JPH11350891A - Concrete gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete gun capable of preventing a leakage from a clearance between an impeller side plate and a casing by a member having resistance against wear, improving resistance against wear of a blade mounting face of an inner face of the impeller side plate and a blade end face, and reducing friction of the inside of a discharge pipe. SOLUTION: A head part 10 of a concrete gun is provided with an impeller 12, a casing 14, a concrete supply pipe 16, and a concrete discharge pipe 18. The impeller 12 consists of two impeller side plates 12a arranged across an interval in the axial direction of a rotary shaft and a plurality of blades 13 attached across an interval in the peripheral direction therebetween, and fins 24 having resistance against wear are inclined in the radial direction and arranged across an interval at a peripheral fringe of an outer face of the impeller side plate 12a. Moreover, a plurality of discharge pipe openings 28 are provided on a side face and a top face of a concrete discharge pipe 18. Since air enters along an inner wall of the concrete discharge pipe 18 from the discharge pipe openings 28 together with concrete when concrete is discharged, friction between concrete and the inner wall is reduced.

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. 6 has conventionally been 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. 7 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. 7, since the concrete mixed with the quick setting agent is inside the head portion, even when the work is stopped for a short time due to interruption of work, 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. Further, the concrete spraying machine shown in FIGS. 6 and 7 has a problem that the speed of the 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. 5, 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 have created and applied for a “concrete spraying machine” schematically shown in FIG. 8 (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. 7 has the following problems. There is a gap of several mm between the impeller side plate and the casing side plate, and concrete leaks from this gap. The vicinity of the blade mounting position on the inner surface of the impeller side plate is easily worn. The blade of the impeller is easily worn. The friction between the inner wall surface of the discharge pipe and the concrete is large, and the concrete projection speed decreases.

The present invention has been made to solve such a problem. That is, an object of the present invention is to prevent leakage from the gap between the impeller side plate and the casing with a wear-resistant member, improve the wear resistance of the blade mounting surface on the inner surface of the impeller side plate, and improve the blade end surface. It is an object of the present invention to provide a concrete spraying machine which improves the abrasion resistance of the concrete and further reduces the friction of the inner surface of the discharge pipe.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, an impeller that rotates at a high speed about an axis, a casing that surrounds the impeller at intervals, and a casing provided on the casing are provided. In a concrete spraying machine having a head portion having a concrete supply pipe for supplying ready-mixed concrete toward a rotation center of an impeller, and a concrete discharge pipe provided in a casing adjacent to the concrete supply pipe, the impeller includes: A pair of impeller side plates spaced apart in the axial direction of the rotating shaft, and a plurality of blades mounted therebetween at intervals in the circumferential direction, and wear-resistant fins on the outer peripheral edge of the impeller side plate. Are arranged at intervals and inclined with respect to the radial direction.

According to the structure of the present invention, by arranging abrasion-resistant fins inclined in the radial direction on the outer peripheral edge of the impeller side plate, the concrete entering the gap between the impeller side plate and the casing can be removed in the circumferential direction. Let it flow into the concrete discharge pipe. Fins are wear-resistant materials,
Low wear on concrete. Further, by arranging the fins at an angle, the rotational resistance of the impeller can be reduced.

According to the second aspect of the present invention, an impeller that rotates at a high speed about an axis, a casing surrounding the impeller with a space therebetween, and concrete that supplies ready-mixed concrete toward a rotation center of the impeller provided in the casing. In a concrete spraying machine provided with a head having a supply pipe and a concrete discharge pipe provided in a casing adjacent to the concrete supply pipe, the impeller includes two impellers spaced apart in an axial direction of a rotation shaft. And a plurality of blades circumferentially spaced apart and radially mounted between the impeller side plates. Attached to.

The surface of the blade that is in contact with the concrete wears. In particular, since the outer edge of the surface in contact with the concrete in the radial direction is severely worn, an abrasion-resistant chip is attached to this portion so that the surface in contact with the concrete is flush with the surface of the other blade. Thus, wear of the blade can be prevented.

According to the third aspect of the present invention, a wear-resistant tip is mounted flush with the blade mounting position on the inner peripheral surface of the impeller side plate.

At the blade mounting position on the outer periphery of the inner surface of the impeller side plate, concrete is severely worn and dents are generated. Therefore, an abrasion-resistant chip is embedded in this portion so that the surface is flush with the inner surface of the impeller side plate. Thereby, the occurrence of the dent can be prevented.

According to the fourth aspect of the present invention, a plurality of openings are provided at the base of the concrete discharge pipe.

The discharged concrete hits the inner wall of the discharge pipe near the base of the concrete discharge pipe, and the concrete projection speed decreases due to frictional resistance. Therefore, by providing an opening at the base of the discharge pipe, the outside air is drawn into the discharge pipe along the inner wall of the discharge pipe, so that the frictional resistance between the concrete and the inner wall is reduced, and the decrease in the concrete projection speed is reduced. And the projection performance is improved.

[0018]

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 sectional view taken along line XX of (A). . FIG.
As shown in FIG. 1A, a head 10 of a 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 includes two impeller side plates 12a spaced apart in the axial direction of the rotation axis Z, and a plurality of impellers 12 (four in this figure) attached at intervals in the circumferential direction therebetween.
And is rotated clockwise at high speed around the 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 integrally provided on the upper part of the casing 14 and connected to the concrete pump 4b via the concrete pipe 6 (see FIG. 1) so that the ready-mixed concrete 7 is supplied (pumped) toward the rotation center of the impeller 12. Has become.

Further, 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. A plurality of discharge pipe openings 28 are provided on the side and top surfaces of the concrete discharge pipe 18. When the concrete is discharged, the concrete is taken along with the concrete, and air is discharged from the discharge pipe opening 28 along the inner wall of the concrete discharge pipe 18. Because it enters, the friction between the concrete and the inner wall is reduced,
The decrease in the concrete projection speed is alleviated, and the projection performance is improved.

As shown in FIGS. 2A and 2B, the outer peripheral edge of the impeller side plate 12a is inclined in the radial direction,
Outer fins 24 are provided to protrude from the outer surface. By rotating the impeller 12, the concrete flowing in from the gap between the casing 14 and the impeller side plate 12 a is prevented, and the concrete flows out from the concrete discharge pipe 18. By inclining the outer fins 24, the rotational resistance of the impeller is reduced. Further, since the outer fins 24 are made of a wear-resistant material, the wear is small.

Further, as shown in FIG. 2A, the blade 13 is joined to the blade supporting member 13a by bolts 13b with the surface to be contacted with the concrete in the radial direction. Both ends of the blade support 13a are fixed to both impeller side plates 12a with bolts. Abrasion-resistant blade end tips 22 are embedded at both end surfaces in the radial direction of the surface of the blade 13 that comes into contact with concrete so as to be flush with the blade surface. Although the wear of the blade 13 is concentrated on the outer end face in the radial direction, by attaching the blade end tips 22 to both end faces, when one of the wear
By inverting and attaching 3, the blade end tip 22 can be quickly replaced. As described above, the abrasion of the blade 13 can be reduced by embedding the blade end tip 22.

As shown in FIGS. 2A and 2B, an abrasion-resistant inner chip 26 is provided on the mounting surface of the blade 13 near the inner periphery of the impeller side plate 12a on the same plane as the inner surface of the impeller side plate 12a. It is embedded to be. In the vicinity of the outer periphery of the inner surface of the impeller side plate 12a, the mounting position of the blade 13 is severely worn by concrete, but by mounting the inner chip 26 having abrasion resistance, the wear at that position can be reduced.

FIG. 3 shows a detailed structure of the outer fin 24.
(A) is a plan view, (B) is an XX sectional view of (A),
(C) is a YY sectional view of (A). Outer fin 24
The underside shape of the is stepped, the cross section is reverse tapered,
The impeller side plate 12a is also shaped accordingly.
There is some play between each other. Outer fin 2
Reference numeral 4 projects from the impeller side plate 12a by about 3 mm. The outer fins 24 are formed by sintering ceramics such as cemented carbide or silicon carbide, and all have excellent wear resistance. After the outer fins 24 are fitted into the impeller side plates, an adhesive is filled and fixed. Since the adhesive is used at room temperature and does not require heating or the like, the material of the outer fins 24 does not deteriorate.

FIG. 4 shows the detailed structure of the inner chip 26.
(A) is a plan view, (B) is an XX sectional view of (A),
(C) is a YY sectional view of (A). Inner chip 26
The underside shape of the is stepped, the cross section is reverse tapered,
The impeller side plate 12a is also shaped accordingly.
There is some play between each other. Inner chip 2
6 and the upper surface of the impeller side plate 12a are flush with each other.

The inner chip 26 is formed by sintering a ceramic such as cemented carbide or silicon carbide, and all of them have excellent wear resistance. After the inner chip 26 is fitted into the impeller side plate, an adhesive is filled and fixed. Since the adhesive is used at room temperature and does not require heating or the like, the material of the inner chip 26 does not deteriorate.

FIG. 5 shows a detailed structure of the blade end tip 22. (A) is a plan view, (B) is an XX view of (A). The lower surface of the blade end tip 22 has a plurality of stepped shapes, and the blade 13 has a shape corresponding to the shape, and a certain amount of play is provided between the blades. The blade surface and the blade end tip surface are the same. The blade end tip 22 is made of a cemented carbide and has excellent wear resistance. After inserting the blade end tip 22 into the blade 13, an adhesive is filled and fixed. Since the adhesive is used at normal temperature and does not require heating or the like, the material of the blade end tip 22 does not deteriorate.

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

[0029]

As described above, in the concrete spraying machine of the present invention, friction-resistant fins are provided in the gap between the impeller side plate and the casing to prevent concrete from leaking from the gap and improve the durability of the fins. I was able to. Abrasion-resistant inner chips and blade end chips were provided on the blade mounting portion on the inner surface of the impeller side plate and on the blade end surface, respectively, so that wear was prevented and durability was improved. The mounting of the outer fin, the inner chip, and the blade end chip is not heat bonding to the base material but fitting and bonding with an adhesive, so that material deterioration can be prevented. An opening is provided at the base of the discharge pipe, air is drawn into the discharge pipe by discharge concrete, and an air layer is formed along the inner wall of the discharge pipe to reduce friction with concrete, so that the drop in concrete projection speed is reduced. And the projection performance is improved.

[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 detailed view of an outer fin.

FIG. 4 is a detailed view of an inner chip.

FIG. 5 is a detailed view of a blade end tip.

FIG. 6 is a schematic view of a conventional air blowing machine.

FIG. 7 is a configuration diagram of a head portion of a conventional concrete spraying machine that does not use air.

FIG. 8 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 13 Blade 13a Blade support 13b Bolt 14 Casing 16 Concrete supply pipe 18 Concrete discharge pipe 18a Inner end (scraper part) 20 Quick setting agent supply nozzle 22 Blade end tip 24 Outer fin 26 Inner tip 28 Discharge pipe opening

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. Abrasion-resistant fins are arranged on the outer peripheral edge of the impeller side plate at an interval and inclined with respect to the radial direction. 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 a rotation center of the impeller, and a concrete discharge pipe provided in the casing adjacent to the concrete supply pipe. Wherein the impeller has two impeller side plates spaced apart in the axial direction of the rotating shaft, and is radially attached to the impeller with a circumferential interval therebetween. Consisting of multiple blades,
A concrete spraying machine characterized in that an abrasion-resistant tip is mounted flush with a radially outer end of a surface of the blade that is in contact with concrete. 3. The concrete spraying machine according to claim 2, wherein an abrasion-resistant chip is mounted flush with the blade mounting position on the inner peripheral surface of the impeller side plate. 4. The concrete spraying machine according to claim 1, wherein a plurality of openings are provided at the base of the concrete discharge pipe.