JPH0353090B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a mixing head for multi-component liquid plastic raw materials, and more specifically, the present invention relates to a mixing head for multi-component liquid plastic raw materials, and more specifically, the head body is provided with a circulation passage for each raw material liquid, and This invention relates to an improvement in a mixing head of a type in which a rod-shaped valve body that is reciprocatably inserted into a hole is not provided with a groove (overflow groove: see Japanese Patent Publication No. 1533/1983) on the outer peripheral surface.
Such a mixing head has the advantage that the mixing chamber can be made as small as possible compared to the above-mentioned one in which grooves are formed on the outer circumferential surface, and better mixing and collision results can be obtained.

<Prior art> Conventionally, as the above type of mixing head, the 11th,
The one shown in Figure 12 was found (Jitko Sho 58-35466
(see publication). A through hole 2 is formed in the head body 1 in the axial direction of the plunger 18, and a cylinder chamber 3, which is parallel to the top and bottom of the through hole 2,
4 is formed. A rod-shaped valve body 5 is provided in the through hole 2, and a switching valve 6 is provided in each cylinder chamber 3, 4.
7 are respectively fitted and fixed to the rod of the plunger 18 so that they reciprocate in synchronization. On each side of the through hole 2, ejection holes 10 and 11 for liquid A (for example, polyol) and liquid B (for example, isocyanate) are communicated with liquid inlets 8 and 9. On the other hand, each cylinder chamber 3, 4 is communicated with each liquid outlet 12, 13 for the raw material liquid. Circulation channels 14 and 1 are provided between the through hole 2 and the cylinder chambers 3 and 4.
5 is formed.

FIG. 11 is a sectional view of the mixing head showing the state when the rod-shaped valve body 5 is located at the front dead center. At this time, each raw material liquid is pumped from the raw material tank to the liquid inlet 8 to the circulation flow path by a pump (not shown). 14→Cylinder chamber 3→
Liquid outlet 12 → Raw material tank or raw material tank → Liquid inlet 9 → Circulation channel 15 → Cylinder chamber 4 → Liquid outlet 13 →
Raw materials are dunked and recycled.

Thereafter, when the rod-shaped valve body 5 is located at the after dead center as shown in FIG. Each raw material liquid is ejected at high pressure from 10 and 11, collides and mixes in a mixing chamber 19 formed by the tip surface of the rod-shaped valve body 5, the inner wall of the through hole, and a mold (not shown), and moves forward in the axial direction of the rod-shaped valve body 5. be ejected.

<Problems to be Solved by the Invention> According to the mixing head shown in FIGS. 11 and 12, the mixing chamber 19 can certainly be made smaller. However, since as many cylinder chambers as the number of raw material liquids to be mixed into the head body 1 are formed, the head body becomes larger, and a switching valve is also disposed in each cylinder chamber, resulting in a large number of parts. However, there was a problem in that it took time and effort to assemble. In addition, in the mixing head technology described in JP-A-59-158235, the switching valves are rotary valves, but the configuration is also such that there are as many switching valves as there are raw material liquids, and the same problem arises. It was hot.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve such problems and provide a mixing head in which the head body is miniaturized while maintaining the advantage that the mixing chamber can be made as small as possible, and the number of parts does not increase. .

<Means for Solving the Problems> The present invention has been made to solve the above problems, and the head main body is provided with a through hole, and each raw material is opened in the side wall of the through hole. A liquid spout is provided, and a rod-shaped valve body is fitted into the through hole so as to be able to reciprocate, and when the rod-shaped valve body is located at the front dead center, each raw material liquid is circulated between it and the raw material tank, In the mixing head configured such that when the rod-shaped valve body is located at the rear dead center, each raw material liquid is collided and mixed and is injected in the front axial direction of the rod-shaped valve body, one cylinder chamber is formed in the head body. , the circulation flow path for each of the raw material liquids is separated by a side wall of the cylinder chamber on the circulation direction side of each of the jet ports, and the cylinder chamber is capable of accommodating an opening of each of the circulation flow paths. The mixing head is configured such that a rod-shaped switching valve having a conduction part and a sealing part is inserted into the mixing head so as to be able to reciprocate in the axial direction, thereby communicating or blocking the divided circulation flow path.

<Example> Hereinafter, the present invention will be explained in detail by taking a mixing head for reaction injection molding of urethane as an example.

First Embodiment FIG. 1 is a half-sectional view of the mixing head 21 of this embodiment, and FIG. 2 is a schematic perspective view showing the circulation flow path for liquid A (polyisocyanate component) and liquid B (polyol component). .

The head body 23 of the mixing head 21 of the embodiment has a through hole 2 located on the extension line of the sprue of the mold.
5 is bored, and a rod-shaped valve body 51 is inserted into this through hole 25.
(see Fig. 5) is fitted so as to be slidable in the axial direction. As shown in FIG. 2, a liquid inlet 27 for liquid A is formed on one side of the head body 23.
A circulation channel 29 for liquid A is formed above the through hole 25 . Similarly, the through hole 2 is connected to the B liquid inlet 31 formed on the other side of the head body 23.
A circulation flow path 33 for the B liquid is formed below the B liquid. Each circulation flow path 29, 33 has a jet port 28, 32 facing the through hole 25 in the front cylindrical portion 24 of the head body 23. Of course, these spouts 2
The axes of 8 and 32 coincide. Each of the circulation channels 29 and 33 rises upward on the same plane at the rear portion of the head body 23, and is once separated by the cylinder chamber 35.
Reach 9.

A switching valve 41 is fitted into the cylinder chamber 35 so as to be movable in the axial direction of the cylinder chamber 35, as shown in FIG. It is desirable that the switching valve 41 is controlled by the same hydraulic system as the rod-shaped valve body 51, and that the movement of both is synchronized. The switching valve 41 has large diameter portions 43 and 44 that serve as seals with the same diameter as the cylinder chamber 35.
The small diameter portions 45 and 46 that serve as the conductive portions are connected to each circulation flow path 2.
9 and 33. This small diameter part 4
5 and 46 are circulation channels 29 and 33 as shown in FIG.
An opening 3 divided by a cylinder chamber 35 of
0 and 34 at the same time, and liquids A and B are simultaneously distributed from bottom to top as shown in FIG. In addition, Figure 4 is the 3rd
It is a partial sectional view shown in the − arrow line in the figure, and when the small diameter portion 45 faces the opening 30 in this way,
The circulation flow path 29 is communicated with the annular gap 47 formed between the small diameter portion 45 and the peripheral wall of the cylinder chamber 35 . Similarly, the circulation flow path 33 is communicated with the annular gap 48. On the other hand, when the switching valve 41 moves to the left in FIG.
4 simultaneously face each opening 30, 34 of the circulation channels 29, 33, and the annular gaps 47, 48 are simultaneously closed. Therefore, by reciprocating one switching valve 41, the circulation channels 29, 3 for liquid A and liquid B are
3 will be communicated and shielded at the same time.

Next, the rod-shaped valve body 51 that is inserted into the through hole 25 of the head body 23 will be explained.

FIG. 5 shows a side view of the rod-shaped valve body 51, and the rod-shaped valve body 51 of the embodiment has a rod portion 53, a first seal groove portion 5,
5, a shield valve part 57, a second seal part 59, and a throttle valve part 65, and a flange part 61 attached to a piston 77 of an actuating device 75 is provided at the rear end (see FIG. 1). An oval keyway 54 is bored in the middle of the rod portion 53. Also,
Seal grooves 56 and 58 are formed in the first seal part 55 and second seal part 59 in the circumferential direction, respectively, and when liquids A and B flow into these grooves 56 and 58, they react to form a urethane seal. , exhibits a self-sealing effect. Of course, a seal ring may be attached to each seal groove 56, 58.

The horizontally elongated portion formed from the second seal portion 59 to the shielding portion 57 and the first seal portion 55 indicates the circumferential surface of the seal member 63, and the seal member 61 is made of fluorocarbon resin having a substantially trapezoidal cross section with an arcuate upper side. As shown in FIG. 6 (cross-sectional view taken along the - arrow line in FIG. 5), two dovetail grooves 63 formed on both sides of the rod-shaped valve body 51 are implanted. When the shielding valve part 57 shields the jet ports 28 and 32 (the state shown in FIG. 1), this sealing member 61 brings its outer circumferential surface into close contact with the peripheral wall of the through hole 25.
The liquid and B liquid are prevented from leaking through the shielding valve portion 57 in the circumferential direction. The sealing member 61 is not limited to the above-mentioned fluororesin as long as it is made of a material softer than the peripheral wall of the through hole 25 (usually made of steel), and may also be made of other synthetic resins such as polyacetal, soft metals, ceramics, etc. It can also be formed using

A throttle valve portion 65 formed at the tip of the rod-shaped valve body 51
As shown in FIG. 7, protruding pieces 67 and 69 having an arcuate cross section are formed on the upper and lower sides, and are formed separately from the other parts constituting the rod-shaped valve body 51, and are fixed by screws or other means. It can be rotated by loosening the set screw.

When the piston 77 of the actuating device 75 is moved to the left in the figure from the state of FIG. 1 in which the rod-shaped valve body 51 is at the front dead center, and the rod-shaped valve body 51 is positioned at the rear dead center (see FIG. 8), The throttle valve part 65 that protrudes from the head body 23 to the outside is connected to each circulation flow path 2 for liquid A and liquid B.
9 and 33, facing the jet ports 28 and 32. At this time, Fig. 9 (showing a cross section along the - arrow line in Fig. 8)
As shown, the upper protruding piece 67 shields the spout 28 by a predetermined amount, and similarly the lower protruding piece 69 shields the spout 32 by a predetermined amount. Then, as shown in FIG. 9, when the set screw is loosened, the throttle valve part 65 is rotated left and right, and the set screw is tightened again at the desired position, the opening amount of the spout ports 28 and 32 can be adjusted steplessly, and the protruding piece 67,
69 are formed symmetrically, the opening amount of each jet port 28, 32 is increased or decreased in proportion.

Note that FIG. 10 shows a sectional view of the same portion as FIG. 9 when the rod-shaped valve body 51 is at the front dead center (cross-sectional view taken along the - arrow line in FIG. 1). Each circulation channel 29,
The openings 28 and 32 of 30 are completely shielded by a shield valve section 57.

Next, the operation of the mixing head 21 will be explained.

First, as shown in FIG. 1, the rod-shaped valve body 51 is positioned at the front dead center, and as shown in FIG.
0,34. Then, pumps (not shown) are operated to transport liquid A and liquid B to each raw material tank (not shown), so that liquid inlet 27→circulation channel 19→annular gap 47→liquid outlet 37 or liquid inlet 31
→ Circulation channel 33 → annular gap 48 → liquid outlet 39 to circulate for a predetermined time.

Next, as shown in FIG. 8, the rod-shaped valve body 51 is positioned at the rear dead center, and the switching valve 41 shown in FIG. to simultaneously shield each circulation flow path 29, 30. Then, A is pressurized to high pressure by the pump.
The liquid and the B liquid are ejected at high pressure from the respective ejection ports 28 and 32 as shown in FIG. 9, collide and mix within the throttle valve portion 65, and are ejected axially forward of the rod-shaped valve body 51.

After that, when the rod-shaped valve body 51 is again positioned at the front dead center (the state shown in FIG. 1), the throttle valve part 65 will be in a state of protruding from the front end surface of the front cylindrical part 24 of the head body 23, so that it can be adjusted as necessary. It becomes possible to perform cleaning.

In addition, in the mixing head 21, the ejection ports for each raw material liquid may be formed at deeper positions than the through holes 25, and in that case, the rod-shaped valve body 51 is correspondingly shortened, so that when it is at the front dead center, However, the throttle valve portion 65 no longer protrudes from the head body 23.

In addition, when mixing three or more types of raw material liquids,
Form liquid inlets, circulation channels, jet ports, and liquid outlets according to the number of raw material liquids. At this time, each jet port is designed so that its axis intersects approximately at the center of the through hole 25,
A cylinder chamber is formed to linearly penetrate each circulation channel. Further, an axial sealing member is embedded in the circumferential surface of the shielding valve portion of the rod-shaped valve body so as to divide each jet port.

The mixing head 21 of this embodiment, which has been explained above,
, the characteristic feature is that the circulation flow paths 29 and 33 for each raw material liquid are separated by opening to the side wall of the cylinder chamber 35 on the circulation side from the respective jet ports 28 and 32; Small diameter portions 45, 4 that communicate the divided circulation channels 29, 33
6 and a large diameter portion 4 that shields each circulation flow path 29, 33.
A switching valve 41 having valves 3 and 44 is inserted therein.

Further, when the switching valve is caused to reciprocate in the axial direction, the cross-sectional shapes of the switching valve and the cylinder chamber are not limited to circular shapes, but may be square, hexagonal, etc. in cross-section.

<Effects of the Invention> As explained above, the mixing head of the present invention has the following effects:
One cylinder chamber is formed in the head body, and the circulation flow path for each raw material liquid is divided from the side wall of the cylinder chamber on the circulation side of each jet port, and the divided circulation flow paths are communicated in the cylinder chamber. Alternatively, the valve is characterized by a structure in which a rod-shaped switching valve for shielding is inserted so as to be able to reciprocate. Therefore, no matter how many raw material liquids are mixed by collision, one cylinder chamber and one switching valve can communicate or block the circulation channels of each raw material liquid. Therefore, compared to the conventional mixing head, the mixing head of the present invention has a smaller head main body, a reduced number of parts, and easier assembly.

[Brief explanation of drawings]

The figure shows the configuration of a mixing head, and FIG. 1 shows a rod-shaped valve body 51 in a mixing head according to a first embodiment of the present invention.
A half-sectional view showing the state where is at front dead center, Figure 2 is A
A schematic perspective view showing the circulation flow path of liquid and B liquid, FIG. 3 is a sectional view taken along the arrow line in FIG. 1 showing the switching valve 41, and FIG. Figure 5 shows a rod-shaped valve body 51.
6 is a cross-sectional view taken along the - arrow line in FIG. 5, FIG. 7 is a perspective view showing the throttle wall 65, and FIG. 8 is a mixing head showing a state in which the rod-shaped valve body 51 is at the rear dead center. 21, FIG. 9 is a half-sectional view of the spout 71,
A sectional view along the arrow line in FIG. 8 showing 73,
FIG. 10 is a cross-sectional view along the − arrow line in FIG.
11 and 12 are cross-sectional views of a conventional mixing head. 21...Mixing head, 23...Head body, 2
5...Through hole, 28, 32...Ejection port, 29,3
3...Circulation channel, 35...Cylinder chamber, 41...
Switching valve, 43, 44...Large diameter part, 45, 46...
...Small diameter portion, 51... Rod-shaped valve body.

Claims (1)

[Scope of Claims] 1. The head body is formed with a through hole, and is provided with a spout for each raw material liquid that opens on the side wall of the through hole, and a rod-shaped valve body can reciprocate into the through hole. When inserted and inserted, when the rod-shaped valve body is located at the front dead center, each of the raw material liquids is circulated between each raw material tank, and when the rod-shaped valve body is located at the rear dead center,
In the mixing head configured such that the raw material liquids are collided and mixed and injected in the front axial direction of the rod-shaped valve body, one cylinder chamber is formed in the head main body, and a cylinder chamber is formed in the head body to provide a circulation flow path for each of the raw material liquids. The cylinder chamber is divided by a side wall on the side of the circulation direction from each of the jet ports, and the cylinder chamber has a rod-shaped part having a conductive part and a seal part so as to correspond to the opening of each of the circulation channels. A mixing head characterized in that a switching valve is fitted so as to be able to reciprocate in the axial direction to communicate or cut off the divided circulation flow path.