JPH0117020B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vehicle power transmission device that transmits power from an engine to drive wheels via a multi-stage transmission. The running states of vehicles such as automobiles include acceleration, deceleration, cruising, and coasting, and when going down a steep slope, the vehicle runs while applying engine braking. Among these, acceleration, cruising, engine braking, etc. require operation of the engine, but deceleration and coasting are possible even without engine power, that is, even when the engine is idling. In the power transmission devices commonly used today, the engine output shaft is connected to the wheel drive shaft via a transmission mechanism equipped with a clutch and transmission, so engine power is not required during deceleration or coasting. Even if this is not done, the engine is still being driven by the reverse load from the drive wheels, causing the engine to rotate at an unnecessarily high speed and wasting fuel. In order to avoid such a situation, the transmission may be placed in a neutral position or the clutch may be disengaged during deceleration or coasting, but this operation becomes complicated and troublesome. Accordingly, the present invention is designed to avoid wasting fuel by automatically disconnecting the power transmission path of the transmission mechanism and idling the engine when the vehicle enters a coasting state while the vehicle is running, thereby enabling economical driving. It is an object of the present invention to provide a power transmission device for a vehicle in which engine braking can be obtained as needed. In order to achieve this object, the present invention provides a power transmission device for a vehicle that connects an output shaft of an engine and a wheel drive shaft via a multi-stage transmission, in which the output shaft of the engine and the input shaft of the multi-stage transmission are In order to automatically cut off the transmission of reverse load from the input shaft of the multi-stage transmission device to the engine output shaft when the vehicle enters a coasting state while the vehicle is running, A one-way clutch that transmits power only in the direction of the input shaft is provided in the power transmission path, and even when the vehicle is in the coasting state, the one-way clutch is bypassed and the reverse load is transmitted to the power transmission path. The present invention is characterized in that an on/off clutch capable of arbitrarily connecting/disconnecting power is disposed in parallel with the one-way clutch so that power can be transmitted from the input shaft of the multi-stage transmission to the engine output shaft at any time. Hereinafter, embodiments of the present invention will be explained with reference to the drawings. Fig. 1 shows a first embodiment of the vehicle power transmission device according to the present invention. In this embodiment, the power of the engine E is transmitted to its output shaft. 1 to a starting clutch C, a transmission control device Tc, a manual multi-stage transmission Tm having a transmission gear train G ₁ to G ₆ of 1 to 5 forward speeds and 1 reverse speed, a reduction gear device R, a differential gear mechanism D, and The signal is transmitted to drive wheels (not shown) via the wheel drive shaft A. The configuration of the transmission control device Tc will be explained with reference to FIG. 2. A one-way clutch 5 is interposed between the output shaft 2 of the starting clutch C and the input shaft 3 of the multi-stage transmission Tm. transmits power only from the output shaft 2 of the starting clutch to the input shaft 3 of the multi-stage transmission Tm in a certain direction of rotation, but does not transmit power in the opposite direction, and also connects the output shaft 2 and the input shaft A disconnection clutch 6 is provided between adjacent ends of the shaft 3 in parallel with the one-way clutch 5, and is capable of connecting and disconnecting power as desired.
The closing operation of the disconnection clutch 6 connects the input shafts 2 and 3, thereby allowing power to be transmitted from the input shaft 3 to the output shaft 2 as well. In the second illustrated example, the connecting/disengaging clutch 6 is configured in a synchronous mesh type, that is, the clutch teeth 7 provided on the outer periphery of one end of the output shaft 2 of the starting clutch C and the input shaft 3 of the multi-stage transmission Tm are connected to each other. A shift sleeve 8 is spline-fitted to the outer periphery of one end so as to be slidable in the axial direction, and is provided between the output and input shafts 2 and 3 to prevent engagement and disengagement between the shift sleeve 8 and the clutch teeth 7 on the outer periphery of the output shaft 2. It consists of a conventionally known synchronization device 9 for smoothing
The synchronizer 9 has a conical inner circumferential surface 11 that fits into a conical surface 10 formed on the outer circumference of the end of the output shaft 2, and is composed of a blocking ring 13 having a synchronizing gear 12 integrally formed on the outer circumference. Ru. Therefore, as shown in FIG. 2, when the shift sleeve 8 is disengaged from the clutch teeth 7 on the outer periphery of the output shaft 2, power is transmitted from the output shaft 2 to the input shaft 3 via the one-way clutch 5. However, since the disconnection clutch 6 is in the disconnected state, there is no connection between the input shaft 3 and the output shaft 2.
No power is transmitted to. Furthermore, if the shift fork 14 connected to the shift sleeve 8 is operated to slide the shift sleeve 8 in the axial direction with respect to the input shaft 3, to the left in FIG. Since the clutch teeth 7 on the outer periphery of the output shaft 2 are engaged with the clutch teeth 7 on the outer periphery of the output shaft 2 to connect the input shafts 2 and 3, power is also transmitted from the input shaft 3 to the output shaft 2. Therefore, when the disengagement clutch 6 is in the disengaged state as shown in FIG. However, the rotation of the input shaft 3 of the multi-stage transmission Tm is not transmitted to the engine output shaft. Therefore, when the vehicle is in a coasting state, the transmission of the reverse load from the drive wheels to the engine output shaft 1 is cut off by the one-way clutch 5, and the engine brake is not applied, making efficient coasting possible. The engine is not unnecessarily driven and rotated at high speed by the drive wheels, making it possible to drive economically while saving fuel. Next, when engine braking is required on a downhill road, etc., move the shift fork 14 to the left in FIG. 2 and engage the shift sleeve 8 with the clutch teeth 7 on the outer periphery of the output shaft 2 of the starting clutch C. That is, when the disconnection clutch 6 is brought into the connected state, the starting clutch C
Power transmission between the output shaft 2 of the multi-speed transmission Tm and the input shaft 3 of the multi-stage transmission Tm is performed from either direction, so that engine braking can be applied. In addition, the operation of the shift fork 14 is based on the multi-stage transmission.
This can be done by providing an auxiliary shift lever separately from the Tm shift lever, or by operating a disconnect/disconnect switch using a hydraulic servo, electromagnetic solenoid, or the like. FIG. 3 shows a second embodiment of the present invention, in which the power of the engine E is transmitted to its output shaft 1.
From fluid torque converter F, transmission control device
T'c, multi-stage auxiliary transmission Ta, reduction gear R,
It is transmitted to the drive wheels through the differential gear mechanism D and the wheel drive shaft A. The fluid torque converter F is connected to the engine output shaft 1
The turbine wheel 2 consists of a pump wheel 21 connected to the turbine wheel 21, a turbine wheel 23 connected to the turbine shaft 22, and a stator wheel 25 connected to the stator shaft 24.
3 are one-way clutches 26 arranged in parallel with each other.
and the auxiliary transmission via the disengagement clutch 27.
The input shaft 28 is selectively engaged and disengaged by low, medium and high speed hydraulic clutches C ₃ , C ₂ , C ₁ and first and second dog clutches D ₁ and D _2. It is connected to an output shaft 29 via transmission gear trains C″ ₁ to C″ ₃ and C″ ₄ for forward 1st to 3rd speeds and reverse 1st speed, and the output shaft 29 is connected to a differential gear mechanism via a reduction gear device R. D. Note that P is a parking gear equipped with a lock pawl for locking the output shaft 29 of the auxiliary transmission Ta.Next, the configuration of the transmission control device T'c will be explained with reference to FIG. Then, the turbine shaft 22 and the auxiliary transmission
A one-way clutch 26 that transmits driving force only from the turbine shaft 22 to the input shaft 28 in a fixed rotational direction and a disconnection clutch 27 that is controlled to connect and disconnect by hydraulic pressure are provided in parallel between the input shaft 28 of the Ta. ,
The connecting/disconnecting clutch is constructed of a hydraulic multi-plate type, that is, a clutch inner 30 is integrally formed at one end of the turbine shaft 22, and a hydraulic cylinder 32 is spline-coupled to the input shaft 28 of the auxiliary transmission Ta. A clutch outer 31 is provided, and a plurality of first friction plates 33 are provided on the clutch inner 30.
However, the clutch outer 31 also includes a plurality of second friction plates 34 which are alternately overlapped with the first friction plates 33.
A pressure piston 35 is housed in the hydraulic cylinder 32, and is slidably engaged with a spline to one side of the groups of friction plates 33, 34. Pressure receiving ring 3
6 is fixed to the clutch outer 31. The hydraulic cylinder 32 includes an oil passage 37 bored in the clutch outer 31, an annular oil passage 38 formed on the outer periphery of one end of the input shaft 28, and an oil passage 39 penetrating the inside of the input shaft 28.
It communicates with a hydraulic pump 44 connected to an oil tank 43 via an annular oil passage 40 on the outer periphery of the input shaft 28 and an oil passage 42 having a two-way switching valve 41 interposed therebetween. The oil passage 42 also communicates with an oil tank 43 between the two-way switching valve 41 and the hydraulic pump 44 via a relief valve 45. Therefore, when the two-way switching valve 41 is switched to the position shown in FIG.
Hydraulic cylinder 32 through 0, 39, 38, 37
The pressurizing piston 35 moves to the left in FIG. 4, cooperates with the pressure receiving ring 36, and frictionally connects the first and second friction plates 33, 34 groups, that is, puts the disconnecting clutch 27 into the operating state. The turbine shaft 22 and the input shaft 28 can be brought into a connected state. On the other hand, when the two-way switching valve 41 is switched to the lower side in FIG. ,
The first and second friction plate groups 33 and 34 are separated from each other, the disconnection clutch 27 becomes inoperative, and the turbine shaft 22 and the input shaft 28 are connected only through the one-way clutch 26. By the way, each of the clutches 27, C ₁ to C ₃ and D ₁ of the transmission control device T'c and the auxiliary transmission Ta,
By appropriately operating D ₂ , the gear characteristics as shown in Table 1, by way of example, can be obtained.

[Table] In Table 1, P, R, N, and D represent the parking, reverse, neutral, and automatic shift ranges, respectively, and 1, 2, and 3 represent the low, medium, and high speed ranges of manual shift, respectively. ing. Furthermore, −
and ON indicate the inoperative and activated states of each clutch. In Table 1, the reverse speed range R where the engagement/disengagement clutch 27 is in the operating state, and the low range of manual shifting,
An engine braking effect can be obtained at each shift position of medium, high-speed ranges 1, 2, and 3, but in a shift range where the disengagement clutch 27 is in a non-operating state, such as automatic shift range D, the engine brake does not work and the inertia is applied. Driving is automatically achieved and fuel economy driving is possible. Therefore, in an automatic transmission system as shown in Table 1, general driving is performed in the automatic transmission range, and when engine braking is required, engine braking effects are obtained in the manual transmission range, such as hold ranges 1, 2, and 3. The vehicle can then be shifted to the desired position and driven according to the driver's wishes. In this embodiment, the transmission control device T'c is arranged between the fluid torque converter F and the auxiliary transmission Ta, but instead, the transmission control device T'c is arranged between the engine output shaft 1 and the fluid torque converter F, or the auxiliary transmission It may be provided between Ta and the reduction gear device R. For operating the two-way switching valve 41, it is necessary to select an easy-to-operate method depending on the structure of the transmission of the vehicle to which the transmission control device T'c is applied. As an example,
When this device is applied to a manual transmission, a manual switching shift lever that interlocks with the two-way switching valve 41 is provided near the transmission shift lever, and the two-way switching valve 41 is switched by manual operation. You can do it like this. Alternatively, the two-way switching valve 41 may be provided with a switching control mechanism using a hydraulic servo or an electromagnetic coil, and this switching control mechanism may be operated by a manual switch. Further, when the present device is applied to a hydraulic automatic transmission, it is preferable to switch and control the two-way switching valve 41 in conjunction with a manual valve that controls the supply and discharge of oil to each transmission element. For example, in the automatic shift range D, the disengagement clutch 27 of the transmission control device T'c is always kept in the disengaged state, and in the 1st, 2nd, 3rd, and low speed ranges of the manual shift range, the disengagement clutch 27 is kept in the disengaged state. By configuring the hydraulic circuit so that it is in the connected state, economical driving can be achieved by coasting in which the engine brake is not applied in the automatic transmission range, and at the same time, in the manual transmission range (so-called hold position), the transmission position where the engine brake is applied is That's what you get. FIG. 5 shows an embodiment in which a 3-speed planetary gear type auxiliary transmission Ta is used instead of the auxiliary transmission Ta in the embodiment shown in FIG. It has been done. In this embodiment, the auxiliary transmission T′a includes a one-way clutch 26
an input shaft 51 connected to the turbine shaft 22 via a coupling/disconnection clutch 27; an intermediate shaft 52 coupled to the input shaft 51 via a first hydraulic clutch _C'1 ; The second intermediate cylinder shaft 53 is connected to the input shaft 51 via the second hydraulic clutch _C'2 , and the second intermediate cylinder shaft 53 is arranged so as to surround the outer circumference of one end of the second intermediate cylinder shaft 53. A first band brake B1 that can stop the rotation of the two-input cylinder shaft 53, and a first band brake _B1 that can stop the rotation of the two-input cylinder shaft 53;
It consists of a planetary gear transmission mechanism 55 that connects the intermediate cylinder shaft 53 to the output shaft 54, and the planetary gear transmission mechanism 55 is rotatably provided on the outer periphery of the second intermediate cylinder shaft 53,
A rotary support member 56 connected to a fixed part via a one-way clutch C' ₃ , and a second band brake disposed around the outer circumference of the rotary support member 56 and capable of stopping rotation of the rotary support member 56 during operation. B ₂ and the first and second speed change gear trains G ₁ and G ₂ provided between the planetary rotation shaft 57 supported by the rotation support member, the first intermediate shaft 52 and the second intermediate cylinder shaft 53; ,
A third shaft provided between the planetary rotating shaft 57 and the output shaft 54
It consists of a transmission gear train _G3 . Thus, the disengagement clutch 27 of the transmission control device T'c, the first and second hydraulic clutches C' ₁ and C' ₂ and the first and second band brakes B ₁ and B ₂ of the auxiliary transmission T'a. By appropriately operating the gear shift characteristics, for example, the gear characteristics shown in Table 2 can be obtained.

[Table] In this example, the forward ranges are two first and second automatic shift ranges D ₁ and D ₂ , and three manual shift ranges.
A total of five ranges are provided, including low speed, medium speed, and high speed ranges 1, 2, _and 3.
is in a non-operating state, allowing coasting without being affected by engine braking, while in the second automatic shift range D ₂ and manual shift range, that is, hold ranges 1, 2, and 3, the transmission control device T'c is disconnected and disconnected. Since the clutch 27 is activated, an engine braking effect is obtained. In this embodiment as well, the transmission control device T'c is connected between the fluid torque converter F and the engine output shaft 1, or between the auxiliary transmission device T'a and the reduction gear device R.
It may be provided between. Incidentally, in the first embodiment corresponding to FIG. 1 described above, the transmission control device T'c shown in FIG. 4 can be adopted instead of the transmission control device Tc shown in FIG. In the third and fourth embodiments corresponding to FIGS. 3 and 5, respectively, the transmission control device Tc of FIG. 2 may be employed in place of the transmission control device T'c of FIG. 4. As described above, according to the present invention, in a vehicle power transmission device that connects an output shaft of an engine and a wheel drive shaft via a multi-stage transmission, there is a gap between the output shaft of the engine and the input shaft of the multi-stage transmission. The power transmission path includes an input line from the output shaft to the engine output shaft in order to automatically cut off the transmission of reverse load from the input shaft of the multi-stage transmission to the engine output shaft when the vehicle enters a coasting state while running. A one-way clutch that transmits power only in the direction of the shaft is interposed, and the power transmission path is further provided with a one-way clutch that bypasses the one-way clutch and transmits the reverse load to the multi-stage gear shift even when the vehicle is in the coasting state. In order to transmit power from the input shaft of the device to the output shaft of the engine at any time, a disconnection clutch that can connect and disconnect power at will is arranged in parallel to the one-way clutch, so that the disconnection clutch is maintained in the disconnected state. If you do,
When the vehicle enters a coasting state while running, a one-way clutch can automatically cut off the transmission of reverse load from the wheel drive shaft to the engine output shaft, making the vehicle nimble without being affected by engine braking. During this period, the engine output shaft is not rotated at high speed due to the reverse load from the wheel drive shaft, so economical running is possible without wasting fuel. It is very convenient because it is done automatically. In addition, by simply switching the disengagement clutch to the engaged state, it becomes possible to transmit the reverse load from the wheel drive shaft to the engine output shaft, so that the normal engine braking effect can be easily obtained as required. Furthermore, since the one-way clutch and the disengagement clutch are arranged between the output shaft of the engine and the input shaft of the multi-speed transmission, both clutches can be placed outside the multi-speed transmission, making the layout easy. Furthermore, the location of the speedometer rotary shaft, which is generally interlocked and connected to the output shaft of the transmission, is not restricted by the two clutches.

[Brief explanation of drawings]

The figures show an embodiment of the vehicle power transmission device according to the present invention, and FIG. 1 is a schematic diagram of the first embodiment, FIG. 2 is an enlarged sectional view of the transmission control device,
FIG. 3 is a schematic diagram of a second embodiment of the invention, FIG. 4 is an enlarged sectional view of the transmission control device, and FIG. 5 is a schematic diagram of a third embodiment of the invention. 1... Engine output shaft, 3, 28, 51... Input shaft, 5, 26... One-way clutch, 6, 27...
...disconnection clutch, A...wheel drive shaft, E...engine, F...fluid torque converter, Ta, T'a
...Auxiliary transmission, Tm...Transmission.

Claims (1)

[Scope of Claims] 1. In a vehicle power transmission device that connects an output shaft of an engine and a wheel drive shaft via a multi-stage transmission, power transmission between the output shaft of the engine and an input shaft of the multi-stage transmission In order to automatically cut off the transmission of reverse load from the input shaft of the multi-stage transmission device to the engine output shaft when the vehicle enters a coasting state while running, there is a direction from the output shaft to the input shaft. A one-way clutch is interposed in the power transmission path that transmits power only to the input of the multi-speed transmission, and the power transmission path bypasses the one-way clutch and transmits the reverse load to the input of the multi-speed transmission even when the vehicle is in the coasting state. 1. A power transmission device for a vehicle, characterized in that a disconnection clutch capable of arbitrarily connecting and disconnecting power is disposed in parallel with the one-way clutch so that power can be transmitted from the shaft to the engine output shaft at any time. 2. The vehicle according to claim 1, wherein the one-way clutch and the disengagement clutch are disposed between a fluid torque converter connected to the engine output shaft and a multi-stage transmission connected to the wheel drive shaft. power transmission device. 3. The power transmission device for a vehicle according to claim 1 or 2, wherein the connecting/disconnecting clutch is a synchronizing clutch. 4. The power transmission device for a vehicle according to claim 1, 2 or 3, wherein the connecting/disconnecting clutch is constituted by a hydraulic multi-plate clutch. 5. The power transmission device for a vehicle according to claim 1 or 4, wherein the operating member for the engagement/disengagement clutch is provided separately from the shift lever of the transmission. 6. The power transmission device for a vehicle according to claim 5, wherein the operating member of the connecting/disengaging clutch is constituted by a shift lever. 7. The power transmission device for a vehicle according to claim 6, wherein the operation of the hydraulic multi-plate clutch is controlled in conjunction with a shift lever of the transmission.