JPH0716532A - Method for holding temperature of heating fluid emitted from nozzle and device therefor - Google Patents

Abstract

PURPOSE:To stabilize the emitting flow rate and emitting state of a fluid by keeping the temp. of the heated fluid immediately after emitted from a nozzle constant. CONSTITUTION:The outer periphery of a nozzle 3 is almost coaxially surrounded by a hood 5 and the passing hole 8 of the emitted fluid from the nozzle 3 is bored in the hood 5 and the inner surface of the hood 5 is formed as a mirror surface and a heat insulating plate is provided to the outside of the hood 5 and the attaching part of the hood 5 is extended up to the outside surface of a gun body to enhance heat insulating effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat retaining method for a heated fluid immediately after being discharged from a nozzle and a heat retaining apparatus for the same.
It should be noted that the term “ejection” also includes ejection spray, and the nozzle includes a contact-type coating nozzle for the object to be coated.

[0002]

2. Description of the Related Art Conventionally, a normal temperature liquid or pasty adhesive or coating agent is provided with a gun in order to maintain an appropriate viscosity of the agent in the operation of the gun or the passage inside the nozzle. Prior to feeding into, the fluids have been raised above their required temperatures and heated in anticipation of the decreasing temperatures. At times, for thermoplastic resins and solders that are solid at room temperature, those that have been heated and melted above their melting points are further heated independently in the gun or nozzle, and the temperature is higher than the heating temperature at the time of supply. Was set to.

As described above, it is not only uneconomical to heat a liquid or a melted material more than necessary, but it also causes deterioration of the material or carbonization. Measures to prevent them have been taken for some time. For example, JP-A-62-17656
As shown in the drawing disclosed in Japanese Patent Publication No. 8 or FIG.
Inside the intermediate adapter (52) provided between the gun body (51) and the nozzle (53), a fluid passageway (57) branched from the supply passageway (56) for supplying the discharge fluid to the valve chamber is provided. The temperature from the valve (58) to the nozzle (53) is made equal to the discharge fluid temperature by passing the fluid having the same temperature as the above, or another embodiment disclosed in the publication, that is, FIG. So that the spiral tube (6) is attached to the outside of the intermediate adapter (62) and its nozzle (63).
Various measures have been taken by winding 4) to measure the temperature of the discharged fluid to be the same. However, in spraying paints and the like, a large amount of air is supplied and exhausted to collect excess mist in the booth, so an air flow of about 1 m / sec flows around the gun and nozzle. Will lower their temperature. Also,
The tip of the nozzle is smaller and sharper (93 in FIG. 13) in order to reduce the adhesion of the discharge fluid, and there is also a further advanced tube-shaped (103 in FIG. 14). In addition, it lowers the temperature during discharge,
That is, it has become a cause of stringing by increasing the viscosity.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the structure as shown in FIG. 9 disclosed by Japanese Patent No. 76568, the outside of the essential nozzle (53) is still exposed to the atmosphere, so that the temperature drop is unavoidable, and as shown in FIG. So that the nozzle (63)
In the case where the spiral tube (64) is wound on the outer side, the temperature drop of the nozzle is smaller than that described above, but there is a problem that it is extremely difficult to attach and detach the nozzle.
Further, as described in the section of the above-mentioned related art, when the nozzle is miniaturized, the invention according to the above-mentioned publication cannot be applied. For example, when the melt is discharged from the nozzle, the fluid near the outlet of the nozzle hole is cooled by the air flowing around the outer circumference of the melt, which increases the viscosity and changes the discharge amount of the melt. At the time of disconnection, the thread is pulled, and the fluid adhering to the tip of the nozzle also aggregates into a bead, which cools and sticks. Then, when the ejection is restarted, the adhered agglomerated balls are pushed out (Ld in FIG. 11), and further, the thread (Lf), that is, the tail is pulled and falls. They are shown in FIG.
As can be seen from the above, the so-called hook (Lh) is used to stain the coated surface. The subject of the present invention is regardless of the size of the nozzle.
For all types of nozzles, and simply, to keep the temperature of the nozzles and the heating fluid discharged from them constant.

[0005]

SUMMARY OF THE INVENTION The gist of the present invention is to keep the temperature of the nozzle and its surroundings by insulating the outside of the nozzle and the like from the outside with a hood, and by accumulating thermal energy radiated from the nozzle and the like. A method for holding the temperature of the heated fluid to be discharged and a heat retainer for the method. The method of the present invention will be described. See FIG. The fluid kept at an appropriate temperature is discharged from the nozzle hole through the air (A
It is discharged (Le) during r). With respect to the temperature of the air (Ar), the thermal energy emitted from the nozzle (3) and the gun body (1) is surrounded by the hood (5),
There is little emission into the atmosphere outside the hood (5). In addition, since a hole (8) having a size that does not interfere with the discharge flow (Le) is formed in a part of the hood that hits the discharge flow path from the nozzle (3), the discharge flow (Le) causes ,
Since the hole (8) will be almost closed, this also reduces the dissipation of heat energy into the atmosphere. Therefore, the thermal energy from the nozzle (3) and the discharge flow (Le) is relatively efficiently accumulated in the air (Ar) inside the hood (5). That is, the temperature close to the temperature of the fluid to be discharged, that is, an appropriate temperature is maintained.

If the hood (5) is made of metal and a relatively thick plate is used, the body (1) in contact with the hood (1)
A large amount of heat from the inside of the hood (5) is transmitted to increase the temperature of the hood (5), and heat is conducted to the air (Ar) inside the hood (5) to further raise the temperature of the air. The heat dissipation of the nozzle (3) can be suppressed. Furthermore, if the outside of the hood (5) is covered with a heat insulating material, the effect will be improved. Therefore, the viscosity of the fluid to be discharged is also maintained constant, so that the fluid is discharged stably. Further, it is possible to prevent the occurrence of the stringing phenomenon and the hook phenomenon when the discharge is stopped or restarted. The above has described the case of discharging a heating fluid or the like. However, the invention applies even if it is a jet. This is because, in the case of jetting, the temperature of the fluid decreases due to the adiabatic expansion of air. In the case of airless spray, 5m from the opening of the nozzle.
Since it is in a liquid state without being atomized between m and 10 mm, the temperature of the nozzle and the vicinity thereof is kept constant as in the case of the above ejection, and stable ejection is performed.

Next, a warmer based on the above method will be described. See FIG. The nozzle (13) is attached to the tip of the gum body (11). A hood (15) is mounted on the same axis as the axis of the nozzle (13) with a space (16). The hood (15)
The base portion (17) of the is a nozzle mounting surface (11b) of the Gunbody
The upper side is fixed by a screw (19), and the other side, that is, the discharge side of the fluid on the axis line, has an opening (18) on the flow path.

[0008]

The operation of the gun nozzle provided with the above-mentioned heat retaining device will be described. Discharge holes (1 inside the nozzle (13)
4) The thermal energy of the liquid (L) passing through the inside and having a proper viscosity or temperature for discharging is conducted into the body of the nozzle (13), and the air (Ar) coming in contact with it from the surface thereof.
Conduct to. The air is surrounded by a hood (15),
Since the thermal conductivity of the air (Ar) inside is extremely low, the thermal energy that follows is also accumulated in the air and the temperature rises. If the hood (15) is heat-insulating, the amount of heat radiated to the outside will be small. Therefore, the temperature of the air rises to near the temperature of the liquid and is kept constant. Therefore, the temperature of the liquid (L) passing through the discharge hole (14) is reduced by a small amount, a constant temperature close to that temperature is maintained, and the liquid is stably discharged.

[0009]

【Example】

First Embodiment See FIG. The base or mounting plate (17) of the hood (15) is screwed to the tip end surface (11b) of the gun body (11) in substantially the same axis as the axis of the nozzle (13) attached to the tip end of the gun body (11). (1
9), and the other part of the hood (15) is provided with a passage for the discharge flow (Le) from the nozzle (13) port. Alternatively, as a mounting method, the outer peripheral edge of the mounting plate (17) may be extended, bent upward at a right angle (15A), and mounted along the side surface of the Gunbody (11). The reason is that they are aligned with each other and some of the heat is kept on the gum body (11).

When the outer circumference of the nozzle is relatively large, such as the spiral type coating nozzle (23) shown in FIG. 4, the hood (25) surrounding it is naturally large and the space (26 ) Is opened, the hood (25) is further extended upward, and the inside thereof is attached to the outside surface of the gum body (21). Alternatively, a space (26A) with the side surface is opened and attached. At this time, the hood is made of a metal having a high thermal conductivity, and a spacer (28) having a high thermal conductivity is also interposed between the hood (25) and the gun body (21) to attach the heat of the gun body (21) to the hood (25). Tell them the whole thing and try to raise it to a higher temperature.

Second Embodiment See also FIG. Hood (2
The inner surface of 5) is a mirror surface (25F) or a mirror surface plate (27) attached. Thereby, the heat rays are reflected and the heat radiation to the outside is blocked. In addition, it goes without saying that if a heat insulating material, that is, a plate (27) made of silicon resin, fluorine resin or the like, or ceramic is attached to the outer side and coated, the effect is further enhanced. This can be said to be a method in which the heat insulation effect of air and heat reflection are successfully combined.

Third Embodiment In the above-mentioned embodiment, the heat dissipation of the nozzle and its mounting gun is prevented. In this embodiment, the heat of the block (34) which is the mounting body of the gun body (31) is measured. It also prevents radiation. That is, as shown in FIG. 5, the hood (35) of the nozzle portion is extended and fixed onto the block (34).

Fourth Embodiment Please refer to FIG. It has two hoods. The first hood (45) is made of a metal having a high thermal conductivity and is attached with the space (46) in the gum body (41) opened, and the inner surface thereof is a mirror surface (like the second embodiment mentioned above). 45F or 47)
Furthermore, a space (4) is provided outside the hood (45).
8) is provided and a second hood (49), that is, a heat insulating one is attached. The action is that the nozzle (4
Heat rays from 3) are reflected on the mirror surface, and at the same time Gambodi (4
1) conducts heat from the hood (45) to raise the temperature of the hood (45) itself and conducts heat to the air inside the hood (45) to raise its temperature. Insulated by the air in the space (48) surrounded by the heat insulating hood (49), heat dissipation to the outside air is minimized,
The temperature of the tip portion of the nozzle (43) is kept higher and stable by the total action of these.

Fifth Embodiment See FIGS. 7 and 8. A long-angled hood (75) is attached to a contact type slot nozzle (73) that contacts the surface of the object to be coated.

[0015]

As a result of the experiment by attaching the hood to the gun and the nozzle according to the present invention, when the inlet temperature of the supply liquid to the gun is set to 60 ° C, the temperature drop in the nozzle portion is within the range of 2 ° C. You can now stop. For example, the handling material is EV of hot melt adhesive.
When the gun nozzle and its hood shown in the fourth embodiment (FIG. 5) are used as A, the heating temperature of the supplied hot melt is 180 ° inside the block (31).
When set to C, the temperature at the tip of the nozzle (33) is about 17
It was 3 ° C, and the temperature drop was only 7 ° C. In the conventional case, the temperature of the block (34) is set to about 195 ° C in order to keep 173 ° C in the nozzle portion, so that the temperature drop of about 20 ° C is prevented. . Further, by maintaining a constant temperature at the tip of the nozzle, the accuracy of the discharge amount can be improved. For example, at 200 cycles per minute, intermittent discharge of 60 mg per cycle was repeated for a total of 8 hours by repeating a pause of 5 minutes for 25 minutes. When the conventional discharge accuracy was ± 10%, it was ± 1%. It was possible to put it in the range of.

The above-mentioned 12% reduction in electricity consumption is extremely large in terms of work cost reduction. Not only that, but as described above, if the supply temperature is raised by 12% or more from the proper discharge temperature, the resin sometimes deteriorates or carbonizes, which can be prevented in advance. Further, by keeping the temperature of the air inside the hood as described above, the temperature of the melt discharged from the nozzle can be kept constant, so that the discharge amount is stabilized. Furthermore, it is possible to prevent the occurrence of stringing or hooking when the discharge is interrupted or restarted. Further, by covering the nozzle, the gum body, and the like with a hood, it is inevitable to prevent burns and improve work safety.
Also, when installing a sensor etc. near the gun nozzle,
It also offers many secondary advantages, such as eliminating the need to use expensive heat-resistant sensors.

[Brief description of drawings]

FIG. 1 is an operation explanatory view of a nozzle having a hood attached to a nozzle according to the method of the present invention.

FIG. 2 is a side sectional view showing how to attach the heat retaining device in the first embodiment according to the present invention.

FIG. 3 is a sectional view taken along the line AA in the upper diagram.

FIG. 4 is a side cross-sectional view of the warmer according to the second embodiment of the present invention in which the inner surface of the hood is a mirror surface.

FIG. 5 is a side view of a warmer according to a third embodiment of the present invention in which a mounting portion of a hood is extended to cover an outer surface of a gun body and a mounting block of the gun body is covered with a heat insulating plate.

FIG. 6 is a side view of a warmer according to a fourth embodiment of the present invention, which has a double hood.

FIG. 7 is a side sectional view of a warmer according to a fifth embodiment of the present invention in which a hood is attached to a slot nozzle.

FIG. 8 is a top view C-view.

FIG. 9 shows a first example of a conventional nozzle heating type.

FIG. 10 shows a second example of a conventional nozzle heating type.

FIG. 11 is a state diagram of stringing when a heated melt is discharged from a conventional nozzle.

FIG. 12 is a state explanatory view of what is called a hook that is generated when a material discharged from a conventional nozzle is applied onto an object to be coated.

FIG. 13 is a side view of a conventional small nozzle.

FIG. 14 is a side view of a conventional thin tubular nozzle.

[Explanation of symbols]

3,13 nozzles 5,15,2
5 Hood 8,18 Discharge flow passage hole 27 Mirror surface Le Discharge flow

Claims (5)

[Claims] 1. Heating for discharging from the nozzle (3) by surrounding at least the outer periphery of the nozzle (3) for discharging the heated fluid with a hood (5) having a passage (8) for discharging them. A method for retaining heat of a heating fluid ejected from a nozzle, characterized in that the fluid (Le) is ejected while retaining the temperature. 2. A method for retaining heat of a heating fluid discharged from a nozzle according to claim 1, wherein the discharging is jetting. 3. A hood (15) having a space (16) at least around the outside of the nozzle (13) and having a passage hole (18) for heating fluid discharged from the nozzle (13). Is attached to at least the periphery of the nozzle. 4. A heat retaining device for heating fluid discharged from a nozzle according to claim 3, wherein the discharging is jetting. 5. A heat retaining device for heating fluid discharged from a nozzle according to claim 3, wherein the inner surface of the hood (25) is a mirror surface (27).