JP5397922B2 - Electric car - Google Patents

Description

  The present invention relates to an electric vehicle such as a forklift that travels by driving a travel motor with electric power stored in a battery.

  As an electric vehicle, for example, a standing-ride type forklift that is operated while an operator is standing is known. As shown in FIG. 1, the forklift 1 is provided at a lower portion of the vehicle body 2, a mast 50, 63 that slides back and forth with respect to the vehicle body 2, a pair of forks 66 that move up and down along the mast 50, 63. Drive wheels 7. The vehicle body 2 has a driver's seat 5 in which the operator stands up. The driver's seat 5 has an operation lever 69 for performing various operations in addition to the accelerator lever 6 and the foot-deadman brake 8. And a handle 68 are provided. The drive wheel 7 is turnably attached to the vehicle body 2 and has a function as a steered wheel.

  As shown in FIG. 2, the forklift 1 moves forward at a speed corresponding to the tilt angle θ1 when the accelerator lever 6 is tilted forward from the neutral position, and moves backward at a speed corresponding to the tilt angle θ2 when tilted backward. Further, when the accelerator lever 6 is returned to the neutral position, the forklift 1 performs neutral regeneration control and decelerates to a predetermined minute speed (for example, 1 km / h) (for example, see Patent Document 1).

  Further, in the forklift 1, the traveling motor is regeneratively controlled with a regenerative force larger than the regenerative force of the neutral regenerative control by tilting the accelerator lever 6 in the direction opposite to the traveling direction during forward or reverse travel, and the brake is applied. Done. Applying the brake by such an operation is called “plugging operation”. In a stand-up forklift that operates with the operator standing, the operator frequently uses this plugging operation when braking.

  By the way, from the viewpoint of improving safety, the forklift 1 detects when the operator removes his / her seat and detects the absence of the seat, thereby invalidating the operation of the accelerator lever 6 and the cargo handling operation such as raising and lowering the fork 4. (For example, refer to Patent Document 2). However, when the conventional forklift 1 performs the control at the time of leaving the seat, when the operator's leaving is detected due to a malfunction, the following problem may occur.

  If any abnormality occurs and the operator's absence is detected erroneously, the operation of the accelerator lever 6 becomes invalid, and the forklift 1 decelerates with a constant regenerative force under neutral regenerative control. For this reason, even if the forklift 1 approaches an obstacle such as a wall and the operator tries to decelerate by performing a plugging operation based on the judgment of the heel, the operation of the accelerator lever 6 is invalidated, so the vehicle decelerates beyond a predetermined speed. There was a risk of colliding with a wall without doing so.

  Even during the away control, the forklift 1 can be stopped by mechanically locking the drive wheels 7 by operating the brake 8. However, in the standing type forklift 1, the brake is often applied by the above-described plugging operation, and the brake 8 is used when parked and is not used during traveling. Therefore, it is very difficult to operate the brake 8.

JP-A-8-256401 JP-A-10-313502

  The problem to be solved by the present invention has been made in view of the above circumstances, and is to provide an electric vehicle capable of improving the safety of the control at the time of leaving.

In order to solve the above problems, an electric vehicle according to the present invention is:
An absence detection unit that detects whether the operator is away, or
A travel motor for driving the drive wheels;
A travel determining means for determining the traveling direction and the target speed of the drive wheel;
A control unit for regenerative control or power running control of the traveling motor;
And a progression detection unit for detecting the traveling direction of the drive wheels,
The control unit
When the absence detection unit does not detect the absence of the operator, the normal control is performed, and when the absence detection unit detects the absence of the operator , the absence detection unit is configured to perform the control when leaving the seat.
Normal control is
Power running control and regenerative control based on the determination of the progress determining means,
When leaving the seat,
Despite the determination of progression detection unit, first, regenerative controlled by first regenerative power, then the traveling direction of the driving wheels detected by the traveling detecting unit sometimes progress determining means in the reverse direction is determined, than first regenerative power and regenerative control with a large second regenerative force, the traveling direction of the detected driving wheel in the traveling detecting unit sometimes progress determining means in the opposite direction is not determined, times remains first regenerative force Live control.

  Since the electric vehicle according to the present invention is configured as described above, even if some abnormality occurs and the operator's absence is erroneously detected, the operator is in a direction opposite to the traveling direction of the drive wheels. If the travel determining means is determined in the direction, the traveling motor can be regeneratively braked with a large regenerative force, so that the risk of collision with a wall or the like can be greatly reduced. That is, in the conventional forklift, the operation of the progress determining means is invalidated even if the absence of seat is detected by mistake, but in the forklift of the present invention, the operation of the progress determining means is not invalidated and the plugging that the operator is accustomed to is not used. By enabling only the operation, the vehicle can be safely stopped at the discretion of the operator. Therefore, even if the operator mistakenly tilts the accelerator lever in the same direction as the traveling direction, the traveling motor is regeneratively controlled, so that the vehicle can be stopped safely.

Preferably,
The electric vehicle is a standing forklift that is operated while an operator is standing,
The travel determination means comprises an accelerator lever that determines the travel direction and target speed of the drive wheel by tilting forward and backward with the operator's hand,
The absence detection unit includes a floor switch provided at the operator's foot.

  The above-described plugging operation is frequently used in a stand-up forklift that is operated while the operator is standing. This forklift is provided with a foot-operated deadman type brake. The deadman type brake can run when an operator steps on the brake lever, and stops when the brake lever is released without stepping on the brake lever. For this reason, the deadman type brake is usually not used for decelerating the vehicle speed, but is used as a parking brake for reliably stopping the vehicle at the time of parking. Therefore, the operator frequently uses the above plugging operation when decelerating the vehicle speed. Therefore, the forklift according to the present invention is particularly effective for a stand-up forklift that frequently uses a plugging operation.

Preferably,
The control means
Change the 2nd regenerative power according to the tilt angle of the accelerator lever,
When the tilt angle is large, the second regenerative force changes so as to increase, and when the tilt angle is small, the second regenerative force changes so as to decrease.

  When there is a risk of colliding with a wall or the like, the operator tries to increase the regenerative power by tilting the accelerator lever greatly. Therefore, the safety can be further improved by changing the second regenerative force according to the inclination angle of the accelerator lever.

  In the electric vehicle of the present invention, even if the absence of seat is detected by mistake, the operation of the progress determining means is not invalidated, and only the plugging operation that the operator is accustomed to is validated. You can stop safely. Therefore, the electric vehicle according to the present invention can improve the safety by the control at the time of leaving the seat.

It is a perspective view which shows the reach type forklift which concerns on this invention. It is a side view which shows operation | movement of an accelerator lever. It is a block diagram which shows the main structures. It is a flowchart which shows control operation. It is explanatory drawing which shows control operation.

  Hereinafter, an electric vehicle according to the present invention will be described with reference to the drawings. In the present embodiment, the electric vehicle is a standing riding forklift that is operated while the operator is standing.

  As shown in FIG. 1, the reach forklift includes a left and right straddle arm 62 that extends to the front side of the vehicle body 2. The reach forklift includes a carriage 64 that can be moved back and forth along the left and right straddle arms 62. A pair of outer masts 63 are vertically provided on the carriage 64. An inner mast 50 is erected on the inner side of each outer mast 63. The inner mast 50 moves up and down while being guided by the outer mast 63. A lift cylinder 70 is erected on the carriage 64 along the outer mast 63. The lift cylinder 70 and the inner mast 50 are combined, and the inner cylinder 50 moves up and down along the outer mast 63 as the lift cylinder 70 expands and contracts.

  The reach forklift is provided with a lift bracket 65. A pair of left and right forks 66 are supported on the lift bracket 65 so as to be tiltable. As the lift cylinder 70 expands and contracts, the inner mast 50 moves up and down, and the fork 66 moves up and down together with the lift bracket 65 accordingly. Further, the lift bracket 65 is provided with a tilt cylinder (not shown), and the fork 66 is tilted as the tilt cylinder expands and contracts. A reach cylinder (not shown) is provided across the vehicle body 2 and the carriage 64. As the reach cylinder (not shown) expands and contracts, the carriage 64 moves back and forth along the straddle arm 62.

  The left rear portion of the vehicle body 2 is a device storage chamber 61 that is closed by a door that can be opened and closed. Inside the device storage chamber 61, a hydraulic oil tank, a hydraulic oil pump, a battery 16, which will be described later, and a travel motor 17 (FIG. 3). ) Etc. are installed. The right rear portion of the vehicle body 2 is a driver's seat 5 that is formed to be opened rearward, and the operator gets on the driver's seat 5 while standing. The top cover 67 is covered from the upper part of the device storage room 61 to the front of the driver's seat 5. Drive wheels 7 are provided at the lower part of the vehicle body 2. The drive wheel 7 is attached to the vehicle body 2 so as to be able to turn, and also has a function as a steering wheel.

  On the top cover 67, a steering wheel 68 for steering is provided at the left position of the driver's seat 5, and an operation lever 69 for operating the fork, a traveling direction of the vehicle, and a front position of the driver's seat 5 are provided. An accelerator lever (progress determination means) 6 for determining the target speed is provided. At the foot of the driver's seat 5, a stepping and deadman type brake 8 and a floor switch (seating detection unit) 9 are provided.

  As shown in FIG. 2, the traveling direction of the vehicle is determined according to the tilt direction of the accelerator lever 6. That is, when the accelerator lever 6 is tilted forward (forward tilt), the forklift moves forward, and when the accelerator lever 6 is tilted rearward (backward tilt), the forklift moves backward. The accelerator lever 6 is biased to the neutral position by biasing means (not shown) such as a coil spring. Further, a target speed of the vehicle (hereinafter referred to as a target speed) is determined according to the inclination angles θ1 and θ2 of the accelerator lever 6.

  As shown in FIG. 3, the vehicle main body 2 houses a traveling motor 17 connected to the drive wheels 7 through a transmission gear (not shown), an inverter circuit 15 that drives the traveling motor 17, a battery 16, and the like. The control unit 11 performs power running control or regenerative control of the traveling motor 17 via the inverter circuit 15. In the power running control, the electric power of the battery 16 is supplied to the traveling motor 17 via the inverter circuit 15. On the other hand, in the regeneration control, the electric power generated by the traveling motor 17 is returned to the battery 16 via the inverter circuit 15.

  The brake 8 is provided independently from the control unit 11. When the operator operates the brake 8, the drive wheel 7 is mechanically locked. Thereby, the forklift 1 stops regardless of the inclination of the accelerator lever 6.

  The accelerator lever 6 is connected to the control unit 11. When the accelerator lever 6 is tilted forward from the neutral position, the control unit 11 moves the drive wheel 7 forward, and when the accelerator lever 6 is tilted backward, the control unit 11 moves the drive wheel 7 backward. The accelerator lever 6 outputs a signal corresponding to the tilt angles θ1 and θ2, and the control unit 11 controls the target speed based on this signal.

  The away switch detection floor switch 9 is provided so as to cover almost the entire floor of the driver's seat 5. For this reason, when the operator gets on the forklift 1, the operator's weight is applied to the floor switch 9 for detecting the absence of seat, and the floor switch 9 for detecting the absence of seat outputs a signal indicating that the operator is not away. On the other hand, when the operator's weight is not applied, that is, when the operator is away, the away detection floor switch 9 outputs a signal indicating that the operator is away.

  The progress detection unit 12 detects the traveling direction (forward or reverse) and speed of the vehicle based on a rotational speed signal from a rotary encoder or the like provided on the drive wheel 7. When the drive wheel 7 moves forward, the vehicle moves forward, and when the drive wheel 7 moves backward, it is recognized that the vehicle moves backward. The progress detection unit 12 outputs a signal related to the traveling direction and the vehicle speed to the control unit 11.

  As shown in FIG. 4, the control unit 11 normally controls the traveling motor 17 based on the tilt direction (forward tilt or rear tilt) of the accelerator lever 6, tilt angles θ <b> 1, θ <b> 2, and a signal from the floor switch 9 for detecting absence. Control when you are away.

  The control unit 11 performs normal control and leaving control as follows. When the absence of the operator is not detected (“No” in step S1), the control unit 11 controls the traveling motor 17 based on the normal control (step S2).

Normal control is performed as follows.
(1) When the accelerator lever 6 is tilted forward or backward from the neutral position, the power running control is performed so that the vehicle speed matches the target speed corresponding to the tilt angles θ1 and θ2 of the accelerator lever 6.
(2) When the accelerator lever 6 is returned to the neutral position, regenerative control is performed so as to decelerate to a predetermined minute speed (for example, 1 km / h).
(3) When the accelerator lever 6 is tilted in the direction opposite to the traveling direction of the drive wheel 7 during forward or reverse travel (when the drive wheel 7 is moving forward, the accelerator lever 6 is tilted backward, or the drive wheel 7 When the vehicle is moving backward, the accelerator lever 6 is tilted forward), and regenerative control is performed until the vehicle speed becomes zero. Thereafter, the drive wheel is advanced according to the tilt direction of the accelerator lever 6, and the accelerator lever 6 Power running control is performed so as to match the target speed according to the inclination angles θ1 and θ2.

  The controller 11 controls the traveling motor 17 based on the normal control until the absence of the operator is detected based on the floor switch 9 for detecting the absence of seat (steps S1 to S2).

  When the absence of the operator is detected (“Yes” in step S1), the control unit 11 starts a time counter (not shown). Then, when the time counter outputs that a predetermined time (for example, 2 seconds) has passed (“Yes” in step S3), the traveling motor 17 is controlled based on the away time control (steps S4 to S7). If the time counter does not output that the predetermined time has elapsed (“No” in step S3), the traveling motor 17 is controlled based on the normal control. Note that the reason for providing a delay of a predetermined time before the control at the time of leaving the seat is that the operator's foot may be separated from the floor switch 9 for detecting the leaving for a short time due to a malfunction, and in that case, a particularly dangerous state It is because it does not become.

The away control is performed as follows.
The control unit 11 performs regenerative control of the traveling motor 17 with the first regenerative force W1 with respect to the traveling direction of the drive wheel 7 detected by the progress detection unit 12 (step S4). That is, the control unit 11 performs regenerative control with the force in the reverse direction when the drive wheel 7 is moving forward, and performs regenerative control with the force in the forward direction when the drive wheel 7 is moving backward.

  Next, the control unit 11 determines whether the accelerator lever 6 is tilted in the direction opposite to the traveling direction of the drive wheel 7 detected by the progress detecting unit 12 (step S5). That is, the control unit 11 determines whether the accelerator lever 6 is tilted backward when the driving wheel 7 is moving forward, or whether the accelerator lever 6 is tilted forward when the driving wheel 7 is moving backward. .

  When the accelerator lever 6 is tilted in the direction opposite to the traveling direction of the drive wheel 7 detected by the progress detection unit 12 (“Yes” in step S5), the control unit 11 determines that the first regenerative force W1 is larger. The traveling motor 17 is regeneratively controlled with the regenerative power W2 (step S6).

  When the accelerator lever 6 is not tilted in the direction opposite to the traveling direction of the drive wheel 7 detected by the progress detector 12 (“No” in step S5), the controller 11 travels with the first regenerative power W1. The motor 17 is regeneratively controlled (step S7). Here, the case where the accelerator lever 6 is not inclined in the direction opposite to the traveling direction of the drive wheel 7 is the case where the accelerator lever 6 is inclined in the same direction as the traveling direction, or the accelerator lever 6 is in the neutral position. Refers to cases.

  Then, the controller 11 decelerates to a very small speed (for example, 1 km / h) that is a target speed, and then determines whether or not the vehicle is stopped by running resistance (step S8), and performs away time control until the vehicle stops (step S8). S5 to S8).

Based on FIG. 5, the case where the control at the time of leaving the seat is performed when the forklift is normally traveling at the speed V1 will be described.
The away switch detection floor switch 9 detects the absence of the operator at time t0 (step S1 in FIG. 4), and then, from time t0 to time t1 (for example, 2 seconds) with the absence detected. (Step S3 in FIG. 4).

  The controller 11 starts regenerative control of the travel motor 17 with the first regenerative force W1 at time t1 (step S4 in FIG. 4). Accordingly, the forklift is decelerated at the first acceleration G1 in the direction opposite to the traveling direction from time t1.

  Thereafter, for example, when an obstacle approaches and the operator determines to greatly decelerate by the plugging operation, at time t2, the operator tilts the accelerator lever 6 in the direction opposite to the traveling direction (“Yes” in step S5 in FIG. 4). ). Then, the control part 11 starts the regeneration control of the traveling motor 17 with the 2nd regeneration force W2 larger than the 1st regeneration force W1 (step S6 of FIG. 4). Therefore, the forklift decelerates at a second acceleration G2 greater than the first acceleration G1 in the direction opposite to the traveling direction from time t2. Therefore, the vehicle can be stopped earlier than the deceleration (the one-dot chain line in FIG. 5) while the first acceleration G1 of the first regeneration force W1 remains unchanged.

  Here, the control unit 11 changes the second regenerative force W2 according to the inclination angles θ1 and θ2 of the accelerator lever 6. That is, when the inclination angles θ1 and θ2 are large, the second regenerative force W2 is large, and when the inclination angles θ1 and θ2 are small, the second regenerative force W2 is small. Therefore, if the accelerator lever 6 is tilted greatly, the time until the vehicle stops can be reduced.

  When the operator tilts the accelerator lever 6 in the same direction as the traveling direction, or when the accelerator lever 6 is set to the neutral position (“No” in step S5 in FIG. 4), the control unit 11 determines the first regenerative power W1. The traveling motor 17 is regeneratively controlled (step S7 in FIG. 4), and the vehicle is stopped.

  Therefore, in the forklift according to the present invention, the operator determines the travel determination means in the direction opposite to the traveling direction of the drive wheels even when some sort of abnormality occurs and the operator's absence is erroneously detected. When the plugging operation is performed, the traveling motor can be regeneratively braked with a large regenerative force, so that the danger of colliding with a wall or the like can be greatly reduced.

As mentioned above, although preferred embodiment of the electric vehicle which concerns on this invention was described, this invention is not limited to these structures.
For example, in the case of a seated forklift that an operator sits on a seat and drives, the absence detection unit is disposed on the seat surface of the seat, and the progress determination means includes a lever that determines the traveling direction and a stepping type that determines the target speed It consists of a pedal.
The predetermined minute speed is not limited to 1 km / h, and can be any speed at which the forklift stops due to running resistance.

1 Forklift 2 Vehicle body 6 Accelerator lever
7 Drive wheel 8 Brake 9 Floor switch for detection of absence (seating detection unit)
11 Control Unit 12 Progression Detection Unit 17 Traveling Motor

Claims (3)

An absence detection unit that detects whether the operator is away, or
A travel motor for driving the drive wheels;
A travel determining means for determining a travel direction and a target speed of the drive wheel;
A control unit for regenerative control or power running control of the travel motor;
And a progression detection unit for detecting the traveling direction of the driving wheel,
The controller is
When the absence detection of the operator is not detected by the absence detection unit, the normal control is performed, and when the absence detection of the operator is detected by the absence detection unit, the control is performed at the time of leaving.
The normal control is
Power running control and regenerative control based on the determination of the progress determining means,
The control when leaving the seat is
Despite the determination of the traveling sensing unit, first, regenerative controlled by first regenerative power, then the the traveling direction of the detected said drive wheel in advanced detection unit the traveling determining means in the opposite direction determination sometimes is, the first regenerative power than to regenerative control with a large second regenerative force, sometimes above the traveling direction of the detected said drive wheel in advanced detection unit the traveling determining means in the opposite direction is not determined, electric vehicle, characterized in that the regenerative control remains the first regenerative power.
The electric vehicle according to claim 1 comprises a standing-fork forklift that is operated in a state where the operator stands,
The travel determination means comprises an accelerator lever that determines the travel direction and target speed of the drive wheel by tilting forward and backward with the operator's hand,
The electric vehicle according to claim 1, wherein the absence detection unit comprises a floor switch provided at a foot of the operator. The control means includes
The second regenerative force is changed according to the inclination angle of the accelerator lever,
The said 2nd regenerative force changes so that it may become large when the said inclination angle is large, and when the said inclination angle is small, it changes so that the said 2nd regenerative force may become small. Electric car.

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