Concrete mixer for mobile concrete vehicles

Abstract

To provide a concrete mobile mixer that can be mounted on a vehicle in a space-saving manner and has excellent mixing and dispensing capabilities. [Solution] A technical means was employed to enable the concrete material introduced into the casing 1 to be stirred and mixed and discharged towards the discharge port by configuring the following: Multiple internal screw blades 3 are fixed at predetermined intervals around the outer circumference of a shaft 2 housed inside a cylindrical casing 1 of the mixer body, while multiple external screw blades 5 are connected and fixed at predetermined intervals inside an outer frame 4 that surrounds the outside of these internal screw blades 3 along the longitudinal direction of the casing 1, thereby arranging the internal screw blades 3 and external screw blades 5 alternately in the direction of the discharge port, and configuring the rotation direction of the connection between the shaft 2 and internal screw blades 3 and the rotation direction of the connection between the outer frame 4 and external screw blades 5 to rotate in opposite directions by a dual reversal mechanism.

Description

Technical Field

[0001] The present invention relates to an improvement of construction machinery, and more particularly to a mixer for a concrete mobile vehicle that can be mounted on a vehicle in a space-saving manner and has excellent stirring ability and feeding ability.

Background Art

[0002] When performing concrete work at a construction site or the like, since fresh concrete hardens quickly, a method of transporting fresh concrete manufactured in a factory in advance while stirring it with a mixer truck such as <Patent Document 1> is known.

[0003] Also, fresh concrete may be manufactured on site by a concrete mobile vehicle (mobile concrete plant) such as <Patent Document 2>, but for this purpose, it is necessary to mount a mixer on the mobile vehicle.

[0004] Normally, the structure of the mixer is such that a spiral screw is wound around the outer periphery of a shaft, and by rotating this shaft, the concrete material is configured to be sent out, but the stirring and mixing of the material are not very sufficient.

[0005] Therefore, in order to mix the concrete material more efficiently in the mixer, a two-shaft extrusion mechanism structure that employs a double reversal mechanism in which a plurality of screws are provided and each shaft rotates in the reverse direction is also known. However, since there are two shafts, there is a problem that the device becomes large and heavy and is not suitable for vehicle mounting.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

[0007] This invention was made in view of the problems with the prior art described above, and its objective is to provide a concrete mobile mixer that can be mounted on a vehicle in a space-saving manner and has excellent mixing and dispensing capabilities. [Means for solving the problem]

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

[0009] In other words, the present invention is a concrete mixer mounted at the rear of a concrete mobile vehicle, Multiple internal screw blades 3 are fixed at predetermined intervals to the outer circumference of the shaft 2 housed inside the cylindrical casing 1 of the mixer body, Along the longitudinal direction of the casing 1, a plurality of external screw blades 5 are connected and fixed at predetermined intervals inside the outer frame 4 that surrounds the outside of these internal screw blades 3. The internal screw blades 3 and external screw blades 5 are arranged alternately in the direction of the discharge port, and the rotation direction of the connecting body of the shaft 2 and internal screw blades 3 and the rotation direction of the connecting body of the external frame 4 and external screw blades 5 are configured to rotate in opposite directions by a dual counter-rotating mechanism. By employing a technical means that allows the concrete material placed inside the casing 1 to be stirred and mixed and then discharged towards the outlet, a concrete mobile mixer was completed.

[0010] Furthermore, in order to solve the above problems, the present invention may also employ, if necessary, a technical means to bring the outer circumferential surface of the outer frame 4 and the inner circumferential surface of the casing 1 into close proximity, so that the concrete material between the outer frame 4 and the inner circumferential surface of the casing 1 can be discharged toward the discharge port by the rotation of the outer frame 4.

[0011] Furthermore, in order to solve the above problems, the present invention may also employ, if necessary, a technical means of curving the outer frame 4 spirally with respect to the discharge port direction, in addition to the above means.

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

[0013] Furthermore, in order to solve the above problems, the present invention may also employ, if necessary, a technical means of providing a gap 6 between the edge of the inner screw blade 3 and the edge of the outer screw blade 5 to prevent concrete material from getting stuck.

[0014] Furthermore, in order to solve the above problems, the present invention may also employ, if necessary, a technical means of making the internal screw blade 3 a helical plate body that covers one full circumference of the outside of the shaft 2, in addition to the above means.

[0015] Furthermore, in order to solve the above problems, the present invention may also employ, if necessary, a technical means of making the external screw blade 5 a helical plate body that covers one full circumference inside the outer frame 4, in addition to the above means. [Effects of the Invention]

[0016] In this invention, by employing a dual counter-rotating mechanism in the screw, the direction of concrete flow remains the same, but every other blade of the screw rotates in the opposite direction, resulting in excellent mixing ability and better mixing of concrete materials within the mixer.

[0017] In addition, due to its high stirring ability, the mixing becomes better, and the overall length of the device can be shortened, resulting in a space-saving shape suitable for vehicle mounting.

[0018] Furthermore, since the shaft with a double inversion mechanism only requires one coaxial shaft, the device can be made compact and lightweight, and can be shaped suitable for vehicle mounting. Therefore, there is a quite high industrial utility value.

Brief Description of the Drawings

[0019] [Figure 1] It is an overall schematic diagram showing a concrete mobile vehicle equipped with the mixer according to an embodiment of the present invention. [Figure 2] It is an explanatory diagram showing the internal structure of the mixer according to an embodiment of the present invention. [Figure 3] It is an explanatory diagram showing a modification example of the mixer according to an embodiment of the present invention. [Figure 4] It is an explanatory diagram showing the internal structure of a modification example of the mixer according to an embodiment of the present invention.

Modes for Carrying Out the Invention

[0020] Embodiments of the present invention will be described based on FIGS. 1 to 4 (in some cases, the description of the casing 1 may be omitted and only the internal structure of the mixer is shown). The present invention is a mixer for concrete mixing mounted on the rear of a concrete mobile vehicle (see FIG. 1). A concrete mobile vehicle, also called a mobile concrete batch plant, is a vehicle for manufacturing concrete at the site. These vehicles are equipped with storage tanks for cement, aggregates (such as water and gravel), water, and admixtures, and mix these materials at appropriate ratios at the site.

[0021] In constructing the present invention, first, a plurality of internal screw blades 3 are fixed at predetermined intervals to the outer circumference of a shaft 2 housed inside a cylindrical casing 1 of the mixer body. Specific examples of the dimensions include a shaft 2 with a diameter of 50 mm and a total length of 1800 mm, and internal screw blades 3 with a diameter of 250 mm.

[0022] In this embodiment, the casing 1 is cylindrical, and a shaft 2 is arranged longitudinally at the center of the cylinder. The multiple internal screw blades 3 are made of plates having a helical curved surface and move materials or fluids using rotational motion (extrusion structure). From the viewpoint of strength and cost, the shaft 2 and internal screw blades 3 are usually made of steel and preferably fixed by welding.

[0023] Next, along the longitudinal direction of the casing 1, multiple external screw blades 5 are connected and fixed at predetermined intervals inside the outer frame 4 that surrounds the outside of the internal screw blades 3. The multiple external screw blades 5 are made of plates with a helical curved surface (usually a helical plate shape symmetrical to the internal screw blades 3), and, like the internal screw blades 3, they use rotational motion to move materials or fluids. A specific example of the size is that the diameter of the external screw blades 5 is 250 mm. Furthermore, from the viewpoint of strength and cost, it is preferable that the internal screw blades 3 and the outer frame 4 are usually made of steel and fixed by welding.

[0024] In this embodiment, the shape of the outer frame 4 can be a straight rod shape as shown in Figure 2, a curved rod shape as shown in Figure 3, or a spiral shape as shown in Figure 4. Furthermore, the inner edge of the outer screw blade 5 can be positioned close to the outer surface of the shaft 2 with a gap of several centimeters between them, which makes it difficult for aggregate to get stuck in this gap and also prevents loss of the amount of concrete material being delivered due to stagnation.

[0025] The internal screw blades 3 and the external screw blades 5 are then arranged alternately in the direction of the discharge port.

[0026] Furthermore, the rotation direction of the connection between the shaft 2 and the internal screw blade 3, and the rotation direction of the connection between the outer frame 4 and the external screw blade 5 are configured to rotate coaxially in forward and reverse directions by a dual counter-rotating mechanism (the arrows in Figure 3 indicate the rotation direction of the screw). A "dual counter-rotating mechanism" is a structure in which two screws are mounted on the same axis and driven to rotate in opposite directions.

[0027] The shaft 2 consists of an inner shaft and an outer shaft with the same axis of rotation, and a cylindrical outer shaft is disposed outside the inner shaft, with the inner and outer shafts rotating 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 the joint portion 51 of the outer shaft, so that the rotation of the outer screw blade 5 is transmitted to the outer frame 4, and the other connected outer screw blades 5 can also be rotated.

[0028] By employing a dual counter-rotating mechanism, the counter-torque generated by the screw can be offset, thereby improving efficiency. Furthermore, the complex movement of the concrete material inside the casing 1 improves the agitation and mixing effect. Since the inner screw blades 3 and outer screw blades 5 have symmetrical helical plate shapes, even when they rotate in opposite directions, the direction in which the concrete material is discharged remains the same.

[0029] The concrete material introduced into the casing 1 is then agitated and mixed, and can be discharged towards the discharge port. In this embodiment, the screw rotation speed is preferably around 60 rpm.

[0030] In this embodiment, the internal screw blade 3 can be made into a helical plate body that covers one full circumference of the outside of the shaft 2, and furthermore, the external screw blade 5 can be made into a helical plate body that covers one full circumference of the inside of the outer frame 4. By doing so, the rotational phases of adjacent external screw blades 5 are aligned, making it less likely for aggregate to get caught, and also preventing loss of the amount of concrete material being delivered due to stagnation.

[0031] Furthermore, in this embodiment, by bringing the outer circumferential surface of the outer frame 4 and the inner circumferential surface of the casing 1 close together (by a few centimeters in this embodiment), the concrete material between the outer frame 4 and the inner circumferential surface of the casing 1 can be discharged towards the discharge port by rotating the outer frame 4.

[0032] Furthermore, in this embodiment, the outer frame 4 can be curved spirally with respect to the discharge port direction (see Figures 3 and 4), and the rotation of the outer frame 4 allows the concrete material between the outer frame 4 and the inner circumferential surface of the casing 1 to be discharged in the direction of the discharge port, thereby preventing loss of discharge volume.

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

[0034] Furthermore, 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 stuck, thereby reducing the load on the mixer and preventing malfunctions.

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

[0036] 1 Casing 2 shafts 3. Internal screw blades 4 Outer frame 5. External screw blades 51 Joint 6 Gap V Vehicle

Claims

1. A concrete mixer mounted at the rear of a concrete mobile vehicle, Multiple internal screw blades are fixed at predetermined intervals around the outer circumference of the shaft housed inside the cylindrical casing of the mixer body, Along the longitudinal direction of the casing, a plurality of external screw blades are connected and fixed at predetermined intervals inside the outer frame that surrounds the outside of these internal screw blades. The internal and external screw blades are arranged alternately in the direction of the discharge port, and the rotation direction of the connector between the shaft and the internal screw blades and the rotation direction of the connector between the external frame and the external screw blades are configured to rotate in opposite directions by a dual counter-rotating mechanism. A concrete mobile mixer characterized in that the concrete material put inside the casing is agitated and mixed and can be discharged toward the discharge port.

2. The concrete mobile mixer according to claim 1, characterized in that the outer surface of the outer frame and the inner surface of the casing are in close proximity, and the concrete material between the outer frame and the inner surface of the casing can be discharged in the direction of the discharge port by the rotation of the outer frame.

3. The concrete mobile mixer according to claim 1, characterized in that the outer frame is curved spirally with respect to the discharge direction.

4. The concrete mobile mixer according to claim 3, characterized in that the outer frame is fixed along the outer edge of the outer screw blades.

5. The concrete mobile mixer according to claim 1, characterized in that a gap is provided between the edge of the inner screw blade and the edge of the outer screw blade to prevent concrete material from getting stuck.

6. The concrete mobile mixer according to claim 1, characterized in that the internal screw blades are spiral plates that make up one full rotation of the outside of the shaft.

7. The concrete mobile mixer according to claim 1, characterized in that the external screw blades are spiral plates that make up one full rotation inside the outer frame.

Images