JPH05160Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a sheet folding device that automatically folds sheets conveyed by a belt conveyor after washing, etc. The present invention relates to means for preventing misalignment of folded sheets due to changes in sheet conveyance speed.

[Prior Art] In conventional sheets folding devices of this type, the belt conveyor is Various sheets of different lengths are transported by
It is constructed so that it can always be folded at 1/2 of its length. However, the above electronic control device assumes that the conveyance speed of the belt conveyor is constant.
When the intermediate position of the sheets comes to a position immediately in front of the folding mechanism, the pneumatic folding mechanism is operated to fold the sheets.

[Problem that the invention attempts to solve]

In the conventional sheet folding device with the above configuration, the electronic control device automatically folds sheets according to the length of the sheets, so if the conveyance speed of the belt conveyor is constant, even if the sheet length is Even if the values are different, accurate folding is automatically performed without any special adjustment.

However, if the conveyance speed of the belt conveyor changes for some reason, there will be a discrepancy between the operation timing of the folding mechanism and the actual conveyance position of the sheets, making it impossible to perform accurate folding. In particular, there is a certain time delay after the folding signal is output until the folding mechanism actually operates and the air blowing electromagnetic valve opens, and a positional deviation error occurs due to this time delay. In other words, in general, taking the above time delay into account, the timing at which the folding signal is output from the electronic control device is set to match a position a certain distance before the folding position, but this may change the conveyance speed of the belt conveyor. When it occurs,
Since the amount of movement of the sheet changes during the above-mentioned fixed time delay period, accurate folding cannot be performed. In order to prevent such misalignment of the folding position, conventionally the output comparison setting device was reset according to the speed of the belt conveyor. It was manually adjusted so that the folding signal was output. However, such manual adjustment lacks speed and accuracy, and there has been a strong desire for improvement.

Therefore, an object of the present invention is to provide a sheet folding device that can automatically correct the output timing of the folding signal in accordance with the change even if the conveyance speed of the belt conveyor changes, and can perform accurate folding. do.

[Means for solving problems]

In order to solve the above problems and achieve the purpose, the present invention takes the following measures. That is, the time required for the sheets conveyed to the folding mechanism to pass through a designated position is measured using a circuit consisting of a photoelectric sensor, a counter, etc., and the sheet folding position is determined from the measured time required for the sheets to pass through. (for example, the position of 1/2 of the sheet length). Then, the detected time width is stored in a register, and a time corresponding to the operation delay of the folding mechanism is subtracted from the stored time width.
On the other hand, when the point in time when the leading edge of the sheets reaches the folding position of the folding mechanism is detected, the time width stored in the register is read out at this point, and the contents of the register become zero. A folding signal is given to the folding mechanism to operate it.

[Effect]

By taking such measures, the following effects are achieved. In other words, starting from the time when the leading edge of the sheet reaches the specified position, the time from this point until the folding position of the sheet moves to the folding execution position is detected as a time width according to the conveyance speed of the belt conveyor, and this time is calculated. Since the folding signal is sent at a point in time before the width has elapsed by the operation delay time of the folding mechanism, even if the conveyance speed of the belt conveyor changes, the sheet will be folded at a predetermined timing according to the change. Folding is performed so that the folding position is always the predetermined folding position of the sheet.

〔Example〕

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing the operation timing. In FIG. 1, 1 is a sheet to be folded. This sheet 1 is conveyed at a predetermined speed in the direction of the arrow by a belt conveyor 2, and is moved by an air folding mechanism 3 shown as a block at the bottom of the figure. guided to the installation location. The folding mechanism 3 is operated in response to a folding signal S10 as will be described later, and is provided to automatically fold sheets conveyed by the belt conveyor 2 by jetting air.
4 and 5 are at the specified position P1 of the sheet conveyance path,
A light-emitting element and a light-receiving element are disposed facing each other above and below the belt conveyor 2, and constitute a photoelectric sensor that detects when the sheet 1 passes through a designated position. The output of the photoelectric sensor, ie, the output signal S1 of the light receiving element 5, is input to one input terminal of the AND gate 6. At the other input terminal of this AND gate 6,
A reference clock signal S2 applied to terminal 7 is supplied. Therefore, from the AND gate 6, only the period corresponding to the time width of the signal S1 from the light receiving element 5,
A reference clock signal S2 is output, which is input to the sheet length measuring counter 8 and counted. Thus, the time from the time t1 when the leading edge 1a of the sheet 1 reaches the specified position P1 to the time t2 when the rear end 1b of the sheet 1 finishes passing through the specified position P1, that is, the time is determined by the sheet length and the conveyance speed of the belt conveyor. The required passing time TA is measured. This measured time width signal S3 is divided into two by the 1/2 circuit 9, and a signal S4 indicating a time width TA/2, which is half of the required passage time TA, is generated. This signal S4 is input as an addition signal to the register 10 constituting a reversible counter.

On the other hand, the rising portion of the output signal S1 of the light receiving element 5 is input to the timer 11 as a starting signal. This timer 11 is provided to output a time signal S5 equivalent to the operation delay of the folding mechanism 3, and the time signal S5 is outputted to the AND gate 12.
is supplied to one input end of the . and gate 12
The reference clock signal S2 is supplied from the terminal 7 to the other input terminal of the circuit. Therefore, the AND gate 12 outputs the time signal S5 from the timer 11.
The reference clock signal S2 is output for a time width of
This is input to the register 10 as a subtraction signal. Therefore, a data signal corresponding to the operation delay time TC of the folding mechanism 3 is subtracted from a data signal corresponding to the time width TA/2 stored in advance in the register 10. Therefore, in the register 10, a data signal corresponding to the time width TA/2 in which the operation delay time TC of the folding mechanism 3 has been corrected is stored and held.

On the other hand, a rotary encoder 13 is attached to the drive roller shaft 2a that drives the belt conveyor 2, and the output signal of this encoder 13 is
S6 is converted by the frequency converter 14 into a pulse signal S7 having a frequency ten times higher, for example, and is supplied to the preset counter 15. A preset value corresponding to the time TB for the leading edge 1a of the sheet 1 to move from the specified position P1 to the folding position of the folding mechanism 3 is preset in the preset counter 15 by a signal from the terminal 16. When the output signal S1 of the light receiving element 5 is input to the preset counter 15, it starts counting the signal S7 supplied from the frequency converter 14 at the rising edge time t1 of the signal. When the leading edge 1a of the sheet 1 reaches the folding position of the folding mechanism 3, the count value reaches the preset value, and at that time t3, the signal S8 is output. This signal S8 is given to the read circuit 17 as a register contents read command signal. The readout circuit 17 reads out the data signal corresponding to the auxiliary time width TA/2-TC stored in the register 10 in response to the reference clock signal. When the contents of the register 10 become zero by this reading, at that point
At t4, an output command signal S9 is sent out and given to the output circuit 18. Therefore, the output circuit 18 is activated and supplies a folding signal S10 to the pneumatic folding mechanism 3. Thus, the pneumatic folding mechanism 3 moves to the time t5, which is delayed by the time TC from the time t4, as indicated by M in FIG.
The solenoid valve is opened and air is injected to fold the sheet 1.

FIG. 3 is an explanatory diagram of the operation of this embodiment. In the figure, P1 is the tip position of the sheet, P2 is the center position of the sheet,
P3 indicates the rear end position of the sheet. Further, R indicates a specified position, V indicates a folding signal generation position (variable), and W indicates a folding execution position. Further, TA indicates the time required for the sheet 1 to pass through the specified position (variable), TB indicates the time it takes for the leading edge of the sheet to move from the specified position R to the folding execution position W (variable), and TC indicates the operation delay time of the folding mechanism 3 (constant). .

In order for the sheet 1 to be folded accurately at the intermediate position P2, when the intermediate position P2 of the sheet 1 comes to a position V that is before the folding execution position W by the operation delay time TC of the folding mechanism 3, the folding signal is activated. It is enough if S10 occurs. Therefore, from the time t1 when the leading edge of the sheet 1a reaches the specified position R, the time TB for moving to the folding execution position W and 1/2 of the time TA required for the sheet 1 to pass through the specified position R are added,
The folding signal S10 may be output at time t4 when a time T obtained by subtracting the operation delay time TC of the folding mechanism 3 from this added time has elapsed. That is, the above time T can be expressed as T=TB+TA/2-TC. In this embodiment, the time width TA/2, which is 1/2 of the time TA required for the sheet 1 to pass through the specified position R, is first stored in the register 10,
Next, the operation delay time TC of the folding mechanism 3 is subtracted from the memorized time width, and from the time t3 when the time TB for the leading edge 1a of the sheet 1 to move from the specified position R to the folding execution position W has elapsed, the above-mentioned memory At time t4, the folding signal S10
I am trying to send out the following. In other words, the above equation is executed in a modified form as shown in the following equation.

T=TB+(TA/2-TC) According to this embodiment, even if the conveyance speed of the belt conveyor 2 changes, the sheet 1 is always accurately folded at the intermediate position. That is, let us now assume that the conveyance speed of the belt conveyor 2 has decreased to half of the specified speed. Then, both times TA and TB are detected as twice the standard time. In other words, the time required for the sheet 1 to pass through the specified position R is doubled, but this extended time is sampled accurately by the reference clock signal S2 and counted by the counter 8, so that it is equal to the standard time. It is stored in the register 10 as a double time width of 2TA. Furthermore, since the frequency of the pulse signal from the encoder 13 is halved, the time required for the count value of the preset counter 15 to reach the preset value by inputting the pulse signal is twice the standard time. That is, TA and TB are detected as time widths according to the speed of the belt conveyor 2.

On the other hand, the time width TC is a fixed period of time formed by the timer 11. Therefore, even if the speed of the belt conveyor 2 changes, the value of TC does not change. Therefore, the time for the intermediate position P2 of the sheet 1 to reach the folding execution position W is twice as long as the standard time due to the reduction in the speed of the belt conveyor 2, but the intermediate position P2 of the sheet 1 reaches the folding execution position W. Since the folding signal S10 is issued at a time TC time before the time TC, when the intermediate position P2 of the sheet 1 reaches the folding execution position at half the speed mentioned above after the time TC, the folding by the folding mechanism 3 will be performed accurately. It is done. Therefore, the belt speed is between 5m/min and 45m/min.
Even if the speed changes by a few minutes, the operation basically operates according to the above-mentioned operating principle, so that accurate folding is always performed regardless of the degree of speed change.

It should be noted that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effect of idea]

According to the present invention, the starting point is when the leading edge of the sheet reaches a specified position, and the time from this point until the folding position of the sheet moves to the folding execution position is detected as a time width that corresponds to the conveyance speed of the belt conveyor. However, since the folding signal is sent at a point earlier than the elapsed time point by the operation delay time of the folding mechanism, even if the conveyance speed of the belt conveyor changes, the folding signal will be sent in accordance with the change. The output timing of is automatically corrected,
It is possible to provide a sheet folding device that can perform accurate folding.

[Brief explanation of the drawing]

1 to 3 are diagrams showing one embodiment of the present invention, in which FIG. 1 shows the overall configuration, FIG. 2 shows the operation timing, and FIG. 3 is an explanatory diagram of the operation. 1... Sheets, 2... Belt conveyor, 3...
Air type folding mechanism, 4... Light emitting element, 5... Light receiving element, 6, 12... AND gate, 13... Rotary encoder.

Claims (1)

[Scope of utility model registration request] A folding mechanism operated by a folding signal and provided to fold each sheet conveyed by a belt conveyor, and the time required for the sheets conveyed to this folding mechanism to pass through a designated position. means for detecting the time width corresponding to the sheet folding position from the time required for the sheets to pass measured by this means; a register for storing the time width detected by this means; and a register for storing the time width detected by this means. means for subtracting a time equivalent to the operation delay of the folding mechanism from the time width of the folding mechanism, and reading out the time width stored in the register at the time when the leading edge of the sheets reaches the folding position of the folding mechanism. A sheet folding device comprising means for executing the folding mechanism, and means for applying a folding signal to the folding mechanism to operate the folding mechanism when the contents of the register become zero as a result of reading by the means.