JPH11303593A - Concrete spraying machine - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the deformation of concrete when the impeller collides, thereby reducing the protrusion of concrete from the impeller, increasing the efficiency of concrete ejection, and remaining concrete in the casing. Provided is a concrete spraying machine capable of reducing the amount of rotation, thereby reducing the rotational resistance of the impeller, reducing the wear of the blade of the impeller, and maintaining the performance with a small number of spare parts even when worn. An impeller includes two impeller side plates spaced apart in an axial direction of a rotating shaft, and a plurality of blades mounted between the impeller side plates at an interval in a circumferential direction, and an outer surface of the impeller side plate. Radial projection muscles are arranged on the periphery. An inner end 18a of the concrete discharge pipe 18 on the opposite side to the concrete supply pipe projects radially inward from the inner surface of the casing and is separated from the outermost peripheral position of the blade by a slight gap b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a concrete spraying machine for lining concrete or the like on the inner surface of a tunnel or the like.

[0002]

2. Description of the Related Art As a means for lining inner walls of tunnels, tunnels, cable ducts and the like with concrete or mortar, an air blowing machine schematically shown in FIG. 3 has been conventionally used. This air blowing machine has a nozzle 1 connected to a concrete pump and a pneumatic source, mixes a liquid quick-setting agent into compressed air, blows out ready-mixed concrete from the nozzle 1 with a large amount of compressed air, and at the same time in the nozzle. Fresh concrete and quick-setting admixture are mixed and sprayed on the inner surface of the tunnel. However, such an air blowing machine uses a large amount of compressed air, so not only the power of the pneumatic source is increased, but also dust containing fine concrete and a quick-setting agent contaminates the surroundings with a large amount of compressed air. However, there is a problem that the working environment is extremely bad.

In order to solve this problem, for example, Japanese Utility Model Publication No. 6-45519 discloses a "projection construction apparatus",
A concrete spraying machine capable of lining without using compressed air has been proposed, for example, in "Method and Apparatus for Projecting and Mixing Mixtures" in JP-A No. 3096 and JP-A-6-248887.

FIG. 4 is a view showing the principle of such a concrete spraying machine. As shown in this figure, the heads of these concrete spraying machines have an impeller 2 rotating at a high speed.
And a stirring screw 3 for supplying the impeller 2 while stirring the concrete and the quick-setting agent, and the concrete is projected and sprayed in a tangential direction of the impeller by centrifugal force. Therefore, with this concrete spraying machine, concrete can be mechanically sprayed without using any air, thereby eliminating generation of dust and obtaining a favorable working environment.

However, in the concrete spraying machine shown in FIG. 4, since concrete mixed with a quick-setting binder is inside the head portion, even when the work is stopped for a short time due to interruption of work or the like, the concrete hardens inside. There is a problem that a mechanical failure occurs at the time of restart, or the start itself cannot be performed. For this reason, it is necessary to disassemble and clean the inside each time the work is interrupted, and the handling is complicated, and there is a problem that it takes time for cleaning and maintenance. Further, since the stirring screw 3 and a driving unit (eg, a hydraulic motor) for driving the stirring screw 3 are indispensable in the head, the head becomes large and heavy, and the beam for moving the head, the hydraulic cylinder, and the like become large. there were. In addition, the concrete spraying machine shown in FIGS. 3 and 4 has a problem in that the speed of concrete is greatly reduced due to the discharge resistance of the nozzle portion. Further, when the cross section of the nozzle is enlarged to reduce the reduction in the speed, there is a problem that the projection angle of the concrete becomes too large. Also, with conventional concrete spraying machines,
The nozzle portion and the like are easily clogged with concrete, and its maintenance is difficult. Further, in the concrete spraying machine using the air shown in FIG. 3, there is a problem that the air acts as a cushion and the mixing of the concrete and the quick-setting agent tends to be insufficient.

In order to solve the above-mentioned problems, the same inventors as the present invention invented and applied for a “concrete spraying machine” schematically shown in FIG. 5 (Japanese Patent Application No. 9-2335).
No. 84, unpublished). The concrete spraying machine includes an impeller 12 that rotates at a high speed about an axis, a casing 14 surrounding the impeller at intervals, and a concrete supply pipe provided in the casing and supplying ready-mixed concrete toward a rotation center of the impeller. 16 and a concrete discharge pipe 1 provided in a casing adjacent to the concrete supply pipe.
8 and a quick-setting agent supply nozzle 20 provided outside the open end of the concrete discharge tube for injecting a liquid quick-setting agent toward the concrete passing through the concrete discharge tube. The pipe 18 is a straight pipe having an axis inclined toward the center of the impeller from the rotation direction of the impeller orthogonal to the concrete supply pipe and having no change in cross section from the casing.
In this figure, 6 is a concrete pipe, 7 is ready-mixed concrete, 8 is a quick setting agent, and 13 is a blade.

In this concrete spraying machine, hardening of the concrete inside the head portion can be suppressed, thereby eliminating the need for cleaning and maintenance every time the work is interrupted, and reducing the size and weight of the head portion. Can be
This makes it possible to reduce the size of the beam or hydraulic cylinder that moves the head, reduce the discharge resistance while maintaining the spotting property of concrete projection, and reduce the speed drop.
It is characterized in that concrete is hardly clogged in each part, the internal maintenance is easy, and the mixing property of concrete and quick-setting agent is high.

[0008]

However, it has been found that the concrete spraying machine shown in FIG. 5 has the following problems. When the impeller 12 collides with the concrete 7 supplied into the casing 14 from the concrete supply pipe 16, the concrete is easily deformed greatly, and a part of the concrete protrudes into the gap between the impeller and the casing, thereby causing resistance. The launching efficiency tends to decrease. Concrete that cannot be projected by the impeller 12 tends to remain in the casing, and this residual concrete increases the rotational resistance of the impeller. The blade 13 of the impeller is liable to be worn, and it is necessary to sufficiently prepare a spare blade.

The present invention has been made to solve such a problem. That is, the main object of the present invention is to
An object of the present invention is to provide a concrete spraying machine that can reduce the amount of concrete protruding from an impeller and increase the efficiency of concrete ejection. Another object of the present invention is to provide a concrete spraying machine capable of reducing the amount of concrete remaining in a casing and thereby reducing the rotational resistance of an impeller. Furthermore, another object of the present invention is to reduce impeller blade wear,
Another object of the present invention is to provide a concrete spraying machine that can maintain its performance with a small number of spare parts even when worn.

[0010]

According to the present invention, an impeller that rotates at a high speed about an axis, a casing surrounding the impeller with a space between the impeller, and an impeller provided in the casing toward a rotation center of the impeller are provided. In a concrete spraying machine having a head portion having a concrete supply pipe for supplying concrete and a concrete discharge pipe provided in a casing adjacent to the concrete supply pipe, the impeller is spaced apart in an axial direction of a rotating shaft. A concrete spraying machine is provided, comprising: two impeller side plates separated by a plurality of blades; and a plurality of blades mounted at intervals in the circumferential direction therebetween.

According to the configuration of the present invention, since the outer peripheral edge of the impeller side plate has radial projections, the flow of the liquid portion of the concrete from a to b and c due to the centrifugal force is not c. The flow of d becomes dominant. Even if the casing side is open like e, it does not flow out,
Even if the circuit is delayed, it is projected from the discharge port, and the concrete ejection efficiency can be increased.

Further, according to the present invention, an impeller that rotates at a high speed about an axis, a casing surrounding the impeller at a distance, and ready-mixed concrete supplied to the rotation center of the impeller provided in the casing. In a concrete spraying machine having a head portion having a concrete supply pipe and a concrete discharge pipe provided in a casing adjacent to the concrete supply pipe, the impeller is provided with a space provided in the axial direction of a rotating shaft. And two impeller side plates,
The concrete discharge pipe comprises a plurality of blades mounted at intervals in the circumferential direction therebetween, and the inner end of the concrete discharge pipe opposite to the concrete supply pipe projects radially inward from the inner surface of the casing and the outermost circumferential position of the blade. A concrete spraying machine characterized by being slightly spaced from the concrete spraying machine.

According to this structure, the inner end of the concrete discharge pipe opposite to the concrete supply pipe projects radially inward from the inner surface of the casing and is slightly spaced from the outermost peripheral position of the blade. Even when the concrete deforms when the blade collides with the impeller and a part of the concrete protrudes into the gap between the impeller and the casing, the inner end of the concrete discharge pipe functions as a scraper part, and the concrete protruding from the outermost peripheral position of the blade Can be removed and introduced into the concrete discharge pipe. Therefore, introduction of concrete into the casing /
Residuals can be suppressed, and the rotational resistance of the impeller can be reduced.

According to a preferred embodiment of the present invention, the casing has a casing side plate surrounding the impeller side plate at intervals and a casing body surrounding the blades at intervals, and the casing side plate has residual concrete. And a through hole for discharging air. According to this configuration, even if concrete leaks out after passing between the outer peripheral edge of the impeller side plate and the casing side plate, residual concrete is discharged by rotation of the impeller, and the rotational resistance of the impeller can be further reduced.

Further, the blade can be mounted such that the outer end and the inner end in the radial direction are opposite to each other and the position of the outer end can be shifted in the radial direction. With this configuration, even when the outer end of the blade is worn, the life can be doubled by attaching the outer end and the inner end oppositely, and the performance can be maintained with a small number of spare parts. In particular, when the projection amount of concrete is small, abrasion of the blade can be greatly reduced by shifting a part (for example, half) of the blade inward in the radial direction, thereby further reducing the wear of the blade. The product can maintain its performance.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, the same reference numerals are given to the common parts in the respective drawings, and the duplicate description will be omitted. FIG. 1 is a diagram showing a use state of the concrete spraying machine of the present invention. In this figure, reference numeral 4 denotes a main engine, which has a traveling portion 4a, and a concrete pump 4b is provided on the rear side. A robot arm mechanism 5 is provided in front of the main machine 4. In this example, the robot arm mechanism 5 includes a main beam 5a, a traverse cylinder 5c provided on a telescopic rod 5b of the main beam 5a, a linear motion cylinder 5d, a base 5e provided on a rod end of a linear motion cylinder 5e, and the like. Thus, the head unit 10 can be moved to any position and direction.

FIG. 2 is an overall structural view of a concrete spraying machine head according to the present invention, in which (A) is a front view in which a part is sectioned, and (B) is a cross-sectional view taken along line AA of (A). It is. As shown in FIG. 2A, the head 10 of the concrete spraying machine according to the present invention includes an impeller 12, a casing 14, a concrete supply pipe 16, and a concrete discharge pipe 18. The impeller 12 is composed of two impeller side plates 12a spaced apart in the axial direction of the rotation axis Z, and a plurality of (four in this figure) blades 13 mounted therebetween at intervals in the circumferential direction. A high-speed rotation is performed clockwise in this figure around an axis O by a driving device (for example, a hydraulic motor) not shown. The casing 14 surrounds the impeller 12 at intervals. Further, the concrete supply pipe 16 is provided integrally with the upper part of the casing 14,
It is connected to a concrete pump 4b via a concrete pipe 6 (see FIG. 1), and supplies (pressurizes) the ready-mixed concrete 7 toward the rotation center of the impeller 12.

As shown in FIG. 2A, the concrete discharge pipe 18 is provided integrally with the casing 14 adjacent to the concrete supply pipe 16. The concrete discharge pipe 18 is a straight pipe whose cross section does not change from the casing 14, and is preferably a short pipe having a rectangular cross section. With this configuration, the axis Z of the concrete discharge pipe 18 can be made coincident with the projection direction of the concrete 7,
Discharge resistance can be greatly reduced. In addition, by making the cross section a rectangular short tube, it is possible to conform to the normal shape of the casing 14 and prevent the spread of the concrete 8 without reducing the speed of the concrete 8 projected by the impeller 12, thereby preventing the concrete 8 from spreading. Can be held.

Further, as shown in FIG. 2B, since the outer peripheral edge of the impeller side plate 12a has radial projections, the liquid portion of the concrete flows out of a to b and c due to centrifugal force. However, the flow of d instead of c becomes dominant. Even if the casing side surface is open as shown by e, it does not flow out, and even if the circuit is delayed, it is projected from the discharge port, and the concrete discharging efficiency can be increased. FIG.
In (A), the distance a between the inner end of the concrete supply pipe 16 and the outermost peripheral position of the blade 13 is preferably set to about the size of the aggregate contained in the concrete, for example, about 10 mm. As a result, the concrete put in
The wear of the blade at the time of cutting can be reduced. Further, the outermost edge of the blade 13 is attached to the inner side by a distance e from the outer peripheral edge of the impeller side plate 12a. The interval e is preferably, for example, about 20 mm. With this configuration, when the blade 13 strikes concrete, concrete is reliably held between the impeller side plates 12a,
The protrusion of the concrete between the impeller side plate 12a and the casing can be reduced.

Further, according to the present invention, as shown in FIG. 2A, the inner end 18a of the concrete discharge pipe 18 opposite to the concrete supply pipe 16 is located radially inward of the inner surface of the casing 14. It protrudes and is separated from the outermost peripheral position of the blade by a slight gap b. The gap b is preferably, for example, about 3 mm. With this configuration, even when the concrete deforms when the blade 13 collides with the concrete and a part thereof protrudes into the gap between the impeller 12 and the casing 14, the inner end 18a of the concrete discharge pipe 18 functions as a scraper part. , Blade 12
The concrete 7 protruding from the outermost peripheral position can be removed and introduced into the concrete discharge pipe 18.
Therefore, the introduction / residual of the concrete into the casing 14 can be suppressed, and the rotational resistance of the impeller 12 can be reduced.

As shown in FIGS. 2A and 2B, the casing 14 includes a casing side plate 14a surrounding the impeller side plate 12a at intervals and a casing body 14b surrounding the blade 13 at intervals. Become. Further, according to the present invention, the casing side plate 14a is provided with the through hole 15 for discharging the residual concrete. With this configuration, the concrete is introduced into the casing 14 through the scraper portion (the inner end portion 18a), and even if there is a possibility that the concrete is filled between the impeller side plate 12a and the casing side plate 14a, the rotation of the impeller 12 is achieved. As a result, residual concrete can be discharged, and the rotational resistance of the impeller can be further reduced.

Further, as shown in FIG. 2A, each blade 13 is formed symmetrically in the radial direction so that the outer end and the inner end in the radial direction can be oppositely mounted on the blade mounting plate 12b. With this configuration, even when the outer end of the blade 13 is worn, the life can be doubled and the performance can be maintained with a small number of spare parts by mounting the outer end and the inner end opposite to each other. Further, as shown in FIG. 2 (A), each blade 13 can be attached by circulating the outer end position of the blade 13 in the radial direction, for example, by changing a bolt position. With this configuration, especially when the projection amount of the concrete is small, a part (for example, half) of the blade 13 can be shifted inward in the radial direction and attached, so that the wear of the blade can be significantly reduced. Further, performance can be maintained with fewer spare parts.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

[0024]

As described above, the concrete spraying machine of the present invention can reduce the protrusion of concrete from the impeller, increase the efficiency of concrete ejection, and reduce the amount of concrete remaining in the casing. The impeller rotation resistance can be reduced, the impeller blade wear can be reduced, and even if worn,
It has excellent effects such as performance can be maintained with few spare parts.

[Brief description of the drawings]

FIG. 1 is a view showing a use state of a concrete spraying machine of the present invention.

FIG. 2 is a configuration diagram of a head portion of the concrete spraying machine of the present invention.

FIG. 3 is a schematic view of a conventional air blowing machine.

FIG. 4 is a configuration diagram of a head portion of a conventional concrete spraying machine that does not use air.

FIG. 5 is a schematic view of a head section of an unpublished prior application.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle 2 Impeller 3 Stirring screw 4 Main machine 5 Robot arm mechanism 6 Concrete pipe 7 Fresh concrete 8 Quick setting agent 10 Head part 12 Impeller 12a Impeller side plate 12b Blade mounting plate 13 Blade 14 Casing 14a Casing side plate 14b Casing body 15 Through hole 16 Concrete supply pipe 18 Concrete discharge pipe 18a Inner end part (scraper part) 20 Quick setting agent supply nozzle

Claims (4)

[Claims] An impeller that rotates at a high speed about an axis;
A casing surrounding the impeller at intervals, a concrete supply pipe provided in the casing to supply ready-mixed concrete toward the rotation center of the impeller, and a concrete discharge pipe provided in the casing adjacent to the concrete supply pipe. Wherein the impeller comprises two impeller side plates spaced apart in the axial direction of the rotating shaft, and a plurality of blades mounted at intervals therebetween in the circumferential direction. Characterized in that radial projections are arranged on the outer peripheral edge of the impeller side plate. 2. An impeller that rotates at a high speed about an axis,
A casing surrounding the impeller at intervals, a concrete supply pipe provided in the casing to supply ready-mixed concrete toward the rotation center of the impeller, and a concrete discharge pipe provided in the casing adjacent to the concrete supply pipe. Wherein the impeller comprises two impeller side plates spaced apart in the axial direction of the rotating shaft, and a plurality of blades mounted at intervals therebetween in the circumferential direction. Wherein the inner end of the concrete discharge pipe opposite to the concrete supply pipe projects radially inward from the inner surface of the casing and is slightly spaced from the outermost peripheral position of the blade. Machine. 3. The casing has a casing side plate surrounding the impeller side plate at intervals and a casing body surrounding the blade at intervals, and the casing side plate has a through hole for discharging residual concrete. The concrete spraying machine according to claim 1, comprising: 4. The concrete spraying machine according to claim 1, wherein the blade has a radially outer end and an inner end which can be mounted opposite to each other.