JPH06229902A - Hot water flow tester - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a molten metal flow test apparatus which can obtain practically sufficient reliability and does not require troublesome work. [Structure] The holding tube 56 holding the quartz tube 66 is first
The thermocouple 1 is moved down by the drive motor 48.
Based on the signal from 42, the lower end of the quartz tube 66 is stopped at the position where it is immersed in the molten metal 190. Thereafter, the electromagnetic on-off valve 148 of the pressure reducing circuit 146, which has been reduced in pressure to a predetermined pressure reduction value by the vacuum pump 156 in advance, is opened, and the pressure inside the quartz tube 66 is instantaneously reduced via the pressure-resistant hose 94 to suck up the molten metal 190. Liquid flow is evaluated by the suction height.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melt flow tester for molten metal, and more particularly to a tester capable of obtaining practically sufficient reliability and requiring no troublesome work.

[0002]

2. Description of the Related Art For example, precision casting such as lost wax method, vacuum suction casting method in which molten metal is sucked into the mold through stalk by depressurizing the mold, casting mold through stalk by pressing molten metal The low-pressure casting method of injecting molten metal into the interior is widely used for the production of thin-walled castings with complicated shapes. In the production of such thin-walled castings, the flowability of molten metal is It greatly affects the quality. In other casting methods as well, if the flowability of the molten metal is poor, defects such as defective running of the molten metal will occur. If the flowability of molten metal can be predicted, it can be used, for example, in controlling the pressure value and suction time during suction in the above vacuum suction casting method, and in controlling the pressing force in the low pressure casting method. It is possible to prevent the occurrence of defective products due to the variation in the characteristics. It is also possible to control the temperature of the molten metal so as to obtain a predetermined molten metal flowability.

As a method for evaluating the above-mentioned molten metal flowability, generally,
There is known a method of pouring a molten metal into a spirally formed runner and measuring an inflow length until the pouring is stopped by solidification by cooling. FIG. 11 shows an example of such a test apparatus, and a spiral groove 12 is formed on the upper surface of the lower sand mold 10 as shown in FIG.
A flat-plate-shaped upper sand mold 14 is attached so as to be in close contact with the upper surface of the above, so that a spiral runner is formed between the lower sand mold 10 and the upper sand mold 14. A molten metal container 18 is arranged in the upper sand mold 14 via a runner mold 16, and a molten metal 20 is contained in the molten metal container 18. An opening 22 is provided at the bottom of the molten metal container 18, and the opening 22 is always closed by a stopper 24. The stopper 24 is lifted to open the opening 2
When 2 is opened, the molten metal 20 in the molten metal container 18 flows down to the outer peripheral side end of the spiral runner via the runner mold 16.
The metal melt 20 flows into the runner based on the pressure of the molten metal 20 in the melt container 18, and the leading end is solidified by cooling, so that the inflow is stopped. Then, the sand molds 10 and 14 are unmolded, the inflow length of the molten metal 20 is measured, and the molten metal flowability is evaluated by the inflow length.

[0004]

However, such a conventional molten metal flowability evaluation method has a problem that high reproducibility is not always obtained and sufficient reliability that is practically satisfactory cannot be obtained. That is, it is difficult to process the spiral groove so that the cross-sectional area of the runner is constant, and it is difficult to obtain the correlation between the inflow length and the melt flowability,
The measurement results also vary due to machine differences.
Variations in the material and molding state of the sand mold, such as differences in heat conduction, also affect the measurement results. Further, it is difficult to make the pouring conditions constant, such as the flow of the molten metal during pouring, and the measurement results also change due to variations in the pouring conditions.

On the other hand, another problem is that the metal melt in the melting furnace is transferred to a test melt container, or the mold is disassembled to check the inflow length. It also included problems. The work of correctly measuring the length of the spiral is troublesome and error-prone, and the work of removing the solidified spiral metal from the lower sand mold is also troublesome and time-consuming.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a molten metal flow test apparatus which can obtain practically sufficient reliability and does not require troublesome work. It is in.

[0007]

In order to achieve the above object, the first invention is an apparatus for testing the flowability of molten metal, which is (a) quartz arranged vertically. A tube, (b) an elevating means for elevating the quartz tube and immersing the lower end of the quartz tube in the molten metal, and (c) reducing the pressure to a predetermined pressure by a vacuum pump and A decompression circuit to be connected, and (d) the quartz tube is provided in the decompression circuit, and the lower end portion of the quartz tube is controlled to open while being immersed in the molten metal, thereby instantaneously depressurizing the inside of the quartz tube. The quartz tube has an electromagnetic opening / closing valve for sucking the molten metal.

[0008]

In the molten metal flowability testing apparatus as described above, in the depressurizing circuit, the quartz tube is lowered by the elevating means to immerse the lower end portion in the molten metal and then depressurized to a predetermined pressure in advance. When the solenoid valve is opened, the inside of the quartz tube is decompressed and the molten metal is sucked into the quartz tube. The sucked metal melt solidifies immediately by cooling, but the suction length until the rise of the metal melt stops due to solidification, that is, the length dimension from the molten metal surface to the upper end is determined by the pressure of the decompression circuit and the metal. It depends on the flowability of the molten metal. Therefore, if the suction operation is performed with the pressure of the pressure reducing circuit being constant, the molten metal flowability can be evaluated by measuring the suction length.

Here, the quartz tube has a constant composition and stable properties as compared with a metal material, and since variations in inner diameter dimension, wall thickness, etc. can be reduced, the flowability of molten metal and the suction length can be reduced. There is a high correlation between them and there is little variation due to machine difference. Since the coefficient of thermal expansion of the quartz tube is small,
The dimensional change due to the temperature difference is small, the temperature difference of the quartz tube has almost no effect on the measurement result, and the flowability of the molten metal can be evaluated correctly. Further, since the electromagnetic on-off valve decompresses the inside of the quartz tube, decompression conditions such as its opening speed, that is, decompression speed become constant, and high reproducibility is obtained.
From the above, it is possible to obtain the reliability which is sufficiently satisfactory for practical use in evaluating the molten metal flowability.

On the other hand, a quartz tube can be directly inserted into a molten metal such as a melting furnace used for casting for testing.
Since the quartz tube is transparent, it is possible to visually measure the suction length from the outside.Also, the coefficient of thermal expansion of the quartz tube is small, so the temperature in the quartz tube drops to about room temperature and the metal inside the quartz tube shrinks. By doing so, it is possible to easily take out the quartz tube from the quartz tube, and the test can be performed easily and in a short time without any troublesome work.

[0011]

In order to achieve the above-mentioned object, a second aspect of the present invention is to detect a molten metal surface position of the molten metal in the molten metal flow test apparatus according to the first aspect of the present invention. Based on the molten metal level detection means and (f) the molten metal level position detected by the molten metal level detection means, the descent control means for controlling the elevating means so that the lower end of the quartz tube is immersed in the molten metal. And (g) opening / closing control means for controlling the opening / closing of the electromagnetic opening / closing valve after the lower end of the quartz tube is immersed in the molten metal by the descending control means.

[0012]

In this case, the molten metal level detection means detects the molten metal level position, and the elevating means is controlled by the descent control means based on the molten metal level position. The quartz tube is lowered to such a height that its lower end is immersed in the molten metal. Then, in this state, the opening / closing control means controls the opening / closing of the electromagnetic opening / closing valve, and the molten metal is sucked into the quartz tube in accordance with the pressure value of the pressure reducing circuit.

According to such a molten metal flow tester, the quartz tube is automatically immersed in the molten metal, and the electromagnetic on-off valve is opened to suck the molten metal into the quartz tube. Compared to the case of operating the quartz tube to move the quartz tube or opening and closing the solenoid on-off valve, the burden on the operator is reduced and operation mistakes are prevented, making the molten metal flow test easier and faster. You will be told. Also, since the time from the immersion of the quartz tube in the molten metal to the opening of the electromagnetic on-off valve can be made constant, it is possible to prevent the measurement results from being affected by variations in the temperature of the quartz tube and to obtain higher reliability. become.

[0014]

In order to achieve the above-mentioned object, a third invention is the molten metal flow test apparatus of the first invention or the second invention, wherein the metal sucked into the quartz tube is used. It is characterized by having suction length detection means for detecting the suction length of the molten metal.

[0015]

In this way, since the suction length detecting means automatically detects the suction length of the molten metal sucked into the quartz tube, troublesome measurement work is eliminated. It is possible to reduce the burden on the operator and prevent erroneous evaluation of molten metal flow due to measurement error or measurement error.

[0016]

In order to achieve the above object, a fourth invention is the molten metal flow test apparatus according to the first invention, the second invention or the third invention, wherein the quartz tube is It is characterized in that it is detachably held by a holding member that is raised and lowered by the raising and lowering means, and is connected to the pressure reducing circuit via a detachable coupling joint.

[0017]

In this way, since the quartz tube can be easily attached to and detached from the holding member and the pressure reducing circuit, for example, before the metal that is sucked and solidified is taken out, in other words, the metal is removed due to the temperature decrease. By replacing the quartz tube with another quartz tube before shrinking, the molten metal flowability test can be continuously performed, and the quartz tube having a breakage can be easily and quickly replaced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a front view in which a part of a molten metal flow test apparatus 30 according to an embodiment of the present invention is cut away, and FIGS. 2 and 3 are right side views and a part of the molten metal flow test apparatus 30. It is the top view which notched. In these figures,
The main body frame 32 having a rectangular parallelepiped shape can be freely moved on the floor surface 36 by the flexible casters 34 arranged at the four corners of the lower end, and the height adjustments also arranged at the four corners of the lower end can be performed. With the possible adjuster foot 38,
It can be fixedly held in any place.
A pair of handles 40 are attached to the right side surface of the body frame 32, and an operator can move the body frame 32 by gripping the handles 40.

An elevating table 44 is arranged on the body frame 32 via four guide rods 42 so as to be vertically movable. A rack 46 is fixedly mounted on the elevating table 44 in parallel with the guide rod 42, and a pinion (not shown) meshing with the rack 46 is rotationally driven by the first drive motor 48, so that the elevating table 44 is guided by the guide rod 4.
While being guided by 2, it is vertically moved within a movement range of approximately 500 mm. An elevating means is configured to include the rack 46 and the first drive motor 48. On the top surface of the lift 44,
A pair of mounting blocks 50 having a U-shape are provided,
A hollow arm member 52 is attached so as to pass through the inside of the attachment block 50 and protrude substantially horizontally to the left in FIG. The protruding size of the arm member 52 in the left direction can be arbitrarily adjusted within a range of, for example, about 500 mm to 700 mm, and the lock bolt 54 screwed into one mounting block 50 is tightened, whereby the arm member 5 is tightened.
2 is fixed to the lift table 44 so that it cannot move.

A holding cylinder 56 is attached to the lower surface of the tip of the arm member 52 so as to extend downward in the substantially vertical direction. As is apparent from FIG. 4 showing a front sectional view, FIG. 5 showing a left side view, and FIG. 6 showing a plan view, the holding cylinder 56 has a cylindrical shape with an opening on the left side and is fixed to an upper end portion. The upper block 58 is fixed to the lower surface of the arm member 52. Intermediate blocks 60 and 62 are fixed to two intermediate positions of the holding cylinder 56, and a lower block 64 is fixed to the lower end of the holding cylinder 56. This holding cylinder 56 constitutes a holding member,
For example, the length is 900 mm, the outer diameter is 7 mm, and the inner diameter is 5.
The mm quartz tube 66 is detachably held.

The quartz tube 66 is connected in series to a connecting tube 70 via a connecting jig 68. The connecting jig 68 includes a cylindrical member 72 having an inner diameter substantially the same as the outer diameter of the quartz tube 66, and a pair of cap members 74 and 76 screwed to both ends of the cylindrical member 72. The connecting pipe 70 is integrally and air-tightly screwed to 76. The push ring 7 is provided between the lower cap member 74 and the cylindrical member 72.
8 and a heat-resistant O-ring 80 are interposed, and a pressing ring 82 and a heat-resistant O-ring 84 are interposed between the upper cap member 76 and the cylindrical member 72, which are provided on the cap member 74. When the cap members 74 and 76 are respectively tightened to the cylindrical member 72 with the quartz tube 66 inserted into the cylindrical member 72 through the insertion holes, the O-rings 80 and 84 are elastically deformed and brought into close contact with the quartz tube 66. Connection jig 68 and quartz tube 6
6 and 6 are integrally connected. These O-rings 80, 8
4 also has a function of hermetically sealing the space between the quartz tube 66 and the cylindrical member 72, and a heat-resistant O-ring 8 for sealing provided between the cap member 76 and the pressing ring 82.
6, the airtight seal is provided between the connecting tube 70 integrally screwed to the cap member 76 and the quartz tube 66.

The upper end of the connecting pipe 70 has a connecting joint 90 and an L-shaped hose joint 92 which can be detached with one touch.
Is connected to a flexible pressure resistant hose 94 such as a Teflon tube. The connection joint 90 is a connection pipe 70.
A first connecting member 96 that is airtightly connected to the upper end of the first connecting member 96 and a second connecting member 98 that is airtightly connected to the hose joint 92 are provided, and the detachable ring 10 provided on the second connecting member 98 is provided.
By moving 0 in the axial direction, the first connector 9
6 and the second connecting member 98 are attached and detached by a touch, and at the time of connection, the connecting members 96 and 98 are hermetically sealed. Further, the hose joint 92 is tightened with the nut 102 so that the second connector 9
8 is airtightly connected and the nut 104 is tightened to airtightly connect the end portion of the pressure resistant hose 94 to the joint body.

An insertion hole 104 having a diameter larger than that of the detachable ring 100 is formed in the upper wall of the arm member 52, and an insertion hole having a diameter larger than that of the connecting pipe 70 is formed in the lower wall of the arm member 52 and the upper block 58. 106 are formed.
Further, the intermediate block 60 is formed with insertion holes 108 having a larger diameter than the cap members 74 and 76, and the intermediate block 62 and the lower block 64 are formed with insertion holes 110 and 112 having a larger diameter than the quartz tube 66. There is. On the upper surface of the intermediate block 62, a receiving seat 114 having a diameter larger than that of the cap member 74 is formed concentrically with the insertion hole 110.
The quartz tube 66, the connecting jig 68, the connecting tube 70, etc., which are integrally connected, are held in the holding cylinder 56 by the cap member 74 being seated on the receiving seat 114 of the intermediate block 62 from above. At this time, the cap member 76 is positioned in the insertion hole 108 of the intermediate block 60, and the pair of setscrews 116 screwed into the intermediate block 60 are tightened, whereby the quartz tube 66 and the connecting jig 6 are connected.
8, the connecting pipe 70 and the like are attached to the holding cylinder 56 in a non-separable manner.

On the upper wall of the arm member 52, the connecting pipe 7
A notch 118 having a width dimension larger than the diameter dimension of 0 is formed so as to reach the insertion hole 104 from the left end portion of FIG. 4, and the lower wall of the arm member 52 and the upper block 58 are also larger than the diameter dimension of the connecting pipe 70. A notch 120 having a large width is formed so as to reach the insertion hole 106 from the left end portion of FIG. Notches 122 and 124 having a width dimension larger than the diameter dimension of the quartz tube 66 are formed in the intermediate blocks 60 and 62 so as to reach the insertion holes 108 and 110 from the left side of FIG. 4, respectively. Therefore, the pair of setscrews 116 are loosened until the connecting jig 68 reaches the attachment / detachment position between the upper block 58 and the intermediate block 60 as shown by the alternate long and short dash line in FIGS. 4 and 5. The connection jig 6
8, the quartz tube 66, the connecting tube 70 and the like can be integrally lifted, so that they can be extracted to the left in FIG. 4, that is, to the front side in FIG. Accordingly, the first joint of the joint joint 90 is coupled with the joint joint 90 of the detachable detachable type.
It is possible to easily and quickly replace the portion below the connecting member 96, that is, the suction jig 128 including the first connecting member 96, the connecting pipe 70, the connecting jig 68, and the quartz pipe 66.
The width of the left opening of the holding cylinder 56 is determined by the connection jig 6
8 is larger than the diameter dimension.

Within the holding cylinder 56, between the intermediate block 62 and the lower block 64, a pair of guide rods 130 and screw shafts 132 are arranged parallel to the holding cylinder 56, that is, in the vertical direction. . Pair of guide rods 1
A slider 136 having a detection coil 134 is slidably arranged on the screw 30, and a ball nut (not shown) fixedly mounted on the slider 136 is screwed on the screw shaft 132. The screw shaft 132 is a second drive motor 138 with a reduction gear arranged in the intermediate block 62.
Is driven to rotate via a pulley and a timing belt.
6 is vertically moved while being guided by the pair of guide rods 130. An alternating current is passed through the detection coil 134, and an impedance signal SI representing the impedance of the alternating current is supplied.
The presence or absence of metal in the quartz tube 66, that is, the upper end of the molten metal sucked into the quartz tube 66 is detected based on the change in the impedance.

A thermocouple 142 such as platinum-platinum rhodium or alumel-chromel is attached to the lower block 64 downward via a bracket 140.
The thermocouple 142 is for detecting the molten metal surface position of the molten metal based on the change in the detected temperature due to the detection unit 144 being immersed in the molten metal, and outputs a temperature signal ST. Further, the thermocouple 142 is arranged such that the detection unit 144 is located approximately 10 mm above the lower end of the quartz tube 66 when the quartz tube 66 is held by the holding tube 56. With the position of the molten metal surface, the lower end of the quartz tube 66 is immersed in the molten metal for about 10 mm. The thermocouple 142 corresponds to the molten metal level detecting means.

Returning to FIG. 1 to FIG. 3, the pressure resistant hose 94 is
Is a part of the decompression circuit 146, is guided to the main body frame 32 side through the inside of the arm member 52, and is vacuumed via the electromagnetic opening / closing valve 148 and the pipe 150 arranged in the main body frame 32. It is connected to the tank 152. The vacuum tank 152 is further connected to a vacuum pump 156 via a check valve 154.
The pressure is reduced by 6 to a predetermined pressure. A pressure sensor 158 is connected to the pipe 150,
A pressure signal SP indicating the pressure in the pipe 150, that is, the vacuum tank 152 is output, and the vacuum tank 152 is provided with an electromagnetic leak valve 160.

The hot water flow tester 30 constructed as described above is equipped with the control circuit shown in FIG. 7, and the pressure signal SP output from the pressure sensor 158, the thermocouple 142, and the detection coil 134 and the temperature. The signal ST and the impedance signal SI are taken in by the controller 162, respectively.
The controller 162 includes a CPU, RAM, ROM, I /
The first motor drive circuit 16 is configured to include a microcomputer having an O port, an A / D converter, and the like, and performs signal processing according to a program previously stored in the ROM while using the temporary storage function of the RAM.
4, second motor drive circuit 166, pump drive circuit 168
A drive signal to control the operation of the first drive motor 48, the second drive motor 138, and the vacuum pump 156, respectively, and the electromagnetic leak valve 160 and the electromagnetic on-off valve 148 are turned on and off to open and close. Control. The first drive motor 48 and the second drive motor 138 are provided with rotary encoders 170 and 172, respectively.
A first height signal SH1, which represents the height position of the lift 44.
A second height signal SH2 indicating the height position of the slider 136 is supplied to the controller 162.

The controller 162 also has a display / display.
The operation panel 174 is connected. Display / operation panel 174
Is attached to the right side surface of the molten metal flow test apparatus 30, and as is apparent from FIG. 2, a pressure indicator 176 for displaying the pressure in the vacuum tank 152, the suction length of the molten metal, that is, the molten metal surface. Height display 178 for displaying the suction height H from the power source, power switch 180, selection switch 182 for selecting whether to perform the molten metal flow test automatically or manually.
Start switch 184 for automatic test, first drive motor 48, vacuum pump 1 for manual test
A switch group 186 and the like for controlling the operation of 56 and opening / closing the electromagnetic leak valve 160 and the electromagnetic opening / closing valve 148 are provided.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. Prior to the test, as shown in FIG. 1, the molten metal flow test apparatus 30 is moved to the vicinity of the melting furnace 192 of the casting apparatus filled with the molten metal 190 to be subjected to the molten metal flow test. And is positioned by the adjustable foot 38. The melting furnace 192 is used for vacuum suction casting, for example.

In FIG. 8, when the power switch 180 is turned on, it is determined in step S1 whether "automatic measurement" has been selected by the selection switch 182. When "automatic measurement" is selected by the selection switch 182, it is determined in step S2 whether the start switch 184 is turned on, and the start switch 18
When 4 is turned on, steps S3 and thereafter are executed.
In step S3, with the solenoid on-off valve 148 closed,
Based on the pressure signal SP supplied from the pressure sensor 158, the pressure in the vacuum tank 152 is controlled to be a predetermined pressure, for example, −400 mmHg.
Specifically, first, by the vacuum pump 156, −410 m
The pressure is reduced to about mHg, and then the vacuum pump 156 is stopped and the electromagnetic leak valve 160 is opened to set -400.
Leak up to mmHg. This allows the vacuum pump 1
The pressure is adjusted with high accuracy regardless of the pulsation of 56.

When the pressure adjustment in step S3 is completed, the first drive motor 48 is rotationally driven in step S4 to lower the elevating table 44 which is held at the rising end position in advance, and is attached to the elevating table 44. The arm member 52 and the holding cylinder 56 that are being moved are integrally lowered. During this descent, the temperature signal ST output from the thermocouple 142 is sequentially taken in, and the descent is stopped when the detection unit 144 reaches the surface of the molten metal 190 and the detected temperature of the thermocouple 142 rapidly rises. . As a result, the lower end of the quartz tube 66 is immersed in the molten metal 190 as shown by the chain double-dashed line in FIG.

Subsequently, step S5 is executed to control the solenoid on-off valve 148 to open for a preset fixed time, for example, about 3 seconds. When the electromagnetic opening / closing valve 148 is opened, the inside of the quartz tube 66 connected via the pressure-resistant hose 94 is instantly depressurized, and the molten metal 190 is sucked up into the quartz tube 66. Pressure is about -400 mmHg, inner diameter is 5 m
In the present embodiment using the quartz tube 66 of m, a molten metal 190 is used.
Is instantly sucked up and solidifies. The opening time of the electromagnetic opening / closing valve 148 is set such that the molten metal 19
It is appropriately set within a time period longer than the time period during which 0 solidifies and the suction stops, usually about 1 second or less. Although the pressure value slightly changes due to the opening control of the electromagnetic opening / closing valve 148, the vacuum tank is designed in consideration of the length dimension of the pressure-resistant hose 94 and the suction jig 128 so that the change width is about 2 mmHg or less. The size of 152 is set.

Then, step S6 is executed to execute the first
The elevating table 44, the arm member 52, the holding cylinder 56, etc. are integrally raised by the drive motor 48. Also, step S7
Then, the second drive motor 138 is rotationally driven to lower the slider 136 previously held at the rising end position, and the impedance signal S output from the detection coil 134 disposed on the slider 136 is lowered.
The molten metal 1 sucked into the quartz tube 66 based on the impedance change of the detection coil 134
The top edge of 90 is detected. When the slider 136 descends, at the same time, the second height signal SH2 output from the rotary encoder 172 provided in the second drive motor 138 is taken in, and the upper end position of the sucked molten metal 190 is set to the upper end position of the slider 136. Measured as the distance Y from
In the next step S8, the suction height H is calculated by subtracting the distance Y from the separation distance X between the rising end position of the slider 136 and the detection portion 144 of the thermocouple 142. That is, as shown in FIG. 9, the suction height H from the molten metal surface 190 from the molten metal surface can be obtained by subtracting the distance Y from the separation distance X, and was calculated in this way. The siphoning height H is displayed on the height indicator 178 as a physical quantity representing the flowability of the molten metal. Distance X
Is preset. FIG. 9 shows a state in which the lower end of the quartz tube 66 is immersed in the molten metal 190, but even when the quartz tube 66 is pulled up from the molten metal 190, the molten metal 190 in the quartz tube 66 has already been removed. Since it solidifies and adheres to the quartz tube 66, the suction height H
Can be asked.

A molten metal 190 in the quartz tube 66.
Although the solidified metal of 6 shrinks as the temperature drops, the quartz tube 6
Since the coefficient of thermal expansion of No. 6 is smaller than that of metal, the metal in the quartz tube 66 can be easily taken out, and the next molten metal flowability test can be performed in a relatively short time. However, in the case of continuously performing the molten metal flowability test, the suction jig 128 including the quartz tube 66 is lifted and the coupling joint 90 is separated, and then the suction jig 128 is used.
5 may be extracted from the holding cylinder 56 to the front side in FIG. 5, that is, to the left in FIG. 1, and replaced with a new one. When the suction jig 128 is removed from the holding cylinder 56, the connecting pipe 7
The metal in the quartz tube 66 can be removed by inserting an extruding rod or the like from the 0 side.

If "manual measurement" is selected by the selection switch 182, by operating each switch of the switch group 186, for example, after manually adjusting the pressure in the vacuum tank 152 to an arbitrary value, While visually confirming that the lower end of the quartz tube 66 is immersed in the molten metal 190, the first drive motor 48 is manually operated and the electromagnetic on-off valve 148 is manually controlled to open and close to allow the molten metal to enter the quartz tube 66. 1
90 can be aspirated. Also, regarding the measurement of the suction height H, the quartz tube 66 is transparent and has a linear shape, and slag is attached to the outer peripheral surface of the quartz tube 66 at the portion corresponding to the molten metal 190 position. Since it becomes black due to such factors, the worker can easily measure manually by using a measure or the like, as compared with the conventional technique. If the outer peripheral surface of the quartz tube 66 becomes black due to adhesion of slag or the like, it becomes difficult to determine the molten metal surface position during the subsequent measurement. Therefore, when visually measuring the suction height H, the It is desirable that a heat-resistant cylindrical cap be detachably arranged at the lower end of the quartz tube 66 and be replaced every time.

Here, since the molten metal flow tester 30 of this embodiment sucks the molten metal 190, it has a constant composition and stable properties as compared with a metallic material.
Quartz tube 66 that can reduce variations in inner diameter and wall thickness
Is used, a high correlation is obtained between the molten metal flowability and the suction height H, and there is little variation due to machine difference. Since the thermal expansion coefficient of the quartz tube 66 is small, the dimensional change due to the temperature difference is small, the temperature difference of the quartz tube 66 has almost no effect on the measurement result, and the molten metal flowability can be evaluated correctly. In addition, the quartz tube 6 is opened by the electromagnetic opening / closing valve 148.
Since the decompression in 6 is performed, the decompression condition such as the opening speed, that is, the decompression speed becomes constant, and high reproducibility is obtained. From such a fact, it is possible to obtain sufficiently satisfactory reliability in practical use in evaluating the molten metal flowability.

FIG. 10 shows a measurement of the suction height H of the molten metal 190 for casting such as SCS12 using the melt flow tester 30 of this embodiment while changing the temperature of the molten metal. The height H increases substantially linearly as the molten metal temperature increases. Generally, the melt flowability of the molten metal 190 changes according to the melt temperature, and from the result of FIG. 10, the suction height H measured by using the melt flow tester 30 of this embodiment is the melt flowability. It can be seen that a high correlation is obtained with.

Further, in this embodiment, the selection switch 182 is used.
If “automatic measurement” is selected by, the quartz tube 66 is automatically immersed in the molten metal 190, and
Since the molten metal 190 is sucked into the quartz tube 66 by opening 48, when an operator manually operates the first drive motor 48 to move the quartz tube 66 or open / close the electromagnetic opening / closing valve 148. In comparison, the burden on the operator is reduced, operation mistakes are prevented, and the molten metal flowability test is performed more easily and quickly. Quartz tube 66 with molten metal 1
Since the time from the immersion in 90 to the opening of the electromagnetic on-off valve 148 is also substantially constant, the influence of the temperature variation of the quartz tube 66 on the measurement result can be prevented, and the higher reliability can be obtained. Furthermore, since the suction height H is also automatically measured in this embodiment, the troublesome measurement work is eliminated, the burden on the operator is further reduced, and an erroneous hot water flow due to a measurement error or a measurement error occurs. Sexual evaluation can be prevented.

In the present embodiment, of the series of signal processing by the controller 162, the part that executes step S4 corresponds to the descent control means, and the part that executes step S5 corresponds to the opening / closing control means. The portion that executes steps S7 and S8 is the suction length together with the detection coil 134, the screw shaft 132 for moving the detection coil 134 up and down, the second drive motor 138, and the rotary encoder 172 arranged on the second drive motor 138. It constitutes a detecting means.

On the other hand, the molten metal flow test apparatus 30 of this embodiment
Is the molten metal 190 in the melting furnace 192 used for casting.
The test can be performed by inserting the quartz tube 66 directly into the, and since the quartz tube 66 is transparent, it is possible to visually measure the suction height H from the outside. Since the coefficient of thermal expansion is small, if the temperature in the quartz tube 66 contracts due to the temperature drop to room temperature, the metal can be easily taken out from the quartz tube 66. You can do the test at.
Further, the suction jig 128 including the quartz tube 66 is attached to the holding cylinder 56.
In addition to being easily and quickly attachable / detachable to / from the pressure resistant hose 94 by the coupling joint 90, the suction jig 128 can be easily and easily attached in the case where a molten metal flowability test is continuously performed or breakage occurs. It has the advantage that it can be replaced quickly.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above embodiment, the inner diameter is 5 mm.
Although the quartz tube 66 of No. 3 was used, quartz tubes of various other sizes such as a quartz tube having an inner diameter of 10 mm can be used.
The pressure value of the decompression circuit 146 is also -400 mmHg.
A value other than the above may be set, and the pressure value may be set arbitrarily by key operation or dial operation.

In the above embodiment, the selection switch 182 is also used.
When the "automatic measurement" is selected by, the suction height H is measured fully automatically.
The steps 1 to S6 are automatically performed, and thereafter, the suction jig 128 is held in the holding cylinder 56 or removed from the holding cylinder 56, and the operator manually measures the suction height H with a measure or the like. You may be allowed to do so.

Although the quartz tube 66 and the detection coil 134 are moved up and down by using the rack 46 and the screw shaft 132 in the above-mentioned embodiment, other lifting means may be adopted.

Further, although the thermocouple 142 is used as the molten metal level detecting means in the above-mentioned embodiment, it is possible to measure the temperature by measuring the distance by ultrasonic waves or laser, the electrode short-circuit method, the eddy current sensor method, the temperature difference measurement by the infrared camera, etc. Various other molten metal level detection means that utilize the characteristics of metal or the like can be adopted. These molten metal surface detection means do not necessarily have to be provided in the holding cylinder 56, and when detecting the molten metal surface by distance measurement with ultrasonic waves or laser, temperature difference measurement with an infrared camera, for example,
It is also possible to positionally fix the quartz tube 66 to the main body frame 32 or the like at a position vertically separated by a predetermined distance based on the lower end of the quartz tube 66 when the holding cylinder 56 is held at the rising end position. In that case, by measuring the distance to the molten metal surface, the holding cylinder 5 by the first drive motor 48 is determined from the positional relationship with the lower end of the quartz tube 66.
It is sufficient to control the descending stroke of 6.

Further, in the above-mentioned embodiment, the upper end position of the metal sucked into the quartz tube 66 is detected from the impedance change of the detection coil 134, but various other types can detect the presence or absence of the metal without contact. It is also possible to adopt the detection means of. A scale is provided in the vicinity of the quartz tube 66, and these are photographed by a TV camera or the like and subjected to image processing to obtain the distance Y, or directly obtain the suction height H without obtaining the distance Y. It is also possible.

Further, in the above embodiment, the quartz tube 66 is held by the holding cylinder 56 in a vertical posture, but the quartz tube 66 is arranged in a posture inclined from the vertical direction. It does not matter if it is.

Although not illustrated one by one, the present invention can be carried out in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a front view in which a part of a molten metal flow test apparatus according to an embodiment of the present invention is cut away.

FIG. 2 is a right side view of the molten metal flow test apparatus of FIG.

3 is a plan view of the molten metal flow test apparatus of FIG. 1. FIG.

4 is a vertical cross-sectional view of a holding cylinder portion holding a quartz tube in the molten metal flow test apparatus of FIG.

5 is a left side view of a holding cylinder portion holding a quartz tube in the molten metal flow test apparatus of FIG. 1. FIG.

FIG. 6 is a plan view of a holding cylinder portion holding a quartz tube in the molten metal flow test apparatus of FIG.

FIG. 7 is a block diagram illustrating a control circuit provided in the molten metal flow test apparatus of FIG.

8 is a flow chart for explaining the operation of the molten metal flow test apparatus of FIG.

9 is a diagram illustrating the principle of measuring the suction height in steps S7 and S8 of FIG.

10 is a diagram showing a relationship between a suction height and a molten metal temperature measured using the molten metal flow test apparatus of FIG.

FIG. 11 is a sectional view illustrating an example of a conventional molten metal flow test apparatus.

12 is a plan view showing a lower sand mold of the test apparatus of FIG. 11. FIG.

[Explanation of symbols]

 30: Hot water flow tester 46: Rack 48: First drive motor 56: Holding cylinder (holding member) 66: Quartz tube 90: Connection joint 132: Screw shaft 134: Detection coil 138: Second drive motor 142: Thermocouple (Melting surface detection means) 146: Pressure reducing circuit 148: Electromagnetic on-off valve 172: Rotary encoder 190: Molten metal H: Suction height (suction length) Step S4: Falling control means Step S5: Opening / closing control means Steps S7, S8 : Suction length detection means

Claims (4)

[Claims] 1. A device for testing the flowability of a molten metal, comprising a vertically arranged quartz tube, elevating the quartz tube, and immersing the lower end of the quartz tube in the molten metal. And a depressurizing circuit that is depressurized to a predetermined pressure by a vacuum pump and is connected to the quartz tube, and the lower end of the quartz tube is immersed in the molten metal provided in the depressurizing circuit. And a solenoid valve for sucking the molten metal into the quartz tube by instantaneously depressurizing the inside of the quartz tube. 2. A molten metal level detecting means for detecting a molten metal level position of the molten metal, and a lower end of the quartz tube is immersed in the molten metal based on the molten metal level position detected by the molten metal level detecting means. And lowering control means for controlling the elevating means, and opening / closing control means for controlling the opening / closing of the electromagnetic opening / closing valve after the lower end of the quartz tube is immersed in the molten metal by the lowering control means. 1. The molten metal flow test apparatus according to 1. 3. A suction length detecting means for detecting a suction length of the molten metal drawn into the quartz tube.
Alternatively, the molten metal flow test apparatus according to 2. 4. The quartz tube is detachably held by a holding member that is raised and lowered by the raising and lowering means,
The hot water flow test apparatus according to any one of claims 1 to 4, which is connected to the pressure reducing circuit via a detachable connection joint.