JPH08223709A - Automatic transmission for motor-driven vehicle - Google Patents

Abstract

PURPOSE: To enhance the energy efficiency by a simple structure by outputting a gear ratio switching signal and a motor drive signal based on detected number of revolutions, vehicle speed and running state. CONSTITUTION: At the time of running, a shift position is read from a shift sensor 22. If the shift position is D, whether a transmission 14 is at a first speed or not is judged. If the transmission 14 is at the first speed, whether a shift-up is conducted or not is judged from the vehicle speed detected by a vehicle speed sensor 18 and the opening detected by an accelerator sensor 24. In the case of the shift-up, the torque of a motor 12 is set to '0', and the transmission 14 is set to a second speed by gear ratio switching means 28 after a synchronous operation. In the case of a shift-down, similar operation is conducted to realize the automatic gear shifting of high energy efficiency with a simple structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for automatically shifting electric vehicles such as electric vehicles and electric bicycles.

[0002]

2. Description of the Related Art As a conventional transmission for an electric vehicle, the one described in Japanese Patent Application Laid-Open No. 60-91804 is known although it is manual. However, since this uses an electromagnetic clutch, it has a problem that a special transmission is required, the number of parts is large, and the power consumption is large. Therefore, it is difficult to construct an automatic transmission based on such a transmission because many problems are involved.

Further, in an automatic transmission of a gasoline vehicle,
A torque converter is used. However, when the torque converter is used, there is a problem that the energy efficiency becomes poor. In particular, an electric vehicle that travels while mounting a heavy battery is required to have higher energy efficiency than a gasoline vehicle. Therefore, it is practically difficult to configure the automatic transmission of the electric vehicle using the torque converter.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an automatic transmission for an electric vehicle which has a simple structure and high energy efficiency.

[0005]

SUMMARY OF THE INVENTION An automatic transmission for an electric vehicle according to the present invention includes a transmission for transmitting power generated by a traveling motor to a drive shaft at a predetermined gear ratio, and a rotational speed of the traveling motor. A rotation speed sensor for detecting, a vehicle speed sensor for detecting a vehicle speed, a shift sensor for detecting a traveling state set by a shift lever, an accelerator sensor for detecting an accelerator opening, and a rotation speed detected by the rotation speed sensor. A controller that outputs a gear ratio switching signal and a driving motor drive signal based on the number, the vehicle speed detected by the vehicle speed sensor, the traveling state detected by the shift sensor, the opening degree detected by the accelerator sensor, and the like. A gear ratio switching means for switching the gear ratio of the transmission in response to a gear ratio switching signal output from the controller; It is obtained by a drive circuit for supplying power from the battery to the traction motor according to the running motor drive signals output from la.

[0006]

The speed sensor detects the speed of the traveling motor, the vehicle speed sensor detects the vehicle speed, the shift sensor detects the traveling state set by the shift lever, and the accelerator sensor detects the opening degree of the accelerator. . The controller outputs a gear ratio switching signal and a traveling motor drive signal based on the detected rotation speed, vehicle speed, traveling state, opening degree, and the like. The gear ratio switching means switches the gear ratio of the transmission according to the gear ratio switching signal. The drive circuit supplies battery power to the traveling motor in response to the traveling motor drive signal. The transmission transmits the power generated by the traveling motor to the drive shaft at a predetermined gear ratio.

[0007]

1 and 2 show a first embodiment of an automatic transmission according to the present invention, FIG. 1 is a block diagram showing the overall construction, and FIG. 2 is a portion showing a gear ratio switching means in FIG. FIG. Hereinafter, description will be given with reference to these drawings.

The automatic transmission 10 includes a transmission 14 for transmitting the power generated by the traveling motor 12 to the drive shaft 13 at a predetermined gear ratio, and the rotational speed n of the traveling motor 12.
The rotation speed sensor 16 that detects the vehicle speed, the vehicle speed sensor 18 that detects the vehicle speed V, the shift sensor 22 that detects the traveling state S set by the shift lever 20, and the opening degree A of the accelerator (not shown). The accelerator sensor 24, the rotational speed n detected by the rotational speed sensor 16, the vehicle speed V detected by the vehicle speed sensor 18, the traveling state S detected by the shift sensor 22, the opening degree A detected by the accelerator sensor 24, etc. A controller 26 that outputs a gear ratio switching signal G and a traveling motor drive signal d based on the above, a gear ratio switching unit 28 that switches the gear ratio of the transmission 14 according to the gear ratio switching signal G output from the controller 26, and a controller 26. And a drive circuit 32 that supplies the electric power of the battery 30 to the traveling motor 12 according to the traveling motor drive signal d output from Those were example.

The transmission 14 is of a general mesh type, and has an input shaft 141 directly connected to the rotating shaft of the traveling motor 12, a sleeve and hub 142 inserted through the input shaft 141,
Input shaft first speed gear 143, input shaft second speed gear 144, output shaft 145 directly connected to drive shaft 13, and output shaft 145
The output shaft first speed gear 146 and the output shaft second speed gear 147 inserted through

The sleeve and hub 142 is inserted between the input shaft first speed gear 143 and the input shaft second speed gear 144, and the input shaft 1
It is designed to move in the axial direction of 41. Meanwhile, the sleeve and hub 142 and the input shaft first speed gear 14
A meshing mechanism 148 is formed on the third gear or the input shaft second speed gear 144. Therefore, the sleeve and hub 142 moves in the axial direction of the input shaft 141, so that the input shaft first speed gear 1
It is possible to select three ways: meshing with 43 (first speed), meshing with the input shaft second speed gear 144 (second speed), and neither meshing (neutral). Further, since the sleeve and hub 142 is fixed in the radial direction of the input shaft 141, it always rotates together with the input shaft 141.

The input shaft first speed gear 143 and the input shaft second speed gear 144 are rotatably provided to the input shaft 141 via a bearing (not shown), while the output shaft first speed gear 14 is rotatably provided.
6 and the output shaft second speed gear 147 are always meshed.

Since the output shaft first speed gear 146 and the output shaft second speed gear 147 are fixedly mounted on the output shaft 145, they always rotate together with the output shaft 145.

The gear ratio switching means 28 comprises a screw feed mechanism 281 for moving the sleeve and hub 142 in the axial direction of the input shaft 141, and a stepping motor 282 as a drive source thereof. Further, the screw feeding mechanism 281 is provided with a stepping motor 282.
Ball screw (male screw) 283 directly connected to the rotating shaft of
And a gear shift arm (female screw) 284 engaged with the sleeve and hub 142.

The traveling motor 12 is a DC brushless motor. The rotation speed sensor 16 is a rotary encoder provided in the traveling motor 12. Vehicle speed sensor 18
Is a tacho generator that detects the vehicle speed V from the rotation speed of the output shaft 145 (drive shaft 13). The shift sensor 22 is a micro switch provided at each of the drive D, neutral N, and reverse R positions with which the shift lever 20 contacts. The accelerator sensor 24 is a potentiometer that outputs a DC voltage (opening A) according to the amount of depression of an accelerator pedal (not shown). The controller 26 is a microcomputer including an A / D converter and the like. The drive circuit 32 is a general one composed of a gate pulse generator for PWM control, a transistor for driving a motor, and the like.

FIG. 3 shows an automatic transmission 10 at the time of starting.
6 is a flowchart showing an example of the operation of FIG. Below, Figure 1
It will be described with reference to FIG. The operation of the automatic transmission 10 shown in FIGS. 3, 4, 6 and 7 is mainly performed by the controller 26 and its computer program.

First, when the electric vehicle is started, the running state (hereinafter referred to as "shift position") is read from the shift sensor 22 (step 101). The shift position is either N, D or R. Then, it is determined whether the shift position is N (step 102). If the shift position is N, the gear ratio switching means 28 makes the transmission 14 neutral (step 103), and the process returns to step 101. Here, whether or not the transmission 14 is in neutral can be known by providing, for example, a micro switch or the like for detecting the position of the gear shift arm 284. That is, if the transmission 14 is in neutral, nothing is done,
Stepping motor 282 if first or second speed
Gearshift arm 28 to neutral position by
Move 4 The neutral position is a position where the sleeve and hub 142 does not mesh with either the input shaft first speed gear 143 or the input shaft second speed gear 144.

If the shift position is not N in step 102, it is determined whether the shift position is D (step 104). If the shift position is D, first, the traveling motor 12 is slightly rotated in the forward direction in order to easily enter the gear (step 105). Subsequently, the transmission 14 is set to the first speed by the gear ratio switching means 28 (step 106). That is, the stepping motor 282 moves the gear shift arm 28 to the first speed position.
Move 4 First-speed position means sleeve and hub 14
2 is a position where it meshes with the input shaft first speed gear 143. At this time, the input shaft first speed gear 143
By engaging the sleeve and hub 142,
It rotates together with the input shaft 142 and the rotating shaft of the traveling motor 12. Therefore, the output shaft first speed gear 146, which is always meshed with the input shaft first speed gear 143, also rotates, which causes the output shaft 145 and the drive shaft 13 to rotate. The input shaft second speed gear 144 is rotated by the output shaft second speed gear 147, but idles with respect to the input shaft 141. Subsequently, in this state, the traveling motor 12 is rotated in the forward direction to perform creep traveling (step 107).

In step 104, the shift position is D
If not, it is determined whether the shift position is R (step 108). If the shift position is R,
First, the traveling motor 12 is slightly rotated in the reverse direction in order to make it easy to enter the gear (step 109). Subsequently, the transmission 14 is set to the first speed by the gear ratio switching means 28 (step 110). Subsequently, in this state, the traveling motor 12 is rotated in the reverse direction to perform creep traveling (step 111).

At step 108, the shift position is set to R.
If not, the process returns to step 101. Also, step 1
If 07 or 111 is executed, the starting operation is completed.

FIG. 4 shows an automatic transmission 10 during traveling.
6 is a flowchart showing an example of the operation of FIG. FIG. 5 is a shift diagram for determining whether to shift gears based on the vehicle speed and the accelerator opening. Hereinafter, description will be given with reference to FIGS. 1 to 5.

First, when the electric vehicle is running (here, when moving forward), the shift position is read from the shift sensor 22 (step 121). Then, it is determined whether the shift position is N (step 122). If the shift position is N, the torque of the traveling motor 12 is set to "0" (step 123), and the gear ratio switching means 28 is set.
Thus, the transmission 14 is made neutral (step 124), and the process returns to step 121.

If the shift position is not N in step 122, it is determined whether the shift position is D (step 125). If the shift position is D, it is determined whether or not the transmission 14 is in the first speed (step 126). If the transmission 14 is in the first speed, the vehicle speed V detected by the vehicle speed sensor 18 and the accelerator sensor 2
Reading the opening A detected in step 4 (step 127),
By these values and the straight line a shown in the shift diagram of FIG. 5,
It is determined whether to shift up (changing from first gear to second gear) (step 128). Vehicle speed V in FIG.
If the intersection of the opening A and the right side of the straight line a, upshift is executed. That is, the torque of the traveling motor 12 is set to "0" (step 129), and the gear ratio switching means 28 is set.
Then, the transmission 14 is made neutral (step 130), and after a synchronizing operation A (step 131) which will be described later, the transmission 14 is set to the second speed by the gear ratio switching means 28 (step 132), and the process ends.

In step 126, the transmission 1
If 4 is not the first speed, the vehicle speed V detected by the vehicle speed sensor 18 and the opening A detected by the accelerator sensor 24 are read (step 137), and these values and the straight line b shown in the shift diagram of FIG. It is determined whether to shift down (changing from the second speed to the first speed) by the step S13.
8). In FIG. 5, if the intersection of the vehicle speed V and the opening A is on the left side of the straight line b, the downshift is executed. That is, the torque of the traveling motor 12 is set to "0" (step 13
9), the transmission 14 is made neutral by the gear ratio switching means 28 (step 140), and after the synchronizing operation B (step 141) described later, the transmission 14 is set to the first speed by the gear ratio switching means 28 (step 142), and the operation is completed. To do.

When the shift position is not D in step 125, the shift up is not performed in step 128 or the shift down is not performed in step 138, the process returns to step 121, respectively.

FIG. 6 is a flowchart showing the synchronizing operation A in FIG. FIG. 7 is a flowchart showing the synchronizing operation B in FIG. 6 and 7, the rotation speed n ₁ is the rotation speed of the traveling motor 12 (the input shaft 141 and the sleeve and hub 142).
The rotation speed n ₂ means the rotation speed of the input shaft second speed gear 144, and the rotation speed n ₃ means the rotation speed of the input shaft first speed gear 143. Hereinafter, description will be given with reference to FIGS. 1 to 7.

The synchronizing operation A shown in FIG. 6 is for shifting from the first speed to the second speed. In this case, the traveling motor 1
It is necessary to reduce the rotation speed n _{1 of} 2. That is, a negative torque is generated in the traveling motor 12 via the drive circuit 32 to reduce the rotation speed n ₁ (step 15).
1). Subsequently, the rotation speed n ₁ is detected (step 15
2), the rotation speed n _{2 of the} input shaft second speed gear 144
Is detected (step 153). The rotation speed n ₁ can be detected by the rotation speed sensor 16. The rotation speed n ₂ is the same as the input shaft second speed gear 144 when the input shaft 141
Since it is idling, it is determined by the rotation speed of the output shaft 145 detected by the vehicle speed sensor 18 and the gear ratio of the input shaft second speed gear 144 and the output shaft second speed gear 147. And n ₁ = n
Determine ₂ or not (step 154), and terminates if n ₁ = n _2, returns to n ₁ = n ₂ unless step 151. In this way, the rotation speeds of the sleeve and hub 142 and the input shaft second speed gear 144 are equalized,
Smooth these meshes.

The synchronizing operation B shown in FIG. 7 is for shifting from the second speed to the first speed. In this case, the traveling motor 1
It is necessary to increase the rotation speed n _{1 of} 2. That is, a positive torque is generated in the traveling motor 12 via the drive circuit 32 to increase the rotation speed n ₁ (step 16
1). Subsequently, the rotation speed n ₁ is detected (step 16
2), the rotation speed n _{3 of the} input shaft first speed gear 143
Is detected (step 163). The rotation speed n ₁ can be detected by the rotation speed sensor 16. The rotational speed n ₃ is the same as the input shaft first speed gear 143 when the input shaft 141
Since it is idling, it is determined by the rotation speed of the output shaft 145 detected by the vehicle speed sensor 18 and the gear ratio of the input shaft first speed gear 143 and the output shaft first speed gear 146. And n ₁ = n
₃ whether the determined (step 164), and terminates if n ₁ = n _3, back to n ₁ = n ₃ unless step 161. In this way, the rotation speeds of the sleeve and hub 142 and the input shaft first speed gear 141 are equalized,
Smooth these meshes.

FIG. 8 is a partially enlarged view showing the second embodiment of the automatic transmission according to the present invention.

Gear ratio switching means 40 in this embodiment
The sleeve and hub 142 to the input shaft 1
41 (FIG. 1), a gear shift arm 42 and a gear shift fork 44 that are moved in the axial direction, and a push solenoid 46 and a return spring 48 as drive sources thereof.
It consists of and. The gear shift arm 42 and the gear shift fork 44 are integrated, and the sleeve and hub 142 can be moved by the pressing force of the push solenoid 46 and the restoring force of the return spring 48. A push-pull solenoid may be used instead of the push solenoid 46. In this case, the return spring 48 can be omitted.

FIG. 9 is a partially enlarged view showing the third embodiment of the automatic transmission according to the present invention.

Gear ratio switching means 50 in this embodiment
The sleeve and hub 142 to the input shaft 1
A gear shift arm 52 and a gear shift fork 54, which move in the axial direction of 41 (FIG. 1), and a stepping motor 56 as a drive source thereof. The pinion 58 is attached to the rotation shaft of the stepping motor 56.
The gear shift arm 52 is provided with a rack 59 that meshes with the pinion 58. The gear shift arm 52 and the gear shift fork 54 are driven by the rotational force of the stepping motor 56 to move the sleeve and hub 142.
Can be moved.

FIG. 10 is a partially enlarged view showing a fourth embodiment of the automatic transmission according to the present invention.

Gear ratio switching means 60 in this embodiment
The sleeve and hub 142 to the input shaft 1
41 (FIG. 1), a gear shift lever 62, a gear shift arm 63, and a gear shift fork 64 as switching members 61 for moving in the axial direction, and a push solenoid 66 and a return spring 68 as drive sources 65 thereof.
And a gear shift cable 70 that transmits the driving force. The gear shift cable 70 has a structure in which a wire is inserted into a tube and has flexibility. That is, the driving force generated by the push solenoid 66 or the return spring 68 is transmitted to the gear shift lever 62, the gear shift arm 63, and the gear shift fork 64 via the gear shift cable 70.
In the present embodiment, by utilizing the flexibility of the gear shift cable 70, the drive source 65 can be installed at any position apart from the transmission 14 (FIG. 1). For example, by installing the drive source 65 in a small gap,
Effective use of space (miniaturization) can be achieved.

FIG. 11 is a partially enlarged view showing a fifth embodiment of the automatic transmission according to the present invention.

In this embodiment, the drive source 65 (FIG. 10) in the fourth embodiment is replaced with the drive source 80. The drive source 80 is composed of a stepping motor 82 and a ball screw 84.

Needless to say, the first to fifth embodiments described above are merely examples. Therefore, the present invention is not limited to these examples. For example, the transmission may be of a type other than the constant mesh type, or may be of a third speed or higher.

[0037]

According to the automatic transmission of claim 1,
Various sensors detect the number of revolutions, vehicle speed, shift position, accelerator opening, etc., and based on these values, the controller outputs a gear ratio switching signal and a traveling motor drive signal, so a simple configuration is possible. Further, it is possible to realize automatic shift of an electric vehicle with high energy efficiency. Moreover, since the existing transmission can be used as it is, manufacturing convenience and economy can be improved.

According to the automatic transmission of the second aspect, since the gear ratio switching means is constituted by using the flexible cable for transmitting the driving force, the drive source is installed at an arbitrary position apart from the transmission. it can. Therefore, by installing the drive source in a small gap or the like, it is possible to effectively use the space (downsize).

According to the automatic transmission of the third aspect of the invention, since the controller makes the rotational speeds of the meshing gears equal when switching the gear ratio of the transmission, the gears can be smoothly meshed. Yes, this reduces gear damage and wear.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of a first embodiment of an automatic transmission according to the present invention.

FIG. 2 is a partially enlarged view showing a gear ratio switching means in the automatic transmission apparatus of FIG.

FIG. 3 is a flowchart showing an example of an operation at the time of starting in the automatic transmission apparatus of FIG.

FIG. 4 is a flowchart showing an example of an operation during traveling in the automatic transmission device of FIG.

FIG. 5 is a graph showing a shift diagram for determining whether to shift gears based on a vehicle speed and an accelerator opening.

6 is a flowchart showing a synchronizing operation A in FIG.

FIG. 7 is a flowchart showing a synchronizing operation B in FIG.

FIG. 8 is a partially enlarged view showing a second embodiment of the automatic transmission according to the present invention.

FIG. 9 is a partially enlarged view showing a third embodiment of the automatic transmission according to the present invention.

FIG. 10 is a partially enlarged view showing a fourth embodiment of the automatic transmission according to the present invention.

FIG. 11 is a partially enlarged view showing a fifth embodiment of the automatic transmission according to the present invention.

[Explanation of symbols]

 10 Automatic Transmission 12 Motor for Driving 13 Drive Shaft 14 Transmission 16 Speed Sensor 18 Vehicle Speed Sensor 20 Shift Lever 22 Shift Sensor 24 Accelerator Sensor 26 Controller 28, 40, 50, 60 Gear Ratio Switching Means 32 Drive Circuit 30 Battery n Running Motor speed V Vehicle speed S Running state (shift position) A Accelerator opening G Gear ratio switching signal d Driving motor drive signal

Claims (3)

[Claims] 1. A transmission for transmitting power generated by a traveling motor to a drive shaft at a predetermined gear ratio, a rotation speed sensor for detecting a rotation speed of the travel motor, a vehicle speed sensor for detecting a vehicle speed, and a shift. A shift sensor for detecting a running state set by a lever, an accelerator sensor for detecting an accelerator opening, a rotation speed detected by the rotation speed sensor, a vehicle speed detected by the vehicle speed sensor, and a shift sensor detected by the shift sensor. A controller that outputs a gear ratio switching signal and a traveling motor drive signal based on the traveled state, the opening detected by the accelerator sensor, etc., and the transmission gear according to the gear ratio switching signal output from the controller. Gear ratio switching means for switching the ratio, and the traveling according to the traveling motor drive signal output from the controller And a drive circuit that supplies electric power of a battery to an electric motor for an electric vehicle. 2. A drive source, wherein the gear ratio switching means is driven by a gear ratio switching signal output from the controller to generate a driving force, and a flexibility for transmitting the driving force generated by the driving source. And a switching member that switches the gear ratio of the transmission by the driving force transmitted through the cable.
An automatic transmission device for an electric vehicle according to claim 1. 3. The electric vehicle according to claim 1, wherein the controller outputs the traveling motor drive signal so as to equalize rotational speeds of meshing gears when the gear ratio of the transmission is switched. Gearbox.