JPH0341813Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a spray gun that is used, for example, when mixing cement mortar and carbon fiber and spraying them onto a mold to produce carbon fiber reinforced cement products. The bundle cutting machine includes a cut fiber spouting passage that sucks the fibers cut by the cutting machine from an opening at one end and jets them out from the opening at the other end using a suction effect caused by the air jet; and the other opening. The present invention relates to a spray gun for producing fiber-containing cement products, in which a nozzle is connected to a mortar jetting passage for jetting cement mortar from an annular opening located concentrically or approximately concentrically with the outer periphery of the spray gun.

As a conventional spray gun for producing this type of fiber-mixed cement product, the one disclosed in Japanese Utility Model Application Publication No. 1983-73560, which was previously proposed by the present applicant, is known. Since the nozzle is directly connected to the cutting machine, the fiber bundles cut by the cutting machine are not given time to open into single fibers, and many fibers are ejected as bundles through the fiber ejection passage. In addition, the amount fluctuates, which makes it difficult to produce cement products that have excellent fiber dispersion and orientation and are stable in quality. The presence of such fibers makes it difficult to defoam and finish using a roller or trowel, resulting in poor workability. especially,
In the case of fiber-reinforced cement products, the cement mortar simply wraps around the cut fiber bundles, and the cement mortar does not stick to each individual fiber, so even though reinforcing fibers are mixed in, sufficient fiber-reinforced cement can be used. Unable to create product.

The purpose of the present invention is to overcome these conventional drawbacks.

A characteristic configuration of the spray gun for producing fiber-mixed cement products according to the present invention, which was taken to achieve the above object, is that the cut fiber spouting passage is provided with a reduced diameter part smaller in diameter than the opening on one end side, and the cutting machine and The present invention is characterized in that a cut fiber retention passage having an appropriate length and having a diameter larger than the diameter of the reduced diameter portion is interposed between the cut fiber ejection passage and the cut fiber ejection passage. The effects of the invention are as follows.

First, since a cut fiber retention passage of an appropriate length is interposed between the cutting machine and the cut fiber ejection passage, the cut fibers cut by the cutting machine are
Due to the suction action of the cut fiber ejection passage, the cut fibers are transported through the cut fiber retention passage which is in a negative pressure state. Therefore, the cut fibers accumulate in the length of the cut fiber accumulation passage until they reach the cut fiber ejection passage, and the cut fibers cannot be opened into single fibers. can. and,
The above-mentioned fiber opening effect is achieved by providing the cut fiber ejection passage with a reduced diameter part having a smaller diameter than the one end side opening, and by making the diameter of the cut fiber retention passage larger than the diameter of the reduced diameter part. will improve dramatically. That is, since the flow velocity of the cut fibers increases after passing through the reduced diameter section, as a reflex effect, the flow velocity of the cut fibers in the cut fiber retention passage becomes sufficiently small, and the flow velocity of the cut fibers in the cut fiber retention passage becomes sufficiently small. It can be retained for a long time until it reaches the passage. Therefore, it is possible to spread the cut fibers very efficiently and reliably while the fibers are stored. Furthermore, since the flow velocity of the cut fibers increases rapidly when passing through the reduced diameter section, the fibers can be opened more efficiently due to the difference in velocity.

Therefore, commercial quality cement products with good fiber distribution and orientation can be produced stably and with good workability, especially for fibers that require cement mortar to be fixed to each fiber. Very useful in making reinforced cement products. In order to fully exhibit the above-mentioned effects, the length of the cut fiber retention passage must be adjusted based on various conditions such as the suction force of the cut fiber ejection passage, the amount of fibers, and the difficulty of opening the fibers. The length and diameter can be determined arbitrarily. For example, when carrying out the present invention, the length of the cut fiber retention passage may be set to 100 to 200 mm. According to this configuration, while the fibers can be opened sufficiently, a situation in which the fibers accumulate below the cut fiber accumulation passage and clog this passage does not occur.

Hereinafter, embodiments of the present invention will be described based on the drawings.

A cutting machine 1 that cuts an unsized carbon fiber bundle A (a pitch-based carbon fiber sliver or tow, both without a binder),
A spray gun used for producing carbon fiber reinforced cement products is constructed by connecting a nozzle 2 which mixes and sprays the cut fibers a and the pumped cement mortar b.

The cutting machine 1 has a plurality of cutter blades 1a on the outer peripheral surface.
. . . 5 cutting rolls 1A, a pair of feed rolls 1B and 1B' that supply the carbon fiber bundle A to the cutting rolls 1A, and this feed roll 1.
It is equipped with a guide tool 1C for guiding a plurality of carbon fiber bundles A, .

The nozzle 2 includes a passage 2A that sucks the fibers cut by the cutter 1 from an opening 2a at one end using a suction action accompanying the air jet and jets the fibers from the opening 2b at the other end, and a passage 2A for jetting the air. and an annular passage 2B for ejecting cement mortar b from an annular opening 2c located concentrically around the outer periphery of the cut fiber ejection opening 2b by utilizing the suction effect caused by the cut fiber ejection opening 2b. One end of the jetting passage 2A has a tapered inner peripheral surface 3 that tapers toward the other end.
The other end side portion of the cut fiber jetting passage 2A has a first cylindrical member 3 having one end side fitted to the other end side of the first cylindrical member 3. The mortar jetting passage 2B is constructed with two cylindrical members 4 and a third cylindrical member 5 and the second cylindrical member 2, which are coaxially mounted on the second cylindrical member 4.
It is configured with an annular gap between it and B.

Between the other end portion of the first cylindrical member 3 and one end portion of the second cylindrical member 4, air is introduced into the cut fiber jetting passage 2A from the annular chamber 6 around the axis X. By blowing out in the direction inclined by the direction, a plurality of first air blowing passages 7 in the circumferential direction are formed in which the cut fibers a are sucked from the one end side opening 2a and are ejected from the cut fiber blowing opening 2b. At the other end of the cylindrical member 5, the cement in the passage 2B is removed by blowing air from the annular chamber 8 around the axis X into the cement mortar injection passage 2B in a direction oblique to the axial direction. A plurality of second air blowing passages 9 in the circumferential direction that blow out the mortar b from the annular opening 2c...
A pair of annular members 10, 10' are attached to form a pair of annular members 10, 10'. The first air blowing passage 7 is a spiral groove around the axis X that applies a swirling force around the axis X to the air as it is ejected, thereby causing the air to spirally swirl. Note that the air supply path 1 to both the annular chambers 6 and 8
1 and 12 are formed inside the third cylindrical member 5.

A cylindrical body 14 is interposed between the cutter 1 and the nozzle 2, which forms a cut fiber retention passage 13 of an appropriate length concentrically with the cut fiber ejection passage 2A.

According to the configuration of the above embodiment, the fiber bundle cut in the cutting machine 1 reaches the nozzle 2 via the cut fiber accumulation passage 13, and when transferred in the cut fiber accumulation passage 13, the fiber bundle is The fibers are woven into single fibers, and in the cut fiber jetting passage 2A,
Since the air is swirling in a spiral, the directional regularity of the cut single fibers is disrupted.

In addition, to give examples of actual values of the dimensions of each part, the diameter D ₁ of the fiber ejection opening 2b is 17.5 mm, the diameter D ₂ of the other end opening of the first cylindrical member 3 is 15 mm, and the cut fiber retention passage 1
The diameter D ₃ of 3 is 55 mm, and the length L of the passage 13 is
It is 100-200mm.

Examples of fibers include carbon fibers and glass fibers.

[Brief explanation of the drawing]

The drawings show an embodiment of the spray gun for producing a fiber-mixed cement product according to the present invention, with FIG. 1 being a longitudinal sectional side view and FIG. 2 being a partially cutaway plan view of the main part. 1... Fiber bundle cutting machine, 2a, 2b... Opening, 2
c...Annular opening, 2A...Cut fiber ejection passage,
2B...Cement mortar jetting passage, 2...Nozzle, 13...Cut fiber retention passage.

Claims (1)

[Claims for Utility Model Registration] 1. The fiber bundle cutting machine 1 uses the suction action of the air jet to cut the fibers a cut by the cutting machine 1.
is sucked through the opening 2a at one end and the opening 2b at the other end.
The cut fiber jetting passage 2A jets out the cut fibers from the opening 2b, and the mortar jetting passage 2B jets the cement mortar b from an annular opening 2c located concentrically or almost concentrically with the outer periphery of the other end side opening 2b. In a spray gun for producing a fiber-mixed cement product to which a nozzle 2 is connected, the cut fiber jetting passage 2A is provided with a reduced diameter portion having a smaller diameter than the one end side opening 2a, and the cutting machine 1 and the cut fiber jetting A spray gun for producing a fiber-containing cement product, in which a cut fiber retention passage 13 of an appropriate length having a diameter D3 larger than the diameter D2 of the reduced diameter portion is interposed between the cut fiber retention passage 2A and the cut fiber retention passage 2A. 2. The spray gun for producing a fiber-mixed cement product according to claim 1, wherein the cut fiber retention passage 13 has a length of 100 to 200 mm. 3. The spray gun for producing a fiber-containing cement product according to claim 1 or 2, wherein the fibers are carbon fibers.