JP3074307B2 - Intermittent coating position shift prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing displacement of a coating position in an intermittent coating apparatus which repeatedly applies a specific pattern while moving an object to be coated in a predetermined direction.

[0002]

2. Description of the Related Art In the manufacturing process of a disposable diaper, for example, a predetermined pattern is repeatedly applied at intervals corresponding to one disposable diaper while moving a long nonwoven fabric as a material at a constant speed. This coating is performed by opening and closing a discharge valve to discharge hot melt, which is a coating material, from a nozzle.
For example, as disclosed in Japanese Patent Application Laid-Open No. 60-53283, a control valve for operating an air cylinder by an air solenoid valve is widely used.

[0003]

However, in the above control valve, there is a time delay from the input of the valve opening / closing signal to the air solenoid valve to the completion of the opening / closing operation of the discharge nozzle. However, there is a problem that the coating start position or the coating end position deviates from the set position according to the moving speed of the object to be coated. In addition, the time delay varies depending on the applied voltage of the solenoid, the air pressure, the viscosity of the viscous fluid as a coating material, and the like.

[0004] Therefore, an object of the present invention is to make it possible to correctly apply a coating at an appropriate set position regardless of the moving speed of the object to be coated.

[0005]

In order to solve the above problems, the present invention employs the following configuration. That is, the displacement prevention apparatus according to the present invention opens and closes the discharge valve while moving the object to be coated at a constant speed, and intermittently discharges the coating material composed of a high-viscosity fluid from the nozzle to form a specific pattern. A coating position shift prevention device for a coating device that repeatedly performs coating, wherein a pulse signal generating unit that generates a pulse signal proportional to a moving distance of a coated object and a coating start position of the coated object Target signal generating means for detecting a reference position provided on the lower side in the moving direction and generating a target signal,
Counting the number of pulse signals of the pulse signal generating means based on the target signal from the target signal generating means,
A valve opening / closing control means for issuing a valve opening / closing signal to open / close the discharge valve when a predetermined count is reached, and a delay time from when the valve opening / closing signal is transmitted to when coating is actually started or stopped. It is characterized by comprising delay amount setting means capable of presetting the number of pulses corresponding to the distance the coated body moves, and operation delay compensation means for increasing the output timing of the valve opening / closing signal by the set number of pulses. I have. The delay amount is set by providing a sensor that detects that the discharge valve is actually opened and closed, detects the time difference from when the valve open / close signal is issued to when the valve is actually opened, and based on the detection result. It is effective to compensate for the next coating cycle.

[0006]

During operation, the object to be coated is moved in a certain direction, and a pulse signal according to the moving distance is generated by the pulse signal generating means. When the target position is detected by the target signal generation means, a target signal is generated. The number of pulses after the target signal is transmitted is counted, and the workpiece moves during the delay time from the number of pulses corresponding to the distance from the coating start position on the workpiece to the nozzle at that time. An opening / closing signal to the discharge valve is issued when the number of pulses reaches the number of pulses obtained by subtracting the number of pulses corresponding to the distance. In this manner, the valve opening / closing signal is issued by subtracting the number of pulses corresponding to the distance that the object moves during the delay time of the valve opening / closing operation from the number of pulses corresponding to the predetermined moving distance. Can be compensated, and the target position can be coated accurately.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention, in which a coating apparatus 1 performs coating while moving a sheet-like body 5 to be coated in a direction indicated by an arrow X by a pair of rollers 2 as transfer means. The moving speed of the object 5 can be detected because the pulse generator 7 (pulse signal generating means) provided on the roller pair transmits a pulse signal proportional to the moving speed of the object. .

A discharge nozzle 10 of a discharge device 9 is provided above the object to be coated, and as shown in FIG. 2, a coating material cylinder 16 to which a hot melt 15, which is a coating material, is supplied. And an air cylinder 19 to which air for opening / closing operation is supplied are provided integrally with the same axis.
A piston 20 is provided in the air cylinder 19, and a discharge valve 21 is provided in the coating material cylinder 16. The piston 20 and the discharge valve 21 are integrally connected by a piston rod 22 so that the discharge valve 21 moves up and down in accordance with the vertical movement of the piston 20.
The interior of the coating material cylinder 16 is divided into upper chambers 16a by a partition plate 23.
And the lower chamber 16b, and both chambers communicate with each other through a through hole 25 provided in the partition plate. A supply pipe leading to the coating material tank 27 via a gear pump 26 is connected to the lower chamber 16b, and a reflux pipe 29 is connected to the upper chamber 16a.

A hollow portion 31 serving as a coating material reservoir is formed at the base of the nozzle 10, and the hollow portion 31 communicates with the lower chamber 16 b through a fine hole 33. And the hollow part 31
A discharge hole 34 is formed at the front end of the nozzle. The through-hole 25 and the fine hole 33 are connected to the discharge valve 2.
1 selectively closes. That is, when the discharge valve 21 moves upward, the passage 25 is closed, and when the discharge valve 21 moves downward, the pore 33 is closed.

An air supply pipe 37, 3 is connected to the air cylinder 19 through a solenoid valve 36 for opening and closing the nozzle.
8 are connected.

A target signal generator 41 having a photo sensor 41 a is provided at a position lower than the discharge nozzle 10 on the movement path of the object 5 to be coated, and is connected to a controller 40. . The target signal generator 41 detects a mark at a reference position attached to the workpiece 5 in advance and transmits a target signal. Also,
The pulse generator 7 generates a pulse signal proportional to the moving distance of the object 5 to be applied.
4 and are input to counters 43 and 45. 46 is a timer for setting the delay time, and 47 is a register.

Next, the operation of the coating apparatus will be described. A coating portion AB sandwiched between a coating start position A and a coating end position B is set at a predetermined interval on the object 5 to be coated. The reference position (target) P is set at a fixed position on the downstream side in the traveling direction from the coating start position A.
When the object 5 is fed at a constant speed in the direction of the arrow and the reference position P reaches the position C of the sensor of the target signal generator 41, the sensor detects the reference position (target) P and outputs the target signal. Is issued. This signal is sent to gates 42 and 44. Then, the gate 42 is opened by this signal, and the pulse signal from the pulse generator 7 starts to be counted by the counter 43. on the other hand,
After the solenoid valve 36 is energized, the nozzle 10
, A delay time (T) from when the coating material starts to be discharged is actually measured and set in the timer 46 in advance. This timer 46
The gate 44 is opened / closed by the counter 45, and the number of pulses (ND) corresponding to the delay time (T) is counted by the counter 45. Further, the distance from the discharge position S of the nozzle 10 to the coating start position A of the workpiece 5 is set in the register 47 in advance as the number of pulses (N ₁ ). Register 47 subtracts the number of pulses ND corresponding to the time delay from the pulse number _{N 1,} and supplies the difference to _(N 1 -ND) to the counter 43. The counter 43 counts the number of pulses from the pulse generator 7 after the gate 42 is opened, and supplies an open signal to the solenoid valve 36 when the counted number becomes equal to (N ₁ −ND). The solenoid valve 36 is opened by this signal, and the operation air is supplied to the air cylinder 1.
Since the liquid is supplied to the lower side of the piston 20 in the nozzle 9, the piston 20 moves upward, the discharge valve 21 moves upward, and the coating material is supplied from the fine holes 33 to the nozzle 10. Therefore, the nozzle 10
The coating material is discharged from, and the coating is performed. The counter 43 is set count N ₂ corresponding to a preset coating range A-B is closed gate 42 when the counted number N ₂ is counted from the solenoid open signal generation point, solenoid valve The power supply to 36 is stopped. For this reason, the solenoid valve is switched, and the operation air is supplied to the upper side of the piston 20 to close the pore 33 communicating with the nozzle 10 and open the communication port 25 to circulate the coating material. It should be noted that a new sheet 5 'is superimposed on the object 5 to be coated after the coating, and cutting is performed on the lower side by a cutter. This cutter performs a cutting operation in synchronization with opening and closing of a discharge nozzle.

As described above, the coating apparatus 1 compensates for the response delay (usually several tens of milliseconds) of the solenoid valve, the discharge valve, etc., in advance, so that the displacement of the coating can be prevented. it can.

FIG. 3 shows an example slightly different from that described above. A sensor 50 for detecting that the discharge valve 21 is actually opened or closed is attached to the discharge device 9 'of the coating device 1'. Thus, the timer 46 as in the above embodiment is not provided. Other parts are almost the same as those of the above-mentioned embodiment, and the same parts are denoted by the same reference numerals. In this embodiment, corresponding to the opening and closing signal is sent to the solenoid valve 36 from the counter 43 actually counts emanating from Parusuji E Nereta 7 until discharge valve 21 is opened and closed (ND ') That delay amount The number of pulses to be applied is counted by the counter 45 and used as the number of pulses for compensation in the next coating cycle. That is, in the next coating cycle, the ND 'is subtracted by the register 47 from the pulse number N ₁ corresponding to the distance from the position S of the discharge nozzle to the discharge starting position A. Then, the difference (N ₁ −ND ′) is counted by the counter 43.
Is counted, the solenoid valve 36 is opened and closed. According to this embodiment, even if the response delay time of the solenoid valve or the like is not set in advance as a constant value, the delay time in the first coating is detected and the next coating is compensated. Correspondingly, more accurate compensation can be performed.

[0015]

As is apparent from the above description, the position shift preventing apparatus according to the present invention compensates for the response delay of the coating apparatus and effectively prevents the position shift of the coating in intermittent coating. Became possible.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a discharge device.

FIG. 3 is an explanatory view of another embodiment.

[Explanation of symbols]

 Reference Signs List 1, 1 'Coating device 2 Moving device 5 Coating object 7 Pulse generator (pulse signal generating means) 10 Discharge nozzle 21 Discharge valve 36 Solenoid valve 40 Control device 41 Target signal generator 42, 44 Gate 43, 45 Counter 46 Timer 47 Register 50 Sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B05C 5/00-5/02 B05C 13/00, 13/02 B05D 1/26 B05C 1/00

Claims (2)

(57) [Claims] 1. A coating apparatus for opening and closing a discharge valve while moving an object to be coated at a constant speed, intermittently discharging a coating material composed of a high-viscosity fluid from a nozzle, and repeatedly coating a specific pattern. Coating position deviation prevention device, wherein a pulse signal generating means for generating a pulse signal proportional to the moving distance of the object to be coated, and provided in the moving direction lower side than the coating start position of the object to be coated A target signal generating means for detecting a reference position and generating a target signal, and counting the number of pulse signals of the pulse signal generating means based on the target signal from the target signal generating means. Valve opening / closing control means for opening / closing the discharge valve by issuing an opening / closing signal; and the object to be coated moves during a delay time from when the valve opening / closing signal is transmitted until coating is actually started or stopped. A delay amount setting means capable of presetting the number of pulses corresponding to a predetermined distance, and an operation delay compensating means for advancing the output timing of the valve opening / closing signal by the set number of pulses. Device for preventing misalignment. 2. A coating apparatus that opens and closes a discharge valve while moving an object to be coated at a constant speed, intermittently discharges a coating material composed of a high-viscosity fluid from a nozzle, and repeatedly applies a specific pattern. Coating position deviation prevention device, wherein a pulse signal generating means for generating a pulse signal proportional to the moving distance of the object to be coated, and provided in the moving direction lower side than the coating start position of the object to be coated A target signal generating means for detecting a reference position and generating a target signal, and counting the number of pulse signals of the pulse signal generating means based on the target signal from the target signal generating means. A valve opening / closing control unit that issues an opening / closing signal to open / close the discharge valve, a sensor that detects that the nozzle has actually opened / closed, and a nozzle that actually opens / closes after the valve opening / closing signal is issued Intermittent coating comprising an operation delay compensating means for increasing the output timing of the valve opening / closing signal in the next coating cycle by the number of pulses corresponding to the distance that the object moves during the delay time before the coating. Device for preventing misalignment.