JP3415497B2 - Method and system for detecting abnormalities in casting sand injection and filling in blow molding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a system for detecting an abnormality in the blow-in filling of molding sand in a blow-in mold molding machine in which molding sand is blown and filled with compressed air.

[0002]

2. Description of the Related Art Conventionally, as blow-in mold molding machines as described above, Japanese Patent Application Laid-Open Nos. 9-164451 and 1
It is publicly known in, for example, 0-216902. In such a blown mold making machine, the molding sand is blown and filled into the molding frame through the sand magazine, the bending cylinder and the blow head.

[0003]

However, in the blow-in molding machine as described above, the flow velocity changes and stalls or flows until the casting sand is blow-filled from the sand magazine into the flask. There is a problem that a part of the molding sand gets worse and is stagnated at the bending portion or the horizontal portion of the bending cylinder and the blow head, and it becomes impossible to properly blow and fill the molding sand into the flask. JP-A-10-21690
As disclosed in Japanese Patent Laid-Open No. 2 (1994), it has been proposed that the blower head is provided with a compressed air jetting mechanism with a vent plug for changing the advancing direction of the molding sand and promoting fluidization of the molding sand. .

As described above, in a blow-in type mold making machine having a blow head with a compressed air jetting mechanism with a vent plug, clogging of foundry sand is generated in the vent plug while the mold making is continued for a long time, and compressed air is generated. There was a problem that the jetting mechanism did not function sufficiently and the molding sand could not be stably blown and filled with the molding sand. The present invention has been made in view of the above problems, the blow-in mold molding machine can properly detect the abnormality of the casting sand blow filling to cope with the next casting sand blow An object of the present invention is to provide a method and a system for detecting abnormalities in filling a casting sand with a casting mold making machine.

[0005]

[Investigation Test] As a result of trying various tests to investigate the above problems, the present inventors found out the following. That is, when the casting sand is normally blown and filled, the pressure of the compressed air in the upper and lower blow heads is obtained from the empirical value as shown in FIG. −
It becomes higher than the preset reference pressure curve due to the pressure in the head and the filling time of the molding sand, while the filling plug of the molding sand is insufficient due to the molding sand clogging at the vent plug of the compressed air ejection mechanism of the blow head. It has been found that the pressure of the compressed air in the blower head becomes lower than the reference pressure curve as shown in FIG.

[0006]

In order to achieve the above object, the first method for detecting abnormalities in the injection of molding sand in a blow-in mold molding machine of the present invention is to blow molding sand together with compressed air into a molding flask. A method for detecting an abnormality of casting sand blow-filling in a blow-in mold making machine for filling and filling, wherein a reference pressure curve is preset from the pressure in the pressure tank, the pressure in the blow head and the filling time of the casting sand. And the step of measuring the actual pressure in the pressure tank, the pressure in the blow head and the filling time of the molding sand, the pressure actually measured in the pressure tank, the pressure in the blow head and the molding sand It is characterized in that the measured pressure curve is calculated from the filling time and the abnormality is detected from the deviation value between the reference pressure curve and the measured pressure curve.

A second method for detecting a casting sand blow-in filling abnormality in a blow-in mold molding machine of the present invention is an upper and lower blower head capable of blowing the molding sand into the upper and lower flasks, and the upper and lower blowers. A sand magazine in which the molding sand can be blown into the head by supplying compressed air from a pressure tank, and a vent provided in the upper and lower blow heads for changing the forward direction of the molding sand and promoting fluidization of the molding sand. A method for detecting abnormalities in the injection of casting sand in a blow-in molding machine equipped with a compressed air jetting mechanism with a plug, the pressure in the pressure tank, the pressure in the upper and lower blow heads, and the filling time of the casting sand. From the step of presetting the reference pressure curve from the actual pressure tank, the step of measuring the pressure in the upper and lower blow heads and the filling time of the molding sand, the pressure in the pressure tank actually measured, It is characterized in that to detect an abnormality from the divergence value of the measured pressure curve and the reference pressure curve to calculate the measured pressure curve from the filling time of the pressure and molding sand in the head - down blow.

Furthermore, the casting sand blow-in filling abnormality detection system in the blow-in mold making machine of the present invention is provided with an upper and lower blower head capable of blowing the molding sand into the upper and lower flasks, and castings in the upper and lower blower heads. Sand magazine which can be blown and supplied with compressed air from a pressure tank, and a vent plug provided on the upper and lower blow heads for changing the forward direction of the casting sand and promoting fluidization of the casting sand A compressed sand jetting mechanism, and a casting sand blow filling abnormality detection system in a blown mold molding machine comprising: a compressed air pressure tank pressure obtained from experience values; a pressure in the upper and lower blow heads; and Storage means for pre-storing a reference pressure curve set by the molding sand filling time, a pressure detector in the pressure tank, a pressure detector in the upper and lower blow heads, and detection of the molding sand filling time. And input means for inputting the output from each of these detectors, the reference pressure curve stored in the storage means, the pressure in the pressure tank input to the input means, the pressure in the upper and lower blow heads, and the molding sand. Comparing means for comparing the measured pressure curve from the filling time of, and a judging means for judging whether the deviation value between the reference pressure curve and the measured pressure curve is not less than an allowable value. Is.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The upper and lower flask simultaneous blowing type mold making machines used in the present invention will be described below with reference to FIG. This mold molding machine blows a match plate 1, upper and lower flasks 2 and 3 which can be brought into contact with the upper and lower surfaces of the match plate 1, and blows molding sand onto the upper and lower flasks 2 and 3. It comprises upper and lower elbow-shaped blower heads 4 and 5 that can be inserted, and a sand magazine 6 that can blow and supply molding sand to the upper and lower blower heads 4 and 5.

The upper and lower flasks 2 and 3 are moved up and down by a cylinder (not shown).
The heads 4 and 5 are attached to the tip ends of piston rods 7 and 8 of a cylinder installed in a frame (not shown) so as to be moved up and down. The upper and lower blow heads 4 and 5 are provided with vent plugs 9 and 9 for ejecting compressed air for promoting the change of the advancing direction of the molding sand in the upper and lower blow heads and the fluidization of the molding sand. Air ejection mechanism 1
0 and 10 are provided respectively. The compressed air ejection mechanisms 10 and 10 are in communication with the pressure tank 16 via a pressure control valve (not shown).

Further, the sand magazine 6 is composed of upper and lower sand tanks 11 and 12, and the upper sand tank 11 is connected to the pressure tank 16 via a pressure control valve 17 from an upper bending cylinder 13 to the upper blow tank. The lower sand tank 12 can be communicated with the head 4, and the lower sand tank 12 can be communicated with the lower blower head 5 from a lower bent cylinder 14 that communicates with the pressure tank 16 via a pressure control valve 17. A compressed air supply port 15 communicating with the pressure tank 16 via a pressure control valve 17 is provided at an upper position of the sand magazine 6. Further, the upper and lower blow heads 4 and 5 and the pressure tank 16 are respectively provided with pressure sensors-4A, 5A and 16A for continuously measuring the internal air pressure and outputting the result to a microcomputer (not shown). Has been done. The micro computer is electrically connected so as to control a pressure control valve (not shown) communicating with the compressed air ejection mechanisms 10 and 10 of the upper and lower blow heads 4 and 5.

Next, the blow-filling of the foundry sand by the thus constructed one will be described. Top and bottom sand tank 1 in the state of Figure 1
A predetermined amount of molding sand is put into Nos. 1 and 12, and then compressed air is supplied from the pressure tank 16 to the sand magazine 6 and the compressed air jetting mechanisms 10 and 10 of the upper and lower blow heads 4 and 5.
Compressed air controlled by a pressure control valve (not shown) is supplied to blow and fill the molding sand into the upper and lower flasks 2 and 3 (described below with reference to FIG. 2). At this time, the internal pressure of each of the upper and lower blow heads 4 and 5 and the pressure sensors 4A, 5A and 16A of the pressure tank 16 are measured and output to a microcomputer (not shown).

Next, the pressure of the compressed air in the upper and lower blow heads 4 and 5 is compared with a reference pressure curve (which will be described in detail below) obtained from an empirical value and stored in advance. As a result, as shown in FIG.
If the pressure of the compressed air inside is higher than the reference pressure curve,
Continue the next molding sand blow filling. Here, the reference pressure curve is a value that the filling time of the molding sand is 1.2 seconds,
The curve is based on a value 0.05 MPa lower than the minimum value of the pressure of the compressed air in the pressure tank 16. Further, the pressure of the compressed air in the passage of the molding sand is unstable during the filling of the molding sand, and it may temporarily take a value lower than the reference pressure curve. A value of 03 MPa is given. However, the reference pressure curve stored in advance in the comparison calculation step has a slight difference depending on the configuration of the mold making machine or the size of the mold to be molded.

On the other hand, when the comparison calculation result shows that the pressure of the compressed air in the upper and lower blow heads 4 and 5 is outside the allowable range lower than the reference pressure curve as shown in FIG.
Alternatively, it is judged that there is an abnormality such as clogging of the sand in the vent plugs 9 and 9 of 5 or blown air, and the abnormality is detected. In this way, when an abnormality such as clogging of the casting sand in the vent plugs 9, 9 or blowout of air is detected, the operation of the molding machine is temporarily stopped to automatically or manually release the clogging of the casting sand or eliminate the blowout of air. After performing the maintenance as described above, move on to the next work for filling the sand with blown sand.

In the above embodiment, the match plate 1 is applied to the upper and lower molds simultaneous blowing type mold making machine in which the molding sands are simultaneously blown and filled into the upper and lower molds 2 and 3. Is similarly applied to a mold making machine in which the molding sand is filled by blowing molding sand into one molding frame.

[0016]

As is apparent from the above description, the present invention relates to the behavior of the pressure of compressed air in the blow head,
Since it detects abnormalities such as clogging of the molding sand of the vent plug and blow-through of air from the reference pressure curve that is obtained from experience values and is stored in advance, the abnormality should be detected before it adversely affects the original filling of the molding sand. It has an excellent effect of being able to detect and maintain the abnormality.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view of a main part of an upper and lower flask simultaneous blowing type mold making machine which is an object of the present invention.

FIG. 2 is a flowchart showing the present invention.

FIG. 3 is a graph showing a time period in which a molding tank is blown into a pressure tank, a sand magazine, and upper and lower blow heads, and an air pressure state in a normal state.

FIG. 4 is a graph showing the time of casting sand blowing and the air pressure state of the pressure tank, the sand magazine, and the upper and lower blow heads during sand clogging.

[Explanation of symbols]

2 Upper flask 3 Lower flask 4 Upper blow head 5 Lower blow head 6 Sand Magazine 9 Vent plug 10 Compressed air ejection mechanism 16 Pressure tank 4A 5A 16A Pressure sensor-

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taiki Makino, 3-chome, Honohara, Toyokawa City, Aichi Prefecture, Shinto Kogyo Co., Ltd. Toyokawa Plant (56) Reference JP-A-10-216902 (JP, A) 58-107251 (JP, A) JP-A-6-277800 (JP, A) Fukui 4-54546 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B22C 11 / 00-25/00

Claims (5)

(57) [Claims] 1. A method for detecting an abnormality in the blow-in of a molding sand in a blow-in mold molding machine in which the molding sand is blown and filled with compressed air. Step of presetting the reference pressure curve from the pressure of and the filling time of the molding sand, the pressure in the actual pressure tank,
Measuring the pressure in the blow head and the filling time of the molding sand, and calculating the actual pressure curve from the pressure in the pressure tank actually measured, the pressure in the blow head and the filling time of the molding sand, and An abnormality detection method for foundry sand blow filling in a blow-in mold molding machine, which detects an abnormality from a deviation value between a reference pressure curve and an actually measured pressure curve. 2. The reference pressure curve is set by the pressure in the pressure tank, the pressure in the blow head, and the filling time of the molding sand obtained from empirical values. Method for Abnormal Filling of Foundry Sand Blowing in Blow-in Mold Making Machine. 3. An upper and lower blow head capable of blowing molding sand into the upper and lower molding flasks, and a sand magazine capable of blowing and supplying molding sand to the upper and lower blow heads by supplying compressed air from a pressure tank. And a blown mold blowing machine equipped with a compressed air jetting mechanism provided with the upper and lower blow heads for changing the forward direction of the casting sand and promoting fluidization of the casting sand. A method for detecting an abnormal filling and filling, in which a reference pressure curve is preset from the pressure in the pressure tank, the pressure in the upper and lower blow heads, and the filling time of the molding sand, and the actual pressure in the pressure tank, the upper and lower blow
The step of measuring the pressure in the head and the filling time of the molding sand, the pressure in the pressure tank actually measured, the pressure in the upper and lower blow heads and the actual pressure curve is calculated from the filling time of the molding sand and the standard An abnormality detection method for a foundry sand blow filling in a blow-in mold molding machine, which detects an abnormality from a deviation value between a pressure curve and an actually measured pressure curve. 4. The reference pressure curve is set by the pressure in the pressure tank, the pressure in the blow head, and the filling time of the foundry sand, which are obtained from empirical values. Method for Abnormal Filling of Foundry Sand Blowing in Blow-in Mold Making Machine. 5. An upper and lower blower head capable of blowing molding sand into the upper and lower molding flasks, and a sand magazine capable of blowing the molding sand into the upper and lower blow heads by supplying compressed air from a pressure tank. And a blown mold blowing machine equipped with a compressed air jetting mechanism provided with the upper and lower blow heads for changing the forward direction of the casting sand and promoting fluidization of the casting sand. An internal filling abnormality detection system, a storage means for storing in advance a reference pressure curve set by the pressure in the pressure tank of compressed air obtained from empirical values, the pressure in the upper and lower blow heads, and the filling time of the molding sand, The pressure detector in the pressure tank, the pressure detector in the upper and lower blow heads, the detector for the filling time of the foundry sand, the input means for inputting the output from each of these detectors, and the storage means are stored. Was Comparing means for comparing the quasi-pressure curve, the pressure in the pressure tank input to the input means, the pressure in the upper and lower blow heads, and the measured pressure curve from the filling time of the molding sand, the reference pressure curve and the measured pressure A determination means for determining whether or not a deviation value of a curve is equal to or more than an allowable value, and a casting sand blow filling abnormality detection system in a blow type molding machine.