JPH05309442A - Test method for molding sand filling up - Google Patents

Abstract

PURPOSE:To appropriately grasp a filling condition of molding sand and to improve a yield of casting, even though a lost foam pattern has a complicated shape such as unevenness and curved part. CONSTITUTION:When molding sand is filled around the lost foam pattern 31 in the metal mold 4 with vibrated, the pressure sensors 32A-32G are arranged at plural places of the lost foam pattern 31, the sand pressure applied to the lost foam pattern 31 resulting from filling of molding sand is measured by these sensors 32A-32C to obtain the pressure distribution data from the pressure measured value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding sand filling test method used for filling a molding sand having a relatively low viscosity around a fugitive model.

[0002]

2. Description of the Related Art As is well known, the method of casting a fusible model using relatively low-viscosity molding sand (dry sand) is simple in principle, but in reality The strength evaluation of the molded mold is a problem. That is, it is necessary to pay attention to the filling state of the foundry sand. Generally, in the case of filling the molding sand, the molding sand filled in the metal frame and the metal frame is three-dimensionally vibrated by a vibrating machine to compact the molding sand to have an optimum density, The evaluation of the filling state is performed depending on the experience of the site worker.

[0003]

However, according to the above-mentioned conventional structure, since the evaluation of the filling state of the foundry sand is left to the experience of the site worker, the disappearance model has a complicated shape, for example, an uneven portion. When it has a curved portion or a curved portion, it is difficult to accurately grasp the filling state of the molding sand, and it is inevitable that the filling density of the molding sand varies at various points of the disappearance model. If the pressure (sand pressure) at the time of filling the foundry sand is too large, the model may be deformed when a disappearing model made of a foaming resin or the like is used. On the other hand, if the pressure is too small, the molding sand will be insufficiently filled, resulting in casting defects. As described above, since the filling state of the casting sand cannot be accurately grasped, the current state is to inspect and analyze the surface state of the casting by injecting the molten metal into the disappearing model and then disassembling the mold.

The present invention has been made in order to solve the above-mentioned conventional problems. Even if the shape of the vanishing model is complicated, the filling state of the foundry sand is precisely grasped. Therefore, it is an object of the present invention to provide a foundry sand filling test method that can contribute to the prevention of defective casting.

[0005]

In order to achieve the above object, the casting sand filling test method of the present invention uses a casting sand having a relatively small viscosity while vibrating a metal frame containing a vanishing model. When filling the periphery of the model, a plurality of pressure sensors are attached to the predetermined points of the fugitive model, and the pressure to the predetermined points of the fugitive model at the time of filling the molding sand is measured by these pressure sensors, and these pressure measurement values are measured. The pressure distribution data is obtained from.

[0006]

With the above structure, the fugitive model to which a plurality of pressure sensors are attached is housed in the metal frame on the movable table in the foundry sand filling device, and the movable table is three-dimensionally placed while the foundry sand is put in the metal frame. When it is vibrated in the direction, the molding sand is filled around the fugitive model. Here, the pressure at each location of the disappearing model at the time of filling the molding sand is measured by each pressure sensor. By inputting these pressure measurement values into a personal computer, for example, pressure distribution data can be obtained, and it is possible to know from this pressure distribution data the optimum filling condition of the foundry sand according to the shape of the vanishing model. it can.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are respectively an overall front view and an overall plan view showing a foundry sand filling apparatus to which a foundry sand filling test method according to an embodiment of the present invention is applied.

In FIGS. 1 and 2, a movable table 3 is attached to a base 1 via a spring 2 as a cushioning member,
It is provided so that it can vibrate in the three-dimensional directions of the Y and Z axes. The movable table 3 has a metal frame 4 placed on the upper part thereof, and clamps 5 for fixing the metal frame 4 are provided at four corners.

A vibrator 6 for vibrating the movable table 3 in the horizontal X-axis direction is provided on one side of the movable table 3, and on the other side of the movable table 3,
A vibration exciter 7 for vibrating the movable table 3 in the horizontal Y-axis direction is provided. Further, the X-axis shaker 6 and the Y-axis shaker 7 are provided via a spring 8 so as to be able to vibrate in any of the three-dimensional X-axis, Y-axis, and Z-axis directions. In addition, the X-axis shaker 6 and the Y-axis shaker 7
Are equipped with an X-axis variable vibration generation motor 9 and a Y-axis variable vibration generation motor 10, respectively. These X-axis variable vibration generation motor 9 and Y-axis variable vibration generation motor 10 are provided.
Are connected to the movable table 3 via an X-axis vibration transmission device 11 and a Y-axis vibration transmission device 12, which transmit only vibrations in one direction. Furthermore, the movable table 3
A Z-axis variable vibration generating motor 13 for vibrating the movable table 3 in the vertical Z-axis direction is provided on the lower surface of the.

Disappearance model 31 housed in the metal frame 4
An example is shown in FIG. The fugitive model 31 is made of foaming resin and is formed into a rectangular shape having a recess 31a. A plurality of pressure sensors 32, such as piezoelectric elements, for detecting the pressure received at the time of filling the molding sand are provided at predetermined places such as the surface of the fusible model 31 and the inner surface of the recess 31a.
(32A to 32G) are attached.

FIG. 4 shows the configuration of the control device 40 for obtaining the data of the pressure distribution from the pressure measurement values obtained by the pressure sensors 32. In FIG. 4, 41 (41A to 41G) is an amplifier for amplifying the output from each pressure sensor 32, and 4
Reference numeral 2 (42A to 42G) is an A / D converter for analog-digital converting the output from the amplifier 41 and taking it into the arithmetic circuit 43. Reference numeral 44 is a computer 4 which converts the data of the pressure measurement value in the arithmetic circuit 43 into a transmission signal.
5 is a serial converter for sending to 5, and 46 is a digital display. Reference numeral 47 is a CRT (cathode ray tube) as a display device for displaying the pressure distribution data obtained by the personal computer 45.
Reference numeral 48 is a keyboard, and 49 is a printer.

Next, the casting sand filling test method having the above construction will be described. The vanishing model 31 to which the pressure sensor 32 is attached is housed in the metal frame 4 placed on the movable table 3, and the cables from the plurality of pressure sensors 32 are bundled and pulled out from the metal frame 4 to obtain the amplifier 41, respectively. Connect to the input end of. In this state, when the molding sand is charged into the metal frame 4 and the variable vibration generating motors 9, 10, 13 of the respective axes in the molding sand filling device are driven, the movable table 3 moves to the X position.
The sand is oscillated in the three-dimensional directions of the axis, the Y axis, and the Z axis, so that the foundry sand is compacted around the fusible model 31 at an optimum density.

At the time of filling the molding sand, a pressure corresponding to the filling state is applied to each portion of the fugitive model 31, and the pressure is measured by the pressure sensor 32. Each pressure sensor 3
The output of 2 is amplified by the amplifier 41, and then the A / D converter 4
At 2, the signal is converted into a digital signal and is taken into the arithmetic circuit 43. The arithmetic circuit 43 temporarily stores the data as a pressure measurement value, which is serially output via the serial converter 44 and input to the personal computer 45, while being numerically displayed by the digital display 46. The digital data taken in by the personal computer 45 is calculated to obtain the data of the pressure distribution, and the data is the CRT 47.
Is displayed on the screen and is also output to the printer 49 as required. The screen display of the CRT 47 is operated by the keyboard.

As described above, since the pressure distribution data for the vanishing model 31 can be known by the CRT 47 or the like, the filling state of the molding sand can be accurately grasped.
In other words, by analyzing this, the disappearance model 3
The filling density of the foundry sand according to the shape and size of No. 1 is known, and it can be applied to the actual molding work to improve the yield of the cast product.

The shape of the fusible model 31 is an example, and various shapes other than this are applicable, and the mounting location of the pressure sensor 32 is optional according to the shape of the fusible model 31. You can set it to.

[0016]

As described above, according to the present invention, when filling the molding sand around the fugitive model in the metal frame while applying vibration, pressure sensors are attached to a plurality of positions of the fugitive model and disappear. Since the pressure of various places when filling the molding sand against the model is measured and the data of the pressure distribution is obtained from the measured pressure, the filling state of the molding sand according to the shape and size of the disappearing model is appropriate. Therefore, it is possible to contribute to the improvement of the reliability of the cast product during the actual molding operation.

[Brief description of drawings]

FIG. 1 is an overall front view showing a foundry sand filling apparatus to which a foundry sand filling test method according to an embodiment of the present invention is applied.

FIG. 2 is an overall plan view showing a foundry sand filling device in the embodiment.

FIG. 3 is a perspective view showing a state in which a pressure sensor is attached to the vanishing model used in the embodiment.

FIG. 4 is a configuration diagram of a control device for obtaining pressure distribution data from a pressure measurement value obtained by a pressure sensor.

[Explanation of symbols]

 4 Gold frame 31 Disappearance model 32A to 32G Pressure sensor

Claims (1)

[Claims] 1. A plurality of pressure sensors are provided at predetermined locations on the fusible model when filling the periphery of the fusible model with a molding sand having a relatively low viscosity while vibrating a metal frame containing the fusible model. A casting sand filling test method, which is characterized in that the pressure is applied to a predetermined portion of a fugitive model at the time of filling the casting sand with each of these pressure sensors, and pressure distribution data is obtained from these pressure measurement values.