Integrated sand mixer and sand mixing method
Technical Field
The invention relates to a machine used in the metal casting industry, in particular to an integrated sand mixer and a sand mixing method, and particularly relates to a sand mixer and a sand mixing method which are suitable for an inorganic process and a cold core process.
Background
In the metal casting industry, the preparation of sand cores is an important component of the casting process. In the process, sand needs to be uniformly mixed with a binder, a curing agent or other additives to prepare molding sand (or core sand), and in the prior art, the mixing is usually realized by adopting a stirring manner.
The conventional sand mixer usually comprises a sand quantifying unit, a powdery auxiliary material quantifying unit, a liquid material quantifying unit and a sand mixing unit, wherein the sand quantifying unit quantifies raw sand through a volume quantifying mode or an electronic quantifying mode, the powdery auxiliary material quantifying unit quantifies powdery additives electronically, the liquid material quantifying unit quantifies liquid resin mainly, and the sand mixing unit quantifies the raw sand, the auxiliary materials, the liquid materials and other materials in the quantitative proportion to be finally mixed so as to obtain a mixture with excellent uniformity required by core making. For example, chinese utility model patent CN208050869U discloses a sand mixer, including mixing a sand section of thick bamboo, set up at the feed inlet of mixing a sand section of thick bamboo top, a support frame for supporting mixing a sand section of thick bamboo, rotate the (mixing) shaft of connecting in mixing a sand section of thick bamboo bottom and stretching into mixing a sand section of thick bamboo inner chamber and set up the motor that is used for providing power to the (mixing) shaft bottom mixing a sand section of thick bamboo, still include fixed connection at the epaxial stirring leaf of stirring, set up the stirring board on stirring leaf working face, set up at the discharge door of mixing a sand section of thick bamboo side and be used for controlling the actuating mechanism that the discharge door was opened and was closed, the stirring board can be dismantled the connection and be in on the stirring leaf, (mixing) shaft and the coaxial setting of mixing a sand section of thick bamboo.
The sand mixing can be realized by the above technology, and through arranging the detachable stirring plate, the sand adhered to the working surface can be conveniently cleaned. However, with the popularization of the inorganic process and the cold core process, the use of the sand mixer is limited, and the sand mixer is mainly embodied in the following aspects:
(1) the beat time of the process is too long.
For example, in inorganic processes, raw sand needs to be mixed with one or more powders and one or more liquids, and the raw sand must be initially mixed with the powders to a certain homogeneity before being mixed with the liquids. Therefore, the conventional process requires dry mixing for about 60 seconds by a sand mixer, addition of an inorganic resin, wet mixing for about 60 seconds, and other transition steps, and requires about 144 seconds for operation time.
In the cold core process, the operation time required by the above method is also about 93 seconds.
However, in order to cooperate with an efficient core making machine, it is required that the above-mentioned action time be controlled within 60s, and it is clear that the process tact of the prior art does not satisfy this requirement.
(2) The stirring blades of the sand mixer are horizontally arranged, so that in order to achieve an excellent mixing effect, the required mixing time (for example, 60 s) is long, which causes high temperature rise on one hand and is not suitable for an inorganic process or a cold core process on the other hand, and also causes that the takt time of the whole process is difficult to shorten on the other hand.
(3) Because of adopting the horizontal blade structure, a larger gap exists between the bottom of the blade and the stirring barrel, and the sand of the part can not be effectively mixed, thereby reducing the mixing quality of the core sand mixture and simultaneously making the cleaning more difficult.
(4) The sand mixing barrel of the sand mixer cannot be conveniently and quickly disassembled, the liner of the barrel wall of the daily maintenance machine and the cleaning machine need to be replaced or cleaned on line, the machine needs to be shut down, and the normal production is influenced.
Therefore, there is a need for an improved sand mixer and sand mixing method to overcome the above-mentioned disadvantages.
Disclosure of Invention
The invention aims to provide a sand mixing method, which shortens the takt time of a sand mixing process, realizes efficient matching with a core making machine, avoids excessive temperature rise of molding sand and is suitable for a cold core process and an inorganic process through process improvement. Another object of the present invention is to provide an integrated sand mixer for implementing the sand mixing method.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows: a sand mixing method is realized by adopting a blade stirring type sand mixer, the sand mixer is provided with a sand quantifying device and a stirring cylinder, and the sand mixing method comprises the following steps:
(1) arranging a premixing blade in a sand quantifying device, and arranging a premixing power mechanism for driving the premixing blade to enable the sand quantifying device to form a premixing barrel;
(2) a powder material feeding hole and a liquid material feeding hole are respectively arranged on the mixing drum, and an outlet of the premixing drum is connected to the powder material feeding hole of the mixing drum through a valve, so that the mixing drum forms a final mixing drum;
(3) carrying out quantitative addition of raw sand, quantitative addition of powdery auxiliary materials and premixing operation of the raw sand and the powdery auxiliary materials in the premixing cylinder;
(4) quantitatively feeding the raw sand premixed with the powdery auxiliary materials and the liquid resin material into a final mixing cylinder, driving the stirring blades to rotate, and uniformly mixing to obtain the required molding sand;
and when the final mixing barrel is used for stirring, the next circulation of quantitative addition of the raw sand, quantitative addition of the powdery auxiliary material and premixing operation of the raw sand and the powdery auxiliary material are synchronously performed in the premixing barrel.
In the technical scheme, the premixing blades are arranged in the sand quantifying device and are changed into the premixing barrel, so that two-stage sand mixing is realized on the premise of not increasing a container.
According to the further technical scheme, the lower part of the final mixing barrel is set to be a conical structure with a large upper part and a small lower part, and the stirring blade in the final mixing barrel is set to be an inclined blade arranged in parallel with the conical barrel wall.
The lower part of the final mixing barrel is arranged to be of a conical structure, and a tilting blade structure is matched, so that a core sand mixture with high quality and excellent uniformity can be obtained in a short time, and excessive temperature rise of the core sand is avoided.
According to the preferable technical scheme, the rotating speed of the stirring blades is 150-250 revolutions per minute.
According to the further technical scheme, a vibration device is arranged at an outlet at the lower part of the premixing barrel, and the vibration device is started to clean residual sand of the premixing barrel after the final mixing barrel is fed.
In the technical scheme, in each process takt time, the rotating and stirring time of the stirring blades in the final mixing cylinder is not more than 45 s.
In order to realize another purpose of the invention, the invention provides an integrated sand mixer, which comprises a frame, a final mixing barrel arranged on the frame, a stirring blade arranged in the final mixing barrel, and a final mixing power mechanism for driving the stirring blade, wherein the top of the final mixing barrel is provided with a feeding hole, the bottom of the final mixing barrel is provided with a discharging hole, the final mixing power mechanism is provided with a premixing barrel, the premixing barrel is internally provided with a premixing blade, the premixing blade is driven by the premixing power mechanism, an outlet at the bottom end of the premixing barrel is connected to the feeding hole at the top of the stirring barrel through a sand sliding pipe, and the sand sliding pipe is provided with a valve; the lower part of the final mixing barrel is of a conical structure with a large upper part and a small lower part, and the stirring blade is provided with an inclined blade which is arranged in parallel to the wall of the conical barrel.
In the above technical scheme, the premixing barrel is a conical hopper, and a weighing sensor is arranged on the frame in cooperation with the conical hopper.
According to a further technical scheme, a vibration device is arranged at an outlet at the lower part of the premixing barrel.
In the technical scheme, a fixed auxiliary blade is arranged in the final mixing cylinder; and a sand outlet knife gate valve is arranged at an outlet at the bottom of the mixing drum. The fixed auxiliary blade of configuration in the final mixing barrel can play the vortex effect, aggravates the effect of churning of a section of thick bamboo inner core sand, guarantees to obtain more even mixture in shorter time. The auxiliary blade may be provided at an upper portion of the final mixing barrel.
Among the above-mentioned technical scheme, mix a section of thick bamboo eventually and be provided with quick detachable formula structure, can realize the quick detach and the clearance maintenance under the line of barrel. The premixing barrel and the final mixing barrel are respectively provided with a maintenance door which can be used for internal blade replacement and daily cleaning and maintenance.
Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:
1. according to the invention, the premixing blades are arranged in the sand quantifying device and are changed into the premixing barrel, so that two-stage sand mixing is realized on the premise of not increasing a container, one stage is a premixing unit, the quantification of the raw sand and the dry mixing process of the raw sand and the powder additive can be realized, the other stage is a final mixing unit, the wet mixing process of the mixture of the primary premixing unit and the liquid material can be realized, the two units can work simultaneously, and the sand mixing time is greatly shortened through automatic program control and matching.
2. The premixing unit is provided with the premixing blades, so that the raw sand and the powder can be primarily mixed, a relatively uniform initial mixture can be obtained, and the premixing unit sand mixing motor is provided with a frequency conversion function, so that the relation among mixing time, sand mixing temperature rise and uniformity can be adjusted at will.
3. The final mixing unit is provided with a high-speed sand mixing motor, the final mixing barrel adopts a conical barrel body and an inclined blade structure, core sand mixture with high quality and excellent uniformity can be obtained in a short time, the final mixing unit sand mixing motor is provided with a frequency conversion function, and the relation among mixing time, sand mixing temperature rise and uniformity can be adjusted at will.
4. The sand dead weight whereabouts in a section of thick bamboo can be realized to toper tube structure and setting in the sand outlet of bottom, and a section of thick bamboo is interior sand and is remained still less, only needs clearance section of thick bamboo wall during the clearance, and sand can flow from the sand outlet automatically, and the clearance time is shorter, and the degree of difficulty is also littleer.
5. The final mixing barrel of the sand mixer can be quickly disassembled, and meanwhile, a barrel body lifting mechanism is arranged, so that the final mixing barrel can be manually replaced, and offline cleaning and maintenance are realized.
Drawings
FIG. 1 is a schematic structural diagram of an embodiment of the present invention;
FIG. 2 is a left side view of FIG. 1;
fig. 3 is a sectional view a-a of fig. 2.
Wherein: 1. a frame; 2. a final mixing cylinder; 3. a premix barrel; 4. a sand sliding pipe; 5. a knife gate valve; 6. stirring blades; 7. premixing blades; 8. a premixing power mechanism; 9. a final mixing power mechanism; 10. a weighing sensor; 11. a sand knife gate valve is arranged; 12. a sand hopper; 13. a powder dosing device; 14. a final mixing barrel maintenance door; 15. a premix barrel maintenance door; 16. auxiliary blades.
Detailed Description
The invention is further described with reference to the following figures and examples:
the first embodiment is as follows: referring to fig. 1 to 3, an integrated sand mixer comprises a frame 1, a final mixing barrel 2 arranged on the frame, and a pre-mixing barrel 3 arranged above the side of the final mixing barrel 2, wherein an outlet at the bottom end of the pre-mixing barrel 3 is connected to a top feed inlet of the final mixing barrel 2 through a sand chute 4, and a knife gate valve 5 is arranged on the sand chute 4.
The premixing barrel 3 is a conical hopper, the upper part of the premixing barrel is connected with a sand hopper 12 and a powder quantifying device 13, a premixing blade 7 is arranged in the conical hopper, the premixing blade 7 is driven by a premixing power mechanism 8, the premixing power mechanism 8 can be composed of a motor and a corresponding speed reducing mechanism, and a weighing sensor 10 is arranged on a rack in cooperation with the premixing barrel 7. Mix a 2 lower parts of section of thick bamboo for big-end-up's toper structure, be equipped with stirring leaf 6 in the section of thick bamboo, stirring leaf 6 has the slope blade that is on a parallel with the arrangement of toper section of thick bamboo wall, and stirring leaf 6 is driven by final mixing power unit 9, and final mixing power unit 9 can constitute by motor and corresponding reduction gears, can drive the stirring leaf through quick connecting device removable to in order to mix a quick dismantlement and the clearance under the line of a section of thick bamboo eventually, 2 bottom exits of a section of thick bamboo of churn are equipped with sand knife gate valve 11.
A premixing barrel maintenance door 15 and a final mixing barrel maintenance door 14 are respectively arranged on the premixing barrel and the final mixing barrel, and can be used for internal blade replacement and daily cleaning and maintenance.
In this embodiment, a vibration device may be provided at the lower outlet of the premix barrel.
The final mixing barrel is also provided with fixed auxiliary blades 16 to play a role of turbulence, so that the churning effect of core sand in the barrel is intensified, and a more uniform mixture is obtained in a shorter time.
By adopting the sand mixer of the embodiment, the synchronous operation of premixing and final mixing can be realized, and the final mixing time can be greatly shortened compared with the prior art, so that the matching with a high-efficiency core making machine is realized.
For example, for the cold core process, one possible mulling procedure is:
(1) adding two liquid resin materials (about 8 s) while adding the mixture of the raw sand and the powdery auxiliary materials into the mixing drum by the premixing drum;
(2) the mixing drum is used for mixing sand and stirring (about 25 s);
meanwhile, the premixing cylinder carries out quantitative addition of raw sand, quantitative addition of powdery auxiliary materials and premixing in the next round;
(3) opening a sand discharge knife gate valve to discharge sand (5 s);
(4) the sand knife gate valve is closed (2 s).
Therefore, the whole takt time is 40s, the working efficiency of 90 batches per hour can be achieved, and the takt time is greatly faster than the takt time of 93s in the prior art.
For inorganic processes, one possible mulling procedure is:
(1) adding a liquid resin material (about 12 s) into the mixing drum while adding the mixture of the raw sand and the powdery auxiliary materials into the mixing drum by the premixing drum, wherein a vibration device is started at the last 3 seconds to clean residual sand in the premixing hopper;
(2) the mixing drum is used for mixing sand and stirring (about 40 s);
meanwhile, the premixing cylinder carries out quantitative addition of raw sand, quantitative addition of powdery auxiliary materials and premixing in the next round;
(3) opening a sand discharge knife gate valve to discharge sand (6 s);
(4) the sand knife gate valve is closed (2 s).
Therefore, the whole takt time is 60s, the working efficiency of 60 batches per hour can be achieved, and the takt time is greatly faster than 144s in the prior art.