JP3143204U - Cam sequencer - Google Patents

Abstract

Provided is a cam sequencer that is easy to use for a user with a simplified circuit and cost reduction.
A rotation potentiometer 1 without a stopper is adopted as a rotation angle sensor, and the circuit is simplified. The discontinuous voltage change that occurs when the potentiometer rotates from 0 to 360 degrees or reverse is handled by software. Each output angle range setting has upper and lower limits, window setting function and hysteresis function, output logic selection and setting, enable input that can set output OFF all at once, and signal input voltage A / There is a mode for always outputting the D conversion result to the USB communication line.
[Selection] Figure 1

Description

  The present invention relates to a cam sequencer for controlling the operation of a target apparatus by signal processing of an angle detection potentiometer output.

  It changes to a cam mechanism that executes a one-cycle sequence while the rotating shaft makes one rotation, and the angle is detected electrically, the angle range is specified, and signal output is turned on and off within the specified range and outside the specified range Conventionally, in an electronic cam apparatus that performs the above, in a programmable cam apparatus or the like, the angle is detected by a resolver, an optical absolute encoder, or an incremental encoder as a sensor that detects a rotation angle.

An example is shown in FIG. This electronic cam switch includes an encoder input circuit 50, a control means 51, an LCD driver 52, an LCD display 53, a storage means 54, a key switch 55, and an output circuit 56. Here, the encoder input circuit 50 specifically detects the angle with a resolver, an optical absolute encoder, and an incremental encoder.
JP 58-222306 A

  There was no cam sequencer that used a potentiometer for the rotation angle detection sensor and converted the output voltage into an angle for use in control.

  In order to use a potentiometer to detect the rotation angle, there is a mechanism that can detect the range of operation of the potentiometer from 0 to 360 degrees and that the rotation can continue in the forward and reverse directions. That is.

  For this purpose, a function in which the angle and the voltage are proportional to each other is required, and the switching of the voltage generated when one rotation is passed (FIG. 2), that is, 360 degrees (4.5 V) to 0 degrees (0. 5V) and at the time of reverse rotation, when the voltage level changes from 0 degree (0.5V) to 360 degree 4.5V), the maximum voltage (4.5V) and the minimum voltage (0.5V) at the time of forward rotation The distance changes discontinuously, for example, between 0.1 degrees, and this change is the same as a voltage that changes from 0 degrees to 360 degrees in normal forward rotation.

  As shown above, when a potentiometer is used, when the output is set to be turned on and off by a voltage according to the angle between 0 degrees and 360 degrees, a normal change and a change in switching are discriminated. In particular, when the rotation speed is slow, the time of the changing angle becomes long, so the setting condition satisfies the condition for turning on and off the output in relation to switching through the set voltage range, so the output is unexpected. The phenomenon of turning on / off occurs.

  An object of the present invention is to solve the above-described problems, to recognize a change point even at a low speed, to prevent the output from being turned on and off unscheduled, and to provide an inexpensive and easy-to-use cam sequencer.

  In order to solve the above problem, in a cam sequencer that uses a rotation potentiometer without a stopper that can detect a range of 0 to 360 degrees in an angle detection sensor and processes and controls the obtained signal, A / D conversion is performed on the corresponding voltage signal, and when this value is within the two-point range of the upper limit value and lower limit value individually stored for each output, it is determined that it is within the specified angle, and the output is turned on. If it is outside the range of two points, it is judged that the angle is outside the specified angle, and the output is turned off (when the output logic inversion function is disabled). There is no need to make any settings. (Claim 1)

The rotation potentiometer without stopper is a mechanism that can continuously rotate from 0 degree to 360 degrees on the forward and reverse sides, and outputs a voltage corresponding to the angle. (Figure 2)
(For example, 0 degree voltage is 0.5V, 360 degree voltage is 4.5V)

  When discontinuous voltage change occurs from 360 degrees to 0 degrees during forward rotation and from 0 degrees to 360 degrees during reverse rotation, the change in voltage input from the sensor is the difference between the previous time and the previous time. When the change is greater than the predetermined value, it is determined that the change has occurred, and the data that has been moving average processed by that time is discarded, and the angle is changed by rewriting all of them to the current value. By immediately switching the value to 0 degree or 360 degrees, voltage changes from 360 degrees to 0 degrees during forward rotation and 0 degrees to 360 degrees during reverse rotation are detected, and the corresponding processing is performed unexpectedly by software. Does not cause output changes. (Claim 2)

  Create a logic inversion setting function. When switching from 0 degrees to 360 degrees, for example, to turn on from 350 degrees to 5 degrees of the next rotation, set a voltage corresponding to 5 degrees to 350 degrees and enable the output logic inversion setting function. For example, it is possible to set from 350 degrees across the change point of switching to 5 degrees of the next rotation. (Claim 3)

  By providing a hysteresis function to stabilize the determination and enabling variable setting, the phenomenon of output chattering at the setting boundary can be prevented according to the installation environment. (Claim 5)

  There is an enable input to prevent unexpected operation of the output. When the enable input is off, all the outputs are fixed to be off, and safety is protected against unexpected operations and voltage changes. (Claim 4)

  The cam sequencer of this device detects the angle from 0 degrees to 360 degrees as an angle detection sensor, and the angle is detected by using a rotation potentiometer without a stopper, so that the electronic circuit is remarkably simplified compared to a resolver or encoder. The cost can be reduced and the cost of automation can be reduced.

  With multiple cam output points, programmable ON / OFF conditions can be set, and timing output can be set easily within one rotation, eliminating the need for feedback sensors, enabling automation with open-loop control, and reverse rotation. Since the output can be turned on and off in the same way as the rolling operation, the adjustment and maintenance of the device becomes easy.

Since it has a hysteresis setting function for stable control execution, it can be controlled with chattering setting, and when output on / off is not required, the output can be fixed to off at once. The functions can be used to optimally meet various automation needs.

FIG. 3 is a diagram illustrating an example of pick and place control using the cam sequencer. In this example, a cam sequencer 26 is connected to the rotary shaft 24 of the press machine 23 by a coupling 25, and the operation is performed in synchronization with one cycle of the press machine. When the set voltage is set and the press machine 23 is operated, the upper and lower 1 solenoid valves 21 are turned on when the rotation axis is 40 degrees, the upper and lower cylinders 27 are lowered, and the chuck solenoid valve is positioned at an angle of 70 degrees. 22 is turned on and chuck 29 is performed. At an angle of 90 degrees, the upper and lower solenoid valves 21 are turned off and the upper and lower cylinders 27 are raised. At an angle of 130 degrees, the front and rear solenoid valves 20 are turned on and the front and rear cylinders are turned on. 28 is advanced, the upper and lower cylinders 27 becomes vertical second solenoid valve 21 ^'is turned on at the position of 190 degrees is lowered again, chuck solenoid valve 22 is turned off at the position of 230 degrees, the chuck 9 releases the workpiece, taken vertically second solenoid valve 21 ^'is turned off at the position of 260 degrees, the vertical cylinder 27 is raised, since the electromagnetic valve 20 is turned off before and after at the position of 280 degrees, the front and rear cylinders 28 It moves back and returns to the initial position, and performs pick-and-place operation. Since it is used in an open loop that does not require a feedback signal for cylinder operation check, it is different from the normal sequence, and costs required for wiring and installation A lot of merit is born, such as drastically reducing and improving maintainability.

  This cam sequencer is a control device that controls the operation of the target device by converting the analog signal output from the rotation potentiometer without stopper that detects the rotation angle into a digital signal and processing the obtained signal. Can be widely used in various industries. For example, it is an effective device for performing a sequence operation without requiring a special skill by controlling the pick-and-place, transfer line, inspection timing start signal and operation start timing signal in the above example.

  Since this cam sequencer does not require a feedback signal to execute the sequence, work such as sensor wiring and sensor mounting is unnecessary, and the operation sequence only sets the voltage of the operation position angle, so the work can be completed in a short time. At the same time, since the wiring of the movable part is unnecessary, it is an extremely useful device that does not cause trouble such as disconnection.

Block diagram showing the configuration of the cam sequencer of the present invention The figure which shows the relation between the angle of the potentiometer and the output voltage in the cam sequencer of the present invention Diagram showing an example of pick and place control using the cam sequencer of the present invention Block diagram showing a configuration example of a conventional electronic cam switch

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Potentiometer 2 L / P filter 3 Power supply circuit 4 A / D converter 5 Comparator 6 Output control circuit 7 Data storage part 8 USB communication circuit 9 USB connector 10 Output connector 11 Output enable circuit 12 Output logic setting circuit

20 Front / rear solenoid valve 21 Upper / lower 1 solenoid valve 21 ^' Up / down 2 solenoid valve 22 Chuck solenoid valve 23 Press machine 24 Press machine rotary shaft 25 Coupling 26 Cam sequencer 27 Upper / lower cylinder 28 Front / rear cylinder 29 Chuck

DESCRIPTION OF SYMBOLS 50 Encoder input circuit 51 Control means 52 LCD driver 53 LCD display 54 Memory | storage means 55 Key switch 56 Output circuit

Claims (5)

  The angle range voltage detected by the rotation angle detection sensor is individually set to two values, an upper limit and a lower limit, for each of a plurality of outputs, and when the current value is within the voltage range corresponding to the voltage of the set angle, A cam sequencer that is turned off at other times and uses a rotation potentiometer without a stopper to detect the rotation angle, and does not require forward rotation or reverse rotation.   2. The cam sequencer according to claim 1, wherein the software performs a moving average of the input values to stabilize the A / D conversion value, from 360 degrees during forward rotation to 0 degrees, and 0 degrees during reverse rotation. When the A / D conversion value changes greatly when switching from 360 to 360 degrees, the function of judging the switching by software, discarding the moving average value, and updating the current value to the A / D conversion value Cam sequencer with   3. The cam sequencer according to claim 1, wherein the output sequence of the cam sequencer can be reversed, and includes all switching operations including switching from 360 degrees to 0 degrees during forward rotation or from 0 degrees to 360 degrees during reverse rotation. Cam sequencer with a function that can be set to an angle.   4. The cam sequencer according to claim 1, wherein the cam sequencer has an enable function for forcibly turning off outputs collectively.   5. The cam sequencer according to claim 1, further comprising a hysteresis function that can be variably set.

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