JPH0352322B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The applicant's earlier application P3331840.9 (German Patent No. a composite nozzle for merging and guiding in a casing; a component supply conduit guided into the casing; a casing bore arranged in the casing and having a coaxial outlet passage at its end face; at least one needle sleeve guided coaxially in the casing bore; a nozzle needle guided coaxially in the needle sleeve; between the surrounding wall of the casing bore and the needle sleeve as well as between the needle sleeve and the nozzle. an inner chamber arranged between the needles and to which a component supply conduit is connected in each case, in which case in the closed state of the nozzle the nozzle needle cooperates with the needle sleeve and the needle The outer end surface of the sleeve cooperates with the inner end surface of the casing hole to form a sealing seat, whereas in the nozzle open state, the coaxial nozzle opening of the needle sleeve is released from the nozzle needle. , a nozzle opening is formed between the outer end surface of the needle sleeve and the inner end surface of the casing hole, and the nozzle needle further has a coaxial pin, and the cross-sectional shape and dimensions of this pin are similar to that of the needle. The cross-sectional shape and dimensions of the nozzle opening of the sleeve and the outlet passage are matched, and in the closed state the outlet passage is filled up to the outlet by this pin, and the nozzle needle and the other end of the needle sleeve are A forced control device is attached.

In such a type of compound nozzle, one component is supplied through a central opening and the other component is supplied through a concentric chain of rings.

Since a component under pressure acts around the closed ring-shaped nozzle gap, in order to prevent leakage in the closed state,
The sealing surface provided for the seal seat must be machined with extreme precision. Even if the needle sleeve is only slightly deformed, the sealing surface will warp and the sealing properties of the seal seat will be impaired. A further disadvantage of this embodiment is that a separate needle sleeve must be provided for each additional component beyond the two reaction components.

Therefore, the object of the present invention is to improve the composite nozzle of the type mentioned at the beginning to prevent leakage caused by deformation of the sealing surface, and to prevent leakage from occurring when three or more components are supplied separately. Another objective is to ensure that only a single needle sleeve is required or to be able to reduce the number of needle sleeves required.

A composite nozzle according to the invention proposed to solve this problem is a composite nozzle for guiding the merging of at least two fluid reaction components for producing a fluid reaction mixture that reacts to produce plastics, in particular foam plastics. a nozzle casing; located within the nozzle casing and limited by a sealing surface that itself tapers toward the axial outlet passage; a guide hole which is closed by an inserted insert; a nozzle needle which is guided in an axial bore of the insert and has a pin which fills the outlet passage in the closed position and which is at the same time forcefully controllable; It consists of a needle sleeve that is slidably guided in the area between the body and the sealing surface; an inner chamber that is provided within the needle sleeve and is penetrated by the nozzle needle, in which case: the interior chamber is connected to the component supply conduit, the needle sleeve has a base extending toward the outlet passageway and having an opening aligned with the outlet passageway, the outer surface of the base portion comprising: is designed as a sealing surface and at the same time forms a sealing seat in cooperation with the sealing surface of the casing bore in the closed state, and is provided with a supply conduit for at least one further flowable component; The opening of this supply conduit is arranged within the area of the sealing surface of the housing bore and is closed in the closed position by the sealing surface of the needle sleeve.

In such a compound nozzle, the risk of leakage is at least considerably reduced, since in the closed position the component pressure does not act around the sealing seat, but only in the area of the opening. Since these openings are relatively small, leakage will not occur unless the sealing surfaces are significantly deformed.

In a mixing device already proposed in the European patent application (publication number: 0090257), the component supply conduit opens into the gap formed between the casing and the insert (hollow piston). In this case, a discharge piston is passed through the center of the insert. The insert itself undergoes a rotational movement. Said gap thus performs the function of a shear gap and forms a mixing chamber. The mixing of the reaction components in such gaps already poses cleaning problems in itself.

In contrast, in the composite nozzle according to the invention only one reaction component is introduced into the gap, so that the mixing process takes place outside the gap. No problems arise if further components which do not react with the first-mentioned components and which do not react with each other can also be introduced into this gap.

According to one embodiment of the invention, a plurality of openings are assigned to the supply conduit. These openings are advantageously evenly distributed around the central axis of the compound nozzle.

According to a first embodiment of the invention, the opening or openings are radially oriented.

According to this measure, each radially supplied component, depending on its inherent energy, is either injected into the centrally flowing component or surrounded by it.

According to another embodiment of the invention, the opening or openings are oriented tangentially. According to this measure, the central component flow is surrounded by
In this case, the boundary layer located between the two component streams is advantageously brought into relative motion.

Furthermore, it is also possible for the opening or openings to occupy intermediate positions between radial and tangential directions.

The strength of the induced effect depends on whether the radial or tangential component of the orientation is predominant.

Further flow effects can be obtained if the openings are oriented obliquely rather than perpendicularly to the central axis.

Depending on the respective physical properties of each component, these different embodiments can be utilized by first finding out the appropriate orientation of the feed conduit opening by experiment and then using it in practice.

According to a particular embodiment of the invention, a supply conduit for the additional component is provided, the opening of which faces into the guide hole of the nozzle needle, the nozzle needle having a step. This step is used as a control edge by freeing the opening from the step in the open position of the nozzle needle and sealing the opening with a larger diameter shaft section in the closed position.

By taking such measures it is possible to add at least one additional component to the main component guided through the central part, which may be particularly advantageous under certain conditions. be.

In this case, the composite nozzle is provided with an alternative embodiment; in the first embodiment, the guide hole for the nozzle needle is arranged in the insert, whereas in the second embodiment, the guide hole for the nozzle needle is arranged in the insert. In the example, a guide hole is provided in the needle sleeve.

In both embodiments, the flow of additional components is released or interrupted by a step in the nozzle needle. In this case, it is clear that each supply conduit for a plurality of additional components can be arranged in the same way, and it is advantageous if their respective openings are arranged at equal mutual spacing. Furthermore, it is also possible to assign several openings to one supply conduit.

The main component of the plurality of main components that is matched with the additional component is guided through the interior chamber in the needle sleeve. This is because a mixture of the main component and the additional component remains in this interior chamber after each working cycle.

According to a further embodiment of the invention, a compound nozzle is combined with a forming tool via a stop guide and a corresponding connecting element.

The advantage of this embodiment is that the compound nozzle, which is otherwise stationary, can be brought into abutment against a forming tool that is moved periodically along it, for example on a turntable. . In this case, it is advantageous if a control device known per se is provided, which only initiates the mixing process when the forming tool is closed and the composite nozzle is sealed. For example, a slide guide is used as the contact guide, and the contact operation itself can be carried out, for example, by means of an associated hydraulic drive.

In this embodiment, a stabilization chamber is provided in the surrounding wall of the forming tool, located in front of the mold cavity, and the inlet opening of the stabilization chamber is aligned with the outlet opening of the nozzle at the connection position of the compound nozzle. Advantageously, the molding tool is closed by means of a closing slide integrated into the surrounding wall of the forming tool.

If such measures are taken, the outlet opening of the compound nozzle will be sealed when the compound nozzle is connected to the forming tool. The closing slide can be configured as an opening/closing slide. However, this closing slide can also open against the initial stress under the pressure generated under the mixture and can also be designed as an ejector for the residual mixture reacted in the stability chamber. Furthermore, the closing slide can also be constructed in such a way that, for example, a stability chamber is used as a guide. The stroke of the closing slide can be adjusted, for example, by means of an adjustable stop. It is advantageous if the axis of the closing slide is aligned with the axis of the compound nozzle, but it may also have any other orientation, in particular an arrangement in which these two axes are at right angles to each other. It is possible. The closing slide can be operated hydraulically or mechanically and is preferably automatically controllable.

The invention will now be explained in more detail with reference to an exemplary embodiment shown in the accompanying drawing: In the figure, a composite nozzle according to the invention is shown as a four-component embodiment, with a forming tool shown schematically in section. are combined. Guide holes 2 to 2' are arranged within the nozzle casing 1. This guide hole 2 or 2' is delimited by a sealing surface 4 converging towards the axial outlet channel 3, while it is closed by an insert 5 located in a closure cover 48. A guide hole 6 for a nozzle needle 7 is provided in the insert 5 . This guide hole 6 has at its rear end a piston 9 which can be alternately loaded and which is guided in a cylinder chamber 8 , the cylinder chamber 8 and the piston 9 forming two parts in a forced control device 10 of the nozzle needle 7 . has been completed. At its front end, the nozzle needle 7 has a pin 11 which completely fills the outlet passage 3 in the closed state and thus provides a cleaning aid for draining the mixture remaining in the outlet passage 3. Also useful as a tool. A slidable needle sleeve 12 is provided between the sealing surface 4 and the insert 5. The rear end of this sleeve is configured as an alternatingly negative hydraulic piston 14 guided in a hydraulic cylinder 13 , cylinder 13 and piston 14 being both components of a force control device 15 . The front end of the needle sleeve 12 has a base 16, the outer surface of which is designed as a sealing surface 17, which cooperates with the sealing surface 4 to form a sealing seat 18 in the closed position. This base part 16 has an axial opening 19 adapted to the outlet passage 3. The stroke of the needle sleeve 12 and thus the gap width between the two sealing surfaces 4, 17 can be adjusted by means of an axially displaceable insert 5. To adjust the stroke of the nozzle needle 7, an adjusting screw 20, which is mounted in the insert 5, is used. Inside the needle sleeve 12 there is an internal chamber 22 connected to a supply conduit 21 for component A;
In the open position of the nozzle needle 7, component A flows out of this interior chamber 22 via the opening 19. The supply conduits 23 and 24 for components B and D have openings 25 and 26, respectively, through the sealing surface 4 and are diagonally opposite each other. The supply conduit 27 for component C runs through the closure cover 48 and the insert 5 to the end of the insert facing the interior chamber 22 . However, the opening 28 of this supply conduit 27 forms a guide hole 6 for the nozzle needle 7.
facing inward. The nozzle needle 7 has a step 29 which acts as a control edge on the edge of the large-diameter shaft section 30 so as to open the opening 28 of the supply conduit 27 in the open position. , and the component C flows into the inner chamber 22 through the ring-shaped gap 32 formed between the guide hole 6 and the shaft section 31 with a small diameter, and is arranged so that it first merges with the component A. . This additional component C then reaches into the opening 19 together with component A and is passed further into the outlet passage 3 where it is mixed with component B.
and C. When the nozzle needle 7 is closed, the step 29 moves onto the opening 28 and the large diameter shaft section 30 closes this opening 28 .

This composite nozzle is combined with a forming tool 33. The forming tool 33 consists of two mold halves 34, 3.
5, forming a mold cavity 36. The mold half 34 on the side facing the compound nozzle has a centering recess 37 that fits into the centering addition 38 of the compound nozzle. This forming tool 33 is fixed in position, whereas the compound nozzle is movable towards the forming tool 33 inside the schematically illustrated abutment guides 39, 40. The centering addition 38 and the centering notch 37 have matching surfaces 41, 42 that match in the closed state. A stabilization chamber 43 is provided in the other mold half 35 and extends axially towards the centering recess 37 .
This stability chamber 43 also serves as a guide for a closing slide 44, to which a hydraulic drive 45 and an adjustable stop 46 are assigned. In this embodiment, the closing slider 44 only has an opening/closing function, but it can also be used as an ejector for removing the residual mixture hardening in the stabilization chamber 43. This stability chamber 43 is
If the composite nozzle occupies a detached position (not shown), it is completely filled by the closing slide 44 at the earliest until it abuts the forming tool 33, in which position the composite nozzle remains open until the nozzle process is started. The outlet opening 3 is sealed.
In the abutment position of the compound nozzle, the outlet opening 3 and the inlet opening 47 of the stability chamber 43 are directly adjacent to each other and lie in the same axis.

[Brief explanation of drawings]

FIG. 1 shows the compound nozzle according to the invention in its open position, and FIG. 2 shows its closed position. 1... Nozzle casing, 2, 2'... Guide hole,
3... Outlet passage, 4, 17... Seal surface, 5... Insert, 7... Nozzle needle, 8...
...Cylinder chamber, 9,14...Piston, 10,1
5... Forced control device, 11... Pin, 12... Needle sleeve, 13... Hydraulic cylinder, 16...
...Base, 18...Seal seat, 19, 25, 2
6, 28...opening, 20...adjustment screw, 21,
23, 24, 27... Supply conduit, 22... Inner chamber,
29...Step part, 30, 31...Shaft division, 3
2...Ring-shaped gap, 33...Forming tool, 34,
35...Mold half body, 36...Mold hollow chamber, 37...
Centering notch, 38... Centering addition part, 39, 40
... Contact guide, 41, 42 ... Matching surface, 43 ...
Stability chamber, 44... Closing slider, 45... Drive device, 46... Stopper, 47... Inlet opening.

Claims (1)

Claims: 1. A composite nozzle for merging and guiding at least two flowable reaction components for producing a flowable reaction mixture reacting to produce a plastic, in particular a foam plastic, comprising: a nozzle casing; an insert 5 arranged in the nozzle casing and delimited by a sealing surface 4 which itself tapers towards the axial outlet passage 3; guide holes 2 to 2' which are closed by a pin 11 which is guided in the axial bore 6 of the insert 5 and which fills the outlet passage 3 in the closed position and which is at the same time forcefully controllable 10;
a nozzle needle 7; a needle sleeve 12 which is slidably guided in the area between the insert 5 and the sealing surface 4; a needle sleeve 12 provided inside said needle sleeve 12 and penetrated by the nozzle needle 7; In this case, the inner chamber 22 is connected to the component supply conduit 21, and the needle sleeve 12 is connected to the outlet passage 3.
It has a base 16 having an opening 19 extending towards and aligned with the outlet passageway 3, the outer surface of the base 16 being formed as a sealing surface 17 and at the same time in the closed state. Then, the seal seat 18 cooperates with the seal surface 4 of the casing hole 1.
A supply conduit 23, 24 for at least one further flowable component is provided, the openings 25, 26 of which are located in the area of the sealing surface 4 of the housing bore 2. arranged and in the closed position the sealing surface 1 of the needle sleeve 12
Composite nozzle closed by 7. 2 Multiple openings 2 in supply conduits 23, 24, 27
The composite nozzle according to claim 1, characterized in that nozzles 5, 26 and 28 are assigned. 3. Composite nozzle according to claim 1 or 2, characterized in that the openings 25, 26, 28 are evenly distributed around the central axis. 4. Composite nozzle according to any one of the preceding claims, characterized in that the opening or openings 25, 26, 28 are oriented in the radial direction. 5. Composite nozzle according to any one of claims 1 to 3, characterized in that the opening or openings 25, 26, 28 are oriented tangentially. 6. According to any one of claims 1 to 3, characterized in that the opening or openings 25, 26, 28 occupy an intermediate position between the radial direction and the tangential direction. Composite nozzle as described. 7 A supply conduit 27 for the additional component is provided, the opening 28 of which faces into the guide hole 6 of the nozzle needle 7, the nozzle needle 7 forming a step 29
This step 29 is used as a control edge, so that in the open position of the nozzle needle 7 the opening 28 is freed from the step 29, and in the closed position the large diameter shaft section 30 separates the opening 28 from the step 29. 7. A composite nozzle according to any one of claims 1 to 6, characterized in that the composite nozzle is configured to be hermetically sealed. 8. Composite nozzle according to one of the preceding claims, characterized in that a guide hole 6 for a nozzle needle 7 is arranged in the insert 5. 9. Composite nozzle according to any one of claims 1 to 8, characterized in that the guide hole 6 for the nozzle needle 7 is arranged in the needle sleeve 12. 10 Claims 1 to 9 above, characterized in that it is combined with the forming tool 33 via the contact guides 39, 40 and the corresponding connecting elements 37, 38, 41, 43. A composite nozzle according to any one of the above. 11 A stability chamber 43 located in front of the mold hollow chamber 34 is provided within the surrounding wall of the forming tool 33, and the inlet opening 47 of the stability chamber 43 is aligned with the outlet passage 3 of the nozzle at the connection position of the composite nozzle. 11. Composite nozzle according to claim 10, characterized in that it can be closed by a closing slider (44) guided in a stable chamber (43).