JP4573051B2 - Cylinder device drive control method - Google Patents

Description

  The present invention relates to a drive control method for a cylinder device, and more particularly, to a drive control method for a cylinder device capable of displacing a piston of the cylinder device under pressure fluid and a drive action of a drive unit.

  Conventionally, for example, by attaching a workpiece to the end of a piston rod disposed in a cylinder, supplying pressure fluid to the cylinder chamber of the cylinder, and displacing the piston rod under the pressing action of the pressure fluid A cylinder device that conveys the workpiece and positions it at a target position is used.

  When displacing a workpiece with this cylinder device, the output is large because a pressure fluid is used, and a workpiece with a large load can be displaced. However, since the pressure fluid is a compressible fluid, the workpiece can be moved with high accuracy. It was difficult to position.

  On the other hand, a work is attached to a ball screw provided in the cylinder device, and the work is displaced by rotating the ball screw by a rotation drive source (for example, a motor). There is known a method for accurately positioning the target with respect to the target position.

  And the cylinder apparatus which combines the driving force at the time of displacing the workpiece | work by the pressure fluid mentioned above and the positioning accuracy of the said workpiece | work under the drive effect | action of a rotational drive source is proposed (for example, refer patent document 1).

Japanese Patent Laid-Open No. 9-210141

  By the way, in the prior art according to Patent Document 1, when the cylinder device is driven or stopped, the load on the cylinder device may fluctuate due to a change in the weight of the workpiece. In this case, it is conceivable to change the driving force of the piston by increasing / decreasing the supply amount of the pressure fluid of the cylinder device in response to the load fluctuation of the workpiece, but the supply amount is instantly corresponding to the load fluctuation. It is difficult to increase or decrease. For this reason, it is possible to obtain a driving force corresponding to the load fluctuation by immediately increasing or decreasing the driving torque of the rotary driving source by electrical control.

  However, in this case, since it is necessary to provide a rotary drive source having a large drive torque in advance in order to cope with load fluctuations occurring in the cylinder device, the rotary drive source is increased in size and cost is increased. There is a problem of end.

  Further, during normal driving in which load fluctuation does not occur in the cylinder device, a large rotational drive source is not necessary, so that there is a problem that excessive power is consumed by always driving the large rotational drive source.

  On the other hand, in recent years, there is a demand for downsizing the cylinder device because of the space for installing the cylinder device.

  The present invention has been made in consideration of the above-mentioned various problems, and when load fluctuations on the cylinder occur, the load on the drive unit is reduced to perform workpiece positioning control with high accuracy, and the entire apparatus. It is an object of the present invention to provide a drive control method for a cylinder device that can reduce the size, labor-saving, and manufacturing cost.

In order to achieve the above-mentioned object, the present invention provides a cylinder apparatus comprising: a piston movably provided on a cylinder body; a ball screw that engages with the piston; and a drive unit that rotationally drives the ball screw. Driving the cylinder device that moves the work attached to the piston by displacing the piston by at least one of the pressure of the pressure fluid supplied to the cylinder chamber of the cylinder body and the driving force of the driving unit A control method,
Displacing the piston along the cylinder body via the ball screw under the driving action of the driving unit;
Before the weight load applied to the piston fluctuates, a control signal from the control unit is output to the flow rate control unit, and the supply amount set in advance in the control unit corresponding to the fluctuation of the weight load is obtained. Supplying pressure fluid to the cylinder chamber through the flow rate controller , and applying a pressing force substantially balanced with the weight load to the piston;
A step of moving the piston by applying a pre-listen power and the pressing force,
It is characterized by having.

According to the present invention, in a cylinder device that can displace a piston under the drive action of a drive unit and move a workpiece via the piston, before the weight load applied to the piston fluctuates , A control signal is output to the flow rate control unit , pressure fluid is supplied to the cylinder chamber at a supply amount set in advance in the control unit in response to the variation in the heavy load, and the pressure of the pressure fluid against the piston is The weight load is substantially balanced, and the piston is moved by applying the driving force of the driving unit and the pressing force of the pressure fluid.

Therefore, when a load fluctuation occurs in the piston by supplying pressure fluid to the cylinder chamber in advance and increasing or decreasing the pressing force in accordance with the fluctuation in the load before the weight load fluctuation in the piston occurs. The driving load on the driving unit can be reduced. In addition, by confirming in advance the amount of variation in the weight load that occurs with respect to the cylinder device and setting the supply amount of the pressure fluid corresponding to the variation amount in the control unit, the weight load on the piston is set. Before the fluctuation is applied, the flow rate control unit is controlled based on a control signal from the control unit, and the pressure fluid having a supply amount corresponding to the load fluctuation can be supplied to the cylinder chamber. Therefore, compared with the control method of the conventional cylinder device, the driving amount of the driving unit can be stabilized even when the weight load applied to the piston fluctuates, and the positioning control of the workpiece is performed through the displacement of the piston. The pressure fluid applied to the piston can be performed with high accuracy, and it is possible to reduce the size and labor of the cylinder device including the drive unit and reduce the manufacturing cost with respect to the conventional cylinder device. The pressing force can be increased or decreased reliably and suitably according to the load fluctuation.

  Furthermore, by setting the timing for supplying the pressure fluid to the control unit in advance so as to be a predetermined time before the timing at which the weight load applied to the piston fluctuates, the weight load generated on the cylinder device can be reduced. It is possible to check the fluctuation timing in advance and set the timing for supplying the pressure fluid to the control unit in accordance with the fluctuation timing. Thus, before the weight load fluctuation is applied to the piston, the pressure fluid is supplied to the cylinder chamber based on the control signal from the control unit, and the pressing force of the pressure fluid biased by the piston is reduced. It can be increased and decreased reliably and suitably according to the fluctuation of the load.

Furthermore, the present invention provides a cylinder apparatus comprising: a piston that is displaceably provided on a cylinder body; a ball screw that engages with the piston; and a drive unit that rotationally drives the ball screw. A drive control method for a cylinder device, wherein the piston is displaced by at least one of the pressure of a pressure fluid supplied to a chamber and the driving force of the driving unit, and the work attached to the piston is moved.
Displacing the piston along the cylinder body via the ball screw under the driving action of the driving unit;
Detecting the drive amount of the drive unit, and comparing the drive amount set with the drive unit set in advance in the control unit;
The setting calculates the supply amount of the pressure fluid corresponding to the difference between the driving amount and the driving amount, and supplying the pressure fluid to the cylinder chamber on the basis of the feed amount,
Is substantially balance and weight is applied to the pressure and the piston of the supplied the pressure fluid load with respect to the cylinder chamber, wherein by applying a driving force the pressing force by the pressure fluid and by the driving part Moving the piston;
It is characterized by having.

  According to the present invention, when the weight load applied to the piston fluctuates in the cylinder device in which the piston is displaced under the driving action of the drive unit and the workpiece can be moved via the piston, the fluctuation of the weight load is changed. Since the drive amount of the drive unit changes accordingly, the detected drive amount is compared with the set drive amount preset in the control unit. As a result, the drive load on the drive unit is confirmed, and a supply amount of pressure fluid corresponding to the difference between the drive amount and the set drive amount is supplied to the cylinder chamber so that the drive load becomes substantially constant.

  Therefore, by controlling the supply amount of the pressure fluid supplied to the cylinder chamber in accordance with the change in the drive amount of the drive unit, the drive amount of the drive unit can be maintained substantially constant and the drive load can be reduced. it can. Therefore, compared with the conventional control method of the cylinder device, the drive amount of the drive unit can be stabilized even when the weight load applied to the piston fluctuates, and the positioning control of the workpiece is enhanced through the displacement of the piston. In addition to being able to perform with high accuracy, it is possible to reduce the size, labor saving, and manufacturing cost of the cylinder device including the drive unit compared to the conventional cylinder device.

Still further, the present invention provides a cylinder apparatus comprising: a piston movably provided on a cylinder body; a ball screw engaged with the piston; and a drive unit that rotationally drives the ball screw. A drive control method for a cylinder device, wherein the piston is displaced by at least one of the pressure of a pressure fluid supplied to a chamber and the driving force of the driving unit, and the work attached to the piston is moved.
Displacing the piston along the cylinder body via the ball screw under the driving action of the driving unit;
Before the weight load applied to the piston varies, the pressure fluid to be supplied amount corresponding to variation of the weight load is supplied to the cylinder chamber, the said weight load and the pressing force substantially balances Giving to a piston or detecting the drive amount of the drive unit, comparing the drive amount with the drive amount set in advance in the control unit, and comparing the drive amount with the set drive amount a step wherein the calculating the supply amount of the pressure fluid, which selectively performs one of or supplying the pressure fluid to the cylinder chamber on the basis of the feed amount corresponding to the difference between,
A step of moving the piston by applying a pre Ki押 pressure and the driving force,
It is characterized by having.

  According to the present invention, in a cylinder device capable of displacing a piston under the drive action of a drive unit and moving a workpiece via the piston, before the weight load applied to the piston fluctuates, the load fluctuates in advance. When a pressure fluid of a corresponding supply amount is supplied to the cylinder chamber and the pressing force of the pressure fluid against the piston and the weight load are substantially balanced, or when the weight load applied to the piston fluctuates, Since the drive amount of the drive unit changes with the change in the weight load, the detected drive amount is compared with the set drive amount set in advance in the control unit, and the drive load is set to be substantially constant. Either one of the supply amount of pressure fluid corresponding to the difference between the drive amount and the set drive amount is supplied to the cylinder chamber, and the piston is moved by the drive force of the drive unit and the pressing force of the pressure fluid. .

  Therefore, by appropriately selecting the optimal control method according to the operating condition of the cylinder device including the piston, the drive unit can be used even when the weight load applied to the piston fluctuates as compared with the control method of the conventional cylinder device. Can be further stabilized, and the positioning control of the workpiece can be performed with high accuracy through the displacement of the piston. As a result, it is possible to further reduce the size of the cylinder device including the driving unit, the labor saving associated with the reduction of the driving torque, and the manufacturing cost with respect to the conventional cylinder device.

  According to the present invention, the following effects can be obtained.

  That is, before the load fluctuation occurs, the pressure fluid is supplied to the cylinder chamber in advance and the pressing force against the piston is increased or decreased according to the fluctuation of the load before the load fluctuation occurs. In addition, the driving load on the driving unit can be reduced. Therefore, compared with the control method of the conventional cylinder device, the drive amount of the drive unit can be stabilized, so that the workpiece positioning control can be performed with high accuracy and the size of the cylinder device including the drive unit can be reduced. Thus, labor saving and manufacturing cost reduction can be achieved.

  Further, by controlling the supply amount of the pressure fluid supplied to the cylinder chamber in accordance with the drive amount change of the drive unit, the drive amount of the drive unit can be maintained substantially constant and the drive load can be reduced. Therefore, even when the weight load applied to the piston fluctuates, the workpiece positioning control can be performed with high accuracy, and the cylinder device can be reduced in size, labor-saving and manufacturing cost compared to the conventional cylinder device. Reduction is possible.

  The drive control method for a cylinder device according to the present invention will be described in detail below with reference to the accompanying drawings by giving a preferred embodiment in relation to the device for carrying out the method.

  In FIG. 1, reference numeral 10 indicates a cylinder device to which the drive control method for a cylinder device according to the first embodiment of the present invention is applied.

  As shown in FIG. 1, the cylinder device 10 includes a pressure fluid supply source 12 that supplies pressure fluid, and an electropneumatic regulator that adjusts and outputs the pressure of the pressure fluid supplied from the pressure fluid supply source 12. A flow rate control unit) 14, a cylinder body 16 that is supplied with the pressure fluid and displaces the workpiece W by a predetermined amount, and a controller (control unit) 18 that outputs a control signal to the cylinder body 16 and the electropneumatic regulator 14. With.

  The pressure fluid supply source 12 is connected to the electropneumatic regulator 14 via a pipe 20a, and the electropneumatic regulator 14 is connected to the cylinder body 16 via a pipe 20b. The controller 18 is connected to the electropneumatic regulator 14, the pressure detection unit 24 that detects the pressure of the cylinder body 16, and the drive unit 34 of the cylinder body 16 via the wirings 22 a to 22 c. 14, a control signal is output to the drive unit 34, and a detection signal detected by the pressure detection unit 24 or the like is input to the controller 18.

  The cylinder body 16 includes a cylinder tube 26, a piston 28 that is displaceable inside the cylinder tube 26, a table portion 32 that is provided on a rod portion 30 of the piston 28 and engages a workpiece W, and the cylinder A drive unit 34 is connected to the end of the tube 26 and is driven to rotate based on a control signal from the controller 18, and a ball screw shaft 36 connected to the drive unit 34 and rotated integrally. This drive part 34 consists of a stepping motor and a DC motor, for example.

  The cylinder tube 26 is formed in a cylindrical shape, and a drive unit 34 is mounted on one end side of the cylinder tube 26, and the rod portion 30 of the piston 28 is inserted on the other end side. A first cylinder chamber 38 is formed inside the cylinder tube 26 between one end of the cylinder tube 26 and the piston 28, and communicates with the outside via the first port 40. On the other hand, a second cylinder chamber (cylinder chamber) 42 is formed between the other end of the cylinder tube 26 and the piston 28, and is connected to the electropneumatic regulator 14 and the pressure fluid supply source 12 via the second port 44. Yes.

  The piston 28 is formed in a substantially T-shaped cross section, and a ball screw shaft 36 is screwed along the axial direction at a substantially central portion thereof, and the piston 28 is attached to the cylinder tube 26 under the rotating action of the ball screw shaft 36. Displaces along. At this time, since the piston 28 is provided with an anti-rotation mechanism (not shown), the piston 28 is not rotationally displaced.

  That is, the cylinder body 16 is configured such that when the piston 28 is displaced along the axial direction under the rotational action of the driving portion 34, the rod portion 30 and the table portion 32 of the piston 28 are displaced along the axial direction. When the pressure fluid is supplied from the second port 44 of the tube 26 to the second cylinder chamber 42, the piston 28 is displaced toward the drive unit 34 (in the direction of the arrow X1) under the pressing action of the pressure fluid. . At this time, the first port 40 is kept open to the atmosphere.

  A mounting table 46 on which the workpiece W is mounted is disposed below the cylinder body 16. The mounting table 46 is formed in a cylindrical shape in which the table portion 32 of the cylinder body 16 can be displaced inside, and a plate-shaped workpiece W is mounted on the open upper end portion. Further, the cylinder body 16 and the mounting table 46 are arranged substantially coaxially.

  In the cylinder device 10 configured as described above, an operation in the case where the workpiece W is raised from the initial position on the mounting table 46 to a predetermined position will be described.

  First, as shown in FIGS. 1 and 2A, the cylinder body 16 is arranged so that the drive unit 34 is on the upper side, and the second port 44 of the cylinder tube 26 is electrically connected to the second port 44 via the pipe 20. An empty regulator 14 and a pressure fluid supply source 12 are connected. A workpiece W is inserted into the rod portion 30 of the cylinder body 16 on the upper side of the table portion 32, and the workpiece W is mounted on the mounting table 46.

  In such an initial state, a control signal is output from the controller 18 to the electropneumatic regulator 14, and a control signal is output from the controller 18 to the drive unit 34. As a result, the pressure fluid from the pressure fluid supply source 12 is supplied to the cylinder body 16 by a predetermined amount by opening the electropneumatic regulator 14 based on the control signal, and the piston 28 of the cylinder body 16 is pressurized. The fluid is pressed toward the drive unit 34 (in the direction of the arrow X1) under the pressing action of the fluid. At the same time, the ball screw shaft 36 is rotated by the drive unit 34 being driven to rotate, and the piston 28 is added to the pressure of the pressure fluid and is engaged with the ball screw shaft 36 (see FIG. It is displaced by a distance L1 in the direction of arrow X1. At this time, since the load on the drive unit 34 is constant, the drive torque of the drive unit 34 is substantially constant as shown in FIG. 3 (see the range A in the drive torque Te in FIG. 3). As a result, the rod portion 30 and the table portion 32 of the piston 28 are raised toward the drive portion 34 (in the direction of the arrow X1) by the pressing force of the pressure fluid supplied to the cylinder tube 26 and the drive force of the drive portion 34. Will be.

  FIG. 3 is a characteristic curve diagram showing the relationship between the displacement position Y of the workpiece W, the pressure P of the second cylinder chamber 42 detected by the pressure detection unit 24, the drive torque Te of the drive unit 34, and the time t. Yes, the characteristic curve shown by the solid line shows the case where the drive control method of the cylinder device 10 according to the first embodiment is applied, and the characteristic curve shown by the broken line shows the characteristic curve of the cylinder device according to the prior art. The case where the control method is applied is shown. Further, the ranges A to E illustrated in FIG. 3 correspond to A to E illustrated for the respective operation states of the cylinder device 10 of FIGS. 2A to 2E.

  And before the table part 32 raises and contact | abuts to the workpiece | work W mounted in the mounting base 46, it presets to the controller 18 so that the pressure of the 2nd cylinder chamber 42 may turn into the desired setting pressure value P1. A control signal is output from the controller 18 to the electropneumatic regulator 14. As a result, the amount of pressure fluid supplied to the cylinder body 16 increases, and the pressure in the second cylinder chamber 42 increases to the set pressure value P1. As a result, the piston 28 is pressed toward the drive unit 34 (in the direction of the arrow X1) with a larger pressing force.

  Specifically, the time from when the piston 28 is displaced from the initial position until it abuts against the workpiece W via the table portion 32 and a load change occurs is measured in advance and set for the controller 18. Then, from the timing when this load fluctuation occurs, that is, when the work W and the table portion 32 come into contact with each other (a boundary portion between the range A and the range B in FIG. 3), the controller 18 performs electropneumatic. A control signal is output to the regulator 14 to supply pressure fluid to the second cylinder chamber 42 of the cylinder body 16.

  A time lag t1 between the timing at which this load variation occurs and the timing at which the supply amount of the pressurized fluid is increased is arbitrarily set according to the timing of the load variation occurring with respect to the piston 28 and is set in the controller 18 in advance. Yes.

  Further, the supply amount (pressure) of the pressure fluid that is additionally supplied to the cylinder body 16 is measured in advance based on, for example, the shape and weight of the workpiece W, and is set in the controller 18. In other words, based on the weight of the workpiece W or the like, the magnitude of the load fluctuation that occurs when the workpiece W is moved is estimated, and the controller 18 controls the pressure fluid supply amount according to the load fluctuation. To do.

  At this time, the pressure in the second cylinder chamber 42 is detected by the pressure detection unit 24 through the pipe 20 b and is output from the pressure detection unit 24 to the controller 18. Then, the controller 18 compares the detected pressure value with a preset value of the pressure fluid, and outputs a difference between the set value and the pressure value to the electropneumatic regulator 14 as a feedback signal. The supply amount of the pressure fluid capable of maintaining the second cylinder chamber 42 at a set pressure is controlled.

  Next, as shown in FIG. 2B, the weight of the workpiece W with respect to the table portion 32 when the table portion 32 abuts against the workpiece W placed on the placement table 46 and separates from the placement table 46. However, since the pressing force toward the drive unit 34 (in the direction of the arrow X1) with respect to the piston 28 is increased by increasing the supply amount of the pressure fluid in advance, when the workpiece W is raised, the drive unit It can suppress that the load by the weight of the workpiece | work W is provided with respect to 34. FIG. At this time, as shown in FIG. 3, the driving torque of the driving unit 34 slightly increases when the workpiece W is separated from the mounting table 46, but since the pressing force by the pressure fluid is applied, The increase amount can be suppressed as compared with the increase amount of the drive torque of the rotary drive source in the conventional cylinder device, and thereafter, it can be driven with a substantially constant drive torque (in FIG. 3, the drive torque Te). In range B).

  In other words, since the piston 28 is preliminarily applied with a pressing force that presses the workpiece W toward the drive unit 34 under the pressing action of the pressure fluid, the workpiece W is engaged with the table portion 32. When raising, the pressing force assists the driving force of the drive unit 34.

  Finally, as shown in FIG. 2C, when the workpiece W is further raised by the distance L2 via the table portion 32, the pressure fluid is supplied to the cylinder body 16 at a substantially constant supply amount, and the second cylinder chamber. While the pressure of 42 is maintained, the drive of the drive part 34 is stopped. That is, the workpiece W is held only by the pressing force of the pressure fluid (see the range C in the pressure P and the driving torque Te in FIG. 3).

  Next, an operation when the work W held by the table portion 32 of the cylinder main body 16 shown in FIG. 2C is lowered and placed on the placement table 46 will be described.

  First, a control signal is output from the controller 18 to the drive unit 34, and when the drive unit 34 is driven to rotate in the opposite direction, the ball screw shaft 36 rotates in the opposite direction and the piston 28 is screwed. Under the combined action, it is displaced in the direction away from the drive unit 34 (the direction of the arrow X2). At this time, since the load on the drive unit 34 is constant, the drive torque of the drive unit 34 is substantially constant.

  A control signal is output from the controller 18 to the electropneumatic regulator 14 and supplied to the cylinder body 16 before the work W is lowered in the direction of the arrow X2 and the work W is placed on the mounting table 46. The supplied amount of pressurized fluid is decreased by a predetermined amount, and the pressure in the second cylinder chamber 42 is lowered. As a result, the pressing force biased toward the drive unit 34 (in the direction of the arrow X1) with respect to the piston 28 is reduced.

  Specifically, the electropneumatic operation is performed by the controller 18 from the controller 18 a predetermined time before the time when the workpiece W is placed on the placement table 46 apart from the table portion 32 (the boundary portion between the range D and the range E in FIG. 3). By outputting a control signal to the regulator 14 and closing the electropneumatic regulator 14, the supply amount of the pressure fluid supplied to the second cylinder chamber 42 is decreased by a predetermined amount.

  Specifically, the time from when the workpiece W is held by the table portion 32 to when the piston 28 descends and the workpiece W comes into contact with the mounting table 46 to cause load fluctuation is measured in advance. Is set. Then, from the timing when this load fluctuation occurs, that is, from the time when the workpiece W and the mounting table 46 come into contact with each other (a boundary portion between the range D and the range E in FIG. 3), the controller 18 performs electropneumatic. A control signal is output to the regulator 14 to reduce the amount of pressure fluid supplied to the second cylinder chamber 42 of the cylinder body 16.

  A time lag t2 between the timing at which the load fluctuation occurs and the timing at which the supply amount of the pressure fluid is decreased is arbitrarily set according to the timing of the load fluctuation generated with respect to the piston 28 and is set in the controller 18 in advance. Yes. The time lag t2 may be set to be equal to the time lag t1 corresponding to the load fluctuation when the work W is held by the table unit 32, or may be set individually.

  Further, the amount of pressure fluid to be reduced with respect to the cylinder body 16 is measured in advance based on the shape, weight, etc. of the workpiece W and set in the controller 18. In other words, based on the weight of the workpiece W or the like, the magnitude of the load fluctuation that occurs when the workpiece W is placed on the placing table 46 is estimated, and the amount of pressure fluid is reduced according to the load fluctuation. It is controlled by the controller 18.

  Next, as shown in FIG. 2D, the load of the workpiece W applied to the table portion 32 by the workpiece W being displaced downward by a distance L2 and being placed on the upper end portion of the placement table 46. Since (weight) is eliminated, the driving load from the workpiece W on the driving unit 34 is reduced. At this time, before the work W is placed on the placing table 46, the pressure fluid supply amount is reduced in advance to reduce the pressing force applied toward the drive unit 34 side (arrow X1 direction) of the piston 28. Therefore, when the work W is placed, the pressing force on the piston 28 does not become excessive, and a sudden load fluctuation does not occur on the drive unit 34.

  Finally, as shown in FIG. 2E, the drive unit 34 is further driven to lower the piston 28 by the distance L1, so that the workpiece W is placed on the placement table 46, and the table portion 32 is placed on the placement table 46. It will return to the initial state arranged inside.

  As described above, in the drive control method for the cylinder device according to the first embodiment, the supply amount of the pressure fluid supplied to the cylinder body 16 via the controller 18 and the electropneumatic regulator 14 is increased or decreased. The pressure of 42 is controlled with high accuracy, and the pressing force by the pressure fluid is increased or decreased in advance before the load fluctuation occurs in the cylinder device 10. As a result, the pressing force of the pressurized fluid applied to the piston 28 and the load fluctuation can be substantially balanced, and the driving load of the driving unit 34 can be reduced, so that the maximum peak of the driving torque in the driving unit 34 is suppressed. (See the solid line and the broken line of the drive torque Te in FIG. 3). Therefore, the capacity of the drive unit 34 can be reduced as compared with the conventional cylinder device, and accordingly, the drive unit 34 can be reduced in size, so that the cylinder device 10 can be reduced in size and labor can be saved. It becomes.

  Further, as compared with the control method of the conventional cylinder device, by suppressing the maximum peak of the drive torque in the drive unit 34 (see the solid line and the broken line in the drive torque Te in FIG. 3), the drive unit 34 is stabilized. It can be driven. Therefore, the displacement of the piston 28 in the cylinder body 16 can be controlled with high accuracy, and the workpiece W can be positioned and controlled with high accuracy.

  The cylinder body 16 described above is not limited to the case where the piston 28 and the ball screw shaft 36 are coaxially disposed, and the piston 28 is a cylinder as in the cylinder device 50 shown in FIG. It may be provided inside the tube 26, and the drive unit 34 and the ball screw shaft 36 may be disposed outside the cylinder tube 26. In this case, the ball screw shaft 36 is screwed into the table portion 32a, and the table portion 32a is directly displaced along the axial direction under the rotating action of the ball screw shaft 36.

  Next, FIG. 5 shows a drive control method of the cylinder device according to the second embodiment. In addition, the same referential mark is attached | subjected to the component same as the drive control method of the cylinder apparatus 10 which concerns on 1st Embodiment mentioned above, and the detailed description is abbreviate | omitted. FIG. 5 is a characteristic curve diagram showing the relationship between the displacement position Y of the workpiece W, the pressure P of the second cylinder chamber 42 detected by the pressure detection unit 24, the drive torque Te of the drive unit 34, and the time t. Yes, the characteristic curve shown by the solid line shows the case where the drive control method of the cylinder device according to the second embodiment is applied, and the characteristic curve shown by the broken line shows the control of the cylinder device according to the prior art The case where the method is applied is shown. Further, A to E illustrated in FIG. 5 respectively correspond to A to E illustrated for each operation state of the cylinder device 10 of FIGS. 2A to 2E.

  In the drive control method for the cylinder device according to the second embodiment, as shown in FIG. 5, the controller 18 detects the drive torque of the drive unit 34 so as to correspond to the increase or decrease of the drive torque. The cylinder according to the first embodiment is configured so that the supply amount of the pressure fluid supplied to the cylinder body 16 through the electropneumatic regulator 14 is increased or decreased by outputting a control signal from the electropneumatic regulator 14 to the electropneumatic regulator 14. This is different from the drive control method of the apparatus.

  In this drive control method, a drive detection unit (not shown) that can detect the rotation angle or rotation amount of the drive unit 34 is provided, and the detection result detected by the drive detection unit is output to the controller 18 as an output signal. Thus, the controller 18 calculates the drive torque from the detection result. A control signal is output from the controller 18 to the electropneumatic regulator 14 so that the driving torque becomes substantially constant, and pressure fluid is supplied to the cylinder body 16 through the electropneumatic regulator 14. That is, when the drive torque of the drive unit 34 increases, the electropneumatic regulator 14 is opened to increase the supply amount of the pressurized fluid, and the pressure in the second cylinder chamber 42 is increased, thereby causing the piston 28 to move to the drive unit 34. Since the load on the drive unit 34 can be reduced by pressing toward the side (arrow A direction), the drive torque decreases. On the other hand, when the driving torque decreases, the supply amount of the pressure fluid is decreased by closing the electropneumatic regulator 14, and the driving torque is increased by decreasing the pressure of the second cylinder chamber 42. .

  Thus, the drive load in the drive unit 34 is always detected by the drive detection unit, and the drive load is output to the controller 18 as the drive torque, so that it is compared with a preset desired drive torque set value, A pressure value of the pressure fluid capable of maintaining the drive torque set value is calculated. A feedback signal based on this calculated value is output from the controller 18 to the electropneumatic regulator 14, whereby the supply amount (pressure value) of the pressure fluid supplied to the cylinder body 16 is controlled, and the piston 28 is supplied to the piston 28. The applied pressing force is controlled. Thereby, the load with respect to the drive part 34 can always be maintained substantially constant. That is, feedback control is performed to detect the drive load of the drive unit 34 and control the supply amount of the pressure fluid so that the drive torque of the drive unit 34 becomes substantially constant according to the drive load.

  As described above, in the drive control method for the cylinder device according to the second embodiment, when the load on the drive unit 34 fluctuates, the second cylinder chamber 42 is changed according to the change in the drive torque of the drive unit 34. By increasing / decreasing the supply amount of the pressure fluid to be supplied, the pressing force to the piston 28 by the pressure fluid and the load fluctuation can be substantially balanced, and the driving load of the driving unit 34 can be reduced. Therefore, compared with the control method of the conventional cylinder device, the maximum peak of the drive torque in the drive unit 34 can be suppressed (see the solid line and the broken line in the drive torque Te in FIG. 5). Since the capacity | capacitance of the drive part 34 can be made small with respect to an apparatus, size reduction and labor saving of a cylinder apparatus containing the drive part 34 can be achieved.

  Further, even when the load fluctuation condition (for example, fluctuation amount, fluctuation timing) in the cylinder device cannot be grasped in advance, a change in the driving torque of the driving unit 34 is detected, and the pressure applied to the cylinder body 16 based on the detection result. Since the supply amount of the fluid can be changed, the driving load on the driving unit 34 can be surely and suitably reduced.

  Next, FIG. 6 shows a drive control method for the cylinder device according to the third embodiment. In addition, the same referential mark is attached | subjected to the component same as the drive control method of the cylinder apparatus 10 which concerns on 1st and 2nd embodiment mentioned above, and the detailed description is abbreviate | omitted. FIG. 6 is a characteristic curve diagram showing the relationship between the displacement position Y of the workpiece W, the pressure P of the second cylinder chamber 42 detected by the pressure detection unit 24, the drive torque Te of the drive unit 34, and the time t. The characteristic curve shown by the solid line shows the case where the drive control method for the cylinder device according to the third embodiment is applied, and the characteristic curve shown by the broken line shows the control method for the cylinder device according to the prior art. The case where it is applied is shown. Further, A to E illustrated in FIG. 6 respectively correspond to A to E illustrated for each operation state of the cylinder device 10 of FIGS. 2A to 2E.

  In the cylinder device drive control method according to the third embodiment, the controller 18 detects the drive torque of the drive unit 34, and the pressure fluid supplied to the cylinder body 16 via the controller 18 and the electropneumatic regulator 14. The control of the pressure in the second cylinder chamber 42 is controlled with high accuracy by increasing / decreasing the supply amount of the gas, and it corresponds to the predictive control for increasing / decreasing the pressing force by the pressure fluid in advance before the load fluctuation occurs in the cylinder device 10, and Then, by outputting a control signal from the controller 18 to the electropneumatic regulator 14, the torque control for increasing or decreasing the supply amount of the pressure fluid supplied to the cylinder body 16 through the electropneumatic regulator 14 is performed. The cylinder mounting according to the first and second embodiments is appropriately selected according to the situation and selectively controlled. It differs from the drive control method for.

  In this cylinder device drive control method, when the load fluctuation position (stroke position of the piston 28) in the cylinder device 10, the load before and after the load fluctuation occurs, and the load fluctuation amount can be accurately detected, When it is difficult to accurately detect the position of the load fluctuation, the load before and after the load fluctuation occurs, and the amount of load fluctuation, the cylinder device 10 performs predictive control and performs the control. Control is performed by selecting torque control in the apparatus.

  That is, in the cylinder device drive control method according to the third embodiment, an optimum control method is determined according to the operating state of the cylinder device 10, and the pressure fluid is used in advance before a load change occurs in the cylinder device 10. Predictive control for increasing the pressing force and torque control for increasing / decreasing the supply amount of the pressure fluid supplied to the cylinder body 16 in response to increase / decrease in drive torque in the drive unit 34 are suitably used to perform combined control. Yes.

  As described above, in the drive control method for the cylinder device according to the third embodiment, as shown in FIG. 7, the predictive control described as the drive control method according to the first embodiment, the second embodiment, Compared with the torque control described as the drive control method according to the embodiment, it is possible to reduce the average power P per process in which the piston 28 strokes in the cylinder device. That is, the drive torque in the drive unit 34 can be further reduced with respect to the cylinder device drive control method according to the first and second embodiments, and accordingly, power saving of the cylinder device can be achieved. Is possible.

  Specifically, by performing predictive control of the cylinder device 10, instantaneous torque during acceleration / deceleration and load fluctuation in the cylinder device 10 can be suppressed, and driving torque in the drive unit 34 is achieved by performing torque control. Can be suppressed.

It is a schematic block diagram which shows the structure of the cylinder apparatus to which the drive control method of the cylinder apparatus which concerns on the 1st Embodiment of this invention was applied. 2A to 2E are operation explanatory diagrams when moving the workpiece placed on the placement table in the cylinder device. 3 is a characteristic curve showing the relationship between the displacement position of the workpiece when the cylinder device is driven as shown in FIG. 2, the pressure in the cylinder body detected by the pressure detection unit, the drive torque of the drive unit, and time. It is a longitudinal cross-sectional view which shows the modification of the cylinder apparatus to which the drive control method of the cylinder apparatus of FIG. 1 was applied. In the drive control method for a cylinder device according to the second embodiment of the present invention, the displacement position of the workpiece when the cylinder device is driven, the pressure in the cylinder body detected by the pressure detection unit, and the drive of the drive unit It is a characteristic curve figure which shows the relationship between a torque and time. In the drive control method for a cylinder device according to the third embodiment of the present invention, the displacement position of the workpiece when the cylinder device is driven, the pressure in the cylinder body detected by the pressure detection unit, and the drive of the drive unit It is a characteristic curve figure which shows the relationship between a torque and time. It is the figure which showed the relationship of the average power in the composite control performed in the cylinder apparatus of FIG. 6, the prediction control of the cylinder apparatus which concerns on 1st and 2nd embodiment, and torque control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 50 ... Cylinder apparatus 12 ... Pressure fluid supply source 14 ... Electropneumatic regulator 16 ... Cylinder main body 18 ... Controller 24 ... Pressure detection part 26 ... Cylinder tube 28 ... Piston 32, 32a ... Table part 34 ... Drive part 36 ... Ball screw Axis 46 ... mounting table

Claims (3)

A pressure fluid supplied to a cylinder chamber of the cylinder body in a cylinder device comprising: a piston movably provided on the cylinder body; a ball screw engaged with the piston; and a drive unit that rotationally drives the ball screw. A cylinder device drive control method for moving the workpiece attached to the piston by displacing the piston by at least one of the pressure and the drive force of the drive unit,
Displacing the piston along the cylinder body via the ball screw under the driving action of the driving unit;
Before the weight load applied to the piston fluctuates, a control signal from the control unit is output to the flow rate control unit, and the supply amount set in advance in the control unit corresponding to the fluctuation of the weight load is obtained. Supplying pressure fluid to the cylinder chamber through the flow rate controller, and applying a pressing force substantially balanced with the weight load to the piston;
Applying the driving force and the pressing force to move the piston;
A drive control method for a cylinder device, comprising: In the drive control method of the cylinder device according to claim 1,
The drive of the cylinder device is characterized in that the timing of supplying the pressure fluid is set in the control unit in advance so as to be a predetermined time before the timing at which the weight load applied to the piston fluctuates. Control method. A pressure fluid supplied to a cylinder chamber of the cylinder body in a cylinder device comprising: a piston movably provided on the cylinder body; a ball screw engaged with the piston; and a drive unit that rotationally drives the ball screw. A cylinder device drive control method for moving the workpiece attached to the piston by displacing the piston by at least one of the pressure and the drive force of the drive unit,
Displacing the piston along the cylinder body via the ball screw under the driving action of the driving unit;
Before the weight load applied to the piston fluctuates, the pressure fluid having a supply amount corresponding to the fluctuation of the weight load is supplied to the cylinder chamber, and the pressing force approximately balanced with the weight load is It is applied to the piston or the drive torque of the drive unit is detected, the drive torque set value of the drive unit preset in the control unit is compared with the drive torque, and the drive torque set value and the Calculating the supply amount of the pressure fluid corresponding to the difference from the driving torque, and selectively performing one of supplying the pressure fluid to the cylinder chamber based on the supply amount;
Applying the pressing force and the driving force to move the piston;
A drive control method for a cylinder device, comprising:

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