JPS6363297B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for controlling the amount of water added to foundry sand.

Generally, to control the moisture content of foundry sand that is optimal for moldability, a kneading operator takes out a certain amount of sand from the kneading machine and measures the properties of the sand using a moisture meter or contactor filtration meter. The amount of water added is determined based on this. Also,
Recently, electric resistance moisture meters or microwave moisture meters have begun to be used for automation.
The amount of water added is automatically determined.

However, in the former case, due to manual labor,
There were problems such as the operator's intuition was involved, errors occurred in the measured values, and automation was difficult. Furthermore, since the latter method is an indirect measurement, there are problems such as inaccuracy.

The present invention has been developed in view of these problems, and is capable of accurately and automatically measuring the moisture content of foundry sand, thereby stabilizing the properties of foundry sand and contributing to the production of good molds. It is an object of the present invention to provide a method and apparatus for controlling the amount of water added to foundry sand.

The configuration of the present invention will be explained below based on examples. Reference numeral 1 denotes a sand kneading device, which has a rotary shaft 3 projecting from the center inside a drum 2, and rotary rollers 4 rotatably supported on both sides of the upper portion of the rotary shaft 3. A looper hopper 5 is fixedly arranged above the kneading device 1, and the louver hopper 5 connects flanges 6 protruding from both sides of the outer wall through a first load converter 7 that can electrically convert the load. It is supported on the upper surface of the fixed frame 8. In addition, a louver gate 9 is provided at the outlet of the louver hopper 5.
The louver gate 9 has a boss portion 10 at the proximal end rotatably supported by a fixed shaft 11 fixed to the outer wall of the louver hopper 5, and supported via a support member 12 attached to the outer wall of the louver hopper 5. The rear cover of the louver gate 9 is fixedly connected to the tip of a piston rod 13a of a gate cylinder 13 which is rotatably suspended and supported, and the louver gate 9 is opened and closed by the operation of the gate cylinder 13. 14 is a sand measuring device provided directly above the louver hopper 5, and the sand measuring device 14 has a flange portion 15 protruding from both sides of the outer wall attached to the fixed frame 1.
6, a sand measuring hopper 18 supported on the upper surface via a second load converter 17, and a boss portion 19 at the proximal end that is openable and closably provided at the discharge port of the sand measuring hopper 18;
Fixed shaft 2 attached to the outer wall of the sand measuring hopper 18
The piston rod 2 of the gate cylinder 23 is rotatably supported by the fixed frame 21 via the support member 22, and the rear cover is rotatably supported by the fixed frame 21 via the support member 22.
3a, and a gate plate 24 rotatably connected to the gate 3a, and the gate plate 24 is opened and closed by the operation of the gate cylinder 23.

And the first and second load converters 7, 17
are electrically connected via a microcomputer device (not shown), and the weight of sand stored in a saturated state in the sand weighing hopper 18 is electrically converted by the second load converter 17 and sent to the microcomputer device (not shown). is calculated to calculate the bulk density of sand, and furthermore,
This sand bulk density is calculated into a sand moisture value based on the relationship between the sand bulk density and sand moisture value shown in FIG. Then, by repeating this operation four to five times, the average value can be processed by the microcomputer device.

On the other hand, the weight of sand thrown into the louver hopper 5 is measured by the first load converter 7, and
This measured value is sent to the microcomputer device, and the amount of water added to the foundry sand in the louver hopper 5 is calculated and determined based on the averaged sand moisture value.

The weight of the sand stored in the sand measuring hopper 18 in a saturated state is due to the gradual accumulation of the foundry sand cut out from the sand cutting conveyor 25, and the output voltage of the load converter 17 as shown in FIG. This is the point at which the saturation point within a certain range (between t ₁ and t ₈ hours) is determined. In addition, the sand cutting conveyor 25
is started and stopped by a detection signal from the first load converter 7. 26 is a sand cutting hopper provided above the sand cutting conveyor 25.

With this configuration, when the louver gate 9 and the gate plate 24 are closed,
When the cutting conveyor 25 is started, the foundry sand S cut from the cutting conveyor 25 is gradually accumulated in the sand measuring hopper 18, and as shown in FIG. 5, after a certain period of time, the weight of the accumulated sand, i.e. , the output voltage of the second load transducer 17 reaches a saturation point within a certain range. Then, this output voltage is sent to a microcomputer device electrically connected to the first load converter 7 for the louver hopper 5, and is calculated to calculate the bulk density of the sand, and also calculates the bulk density of the sand and the sand bulk density shown in FIG. Based on the moisture correlation, the sand moisture value is calculated. Then, the gate cylinder 23 is retracted, the gate plate 24 is opened, and the molding sand in the sand measuring hopper 18 is thrown into the louver hopper 5. Thereafter, the gate plate 24 is closed, and the sand measuring hopper 18 again reaches a saturation state with the foundry sand cut out from the sand cutting conveyor 25, and the output voltage of the load converter 7 is sent to the microcomputer device in the same manner as described above. The bulk density of the sand is calculated, and from FIG. 4, the sand moisture value is calculated. In this way, perform the sand measuring operation from 4 to 4.
This process is repeated five times, and the sand weight value is sent to a microcomputer device, where it is calculated into the sand bulk density and sand moisture value, and the average value is processed. On the other hand, when a predetermined amount of foundry sand is stored in the louver hopper 5, the sand cutting conveyor 25 is stopped, and the weight of the sand in the louver hopper 5 is measured by the first load converter 7, and the weight of the sand in the louver hopper 5 is measured by the first load converter 7. Based on the sand moisture value, the amount of water to be added into the kneading device 1 is calculated and determined by a microcomputer device. Next, the gate cylinder 13 is retracted, and the louver gate 9
is opened, the foundry sand in the louver hopper 5 is supplied to the kneading device 1, a predetermined amount of moisture is added, and a kneading operation is performed. Thereafter, the above operation is repeated.

As is clear from the above explanation, according to the present invention, it is possible to accurately and automatically determine the amount of water added to the foundry sand to be kneaded, and as a result, the properties of the sand are stabilized and a good mold is produced. It has the effect of enabling efficient molding, and its contribution to this type of industry is significant.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, FIG. 2 is a view taken along arrow A-A in FIG. 1, and FIG.
The figure is a view taken along the line B--B in FIG. 1, FIG. 4 is a diagram showing the relationship between sand moisture and sand bulk density, and FIG. 5 is a diagram showing the relationship between sand weight and time. 1: sand kneading device, 5: louver hopper, 7: first load converter, 17: second load converter, 9:
Louver gate, 14: sand measuring device, 18: sand measuring hopper, 24: gate plate.

Claims (1)

[Scope of Claims] 1. The measured value of the weight of sand stored in a louver hopper fed into a sand kneading device is electrically converted and inputted to a microcomputer device, while the measured value of the weight of sand of a certain volume is , input to the microcomputer device and calculate the bulk density of sand, and based on the relationship between the bulk density of sand and the sand moisture value stored in advance in the microcomputer device,
Calculate the bulk density into a sand moisture value, and consider the amount of moisture to be added to the foundry sand in the sand kneading device by comparing the required amount of moisture for the foundry sand in the sand kneading device and the measured moisture value. 1. A method for controlling the amount of water added to foundry sand, the method comprising: determining the amount of water added to foundry sand; 2. A louver hopper equipped with a louver gate that can be opened and closed at the casting sand discharge port is installed directly above the sand kneading device.
A second sand measuring hopper is supported by a first load converter capable of electrically converting the measured weight, and directly above the louver hopper is a sand measuring hopper equipped with a gate plate that can be opened and closed at the casting sand discharge port. 1. A control device for controlling the amount of water added to foundry sand, characterized in that the first and second load converters are electrically connected via a microcomputer device.