeover valve 83, is connected to the outlet opening 114b, and the discharge oil passage 90 is connected to the discharge opening 114c.

[0068] Furthermore, a pilot opening 114d is formed in the housing 114, which is connected to the pilot pressure chamber 92, and a pilot pressure passage 115, which branches off from the oil supply passage 89, is connected to the pilot opening 114d.

[0069] When operating oil is supplied to the pilot pressure chamber 92, the spool valve stem 88 moves against the spring force in the direction of arrow A, and consequently the output control valve 82 is switched to a connected state in which the inlet port 114a and the outlet port 114b are connected. Conversely, when operating oil is discharged from the pilot pressure chamber 92, the spool valve stem 88 is moved by the spring force in the direction of arrow B, and consequently the output control valve 113 is switched to a blocked state in which the inlet port 114a and the outlet port 114b are blocked.

[0070] In this configuration, operating oil is supplied to the pilot pressure chamber 92 by the oil pump 111 when the electric motor 112 is running, and consequently the output control valve 113 is switched to the open state. Conversely, when the operation of the electric motor 112 is stopped, the supply of operating oil from the oil pump 111 to the pilot pressure chamber 92 is interrupted, and thus the output control valve 113 is switched to the closed state.

[0071] This allows the output control valve 113 to be switched in conjunction with an operating state of the electric motor 112, and thus the solenoid valve 94 described above can be omitted, enabling a simplification of the hydraulic control circuit 110.

[0072] Furthermore, the in Fig. 6 hydraulic control circuit 110 the electric motor 112 to operate the oil pump 111, however the present invention is not limited thereto, and the oil pump 111 can also be operated using the motor / generator 16. Fig. Figure 7 shows a fragmentary outline representation to illustrate a drive unit 121 with an oil pump 120, which is driven by the motor / generator 16.

[0073] It should be noted that elements which are in Fig. Elements similar to those shown in section 1 are designated with the same reference symbols, and no further description of these elements is provided. As in Fig. As shown in Figure 7, the oil pump 120, which serves as the oil pressure supply source, is located adjacent to the motor / generator 16 in a rear end area of ​​the drive unit 121.

[0074] The oil pump 120 has an outer rotor 122 and an inner rotor 123, and a pump drive shaft 124 extending from the rotor 52 of the motor / generator 16 is coupled to the inner rotor 123. If the oil pump 120, driven by the motor / generator 16, is configured in this way, the special electric motor 112 for operating the oil pump is not required, and thus the hydraulic control circuit 110 can be simplified. It should be noted that, for example, an external gear oil pump can be used for the oil pump 120.

[0075] Furthermore, it should be noted that the transmission device 12 shown in the drawings is formed by the planetary gear 54, however, the present invention is not limited to this, and the transmission device 12 can also be formed by a transmission gear train or a gear with parallel shafts. Fig. Figure 8 shows a fragmentary outline representation to illustrate a drive unit 131 which is provided with a gear device 130 according to a further embodiment of the present invention.

[0076] It should be noted that elements which are in Fig. Elements similar to those shown in section 1 are designated with the same reference symbols, and no further description of these elements is provided. As in Fig. As shown in Figure 8, two drive gears 132a and 133a are provided to be freely rotatable on the motor shaft 55, and two driven gears 132b and 133b, which mesh with the drive gears 132a and 133a, are fixed on the transmission output shaft 39.

[0077] Furthermore, a high-engagement clutch 134, serving as a first engagement mechanism and capable of switching between an engaged state and a disengaged state, is provided between the drive gear 132a and the motor shaft 55. A low-engagement clutch 135, serving as a second engagement mechanism and capable of switching between an engaged state and a disengaged state, is also provided between the drive gear 133a and the motor shaft 55.

[0078] The high-speed clutch 134 and the low-speed clutch 135 have clutch hubs 136 and 137, which are fixed to the motor shaft 55, and clutch drums 138 and 139, which are coupled to the drive gears 132a and 133a. A plurality of friction discs 140 are fitted between the clutch hub 136 and the clutch drum 138, and a plurality of friction discs 141 are fitted between the clutch hub 137 and the clutch drum 139.

[0079] Furthermore, piston elements 142 and 143 are housed in the clutch drums 138 and 139, and clutch oil chambers 144 and 145 are formed by the clutch drums 138 and 139 and the piston elements 142 and 143. When operating oil is supplied to the clutch oil chamber 144, so that the high-speed clutch 134 is engaged, the first power transmission path for transmitting the engine power from the drive gear 132a via the high-speed clutch 134 to the driven gear 132b is switched into a power transmission state.

[0080] If operating oil is supplied to the clutch oil chamber 145 in such a way that the low-speed clutch 135 is switched into the engagement state, then the second power transmission path for transmitting the motor power from the drive gear 133a via the low-speed clutch 135 to the driven gear 133b is also switched into a power transmission state.

[0081] Even if the transmission device 130 is formed by a parallel-shaft type transmission, similar effects to those of the transmission device 12 described above can be achieved. It should be noted that in the case shown in the drawings, the high-speed clutch 134 and the low-speed clutch 135 are used, which are friction engagement mechanisms; however, the present invention is not limited to this, and a synchronous transmission mechanism can instead be provided for switching the transmission train to the power transmission state, wherein the synchronous transmission mechanism can be driven by a hydraulic actuating device.

[0082] The present invention is not limited to the embodiments described above, and various modifications to the invention can be made within its scope. Furthermore, the present invention is used in the preceding description in a hybrid vehicle 10; however, the present invention can also be used in an electric vehicle that uses only a traction motor as a drive source. Reference symbol list 10 Hybrid vehicles 11 Drive unit 12 Gearbox device 13 Engine compartment 14 ground tunnels 15 Internal combustion engine 16 Motor / Generator 17 gearboxes 18 Differential mechanism 19 drive wheel 20 batteries 21 Inverter 22 Gearbox housings 23 Primary shaft 24 Secondary shaft 25 Primary pulley 25a fixed disc 25b movable disc 26a Oil chamber 26b Oil chamber 27 Secondary pulley 27a fixed disc 27b movable disc 28 Operating oil chamber 29 Drive chain 30 Crankshaft 31 torque converters 32 Forward / reverse switching mechanism 33 Pump impeller 34 Turbine shaft 35 Turbine wheel 36 Gearbox train 37 Forward clutch 38 Reverse brake 39 Gearbox output shaft 40 Gearbox train 41 sprockets 42 Ring gear 50 engine housings 51 Stator 52 Rotor 53 Gearbox train 53a Drive gear 54 planetary gears 55 Motor shaft 56 Sun wheel 57 carriers 58 sprockets 59 Ring gear 60 High-coupling 61 Low brake 62 Clutch hub 63 Clutch drum 64a Friction disc 64b friction disc 65 Piston element 66 Clutch oil chamber 67 Spring element 70 Brake hub 71 Brake drum 72a Friction disc 72b friction disc 73 Piston element 74 Brake oil chamber 75 Spring element 80 hydraulic control circuit 81 Oil pump 82 Output control valve 83 Oil passage changeover valve 84 Oil supply passage 85 Oil pressure sensor 86 Control circuit 87 cases 87a Entrance opening 87b Exit opening 87c Exit opening 87d Input tax opening 88 Slide valve stem 89 Oil supply passage 90 Oil outlet passage 91 Spring element 92 Pilot pressure chamber 93 Pilot pressure passage 94 Solenoid valve 95 cases 95a Entrance opening 95b Exit opening 95c Exit opening 95d Exit opening 95e Exit opening 96 Slide valve stem 97 Clutch oil passage 98 Brake oil passage 99 Oil outlet passage 100 Outlet oil passage 101 Spring element 102 Pilot pressure chamber 103 Pilot pressure passage 104 Solenoid valve 110 hydraulic control circuit 111 Oil pump 112 Electric motor 113 Output control valve 114 cases 114a Entrance 114b Exit 114c Exit opening 114d Input tax opening 115 Pilot pressure passage 120 oil pump 121 Drive unit 122 Outer rotor 123 Inner rotor 124 Pump drive shaft 130 Gearbox device 131 Drive unit 132a Drive gear 132b driven gear 133a Drive gear 133b driven gear 134 High-coupling 135 Low-Clutch 136 Clutch hub 137 Clutch hub 138 Clutch drum 139 Clutch drum 140 friction discs 142 Piston element 143 Piston element 144 Clutch oil chamber 145 Clutch oil chamber

Claims

A transmission device provided between a drive shaft (39) coupled to a drive wheel (19) and a motor shaft (55) coupled to a traction motor (16), wherein the transmission device (12) comprises: - a first engagement mechanism (60) for switching, using operating oil, a first power transmission path provided between the drive shaft (39) and the motor shaft (55) between a power transmission state and a power blocking state; - a second engagement mechanism (61) for switching, using operating oil, a second power transmission path provided between the drive shaft (39) and the motor shaft (55) between a power transmission state and a power blocking state;- an oil passage changeover valve (83) provided between an oil pressure supply source (81) and the first and second engagement mechanisms (60, 61), and switching between a state in which operating oil is directed to the first engagement mechanism (60) and a state in which the operating oil is directed to the second engagement mechanism (61); and - an output control valve (82) provided between the oil pressure supply source (81) and the oil passage changeover valve (83), and switching between a connected state in which operating oil can pass from the oil pressure supply source (81) through the output control valve (82) to the oil passage changeover valve (83), and a blocked state in which the operating oil is blocked from the oil pressure supply source (81) to the oil passage changeover valve (83) and is discharged through the oil passage changeover valve (83);wherein the oil passage switching valve (83) is designed in such a way as to ensure that operating oil is not supplied to the first engagement mechanism (60) and the second engagement mechanism (61) simultaneously. Gearbox device according to claim 1, characterized in that the oil passage switching valve (83) is switched by a pilot pressure from a solenoid valve (104). Gearbox device according to claim 1 or 2, characterized in that the output control valve (82) is switched with a pilot pressure from a solenoid valve (94). Gearbox device according to claim 1 or 2, characterized in that the oil pressure supply source (111, 112) is an electric pump and that the output control valve (113) is switched with operating oil by the electric pump (111, 112). Gear unit according to claim 4, characterized in that the electric pump (111, 112) is driven by a traction motor (16). Gear unit according to one of claims 1 to 5, characterized in that the first and the second power transmission path are formed with a single planetary gear (54). Gear unit according to claim 6, wherein the first power transmission path transmits power of the traction motor (16) from a sun gear (56) connected to the motor shaft (55) to a carrier (57) via the first engagement mechanism (60), and wherein the second power transmission path transmits power of the traction motor (16) from the sun gear (56) to the carrier (57) via a pinion (59).

Images