JPH0683920B2 - Digital rotary switch - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital rotary cam switch, and in particular,
The present invention relates to a digital rotary cam switch capable of automatically advancing an on / off angle by appropriately calculating an advancing amount corresponding to a press rotation number.

[Prior art]

In the press system, in order to synchronize the operation sequence of the entire press system including the press device and its accessories to the press crank angle, a large number of rotary cam switches that interlock with the crankshaft are provided, and the associated rotary cam switch It is well known that the sequence of each part is controlled in conjunction with on / off. By the way, with the recent computerization of the press control circuit, the output of the encoder connected to the crankshaft (or its equivalent) is digitally counted, and the count value is turned on beforehand by a digital comparator. The so-called digital rotary cam switch, which is compared with the angle / off-angle type, is becoming popular.Since the digital rotary cam switch is not mechanically restricted in the number of arrangement steps unlike the conventional mechanical rotary cam switch, many of the auxiliary mechanisms of the entire system are channels. It has many advantages such as being able to cope with a large number of cases, and being able to set a delicate angle, and is expected to become even more popular in the future. By the way, the press machine generates an ON signal and an OFF signal at an angle faster than the on-angle / off-angle (this angle difference is called an advance angle) according to the number of revolutions per minute (SPM). It is well known that the number of revolutions per minute of the press machine varies. Therefore, in the case of the digital rotary cam switch, the advance angle corresponding to the number of minutes of on-angle / off-angle is stored in advance, and the on-signal is generated at a timing earlier than the on-angle by the advance-equivalent angle. The off signal is generated at a timing earlier than the off angle by an angle equivalent to the advance angle.

[Problems to be Solved by the Invention]

Now, the amount of advance required depends on the number of revolutions per minute of the press machine, so when setting the advance in a conventional digital rotary cam switch, the advance corresponding to the expected number of revolutions per minute is stored. Therefore, there is a problem that the advance angle needs to be stored again when the rotation speed fluctuates for a minute. Of course, in order to solve this problem, it is also possible to store all advance angles corresponding to a number of scheduled minute rotation speeds in advance and select the advance angle according to the detected value of the minute rotation speed.
In this case, a problem arises in that a large memory area is required to store the advance angle for each rotation speed for each minute.

[Means for solving problems]

The present invention has been made in view of such problems,
If the rotation speed data and the advance angle data corresponding to the rotation speed are stored at at least two points, the advance angle data is stored for each rotation speed for the rotation speed included between the two points. It is an object of the present invention to provide a novel digital rotary cam switch capable of calculating an advance angle with practically sufficient accuracy for each rotation speed, even if it is not provided. In summary, the digital rotary cam switch of the present invention: operates the controlled object at the timing when the digitized and input crank angle coincides with the preset on-angle, and the digitized and input crank angle changes. It is premised on a digital rotary cam switch designed to stop the operation of a controlled object at a timing that coincides with a preset off-angle. To achieve the above object, the digital rotary cam switch of the present invention is: press Rotation speed data indicating at least two or more rotation speeds of the device is stored, and advance angle data indicating an advance angle amount required at a rotation speed indicated by the rotation speed data is associated with each rotation speed data. Storage means for storing: Speed detection means for detecting the rotation speed of the press device: Detection of the speed detection means The storage means is searched by the maximum rotation speed data in the rotation speed data smaller than the detected rotation speed, the advance angle data corresponding to the rotation speed data, and the rotation speed larger than the detected rotation speed. Data retrieval means for reading out the minimum rotation speed data in the data and the advance angle data corresponding to this rotation speed data: a change amount of the advance angle data corresponding to the change amount of the searched rotation speed data is used as a proportional coefficient. Computation means for calculating an advance angle corresponding to the rotational speed detected by the proportional operation: subtracting the calculated advance angle from the on-angle and the off-angle to correct the set values of the on-angle and the off-angle. Has been done.

[Action]

That is, in the digital rotary cam switch of the present invention, the rotation speed data at at least two points and the advance angle data corresponding to each rotation speed data are stored in the storage means. During the press operation, the speed detecting means detects the actual rotation speed at the present time, and the storage means is searched by the detected value. Then, the advance angle corresponding to the detected actual rotation speed is calculated, and the set values of the on-angle and the off-angle are corrected.

【Example】

An embodiment of the present invention will be described in detail below with reference to the drawings. First, FIG. 1 shows an operation panel of a digital rotary cam switch according to an embodiment of the present invention.
Above, the digital switch 2 for specifying the channel number of the rotary cam switch and the number of revolutions per minute, the digital switch 3 for specifying the on-angle / off-angle and the advance angle, the crank angle during operation and rotating for the minute when the advance angle is set. Numerical display 4 for displaying the number, numerical display 5 for displaying the channel number to be rewritten when the on-angle and off-angle are rewritten, and the on-angle set for the channel designated by the digital switch 2. Numerical display 6, a numerical display 7 that displays the off-angle set for the channel specified by the digital switch 2, a numerical display 8 that displays the advance when setting the advance, and an on-angle rewrite and Button switch 9 that specifies rewriting of the advance angle, rewriting of the off angle Button switch 10 to a constant, 3 notches switch 11 that specifies one of the configuration mode advance angle setting driving mode ON angle and OFF-angle are arranged appropriately. Next, the principle of the present invention will be described with reference to FIGS. 2 and 3 before showing a specific configuration of the present embodiment. FIGS. 2 and 3 are characteristic diagrams showing the relationship between the rotational speed per minute (horizontal axis) and the advance angle (vertical axis) required at the rotational speed per minute. In FIG. 2 and FIG. Rotation speed per minute is 0 S.PM ~ 250
The case of SPM is assumed. Generally, the revolution speed per minute and the advance angle are proportional in a certain range as shown in FIG. 2, and the advance angle increases linearly with the increase in the revolution speed per minute, but the advance angle depends on the characteristics of each press device. May be a higher-order function of the number of revolutions per minute (for example, a quadratic function). Then, in such a case, as shown in FIG. 3, for example, the relationship between the rotational speed per minute and the advance angle is broken line with the rotational speed per minute (100 S.PM and 200 S.PM in FIG. 3) as the boundary point. By changing the shape likewise, it becomes possible to sufficiently satisfy the relationship between the rotational speed per minute and the advance angle at least practically in the operating region of the press. Therefore, in the present embodiment, the minute rotation speed and the advance angle at the point where the inclination of the characteristic curve of the minute rotation speed and the advance angle changes are stored, and the current value of the minute rotation speed is detected by the encoder during the press operation. If the advance angle becomes a higher-order function of the rotation speed per minute by calculating the advance angle corresponding to the detected rotation speed per minute by the proportional calculation based on the stored value and adjusting the on / off angle. Also, it is possible to perform timing control that is approximately and sufficiently satisfactory. Next, FIG. 4 is a block diagram of a digital rotary cam switch according to an embodiment of the present invention, in which elements already described in FIG. 1 are assigned the same reference numerals as those in FIG. To do. In FIG. 4, 20 is an encoder that is connected to a crankshaft of a press device (not shown) or a position equivalent thereto, and generates a pulse each time the crankshaft rotates by a predetermined unit angle, and 21 is an encoder 20. A counter for counting pulses, and 22 are differentiating circuits for differentiating the output of the encoder 20 with respect to time. Therefore, the count value of the counter 21 indicates the crank angle, and the output of the differentiating circuit 22 indicates the number of revolutions per minute. The digital rotary cam switch of FIG. 4 has n channels (n is an arbitrary natural number) as detection channels, and D1 to Dn
Shows the drive circuit of each of these channels. Since the drive circuits D1 to Dn of each channel have the same configuration, the basic configuration is illustrated only for the drive circuit D1, but each drive circuit D1 to Dn stores a setter 31 that stores an on-angle and an off-angle. A digital comparator 33 that compares the crank angle that is input as the count value of the setter 32 and the counter 21 with the on-angle, a digital comparator 34 that compares the crank angle that is input as the count value of the counter 21 with the off-angle, and a digital comparator 33 It has a flip-flop 35 which is set by the output and reset by the output of the digital comparator 34. Further, R1 to Rn indicate relay coils associated with respective parts of the press system, and each relay coil R1 to Rn is excited by the Q output of the flip-flop 35 of the corresponding drive circuit D1 to Dn. Reference numeral 23 is a decoder that decodes the count value of the counter 21, and the decoder 23 drives the display 4 that displays the crank angle and the number of revolutions per minute. In addition, 24, 25, 26 and 27 also indicate decoders, and the display unit 5 for displaying the channel number by the decoder 24 is the decoder 25.
The display 6 that displays the on-angle by the decoder
The display 7 for displaying the off angle is driven by 26, and the display 8 for displaying the advance angle is driven by the decoder 27. Next, 40 is a main controller constituted by a microcomputer and its attached mechanism, 50 is a memory, 60 is an input interface for inputting the outputs of various switches and sensors to the main controller 40, and 70 is a main controller. Decoder of device output
Reference numeral 23 denotes an output interface to be given to the decoder 27, and reference numeral 80 denotes an interval timer for periodically generating the timing for calculating the advance amount during the press operation. FIG. 5 shows the configuration of the memory 50. The memory 50 has a ROM area for storing programs and a RAM area for storing various data. In this RAM area, an on-angle for each channel is provided. On-angle storage area 51 for storing the off-angle for each channel, off-angle storage area 52 for storing the off-angle for each channel, the rotation speed for minutes and the rotation speed for the minute at the point that becomes the boundary point at which the characteristic curve of the advance angle changes linearly. An advance angle storage area 53 for storing an advance angle corresponding to the number of revolutions per minute. The on-angle storage area 51 and the off-angle storage area 52 are associated with the drive circuits D1 to Dn for each channel in advance. Next, the operation of this embodiment will be described with reference to the above matters and the flowchart of FIG. The operation modes of this embodiment include three types of modes: (a) on / off angle setting mode, (b) advance angle setting mode, and (c) press operation mode. The operation of each of these modes is described above. They will be described below in order. First, the operation of (a) the on / off angle setting mode will be described. The operations to be performed by the operator when setting the on / off angle are (1) switching the 3 notch switch 11 to the SET side. (2) The digital switch 2 is used to specify the channel to be rewritten. (3) The digital switch 3 is used to specify the angle to be set. (4) Button switch 9 when rewriting the on-angle
Also, when rewriting the off-angle, button switch
Press 10. Is a series of procedures. First, when setting the on / off angle, the 3-notch switch 11 is switched to the SET side. Also, the digital switches 2 and 3 show some numerical value regardless of whether or not they have been operated. When the program starts, the main controller 40 gives the value indicated by the digital switch 2 to the decoder 24, and the on / off
The number of the channel for which the off angle is set is displayed on the display unit 5. At the same time, the main controller 40 accesses the on-angle storage area 51 and the off-angle storage area 52 of the memory 50 based on the value indicated by the digital switch 2 for designating the channel number, and turns on the on-state already set for the channel. The data indicating the angle and the data indicating the off-angle are read out and given to the decoders 25 and 26 to be displayed on the displays 6 and 7, respectively. Then, in this state, the main controller 40 operates the 3-notch switch 11
Or, one of the button switches 9 and 10 is operated, and the 3 notch switch 11 or the button switch 9 and 10
Repeat the above steps until any of is operated. Therefore, at this point, the operator can operate the digital switch 2 to freely change the channel number for which the set value is to be rewritten. Similarly, at this time, the operator can freely change the on-angle or off-angle to be rewritten by operating the digital switch 3. Needless to say, when the channel number for which the setting value is rewritten is changed by the switching operation of the digital switch 2, the display on the display unit 5, 6, 7 is changed accordingly. When the operator presses the button switch 9, the output of the digital switch 2 that specifies the channel number accesses the on-angle storage area 51 of the memory 50, and the angle specified by the digital switch 3 is stored in the on-angle storage area 51. Store in the corresponding address. When the operator presses the button switch 10, the memory 50 is output by the output of the digital switch 2 that specifies the channel number.
The off-angle storage area 52 is accessed and the angle designated by the digital switch 3 is stored in the corresponding address of the off-angle storage area 52. Next, the operation in the lead angle setting mode of (b) will be described. The operations that the operator must perform in the advance angle setting mode are (1) switching the 3 notch switch 11 to the OFF SET side. (2) The digital switch 2 is used to specify the number of revolutions per minute at the point where the slope of the characteristic curve of the number of revolutions per minute and the advance angle changes. (3) The digital switch 3 designates an advance angle corresponding to the number of revolutions per minute designated in (2) above. (4) Press the button switch 9. Is a series of procedures. First, when setting the lead angle, the 3 notch switch 11
Can be switched to OFF SET side. When the program starts, main controller 40 sets the leading address of advance angle storage area 53 in the address register (not shown) of memory 50 and reads memory 50. Then, the minute rotation number and the lead angle read from the lead angle storage area 53 are given to the decoders 23 and 27, the minute rotation number is displayed on the display 4, and the lead angle is displayed on the display 8. On the other hand, the operator sequentially sets the rotation speed from the lowest for the minute to set the advance angle in the digital switch 2, and sets the advance angle corresponding to the minute in the digital switch 3 and then presses the button switch 9. More specifically, in the example shown in FIG.

The numerical value [0] is set and the digital switch 3
Against

The numerical value [0] is set. When the button switch 9 is pressed, the main control unit stores the numerical value designated by the digital switch 2 as the number of revolutions per minute at the address designated by the address counter in the advance angle storage area, and The numerical value designated by the switch 3 is stored as an advance angle, and the address counter is incremented by [1]. Then, until the 3-notch switch 11 is operated thereafter, the revolution number and the advance angle are stored for each minute while the address of the advance angle storage area 53 is updated every time the button switch 9 is pressed. If so, the number of revolutions per minute

[0]
And the corresponding advance angle

[0], minute rotation speed [100] and corresponding advance angle [10], minute rotation speed [200] and corresponding advance angle [30], minute rotation speed [250] and corresponding advance The corner [50] is sequentially stored. When the 3 notch switch 11 is operated, the address counter clears the stored contents after the next address of the address indicated at that time, and the setting of the advance angle is completed. Next, the operation in the press operation mode of (c) will be described. In the press operation mode, the operator starts the press device after switching the 3 notch switch 11 to the RUN side. After the operation of the press machine is started, each drive circuit D ₁ ~
Since the operation of Dn is basically the same, only the operation of the drive circuit D ₁ will be described. First, when the press machine starts operating, the encoder 20 generates a pulse, the pulse causes the counter 21 to step up, and the count value of the counter 21 indicates the crank angle. Then, the count value of the counter 21 indicating the crank angle is given to the main control unit 40 via the input interface 60, and the main control unit 40 gives this crank angle to the decoder 23 via the output interface 70 to display it. Display on 4. Further, the count value of the counter 21 indicating the crank angle is the drive circuit.
It is given to the digital comparators 33 and 34 of D ₁ . On the other hand, the pulse generated by the encoder 20 is differentiated by the differentiating circuit 22, and the number of revolutions per minute that is the output of the differentiating circuit 22 is given to the input interface 60. Now, the interval timer 80 periodically gives an interrupt signal to the main controller 40, and every time an interrupt is applied, the main controller 40 calculates and advances an advance angle corresponding to the number of revolutions per minute at that time. Correct the on / off angle for circuit D ₁ . More specifically, the main controller 40 has an input interface 60.
The minute rotation speed given from the differentiating circuit 22 is read via, and the advance angle storage area of the memory 50 is searched by this minute rotation speed. First, the main controller 40 detects the maximum value of the values smaller than the current value of the minute rotational speed detected by the differentiating circuit 22 from the minute rotational speeds stored in the advance angle storage area 53, and at that address. The stored number of revolutions per minute is read as L SPM, and the advance angle stored at the address is read as L advance angle. For example, if the minute rotation speed detected by the differentiating circuit 22 is [150], the maximum value of the minute rotation speed smaller than the minute rotation speed in the advance angle storage area 53 is [100], which corresponds to Since the lead angle is [10], L SPM is [100]
And the L advance angle becomes a value of [10]. Then, main controller 40 detects the minimum value larger than the current value of the minute rotation speed detected by differentiating circuit 22 from the minute rotation speed stored in advance angle storage area 53, and the corresponding address is detected. The number of revolutions per minute stored in is read out as H SPM, and the advance angle stored in the address is read out as H advance angle. The current value of the number of rotations per minute detected by the differentiation circuit 22 is [15
In the case of 0], the minimum value of the minute rotation speed larger than the above minute rotation speed in the advance angle storage area 53 is [200], and the corresponding advance angle is [30], so that H SPM is [200]. ], H
The lead angle is [30]. When the L SPM, L advance angle, H SPM, and H advance angle are read in this way, the main control unit determines the L SPM, L advance angle, H SPM, and H advance angle.
The amount of advance is calculated based on the advance. An arithmetic expression for calculating the amount of advance angle based on these values is shown below. In this equation, SPM is the current value of the number of revolutions per minute detected by the differentiating circuit 22. When the data of FIG. 3 is given to the above equation, the advance amount becomes 20 degrees when the current value of the rotational speed per minute is [150], which satisfies the characteristic curve of FIG. In this way, when the advance angle is calculated to be 20 degrees, for example, the main controller 40 subtracts 20 from the on-angle read from the on-angle storage area 51 of the memory 50 and sets it in the setter 31, and 20 is subtracted from the off-angle read from the off-angle storage area 52 of the memory 50 to set it in the setter 32, and the interrupt processing of this time is ended. As mentioned above, the digital comparator of drive circuit D ₁
The crank angle, which is the count value of the counter 21, is given to one input of 33 and 34. Then, at the timing when the crank angle matches the output of the setter 31, the digital comparator 33 causes the flip-flop 35 to
Is set to excite the relay coil R1, and at the timing when the crank angle coincides with the output of the setter 32, the digital comparator 34 resets the flip-flop 35 to demagnetize the relay coil R1. It is well known that each part of the press system is controlled according to the excitation / demagnetization of the relay coil R1. In the above, the method of setting the advance angle and the on-angle /
Although the off-angle setting method has been mentioned, what is essential in the present invention is that the minute rotational speed and the advance angle at the point where the slope of the characteristic curve showing the relationship between the minute rotational speed and the advance angle changes are stored in advance. Incidentally, the current value of the rotation speed per minute is detected during the press operation, and an appropriate advance angle is calculated by proportional calculation based on the set value immediately before and after the rotation speed of this minute to correct the on / off angle. The advance angle setting method and the on-angle / off-angle setting method can be arbitrarily modified.

【effect】

As described above, according to the present invention, if the rotational speed data and the advance angle data corresponding to the rotational speed are stored at at least two points, it is practical for the rotational speed included between the two points. It is possible to calculate the advance angle with sufficient accuracy, and it is possible to save the trouble of setting the advance angle for each rotation speed and the memory area required for storing the advance angle for each rotation speed.

[Brief description of drawings]

FIG. 1 is a plan view of an operation panel of a digital rotary cam switch according to one embodiment of the present invention, FIGS. 2 and 3 are characteristic diagrams showing the relationship between the rotational speed per minute and the advance angle of the press machine, and FIG. Is a block diagram of a digital rotary cam switch according to one embodiment of the present invention, FIG. 5 is an explanatory diagram of a memory area, and FIG.
The figure is a flow chart showing an example of the operation of the present invention. 2.3 Digi switch 4/5/6/7/8 Indicator 9/10 Button switch 11 3 Notch switch, 20 Encoder 21 Counter, 22 Differentiation circuit 31 32 …… Setter 33 ・ 34 …… Digital comparator 40 …… Main controller, 50 …… Memory 51 …… On-angle storage area 52 …… Off-angle storage area 53 …… Advance storage area

Claims (1)

[Claims] 1. The controlled object is operated at the timing when the digitized and input crank angle coincides with the preset on-angle, and the digitized and input crank angle coincides with the preset off-angle. A digital rotary cam switch configured to stop the operation of a controlled object at a timing stores rotation speed data indicating at least two rotation speeds of a press device, and stores the rotation speed data required at the rotation speed indicated by the rotation speed data. Storage means for storing advance angle data indicating the amount of advance angle associated with each of the rotation speed data, speed detection means for detecting the rotation speed of the press device, and the storage means according to the detection value of the speed detection means. The maximum rotation speed data in the rotation speed data smaller than the detected rotation speed and this rotation speed are searched for the means. Data corresponding to the rotation angle data and the minimum rotation speed data in the rotation speed data larger than the detected rotation speed and the advance angle data corresponding to the rotation speed data, and data searching means for searching. And a calculation means for calculating a lead angle corresponding to the rotation speed detected by a proportional calculation using a change amount of the advance angle data corresponding to the change amount of the rotation speed data as a proportional coefficient, and turning on the calculated advance angle. A digital rotary cam switch characterized in that the set values of on-angle and off-angle are corrected by subtracting from angle and off-angle.