JP3807495B2 - Motion setting method of electric servo press - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slide motion setting method for an electric servo press that controls a servo motor to control a slide position, and in particular, the rotational power of a servo motor is converted into a linear movement by a power conversion mechanism, and the linear movement is converted into a link mechanism. The present invention relates to a motion setting method of an electric servo press that converts to a slide up / down movement.
[0002]
[Prior art]
Conventionally, as an electric servo press that controls the slide position by controlling the servo motor, the rotary power of the servo motor is converted into a linear movement in the vertical direction by a ball screw or the like, and the slide is directly driven up and down by this vertical power. Is well known. In this servo press, the rotation angle of the servo motor and the slide position are in a proportional relationship. For example, the slide position is fed back as the motor rotation angle, and the rotation angle and speed of the servo motor are controlled, so that the slide position can be accurately detected. And its speed can be controlled.
[0003]
In order to perform molding with such a servo press, it is necessary to set a slide motion (hereinafter simply referred to as motion) that defines the position and speed of the slide in accordance with the material of the workpiece, the type of processing, and the like. As a conventional motion setting method for this purpose, when setting a motion similar to a link motion (motion of a mechanical link press), for example, it is set so that the slide position is controlled by a multistage motion as shown in FIG. There is something that is. This multi-stage motion divides the desired slide stroke into a desired number of different speed areas (for example, a high-speed descent area, a low-speed descent area, a machining area, a low-speed rise area, a high-speed rise area, etc.) In addition, the slide start position, end position, slide speed, slide stop time (including stop selection), and the like are previously set by the operator in the controller. The controller confirms that there is no contradiction between these setting data (such as whether the slide start position and end position between adjacent areas match or the set slide speed does not exceed the maximum motor output speed). If the consistency is not abnormal, the slide position and speed are controlled based on the setting data.
[0004]
[Problems to be solved by the invention]
By the way, as one of the slide drive mechanisms of the electric servo press, the rotational power of the servo motor is converted into a substantially horizontal linear movement by a predetermined power transmission mechanism, and this horizontal linear movement is moved up and down the slide via the link mechanism. Something that has been converted to mobile is being developed in recent years. This link mechanism makes it easy to obtain a large pressing force, and the processing load during pressurization is not directly transmitted to the power transmission mechanism of the motor shaft, so that the durability of the power transmission mechanism and the like can be improved.
[0005]
However, when the conventional motion setting method as described above is applied to the electric servo press via the link mechanism, there are the following problems.
(1) When setting a multistage motion, the number of setting data and the number of setting operations are very large, and the data setting operation is troublesome. For example, it is necessary to input data such as the number of area steps of multi-step motion, upper limit position, lower limit position, slide stroke length, maximum motor speed, and slide start position, end position, slide speed, slide stop time of each area. is there.
[0006]
(2) Since the rotational power of the servo motor is converted into the vertical movement of the slide via the linear movement converter and the link mechanism, the relationship between the motor rotational speed and the slide speed is not always constant, and the slide position It changes according to. That is, even if the motor rotational speed is constant, the slide ascending / descending speed is high near the slide upper limit position and low near the slide lower limit position. Therefore, when the multistage motion is set, the motor rotation speed required to achieve the slide speed set in the predetermined area corresponding to the slide position in the area is equal to or less than the set motor use speed maximum value. Need to be. However, it is very difficult for an operator who inputs data to set data with consistency so that there is no contradiction while considering such setting conditions, and this takes time for setting. There is a problem that work efficiency decreases.
[0007]
The present invention has been made paying attention to the above-mentioned problems, and it is possible to easily set motion in an electric servo press that converts a substantially horizontal linear motion power into a vertical slide movement via a link mechanism. The object is to provide a motion setting method for an electric servo press.
[0008]
[Means, actions and effects for solving the problems]
  In order to achieve the above object, according to a first aspect of the present invention, a forward / reverse rotational motion of a servo motor is converted into a substantially horizontal linear motion by a power conversion mechanism, and this linear motion is lifted and lowered by a link mechanism. In the motion setting method to set the slide motion of the electric servo press that converts to the motion, the stroke length of the slideServo motor maximum rotation speedA first step of setting the stroke length, a second step of automatically determining the number of division steps of the stroke length according to the set stroke length, and the determined number of division steps of the set stroke length And a third step of setting the divided slide positions as the start position and end position of each stage area,Based on a predetermined relational expression between the slide position P and the motor rotation angle θ in each step area by the power conversion mechanism and the link mechanism, with each slide speed in each step area being constant, A fourth step of automatically setting the maximum slide speed in the area of each step so that the maximum value is substantially equal to the set maximum motor use speed;The method has
[0009]
  According to the first invention, the slide stroke lengthAnd the maximum rotation speed of the servo motorIs input automatically according to the input stroke length, and a multi-stage motion in which the input stroke length is divided at a predetermined slide position is automatically set based on the input step length. Therefore, the number of operations for data input at the time of motion setting is reduced, and operability can be greatly improved.Furthermore, since the maximum slide speed within each stage area is automatically set for the automatically set motion, it is possible to set a motion that allows efficient production. In addition, since the operator does not have to set the slide speed while considering the relationship between the motor rotation speed and the slide speed in each area, the motion setting becomes very easy.
[0010]
  According to the second aspect of the present invention, the slide motion of the electric servo press that converts the forward / reverse rotational motion of the servo motor into a substantially horizontal linear motion by the power conversion mechanism and converts the linear motion into the slide up / down motion via the link mechanism. In the motion setting method to be set, according to the first step of setting the stroke length of the slide and the maximum rotation speed of the servo motor, and according to the set stroke length and the maximum rotation speed of the motor, the stroke length A second step of automatically determining the number of division steps, and dividing the set stroke length at a predetermined slide position by the determined number of division steps, and using the divided slide positions as the start position and the end of the area of each step A third step to set as a position;Based on a predetermined relational expression between the slide position P and the motor rotation angle θ in each step area by the power conversion mechanism and the link mechanism, with each slide speed in each step area being constant, A fourth step of automatically setting the maximum slide speed in the area of each step so that the maximum value is substantially equal to the set maximum motor use speed;The method has
[0011]
  According to the second aspect of the invention, only by inputting the slide stroke length and the maximum servo motor speed, the number of division stages is automatically determined according to the input stroke length and the maximum servo motor speed. A multi-stage motion is automatically set by dividing the input stroke length at a predetermined slide position based on the number of stages. Therefore, the number of operations for data input at the time of motion setting is reduced, and operability can be greatly improved.Furthermore, since the maximum slide speed within each stage area is automatically set for the automatically set motion, it is possible to set a motion that allows efficient production. In addition, since the operator does not have to set the slide speed while considering the relationship between the motor rotation speed and the slide speed in each area, the motion setting becomes very easy.
[0012]
  The third invention is the1 or2 In the invention,The default setting value of the maximum number of rotations of the servo motor is the maximum number of rotations that can be used by the servo motor.It's a way.
[0013]
  According to the third invention,The maximum slide speed in each area is set so that the maximum value of the motor speed when converted to the motor shaft is approximately equal to the maximum available speed of the servo motor. This means that the motor capacity is fully utilized, and it is very easy for the operator to set up motion with increased production efficiency.It becomes.
[0014]
  The fourth invention is the1, 2 orIn the third invention, the slide speed in the area of each step can be set by an override ratio with respect to the maximum slide speed.
[0015]
According to the fourth aspect of the invention, the operator sets the slide speed in the area of each step by the override ratio with respect to the maximum slide speed, so that the motor rotation speed in terms of the motor shaft is equal to or higher than the set motor rotation speed. The correct slide speed is not set by mistake, the motion can be set reliably without considering the consistency of each data, and the operability at the time of setting is good.
[0016]
  The fifth invention is the first, second, third or fourth invention,in frontThe method has a fifth step in which the slide stop in each step area can be set.
[0017]
According to the fifth aspect, since it is possible to set the slide stop in each step area, various multi-step motions can be set according to the processing conditions, and it is possible to deal with various workpieces in general.
[0018]
According to a sixth invention, in the first or second invention, after the first step, an upper limit position and a lower limit position of the stroke are automatically set based on the set stroke length of the slide, and from the upper limit position, The method includes a sixth step of automatically setting a soft limit that is a movement limit of the slide at a position that is a predetermined distance above and a position that is a predetermined distance below the lower limit position.
[0019]
According to the sixth aspect of the invention, since the soft limit that becomes the movement limit is automatically set outside the range of the upper limit position to the lower limit position, the runaway of the slide can be prevented in advance.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an electric servo press to which the present invention is applied. In the figure, the slide 9 and the plunger 6 of the electric servo press 1 are both supported by the main body frame 2 so as to be movable up and down, and the slide 9 and the plunger 6 are connected at the lower part of the plunger 6. The upper portion of the plunger 6 is connected to the main body frame 2 via a link mechanism 3 including a first link 5a, a triaxial link 4, a second link 5b, and the like. That is, the first link 5a is rotatably connected by the pin between the upper part of the main body frame 2 and one end of one side of the triaxial link 4. Further, a second link 5b is rotatably connected by a pin between the other side of both ends of the one side of the triaxial link 4 and the upper portion of the plunger 6.
[0023]
The pinion 13 attached to the output shaft of the servo motor 15 for slide drive meshes with the gear 12. A shaft member 11 a is fixed to the shaft center of the gear 12, and the shaft member 11 a rotates around the main body frame 2. It is supported freely. Further, a male screw is engraved on a part of the outer peripheral surface of the shaft member 11a, and a nut member 11b is screwed into the male screw so as to be movable in the axial direction, and the bracket 11c on which the nut member 11b is fixed. Is movable together with a nut member 11b along a guide (not shown), and the tip end portion of the bracket 11c is rotatably connected to the remaining one end portion of the triaxial link 4 of the link mechanism 3 by a pin 14. The shaft member 11a, the nut member 11b, and the bracket 11c constitute a power conversion mechanism 11 that converts the rotational power of the servo motor 15 into linear power.
[0024]
An angle sensor 16 including an encoder for detecting a motor rotation angle is attached to the motor shaft of the servo motor 15. The motor rotation angle signal Sθ of the angle sensor 16 is input to the servo amplifier 17, and the servo amplifier 17 sets a deviation value between the motor speed command Cv from the controller 20 and the motor rotation speed obtained from the motor rotation angle signal Sθ. Based on this, the motor power command Cm is output to the servo motor 15.
[0025]
In addition, a slide position detection for detecting the ascending / descending position of the slide 9 constituted by a non-contact type sensor such as a linear sensor is provided between the slide 9 and the upright 7 erected at the corner of the main body frame 2. A vessel 8 is attached. Here, the sensor body 8a of the linear sensor has an elongated shape in the vertical direction, and one end portion is attached to the other end side of the bracket 7a attached to the upright 7. One scale portion 8b is attached to the sensor body 8a. Is attached to the slide 9 along a vertical direction at a predetermined minute distance. The position detection signal Sp of the slide position detector 8 is input to the controller 20, and the controller 20 determines the motor speed command Cv based on the position deviation value between the slide position along the preset motion and the position detection signal Sp. And the obtained motor speed command Cv is output to the servo amplifier 17.
[0026]
The operation of the slide 9 of the electric servo press 1 configured as described above will be described. When the servo motor 15 is rotated, the shaft member 11a is rotated through the pinion 13 and the gear 12, whereby the nut member 11b moves forward and backward in the axial direction together with the bracket 11c, and the triaxial link 4 is pushed and pulled in the direction of the arrow. To do. The nut member 11b is reciprocally driven so that the triaxial link 4 moves between a position 4b corresponding to the slide upper limit position indicated by the two-dot chain line and a position 4c corresponding to the slide lower limit position indicated by the solid line. Thereby, the plunger 6 and the slide 9 are reciprocated between the upper limit position and the lower limit position via the second link 5b connected to the upper part of the plunger 6.
[0027]
As described above, the rotational power of the servo motor 15 is converted into a substantially horizontal driving force by the ball screw mechanism, and this driving force is converted into the vertical driving power of the slide 9 via the link mechanism 3. Therefore, the relationship between the motor rotation angle θ (which is proportional to the moving position of the nut member 11b) and the slide position P is not linear, and is represented by a well-known sine function as shown in FIG. Become. For example, in order to control the slide speed (ΔP / Δt) at a predetermined constant value in a predetermined area, the motor rotational speed (Δθ / Δt) is set according to the above-mentioned relational expression according to the slide position P. It means that it must be controlled to change based on. Furthermore, for example, in order to obtain a motion substantially similar to the motion of a conventional mechanical link press (hereinafter referred to as a link motion), it is necessary to smoothly change the slide speed. The motor rotation speed must be controlled to change smoothly according to the change.
[0028]
Therefore, in the present invention, the motion is set by multi-stage motion as shown in FIG. 3, for example. That is, in the slide lowering step, the slide stroke length (range from the slide upper limit position to the lower limit position) necessary for actual machining is divided into a plurality of speed areas A1 to An (n = 4 in FIG. 3), and each speed area A1. In ˜An, the slide speed is controlled to a predetermined value (constant). Further, in the present embodiment, an example in which the slide ascending process is provided with one stage, that is, one speed area is shown, but the present invention is not limited to this. Then, the position at which the position of the second link 5b becomes the bottom dead center (the lowest lowered position) is fixed as the lower limit position so that the pressing force at the lower limit position becomes the maximum value of the capability of the machine itself. The motion is always determined based on the position.
[0029]
Next, a data input procedure for motion setting will be described with reference to FIG. FIG. 4 is a screen display of a data setting device (not shown) provided in the controller 20. This data setting device has a graphic display such as a liquid crystal display or a plasma display, and the motion setting data can be viewed on the same screen.
(1) First, the operator selects a motion setting mode using a mode setting unit (not shown). As a result, the data setting device is switched to a screen (hereinafter referred to as a stroke setting screen) on which a stroke can be set. The mode setting unit may use, for example, the data setting device configured by a programmable display with a touch panel, or may use a changeover switch such as a rotary switch.
(2) Next, the operator inputs a desired stroke length on the stroke setting screen.
[0030]
(3) Then, the controller 20 displays a multi-stage motion setting screen having a predetermined number of stages according to the input stroke length on the data setting device. The number of steps is determined in advance according to the input stroke length as described above so that the multi-step motion is accurately approximated to a smooth link motion, and for the same reason, The stroke start position, end position, and maximum slide speed are determined in advance according to the input stroke length. For example, FIG. 4 shows a four-stage multistage motion setting screen. The number of steps indicates the number of steps when the slide 9 descends from the upper limit position to the lower limit position. Then, on the multi-stage motion setting screen, the controller 20 uses the input stroke for the stroke start position, end position, and slide speed (this is a possible speed within the set value of the motor rotation speed described later) in each stage area. Predetermined values corresponding to the length are displayed, and default data are displayed for the motor speed, the upper limit stop time, the speed override and stop time for each stage area. As each default data, the motor rotation speed is the maximum usable rotation speed of the servo motor 15, and the upper limit stop time is a predetermined minute time tu (0.05 seconds in the drawing). The time is set to 100% and 0.00 seconds, respectively. These default data can be changed by the operator (that is, can be arbitrarily set). FIG. 4 shows data that can be changed by a thick line frame.
[0031]
(4) Next, the operator sets the motor rotation speed, the upper limit stop time, the speed override and stop time of each stage area to the desired values so as to meet the processing conditions such as the workpiece forming type, material, and plate thickness. Change the data to However, the motor speed is the desired maximum motor speed at the time of machining, and is not more than the maximum usable speed, the upper limit stop time is not less than the default predetermined minute time tu, and the speed override of each stage area is not more than 100%. The stop time is 0 seconds or longer.
[0032]
Here, the motion setting method of the controller 20 according to the data input procedure will be described in detail with reference to FIGS.
(1) First, the number of steps is determined in accordance with the input stroke length, and when the motion of the input stroke length is divided into the number of steps, it is divided into each area A so as to be close to a smooth link motion. Determine the slide position and its slide speed. In an example of four stages as shown in FIG. 3, the slide speed (that is, the gradient of motion) at the divided slide positions P1, P2, P3 and the areas A1, A2, A3, A4 is determined. The lower limit position Pd is set to the above-described reference position (corresponding to the bottom dead center of the link mechanism), and the upper limit position Pu is set to a position above the lower limit position Pd by the input stroke length. Then, the upper limit position Pu, each divided slide position Pn, and the lower limit position Pd are sequentially set as the start position and end position of each area as shown in FIG. At this time, the maximum speed of the motor rotation speed when converted into the motor shaft based on the predetermined relational expression between the slide position P and the motor rotation angle θ as shown in FIG. It is determined so as to be approximately equal to the maximum usable rotational speed of the motor 15, that is, so that the capacity of the servo motor 15 can be used to the maximum. The slide speed thus obtained is set as the default data.
[0033]
(2) When the motor rotation speed is changed to a value smaller than the default value of 100%, the controller 20 converts the slide speed in each area to the motor shaft in the same manner as described above, and the motor rotation speed in each area. Is re-determined to a smaller value so that the maximum value becomes substantially equal to the motor speed after the change. In this case, if the number of steps is the default number of steps and only the slide speed is made smaller, the upper range in the same area, that is, the vicinity of the start position is actually lower than the lower range, that is, the vicinity of the end position. Since the motor rotation speed at the time of control is slow, the time to use at a low motor rotation speed becomes long. Therefore, the capacity of the servo motor 15 is not used to the maximum, and the work efficiency is lowered. For this reason, when the motor rotation speed is set to be small, it is desirable to automatically set the number of stages to be further increased according to the value.
[0034]
(3) When the speed override of the predetermined area is changed to a value smaller than the default value 100%, the controller 20 slides the data obtained by multiplying the calculated slide speed value of the area by the speed override value after the change. Use the speed setting value. Thereby, the maximum value of the motor speed at the time of control in the corresponding area becomes a value smaller than the set motor speed.
(4) When the stop time of the predetermined area is changed, the controller 20 sets the changed value as the stop time set value. At the time of control in actual machining, when reaching the end position of each area, control is performed to wait at that position for the stop time set value.
[0035]
In this embodiment, the pinion 13 is engaged with the gear 12 in order to transmit the rotational power of the servo motor 15 to the ball screw mechanism. However, the present invention is not limited to this structure. For example, a belt is wound between two pulleys. You may make it the structure which transmits and transmits.
[0036]
Below, the effect by this invention is demonstrated.
By simply inputting the slide stroke length, the number of steps of the multi-step motion is automatically determined according to the stroke length, and accordingly, the maximum motor rotation number at the time of use (in FIG. 4, simply expressed as the motor rotation number). Since the slide start position, end position and slide speed data of each area are automatically set and machining control can be executed as it is, the operability at the time of motion setting can be improved. Further, since the default setting value of the motor rotational speed at this time is the maximum usable rotational speed of the servo motor, the slide can be efficiently driven at high speed by using the motor capacity to the maximum.
Further, when the operator changes the default value of the automatically set motor rotation speed, the division stage number is determined again according to the changed motor rotation speed, and the motor rotation speed in each stage area is a predetermined value. Since it does not drop below, it is possible to set a highly productive motion.
[0037]
Furthermore, the default value of the slide speed in each area is the motor rotation speed in each area when converted into the motor shaft based on the relational expression between the slide position P by the power transmission mechanism and the link mechanism and the motor rotation angle θ. Since the maximum slide speed is set such that the maximum value is substantially equal to the set motor speed, it is possible to set an efficient motion using the motor capacity to the maximum, thereby improving productivity.
Further, since the slide speed of each area can be changed by the override ratio of the default value to the maximum slide speed, the operator can relate the slide position P by the power transmission mechanism and the link mechanism to the motor rotation angle θ. Since it can be set without considering the formula, operability at the time of motion setting is good.
[0038]
In addition, one start position and the other end position of adjacent areas are matched, and the maximum value of the motor rotation number obtained by converting the slide speed of each area into the motor shaft is equal to or less than the set motor rotation number. Thus, a consistency check such as setting a limit on the set value of the slide speed of each area is automatically performed according to the slide position of each area and the set motor speed. As a result, even in an electric servo press in which the relationship between the slide position P and the motor rotation angle θ is non-linear, the operator can easily set the motion without considering the above-mentioned consistency, so the operability at the time of setting is extremely high. Good for.
[0039]
In addition, the motor rotation speed, upper limit stop time, slide speed and stop time of each area can be changed to the operator's desired values, so you can set motion that suits the processing conditions such as workpiece processing type, material, plate thickness, Various types of workpieces can be used in general, and machining accuracy can be secured.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an electric servo press to which the present invention is applied.
FIG. 2 is an explanatory diagram of a relationship between a motor rotation speed and a slide position according to the present invention.
FIG. 3 is an explanatory diagram of multi-stage motion.
FIG. 4 is a display example of a data setting screen according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electric servo press, 2 ... Main body frame, 3 ... Link mechanism, 4 ... Triaxial link, 5a ... 1st link, 5b ... 2nd link, 6 ... Plunger, 8 ... Slide position detector, 9 ... Slide, 11 DESCRIPTION OF SYMBOLS ... Power conversion mechanism, 11a ... Shaft member, 11b ... Nut member, 11c ... Bracket, 12 ... Gear, 13 ... Pinion, 14 ... Locking pin, 15 ... Servo motor, 16 ... Angle sensor, 17 ... Servo amplifier, 20 ... controller.

Claims (6)

The forward / reverse rotational motion of the servo motor (15) is converted into a substantially horizontal linear motion by the power conversion mechanism (11), and this linear motion is converted to the vertical motion of the slide (9) via the link mechanism (3). In the motion setting method to set the slide motion of the electric servo press,
A first step of setting the stroke length of the slide (9) and the maximum rotation speed of the servo motor (15) ;
A second step of automatically determining the number of divisions of the stroke length according to the set stroke length;
A third step of dividing the set stroke length at a predetermined slide position by the determined number of division steps, and setting the divided slide positions as start positions and end positions of the areas of the respective stages ;
Predetermined relationship between the slide position (P) and motor rotation angle (θ) in each step area by the power conversion mechanism (11) and the link mechanism (3), with each slide speed in each step area being constant. And a fourth step of automatically setting the maximum slide speed in the area of each stage so that the maximum value of the motor rotation speed is substantially equal to the set maximum motor use rotation speed based on the equation The motion setting method of the electric servo press characterized by the above-mentioned. The forward / reverse rotational motion of the servo motor (15) is converted into a substantially horizontal linear motion by the power conversion mechanism (11), and this linear motion is converted to the vertical motion of the slide (9) via the link mechanism (3). In the motion setting method to set the slide motion of the electric servo press,
A first step of setting the stroke length of the slide (9) and the maximum rotation speed of the servo motor (15);
A second step of automatically determining the number of divisions of the stroke length according to the set stroke length and the motor maximum rotation speed;
A third step of dividing the set stroke length at a predetermined slide position by the determined number of division steps, and setting the divided slide positions as start positions and end positions of the areas of the respective stages ;
Predetermined relationship between the slide position (P) and motor rotation angle (θ) in each step area by the power conversion mechanism (11) and the link mechanism (3), with each slide speed in each step area being constant. And a fourth step of automatically setting the maximum slide speed in the area of each stage so that the maximum value of the motor rotation speed is substantially equal to the set maximum motor use rotation speed based on the equation The motion setting method of the electric servo press characterized by the above-mentioned. In the motion setting method of the electric servo press according to claim 1 or 2,
A motion setting method for an electric servo press, characterized in that a default setting value of the maximum rotation speed of the servo motor (15) is set to a maximum rotation speed that can be used by the servo motor (15) . In the motion setting method of the electric servo press according to claim 1, 2, or 3,
A method for setting a motion of an electric servo press, characterized in that a slide speed in each step area can be set by an override ratio with respect to the maximum slide speed. In the motion setting method of the electric servo press according to claim 1, 2, 3, or 4,
Motion setting method of the electric servo press, characterized in that it comprises a pre-Symbol fifth step that can be set to slide stopping areas of each stage. In the motion setting method of the electric servo press according to claim 1 or 2,
After the first step, the upper limit position and the lower limit position of the stroke are automatically set on the basis of the set stroke length of the slide (9), and the upper limit position is separated from the upper limit position by a predetermined distance. A method for setting a motion of an electric servo press, comprising: a sixth step of automatically setting a soft limit that is a movement limit of the slide (9) at a position spaced apart from the lower limit position by a predetermined distance.

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