JPH09280994A - Measuring head for permeability measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively seal between a casting mold having rough surface and a measuring head by providing a hollow member radially flexible at the inside or outside of the head, a supply and exhaust passage for supplying and exhausting fluid into and from the member and a measuring fluid supply passage for supplying the fluid for measuring the permeability at a molten material pouring port side. SOLUTION: An elastic member 12 for forming an elastically deformable hollow member made of resin member such as rubber or foamable urethane is mounted on the outer periphery of the end 10a of the housing 10 of a measuring head S by fittings 14, 16, and a hollow chamber 18 is formed between the member 12 and the hosing 10 of the head S. An air supply and exhaust passage 20 and a connecting passage 22 are formed at the chamber 18 in the housing 10. The air is supplied to the chamber 18 to expand the member 12 to bring it into contact with the molten material pouring port of a casting mold. Since the member 12 itself is deformed in response to the surface shape of the inside of the port, and brought into surface contact, and hence effectively seals between the inside of the port of the mold of rough surface and the head S. Accordingly, the air is not leaked, and accurate permeability measurement can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring head of an air permeability measuring device for measuring the air permeability of a mold made of foundry sand.

[0002]

2. Description of the Related Art Conventionally, a mold made of mold sand has a structure shown in FIG.
There are the following. Such molds are, for example, published by Maruzen Co., Ltd. (published date: May 20, 1973), "Foundry Handbook" (revised 3rd edition), written by Japan Foundry Association, 1519-.
It is manufactured by a ceramic shell molding method or the like of the investment casting method as described on page 1540 (in particular, see page 23.2 on page 1520). This casting method is used when it is desired to mass-produce a large number of parts.

In this casting method, a plurality of wax prototypes for one part are produced, these wax prototypes are assembled to produce a tree-shaped wax die, and the tree-shaped wax die is mixed with a binder. A mold is produced by covering with mold sand, heating and baking the mold sand, and melting the wax inside.
FIG. 5 is a cross-sectional view of the mold produced in this way, 1 is a mold, 2 is mold sand that has been hardened by baking, 3 is a part (mold) in which a part is cast, 4 is a pouring port for pouring, A plurality of parts 3 in which parts are cast from the pouring port 4 are provided in a tree shape.

[0004]

When such a mold capable of casting a large number of parts at a time is used, a large number of a large number of parts can be manufactured at one time, but if a crack occurs in the mold, all of the many parts are defective. There was a case where it became. However, in the past, such mold cracking was not detected, and when a mold cracked, the mold sand used when the operator made the next mold based on his own experience, etc. The actual situation is to take measures such as increasing the number of times the product is applied so that defects will not occur in the mold to be manufactured next.

Further, there is no measuring head capable of measuring the air permeability of the mold as shown in FIG.

[0006]

In order to solve the above-mentioned problems, in the first aspect of the present invention, in the measuring head of the air permeability measuring apparatus of the present invention, a mold having a pouring port for pouring is formed. In the measuring head of the air permeability measuring device for measuring the air permeability, a hollow member which is attached to the inside or outside of the measuring head and is expandable and contractible in the radial direction, and a supply / discharge passage for supplying / discharging a fluid into / from the hollow member, It is characterized in that a measuring fluid supply passage for supplying a fluid for measuring air permeability is provided on the pouring port side.

In the second aspect, the hollow member is
The hollow member is attached to the outside of the measuring head when the measuring head is mounted inside the pouring port. When the measuring head is mounted outside the pouring port, it is mounted inside the measuring head. When the measurement head is attached to the pouring port, when the fluid is supplied from the supply / discharge passage, the expandable / contractible hollow member expands, and the hollow member and the surface of the pouring port are in surface contact with each other to perform sealing. In this state, a fluid for measuring air permeability is supplied from the measurement fluid supply passage to measure air permeability.

According to the second aspect of the present invention, the hollow member is made of rubber or foaming resin, so that the hollow member is easily deformed according to the shape of the surface of the pouring port, and the sealing property is improved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a measuring head S of an air permeability measuring device according to an embodiment of the present invention.
An elastic member 12, which is an elastically deformable hollow member made of a resin member such as rubber or foaming urethane, is attached to the outer periphery of the tip portion 10a of the housing 10 of the measuring head S by metal fittings 14 and 16. A hollow chamber 18 is formed between the member 12 and the housing 10 of the measuring head S.

Further, in the housing 10, an air supply / discharge passage 2 for supplying / discharging air to / from the hollow chamber 18 is provided.
0, the communication passage 22 that connects the front end portion 10a and the rear end portion 10b
Are formed. Next, FIG. 3 shows an overall view of the air permeability measuring device to which the measuring head S shown in FIG. 1 is attached.

Reference numeral 40 denotes an air permeability measuring device. This air permeability measuring device 40 is connected to the hollow chamber 18 through the supply / discharge passage 2.
Fluid control unit 50 that supplies and discharges air to zero
And an air permeability measuring unit 60 for supplying air for air permeability measurement into the mold 30 through the communication passage 22. The fluid control unit 50 includes the hollow chamber 1
Air supply / discharge device 52 for supplying and discharging air into
And an air supply / discharge device 52 and a switching valve 54 provided between the air supply / discharge passage 20 and opening / closing both passages. When air is supplied to the hollow chamber 18 by the fluid control unit 50, the elastic member 12 expands as shown by a dotted line 12a in FIG.

The air permeability measuring unit 60 includes a measuring air generator 62 for generating measuring air, a constant pressure controller 64 for controlling the air generated by the measuring air generator 62 to a constant pressure, and An air flow rate measuring device 66 for supplying air for measuring air permeability to the communication passage 22 and measuring air permeability of the mold 30.

The air flow rate measuring device 66 has a constant pressure introducing portion 661a for introducing constant pressure air supplied from the constant pressure controller 64 on one side and a connecting portion 661b connected to the communication passage 22 of the measuring head 10 on the other side. It is composed of a hollow housing 661 in which is formed, a diaphragm 662 provided in the housing 661, and a sensor 663 that detects a differential pressure of air before and after the diaphragm 662. The air permeability of the mold 30 can be measured by detecting the differential pressure across the throttle 662 with this sensor 663.

The operation of measuring the air permeability of the mold having the above structure will be described with reference to FIG. The measuring head S is inserted into the pouring port 32 of the mold 30 in a state where air is not supplied into the hollow chamber 18 of the measuring head S, that is, the elastic member 12 is not expanded (dotted line 12b).

Next, the switching valve 54 of the fluid control unit 50.
Is operated to open the passage, the air supply / discharge device 52 is operated to generate air, and the air is guided to the hollow chamber 18 via the supply / discharge passage 20. Then, the elastic member 12 expands as shown by the solid line 12a in FIG. 3, and the elastic member 12 and the inside of the pouring port 32 of the mold 30 come into surface contact with each other, and thus sealing can be performed. After the sealing is completed in this way, the switching valve 54 is operated to close the passage to prevent the air in the hollow chamber 18 from leaking to the outside, and the air supply / discharge device 52 is operated to stop the generation of air.

As described above, in the state where the measuring head S is sealed and attached to the pouring port 32 by the elastic member 12,
The mold 3 from the air permeability measuring unit 60 via the communication passage 22.
Air for measuring air permeability is supplied to the inside of 0 and the supplied air passes through the mold 30 and is discharged to the outside air 6
By detecting the pressure difference around 62 with the sensor 663,
The air permeability of the mold 30 is measured.

After the measurement of the air permeability, the switching valve 54 is operated to open the passage so that the air is discharged to the atmosphere through the air supply / discharge device 52. In this way, when the air in the hollow chamber 18 is discharged to the atmosphere, the elastic member 1
2 returns to the original state shown by the dotted line 12b. In this state, the measurement is completed by removing the measuring head S from the pouring port 32 of the mold 30.

As described above, when air is supplied to the hollow chamber 18, the elastic member 12 expands and the pouring port 3 of the mold 30 is filled.
Contact the inside of 2. At this time, the elastic member 12 itself is deformed according to the surface shape inside the oil injection port 32 and comes into surface contact, so that the inside of the pouring port 32 of the mold 30 having a rough surface and the measurement head S can be reliably sealed. it can. Therefore, the air for measuring the air permeability does not leak from the mounting position of the measuring head S to the outside, so that the air permeability can be accurately measured.

FIG. 4 shows a measuring head 70 according to another embodiment. This measuring head 70 is different from the measuring head 10 shown in FIG. 1 in that it is attached to the inside of the pouring port of the mold 90 and is attached to the outside 94 of the pouring port 92 of the mold 90. This measuring head 70 is used when the diameter of the pouring port 92 of the mold 90 is smaller than the diameter of the measuring head 70,
The measuring head S shown in FIG.

On the inner circumference 74 of the large-diameter portion 72 of the measuring head 70, an elastic member 76 which is an elastically deformable hollow member made of rubber, foaming urethane or the like is provided with a metal fitting 78 and a metal fitting 80.
Is attached by the elastic member 76 and the measuring head 70.
A hollow chamber 82 is formed between the inner circumferences 74 of the. With this configuration, the insertion portion 88 of the measuring head 70 is inserted into the pouring port 92 of the mold 90 as shown by the dotted line. Next, the hollow chamber 82
Air is supplied to expand the elastic member 76, and the elastic member 76 is brought into surface contact with the outer side 94 of the pouring port 92 to perform sealing.

In this way, when air is supplied to the hollow chamber 82, the elastic member 76 expands and the pouring port 9 of the mold 90 is filled.
The outer side 94 of the pouring port 92 of the mold 90 having a rough surface because the elastic member 76 itself is deformed and comes into surface contact according to the surface shape of the outer side 94 of the oil filling port 92 while being in contact with the outer side 94 of 2.
The measuring head 70 can be reliably sealed between the measuring head 70 and the measuring head 70, and the measuring head 70 can accurately measure the air permeability.

[0022]

As described above, according to the present invention, after the measuring head is mounted inside or outside the pouring port of the mold,
Fluid is supplied to the hollow member attached to the measuring head to expand it, and the hollow member comes into contact with the inside or outside of the pouring port of the mold, and the hollow member deforms according to the surface shape inside or outside the pouring port. Surface contact with each other, it is possible to reliably seal between the mold having a rough surface and the measuring head.
Further, by using a resin such as rubber or foaming urethane for the hollow member, the sealing property can be further improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a measuring head according to an embodiment of the present invention.

2 is a II of FIG. 1 of the measuring head according to the embodiment of the present invention.
It is a II sectional view.

FIG. 3 is an overall view of a mold air permeability measuring device including a measuring head according to an embodiment of the present invention.

FIG. 4 is a diagram showing a measuring head according to another embodiment of the present invention.

FIG. 5 is a diagram for explaining a conventional technique.

[Explanation of symbols]

 S, 70 Measuring head 10 Housing 12,76 Elastic member 18,82 Hollow chamber 20,84 Supply / drain passage 22,86 Communication passage 30,90 Mold 32,92 Pouring port 40 Air permeability measuring device 50 Fluid control unit 60 Air permeability measurement Unit 663 sensor

Claims (2)

[Claims] 1. A measuring head of an air permeability measuring device for measuring the air permeability of a mold in which a pouring port for casting is formed, which is a hollow attached to the inside or outside of the measuring head and capable of expanding and contracting in the radial direction. A member, a supply / discharge passage for supplying / discharging a fluid to / from the hollow member, and a measurement fluid supply passage for supplying a fluid for measuring the air permeability to the pouring port side. Measuring head of the device. 2. The measuring head of the air permeability measuring device according to claim 1, wherein the hollow member is made of rubber or foaming resin.