JPH06320101A - Gun for injecting powder - Google Patents

Abstract

PURPOSE:To enhance operational function by integrally providing a powder supply vessel to the body of a gun for injecting powder which is suitably used for powder slush molding and constituting the gun for injecting powder so as to surely perform fluidization of powder in the vessel. CONSTITUTION:In the case of powder slush molding wherein powder consisting of plastic is injected on the cavity face of a heated mold, when a trigger 17 is pulled to open a stop valve 11, compressed air flow directed to an injection port 4 is formed through an introduction port 6, an introduction chamber (b), the respective nozzles 24 and a straightening vane 25. A suction chamber (a) becomes a state of negative pressure by the compressed air flow and a normally closing valve 38 is opened. Since the normally closing valve 38 is so provided that the valve port 41 thereof is displaced at an outside air suction port 32 side higher than the surface (s) of a powder layer L in a storage chamber (d), outside air flows through an outside air flow chamber (c) from the outside air suction port 32. Powder (p) is fluidized by the outside air flow directed to the valve port 41 through the upper part of the surface (s) of the powder layer. Powder (p) is injected from the injection port 4 together with the outside air flow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a gun for powder injection, for example, a powder slush molding which is used to inject a plastic powder onto a cavity surface of a heated mold.

[0002]

2. Description of the Related Art In powder slush molding, it is necessary to fluidize the powder prior to the injection in order to make the injection of the powder uniform and smooth. Therefore, conventionally, a compressed air source for fluidizing the powder is connected to the tank containing the powder, and a connection tube for guiding the fluidizing powder to the gun is connected between the gun and the tank,
Further, a device is used in which a compressed air tube for sucking fluidized powder from the connection tube is connected to the gun.

[0003]

However, there is a problem in that the conventional device is large in size and the operability of the gun is poor because the connecting tube and the compressed air tube are connected to the gun.

In view of the above, an object of the present invention is to provide a simple powder injection gun having an improved operability by integrally providing a powder supply container on the gun body.

[0005]

A powder injection gun according to the present invention comprises a gun body having a tubular body and a powder supply container connected to one end of the tubular body. The body has an injection port at the other end, and a compressed air introduction port for producing a compressed air flow toward the injection port at the middle part, and between the introduction port and the powder supply container,
Each of the powder supply containers has a suction port for sucking the fluidized powder from the powder supply container side in a negative pressure state by the compressed air flow, and the powder supply container has a supply port at one end and a bottom wall at the other end. An inner container for accommodating powder, and an outer air circulation chamber around the outer periphery of the inner container that surrounds the inner container and has an outside air suction port on the input port side, and the inner container. An outer container body that respectively forms a storage chamber that temporarily stores powder on the outer surface side of the bottom wall of the body, and a negative pressure state in the suction chamber between the suction chamber and the outside air circulation chamber and the storage chamber. A normally-closed valve that is opened when the temperature becomes equal to, and a valve opening of the normally-closed valve is arranged so as to be displaced toward the outside air suction port side with respect to the surface of the powder layer formed in the storage chamber. .

[0006]

With the above-mentioned structure, only one compressed air tube is connected to the powder injection gun, and the gun has the powder supply container integrally, so that it has good operability and is simple. is there.

Furthermore, if the valve opening position of the normally closed valve is specified as described above, an external airflow is generated which goes above the powder layer surface of the storage chamber and goes to the valve opening. The powder is rolled up and flows, and then the fluidized powder flows into the suction chamber through the valve opening together with the outside airflow, and then is injected from the injection port together with the compressed air flow through the tubular body.

Since fluidization of the powder can be reliably realized in the powder supply container in this manner, no inconvenience occurs even if the powder fluidization tank is not provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a powder injection gun G used for powder slush molding has a gun body 2 having a cylindrical body 1 which is held substantially horizontally during use, and the cylindrical body. The powder supply container 3 is connected to one end of the powder supply container 1.

The cylindrical body 1 has an injection port 4 which is open outward at the other end, and a peripheral wall 5 at an axially intermediate portion.
An inlet 6 for compressed air is provided in the lower portion, and a suction chamber a is provided between the inlet 6 and the powder supply container 3.

In the tubular body 1, a grip 7 is provided on the outer surface of the intermediate portion in the axial direction of the tubular body 1 so as to extend downward.
One end of a tube 9 connected to the compressed air supply source is fitted to the connecting cylinder portion 8 existing on the lower end side of the grip 7. A passage 10 for compressed air is formed in the grip 7, and one end of the passage 10 communicates with the tube 9 and the other end communicates with the inlet 6.

An opening / closing valve 11 for opening / closing the passage 10 is provided in the grip 7, and the opening / closing valve 11 is constructed as follows. That is, a valve hole 12 is formed in the grip 7 so as to intersect with the passage 10, and the valve hole 12 has a large diameter hole 13 crossing the passage 10 and a small diameter hole extending from the large diameter hole 13 to the injection port 4 side. It consists of fourteen. Valve body 15 in large diameter hole 13
However, the valve rods 16 are slidably fitted in the small diameter holes 14, respectively. On the injection port 4 side of the grip 7, the trigger 1 is attached to the mounting plate 18 connected to the tubular body 1 and the grip 7.
One end of 7 is pivotally mounted via a support pin 19 _1, and the other end of the trigger 17 is connected to the tip of the valve rod 16 via a support pin 19 ₂ . The support pin 19 ₂ engages with an elongated hole (not shown) of the trigger 17. A compression spring 20 is loosely fitted to the valve rod 16 between the grip 7 and the trigger 17,
The elastic body of the compression spring 20 pulls the valve body 15 to close the passage 10.

In the cylindrical body 1, a compressed air hollow guide cylinder 21 is fitted on the inner surface of the intermediate portion in the axial direction. Both end surfaces of the hollow guide cylinder 21 are open, and the inside thereof communicates with the injection port 4 and the suction chamber a, respectively. A compressed air introduction chamber b is formed between the pair of flanges 22 present at both ends of the hollow guide cylinder 21 in cooperation with the peripheral wall 5 of the tubular body 1, and the introduction port 6 communicates with the introduction chamber b. . In the stepped wall portion 23 of the hollow guide cylinder 21, a plurality of small-diameter injection holes 24 are formed at equal intervals in the circumferential direction so that their center lines are converged between the hollow guide cylinder 21 and the injection port 4. Has been done.

A rectifying plate 25 is fitted in the cylindrical body 1 in the vicinity of the injection port 4. As shown in FIG. 2, the straightening plate 25 is formed by combining four plates 26 in a cross shape,
Each plate 26 is formed so that the thickness thereof gradually decreases from the end on the hollow guide cylinder 21 side toward the end on the injection port 4 side.

With this structure, the inlet 6
When a compressed air flow from each of the injection holes 24 to the injection port 4 is formed through the introduction chamber b, the suction chamber a is in a negative pressure state.

The powder supply container 3 comprises an inner body 27 and an outer body 28 surrounding the inner body 27, and these body 27, 28 extend upward from the tubular body 1.

The inner container 27 accommodates the powder p made of plastic, and has an upward insertion port 29 at one end.
Further, each has the bottom wall 30 at the other end, and a plurality of supply ports 31 are formed at the end of the bottom wall 30 on the side of the tubular body 1 as shown in FIG.

The outer body 28 is the inlet 2 of the inner body 27.
It has an outside air suction port 32 on the 9 side, an outside air circulation chamber c is formed around the outer periphery of the inner container 27, and a storage chamber d is formed on the outer surface side of the bottom wall 30 of the inner container 27.

The outer body 28 has a peripheral wall 33 and a bottom wall 34.
The extension surface of the outer surface is a tangential plane, and a connecting cylinder portion 35 communicating with the inside of the outer container 28 is provided.
It is attached to the cylindrical body 1 by being fitted on the outer peripheral surface of one end of the.

The inner body 27, as clearly shown in FIG.
A pair of support shafts 36 are projectingly provided on the outer peripheral surface in the vicinity of the input port 29, and both support shafts 36 are respectively engaged with a pair of notches 37 formed on the outer air intake port 32 side of the outer peripheral body 28 peripheral wall. Thus, the inner body 27 is swingably supported by the outer body 28.

Each of the support shafts 36 has, as an axis, a straight line that includes the center line of the inner body 27 and that intersects with the center line in a plane that intersects with the extension axis of the cylindrical body 1.

A normally closed valve 38 is provided between the suction chamber a and each partial region of the outside air circulation chamber c and the storage chamber d facing the suction chamber a. In this embodiment, the normally closed valve 38 is made of rubber in a disk shape and has four sections 40 formed by cross-shaped cuts 39, as shown in FIG.

In a normal state, each piece 40 extends straight without bending as shown by the solid line in FIG. The powder p supplied from each supply port 31 of the inner body 27 to the storage chamber d is prevented from flowing out to the suction chamber a by the normally closed valve 38, and thus the powder p is temporarily retained in the storage chamber d and thus the powder layer. Form L. The surface s of the powder layer L has a bottom wall 3 when the inner body 27 is in the non-swinging position of FIG.
It is almost at the same height as 0.

When the suction chamber a is in a negative pressure state, the normally closed valve 3
8 is opened by bending each segment 40 toward the suction chamber a side in an arc shape as shown by the chain line in FIG. 1 and FIGS. 3 and 4. As a result, the valve opening 41 surrounded by each section 40
However, the valve opening 41 is arranged so as to be displaced toward the outside air suction opening 32 side with respect to the surface s of the powder layer L formed in the storage chamber d.

With the above construction, only one compressed air tube 9 is connected to the powder injection gun G,
Further, since the gun G has the powder supply container 3 integrally, it has good operability and is simple.

In powder slush molding, when the grip 7 is grasped to make the tubular body 1 substantially horizontal and then the trigger 17 is pulled, the on-off valve 11 is opened and the passage 10 is electrically connected.
As shown by the arrow in FIG. 1, the introduction port 6, the introduction chamber b, each injection hole 24
A compressed air flow is formed toward the injection port 4 via the straightening plate 25, and the compressed air flow is ejected from the injection port 4 to the outside.

Since the suction chamber a is brought into a negative pressure state by this compressed air flow, the normally closed valve 38 is opened. In this case, since the position of the valve opening 41 of the normally closed valve 38 is specified as described above, as shown by the arrows in FIGS. 1 and 3, the air flows from the outside air intake port 32 through the outside air circulation chamber c to the powder layer L. An outside airflow is generated which goes above the surface s toward the valve opening 41, and the powder p on the surface s side in the powder layer L is rolled up and flows by the outside airflow, and the fluidized powder p is then discharged together with the outside airflow to the valve opening
1 and flows into the suction chamber a, and then is injected together with the compressed air flow through the inside of the cylindrical body 1 to the outside from the injection port 4.

When the gun G does not have the current plate 25,
The powder injection pattern on the cavity surface of the mold becomes an annular shape, and a circular powder non-adhesion region is formed around the center of the pattern.
With 5, the powder injection pattern becomes circular,
The powder non-adhesion area as described above does not occur.

In the powder injection work, the gun G
May be swung so that the injection port 4 side may move up and down somewhat, but at this time, the inner container 27 swings and the surface of the powder p inside thereof is kept substantially horizontal, so that the powder p is inserted into the injection port 29. It is prevented from flowing out from.

[0030]

According to the present invention, a powder having a gun body and a powder supply container integrated with the gun body, which is capable of reliably fluidizing the powder in the powder supply container, has good operability and is simple and simple. An injection gun can be provided.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of a powder injection gun.

FIG. 2 is an end view taken along line 2-2 of FIG.

FIG. 3 is a fragmentary plan view corresponding to a view taken along the line 3-3 of FIG.

FIG. 4 is a front view of a normally closed valve in which one section is bent.

[Explanation of symbols]

 1 Tubular Body 2 Gun Body 3 Powder Supply Container 4 Injection Port 27 Inner Body 28 Outer Body 29 Input Port 30 Bottom Wall 31 Supply Port 32 Outside Air Suction Port 38 Normally Closed Valve 41 Suction Chamber c Outside Air Flow Chamber d Reservoir p Powder s Surface L Powder layer

Claims (1)

[Claims] 1. A gun body (2) having a tubular body (1).
And a powder supply container (3) connected to one end of the tubular body (1). The tubular body (1) has an injection port (4) at the other end and an intermediate portion. In the injection port (4)
A compressed air inlet (6) for generating a compressed air flow toward the space between the inlet (6) and the powder supply container (3) and a negative pressure state due to the compressed air flow. The powder supply container (3) is provided with suction chambers (a) for sucking the fluidized powder (p) from the container (3) side, and the powder supply container (3) has a charging port (29) at one end and a bottom wall (30) at the other end. ) Each having a supply port (31) in each of which the powder (p) is housed, and an outside air suction port (32) surrounding the inner container (27) and at the input port (29) side. ) Having an outside air circulation chamber (c) around the outer periphery of the inner body (27), and the inner body (27).
Outer chambers (28) respectively forming storage chambers (d) for temporarily accumulating powder (p) on the outer surface side of the bottom wall (30) of the above, the suction chamber (a) and the outside air circulation chamber ( A normally closed valve (38) which is opened when the suction chamber (a) is in a negative pressure state is provided between the c) and the storage chamber (d), and the valve opening (38) of the normally closed valve (38) is provided. 41) The gun for powder injection, wherein 41) is arranged by displacing it toward the outside air intake port (32) side with respect to the surface (s) of the powder layer (L) formed in the storage chamber (d).