JPH0115825B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic sand testing device that automatically measures the compactability value, moisture content, air permeability, and strength of granular materials, mainly foundry sand. Conventionally, this type of testing device has been used to manually measure a certain amount of sample in a testing laboratory, so most testing devices cannot be installed in a line to automatically measure the amount. In addition, as a device that can automatically measure, as seen in Japanese Patent Publication No. 49-27310,
After kneading, there is a device that collects a certain amount of sand from a circulating conveyance line via a conveyor and automatically measures it.
However, this method involves collecting a certain amount of sand transferred from the kneading device to the circulation conveyance line and passing it through a conveyor to the testing device for measurement, so if the measurement results of the sand properties do not meet certain conditions, The sand that has already been transferred from the kneading device to the circulation conveyance line is
The sand is directly sent to a molding device and molded, and molds made from this sand are a cause of molding defects. In addition, while the sampled sand was being sent from the kneading device to the sand testing device via the circulating conveyance line and conveyor, there was a problem in that the properties of the sand changed due to evaporation of moisture, etc., causing errors in the measurement results. In addition, this automatic sand testing device has a complicated structure, which makes maintenance and inspection difficult, and it is difficult to use, so it is hardly ever used.

The present invention has been made in view of these problems, and by automatically measuring the sand taken directly from the kneading device, it is possible to determine the compactability value (tamping ability), moisture content, and aeration of foundry sand. The purpose of the present invention is to provide an automatic sand testing device that is capable of automatically and accurately measuring sand properties and strength, and is compact and easy to use.

The configuration of the present invention will be explained below based on examples. 1 is a kneading device, and on the side wall surface of the kneading device 1,
A sand sampling port 2 is drilled, and a guide tube 3 is attached to the sand sampling port 2 with the openings aligned, and a screw feeder 4 for sand sampling is attached to the guide tube 3. 3 and the inner circumferential wall surface of the kneading device 1, and the tip thereof extends to the inside of the kneading device 1. The screw feeder 4
is connected to a 6-axis drive motor attached to a fixed support plate 5 via a rotary joint 7, and a fixed amount of sand can be taken out from the kneading device 1 by a screw feeder 4 by the rotation of the drive motor 6. It's becoming like that. Reference numeral 8 denotes a cylinder shaped like a cross-section, penetrating to the left and right and opening on one side wall surface, and a sand receiving chute 9 is provided on the upper wall surface of the cylinder body 8 in communication with the sand supply port 8a.
Further, a cover member 10 is fixed to the bottom wall surface of the cylinder 8, and a penetrating hole is provided in the bottom wall surface of the cylinder 8 and the cover member 10 at a position on the same line as the sand supply port 8a. A hole 11 is formed in the through hole 11, and a flange portion 1 is provided on the lower surface of the cover member 10.
A sand test tube 12 attached via 2a is fitted. 13 is a horizontal cylinder attached to the fixed plate 14, which passes through the fixed plate 14 loosely and connects the fixed plate 14.
At the tip of the piston rod 13a that protrudes forward,
A cross-sectional scraper member 15 is fixedly connected, and a horizontal plate member 16 is provided on the lower surface of the vertical plate member 15a on the tip side of the scraper member 15 to protrude rearwardly. 16
A flat upper electrode plate 18 is fixed to the lower surface of the sensor via an insulating member 17, and the upper electrode plate 18 is connected to a moisture detector 20 via a conductive wire 19. 21 is an intensity detection device, and the intensity detection device 21
consists of a pressurizing cylinder 22 attached to the lower surface of the upper wall of the scraper member 15, a holding case 23 fixedly connected to the tip of the piston rod 22a, and a holding case 23 held within the holding case 23 for detecting a constant pressure. A pressure detector (load cell) 24 and a detection rod 25 which is held between the lower surface of the pressure detector 24 and the inner surface of the bottom wall of the holding box 23 and whose tip protrudes slidably below the holding box 23. and the pressure detector 24
and a pressurizing converter 27 connected via a conductor 26 to convert the pressure value into a voltage value, and the strength of the compacted foundry sand is detected and converted into an electrical signal for measurement. I'm starting to be able to do it.
Reference numeral 28 denotes a cylindrical member equipped with a lower electrode plate 29 having a ventilation hole (not shown) on its upper end surface, which is connected to the sand test tube 1.
2 is slidably inserted. The sand test tube 1
A flange portion 31a of a cylinder 31 is attached to the lower surface of the flange portion 12a of the cylinder 31 via an O-ring 30, and a piston member 32 having a conical tip is slidably inserted into the cylinder 31 via an O-ring 33. It is inserted. The piston member 32 is integrally formed with a piston rod 35a of a vertical cylinder 35 that is attached upward to a fixed support plate 34, and a horizontal member 36 protruding from the bottom surface of the step of the piston member 32 has a horizontal member 36 at its tip. , horizontal member 3
6, a rack gear 37 is provided perpendicularly to the rack gear 37, a pinion 38 is meshed with the rack gear 37, and the rotational speed of the pinion 38 is transmitted to a rotary electric signal converter 39, which is a compactor for molding sand. The integrity value is detected and converted into an electrical signal so that it can be measured.

Further, the lower electrode plate 29 includes a cylindrical member 28,
Transmission can be made to a horizontal member 36 via the sand test tube 12, cylinder 31, and piston member 32, and the horizontal member 36 is connected to a conductor 40.
connected to the moisture detector 20 via
By applying a voltage between the upper electrode plate 18 and the lower electrode plate 29, the water content of the foundry sand on both electrode plates 18 and 29 can be detected and measured.

In addition, the flange portion 31a of the cylinder 31 has
An air supply hole 41 communicating with the inside of the cylinder 31 is bored, and an air supply source 43 is connected to the air supply hole 41 via a conduit 42, and a flow control valve is provided in the middle of the conduit 42. 44 and a solenoid valve 44a are inserted. And air supply hole 4
1, a pressure detector 45 is provided with its tip facing the air supply hole 41, and the pressure detector 45 is connected to a pressure transducer 47 via a conductor 46. It is possible to detect and measure the air permeability of the molding sand compacted in the chamber 12. A thermocouple 48 extends through the vertical plate member 15a of the scraper member 15 and protrudes into the sand supply path, and is provided to detect and control the sand temperature.

Next, the operation of the device configured as described above will be explained. When the screw feeder 4 rotates through the rotary joint 7 due to the operation of the drive motor 6, the molding sand for sampling in the kneading device 1 is taken out by the screw feeder 4 and sent through the sand receiving chute 9. As the sand is poured into the test tube 12 in a heaping manner, the horizontal cylinder 13 is extended to remove the upper electrode plate 18 together with the scraper member 15 until its center position coincides with the position on the central axis of the sand test tube 12. It moves forward and once stops, and the sand on the top surface of the sand test tube 12 is leveled so that it is flush with the top end surface of the sand test tube 12.

Next, when compressed air controlled at a constant pressure is supplied to the head side of the vertical cylinder 35, the piston member 32 rises due to the extension operation of the vertical cylinder 35, and its conical tip touches the cylindrical member 28 and the lower electrode. The plate 29 is pushed up and the molding sand in the sand test tube 12 is compacted with the upper electrode plate 18 to form a test piece. The upward stroke of the piston member 32 is transmitted to the pinion gear 38 via the rack gear 37, and the rotational speed of the pinion gear 38 is determined by the rotating electrical signal converter 39.
The compactability value (tamping property) of the test piece is detected and measured.

Note that the larger the upward stroke of the piston member 32 and the higher the rotation speed of the pinion gear 38, the higher the compactability value. Conversely, the smaller the upward stroke of the piston member 32 and the lower the rotation speed of the pinion gear 38, the higher the compactability value. Indicates a low Tei value. At the same time, AC 15V is applied between the pair of upper and lower electrode plates 18 and 29.
The electrical resistance of the test piece in the sand test tube 12 is detected by the moisture detector 20 by applying a voltage of 1, and thereby the moisture content is measured.

That is, the larger the electrical resistance, the less water there is, and the smaller the electrical resistance, the more water there is. Then, the horizontal cylinder 13
By the extension operation, the strength detection device 21 is moved forward together with the scraper member 15 until its central axis position coincides with the central axis position of the sand test tube 12, and then stopped. Then, the solenoid valve 44a is opened and the flow rate is increased. Compressed air at a constant pressure, which is controlled at a constant flow rate via a control valve 44, is supplied to the air supply hole 4 from an air supply source 43.
1 into the cylinder 31, the compressed air flows into the sand test tube 12 through a vent (not shown) provided in the lower electrode plate 29, ventilates the test piece, and is discharged upward. When the compressed air passes through the air supply hole 41, the pressure is detected by the pressure detector 45, and the air permeability of the test piece is measured by the pressure transducer 47 as an electric signal. At the same time, when the pressure cylinder 22 is extended, the detection rod 25 descends through the pressure detector 24 and hits the test piece, and the pressure reaction force of the detection rod 25 is applied to the pressure detector 24. 24, and the strength of the test piece is converted into an electrical signal and measured by a pressure transducer 27. Thereafter, the horizontal cylinder 13 and the pressure cylinder 22 are retracted to return the scraper member 15 and the detection rod 25 to their original positions, and then the vertical cylinder 35
The extension action of 1 pushes the test piece above the sand test tube 12, and the extension action of the horizontal cylinder 13 moves the scraper member 15 forward again to push the test piece forward. After extrusion, the horizontal cylinder 13 is retracted to return the scraper member 15 to its original position in preparation for the next operation.

As is clear from the above description, according to the present invention, molding sand is collected directly from the kneading device and continuously detected and measured using a simple automatic sand testing device. The molds are molded using sand under the best conditions, resulting in efficient production of good molds, and the simple structure makes maintenance and inspection easy. The contributing effects are significant.

[Brief explanation of drawings]

Fig. 1 is a front sectional view showing an embodiment of the present invention, Fig. 2 is a front sectional view showing an embodiment of the present invention;
This figure is a side sectional view of FIG. 1, and FIG. 3 is an enlarged sectional view of the intensity detection device section in FIG. 1. 1: Kneading device, 12: Sand test tube, 15: Scraper member, 18: Upper electrode plate, 20: Moisture detector, 21: Strength detection device, 29: Lower electrode plate, 3
2: Piston member, 39: Rotary electric signal converter,
41: Air supply hole, 45: Pressure detector, 47: Pressure transducer.

Claims (1)

[Claims] 1. Sand test tubes arranged at regular intervals below the sand sampling port in the kneading device and used to charge a certain amount of foundry sand for sampling directly taken out from the sand sampling port; a scraper member provided above so as to be movable horizontally with respect to the upper end surface of the sand test tube; attached to the front lower end of the scraper member so that the lower end surface is aligned with the upper end surface of the sand test tube; an upper electrode plate provided in the upper electrode plate; a device for measuring the strength of molding sand that is installed in parallel with the upper electrode plate and is attached to the rear part of the scraper member and compacted; in the sand test tube; a lower electrode plate with air permeability that is slidably inserted; the lower electrode plate is pushed up and pressed between the molding sand in the sand test tube and the upper electrode plate to compact the molding sand; a piston member for;
a device for detecting the upward stroke of the piston member and measuring the compactability value of the compacted foundry sand; A device for supplying sand into the sand test tube, allowing the sand to flow through the compacted molding sand, and exhausting the air through the ventilation hole of the upper electrode plate, thereby detecting and measuring the air permeability of the molding sand; An automatic sand testing device comprising: a device for detecting and measuring moisture in the compacted foundry sand by applying a voltage between the two electrode plates.