JPH0459171B2 - - 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 considerations, and an object thereof is to provide an efficient automatic transmission base 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 is subjected to a reaction force acting on the sun gear when the cone clutch is engaged with a fixed member and while the cone clutch is moving to engage the ring gear; A first rotation speed sensor detects the rotation speed of the cone clutch; a second rotation speed sensor detects the rotation speed of the output shaft; A comparator that performs F/V conversion on the outputs from both rotational speed sensors and then compares them and outputs an output when the difference in output is less than a set value; a comparator that operates based on the output from the first rotational speed sensor and outputs an output from the comparator; The electric motor controller is provided with an electric control device comprising a motor controller that becomes inactive and cuts off or reduces input to the electric motor by a predetermined amount during operation.

As a result, in the present invention, when the planetary gear unit is switched from the low gear side to the high gear side, the motor controller provides an input to the electric motor from the time when the cone clutch starts to engage the ring gear until the cone clutch ends to engage the ring gear. Since the output of the electric motor can be stopped or reduced by a predetermined amount, the cone clutch and the ring gear can be smoothly engaged. Since this operation is instantaneous, it is possible to efficiently relieve the shift shock.

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 condition of the vehicle by a hydraulic control device shown in FIG. In addition, one-way clutch 36
is configured to receive a reaction force acting on the sun gear 30.

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

The manual valve 50 has a spool 50a 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 direction of rotation of the oil pump 22 changes when moving forward or backward, oil is always supplied to the regulator valve 51.
Control the flow to the side. Regulator valve 5
1 is the oil pressure from the pilot valve 53 applied to the oil chamber 51a through the orifice O1;
Hydraulic pressure from the oil pump 22 applied to 1b through orifice O2, and spring 51c
The operation is controlled by the oil chamber 51d.
It has a spool 51f whose operation is controlled by a spool 51e that is moved upward by the oil pressure from the accelerator valve 52 applied to the pilot valve. 53, Accumulator 5
5 and shift valve 56, respectively.
Note that a part of the line pressure is applied to the lubricated portion 58 of the power transmission device through the orifice O3, and is supplied to the lubricated portion 58 as lubricating oil.

The accelerator valve 52 has a spool 52c that engages via a spring 52b with a plunger 52a that is pushed according to the amount of depression of the accelerator pedal, and is applied from a pilot valve 53 according to the amount of depression of the accelerator pedal. The hydraulic pressure is controlled and applied to the oil chamber 51d of the regulator valve 51. The oil pressure applied to the oil chamber 51d of the regulator valve 51 acts to increase the line pressure. The pilot valve 53 has a spool 53c which is controlled by the oil pressure from the oil pump 22 which is applied to the oil chamber 53a through the orifice O4 and which is controlled by the first solenoid valve 54 and a spring 53b. is open and the oil pressure in the oil chamber 53a is low, the supply of line pressure to the accelerator valve 52 is cut off as shown in the figure, and the accelerator valve 52 is closed.
is communicated with the drain port 53d, line pressure is applied to the oil chamber 51a of the regulator valve 51 through the orifice O1, and when the first solenoid valve 54 is closed and the oil pressure in the oil chamber 53a is high, the line pressure is The supply to the oil chamber 51a is cut off, and the oil chamber 51a is communicated with the drain port 53d, and the line pressure is transferred to the accelerator valve 5.
Granted to 2. Note that an orifice O5 is interposed between the oil chamber 53a and the first solenoid valve 54.

The first solenoid valve 54 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 51f is greatly pushed against the spring 51c, 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 51a disappears and the spring 5 of the spool 51f
The amount of sliding resistance against 1c 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 56 is provided in the oil chamber 56a through the orifice O6 and is connected to the second solenoid valve 57.
line pressure and spring 56 controlled by
When the second solenoid valve 57 is open and the oil pressure in the oil chamber 56a is low, the line pressure is cut off from being supplied to the oil chamber R as shown in the figure, and a check is performed. Drain port 56 from oil chamber R through valve V1
d, and when the second solenoid valve 57 is closed and the oil pressure in the oil chamber 56a is high,
The communication between the oil chamber R and the drain port 56d 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 55a and spring 55b of the accumulator 55 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 56d of the shift valve 56, the oil in the oil chamber R and the accumulator 55 is discharged.
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 57 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.
is located. The first rotational speed sensor 60 detects the rotational speed of the cone clutch 34, and inputs an output corresponding to the rotational speed to a comparator 62 and a motor controller 63. Second rotation speed sensor 6
1 detects the rotational speed of the output shaft 24, and outputs an output corresponding to the same rotational speed to a comparator 62.
is input. The comparator 62 has an F/V conversion function, converts the outputs from both rotational speed sensors 60 and 61 into F/V, compares them, and outputs an output when the output difference is less than a set value (almost zero). The output is input to the motor controller 63. Motor controller 6
3 is interposed in the energizing circuit of the electric motor 10, and is activated by the output from the first rotation speed sensor 60 and deactivated by the output from the comparator 62. Input Io given (according to the amount of accelerator pedal depression)
cut off or reduce by a predetermined amount.

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) 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 57 is open and the shift valve 56 cuts off the line pressure supply to the oil chamber R. ing. Therefore, 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, when the vehicle speed and the amount of depression of the accelerator pedal reach the solid line in FIG. 3 in a vehicle running in a low gear, the second solenoid valve 57 closes and line pressure is supplied to the oil chamber R at the shift valve 56. be done. 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 57 opens and the shift valve 5
At 6, 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, the motor controller 63 controls the electric motor 10 from when the cone clutch 34 starts to engage the ring gear 30 to when it ends. 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, it is possible to efficiently relieve the shift shock.

[Brief explanation of drawings]

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, 34
... Cone clutch, 36 ... One-way clutch, 44 ... Outer race, 50 ... Manual valve, 51 ... Regulator valve, 52 ...
Accelerator valve, 53...Pilot valve, 5
4...First solenoid valve, 55...Accumulator, 56...Shift valve, 57...Second solenoid valve, 60...First rotation speed sensor, 6
1...Second rotation speed sensor, 62...Comparator, 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 automatically operates the cone clutch according to the driving condition of the vehicle. A first rotation speed sensor detects the rotation speed of the cone clutch, a second rotation speed sensor detects the rotation speed of the output shaft, and outputs from both of these rotation speed sensors are A comparator that compares after V conversion and outputs an output when the output difference is less than a set value, operates based on the output from the first rotation speed sensor, becomes inactive due to the output from the comparator, and outputs an output when the output difference is less than a set value. An automatic transmission for an electric vehicle comprising an electric control device comprising a motor controller that cuts off or reduces input to a motor by a predetermined amount.