JPH07147710A - Motor driving controller for electric vehicle - Google Patents

Abstract

PURPOSE:To provide a motor control device that operates in synchronism with car speed to vary the speed of an electric vehicle having no clutch. CONSTITUTION:Positional signals Sn, Sd, Sr corresponding to each position from a shift switch 23 turned on when a shift lever 21 is placed at a position N, a position D or a position R, an accelerator signal Ac from an accelerator pedal 24 and a car speed signal V from a car speed sensor 25 are input to a controller 22, and a specified control program is carried out, thus normally controlling the rotational speed of a motor M during a period from the state of rotational stoppage to the state of maximum rotational speed on the basis of the manipulated variable of an accelerator by a driver. Rotational speed control synchronized with car speed is conducted to the motor M when a neutral state is selected during travelling, and rotational speed control synchronized with car speed is released when the neutral state is released during a variable speed stroke from a neutral position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention realizes a neutral state without providing a power on / off clutch by an electric motor capable of speed control from a rotation stopped state to a maximum rotation speed state based on an accelerator operation amount of a driver. However, the present invention relates to an electric motor drive control device that enables a gear shift during traveling in an electric vehicle that has a transmission that shifts gears by switching a shift position by a shift position switching mechanism.

[0002]

2. Description of the Related Art An electric motor used as a power source for an electric vehicle is a vehicle with an accelerator pedal released to enable speed control from a rotation stop state to a maximum rotation speed state based on a driver's accelerator operation amount. In this state, the rotation is stopped. Therefore, in an electric vehicle provided with a clutch for power discontinuity between the electric motor and the transmission that changes the output of the electric motor and transmits the output to the drive wheels, when the transmission is started, the neutral state is changed to the start gear selection state. In order to do so, it is necessary to engage the power on / off clutch. However, since the pump that drives the power on / off clutch is stopped while the vehicle is stopped, the start gear position selection state cannot be entered until the start operation of depressing the accelerator pedal, resulting in problems such as start delay and start shock. It is possible to constantly drive the pump in order to solve this problem, but in that case, not only a cost disadvantage is caused but also a serious problem that the traveling distance is shortened in an electric vehicle using a battery as a power source Occurs.

Therefore, in a transmission for an electric vehicle, when a driver manually performs a shift operation, the neutral state is switched to the start gear stage selection state through a shift position switching mechanism such as a dog clutch and a synchronous meshing mechanism. It is common to use a transmission of the type described.

[0004]

When an electric vehicle using a transmission of the type described above is constructed without a clutch for discontinuing power, a neutral position is selected by the driver during traveling to bring the vehicle into a neutral state. Then, since power transmission is cut off in the transmission, the relative rotation speed difference generated between the gear connected to the input shaft and the gear connected to the output shaft, which is transmitted from the electric motor as the rotation of the electric motor decreases, is caused by the shift position. It cannot be absorbed by the switching mechanism, which makes shifting impossible.

In order to solve this inconvenience, it is conceivable to control the rotation speed of the electric motor in synchronization with the vehicle speed when the neutral position is selected during traveling. But,
It is difficult to completely eliminate the relative rotational speed difference only by instantaneously performing the rotational speed control in synchronization with the vehicle speed, and a certain synchronous control rotational speed range is achieved. If the shift operation is performed from the neutral position without changing the state having such a synchronous control rotation speed range and the gear shift is attempted, the rotation speed control works in the direction of excessively increasing the synchronization force in the shift position switching mechanism. As a result, poor gear shifting and early wear of the shift position switching mechanism may occur.

It is an object of the present invention to provide an electric motor drive control device capable of shifting during running in an electric vehicle having a structure in which a clutch for discontinuing power is not provided.

[0007]

To this end, according to the present invention, as shown in the concept of FIG. 1, a rotation speed control is performed from a rotation stop state to a maximum rotation speed state based on an accelerator operation amount of a driver. A vehicle speed detecting means for detecting a vehicle speed in an electric vehicle that realizes a neutral state without providing a power on / off clutch by a possible electric motor, and has a transmission that shifts gears by shifting a shift position by a shift position switching mechanism, Shift position detecting means for detecting a shift position of the transmission while the vehicle is traveling, and at the time of detecting a neutral position corresponding to the neutral state during traveling, rotational speed control is performed for the electric motor in synchronization with the vehicle speed, and a neutral position from the neutral position is detected. Rotation speed control means for canceling rotation speed control in synchronization with the vehicle speed when the neutral state is released during the shift stroke It is characterized in that made comprises.

[0008]

According to the present invention, when the driver performs a shift operation after selecting a neutral position while driving and then performing a shift operation, the rotation speed control means is provided when the vehicle of the transmission for an electric vehicle is running. When the neutral position corresponding to the neutral state is detected by the shift position detecting means for detecting the shift position, the rotational speed control that is synchronized with the vehicle speed is started for the electric motor, and the neutral state is released during the shift stroke from the neutral position. At this time, the rotation speed control synchronized with the vehicle speed is released. By this rotation speed control, the shift position switching mechanism absorbs the relative rotation speed difference generated between the gear connected to the input shaft and the gear connected to the output shaft, the power being transmitted from the electric motor as the electric motor rotation decreases. At the same time, it is possible to prevent the synchronization force in the shift position switching mechanism mechanism from becoming excessive.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 2 is a diagram showing the configuration of a first embodiment of an electric motor drive control device for an electric vehicle according to the present invention, in which 1 denotes an input shaft and 2 denotes an output shaft. The input shaft 1 is connected to the electric motor M at the right end in the figure, and the output shaft 2 is juxtaposed in parallel with the input shaft 1. The intermediate shaft 3 is provided in a butt relationship coaxially with the input shaft 1,
These two shafts are connected by a one-way clutch OWC, and the one-way clutch is arranged in a direction in which the rotation of the electric motor M can be transmitted from the input shaft 1 to the intermediate shaft 3.

A one-way clutch OW is mounted on the intermediate shaft 3.
The first speed input gear 4 and the reverse input gear 5 are sequentially connected from the side farther from C, and the output shaft 2 is aligned with these gears 4 and 5.
A first speed output gear 6 and a reverse output gear 7 are rotatably supported on the upper side. The first speed output gear 6 is directly meshed with the first speed input gear 4, and the reverse output gear 7 is meshed with the reverse input gear 5 through the idler gear 8.

A dog clutch D / C serving as a selected position switching mechanism is interposed between the gears 6 and 7, and the dog clutch has a well-known configuration. When the coupling sleeve is set to a neutral position indicated by N, When both the gears 6 and 7 are not connected to the output shaft 2 but leftwardly moved to the first speed position,
When the first speed output gear 6 is connected to the output shaft 2 and the reverse position R is set, the reverse output gear 7 is connected to the output shaft 2.

A parking gear 9 is further provided on the output shaft 2.
Also, the second speed output gear 10 is bound and aligned with the second speed output gear 10 to rotatably support the second speed input gear 11 on the input shaft 1. The input shaft 1 is further provided with this second speed input gear 11
A hydraulically actuated clutch O / C is provided in order to drive-couple to the input shaft 1 as appropriate.

A differential gear 12 is provided in parallel to the output shaft 2, and the differential gear 12 is drivingly coupled to the output shaft 2 via a final drive gear set 13. Then, the axles 14L and 14R are extended from the differential gear 12, and these axles are respectively coupled to the left and right wheels not shown.

The coupling sleeve of the dog clutch D / C is to be stroked by the driver via the shift lever 21, and at the N position of the shift lever 21, the coupling sleeve is set to the neutral position and the D of the shift lever 21 is moved.
At the position, the coupling sleeve is moved leftward to the forward position, and at the R position of the shift lever 21, the coupling sleeve is moved rightward to the retracted position.

The transmission having the above construction can be in a neutral state in which power cannot be transmitted at the N position, and
At the position, the forward first speed or the second forward speed can be selected, and at the R position, the reverse speed can be selected.

A controller 22 is provided to control the rotational speed of the electric motor M that drives the above-mentioned transmission. As shown in FIG. 2, the controller 22 sends position signals Sn, Sd corresponding to respective positions from the shift switch 23 which is turned on when the shift lever 21 is in the N position, the D position or the R position.
, Sr are input, the accelerator signal Ac is input from the accelerator pedal 24, and the vehicle speed signal V is input from the vehicle speed sensor 25.

The controller 22 basically applies electric power corresponding to the depression amount of the accelerator pedal 24 from the battery E to the electric motor M on the basis of the accelerator signal Ac, thereby controlling the rotation speed of the electric motor M. Then, by executing the control program of FIG. 3 based on the input signals, the rotational speed control for shifting after selecting the N position during traveling is performed.

That is, in the control program of FIG. 2 which is repeatedly executed by the timed interrupt, first, step 101
The vehicle speed V read from the vehicle speed sensor 25 at the predetermined vehicle speed V ₀
(For example, 2 km / h) is determined, and the predetermined vehicle speed V _{0 is} determined.
The self-loop is repeated until the vehicle speed reaches, and the control proceeds to step 102 after reaching the predetermined vehicle speed V ₀ .

At step 102, the presence or absence of the position signal Sn is determined. This determination is NO during normal traveling, and the control advances to step 103, which is YES only when the N position is selected during traveling.

At step 103, it is judged if the position signal Sn is turned off during the shift stroke. This determination is NO during normal traveling, and the control is step 1
In step 104, the position signal S
Determine whether d or Sr is present. Therefore, during normal driving, YES in step 101-NO-103 in step 102
The loop of YES-105-101 of NO-104 is repeated, and the rotation speed of the electric motor M is controlled based on the accelerator signal Ac in step 105.

When the driver performs an operation of selecting the N position during this traveling, step 102 becomes YES and the control advances to step 106. At step 106, the rotation speed of the electric motor M synchronized with the vehicle speed is reached. Performs control (vehicle speed synchronous rotation speed control). This vehicle speed synchronous rotation speed control is continued until the position signal Sn is turned off during the shift stroke and the control is advanced to YES-107 of NO-103 of step 102 and released. As a result, the rotation speed of the gear that is coupled to the input shaft that is transmitted from the electric motor M gradually decreases as the rotation speed of the electric motor decreases, and the relative rotational speed difference with the gear on the transmission side that meshes with the gear decreases. Since the torque becomes 0 when the vehicle speed synchronous rotation speed control is released, there is no problem that the dog clutch D / C has an excessive synchronous force, resulting in poor gear shifting or early wear.

When the gear shift is completed and the position signal Sd or Sr is turned ON after the release of the vehicle speed synchronous rotation speed control, step 104 becomes YES and step 105 is selected. Based on the accelerator signal Ac in step 105. The rotation speed of the electric motor M is controlled. It should be noted that the position signal Sr is included in the determination condition of step 104 in the present embodiment also in the case where "the N position selection operation is performed during the backward traveling and then the R position selection operation is performed again to perform the backward traveling". Is to be applicable.

The summary of the above control is summarized in the following table.

[Table 1]

[0024]

As described above, the electric motor drive control device for an electric vehicle according to the present invention, when the driver once selects the neutral position during traveling and puts it in the neutral state and then performs the shift operation, the rotational speed control means is provided. When the shift position detecting means for detecting the shift position of the transmission for the electric vehicle during traveling of the vehicle detects the neutral position corresponding to the neutral state, the rotation speed control in synchronization with the vehicle speed is started for the electric motor, and the neutral position is set. When the neutral state is released during the shift stroke from the position, the rotational speed control synchronized with the vehicle speed is released, and this rotational speed control is coupled to the input shaft to which power is transmitted from the electric motor as the electric motor rotation decreases. The shift position switching mechanism absorbs the relative rotational speed difference generated between the gear and the gear connected to the output shaft. Together, can be synchronized force of the shift position switching mechanism mechanism is prevented from becoming excessive.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of the present invention.

FIG. 2 is a diagram showing a configuration of a first embodiment of an electric motor drive control device for an electric vehicle of the present invention.

FIG. 3 is a flowchart showing a control program for controlling the rotation speed of an electric motor by the controller of the example.

[Explanation of symbols]

 1 Input Shaft 2 Output Shaft 3 Intermediate Shaft 4 1st Speed Input Gear 5 Reverse Gear Input 6 1st Speed Output Gear 7 Reverse Output Gear 8 Idler Gear 10 2nd Speed Output Gear 11 2nd Speed Input Gear 12 Differential Gear 13 Final Drive Gear 14L Axle 14R Axle 22 Controller 23 Shift switch 24 Accelerator pedal 25 Vehicle speed sensor E Battery D / C dog clutch (shift position switching mechanism) OWC One-way clutch O / C Hydraulic actuation clutch OR / C Overrun clutch D / C (F) Forward dog clutch ( Switching clutch) D / C (R) Reverse dog clutch (switching clutch) OWC / F Forward one-way clutch OWC / R Reverse one-way clutch

Front page continuation (72) Inventor Isamu Onuma 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.

Claims (1)

[Claims] 1. A neutral state is realized by a motor capable of controlling a rotation speed from a rotation stop state to a maximum rotation speed state based on a driver's accelerator operation amount, and a neutral state is realized without providing a power on / off clutch, and shift position switching is performed. In an electric vehicle equipped with a transmission that shifts gears by switching a shift position by a mechanism, vehicle speed detecting means for detecting a vehicle speed, shift position detecting means for detecting a shift position of the transmission while the vehicle is traveling, and When the neutral position corresponding to the neutral state is detected, rotational speed control is performed on the electric motor in synchronization with the vehicle speed, and when the neutral state is released during the shift stroke from the neutral position, the rotational speed control is released in synchronization with the vehicle speed. A motor drive control device for an electric vehicle, comprising: a rotation speed control means.