JPH0459173B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an automatic transmission for an electric vehicle.

Electric vehicles equipped with electric motors that have relatively ideal torque characteristics also require a transmission in order to achieve both hill-climbing performance and maximum vehicle speed. Moreover, an automatic transmission is preferable, considering that the electric motor is low in noise, making it difficult to time the gear shift manually, and that it is frequently used in town.

Incidentally, since automatic transmissions shift gears regardless of the driver's will, it is important to minimize the shock of shifting. Normal automobiles that use an internal combustion engine as a drive source use a torque converter to alleviate shift shock due to slip. There is a problem in terms of efficiency when using a torque converter with losses.

The present invention has been made based on such consideration, and its object is to provide an efficient automatic transmission for an electric vehicle that controls the output of an electric motor during gear shifting to relieve gear shifting shock.

The automatic transmission for an electric vehicle according to the present invention includes an input shaft connected to a rotating shaft of an electric motor so as to be able to transmit power, an output shaft connected coaxially and relatively rotatably to the input shaft, and an output shaft connected to the input shaft so as to be able to rotate relative to each other. A planetary gear unit comprising a ring gear integrally provided, a sun gear rotatably provided on the input shaft, and a carrier rotatably supporting a planetary gear that is integrally provided on the input shaft and meshes with the ring gear and sun gear. a cone clutch that is spline-coupled to the sun gear so as to be movable in the axial direction and selectively engages with the fixing member or the ring gear to switch the planetary gear unit to a low gear side or a high gear side; a one-way clutch that receives a reaction force acting on the sun gear when the cone clutch is engaged with a fixed member and while the cone clutch is moved to engage the ring gear, and a solenoid; a control device that automatically controls the energization of the cone clutch according to the driving condition of the vehicle to control the operation of the cone clutch, a rotation speed sensor that detects the rotation speed of the cone clutch, and a rotation speed sensor that detects the rotation speed of the cone clutch; an F/V converter that converts an output to F/V and outputs the output; an F/V converter that operates by detecting the operation of the cone clutch that switches the planetary gear unit to a high gear side based on a signal applied to the solenoid; The electric motor controller is provided with an electric control device comprising a motor controller that becomes inactive after a predetermined period of time has passed after inputting an output from the electric motor, and cuts off or reduces the input given to the electric motor by a predetermined amount during operation.

As a result, in the present invention, when switching from the low gear side to the high gear side of the planetary gear unit, from the time when a signal is applied to the solenoid until a predetermined period of time has elapsed after the cone clutch starts engaging with the ring gear, Since the input applied to the electric motor can be cut off or reduced by a predetermined amount by the motor controller, and the output of the electric motor can be stopped or reduced, the cone clutch and the ring gear can be smoothly engaged. . Since this operation is instantaneous and can be optimally achieved by appropriately setting the above-mentioned time, the shift shock can be efficiently alleviated.

An embodiment of the present invention will be described below based on the drawings. FIG. 1 shows a power transmission device for an electric vehicle that includes an automatic transmission according to the present invention, and in this power transmission device, the transmission according to the present invention is provided in parallel with an electric motor 10. The electric motor 10 is a motor that can follow the input Io with high precision, includes a rotating shaft 12 having a gear 12a at the tip, and is assembled into a casing 14.
The input shaft 16 of the transmission is the electric motor 1
0, and is rotatably assembled to the casing 14. This input shaft 16 consists of a large diameter shaft 16A and a small diameter shaft 16B spline connected to the large diameter shaft 16A, and is connected to the gear 12a of the electric motor 10 via an input gear train A consisting of an input gear 18 and an idler gear 20 at the large diameter shaft 16A. has been done. Note that a known torsional damper mechanism B is interposed between the input shaft 16 and the input gear 18. Further, an oil pump 22 driven by the large diameter shaft 16A is attached to the outer periphery of the large diameter shaft 16A in the input shaft 16. Further, an output shaft 24 is connected coaxially and relatively rotatably to the right end of the input shaft 16. Output shaft 24 is flange 2
4a, and is rotatably assembled to the casing 14.

The planetary gear unit C is provided at the connection between the input shaft 16 and the output shaft 24, and includes a sun gear 26 rotatably assembled onto the input shaft 16 and a carrier 28 spline-coupled onto the input shaft 16.
and the flange 24a of the output shaft 24.
A ring gear 30 fixed to the top, a first planetary gear 32 rotatably supported by the carrier 28 and meshing with the ring gear 30, and a first planetary gear 32 (not shown) rotatably supported by the carrier 28 and meshing with the sun gear 26 and the first planetary gear 32. It is composed of two planetary gears. The operation of the planetary gear unit C is controlled (low gear side: deceleration, high gear side: same speed) by a cone clutch 34 and a one-way clutch 36 assembled on the cylindrical portion 26a of the sun gear 26.

The cone clutch 34 is connected to the cylindrical portion 2 of the sun gear 26.
6a is spline-coupled to be movable in the axial direction on the right side and is moved in the axial direction by a piston 40 connected via a ball bearing 38 and a spring 42 that urges the piston 40 to the left in the figure. is configured to be piston 40
is configured to move to the right against the spring 42 when a predetermined oil pressure is applied in the oil chamber R. Therefore, when no oil pressure is applied in the oil chamber R, the cone clutch 34 is pressed into engagement with the outer race 44 fixed in the casing 14 by the action of the spring 42, and holds the planetary gear unit C on the low gear side. , when a predetermined oil pressure is applied in the oil chamber R, it is moved to the right and press-fits into engagement with the ring gear 30, thereby switching the planetary gear unit C to the high gear side. Further, the supply and discharge of pressure oil into the oil chamber R is automatically performed according to the operating state of the vehicle by a hydraulic control device 50 shown in FIGS. 1 and 2. Note that the one-way clutch 36 is configured to receive a reaction force acting on the sun gear 30.

As shown in detail in FIG. 2, the hydraulic control device 50 includes a manual valve 51, a regulator valve 52, an accelerator valve 53, a pilot valve 54, and a first solenoid valve 55, as well as an accumulator 56 and a shift valve 57.
and a second solenoid valve 58.

The manual valve 51 has a spool 51a that is held at the position shown in the figure when the vehicle is moving forward, and is pushed a predetermined amount to the left in the figure and held at that position when the vehicle is moving backward. Even if the rotational direction of the oil pump 22 changes during forward or backward movement, the oil is controlled so that it always flows toward the regulator valve 52 side. Regulator valve 5
2 is the oil pressure from the pilot valve 54 applied to the oil chamber 52a through the orifice O1;
2b through the orifice O2 from the oil pump 22, and the spring 52c.
The operation is controlled by the oil chamber 52d.
The spool 52f has a spool 52f whose operation is controlled by a spool 52e that is moved upward by the oil pressure from the accelerator valve 53 applied to the pilot valve. 54, Accumulator 5
6 and shift valve 57, respectively.
Note that a part of the line pressure is applied to the lubricated portion 59 of the power transmission device through the orifice O3, and is supplied to the lubricated portion 59 as lubricating oil.

The accelerator valve 53 has a spool 53c that engages via a spring 53b with a plunger 53a that is pushed according to the amount of depression of the accelerator pedal, and is applied from the pilot valve 54 according to the amount of depression of the accelerator pedal. The hydraulic pressure is controlled and applied to the oil chamber 52d of the regulator valve 52. The oil pressure applied to the oil chamber 52d of the regulator valve 52 acts to increase the line pressure. The pilot valve 54 has a spool 54c which is controlled by the oil pressure from the oil pump 22 which is applied to the oil chamber 54a through the orifice O4 and which is controlled by the first solenoid valve 55 and a spring 54b. is open and the oil pressure in the oil chamber 53a is low, the supply of line pressure to the accelerator valve 53 is cut off as shown in the figure, and the accelerator valve 53 is closed.
is communicated with the drain port 54d, and line pressure is applied to the oil chamber 52a of the regulator valve 52 through the orifice O1, and when the first solenoid valve 55 is closed and the oil pressure in the oil chamber 54a is high, the line pressure is The supply to the oil chamber 52a is cut off, and the oil chamber 52a is communicated with the drain port 54d, and the line pressure is transferred to the accelerator valve 5.
Granted to 3. Note that an orifice O5 is interposed between the oil chamber 54a and the first solenoid valve 55.

The first solenoid valve 55 is a normally closed solenoid valve, which is energized to open when the electric motor 10 is started, and is de-energized when the vehicle speed exceeds a predetermined value shown by the dashed line in FIG. is configured to close. With such a configuration,
In this embodiment, when the vehicle speed is equal to or less than a predetermined value shown by the dashed line in FIG. As a result, the spool 52f is greatly pushed against the spring 52c, the amount of return to the oil pump 22 increases, the line pressure decreases, and the vehicle speed reaches the predetermined value shown by the dashed line in FIG. In this case, the oil pressure in the oil chamber 52a disappears and the spring 5 of the spool 52f
2c decreases, and the oil pump 22
The amount of reflux to the line decreases and the line pressure increases. Therefore, the load on the oil pump 22 can be significantly reduced when the vehicle speed is below the predetermined value shown by the dashed line in FIG. The driving distance per charge can be increased.

The shift valve 57 is provided in the oil chamber 57a through the orifice O6 and is connected to the second solenoid valve 58.
line pressure and spring 57 controlled by
When the second solenoid valve 58 is open and the oil pressure in the oil chamber 57a is low, the supply of line pressure to the oil chamber R is cut off and checked as shown in the figure. Drain port 57 from oil chamber R through valve V1
d, and when the second solenoid valve 58 is closed and the oil pressure in the oil chamber 57a is high,
The communication between the oil chamber R and the drain port 57d is cut off, and the oil chamber R is opened through the check valve V2 and the orifice O7.
Apply line pressure to the inside. When line pressure is applied in the oil chamber R, the piston 40 moves to the right against the spring 42 to press the cone clutch 34 into engagement with the ring gear 30, as shown in FIG. Switch to high gear. At this time, the piston 56a and spring 56b of the accumulator 56 work together to control the rising characteristics of the oil pressure supplied to the oil chamber R, thereby smoothly engaging the cone clutch 34 with the ring gear 30. Furthermore, when the oil chamber R communicates with the drain port 57d of the shift valve 57, oil is discharged into the oil chamber R and the accumulator 56.
The piston 40 returns under the biasing force of the spring 42 to press the cone clutch 34 into engagement with the outer race 44, thereby switching the planetary gear unit C from the high gear side to the low gear side.

The second solenoid valve 58 is a normally closed solenoid valve, which is energized to open when the electric motor 10 is started, and is set at a preset shift-up timing based on the vehicle speed and the amount of depression of the accelerator pedal (solid line in FIG. 3). When the shift-down timing (as shown by the broken line in Fig. 3) is reached, the power supply is stopped and closed, and in this state, the downshift timing is set in advance according to the vehicle speed and the amount of depression of the accelerator pedal. It is configured so that it is energized again and opens when it cools down.

Therefore, in this embodiment, as shown in FIG. 1, a rotation speed sensor 61 is disposed around the outer periphery of the cone clutch 34. Rotation speed sensor 61
Detects the number of rotations of the cone clutch 34, and inputs an output corresponding to the number of rotations to the F/V converter 62. The F/V converter 62 converts the output from the rotation speed sensor 61 into F/V and outputs the result, and the output is input to the motor controller 63.
The motor controller 63 is interposed in the energizing circuit of the electric motor 10, and is connected to the planetary gear unit C.
The operation of the cone clutch 34, which switches the F gear to the high gear side, is detected by an electric signal applied to the second solenoid valve 58 (specifically, when the second solenoid valve 58 is de-energized), and the cone clutch 34 is operated. It becomes inactive after a predetermined period of time has passed after inputting the output from the /V converter 62, and cuts off the input Io (according to the amount of depression of the accelerator pedal) applied to the electric motor 10 during operation or by a predetermined amount. decrease.

In this embodiment configured as described above, when the accelerator pedal is depressed when the vehicle is stopped, a corresponding input Io is applied to the electric motor 10, which outputs an output, and the output (driving force) is transferred to the gear. 12a
The signal is then transmitted to the input shaft 16 via the idle gear 20, input gear 18, and torsional damper mechanism B, and then to the carrier 28 of the planetary gear unit C. Therefore, while the vehicle speed and the amount of depression of the accelerator pedal are within the region to the left of the solid line in FIG. 3, the second solenoid valve 58 is open and the shift valve 57 cuts off the line pressure supply to the oil chamber R. ing. For this reason, the cone clutch 34
continues to be fixed to the outer race 44, the planetary gear unit C is held on the low gear side, and the rotation of the input shaft 16 is decelerated and transmitted to the output shaft 24. Thus, in a vehicle running in low gear, when the vehicle speed and the amount of accelerator pedal depression reach the solid line in FIG.
Solenoid valve 58 closes and shift valve 57
Line pressure is supplied to the oil chamber R at . Therefore, the cone clutch 34 moves to the right and the ring gear 3
0, the planetary gear unit C is automatically switched to the high gear side, and the input shaft 16 rotates at the same speed as the output shaft 2.
It is transmitted to 4. The one-way clutch 36 receives the reaction force of the sun gear 26 until the cone clutch 34 engages with the ring gear 30, but becomes free at the same time as the cone clutch 34 engages with the ring gear 30. Furthermore, in a vehicle running in high gear as described above, when the vehicle speed and the amount of depression of the accelerator pedal reach the broken line in FIG. 3,
The second solenoid valve 58 opens and the shift valve 5
At 7, the oil in the oil chamber R is discharged. Therefore, the cone clutch 34 moves to the left and engages the outer race 44, the planetary gear unit C is automatically switched to the low gear side, and the rotation of the input shaft 16 is decelerated and transmitted to the output shaft 24.

By the way, in this embodiment, when the planetary gear unit C is switched from the low gear side to the high gear side, a predetermined period of time elapses after the cone clutch 34 starts engaging the ring gear 30 after the signal is applied to the second solenoid valve 58. Until then, the electric motor 10 is controlled by the motor controller 63.
Since the input Io applied to the motor can be cut off or reduced by a predetermined amount, and the output of the electric motor 10 can be stopped or reduced, the cone clutch 34 and the ring gear 30 can be smoothly engaged.
Since this operation is instantaneous and can be optimally achieved by appropriately setting the above-mentioned time, the shift shock can be efficiently alleviated.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of a power transmission device for an electric vehicle equipped with a transmission according to the present invention, Fig. 2 is a schematic configuration diagram of a hydraulic control device in the transmission, and Fig. 3 is a schematic diagram of the hydraulic control device in the same transmission. It is a graph which shows the actuation timing of both solenoid valves in . Explanation of symbols, 10...Electric motor, 12...Rotating shaft, 16...Input shaft, 24...Output shaft, 26...Sun gear, 28...
...Carrier, 30...Ring gear, 32...Planetary gear, C...Planetary gear unit, 3
4... Cone clutch, 36... One-way clutch, 44... Outer race, 50... Hydraulic control device, 51... Manual valve, 52... Regulator valve, 53... Accelerator valve, 54
... Pilot valve, 55 ... First solenoid valve, 56 ... Accumulator, 57 ... Shift valve, 58 ... Second solenoid valve, 61
...Rotation speed sensor, 62...F/V converter, 63
...Motor controller.

Claims (1)

[Claims] 1. An input shaft connected to the rotating shaft of the electric motor so as to be capable of transmitting power, an output shaft connected coaxially and relatively rotatably to the input shaft, a ring gear integrally provided with the output shaft, and the input shaft. A planetary gear unit consisting of a sun gear rotatably provided on a shaft and a carrier that rotatably supports a planetary gear that is integrally provided on the input shaft and meshes with the ring gear and sun gear, and is movable in the axial direction on the sun gear. a cone clutch that is spline-coupled to and selectively engages with a fixed member or the ring gear to switch the planetary gear unit to a low gear side or a high gear side; and a cone clutch that is assembled to the sun gear so that the cone clutch engages with the fixed member. a one-way clutch that receives a reaction force acting on the sun gear while the cone clutch is moving to engage the ring gear; and a solenoid, the solenoid being energized depending on the driving state of the vehicle. and a control device that automatically controls the operation of the cone clutch, a rotation speed sensor that detects the rotation speed of the cone clutch, and an output from the rotation speed sensor that converts the output from the rotation speed sensor into F/V and outputs it. The F/V converter operates by detecting the operation of the cone clutch that switches the planetary gear unit to the high gear side based on a signal applied to the solenoid, and a predetermined period of time elapses after the output from the F/V converter is input. An automatic transmission for an electric vehicle, comprising an electric control device comprising a motor controller that later becomes inactive and cuts off or reduces input to the electric motor by a predetermined amount during operation.