JP2539457Y2 - Oil pump flow control device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for adjusting an oil discharge direction and an oil amount of an oil pump for supplying pressure oil to a hydraulic motor.

[0002]

2. Description of the Related Art A variable displacement pump is used as the oil pump, and the oil discharge direction and the flow rate of the pump can be adjusted as needed by rotating a tilt angle adjusting lever.

Conventionally, the tilt angle adjustment is performed indirectly via a hydraulic or pneumatic actuator in a large-size device, but generally, a push-pull (push-pull) is applied to a tilt angle adjustment lever. Many are done manually via rods or push-pull cables.

[0004] However, adjustments using push-pull rods and push-pull cables are primarily manual operations, and are structurally unsuitable for remote operations (remote control operations, wireless operations).

On the other hand, in an operation system using a hydraulic or pneumatic actuator, which is frequently used for automatic operation instead of manual operation, switching between forward rotation and reverse rotation can be freely performed, but fine adjustment on the forward rotation side is performed. Therefore, it is essential to provide a complicated control mechanism to avoid this.

[0006]

SUMMARY OF THE INVENTION The present invention overcomes the drawbacks of the conventional control device, has a simple structure, and can easily and automatically control the oil discharge direction and oil amount of the oil pump. It is intended to provide a flow control device.

[0007]

As a result of various studies, the present inventor has found that the tilt angle adjusting lever of the oil pump has a structure equivalent to a simple mechanism that is manually rotated, and that a simple deceleration is performed instead of the manual operation. If the motor is used as a drive source and the output shaft always rotates forward and backward within a predetermined angle via a limit switch operated by a cam fixed to the output shaft, the input to the motor can be controlled. The inventor has found that the required control is easily performed simply by opening and closing the switch, and based on this finding, came to the present invention.

That is, in the present invention, the tilt angle adjusting lever of the oil pump is connected via a connecting rod to an output lever connected to the output shaft of a drive mechanism that is rotated forward and backward at a low speed by a reversible motor with a speed reducer. Input circuit for forward / reverse rotation in the drive mechanism, two cam plates fixed to the output shaft, and output shafts arranged detachably around each cam plate to operate at the forward and reverse limit and neutral positions The present invention provides a flow control device for an oil pump, characterized in that four limit switches are provided and the input circuit is opened each time via the limit switches.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a front view showing the entire structure of the present invention, FIG. 2 is a side view showing a drive mechanism, FIG. 3 is a plan view showing an arrangement state of a cam plate and a limit switch, and FIG. FIG. 5 and FIG. 5 are explanatory diagrams showing the operation states of the cam plate and the limit switch by the signal current.

In FIG. 1, reference numeral 1 denotes a tilt angle adjusting lever of the oil pump. The left side of the figure from the vertical position is the normal rotation range, and the right side is the reverse rotation range.

Reference numeral 2 denotes an output lever, which is connected to the tilt angle adjusting lever 1 via a connecting rod 3. The output lever 2 is tilted by the left and right rotation of the output shaft 5 of the drive mechanism 4 to perform forward and reverse rotations within a range of 30 ° each from the vertical position to the left and right.

As shown in the side view of FIG. 2, the drive mechanism 4 is connected to the output shaft 5 which is rotated at a low speed through a forward / reverse rotation reduction motor having a reduction gear 7 built in a front surface of an electric motor 6. 2, two cam plates 8 and 9 of the same shape are fixed to the rear end (the left end in the figure) of the output shaft 5 and further surround these cam plates. As shown in the plan view of FIG. 3 and the rear view of FIG.
Has three limit switches LS1, LS2, LS3
However, one limit switch LS4 is located on the cam plate 9. That is, in FIG. 1, a limit switch LS1 which is switched by the cam plate 8 when the output shaft 5 rotates left by 30 ° is mounted, and a limit switch LS2 which is switched by this cam plate 8 when the output shaft 5 rotates right by 30 ° is mounted. Have been. A limit switch L that is switched by the cam plates 8 and 9 is located at an intermediate position between left and right and rotation.
S3 and LS4 are arranged and mounted. In FIG. 2, reference numeral 10 denotes a relay housing box, and 11 denotes a rear cover.

[0013]

The present invention has the above-described structure, and its operation sequence will be described with reference to FIG. 5, which is viewed from the same side as FIG. Since the motor rotates, the output shaft 5 rotates to the left (to the right in FIG. 4) and rotates to the normal rotation side. Therefore, the tilt angle adjusting lever 1 connected by the connecting rod 3 is pulled to increase the flow rate. Become.

Thus, at the position where the output shaft 5 is rotated by 30 °, the LS1 is switched by the cam plate 8 and the motor is stopped. In this case, since the motor rotates only when the SW1 signal is input, the output shaft 5 continues to rotate when the signal is input continuously, and the rotation angle of the output shaft 5 is changed in the forward rotation region. In the stopped state, the speed reduction ratio of the speed reducer is large, so that it is not easily returned by an external force and its position is maintained.

Next, when the motor is stopped,
Similarly, as shown in FIG. 5, when the signal of SW2 is input, the SW2 signal is output to the output shaft 5 rotated to the normal rotation side by the SW1 signal.
Rotate back. As a result, the tilt angle adjusting lever of the oil pump connected by the connecting rod is pushed back to reduce the flow rate. The rotation of the SW2 signal is continued when the signal is received similarly to the SW1 signal.
Is returned to the original position, it is stopped by the limit switch LS3 switched by the cam plate 8 rotating together with the output shaft 5. As described above, the output lever can be stopped and held at an arbitrary position in the normal rotation region by the signals of SW1 and SW2.

Next, when the signal of SW3 is input to the state stopped by the limit switch LS3 as shown in FIG. 5, the output lever 2 continues to rotate in the reverse direction by receiving the SW3 signal. At a right rotation of 30 ° (left rotation in the figure), the rotation is stopped by a limit switch LS2 which is switched by a cam plate 8 which rotates together with the output shaft 5. At the same time, the inclination angle adjusting lever 1 of the oil pump also rotates clockwise from the initial position, so that the direction of oil suction and discharge of the oil pump changes and the flow rate increases. If the SW3 signal is continuously supplied even after the rotation is stopped by the limit switch LS2, the output shaft 5 is stationary at the stopped position.
By turning off the three signals, the electric motor rotates in the forward direction by the relay provided in the circuit. And the output shaft 5
Returns to the initial position, it is stopped by the limit switch LS4 switched by the cam plate 9 of the output shaft 5.

As described above, the SW3 increases the angle in the reverse rotation area by receiving the signal, and automatically returns the output shaft 5 to the original position by cutting off the signal. As a result, the direction of the suction and discharge of the oil pump is switched with that of the normal rotation side, and the flow rate also increases. However, when the SW3 signal is cut off, the flow rate decreases and the oil pump does not discharge in any direction. Further, even when the output shaft 5 is rotated and held in the normal rotation region, the output shaft 5 returns to the initial position direction by receiving the SW3 signal. That is, SW2
Acts the same as. However, if the SW3 signal is further applied, the output shaft 5 passes through the initial position and enters the reverse rotation region to perform the above-described operation. Similarly, the tilt angle adjusting lever of the oil pump performs an operation corresponding to the output shaft 5 of the reversible motor. Thus, all operations are performed on SW1, S
This is performed by the signals of W2 and SW3.

As described above, the present invention employs SW1, SW2,
Since the rotation of the predetermined angle is automatically performed only by inputting the signal of SW3, the structure is simple.

[0019]

According to the present invention, the concrete pumping amount can be adjusted by applying the present invention to a hydraulic circuit of a concrete pump truck. That is, by controlling all signals of SW1, SW2, and SW3 by remote control using a remote controller or the like, the oil discharge direction and flow rate of the oil pump are controlled at a position away from the concrete pump car main body to adjust the concrete pumping amount. Can be. In addition, in the event of blockage of the pumping pipe during concrete pumping, a reverse rotation process is immediately performed by sending the reverse rotation signal SW3, and the apparatus returns to the neutral position and stops all discharge work. Measures can be taken.

[Brief description of the drawings]

FIG. 1 is an overall front view.

FIG. 2 is a side view of a driving mechanism.

FIG. 3 is a plan view of a limit switch portion.

FIG. 4 is a rear view of the drive mechanism.

FIG. 5 is an explanatory diagram showing an operation order by a signal current.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tilt angle adjustment lever 2 output lever 3 connecting rod 4 drive mechanism 5 output shaft 6 motor 7 reduction gear 8, 9 cam plate LS1, LS2, LS3, LS4 limit switch SW1, SW2, SW3 signal current

Claims (1)

(57) [Scope of request for utility model registration] 1. A tilt angle adjusting lever of an oil pump is connected via a connecting rod to an output lever connected to an output shaft of a drive mechanism which is rotated forward and backward at a low speed by a reversible motor with a speed reducer. An input circuit for reverse rotation, two cam plates fixed to the output shaft, and four output shafts which are detachably arranged around each cam plate and which operate at the forward rotation limit position, the reverse rotation limit position and the neutral position, respectively. With each limit switch attached,
An oil pump flow control device wherein an input circuit is opened each time via these limit switches.