Concrete mobile mixer

Abstract

To provide a mixer for a concrete mobile vehicle which can be mounted on a vehicle in a space-saving manner and has excellent mixing and delivery capabilities. [Solution] A plurality of internal screw blades 3 are fixed at predetermined intervals to the outer periphery of a shaft 2 housed inside a cylindrical casing 1 of the mixer body, while a plurality of external screw blades 5 are connected and fixed at predetermined intervals to the inside of an outer frame 4 that surrounds the outside of these internal screw blades 3 along the longitudinal direction of the casing 1, so that the internal screw blades 3 and the external screw blades 5 are arranged alternately in the discharge outlet direction, and the rotation direction of the connected body of the shaft 2 and internal screw blades 3 and the rotation direction of the connected body of the outer frame 4 and external screw blades 5 are reversed by a double rotation mechanism, thereby adopting a technical means for stirring and mixing the concrete material poured into the casing 1 and enabling it to be sent out in the discharge outlet direction.

Description

[Technical field]

[0001] The present invention relates to an improvement in construction machinery and equipment, and more particularly to a mixer for a concrete mobile vehicle which can be mounted on a vehicle in a space-saving manner and has excellent mixing and delivery capabilities. [Background technology]

[0002] When carrying out concrete work at a construction site or the like, ready mixed concrete hardens quickly, so a method is known in which ready mixed concrete produced in advance at a factory is transported while being stirred in a mixer truck as described in <Patent Document 1>.

[0003] Furthermore, ready-mix concrete can also be produced on-site using a concrete mobile vehicle (mobile concrete plant) such as that described in Patent Document 2, but this requires a mixer to be mounted on the mobile vehicle.

[0004] Typically, mixers are structured so that a helical screw is wound around the outer circumference of a shaft, and the concrete material is pumped out by rotating this shaft, but this does not provide sufficient stirring or mixing of the material.

[0005] Therefore, in order to mix the concrete materials more efficiently in the mixer, a twin-screw extruder structure is known that uses a counter-rotating mechanism in which multiple screws are provided and each shaft rotates in the opposite direction. However, since there are two shafts, the device becomes large and heavy, and there is a problem that it is not suitable for mounting on a vehicle. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2003-231115 A [Patent Document 2] JP 2008-80545 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above-mentioned problems in the prior art, and an object of the present invention is to provide a mixer for a concrete mobile vehicle that can be mounted on a vehicle in a space-saving manner and has excellent mixing and delivery capabilities. [Means for solving the problem]

[0008] The means adopted by the present inventor to solve the above technical problems will be described below with reference to the accompanying drawings.

[0009] That is, the present invention is a mixer for mixing concrete mounted on the rear of a concrete mobile vehicle, A plurality of internal screw blades 3 are fixed at predetermined intervals on the outer periphery of a shaft 2 housed inside a cylindrical casing 1 of the mixer body. Along the longitudinal direction of the casing 1, a plurality of outer screw blades 5 are connected and fixed at a predetermined interval inside an outer frame 4 that surrounds the outside of the inner screw blades 3, The inner screw blades 3 and the outer screw blades 5 are arranged alternately in the discharge port direction, and the rotation direction of the connected body of the shaft 2 and the inner screw blades 3 and the rotation direction of the connected body of the outer frame 4 and the outer screw blades 5 are reversed by a counter-rotating mechanism. By adopting a technical means that enables the concrete materials put inside the casing 1 to be stirred and mixed and then discharged in the direction of the discharge outlet, a mixer for a concrete mobile vehicle has been completed.

[0010] In addition, in order to solve the above problems, the present invention can also adopt, in addition to the above means as necessary, a technical means in which the outer peripheral surface of the outer frame 4 and the inner peripheral surface of the casing 1 are brought into close proximity with each other, so that the concrete material between the outer frame 4 and the inner peripheral surface of the casing 1 can be discharged in the direction of the discharge outlet by rotating the outer frame 4.

[0011] Furthermore, in order to solve the above problems, the present invention can employ, in addition to the above means, a technical means in which the outer frame 4 is curved in a spiral shape with respect to the discharge port direction, if necessary.

[0012] Furthermore, in order to solve the above problems, the present invention can also adopt, in addition to the above means, a technical measure of fixing the outer frame 4 along the outer peripheral edge of the outer screw blade 5, if necessary.

[0013] Furthermore, in order to solve the above problems, the present invention can also adopt, in addition to the above means, a technical measure of providing a gap 6 between the end edge of the internal screw blade 3 and the end edge of the external screw blade 5 to prevent concrete material from getting caught, if necessary.

[0014] Furthermore, in order to solve the above problems, the present invention can also adopt, in addition to the above means, a technical measure in which the internal screw blade 3 is a spiral plate body that extends around the outer circumference of the shaft 2, as necessary.

[0015] Furthermore, in order to solve the above problems, the present invention can also adopt, in addition to the above means, a technical measure in which the outer screw blade 5 is a spiral plate body that extends around the inner side of the outer frame 4 once, as necessary. Effect of the Invention

[0016] In the present invention, a counter-rotating screw mechanism is used, so that while the concrete flows in the same direction, every other blade of the screw rotates in the opposite direction, providing excellent mixing capabilities and improving the mixing of the concrete materials inside the mixer.

[0017] In addition, the high mixing capacity improves mixing, so the overall length of the device can be shortened, making it space-saving and suitable for mounting on a vehicle.

[0018] Furthermore, since the counter-rotating mechanism requires only a single coaxial shaft, the device can be made compact and lightweight, and its shape can be made suitable for mounting on a vehicle, making the device highly valuable in industrial applications. [Brief description of the drawings]

[0019] [Figure 1] 1 is an overall schematic diagram showing a concrete mobile vehicle equipped with a mixer according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram illustrating an internal structure of a mixer according to an embodiment of the present invention. [Diagram 3] FIG. 11 is an explanatory diagram illustrating a modified example of the mixer according to the embodiment of the present invention. [Figure 4] FIG. 11 is an explanatory diagram illustrating an internal structure of a modified example of the mixer according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] An embodiment of the present invention will be described with reference to Figs. 1 to 4 (in some cases, the illustration of the casing 1 is omitted and only the internal structure of the mixer is shown). The present invention is a mixer for mixing concrete that is mounted on the rear of a concrete mobile vehicle (see Fig. 1). A concrete mobile vehicle, also known as a mobile concrete batch plant, is a vehicle for producing concrete on-site. These vehicles are equipped with storage tanks for cement, aggregates (water, gravel, etc.), water, and admixtures, and mix these materials in the appropriate ratios on-site.

[0021] In constructing the present invention, first, a plurality of internal screw blades 3 are fixed at a predetermined interval to the outer periphery of a shaft 2 housed inside a cylindrical casing 1 of the mixer body. As a specific example of the size, the shaft 2 has a diameter of 50 mm, a total length of 1800 mm, and a diameter of the internal screw blade 3 of 250 mm.

[0022] In this embodiment, the casing 1 is cylindrical, and the shaft 2 is disposed in the center of the cylinder in the longitudinal direction. The multiple internal screw blades 3 are composed of plates having helically curved surfaces, and are configured to move materials or fluids by utilizing rotational motion (extrusion structure). From the viewpoints of strength and cost, the shaft 2 and the internal screw blades 3 are generally made of steel material, and are preferably fixed by welding.

[0023] Next, a plurality of external screw blades 5 are connected and fixed at a predetermined interval inside an outer frame 4 that surrounds the outside of the internal screw blade 3 along the longitudinal direction of the casing 1. The plurality of external screw blades 5 are composed of a plate body having a helical curved surface (usually a helical plate body shape symmetrical to the internal screw blade 3), and move materials or fluids by utilizing a rotational motion, similar to the internal screw blade 3. As a specific example of the size, the diameter of the external screw blade 5 is 250 mm. Moreover, from the viewpoints of strength and cost, the internal screw blade 3 and the external frame 4 are also usually made of a steel material and are preferably fixed by welding.

[0024] In this embodiment, the shape of the outer frame 4 may be a straight rod as shown in Fig. 2, a curved rod as shown in Fig. 3, or a spiral as shown in Fig. 4. The inner edge of the outer screw blade 5 may be disposed close to the outer circumferential surface of the shaft 2 with a gap of about several centimeters between it and the outer circumferential surface, making it difficult for aggregate to be caught in the gap and preventing loss of the concrete material due to retention.

[0025] The inner screw blades 3 and the outer screw blades 5 are arranged alternately in the discharge port direction.

[0026] Furthermore, the rotation direction of the connected body of the shaft 2 and the inner screw blade 3 and the rotation direction of the connected body of the outer frame 4 and the outer screw blade 5 are configured to rotate coaxially in forward and reverse directions by a counter-rotating mechanism (the arrows in Figure 3 indicate the rotation directions of the screws). The "counter-rotating mechanism" is a structure in which two screws are attached to the same shaft and driven to rotate in opposite directions.

[0027] The shaft 2 is composed of an inner shaft and an outer shaft with the same rotation axis, and a cylindrical outer shaft is disposed outside the inner shaft, and the inner shaft and the outer shaft rotate in opposite directions. In this embodiment, the inner screw blade 3 is joined to the inner shaft of the shaft 2, and the outer screw blade 5 is joined to a joint 51 of the outer shaft, and the rotation of the outer screw blade 5 is also transmitted to the outer frame 4, so that the other connected outer screw blades 5 can also be rotated.

[0028] By adopting a counter-rotating mechanism, it is possible to improve efficiency by offsetting the counter torque generated by the screw. In addition, the concrete material moves in a complex manner inside the casing 1, improving the stirring and mixing effect. Since the inner screw blade 3 and the outer screw blade 5 are symmetrical spiral plate shapes, the concrete material is discharged in the same direction even if they rotate in opposite directions.

[0029] The concrete material put into the inside of the casing 1 can be agitated and mixed and sent out in the direction of the discharge port. In this embodiment, the rotation speed of the screw is preferably about 60 rpm.

[0030] In this embodiment, the inner screw blade 3 can be a helical plate that extends one revolution around the outside of the shaft 2, and the outer screw blade 5 can be a helical plate that extends one revolution around the inside of the outer frame 4. This allows the rotation phases of the adjacent outer screw blades 5 to match, making it difficult for aggregate to be pinched, and also preventing loss of the concrete material due to retention.

[0031] In addition, in this embodiment, the outer peripheral surface of the outer frame 4 and the inner peripheral surface of the casing 1 are brought into close proximity (about a few centimeters in this embodiment), and by rotating the outer frame 4, the concrete material between the outer frame 4 and the inner peripheral surface of the casing 1 can be discharged in the direction of the discharge outlet.

[0032] Furthermore, in this embodiment, the outer frame 4 can be curved spirally in the discharge outlet direction (see Figures 3 and 4), and by rotating the outer frame 4, the concrete material between the outer frame 4 and the inner surface of the casing 1 can be discharged in the discharge outlet direction, preventing loss of the discharge amount.

[0033] Furthermore, in this embodiment, as shown in Fig. 4, the outer frame 4 can be fixed along the outer peripheral edge of the outer screw blade 5, and loss of the concrete material discharged can be prevented by minimizing the gap between the outer peripheral edge of the outer screw blade 5 and the inner peripheral surface of the casing 1. The outer frame 4 and the outer screw blade 5 may be fixed, for example, with a clip-shaped jig or by welding.

[0034] In addition, in this embodiment, a gap 6 can be provided between the edge of the inner screw blade 3 and the edge of the outer screw blade 5 to prevent concrete material from getting caught, thereby reducing the load on the mixer and preventing breakdowns.

[0035] The present invention is generally configured as described above, however, the present invention is by no means limited to the illustrated embodiment, and various modifications are possible within the scope of the claims. For example, the shape, number, spacing, material, etc. of the internal screw blades 3 and the external screw blades 5 can be modified as appropriate and fall within the technical scope of the present invention. [Explanation of symbols]

[0036] 1 Casing 2 Shaft 3 Inner screw blade 4 Outer frame 5 Outer screw blade 51 Joint 6 Gap V Vehicle

Claims

1. A mixer for mixing concrete mounted on the rear of a concrete mobile vehicle, A plurality of internal screw blades are fixed at predetermined intervals on the outer periphery of a shaft housed inside a cylindrical casing of the mixer body. Along the longitudinal direction of the casing, a plurality of outer screw blades are connected and fixed at predetermined intervals to the inside of an outer frame that surrounds the outside of the inner screw blades, the internal screw blades and the external screw blades are arranged alternately in a discharge port direction, and a rotation direction of a connected body of the shaft and the internal screw blades and a rotation direction of the connected body of the outer frame and the external screw blades are configured to rotate in opposite directions by a counter-rotating mechanism; A mixer for a concrete mobile vehicle, characterized in that concrete materials fed into the inside of the casing are agitated and mixed and can be discharged in the direction of the discharge outlet.

2. A mixer for a concrete mobile vehicle as described in claim 1, characterized in that the outer peripheral surface of the outer frame and the inner peripheral surface of the casing are close to each other, and by rotating the outer frame, the concrete material between the outer frame and the inner peripheral surface of the casing can be discharged in the direction of the discharge outlet.

3. 2. A mixer for a concrete mobile vehicle according to claim 1, wherein the outer frame is curved in a spiral shape relative to the discharge port direction.

4. 4. A mixer for a concrete mobile vehicle according to claim 3, wherein the outer frame is fixed along the outer periphery of the outer screw blade.

5. 2. A mixer for a concrete mobile vehicle according to claim 1, characterized in that a gap is provided between the end edge of the inner screw blade and the end edge of the outer screw blade to prevent concrete material from getting caught.

6. 2. A mixer for a concrete mobile vehicle according to claim 1, wherein said inner screw blade is a spiral plate that extends around the outer circumference of the shaft.

7. 2. A mixer for a concrete mobile vehicle according to claim 1, wherein the outer screw blade is a spiral plate that extends around the inside of the outer frame.

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