JPH04203506A - Controller for hydraulic motor - Google Patents

Abstract

PURPOSE:To finely operate a hydraulic motor with precise so as to enhance operating efficiency by disposing a variable flow rate control valve in a circuit from a switch valve to a tank, and inputting signals indicative of a position of the switch valve and an engine speed of the hydraulic motor into a controller so as to vary and adjust a throttle amount of the variable flow rate control valve. CONSTITUTION:There is provided a variable flow rate control valve 15 in a circuit from a switch valve 14 to a tank 13. Detection signals are input from a position sensor 21 provided in connection with the switch valve 14 and a speed sensor 23 attached to a hydraulic motor 11 into a controller 22. The controller 22 drives a solenoid 18 on the basis of the signals of the sensors 21, 23, to thus change and adjust a throttle of the variable flow rate control valve 15 through an operating rod 16 of a hydraulic cylinder device 17. Therefore, the hydraulic motor 11 can be finely operated with ease and precise, thereby enhancing operating efficiency and safety.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hydraulic motor control device, for example, a hydraulic motor control device used in hydraulic construction machinery such as a hydraulic truck crane and a hydraulic cidabell. Concerning what is effective when used.

[Conventional technology]

In construction machinery such as truck cranes, boom rotation and winch drive are performed by hydraulic motors. In addition, as a means for controlling the drive of this hydraulic motor, a directional switching valve such as a manual type or a hydraulic pilot L electric control type is used, and the lane operator can control the direction and speed by operating this switching valve. , the force is adjusted.

That is, the hydraulic fluid sent from the hydraulic pump is sent to the directional control valve. When the operation position of the switching valve is at the neutral position, the rotation of the hydraulic motor is stopped. When the operating position is the normal position, the hydraulic motor rotates in the normal direction. When the hydraulic motor is driven by a boom, it rotates to the right, for example, and when it is a winch, it operates, for example, to the right. Conversely, when the operating position of the switching valve is in the opposite position, the hydraulic motor rotates in the opposite direction. If the drive function of the hydraulic motor is to turn the boom, it will rotate to the left, and if it is a winch, it will lower the boom.

[Problem to be solved by the invention]

Hydraulic construction machinery is widely used for various cargo handling and civil engineering work, but in recent years there has been an increasing demand for fine movement operation due to larger construction machinery and work in narrow spaces for urban development. This includes building work by extending a long boom with a large crane, and positioning work such as aligning bolt holes between reinforcing bars. This type of work requires high positioning accuracy, so the crane operator must perform precise positioning by turning, winching, etc. Then, it is necessary to match the instructions of the sling operator, who is the other operator of the crane operation. If the cooperation between the crane operator and the rigging worker does not go well, it will not only reduce work efficiency but also cause safety issues for the rigging worker who is at a high place, and damage to equipment. . In addition, in construction machinery, the control operation position of the switching valve to obtain slow rotation with the same hydraulic motor is not necessarily the same position depending on the rotational change of the hydraulic pump caused by the engine and the load condition. In other words, in Fig. 2, Conventionally, the opening area from the P port of the switching pulp to the C boat was the largest opening area with respect to the spool stroke, as shown by the shaded area, so in order to obtain the pressure to operate the crane motor, the same pump was required. Even if the flow rate is different, the spool stroke position must be changed depending on the load at the time in order to obtain the rotational speed depending on the crane load.

During such a series of operations, the crane operator is particularly required to concentrate and perform fine movements. Moreover, if this work is repeated, it will cause considerable fatigue.
These problems have been raised for some time, and have gradually been resolved through efforts to improve switching valves and hydraulic motors.

However, on the other hand, due to reasons such as a generational change in crane operators and a shortage of workers in response to the increasing number of construction machines, the number of crane operators has come to include people who are not completely thorough in W. For these reasons, there are many users who are not satisfied with the conventional level of improvement, and the demand for improved fine control operability is increasing year by year.

The present invention has been made in view of these problems, and an object of the present invention is to provide a wi control device for a hydraulic motor that can simplify fine movement control operations of the hydraulic motor.

[Means to solve the problem]

A hydraulic motor control device according to the present invention includes a hydraulic motor;
In a hydraulic motor control device configured such that the operation of the hydraulic motor is controlled by a switching valve interposed between a hydraulic power source and a tank connected to the hydraulic motor, the switching valve is in a normal position. A variable flow rate control valve is interposed in the hydraulic circuit through which the pump discharge flow exits from the switching valve and leads to the tank, and the variable flow rate control valve is configured to change and adjust its throttle amount by a controller, Further, the switching valve is provided with a position sensor that detects the amount of operation thereof, and this position sensor is configured to transmit the detected data to the controller, and further, the rotation speed of the hydraulic motor is A rotation sensor for detection is provided, and the rotation sensor is configured to send its detection data to the controller, and the controller adjusts the throttle amount of the variable flow rate control valve based on the detection data of the position sensor. Along with changing and adjusting the
The present invention is characterized in that the fine movement of the hydraulic motor is maintained constant by changing and adjusting the throttle position of the variable flow rate control valve based on the detection data of the rotation sensor.

[Effect]

According to the above-mentioned means, for example, when the crane operator operates the switching valve to the fine movement operation region, the position sensor automatically detects the operation state. Based on this detection, the controller controls the variable flow rate control valve, and also automatically controls the output rotation of the hydraulic motor to be constant by feedback control based on this control and the detection result of the rotation sensor. This automatic control frees the crane operator from the highly difficult fine movement operations.

〔Example〕

FIG. 1 is a circuit diagram showing a hydraulic motor control device according to an embodiment of the present invention, and FIGS. 2 and 3 are diagrams for explaining its operation.

In this example, the mII of the hydraulic motor according to the present invention is
at is the turntable of the boom in the crane equipment (
The hydraulic motor is configured to control a hydraulic motor for driving the rotation of the motor (not shown).

The hydraulic motor 11 to be controlled is connected to a hydraulic pressure 11i12 and a tank 13 via a switching valve 14, and the switching valve 14 is configured as a 3-position, 6-boat, manually operated spool switching valve. A variable flow rate control valve 15 is connected to the C boat of the switching valve (hereinafter referred to as spool valve) 14, and the variable flow rate control valve 15 is connected to the tank 13 on the other side. The operation $116 for changing the throttle amount of the variable flow rate control valve 15 is configured to be driven by a hydraulic cylinder device 17, and a hydraulic power source 12 is connected to this hydraulic cylinder device 17 via a solenoid valve 18. is connected. The solenoid valve 18 changes and adjusts the throttle amount of the variable flow rate control valve 15 by controlling the stroke of the hydraulic cylinder device 117 via the operating rod 16.

On the other hand, a position sensor 2 is attached to the spool 20 of the spool valve 14.
1 is provided, and the position sensor 21 is configured to detect the stroke amount of the spool 20. This position sensor 21 is connected to a controller 22 equipped with a microcomputer, etc., and is adapted to transmit its detection data to the controller 22. On the other hand, a rotation sensor 23 is disposed on the hydraulic motor 11, and the rotation sensor 23 is configured to detect rotation of the hydraulic motor 11. This rotation sensor 23 is connected to the controller 22 and transmits its detection data to the controller 22. controller 22
The electromagnetic valve 18 is connected to the output side of the controller 22, and the controller 22 is configured to perform the functions described below.

Next, the action will be explained.

When the boom turntable (not shown) is rotated in the forward direction by the hydraulic motor 11, the spool valve 14 is switched from the neutral position to the forward switching position by the crane operator. At this time, as shown in FIG. 2, when the spool 2o is operated beyond the stroke range S of the fine movement operation area, which will be described later, the C boat and the D boat in the spool valve 14 are completely closed, and the P boat is completely closed. The A boat and the B port and the T boat will be fully opened.

As a result, a large amount of hydraulic oil flows from the hydraulic source 12 to the hydraulic motor 11 via the spool valve 14, so that the hydraulic motor 1
1 is rotated in the forward direction, and the turntable is turned in the forward direction.

Conversely, when the boom turntable is swiveled in the opposite direction by the hydraulic motor 11, the spool valve 14 is switched from the neutral position to the reverse switching position 1 by the crane operator.

As a result, a large amount of hydraulic oil flows in the opposite direction to the above, as follows: hydraulic pressure 1112 → P port of spool valve 14 → B boat → hydraulic motor 11 → A boat of spool valve 14 → T boat → tank 13. The motor 11 is rotated in the opposite direction, and the turntable is rotated in the opposite direction.

By the way, while the turntable is being slightly moved, the spool 20 of the spool valve 14 is slowly operated very slightly by the crane operator.

Now, the slight movement of the turntable when the spool 20 of the spool valve 14 is slowly and slightly operated in the forward direction will be described.

When the spool 20 is operated in the forward direction, the position sensor 21
The stroke is detected by When the stroke of the spool 20 reaches the stroke range S of the fine movement operation area shown in FIG. 2 and stays in that stroke range S for a predetermined time (for example, 0.5 seconds), the controller 22 An operation command signal for rotating the hydraulic motor 11 is derived based on a table such as the one shown in FIG.

Here, FIG. 3 shows the stroke amount in the stroke range S of the fine movement operation area of the spool valve 14 and the stroke amount of the hydraulic motor 1.
1 is a diagram showing the relationship between rotational speed and rotational speed, and is obtained by an empirical method such as an experiment using the hydraulic motor control device according to the above configuration or a computer simulation using its design data. It is data. Data corresponding to this diagram is stored in the controller 22 as a table. The controller 22 compares the stroke amount input from the position sensor 21 with this table and sets the rotation speed of the hydraulic motor 11 to be controlled.
The stroke amount input from the summer sensor 21 is SI,
In this case, the rotational speed of the hydraulic motor 11 is set to NI.

Then, the controller 22 controls the set hydraulic motor 11.
The variable flow control valve 15 necessary to obtain the rotational speed N,
The aperture amount is determined by comparing it with a preset table (not shown). This table can also be obtained using the empirical method described above.

Subsequently, the controller 22 outputs an operation control signal for the hydraulic cylinder 17 to obtain the obtained throttle amount and transmits it to the electromagnetic valve 18 .

The solenoid valve 18 operates the hydraulic cylinder device 17 based on a command signal from the controller 22 in accordance with the command. By operating this hydraulic cylinder device 17, the variable flow rate control valve 15 is throttled by a predetermined amount via the operating rod 16.

When the variable flow control valve 15 is throttled, the C of the spool valve 14
Since the pressure in the boat increases, the pressure in the A or B boat of the spool valve 14 that is in the middle of switching increases more than usual. This increase in pressure at the A or B port of the spool valve 14 causes the hydraulic motor 11 to rotate at a low speed (for example, about 5 rpm) specified by the controller 22, so the turntable is moved very slightly. It turns out.

On the other hand, when the hydraulic motor 11 is rotated at a low speed, its rotational speed (number of rotations) is detected by the rotation sensor 23, and the detected data is transmitted to the controller 22. The controller 22 compares this detected actual rotation speed with the target value (rotation speed) Nl set corresponding to the stroke amount SI of the spool 20, as described above, and sets the actual rotation speed to the target value. A feedback control signal necessary to maintain the value is determined, and the control signal is fed back to the solenoid valve 18.

Then, this feedback control signal causes the solenoid valve 18 to
The rotational speed of the hydraulic motor 11 is maintained constant by operating the hydraulic cylinder device 17 and adjusting the throttle amount of the variable flow rate control valve 15. In this way, by maintaining the rotation of the hydraulic motor 11 at a constant low speed, the turntable is slowly and slightly moved.

According to this embodiment, the crane operator slightly moves the spool 20 of the spool valve 14, without changing the operating position of the spool 20 as in the conventional case, in order to obtain the same slow rotation according to changes in the rotation of the hydraulic pump and load conditions. Since the turntable can be moved slowly and slightly by simply operating within the stroke range of the operation area, the turntable can be easily and precisely moved.

Therefore, crane work can be performed accurately and safely.

Note that the present invention is not limited to the above embodiments,
It goes without saying that various changes can be made without departing from the gist of the invention.

For example, as an operating means for operating a variable flow control valve,
In addition to using a combination of a hydraulic nolinder device and a TM valve, an electromagnetic plunger device or the like may also be used. In the above embodiment, control of a hydraulic motor used to drive a turntable of a crane was explained. ,
The present invention is not limited to this, but also includes a hydraulic motor used for raising a crane boom or rotating a winch.
It can be used in all control devices for hydraulic motors used in various construction machines, machine tools, etc.

〔Effect of the invention〕

As explained above, according to the present invention, by simply operating the spool of the spool valve to the stroke range of the fine movement operation region, the second
Since the spool opening area within the shaded area in the figure is automatically adjusted, the hydraulic motor can be easily and precisely moved in small movements. Moreover, this can be useful for increasing efficiency, improving safety, and reducing crane operator fatigue in construction machine work.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a hydraulic motor control device according to an embodiment of the present invention, and FIGS. 2 and 3 are diagrams for explaining its operation. 11... Hydraulic motor, 12... Hydraulic source, 13...
Tank, 14...Switching valve, 15...Variable flow control valve, 16...Operation rod, 17...Hydraulic cylinder device, 1
8... Solenoid valve, 20... Spool, 21... Position sensor number, 22... Controller, 23... Rotation sensor, S... Stroke range of fine movement operation area. Agent Patent Attorney Tatsuya Kajihara Figure 1 Sufu Ayusu 1o-7 Figure 3 S+ - School Straw 7

Claims (1)

[Claims] 1. A hydraulic motor configured such that the operation of the hydraulic motor is controlled by a switching valve interposed between the hydraulic motor and a hydraulic power source and tank connected thereto. In the control device, a variable flow rate control valve is interposed in a hydraulic circuit through which a pump discharge flow at a normal position of the switching valve exits from the switching valve and communicates with the tank, and the variable flow rate control valve is controlled by a controller to control its throttle amount. The switching valve is configured to be changed and adjusted, and the switching valve is provided with a position sensor that detects the amount of operation thereof, and this position sensor is configured to transmit the detected data to the controller. Further, a rotation sensor for detecting the rotation speed of the hydraulic motor is provided, and the rotation sensor is configured to transmit its detection data to the controller, and the controller is configured to detect the rotation speed of the position sensor. In addition to changing and adjusting the throttle amount of the variable flow control valve based on the detected data,
A control device for a hydraulic motor, characterized in that the control device for a hydraulic motor is configured to maintain a constant slight movement of the hydraulic motor by changing and adjusting the throttle amount of the variable flow rate control valve based on the detection data of the rotation sensor.