JPH05319232A - Braking mechanism for vehicle - Google Patents

Abstract

PURPOSE:To attain a stop in an optimum position after stopping a running DC motor by detecting a drive current just before stopping driving of the running DC motor, and changing a time from stopping the running DC motor to applying an electromagnetic parking brake by the detected current. CONSTITUTION:An electromagnetic parking brake 19 is a negative type electromagnetic brake, to apply a brake to a brake plate by a brake spring normally in the case of not feeding a current from wire harness. A current flowing in a running DC motor 15 is always detected by a current detecting part 20, to shorten a time of applying the electromagnetic parking brake after stopping the running DC motor 15 particularly in the case of high current value such as ascending road and in the case of low current value such as descending road and low rotational speed of the motor 15, and to lengthen a time of applying the brake after stopping the running DC motor 15 in the case of operation such as on a flat road except the above-mentioned case. By turning on a forward/reverse switch, after releasing the electromagnetic parking brake 19, the motor 15 is driven after a time delay.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking mechanism for a vehicle which uses a traveling DC motor as a drive source and brakes an electromagnetic parking brake as soon as the rotation of the traveling DC motor is stopped to prevent coasting. ..

[0002]

2. Description of the Related Art Conventionally, a technique relating to a self-propelled vehicle for sloping ground equipped with an automatic braking device has been publicly known. For example, it is like the technique described in Japanese Patent Laid-Open No. 50-103031.

[0003]

DISCLOSURE OF THE INVENTION The present invention is a DC for traveling.
The motor is used as a drive source, and the traveling DC motor is rotating during traveling, so coasting is not performed, but once the aircraft stops, the traveling DC motor has no braking force and rotates freely. When the vehicle stops, the aircraft naturally moves. Therefore, in order to eliminate this problem, the parking brake constituted by the negative electromagnetic brake is braked at the same time when the traveling DC motor is stopped. In this case, after the traveling DC motor 15 is stopped, if the driving DC motor 15 is too fast, the traveling DC motor 15 is suddenly stopped, so that the load becomes large, and if the driving DC motor 15 is too slow, the vehicle loses the slope and travels naturally. The timing of applying the electromagnetic parking brake 19 is optimized.

[0004]

The problems to be solved by the present invention are as described above, and the means for solving the problems will be described below. That is, in a vehicle that uses the traveling DC motor 15 as a drive source and is provided with the electromagnetic parking brake 19 and brakes the electromagnetic parking brake when the traveling DC motor 15 is stopped, the drive current immediately before the driving DC motor 15 is stopped is changed. The time from when the traveling DC motor 15 is stopped to when the electromagnetic parking brake 19 is braked is changed based on the detected current, and the braking start time is shortened on a downhill with a small drive current. Even on the uphill
This is a quick braking time.

[0005]

[Operation] Next, the operation will be described. Although the present invention is configured as a crawler type traveling device, it is not limited to this. Then, the crawler type traveling device includes a traveling DC motor 1
The rotation from 5 is driven via the drive mission device M. In the case of normal driving by the engine, when the rotation is stopped, it is necessary to compress the air in the cylinder by the piston in order to rotate the engine from the outside. Therefore, when it is not decompressed, it works as a braking force. ..
However, in the case of the traveling DC motor 15, when it stops, the braking force does not act, so when it stops on a sloping ground, it naturally starts moving to the lower side. An electromagnetic parking brake 19 is provided in order to prevent this natural descent. When the electromagnetic parking brake 19 is stopped while the traveling DC motor 15 is inertially rotating, the load becomes large, and after a lapse of time after the stop, the electromagnetic parking brake 19 naturally descends on a slope. The present invention uses this timing as the current detection unit 20
It is controlled by the current detected by.

[0006]

EXAMPLES Next, examples will be described. 1 is an overall front view of an aerial work vehicle constructed by the vehicle of the present invention, FIG. 2 is an overall side view of the aerial work vehicle, and FIG. 3 is an enlarged side view of an operation box K and a joystick controller 4. Four
Is also an enlarged plan view of the operation box K and the joystick controller 4, FIG. 5 is a side view of only the joystick controller 4, FIG. 6 is a plan view of only the joystick controller 4, and FIG. 7 is an operation direction and operation of the joystick controller 4. A plan view showing the state,
8 is a flow chart drawing of the steering control mechanism of the crawler type traveling apparatus of the present invention, FIG. 9 is a side view of the electromagnetic parking brake 19, FIG. 10 is a rear sectional view of the electromagnetic parking brake 19, and FIG.
1 is a drawing showing the relationship between the current of the current detector 20 and the braking start time, and FIG. 12 is a drawing showing another embodiment.

1 and 2, the crawler type traveling device 1 is shown.
The overall configuration of an aerial work vehicle equipped with will be described. The crawler type traveling device 1 is driven after the traveling DC motor 15 is driven by the battery 17 and the rotational force of the traveling DC motor 15 is changed by the drive mission device M.
A side clutch actuator 18R and a side clutch actuator 1 are provided in the drive mission device M.
8L is arranged to connect and disconnect the side clutch in the drive mission device M. The side clutch actuators 18L and 18R are each composed of an electric motor.

A controller 14 is arranged near the traveling DC motor 15. A scissors link mechanism S is interposed between a traveling frame 2 that is moved by the crawler type traveling device 1 and a workbench Y. The scissors link mechanism S is composed of a total of 6 links configured in 3 stages. The upper and lower lifting cylinders 12 and the lower lifting and lowering cylinders 13 expand and contract. An operation box K is arranged on the workbench Y, and a joystick controller 4 is arranged on the operation surface of the operation box K.

Next, the operation box K will be described with reference to FIGS. 3 and 4. The operation box K is provided on the locking plate 8 protruding from the handrail vertical rod 7 provided on the workbench Y,
By fitting the fitting locking plate 9 protruding from the side,
It is removable. Since the locking plate 8 and the workbench Y are arranged at a plurality of positions inside, the position of the operation box K can be adjusted. When the operation box K is moved, the operation box K may be placed on the floor.
Is taken out from the side. On the operation surface of the operation box K, the joystick controller 4 and the lifting lever 5
Is mainly arranged, and an erroneous operation guide bar 6 is arranged around the erroneous operation in order to prevent erroneous operation of the lever.

Next, the configuration of the joystick controller 4 will be described with reference to FIGS. 5 and 6. The joystick controller 4 is rotatable in the front-rear and left-right directions by 360 degrees, and is composed of a speed operation angle potentiometer 36 attached to the side surface and a steering operation angle potentiometer 35 attached to the front surface. And as shown in FIG.
The forward / backward tilt of the joystick controller 4 is detected by the speed operation angle potentiometer 36, and various controls are performed. Until the joystick controller 4 tilts from the upright position by a certain small angle,
A "running stop zone T" is provided, and the running DC motor 15 is configured to start forward and reverse rotation only when tilted further. Then, both forward and backward, a speed command is issued in proportion to the tilt angle of the joystick controller 4, and by the microcomputer program function,
Speed control is performed by PWM driving the driving DC motor 15.

The PWM drive control system is a Pulse Width Mo
It is a control mechanism called dulation. That is, when a signal associated with the tilt angle of the joystick controller 4 is used as an input signal, the width of the carrier pulse is analog-modulated according to the amplitude of the input signal, and the traveling DC motor 15 is driven by the analog-modulated carrier pulse. That is, the number of revolutions is changed.

Then, when tilted over a certain angle,
“Full-voltage application zone without PWM drive” in which PWM drive is not performed any more is provided on both the forward drive side and the reverse drive side. Further, in the zone where the steering operation angle potentiometer 35 detects the turning angle of the joystick controller 4 in the left-right direction and the side-clutch is not disengaged immediately in the zone tilted by a slight left-right angle, the "side-clutch left-right entrance zone Q". Is provided. When tilted further, the vehicle enters the "side clutch left-off zone" and the "side clutch right-off zone", and the side clutch actuator 18L and the side clutch actuator 18R are operated to perform the steering operation. In the present invention, the "side clutch left / right entrance zone Q" is larger than the "travel stop zone T".

In FIG. 7, a position outside the "side clutch left / right entering zone" and outside the "travel stop zone",
That is, in the A, B, C, D, E, F, G, and H zones, either the left or right side clutch is connected or disconnected. Next, in the zone from A to H, in the zone in which the joystick controller 4 is largely tilted in the left, right direction of B, C, F, G, the operation requiring a sharp turn or a sharp turn is required, so the joystick controller 4 Based on the signal of the speed operation angle potentiometer 36 which changes by tilting back and forth, the PWM drive control is performed to drive DC
The speed of the motor 15 is changed as desired.

Next, in A to H, the joystick controller 4 has a small turning angle to the left and right, and in the A, D, E, and H zones where high speed steering is desired, the joystick is used. The tilt angle in the front-rear direction of the controller 4 and the tilt angle in the left-right direction are compared, and the signal of the larger tilt angle of the steering operation angle potentiometer 35 and the speed operation angle potentiometer 36 is used to determine the forward or reverse speed. decide.

In FIG. 8, all the operation parts operated by the joystick controller 4 are disclosed. The tilt angle of the joystick controller 4 is transmitted to the controller 14. The controller 14 makes a comparison and determination, and the pulse signal for PWM drive control is converted into an analog signal to control the rotational direction and the rotational speed of the traveling DC motor 15. Further, the current detection unit 20 detects the current required to drive the traveling DC motor 15, controls the electromagnetic parking brake 19, and further controls the side clutch actuator 18L and the side clutch actuator 18R.

The construction of the negative electromagnetic brake will be described with reference to FIGS. 9 and 10. Wire harness 1
A control current flows through 9c to excite the solenoid 19b. The electromagnetic parking brake 19 is a negative type electromagnetic brake, and normally, when current is not sent from the wire harness 19c, the braking plate 1 is operated by the braking spring 19d.
The braking is applied to 9e. When the traveling DC motor 15 is rotated, the solenoid 19b is excited by the current supplied to the traveling DC motor 15, the braking plate 19e is released, and the traveling DC motor 1
It is possible to rotate 5 times.

Even in the event of a power failure, the braking plate 19e
Is provided with a manual release lever 19a for enabling the release. In the configuration of the electromagnetic parking brake 19, as shown in FIG. 11, the current flowing through the traveling DC motor 15 is constantly detected by the current detecting unit 20, and especially when the current value is high, such as when climbing uphill, and when the current value is downhill. When the current value is low, such as when the slope or the number of rotations of the motor is low, when the electromagnetic parking brake is braked for a short time after the driving DC motor 15 is stopped and the vehicle is driven in a flat place other than that. Means that the time for applying the braking after the driving DC motor 15 is stopped is lengthened.

Next, in FIG. 12, when the operator turns on the forward switch and the reverse switch, the electromagnetic parking brake 19 is released at the same time, and after a time delay, the traveling DC motor 15 starts rotating. Configured to do so. And the forward / reverse switch is O
At the same time as FF, the traveling DC motor 15 is stopped,
After a time delay, the electromagnetic parking brake 1
9 is configured to brake. Further, the time delay can be controlled to be large or small by the tilt angle of the machine body detected by the tilt sensor.

[0019]

Since the present invention is configured as described above, it has the following effects. That is, in the vehicle driven by the traveling DC motor 15, when the rotation of the traveling DC motor 15 is stopped, the braking force does not act, so that the vehicle may naturally descend in the case of a sloping ground. An electromagnetic parking brake 19 is provided in order to prevent this. However, if the inertial rotation of the traveling DC motor 15 does not stop in the case of a flat ground, braking will be performed.
The load will be heavy. In addition, in the case of an uphill road, the vehicle moves backward when braking is delayed. In case of downhill,
It will proceed to a position different from the scheduled stop location.

In the present invention, by changing the braking timing of the electromagnetic parking brake 19 according to the state of the ground, it becomes possible to stop the traveling DC motor 15 at the optimum position after stopping. is there.

[Brief description of drawings]

FIG. 1 is a front view of an aerial work vehicle configured by a steering vehicle of the present invention.

FIG. 2 is an overall side view of an aerial work vehicle equipped with the crawler type traveling device of the present invention.

FIG. 3 is an enlarged side view of a portion of an operation box K and a joystick controller 4.

FIG. 4 is an enlarged plan view of the operation box K and the joystick controller 4.

FIG. 5 is a side view of only the joystick controller 4.

FIG. 6 is a plan view of the 7-joystick controller 4 only.

FIG. 7 is a plan view showing an operation direction and an operation state of the joystick controller 4.

FIG. 8 is a flowchart of a steering control mechanism of the crawler type traveling device according to the present invention.

9 is a side view of the electromagnetic parking brake 19. FIG.

FIG. 10 is a rear sectional view of the electromagnetic parking brake 19.

FIG. 11 is a diagram showing the relationship between the current of the current detector 20 and the braking start time.

FIG. 12 is a view showing another embodiment.

[Explanation of symbols]

 B Operation Box T Travel Stop Zone Q Side Clutch Left / Right Input Zone 1 Crawler Type Traveling Device 2 Travel Frame 4 Joystick Controller 18L, 18R Side Clutch Actuator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masafumi Tsujita 428 Enami, Okayama City Seirei Industrial Co., Ltd. In-house

Claims (1)

[Claims] 1. A vehicle in which a traveling DC motor 15 is used as a drive source, an electromagnetic parking brake 19 is provided, and the electromagnetic DC parking brake is stopped and the electromagnetic parking brake is braked immediately before the driving DC motor 15 is stopped. The drive current is detected, and the time from when the traveling DC motor 15 is stopped to when the electromagnetic parking brake 19 is braked is changed by the detected current, and the braking start time is shortened on a downhill with a small drive current. A vehicle braking mechanism characterized by shortening the braking time even on an uphill road with a large drive current.