JPH0618675Y2 - Kneading equipment for foundry sand - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a kneading device for foundry sand.

(Prior Art) After the molding sand is kneaded by a kneading device after use, an excessive amount of fine powder which is not preferable for ensuring the casting quality is removed and reused repeatedly. The kneading device is provided with a cylindrical main body having a sand inlet for receiving a molding sand to be subjected to a kneading treatment and a sand outlet for taking out the treated molding sand, and the cylindrical main body provided at the bottom of the cylindrical main body. A rotary stirrer for kneading the foundry sand in the main body, a blower for pressure-feeding aeration air to the bottom of the tubular body, and the aeration air in communication with the relatively upper portion of the tubular body. And an exhaust pipe for discharging the powder together with the fine powder. The aeration air containing the molding sand fine powder in the exhaust pipe is usually sucked out by an induction blower and guided to an appropriate dust collector, and after removing most of the molding sand fine powder, it is released into the atmosphere. It

(Problems to be solved by the invention) In the above-mentioned conventional foundry sand kneading apparatus, the blower for pressure-feeding aeration air and the induction blower for sucking out aeration air containing fine molding sand powder in the exhaust pipe are each of a fixed capacity. It is equipped with On the other hand, since the amount of fine powder gradually increases each time the molding sand is repeatedly reused, in the kneading device equipped with the blower having the fixed capacity, the quality of the recovered molding sand, particularly the fine powder content, is accurately controlled. Is difficult.

The present invention improves the drawbacks of the conventional molding sand kneading device,
It is an object of the present invention to provide a kneading device capable of exhibiting the ability to remove fine powder according to the characteristics of foundry sand.

(Means for Solving the Problems) The present invention was devised to achieve the above object, and has a sand inlet for receiving the molding sand to be treated and a sand outlet for removing the treated sand. A tubular body, a rotary agitator arranged at the bottom of the tubular body for kneading the foundry sand in the body, a blower for sending air for aeration to the bottom of the tubular body, and the tubular shape A device comprising an exhaust conduit communicating with a relatively upper portion of the main body for discharging the aeration air to the outside together with the fine powder in the casting sand, wherein the exhaust conduit is provided with a secondary air intake device communicating with the atmosphere, The gist of a kneading device for foundry sand is characterized in that a valve device for controlling an effective opening area to the atmosphere is provided in the secondary air intake device.

(Operation) According to the present invention, the secondary air intake device is provided in the exhaust conduit for discharging the aeration air containing the fine powder in the casting sand to the outside, and the secondary air intake device is installed in the secondary air intake device to the atmosphere. Since a valve device that controls the effective opening area is provided, by operating the valve device according to the nature of the foundry sand to control the secondary air intake amount, the amount of fine powder that is floating and sorted by the aeration air. Can be controlled.

(Embodiment) An embodiment of the present invention will be specifically described below with reference to the accompanying drawings. Reference numeral 10 in the figure denotes a tubular body of the foundry sand kneader,
The cylindrical main body 10 has a sand inlet 14 for receiving the raw molding sand carried by the conveyor device 12, and a sand outlet 18 for taking out the kneaded treated molding sand to the outside and mounting it on the conveyor device 16. It is equipped with Further, at the bottom of the cylindrical main body 10, a rotary stirring device 20 known per se for stirring foundry sand is used.
Is provided, and an air chamber 24 for supplying aeration air is provided below the rotor 22 that forms an umbrella shape of the rotary stirring device. The air chamber 24 communicates with the discharge side of a normal rotary blade type blower or blower 26.

One end of an exhaust conduit 28 is connected to a relatively upper portion of the cylindrical main body 10, and the other end of the exhaust conduit 28 is connected to the suction side of an induction blower or a ventilator 32 via an appropriate dust collector 30. The discharge side of the blower or the ventilator 32 communicates with the atmosphere via a chimney or an exhaust stack as needed. Further, a secondary air intake device 34 having one end communicating with the atmosphere is connected to a portion of the exhaust conduit 28 closest to the cylindrical main body 10, and an appropriate actuator 36 (inside the secondary air intake device 34). In the illustrated embodiment, a valve device 38 whose opening degree is controlled by an air cylinder is shown as an example.

In the above configuration, the conveyor device 12 to the tubular body 10
The raw material molding sand to be kneaded is stirred by the rotary stirrer 20 and comes into contact with aeration air that has been pressure-fed into the tubular body through the air chamber 24 by the blower or the ventilator 26. Most of the fine particles smaller than the set particle size, for example, 200 mesh, contained in the foundry sand float in the air for aeration and enter the exhaust conduit 28, and are attracted by the induction blower or the air blower 32 to be collected by the dust collector 30. Mostly separated. Most of the fine powder separated by the dust collector 30 is cleaned and the purified air is discharged from the chimney and the exhaust stack to the atmosphere. The foundry sand kneaded in the tubular body 10 is mounted on the conveyor device 16 from the sand removal port 18 and sent to the next step.

The treated molding sand taken out to the conveyor device 16 is sampled to check the fine powder content, and if the fine powder content is set to a predetermined upper limit value (of course, a fine powder content slightly lower than the allowable upper limit value is set. (Preferably a value), the valve device 38 is operated in the closing direction by the actuator 36 to reduce the effective opening area of the secondary air intake device 34, and the secondary air flowing into the exhaust conduit 28 is discharged. By reducing the amount of air, the aeration effect in the cylindrical main body 10 is enhanced. On the contrary, when the fine powder content is sufficiently lower than the above upper limit set value, the valve device is operated in the opening direction by the actuator 36 and the secondary The effective opening area of the air intake device 34 is increased to reduce the aeration effect in the cylindrical main body 10 and suppress the discharge amount of fine powder. In this way, by controlling the amount of secondary air flowing into the exhaust conduit 28 by the valve device 38 and controlling the effect of aeration performed in the tubular body 10, the fine powder content of the foundry sand after the kneading treatment is desired. Since it can be adjusted within the control width of, there is an advantage that molding and casting in the subsequent process can be smoothly performed.

In the illustrated embodiment, the valve device 38 of the secondary air intake device 34 is shown as a butterfly valve, but a slide valve or any other valve device can be appropriately adopted.

(Effect of the Invention) As described above, the kneading device for foundry sand according to the present invention has a cylindrical shape having a sand inlet for receiving the foundry sand to be treated and a sand takeout port for taking out the treated foundry sand. A main body, a rotary agitator arranged at the bottom of the tubular body to knead the foundry sand in the main body, a blower for sending air for aeration to the bottom of the tubular body, and relatively above the tubular body. In the one comprising an exhaust conduit communicating with the portion and discharging the aeration air to the outside together with the fine powder in the foundry sand, the exhaust conduit is provided with a secondary air intake device communicating with the atmosphere,
The secondary air intake device is provided with a valve device for controlling the effective opening area to the atmosphere, and by providing a simple variable-volume secondary air intake device in the conventional kneading device, Since the fine powder content of the foundry sand can be appropriately controlled, it is extremely useful in practice.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. 10 ... tubular body of kneader, 12 and 16 ... conveyor device, 14 ... sand inlet, 18 ... sand outlet, 20 ...
Rotating stirrer, 26 and 32 ... Blower or ventilator, 2
8 ... Exhaust pipe, 34 ... Secondary air intake device, 36 ...
Actuator, 38 ... Valve device.

Claims (1)

[Scope of utility model registration request] 1. A tubular body having a sand inlet for receiving the molding sand to be treated and a sand outlet for taking out the treated molding sand, which is arranged at the bottom of the tubular body and A rotary stirrer for kneading the foundry sand, a blower for sending air for aeration to the bottom of the tubular body, and a relatively high portion of the tubular body communicating with the aeration air together with the fine powder in the foundry sand. In the device comprising an exhaust pipe for exhausting to the above, a secondary air intake device communicating with the atmosphere is provided in the exhaust pipe, and a valve device for controlling an effective opening area to the atmosphere is provided in the secondary air intake device. A kneading device for foundry sand characterized by being provided.