JPH1052665A - Discharge nozzle for viscous fluid - Google Patents

Abstract

(57) [Problem] To prevent a viscous fluid such as vaporized glue from entering a cylinder. SOLUTION: A seal portion 2 is provided between a glue chamber 3 having a nozzle opening 9 and a cylinder 4, penetrates the seal portion 2, a front end 8 a reaches the nozzle opening 9, and a rear end is a cylinder 4.
A valve stem 8 fixed to a piston 7 is provided. The seal portion 2 is provided with a valve stem passage 12 through which the valve stem 8 penetrates, and is provided with a gas supply port 15a and a gas exhaust port 15b which penetrate the main body 1 and the seal portion 2 and are connected to the valve stem penetration passage 12. ing. The air exhaust port 16 of the cylinder 4 has an electromagnetic directional switching valve 2
Compressed air is supplied from the air source 23 via the air inlet 2, and compressed air is also supplied from the air source 23 to the gas supply port 15 a via the variable throttle 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous fluid discharge nozzle for discharging a viscous fluid such as a paste, a paint, a sealing material and the like.

[0002]

2. Description of the Related Art A method of forming a box or bag by applying glue to a glue margin of a material for box making, bag making, and the like, bending the sheet, and bonding it at a predetermined position has been widely used. As a method of applying glue, there are a case where a roller is used and a case where a discharge nozzle is used. When applying glue intermittently, discharge nozzles are often used because discharge nozzles are easier to control.

[0003] The glue includes a commonly used aqueous glue generally called cold glue and a thermoplastic glue called hot melt. After the cold glue is applied, a drying time is required until the adhesive strength is generated. However, the adhesive strength is immediately generated when the hot melt is applied. Since the hot melt becomes solid at room temperature, it is heated and applied as a liquid from a discharge nozzle. However, a part of the liquid becomes a gas due to this heating, adheres to a piston or the like of an air cylinder for opening and closing the discharge nozzle, cools, and fixes the piston and the cylinder.

[0004] Discharge nozzles have been used which release such hot melt gas to the atmosphere to prevent the gas from going to the piston. FIG. 4 is a view showing an example of a discharge nozzle provided with an opening for discharging hot melt gas to the atmosphere.
The main body 1 of the discharge nozzle has a glue chamber 3 and a cylinder 4
And is divided into. The glue chamber 3 is provided with a glue chamber lid 5 having a nozzle opening 9 and a glue inlet 11, and the glue injected from the glue inlet 11 is discharged from the nozzle opening 9. A piston 7 is slidably fitted to the cylinder 4. The valve stem penetrates through the seal portion 2, the tip 8 a opens and closes the nozzle opening 9, and the rear end is fixed to the piston 7. A spring 10 is provided on the back surface of the piston 7 (on the side opposite to the valve rod 8), and presses the piston 7 to close the nozzle opening 9 by the tip 8a of the valve rod 8. An air supply port 16 is provided on the seal portion 2 side of the cylinder 4 to supply compressed air to move the piston, to separate the tip 8a of the valve rod 8 from the nozzle 9 and the opening 9, and to discharge the glue.

[0005] The seal portion 2 is provided at the center with a valve stem passage 12 through which the valve stem 8 penetrates, and is provided with an atmosphere opening port 30 connected to the valve stem passage 12 and communicating with the atmosphere. U-shaped seals 14 are provided at both ends of the valve stem passage 12 to prevent glue from flowing from the glue chamber 3 into the cylinder 4. When the valve rod 8 reciprocates, a small amount of liquid glue having a lubricating action infiltrates into the valve rod passage 12 and evaporates, and a part thereof is released from the atmosphere opening port 30.

[0006]

Even with such a structure in which the two seals and the air opening are provided between the two seals, the glue vaporized into the cylinder enters the cylinder while the discharge nozzle is used for a long time. In some cases, the piston adheres to the sliding surface of the piston to fix the piston to the cylinder. In particular, when the discharge nozzle is used horizontally or when the nozzle port is directed upward, the fixing is often performed in a relatively short time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a viscous fluid discharge nozzle for preventing a viscous fluid such as vaporized glue from entering a cylinder from a glue chamber. I do.

[0008]

In order to achieve the above object, according to the present invention, a glue chamber having a nozzle opening is provided.
A valve stem provided in the glue chamber, the tip of which opens and closes the nozzle opening, a cylinder in which a piston connected to the rear end of the valve stem slides, and a compressed air source for supplying compressed air to the cylinder; A seal portion provided between the glue chamber and the cylinder, the seal portion having a through passage through which the valve stem penetrates, and preventing conduction between the glue chamber and the cylinder through the through passage; The apparatus includes a seal portion having a gas flow path for supplying and discharging gas to a passage, and a gas supply portion for supplying gas to the gas flow path.

[0009] A seal portion is provided between the glue chamber and the cylinder, and the seal portion is provided with a through passage through which the valve stem passes. Seals are provided at both ends of the seal portion to seal the gap between the through passage and the valve stem. Further, a gas flow path for supplying and discharging gas to the through passage is provided, and gas is supplied to and discharged from the gas supply unit to the gas flow path. Therefore, even if the viscous fluid gas generated in the glue chamber passes through the seal provided between the seal portion and the valve rod and enters the through passage, the gas flowing through the through passage is released to the atmosphere.
This can prevent the viscous fluid gas from entering the cylinder.

[0010] In the second aspect of the present invention, the gas supply section includes an exhaust pipe for supplying exhaust from the cylinder.

The compressed air supplied to the cylinder is discharged after moving the piston. By supplying this exhaust gas to the gas passage, the viscous fluid gas in the through passage is released to the atmosphere. Although the exhaust gas supplied from the cylinder is intermittent, the amount of the gas of the viscous fluid permeating the through passage is small, so that it does not hinder the release to the atmosphere.

According to the third aspect of the present invention, the exhaust pipe is provided with a branch pipe for discharging a part of the exhaust gas to the atmosphere.

A branch is provided in the exhaust pipe, and a part of the exhaust is released to the atmosphere, thereby reducing the back pressure of the cylinder and quickly moving the piston.

In the invention according to claim 4, hot glue is supplied to the glue chamber.

Hot melt becomes liquid when heated,
Further, a part thereof is vaporized from liquid to become gas. Even if this gas enters the through passage of the valve stem, the gas is supplied to the gas flow path, so that the paste of the gas is released to the atmosphere and does not enter the cylinder.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. Although the embodiment will be described using glue as an example of the viscous fluid, the same applies to a case where a paint, a sealing material, or the like is used instead of the glue. The operation in the case where hot melt is used as the glue will be described, but the operation is substantially the same in the case of cold glue or the like.

FIG. 1 is a configuration diagram showing a glue discharge nozzle according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along line XX of FIG. The body 1 of the glue discharge nozzle has a cylindrical inside and a two-stage inner diameter at the center. In FIG. 1, the upper part is a cylinder 4 and the lower part is a glue chamber 3. A seal section 2 is provided to separate the glue chamber 3 and the cylinder 4. At the end of the glue chamber 3, a glue chamber lid 5 having a nozzle opening 9 is attached to the main body 1 with bolts. The glue chamber 3 is a chamber for holding paint when paint is used instead of glue, and for holding seal material when using seal material.

A cylinder lid 6 is screwed to the main body 1 at the end of the cylinder 4. The piston 7 is in the cylinder 4
The piston 7 penetrates the seal portion 2, passes through the glue chamber 3, and has a tip 8 a at a nozzle opening 9 provided in the glue chamber lid 5.
Is fixed. An O-ring 13 for sealing is provided on the outer periphery of the seal portion 2, and a valve stem passage 12 through which the valve stem 8 penetrates is provided at the center. Gas supply port 1 that passes through main body 1 and seal portion 2 to reach valve stem passage 12
5 a and a gas exhaust port 15 b are provided to supply and exhaust gas to the valve stem passage 12. Valve stem passage 12 of seal part 2
To seal the gap between the seal portion and the valve rod 8
A mold seal 14 is provided, and an O-ring is mounted to further enhance the effect of preventing conduction to the cylinder 4, and seals the conduction between the glue chamber 3 and the cylinder 4 by the valve stem passage 12.

A glue inlet 11 is provided in the glue chamber 3, and glue is supplied from a glue supply device (not shown) and is discharged from a nozzle opening 9. A spring 1 is provided between the cylinder lid 6 and the piston 7.
0 is provided, the piston 7 is pressed, and the tip 8 a of the valve rod 8 closes the nozzle opening 9. The strength of the spring 10 can be adjusted by rotating the cylinder lid 6. When the cylinder lid 6 is at an appropriate position, it is fixed at that position by the fixing nut 18. An air supply / discharge port 16 for supplying and discharging compressed air is provided on the seal portion 2 side of the cylinder 4, and an atmosphere opening port 17 for opening the inside of the cylinder 4 to the atmosphere is provided on the cylinder lid 6 side. The cylinder cover 6 is provided with an adjusting screw 19 for adjusting the stroke of the piston 7 and a fixing nut 20 for fixing the adjusting screw 19. A screw receiver 21 is provided on the piston 7 at a position facing the adjustment screw 19, and the interval S between the screw 7 and the adjustment screw 19 is the stroke of the piston 7.

The air supply / exhaust port 16 provided in the cylinder 4
Is connected to an electromagnetic directional control valve 22, and is operated by a switching signal from a control device (not shown). Electromagnetic directional switching valve 22
Is connected to an air source 23 that supplies compressed air. The gas supply port 15a is connected to an air source 23 via a variable throttle 24, and is supplied with compressed air adjusted to a predetermined pressure. Although the gas outlet 15b is open to the atmosphere, a silencer 25 is provided if necessary to mute the sound. Silencer 2
In the case where 5 is not provided, the opening end faces downward so that dust or the like does not enter.

Next, the operation will be described. Hot melt is used as the paste. Since the hot melt is solid at room temperature, it is heated and liquefied at the time of application, and is supplied from the glue inlet 11 by a pump. Air source 2 when electromagnetic directional control valve 22 is closed
The air supply / exhaust port 3 is connected to the air supply / exhaust port 16 such that the air supply / exhaust port 16 is open to the atmosphere when opened. When the electromagnetic directional control valve 22 is open, no compressed air is supplied to the cylinder 4 and the piston 7 is pressed by the spring 10 so that the tip 8a of the valve rod 8 closes the nozzle opening 9, so that no glue is discharged. When the electromagnetic directional control valve 22 is closed, the cylinder 4
Is compressed, and the piston 7 is pushed up, and the tip 8a of the valve rod 8 leaves the nozzle opening 9 to discharge the glue. Supply port 1
5a is supplied with compressed air from an air source 23 via a variable throttle 24, purges the inside of the valve stem passage 12 and discharges it to the atmosphere from a gas discharge port 15b. Even if the gas passes through the mold seal 14 and enters the valve stem passage 12, it is purged. Thus, the vaporized glue does not enter the cylinder 4 after passing through the O-ring and the U-shaped seal 14 on the cylinder side. The above is the case of hot melt supplied at a high temperature, but in the case of cold glue used at room temperature, even if the glue is vaporized, since the temperature is low and the vapor pressure is low, it is discharged from the gas exhaust port 15b. 4
The glue does not leak. In the case of cold glue, it is not necessary to supply air to the gas supply port 15a.

Next, a second embodiment will be described. FIG. 3 shows the configuration of the second embodiment. 1 and 2 represent the same members. In the first embodiment, the gas supply port 15 is used.
Although the supply of air to a is performed from the air source 23, the exhaust of the cylinder 4 is supplied in the second embodiment. For this purpose, the gas supply port 15a is connected to the atmospheric discharge port of the electromagnetic directional switching valve 22. A fixed aperture 26 may be provided on the way. In addition,
Since the back pressure of the cylinder 4 increases, it is preferable to provide a branch line 27 and discharge part of the exhaust gas to the atmosphere. As a result, the nozzle opening 9 can be quickly closed to prevent the stringing phenomenon at the end of the discharged glue. This branch line 27
Variable resistance 24 and silencer 25
Is provided. Others are the same as the first embodiment.

In the second embodiment, the air body supply port 15a
The supply of air is performed intermittently according to the operation of the electromagnetic directional switching valve 22. However, since the amount of vaporized paste entering the valve stem passage 12 is small, the vaporized paste sufficiently penetrated can be released to the atmosphere even with intermittent purging.

In the above embodiment, air is supplied to the gas supply port 15a, but any other gas such as nitrogen may be used. Further, although the piston 7 is driven by the spring 10 and the compressed air, the piston 7 may be driven only by the compressed air.
Further, it may be driven by a solenoid.

[0025]

As is clear from the above description, the present invention provides a valve stem from a glue chamber by supplying and discharging gas to and from a valve stem passage of a seal provided between the glue chamber and the cylinder. It is possible to reliably prevent the viscous fluid vaporized from entering the cylinder through the through passage. The air supplied to the valve stem passage can prevent the vaporized viscous fluid from entering the cylinder even if the exhaust gas is supplied from the cylinder. Thereby, the intervals of disassembly, inspection and cleaning can be lengthened.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a conventional glue discharge nozzle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Seal part 3 Glue chamber 4 Cylinder 5 Glue chamber lid 6 Cylinder lid 7 Piston 8 Valve rod 8a Tip 9 Nozzle opening 10 Spring 11 Glue inlet 12 Valve rod passage 13 O-ring 14 U-shaped seal 15a Gas supply port 15b Gas Discharge port 16 Air supply / exhaust port 19 Adjusting screw 21 Screw receiver 22 Electromagnetic directional switching valve 23 Air source 24 Variable throttle 25 Silencer 26 Fixed throttle 27 Branch line

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Isao Ono 2951-4, Ishikawacho, Hachioji-shi, Tokyo Inside Nireko Co., Ltd.

Claims (4)

[Claims] 1. A glue chamber having a nozzle opening, a valve stem provided in the glue chamber and having a tip opening and closing the nozzle opening,
A cylinder in which a piston connected to the rear end of the valve shaft slides, a compressed air source for supplying compressed air to the cylinder, and the valve shaft provided between the glue chamber and the cylinder are provided inside. A seal portion that has a through passage that penetrates, and is a seal portion that prevents the glue chamber and the cylinder from being electrically connected by the through passage, and has a gas flow passage that supplies and discharges gas to the through passage. A viscous fluid discharge nozzle, comprising: a gas supply unit that supplies gas to the gas flow path. 2. The viscous fluid discharge nozzle according to claim 1, wherein the gas supply unit includes an exhaust pipe that supplies exhaust gas from the cylinder. 3. The exhaust pipe is provided with a branch pipe for discharging a part of exhaust gas to the atmosphere.
A discharge nozzle for a viscous fluid as described above. 4. The glue discharge nozzle according to claim 1, wherein a hot melt is supplied to the glue chamber.