JP4958685B2 - Mixer - Google Patents

Description

  The present invention relates to a mixer that stirs and mixes various mixed materials, and particularly relates to a mixer that is excellent in maintainability.

  Conventionally, for example, horizontal axis mixers as shown in Patent Documents 1 to 3 are well known as mixers installed in ready-mixed concrete manufacturing plants. This type of mixer is equipped with a mixing tank into which various materials such as gravel, sand, cement, water, admixture, etc. are charged, and the mixing axis is horizontally penetrated into the mixing tank to rotatably support the mixing tank. A mixing blade is attached to the tip of an arm arranged radially in the radial direction of the shaft.

In addition, a dust cover is placed on the upper part of the mixing tank to prevent mixing of various materials discharged from the weighing tank above the mixer into the mixing tank. The inside of the tank is in a substantially sealed state, and the side wall portion of the cover body is provided with an inspection door that can be opened and closed as described in Patent Documents 1 to 3, and an operator can open the inspection door. Various maintenance operations such as cleaning inside the mixer, replacing parts, or repairing are performed.
JP-A-5-115767 JP-A-6-55526 JP 7-52142 A

  By the way, the size of the inspection door is naturally more convenient in consideration of workability, but since it is restricted by the width of the cover body side wall on the installation side, conventionally, as shown in FIGS. As shown in the figure, only a relatively small inspection door 10 'can be used, and its installation position is restricted by the height of the side wall 2a of the mixing tank 2, so that it can be installed only at a relatively high position from the lower end of the mixer 1'. There wasn't.

  Therefore, the workability of the various maintenance operations for the mixer 1 'performed by the worker through the inspection door 10' is not so good. In particular, when the worker needs to perform the work in the mixer 1 ', the worker performs the inspection. It has been difficult to enter and exit the mixer 1 'many times through the door 10', and the work efficiency is never good, and there is room for improvement. In addition, although the method of extending the inspection door by extending the side wall 8a of the cover body 8 on the installation side, for example, is considered, there are many cases where only the mixer 1 'is replaced in an existing plant. Since the positional relationship between the mixer 1 'and the upper weighing tank (not shown) cannot be changed, it is difficult to adopt a standard mixer to extend the cover body side wall 8a upward.

  In view of the above-described points, an object of the present invention is to provide a mixer that is easy to perform maintenance work by allowing a large inspection door to be used for the mixer.

In order to solve the above-mentioned problems, in the mixer according to claim 1 according to the present invention, the mixing shaft is penetrated horizontally through the mixing tank and rotatably supported, and the mixing blade is attached to the mixing shaft. In a mixer installed in a ready-mixed concrete production plant in which a dustproof cover body is disposed at the upper part of the mixing tank, the side wall parallel to the mixing axis of the mixing tank is positioned at the tip of the mixing blade rather than the side wall on the bearing side. The mixed material is dropped downward to a predetermined height that does not come in contact with the rotation locus to form a step, while the cover body side wall on the side of the mixing tank side parallel to the mixing axis is formed by the amount of the step. Extending downward to widen the area of the cover body side wall, the cover body side wall is provided with a large inspection door having a height increased in size by the downward extension and a width of the size over substantially the entire width of the side wall, the inspection door is the upper end Together axially supports the bar body side wall and pivotally opened and closed in the vertical direction, it is characterized by comprising biasing means for biasing the access door in the opening direction.

The mixer according to claim 2 is characterized in that the biasing means is a gas spring .

According to the mixer of the first aspect of the present invention, the mixing shaft is horizontally penetrated through the mixing tank and is rotatably supported. The mixing shaft is attached to the mixing shaft, and the dust tank is disposed above the mixing tank. In a mixer installed in a ready-mixed concrete production plant having a cover body for the mixing, the side wall parallel to the mixing axis of the mixing tank is moved away from the rotation trajectory of the mixing blade tip than the side wall on the bearing side. A step is formed by dropping the material downward to a predetermined height at which the material does not come into contact, while extending the cover body side wall on the side of the mixing vessel side parallel to the mixing axis downward by the amount of the step. spread area of the side wall, with the height of the size in the cover member side wall increases extended amount of downward, a large access door and a width of a size over substantially the entire width of the side wall, the inspection door its upper end On the side wall of the cover body In addition to being able to pivot open and close in the direction, and equipped with a biasing means that biases the inspection door in the opening direction, the inspection door can be increased in size and the workability is very good, and the worker can be moved to the mixer. As a result, the mixer is much easier to enter and exit, and a suitable mixer that can be easily maintained can be obtained. In addition, the inspection door can be easily opened and closed by the biasing means, which can greatly reduce the burden on the worker, prevent the door from closing suddenly during the closing operation, prevent breakdown and damage, and work safety. Also excellent.

Further, according to the mixer of the second aspect, since the gas spring is employed as the biasing means, it is not necessary to supply the pressure medium, the maintenance is facilitated, and the apparatus cost and running cost can be kept low. The

  In the mixer according to the present invention, among the side walls of the mixing tank, the side wall parallel to the mixing axis is dropped below the side wall on the bearing side by a predetermined height to form a step, while the mixing axis The side wall of the cover body located at the upper part of the side wall parallel to the side is extended downward by the step, thereby increasing the area of the cover body side wall.

  The vicinity of the upper end of the mixing vessel side wall on the side parallel to the mixing axis is out of the rotation trajectory of the mixing blade and does not come into contact with the mixture, so that the side wall of the cover body is moved downward as described above. Even if it is extended, there is no problem in wear. Then, the cover side wall having an enlarged area is provided with a large inspection door over a substantially entire width at a relatively low position from the lower end of the mixer, and the upper end of the inspection door is pivotally supported by the cover side wall to move up and down. A gas spring is provided as a biasing means for biasing the inspection door in the opening direction on both sides thereof.

  When the worker performs operations such as cleaning the inside of the mixer from the outside of the mixer, or when performing operations such as parts replacement or repair by entering the mixer, the inspection door is opened. At this time, since the inspection door has a size covering almost the entire width of the side wall of the cover body and is provided at a relatively low position, the workability is very good, and the worker can go in and out of the mixer. It is easy and a great improvement in work efficiency can be expected.

  On the other hand, as the inspection door becomes larger, there is a concern that the weight increases and it becomes difficult to handle, but the inspection door is equipped with a gas spring to urge the inspection door in the opening direction, so it is relatively small. It is possible to easily open and close even with force, greatly reducing the burden on the worker and preventing the sudden closing operation of the inspection door during the closing operation, which is also effective in terms of work safety.

  In this way, the mixing tank side wall on the side parallel to the mixing axis of the mixer is dropped to a predetermined height below the side wall on the bearing side to form a step, and the cover side wall is extended downward by the amount of the step. Since the cover body side wall area is widened and a large inspection door is provided over substantially the entire width of the cover body side wall, the mixer is easy to perform maintenance work that allows workers to easily enter and exit the mixer. Further, if the inspection door is provided with a biasing means for biasing in the opening direction, for example, a gas spring, it can be opened and closed easily and safely regardless of the size and weight of the inspection door.

  Embodiments of the present invention will be described below with reference to FIGS.

  Reference numeral 1 in the figure denotes a biaxial mixer installed in a ready-mixed concrete production plant or the like, which can freely rotate through two parallel horizontal mixing shafts 3 in a mixing tank 2 composed of two twin bodies. A mixing blade 5 is attached to the tip of a large number of arms 4 arranged radially on the mixing shaft 3. Reference numeral 6 denotes a driving motor for rotationally driving the mixing shaft 3, and a speed reducer 7 for reducing the rotational speed of the driving motor 6 and transmitting it to the mixing shaft 3 is disposed below the driving motor 6.

  In addition, a dust-proof cover body 8 is provided at the upper part of the mixing tank 2 so that the inside of the mixing tank 2 is substantially sealed, and a metering tank (not shown) above the mixer 1 is inserted through a charging chute 9. A part of the various materials to be introduced is designed not to be scattered around the mixer 1, and an inspection door 10 is provided on the side wall portion of the cover body 8 so as to be freely opened and closed, and mixed through the inspection door 10. Various maintenance operations such as cleaning the inside of the tank 2, replacing parts, or repairing are possible.

  Of the side walls of the mixing tank 2, the side wall 2a on the side parallel to the mixing shaft 3 is dropped to a predetermined height, for example, about 300 mm below the side wall 2b on the bearing side, and a step as shown in the drawing is formed. It is formed. And the area of the cover body side wall 8a is expanded by extending the side wall 8a of the cover body 8 located in the upper part of this mixing tank side wall 2a downward by the said level | step difference over the full length. At this time, the vicinity of the upper end portion of the mixing vessel side wall 2a on the side parallel to the mixing shaft 3 is out of the rotation locus of the tip of the mixing blade 5 rotating around the mixing shaft 3, and the mixed material does not come into contact therewith. As described above, there is no problem in wear even if the structure is slightly lowered downward.

  In addition, as shown in FIG. 2, both ends of the side wall 8b of the cover body 8 located above the mixing tank side wall 2b on the bearing side are also extended downward. The part need not be extended.

  Then, the cover body side wall 8a having an expanded area is formed to have a size that covers almost the entire width, for example, a width of about 2000 mm and a height of about 750 mm so that a worker can easily go in and out. The inspection door 10 is provided at a relatively low position of about 1400 mm from the lower end portion of the mixer 1, and the upper end portion of the inspection door 10 is pivotally supported by the cover body side wall 8a so that it can be freely opened and closed vertically. Both ends are provided with a pair of gas springs 11 that are urging means for urging the inspection door 10 in the opening direction. Reference numeral 12 denotes a support piece that is fixedly supported so as not to be closed by being hung on the inspection door 10 in an open state.

  4 and 5, the conventional inspection door 10 ′ is provided at a relatively high position of about 1750 mm from the lower end of the mixer 1 ′, and has a width of about 750 mm and a height of about 500 mm. Compared with the inspection door 10 ', the inspection door 10 is very large and has a very good workability, and the worker can easily enter and leave the mixer 1. In addition, as an opening / closing structure of the inspection door 10, for example, one side portion is pivotally supported so that it can be freely opened and closed left and right, or the inspection door itself can be configured to be detachable. In consideration of the required space, workability, and the like, it is preferable to configure such that it can be opened and closed in the vertical direction as in this embodiment.

  Further, the gas spring 11 as the urging means is for assisting the opening / closing operation of the inspection door 10 which may be difficult to handle due to an increase in size and weight, for example, as in this embodiment. In the case of the inspection door 10 having a width of about 2000 mm and a height of about 750 mm, the weight may be about 85 kg, but by providing the gas spring 11 as an urging means, the opening operation of the inspection door 10 is performed. In some cases, the worker can operate very easily with a relatively small force, and the burden on the worker can be greatly reduced. On the other hand, even during the closing operation, the rapid closing operation of the inspection door 10 can be suppressed and the apparatus can be operated. In addition to preventing breakdowns and damages, it also prevents accidents such as being caught between workers, leading to excellent work safety.

  In addition, since the size and weight of the inspection door 10 provided on the upper cover body side wall 8a change depending on the size of the mixer 1, the gas spring 11 may be appropriately selected in consideration of the balance at the time of opening and closing operations. . In addition to the gas spring employed in this embodiment, for example, a hydraulic cylinder or an air cylinder can be effectively employed as the biasing means. Maintenance is also easy, and it is possible to keep the device cost and running cost low, making it relatively easy to adopt.

  Further, as shown in FIG. 3, when the inspection door 10 is opened, a large opening formed in the cover body side wall 8a is detachably provided with a handrail material 13, so that an operator can connect from outside the mixer 1. When performing maintenance work, the handrail material 13 is latched in the retaining grooves 14 provided on both sides of the inspection door 10, while the handrail material 13 is only required when an operator needs to enter and exit the mixing tank 2 of the mixer 1. The safety of work is improved by removing.

  For safety, the cover body side wall 8a is provided with a limit switch 15 that stops the drive motor 6 according to the opening operation of the inspection door 10 and forcibly locks the rotation of the mixing shaft 3. This is intended to prevent other workers from rotating the mixing shaft 3 during maintenance work. On the other hand, the latching groove 14 for latching the handrail material 13 is provided with a limit switch 16 for unlocking the rotation of the mixing shaft 3 according to the latching of the handrail material 13, and In the vicinity, a start switch 17 of the drive motor 6 is provided. Only when the handrail material 13 is hooked in the stop groove 14 and the handrail is provided, the drive switch 6 is driven during the pressing operation of the start switch 17. The motor 6 is activated so that the mixing shaft 3 rotates. By doing so, for example, when a worker holds a cleaning hose or the like and cleans the mixing shaft 3, arm 4, mixing blade 5, etc. from outside the mixer 1, the mixing shaft 3 is moved little by little. By carrying out the rotation, it is possible to perform a good cleaning operation with little leftovers.

  Then, when a plant worker performs cleaning of the mixing tank 2 or replacement of the mixing blade 5 from outside the mixer 1, or when entering a mixing tank 2 of the mixer 1 to perform liner replacement or repair work. The operator rotates the inspection door 10 upward to open it. At this time, the operator can easily open the inspection door 10 with a relatively small force by the gas spring 11 that urges the inspection door 10 in the opening direction. Then, with the inspection door 10 opened, the support piece 12 is hung and fixedly supported, and the worker performs various maintenance operations through the opening that is largely open on the cover body side wall 8a. At this time, the inspection door 10 is not only large enough to cover almost the entire width of the cover body side wall 8a, but is also formed large toward the lower side of the mixing tank 2, so that the conventional inspection door and In comparison, the workability is very good, and the entry and exit of the operator to the mixer 1 is much easier.

  In this way, the mixing tank side wall 2a on the side parallel to the mixing shaft 3 of the mixer 1 is dropped below a predetermined height below the side wall 2b on the bearing side to form a step, and the cover side wall 8a is formed by the amount corresponding to the step. Since the cover body side wall area is extended by extending downward, it is possible to install a large inspection door 10 over almost the entire width of the cover body side wall 8a, and maintenance work that allows workers to easily enter and exit the mixer 1 can be performed. It becomes a suitable mixer which is easy to do. In addition, since the inspection door 10 is provided with an urging means for urging in the opening direction, it can be opened and closed easily and safely regardless of the size and weight of the inspection door 10, and a suitable mixer excellent in workability and Become. At this time, for example, if the gas spring 11 is employed as the urging means, maintenance is facilitated, and the apparatus cost, running cost, and the like can be kept low.

It is a front view which shows one Example of the mixer based on this invention. It is a side view of FIG. It is a figure equivalent to FIG. 1 of the state which opened the inspection door. It is a front view of the conventional mixer. FIG. 5 is a side view of FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mixer 2 ... Mixing tank 2a, 2b ... Mixing tank side wall 3 ... Mixing shaft 4 ... Arm 5 ... Mixing blade 6 ... Drive motor 7 ... Reduction gear 8 ... Cover body 8a, 8b ... Cover body side wall 10 ... Inspection door 11 ... Gas spring (biasing means)

Claims (2)

A ready-mixed concrete production plant in which a mixing shaft is passed through a mixing tank horizontally and rotatably supported. A mixing blade is attached to the mixing shaft, and a dust-proof cover body is disposed on the upper part of the mixing tank. In the mixer installed in the mixing tank, the side wall parallel to the mixing axis of the mixing tank falls below the rotation trajectory of the tip of the mixing blade from the side wall on the bearing side, and is dropped below a predetermined height so that the mixed material does not come into contact therewith. While the step is formed, the cover body side wall on the side parallel to the mixing axis is extended downward by the amount corresponding to the step to widen the cover body side wall. A large inspection door having a height that is increased by an extension of the width and a width that extends over substantially the entire width of the side wall, and the inspection door pivots up and down with its upper end pivotally supported on the side wall of the cover body. The inspection door can be opened and closed freely. Mixer characterized by comprising biasing means for biasing in the opening direction.   2. The mixer according to claim 1, wherein the biasing means is a gas spring.

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