KR960007420B1 - Control apparatus of hydraulic power steering for a vehicle - Google Patents

Abstract

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Description

Control device of hydraulic power steering device in industrial vehicle

1 is a circuit diagram showing one embodiment of a power steering motor of a hydraulic power steering device and a control device of the present invention related thereto.

2 is a flowchart showing an example of a processing procedure executed in the control apparatus of the present invention.

3 is a flowchart showing another example of a processing procedure executed in the control apparatus of the present invention.

4 is a circuit diagram schematically showing a control device of a power steering motor in a conventional general hydraulic power steering device.

5 is a circuit diagram schematically showing another example of the conventional control apparatus.

FIG. 6 is a flowchart showing a conventional processing procedure executed in the control device of FIG.

* Explanation of symbols for main parts of the drawings

1: power steering motor 2: battery

3: power steering contactor 4: relay coil

5: direction switch 6: unloading controller

7: microcomputer 8: contactor drive circuit

13: vehicle speed sensor

[Industrial use]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact hydraulic power steering device in an industrial vehicle such as a battery type fork lift, and more particularly, to an apparatus for preventing power waste by stopping a power steering motor for driving a hydraulic pump during a stop.

[Prior art]

In industrial vehicles such as battery type forklifts, it is common to use a power steering motor (hereinafter referred to as a motor) in a hydraulic power steering device to drive a hydraulic pump as a hydraulic source. The motor continues to run even in the stopped state, consumes power, and the noise of the motor causes noise.

For this reason, conventionally, as shown in FIG. 4, a power steering contactor 3 (hereinafter referred to as a contactor) is provided between the motor 1 and the battery 2, and the relay of the contactor 3 is provided. The coil 4 is directly controlled by the direction switch 5, and the motor 1 is stopped at the time of stopping. The direction switch 5 is constituted by a forward switch 5F and a reverse switch 5R. When the direction lever (not shown) is tilted forward, the forward switch 5F is inserted and tilted backward. In one case, the reverse switch 5R is input, and in the neutral state, both switches 5F and 5R are opened. In the conventional configuration shown, since the direction switch 5 is connected in series with the relay coil 4 of the contactor 3, the relay coil 4 is excited when the switch 5F or 5R is turned on in the forward and backward directions. The protector 3 is closed, as a result of which the motor 1 is driven so that the power steering device functions. On the other hand, when stopping and returning the direction switch 5 to neutral, the relay coil 4 is not excited, the contactor 3 is opened, and the motor 1 stops.

However, in the configuration of FIG. 4, when the forward and backward changes relatively slowly, the contactor 3 is opened and closed at that time, so that the operation sound is noisy and there is a problem such as deterioration of the contact. In addition, when the direction switch 5 is made neutral in the middle of a path and descends by inertia, the motor 1 is stopped and the effect of reducing steering wheel steering force by the power steering device cannot be obtained.

Therefore, since the direction switch 5 is conventionally connected to the microcomputer 7 of the traveling and unloading controller 6, the contactor 3 can be computer controlled to solve the above problem by using this. (See Figure 5). 6 shows the processing sequence.

First, when any of the switches 5F and 5R is inserted in the forward / backward direction of the direction switch 5, the timer is reset, and a drive command is issued to the contactor drive circuit 8. Thereby, the relay coil 4 is excited, the contactor 3 closes, and the motor 1 drives.

Next, when the direction switch 5 is returned to the neutral state, it is checked whether or not the timer is operating, and if not, the timer is started. If the operation time does not reach the set time even though the timer is in operation, the contactor driving circuit 8 continues to excite the relay coil 4 of the contactor 3, so that the power steering is maintained in an effective state. Therefore, even if the direction switch 5 is inserted again, the contactor 3 remains closed, and thus there is no useless opening and closing operation. In addition, even in the case of inertia running on the aforementioned hill road, the steering wheel can be lightly steered. When the operation time of the timer becomes longer than the set time, a stop command is sent to the contactor driving circuit 8, whereby the contactor 3 is opened and the motor 1 is stopped.

In the conventional control method using such a microcomputer, the setting time of the timer is set to a long time of several tens of seconds or more in response to inertia driving. For this reason, when the loading switch is lowered with the key switch 9 immediately after returning the direction switch 5 to neutral or when the loading operation is performed while the vehicle is stopped, the motor 1 stops driving for a set number of seconds or more. As a result, there was a problem such as wasting power and noise of the motor.

[Problems to Solve Invention]

Therefore, the problem to be solved by the present invention is to prevent the contactor from opening and closing even when the direction switch is changed relatively slowly, and to enable the power steering device even when the path is lowered by inertia in a neutral state. And stopping the motor quickly in the stopped state.

[Means for solving the problem]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and a control apparatus for opening and closing control of a steering contactor connected to a power steering motor for driving a hydraulic pump of a hydraulic power steering device in an industrial vehicle by whether the direction switch is in neutral or not. The vehicle speed sensor is connected, and the vehicle speed sensor takes in the vehicle speed information to determine whether the vehicle is in a driving state or a stationary state. When the vehicle is in the driving state, the contactor is closed to drive the motor, and the vehicle is stopped for a predetermined time. In the case of the present invention, the contactor is opened to stop the motor.

[Action]

In the related art, whether or not the vehicle is stopped is determined by the information in the direction switch, but in the present invention, the vehicle speed information is used to determine it. Therefore, in the present invention, the stationary state and the running state can be distinguished reliably. This makes it possible to operate the power steering device even during inertia driving. In addition, it is possible to set the motor driving time when the direction switch is neutral without considering inertia, but to consider only the conversion operation of the direction switch, so that it can be set in a short time.

EXAMPLE

EMBODIMENT OF THE INVENTION Hereinafter, although preferred embodiment of this invention is described in detail according to drawing, in the figure, the same code | symbol is used for the same or equivalent part of said conventional structure.

FIG. 1 shows a power steering motor 1 and a control device according to the present invention related to the hydraulic power steering device of a battery type forklift, the configuration of which is almost the same as the conventional configuration shown in FIG. In the figure, 1 is a motor, 2 is a battery, 3 is a contactor, 4 is a relay coil of the contactor 3, 5 is a direction switch, 6 is a travel unloading controller, and 9 is a key switch. The travel and unloading controller 6 is an interface for digitizing and inputting the information from the forward switch 5F and the reverse switch 5R of the microcomputer 7, the stabilization power supply 10 and the direction switch 5, respectively. (11), the contactor drive circuit 8 for controlling the excitation of the relay coil 4 by the command signal from the microcomputer 7, and the main circuit 12 for driving the unloading motor circuit and the unloading motor circuit. have. Although not particularly illustrated, the microcomputer 7 is composed of an input / output unit, arithmetic processing unit, and a storage unit.

In the present invention, the vehicle speed sensor 13 is connected to the input of the microcomputer 7 in the travel unloading controller 6 via the F / V conversion circuit 14. The vehicle speed sensor B is provided in a vehicle stand for speed display, and by using this, a significant design change can be eliminated.

As described above, in the present invention, the drive command to the contactor drive circuit 8 in the case of the microcomputer 7 in the travel and unloading controller 6 in a certain case by the information from the direction switch 5 and the vehicle speed sensor 13. Alternatively, a stop command is issued. Although various processes are considered as the processing procedure, one example will be described according to the flowchart of FIG.

First, the microcomputer 7 judges whether or not at the step (S _1), direction switch 5 is in neutral. If it is not neutral, that is, if the forward or reverse switches 5F and 5R of the direction switch 5 are closed, the timer is reset (step S2), and the drive command is sent to the contactor drive circuit 8. (Step S3). As a result, the relay coil 4 is excited to close the contactor 3, the motor 1 is driven to drive the hydraulic pump, and power steering is possible. Then, the process of step S1, step S2, and step S3 is repeated, until the direction switch 5 returns to neutral, and the motor 1 continues to drive.

On the other hand, when the direction switch 5 is in neutral, the process advances from step S1 to step S4 to determine whether or not the timer is in operation. If the timer is not operating, it is determined in step S5 whether the vehicle speed is zero or not, that is, whether the vehicle is stopped or running, based on the information in the vehicle speed sensor 13. When the vehicle speed is not zero and in the running state, the routines of steps S1, S4, and S5 are repeated, and the driving state of the motor 1 is maintained. Therefore, in the case of descending the hill while driving, power steering is not effective even when the inertia travels with the direction switch 5 being neutral.

The vehicle speed is zero, stopped, and the timer is started as step S6. Thereafter, the process returns to the start, and since the timer is operating, the process proceeds from step S4 to step S7. In step S7, it is determined whether or not the timer operation time is equal to or greater than the preset time stored in advance in the storage unit of the microcomputer 7. If it is within the set time, the routines of step S1, step S4 and step S7 are repeated. If more than the set time, the routine moves to step S8 to issue a stop command to the contactor drive circuit 8. Then, the excitation of the relay coil 4 is released, the contactor 3 is opened, and the driving of the motor 1 is stopped. In this case, since the contactor 3 is in the closed state within the set time, the operation sound of the contactor 3 does not occur even if the direction switch 5 is changed. Therefore, the set time is good as a few seconds that can correspond to the relatively slow forward and backward conversion, and the vehicle can be set to stop the motor 1 in a few seconds because the vehicle stops. It is not necessary to consider that the driving of the motor 1 is controlled as the information in the vehicle speed sensor 13 at the time of coasting.

In the above processing procedure, when the motor vehicle 1 stops on the path, and the motor 1 is stopped and the oscillation of the path is performed without the direction switch 5 being put in and descends by the inertia, the contact 3 is opened in step S1, The routines of steps S4 and S5 are repeated and power steering becomes ineffective. However, in the case of oscillating uphill, the direction switch 5 is normally operated even when the drive is inertia. Therefore, even if the processing procedure shown in FIG. However, if the advantages are set in the order of processing shown in Fig. 3, the solution can be solved.

The processing procedure of FIG. 3 is a point where step S11 for determining the presence or absence of the vehicle speed is located after step S10 for determining the state of the direction switch 5, and is different from that of FIG. In this case, when the direction switch 5 is not neutral, as in the second case, the timer is reset (step S12) and the driving command is issued to the contactor drive circuit 8 (step S13). Even if (5) is neutral and the vehicle speed is not zero due to inertia driving or the like, the process shifts from step S12 to step S13. As a result, even when the direction switch 5 oscillates in the neutral state after the vehicle stops, it is determined that the vehicle is traveling on the vehicle speed information, and a driving command is issued to the contactor driving circuit 8, and the motor 1 drives. The power steering device is made to function.

If the vehicle stops and the vehicle speed becomes zero, it is judged whether or not the timer is in operation (step 14). In the case of denial, the timer is started in step S15. 10), the routines of step S11, step 14 and step S16 are repeated. When the operation time of the timer becomes longer than the set time, the flow advances to step S17 to issue a stop command to the contact drive circuit 8 to stop the motor 1.

Although the embodiment of the present invention has been described in accordance with the state of the driving operation of the forklift above, it will be understood that the processing of FIGS. 2 and 3 is caused by changing the path appropriately during the actual driving operation.

In the above embodiment, the microcomputer 7 in the existing travel and unloading controller 6 is used as the control device of the present invention. However, the present invention is not limited thereto, and a dedicated microcomputer or an electronic circuit may be used.

As described above, according to the present invention, even when the direction switch is returned to the neutral on the hill road and lowered from the inertia, the power steering device is operated to reduce the steering wheel steering force.

In addition, in the case of a relatively slow direction switch switching operation, the contactor is kept in the closed state, and there is no annoying opening and closing operation sound, and the deterioration of the contact can be prevented by reducing the contact count of the contact.

Since the stop state can be reliably determined by the vehicle speed sensor, the motor can be stopped after a few seconds after stopping. Therefore, conventionally, the electric power wasted as a motor during the loading and unloading operation in the stationary state is saved, premature consumption of the battery can be prevented, and noise caused by the motor sound can also be suppressed.

Claims (1)

In the control apparatus of the hydraulic power steering apparatus which controls opening / closing of the steering contactor connected to the power steering motor for driving the hydraulic pump of the hydraulic power steering apparatus in an industrial vehicle by the direction switch being neutral or not, the vehicle speed sensor 13 Means for determining whether the vehicle is in a driving state or a stationary state by receiving vehicle speed information through the F / A conversion circuit, and closing the power steering contactor 3 in the driving state. And a microcomputer (7) which stops the power steering motor (1) by opening the power steering contactor (3) when the vehicle is stopped for a predetermined time. Control device.