JPH0622461Y2 - Liquid discharge machine cooling structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a liquid ejecting machine for mixing and ejecting different kinds of liquids such as a base material and a curing agent in an adhesive, and in particular, for liquid mixing. The present invention relates to a mixing chamber structure of a liquid ejector suitable for removing heat of curing reaction.

(B) Conventional technology As a mechanism for mixing and discharging different kinds of liquids, for example,
There is an epoxy dispenser configured as shown in FIGS.

The side view of a part of FIG.
1 shows a plunger discharge mechanism for pressure-feeding different liquids before mixing, for example, a main component of an epoxy adhesive and a curing agent. The plunger discharge mechanism shown in FIG. 2 is installed according to the number of liquids to be mixed.

First, the plunger 1 is connected to the drive actuator 2 and moves up and down as indicated by the arrow. The vertical movement operation of the plunger 1 provides a pump function, and first sucks the liquid A in the tank 4 from the suction port 3. At this time, the liquid A already discharged from the discharge port 5
The check valve 6 prevents backflow so as not to inhale. The liquid A that has entered the measuring chamber (or cylinder) 7 is pushed out of the discharge hole 5 by the downward movement of the plunger 1 according to the principle of a water gun. At this time, tank 4
The check valve 8 prevents the liquid A from flowing back to the side.

In this way, according to the vertical movement of the plunger 1, a certain amount of the liquid A is pumped from the tank 4 toward the mixing chamber.

The sectional side view of FIG. 3 shows a mechanism for mixing and discharging different liquids before mixing which have been pressure-fed from the plunger discharge mechanism as shown in FIG.

For example, the main agent A and the curing agent B of the epoxy adhesive are
The liquid pressure-feeding means of FIG. 2 is pressure-fed to the discharge ports 10a and 10b provided in the nozzle block 9 by the tubes 9a and 9b, and is carried into the mixing chamber 12 formed in the housing 11 connected to the nozzle block 9, respectively. It The main agent A and the curing agent B carried into the mixing chamber 12 are mixed by the rotation of the mixing rotor 13 provided in the mixing chamber 12 and are discharged from the discharge port of the discharge valve 15 through the valve 14. Has become.

FIG. 4 shows another liquid mixing means. The nozzle block 9 is provided with discharge valves 9c and 9d, and the discharge valves 9c and 9d are provided.
Immediately after the mixing chamber 12 is provided. A mixing rotor 13 is arranged inside the mixing chamber 12, a discharge port 12a is provided in the lower part of the mixing chamber 12, and a very short flow passage 12b is provided between the discharge port 12a and the nozzle tip 12c. It is connected.

(C) Problems to be solved by the device When mixed type adhesives start to function as an adhesive by being mixed, in the case of the liquid ejector shown in FIG. That is, since the adhesive is discharged from the discharge valve 15 through the tube 14, the adhesive stays between the mixing chamber 12 and the discharge valve 15. Therefore, if it stays for a long time, there is a problem that before the ejection, it is hardened between the mixing chamber 12 and the ejection valve 15, and the ejection becomes impossible. Therefore, the range of the adhesive that can be used is limited depending on the distance from the mixing chamber 12 to the discharge valve 15.

Generally, in the case of the liquid discharger having the structure shown in FIG. 3, the use is limited to the adhesive having a slow curing speed. Further, for the reason described above, if the adhesive of mixed type is not discharged within the allowable time range, the adhesive is cured between the mixing chamber 12 and the discharge valve 15 and cannot be discharged. Therefore, in order to prevent such a state, the mixed adhesive is discharged after the liquid ejector is used,
Therefore, it is necessary to clean the inside of the discharge valve 15 each time, but in the case of the structure shown in FIG. 3, since the cleaning area is large, the adhesive discharge time and the cleaning time are long There is a drawback above.

Further, in the case of the liquid discharger having the structure shown in FIG. 4, the distance from the mixing chamber 12 for mixing the adhesive to the nozzle tip portion 12c is extremely short, so that the retention of the adhesive can be reduced as much as possible. It will be possible. Therefore, although the drawbacks such as the liquid ejector shown in FIG. 3 are solved, for example, when an adhesive having an extremely fast curing speed is used in a state where the installation environment temperature is high, the curing reaction heat during mixing radiates. Without this, the heat further accelerates the cure rate of the mixed adhesive. As a result, the adhesive is hardened between the mixing chamber 12 and the nozzle tip portion 12c, and the adhesive cannot be discharged.

Therefore, the applicant of the present invention has previously proposed a liquid ejector having a structure configured as shown in the side cross-sectional view of the main part of FIG. 5 in order to solve the above-mentioned drawbacks of the conventional example.

The liquid discharger shown in FIG. 5 has a different liquid A before mixing.
A nozzle block 9 for discharging B and B, a housing 11 connected to the nozzle block 9 and having a mixing chamber 12,
A mixing rotor 13 installed in the mixing chamber 12 for mixing the liquids A and B, and a discharge nozzle 15 for discharging the mixed liquids
And are provided. Further, on the outer circumference of the mixing chamber 12, a flow passage 16 for passing a cooling gas or liquid is provided. The flow passage 16 is provided with an inlet 16a and an outlet 16b, and the cooling gas or liquid enters through the inlet 16a and is discharged through the outlet 16b, and is configured to remove the curing reaction heat during liquid mixing. There is.

Therefore, in the liquid ejector shown in FIG. 5, the practical use range of the mixed type adhesive having a high curing speed can be greatly increased.

However, in the liquid discharger shown in FIG. 5 described above, in the case where a tip 17a of the tube 17 having a narrowed shape is attached to the tip of the discharge nozzle 15 and the adhesive is discharged to a fine portion, Since the tip portion 17a is squeezed, the flow velocity in the vicinity of the inner wall of the pipe becomes extremely slow, the mixed adhesive easily stays, and since this portion is not cooled, the reaction due to mixing In addition to the fact that the heat-cured adhesive is more likely to accumulate and the discharge port area is extremely small due to the structure, the tip 7a is apt to be blocked by the cured adhesive, and discharge is often impossible. There was a risk of doing it.

The purpose of this invention is to further improve the liquid discharger previously proposed by the applicant of this invention as shown in FIG.
It is to provide a liquid discharger with higher performance.

(D) Means for Solving the Problem In the cooling structure of the liquid discharger according to the present invention, a nozzle block for discharging different liquids before mixing and a mixing chamber connected to the nozzle block for mixing different liquids And a housing provided with a housing provided with a discharge nozzle for discharging the mixed liquid, in which a cooling member is arranged on the outer peripheral side of the mixing chamber, and the inner peripheral wall of the cooling member and the outer peripheral wall of the mixing chamber are A coolant flow path is formed in between, and an opening is formed on the wall surface of the cooling member in the discharge nozzle direction for rectifying the coolant from the flow path and leading it to the discharge nozzle tip. is there.

(E) Action By providing a cooling unit for cooling the space from the mixing chamber for mixing different liquids to the tip of the discharge nozzle, the heat of curing reaction at the time of mixing different liquids can be removed. By removing this curing reaction heat, the curing rate can be slowed down.

(F) Embodiment An embodiment of the cooling structure of the liquid discharger according to the present invention will be described with reference to the sectional view shown in FIG. The same parts as those in the conventional example described above are designated by the same reference numerals, and the description thereof will be omitted.

The upper part of the housing 11 where the mixing chamber 12 is provided has a flange part.
11a is provided. For cooling this flange 11a,
That is, in the case of this embodiment, the cooling air flow passage 11
b is provided.

A nut 18 for connecting the housing 11 to the nozzle block 9 is provided with a flange hooking portion 18a and a screw portion 18b.
Is screwed into a screw portion 9e provided on the nozzle block 9 to sandwich the flange portion 11a, and the upper portion of the mixing chamber 12 is crimped and attached to the nozzle block 9.

In this state, the flow passage 11b provided in the flange portion 11a and the flow passage 9f provided in the nozzle block 9 are connected.

In addition, the nut 18 has a clearance between the nut 18 and the outer peripheral wall surface forming the mixing chamber 12 below the flange hooking portion 18a.
Taking L1. This clearance L1 allows the cooling air discharged from the discharge port 18c provided in the flange portion 18a to pass through, and is discharged to the outside through the lower clearance L2. At this time, by appropriately adjusting the shape of the discharge port formed by the lower clearance L2, the cooling air discharged to the outside is rectified and reaches the discharge nozzle 15 and the tip portion 17a of the tube 17 having the tip throttle shape. , Cooling air flows all over.

Therefore, cooling can be performed from the mixing chamber 12 to the tip portion 17a of the tube 17.

By configuring as in the embodiment shown in FIG. 1, it is possible to cool the entire mixed adhesive from the outside. Therefore, the reaction heat generated when the liquids are mixed is removed, and the hardening promotion by the reaction heat is slowed down. Therefore, the accumulated adhesive, especially on the inner wall surface of the pipe, is reduced.

Further, in the case of the above embodiment, the mixing chamber 12 and the discharge nozzle 15
Also, since the portion of the tube 17 leading to the tip portion 17a is cooled from the outside, the adhesive curing reaction after mixing is likely to occur from the central portion of the tube. Therefore, the adhesive after mixing starts to gel near the center of the pipe, and the viscosity distribution of the adhesive inside the pipe is high in the central part and low in the outer peripheral part, that is, near the inner wall surface of the pipe. The viscosity difference increases in proportion to the time after mixing.

As for the flow velocity of the liquid in the pipe, it is well known that the flow velocity in the central part of the pipe is faster than the flow velocity in the vicinity of the inner wall surface of the pipe when the liquid viscosity is constant. Therefore, since the viscosity is high in the central part of the pipe where the flow velocity is fast, the flow velocity is slower than in the normal case, and conversely, the viscosity is low in the vicinity of the wall surface of the pipe, so the flow velocity is faster than in the normal case, and The flow velocity of the adhesive in the pipe becomes almost constant with a small difference between the central portion and the vicinity of the wall surface portion.

Regarding the increase in the viscosity difference in the pipe due to the progress of curing of the adhesive in proportion to the time after mixing, the pipe flow velocity distribution can be made constant by appropriately narrowing the pipe shape and adjusting the cooling temperature appropriately. Therefore, it is possible to reduce the accumulation of the further mixed adhesive on the inner wall surface of the pipe.

(G) Effect of the Invention According to the cooling structure of the liquid discharger according to the present invention, since the outer periphery from the mixing chamber to the tip of the discharge nozzle is configured to be cooled, the tip of the discharge port has a narrowed shape. Or
Alternatively, even if the distance from the mixing chamber to the discharge port is extended a little and the adhesive is discharged to a fine portion, the flow velocity distribution in the pipe for sending the adhesive can be made substantially constant. Therefore, the stagnant amount of the mixed adhesive on the inner wall surface of the pipe can be further reduced, and the tip of the discharge nozzle is less likely to be blocked by the hardened adhesive. The practical use range of mixed-type adhesives can be greatly increased.

[Brief description of drawings]

FIG. 1 is a sectional side view showing an embodiment of a cooling structure for a liquid discharger according to the present invention. 2 to 4 show a conventional example, and FIG. 2 is a side view in which a part of the plunger discharge mechanism is shown in section, and FIG.
FIG. 4 and FIG. 4 are sectional side views of the liquid discharger. FIG. 5 is a cross-sectional side view showing the liquid ejector previously proposed by the applicant of the present invention. 9: Nozzle block, 9f: Flow passage 11: Housing, 11b: Flow passage 12: Mixing chamber, 18: Nut L1, L2: Clearance

Claims (2)

[Scope of utility model registration request] 1. A nozzle block for discharging different liquids before mixing, a mixing chamber connected to the nozzle block for mixing different liquids, and a housing provided with a discharge nozzle for discharging the mixed liquid. In the liquid ejector, a cooling member is arranged on the outer peripheral side of the mixing chamber, and a coolant flow path is formed between the inner peripheral wall of the cooling member and the outer peripheral wall of the mixing chamber. In the cooling structure of the liquid ejector, an opening for rectifying the coolant from the flow path and leading it to the tip of the discharge nozzle is formed on the wall surface of the liquid discharger. 2. A cooling device for a liquid ejector according to claim 1, wherein the cooling member is constituted by a nut for attaching the housing having the mixing chamber to the nozzle block. Construction.