WO2008092314A1

WO2008092314A1 - A balance system for disturbing moment

Info

Publication number: WO2008092314A1
Application number: PCT/CN2007/001665
Authority: WO
Inventors: Dehai Yu; Xiaochun Wang; Wenfeng Zhang; Chungang Cai; Junmin Zheng; Hongqi Chen; Qinghong Liu; Xi Pu
Original assignee: Dalian Guangyang Science & Technology Engineering Co., Ltd
Priority date: 2007-01-24
Filing date: 2007-05-22
Publication date: 2008-08-07

Abstract

A system used for balancing the disturbing moment in a swing-reciprocating device includes a mechanical device and a control system. The mechanical device comprises a connecting rod, a hydraulic system and a roller. In this mechanical device, the connecting rod joints with a piston rod of the hydraulic system at their ends. The other end of the connecting rod fixedly connects with a swing axle generating the disturbing moment. The joint center lies on a connecting line of a barycenter of the swing member generating the disturbing moment and a corresponding swing axle center. The roller is mounded at the bottom part of a hydraulic cylinder ofthe hydraulic system. A liquid inlet and a liquid outlet are provided at the bottom of the hydraulic cylinder. The control system is a constant pressure control unit that may adapt the disturbing moment caused by different weight of the workpieces. The present invention aims at the swing device generating the disturbing moment such as a biax rotating table and provides a system for balancing the disturbing moment, therefore improving the stability and reliability of the system, changing the conventional practice in which the disturbing moment is balanced by increasing the outputting torque of an electric motor, and having advantages such as saving use cost of the electric motor and so on.

Description

Subversion torque balancing system

The present invention relates to a mechanical device and a control system therefor, and more particularly to a mechanical device for balancing a subversive moment in a reciprocating oscillating mechanism and a control system therefor.

Background technique

There are devices for the swing mechanism, such as a two-axis turntable, also known as a two-coordinate rotary table, which generates a subversive moment during the reciprocating motion of the table. The reason, based on the mechanical analysis, can be concluded that the subversive moment is generated by the total gravity of the reciprocating oscillating mechanism of the biaxial turret and the workpiece clamped on the countertop, due to the center of gravity of the component that oscillates around the axis It does not coincide with the axis, so the center of gravity generates a gravitational moment with respect to the axis, which we call the subversive moment. As the swing angle changes, this subversive moment changes periodically. For example, the varying moment formed during the rotation of the two-axis turret. Referring to Fig. 1, it can be reflected that the subversive moment varies with the swing angle.

As shown in Figure 1, from the left to the right, the change in the subversive moment is Mc = 0 to M. = GX LX sin0 (Figure 1 shows the orthographic view of the end face of the two-axis turret shaft, G is the gravity of the oscillating member, L is the force of G relative to the axis of the oscillating axis, and Θ is the angle between the center of gravity and the vertical line of the axis , the counterclockwise direction is the positive direction of the angle, and the clockwise direction is the negative direction of the angle). As mentioned above, the subversive moment is substantially proportional to the sine of the corner.

The problem is that conventional devices that generate subversive moments usually do not have a mechanism to compensate for the subversive torque. Therefore, the subversive torque is completely carried by the drive motor during the movement of the turret. When selecting the motor, it is also necessary to increase the motor torque. To compensate for the adverse effects of the subversive torque, this will inevitably lead to unnecessary waste.

Summary of the invention

In view of the problems in the prior art described above, the present invention provides a mechanism for balancing the overturning moment, which aims to balance the subversive moment generated by the swinging mechanism, enhance the stability and reliability of the system, and change the tradition to increase the output torque of the motor. To solve the problem of subverting the torque problem, so as to achieve the purpose of reducing costs.

The technical solution of the present invention is implemented as follows:

A subversion torque balancing system characterized by including mechanical devices and control systems; correction page (Article 91) The mechanical device comprises a connecting rod, a hydraulic system and a roller, wherein the connecting rod and the piston rod of the hydraulic system are hinged at the end, and the other end of the connecting rod is fixedly connected with the swinging shaft generating the subversive moment, so it is necessary to ensure the same The center of gravity of the oscillating member that generates the subversive moment falls on the line connecting the hinge center and the corresponding oscillating axis; the bottom of the hydraulic cylinder of the hydraulic system is mounted with a roller to ensure the balance mechanism when the turret is tilted Follow-up; at the bottom of the hydraulic cylinder, there are inlet holes and outlet holes;

The control system is a constant voltage control unit. When the pressure in the hydraulic cylinder is constant, it is equivalent to a constant pressure F which is always vertically upward in one direction of the connecting rod. It can also be seen that when the oscillating member is swung to any corner, the moment of the constant pressure F of the piston rod acting on the connecting rod is actually FL'sine, wherein L' is the arm of the F-phase to the oscillating axis. When F = GL/L' is made, then FL'sin0 = GLsine, then the subversion torque of the turntable is balanced by the reverse torque FL'sine of the mechanism. i F=PS, where P is the pressure in the liquid/pneumatic cylinder, S is the piston bottom area, and S is constant, therefore, the pressure F in the holding cylinder is kept constant, that is, the internal pressure P is kept constant and the PSL' is satisfied. Under the condition of =GL, the balance mechanism balances the subversion torque of the turntable with the movement of the turntable.

In order to ensure a constant pressure in the hydraulic cylinder, a reasonable constant pressure control method must be adopted. The constant voltage control unit outputs the voltage through the CNC analog voltage, and the difference voltage is processed by the amplifier, and the current control proportional valve realizes the hydraulic control, and a pressure sensor is placed between the proportional valve and the hydraulic cylinder, thereby converting the actual pressure into The electrical signal is fed back to the PID regulator and compared with the CNC output analog voltage value. The difference between the two signals acts on the PID, and changes and outputs the command signal to the proportional valve.

The present invention has not been preceded by the prior art, and its advantages and beneficial effects are obvious compared with the conventional turntable:

(1) The rated torque of the selected drive motor is small, so the rated power of the motor will be smaller, which can save the cost of using the motor, reduce the power consumption, prolong the service life of the motor, and reduce the time and cost of maintenance. ;

(2) Enhance the stability and accuracy of such a swinging system that produces a subversive moment;

(3) In addition, since the rated power of the selected motor is small, the size of the motor is correspondingly reduced, which ultimately reduces the inertia of the machine tool.

DRAWINGS

8 of the drawings of the present invention, wherein

Figure 1 is a schematic diagram of the generation and change of the subversive moment;

Figure 2 is a schematic view of the mechanical device of the present invention;

3 to 7 are diagrams showing the state of use of the present invention at different swing angles; Figure 8 is a control diagram of the constant pressure unit of the present invention.

In the figure, 1, connecting rod 2, piston rod 3, hydraulic cylinder 4, inlet hole 5, liquid outlet 6, roller 7, swing shaft 8, swinging member.

detailed description

The two-axis rotary table, also known as the two-coordinate rotary table, is widely used in the machine tool industry, and the control of the two-axis rotary table must require numerical control to control the operation and positioning in order to achieve precision workpiece machining. During the reciprocating motion of the table, a subversive moment is generated. When the declination of the center of gravity from the vertical direction is θ (-95° < θ < +95°), the subversive moment generated is Me = GLsine. With the present invention, this subversive moment can be balanced to achieve the object of the present invention.

The mechanical device of the present invention is shown in Fig. 2. The mechanical device comprises a connecting rod, a hydraulic system and a roller, and is mounted on the two-axis rotary table, that is, the upper end of the connecting rod 1 is fixed on the double-axis rotary table which generates the subversive torque. On the rotating shaft, it can be fixed at one end of the rotating shaft, or can be sleeved on the shaft in a circular manner; at the same time, it is fixed by bolts or pins, and care should be taken to ensure the coaxiality. In the figure, the lower end of the connecting rod 1 is hinged on the piston rod 8 by a pin shaft, and the center of gravity of the two-axis turntable is generated to fall on the connecting line between the hinge center and the corresponding turntable axis, and is farther away from the axis than the center of gravity. . This is achieved by means of a positioning connection at the upper end of the connecting rod 1, such as the three-point positioning method of the preferred mode in Fig. 2.

The piston rod 2 drives the piston at the lower end, and the roller 6 is mounted on the bottom of the hydraulic cylinder 3 and placed on a plane parallel to the table. When the oscillating member that generates the subversive moment oscillates back and forth around the center of rotation of the oscillating shaft, the hydraulic cylinder reciprocates with the roller. Further, under the guiding action of the hydraulic cylinder 3, the piston reciprocates in the vertical direction. 3 to 7 are diagrams showing the state of use of the present invention at different swing angles.

At this point, as long as the bottom surface of the piston is subjected to a constant pressure F, and that FL' sin Θ = GLsin θ, that is, F GL / L, as shown in Figure 3. The subversion torque can be balanced to achieve the object of the present invention. Where L' is the force arm of F relative to the axis of oscillation, G is the gravitational force (predetermined) for generating the subversive moment, and L is the force arm of G relative to the axis of oscillation. For this purpose, a constant pressure unit is arranged on the underside of the piston. Of course, constant pressure is an ideal state, as long as the pressure can be basically changed in the mechanism.

There are various ways to implement a constant voltage unit in the prior art. As shown in FIG. 3 to FIG. 7, the volume of the lower part of the piston in the hydraulic cylinder 3 is filled with pressure oil; the bottom of the hydraulic cylinder 3 is provided with an oil inlet hole 4 and an oil outlet hole 5, and the two holes communicate with the hydraulic system. At this point, it is only necessary to ensure that the pressure of the hydraulic system is constant. The constant pressure control unit shown in Figure 8 is designed using classical control theory combined with modern industrial products. Through the CNC analog output, after the processing of the amplifier, the pressure of the hydraulic oil is controlled by the current control proportional valve, and a pressure sensor is placed between the proportional valve and the hydraulic cylinder, thereby converting the actual pressure into an electrical signal, that is, electricity. The pressure, feedback back to the PID is compared with the CNC output analog quantity. The difference between the two signals acts on the PID, and the command signal sent to the proportional valve is changed, so the proportional valve automatically controls the adjustment amount to eliminate the difference, thereby controlling the entire system. The pressure ensures that the pressure in the hydraulic cylinder is constant, thus balancing the subversive moment of the two-axis turret.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, and any technical person skilled in the art within the technical scope disclosed by the present invention, the technical solution according to the present invention Equivalent substitutions or modifications of the inventive concept are intended to be included within the scope of the invention.

Claims

Rights request

1. A balancing torque balancing system, characterized by comprising a mechanical device and a control system; said mechanical device comprising a connecting rod (1), a hydraulic system and a roller (6), wherein said connecting rod (1) The piston rod (2) of the hydraulic system is hinged at the end, and the other end of the connecting rod (1) is fixed to the swinging shaft (7) which generates the subversive moment, and the hinge center falls on the swinging member (8) which generates the subversive moment. The center of gravity is connected to the corresponding pivot axis; the hydraulic cylinder (3) of the hydraulic system is provided with a roller (6) at the bottom; at the bottom of the hydraulic cylinder, there is a liquid inlet (4) and a liquid outlet ( 5);

The control system is a constant voltage control unit.

2. The balance torque balancing system according to claim 1, wherein the constant voltage control unit outputs the voltage through the CNC, and the difference is processed by the amplifier and the signal, and the voltage is controlled by the current control proportional valve. A pressure sensor is placed between the valve and the hydraulic cylinder to convert the actual pressure into an electrical signal, which is fed back to the PID regulator and compared with the CNC output value. The difference between the two signals acts on the PID, changes and outputs the ratio. The command signal of the valve.

Correction page (Article 91)