EP2590763A1 - Method for making a casting mould, use of a device for recording of thermal radiation during making of a casting mould, and system for making a casting mould - Google Patents

Method for making a casting mould, use of a device for recording of thermal radiation during making of a casting mould, and system for making a casting mould

Info

Publication number
EP2590763A1
EP2590763A1 EP11803899.1A EP11803899A EP2590763A1 EP 2590763 A1 EP2590763 A1 EP 2590763A1 EP 11803899 A EP11803899 A EP 11803899A EP 2590763 A1 EP2590763 A1 EP 2590763A1
Authority
EP
European Patent Office
Prior art keywords
sand body
water
sand
making
casting mould
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP11803899.1A
Other languages
German (de)
French (fr)
Inventor
Tobias BJÖRKLIND
Thomas Lindstedt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Scania CV AB
Original Assignee
Scania CV AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Scania CV AB filed Critical Scania CV AB
Publication of EP2590763A1 publication Critical patent/EP2590763A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/12—Treating moulds or cores, e.g. drying, hardening
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/56—Investigating or analyzing materials by the use of thermal means by investigating moisture content

Definitions

  • the invention relates to the field of casting of metal items in sand moulds. In particular, manufacture of cylinder heads.
  • Casting of metal often involves using expendable moulds mainly composed of sand.
  • the individual sand grains may be fixed or bonded to one another in various ways.
  • One way of fixing the moulds is to add water glass.
  • Water glass is a solution of potassium silicate or sodium silicate in water. When the water has evaporated, the potassium silicate or sodium silicate fixes the sand grains so that they form a mould in the form of a sand body. The evaporation of the water may be expedited by warming of the sand body.
  • the casting operation is done by pouring molten metal into the sand body.
  • the sand body is broken apart so that the cast item is released.
  • This may entail several problems. The first is that the cast metal surface may have a relatively uneven structure. The second is that sand grains may be trapped in the metal surface. Moreover, the temperature of the metal melt may exceed the sintering temperature of the sand, sintered sand being difficult to remove, particularly from narrow passages in the cast item.
  • Blackwash is refractory and evens out the surface of the sand body.
  • Blackwash consists of refractory particles, e.g. aluminium oxide, alcohol and other additives.
  • the alcohol is removed easily and quickly, before the casting operation, by combustion or evaporation.
  • alcohol-based blackwash has been replaced by water-based blackwash, resulting in problems with regard to removing the water.
  • the water cannot be heated away, nor be evaporated, as easily as alcohol.
  • industrialised casting it is necessary for cost reasons to remove substantially all of the water as soon as possible.
  • a problem in casting of metal items in moulds composed of sand and a water-based refractory coating is thus how to achieve moulds of good and uniform quality quickly, cost-effectively, reliably and automatably.
  • the present invention's method for making a casting mould composed of a sand body and a refractory coating comprises steps of providing a sand body mainly composed of sand, wetting the sand body with a fluid composed of water and at least one additive so that the additive forms a coating on the sand body, warming the sand body so that the water at least partly evaporates, recording a value which represents the sand body's thermal radiation, comparing the recorded value with a predetermined threshold value and evaluating the sand body's water content on the basis of said comparison of the recorded value with the threshold value.
  • the proposed method achieves moulds of uniform and high quality.
  • Each mould made by the method contains very little or no water.
  • An acceptable water content for a given mould can be determined by experiment, followed by applying the method to ensure that the moulds made do not exceed that level.
  • the method is quick, objective and also automatable.
  • the method for making a casting mould composed of a sand body and a refractory coating may comprise the step of adding an inorganic bonding agent to fix the sand body.
  • the bonding agent may be water glass.
  • the water glass is added with advantage in an amount of less than five percent by weight of the sand body.
  • the system comprises a wetting device for wetting a sand body with a fluid composed of water and at least one additive so that the additive forms a coating on the sand body, a warming device to warm the sand body so that the water at least partly evaporates, and a recording device to record a value which represents the sand body's thermal radiation.
  • the recording device may for example be a heat camera with a display screen which shows the sand body's temperature distribution. By aiming the camera at the coated surface and examining the display screen, the user can decide whether the sand body's water content is low enough.
  • the system may further comprise a monitoring device for comparing values recorded by the recording device with a predetermined threshold value and for evaluating the sand body on the basis of said comparison.
  • the warming device is with advantage a microwave oven, which affords the advantage of effectively driving the water content out of the sand body.
  • the system may further comprise a supplementary device for adding water glass to the sand.
  • the wetting device may comprise a bath of fluid consisting of water and at least one additive.
  • the wetting device may be provided with lifting devices capable of gripping and dipping the sand body in a bath of fluid composed of water and at least one additive.
  • Casting mould means here a chemically bonded sand body composed of sand and bonding agent, with a surface coating applied to the sand body.
  • the surface coating is with advantage a water-based blackwash.
  • the fact that the sand body mainly consists of sand means that at least 95 percent by weight of the sand body is sand.
  • Metal material denotes both ferrous metals and non-ferrous metals.
  • Figure 1 illustrates schematically a method for making a casting mould, and also illustrates parts of corresponding systems.
  • a first step 10 is the provision of a sand body 1 .
  • the sand body 1 illustrated here has a U-shaped cross-section, but the sand body, and hence also the mould being made, may be of any desired shape and be configured appropriately to the cast item being made.
  • the mould may be both an external mould and an internal mould, also called a core, and is for once-only use.
  • the first step 10 may comprise mixing of quartz sand and water glass in a mixing device (not depicted).
  • the water glass may be added to the quartz sand by means of a supplementary device (not depicted).
  • the sand body 1 is shaped by means of a forming device (not depicted).
  • the mixture of quartz sand and water glass may be packed into an open mould, followed by a model of the intended cast item being pushed down into the mould to create an imprint in the mixture of quartz sand and water glass.
  • the mixture of quartz sand and water glass may for example be hardened by means of heat and/or carbon dioxide.
  • the first step 10 comprises provision of a ready-made sand body 1 made in a separate process.
  • the sand body is dipped once in water-based liquid blackwash 25a (schematically illustrated as a drop in Figure 1 ).
  • Blackwash is a slurry of ceramic particles in water. Blackwash may comprise up to about 50% water. This blackwash is to form a surface coating on the sand body 1 . If the mould being made is a core, the whole of the sand body 1 is immersed. If an external mould is being made, the only part of the sand body 1 which is dipped is that in which the metal melt is to be poured.
  • the wetting device may comprise a bath of the fluid 25a composed of water and at least one additive.
  • the wetting device may be provided with a lifting device capable of gripping and dipping the sand body in a bath of fluid composed of water and at least one additive.
  • An example of a suitable immersion time is 1 second. If too short a time is adopted, the blackwash layer may be too thin, and too long a time may lead to the sand body 1 absorbing too much water.
  • the thickness of a suitable blackwash layer is about 0.3 mm, measured from the sand body's original structure.
  • the blackwash is absorbed by the sand body 1 , so the blackwash layer even as a mixture of blackwash and sand extends a few thousandths of a millimetre into the sand body.
  • the result is good adhesion between the blackwash and the sand body.
  • the sand body 1 When it has been lifted out of the liquid blackwash 25a, the sand body 1 is held at different angles so that surplus blackwash can run off and the blackwash which clings to the sand body distributes itself in an even thickness across the sand body's surface which has been immersed.
  • An example of a suitable runoff time is 20 seconds.
  • the sand body 1 with its blackwash layer is dried in a microwave oven (not explicitly depicted but illustrated by arrows 35).
  • a microwave oven not explicitly depicted but illustrated by arrows 35.
  • the dried sand body 1 composed of quartz sand and water glass, with its blackwash layer, thus becomes a casting mould.
  • the next step is to check the water content, or the moisture content, of the mould.
  • the drying step 30 will preferably have removed all of the water from the mould, but a small amount of remaining water is acceptable. If too much water remains in the mould, it may change to vapour phase when the hot metal melt comes into contact with the mould. This vapour may damage the mould and/or the item cast.
  • Water remaining in the mould may also dissolve the water glass which binds the sand body 1 , with consequent damage to the mould and hence also to the item cast.
  • a heat camera 45 is used to assess the moisture content of the mould after the drying step 30.
  • the heat camera 45 is aimed at the mould's surface which is coated with blackwash.
  • the camera may be provided with, or be connected to, a separate display screen which shows the temperature of the surface at which the camera is aimed.
  • the operator can relatively easily decide whether the mould is dry enough.
  • the temperature of the mould appears on the display screen in different colours and the operator may at step 50 compare it with a threshold value 55a and draw therefrom a conclusion at step 60 about the dryness of the mould.
  • the conclusion may be either that the mould is dry enough and is therefore approved, 60b, or that its water content is too great and therefore requires further drying, 60a, or scrapping of the mould.
  • the comparison step 50 and the evaluation step 60 may be simplified by the camera being set in such a way that a first colour on the display screen corresponds to a temperature above the threshold value 55a, and a second colour to a temperature below the threshold value 55a.
  • the operator can thus see quickly how large an area (corresponding to the first colour) of the treated surface is above the threshold value 55a.
  • the whole surface should be at a temperature corresponding to the first colour, although small areas of temperature corresponding to the second colour may be acceptable.
  • the camera 45 is connected to a monitoring device 55 which performs the comparison 50 and the evaluation 60.
  • the camera 45 records the mould's temperature and delivers to the monitoring device 55 a value 45a, or more specifically a data amount, which describes the mould's temperature distribution.
  • Said value 45a, or data amount may be an image file containing the temperature of each pixel.
  • the monitoring device 55 compares the value 45a representing the temperature of the mould with a predetermined threshold value 55a. More specifically, the monitoring device 55 determines, pixel by pixel, how many pixels are above the threshold value 55a. On this basis the monitoring device 55 evaluates, at step 60, the water content of the mould. The monitoring device 55 may calculate a value which represents this water content. Finding for example that 97% of the pixels are above 50°C means that the mould is dry enough. This applies for example to Foseco's blackwash PID1 199. The method is adaptable to different kinds of sand bodies and blackwashes, both as regards the temperature threshold value 55a and how large a proportion of the treated surface has to be at a temperature above the threshold value 55a. The evaluation 60 by the monitoring device 55 results in the delivery of a signal which indicates that the respective mould is approved, 60b, or that it is rejected, 60a.
  • the heat camera 45 and the monitoring device 55 may be integrated in one unit.
  • the camera 45 is connected to a unit, e.g. a computer, which serves as monitoring device 55.
  • the monitoring device 55 decides whether the moulds made are approved or rejected, on the basis of the threshold value 55a and the value 45a which represents the thermal radiation of the mould.
  • the monitoring device 55 it also needs to be supplied with an indication of how large a proportion of the treated surface has to be at a temperature above the threshold value 55a.
  • the method, the use of the heat camera, and the system are particularly suited to casting of cylinder heads in that they allow the possibility of varying thicknesses of material in cast items and thin sand portions in cores and moulds.
  • quartz sand and water glass are used for the sand body, and the coating is blackwash. Said sand body with its coating then serves as a casting mould for the cylinder heads.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Mold Materials And Core Materials (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)

Abstract

The invention relates to a method for making a casting mould composed of a sand body(1) and a refractory coating. Said method comprises the steps of -providing(10) a sand body (1)mainly composed of sand, -wetting (20) the sand body (1)with a fluid (25a) composed of water and at least one additive, so that the additive forms a coating on the sand body (1), -warming (30) the sand body (1)so that the water at least partly evaporates, -recording (40) a value (45a) which represents the thermal radiation of the sand body (1), -comparing (50) the recorded value (45a) with a predetermined threshold value (55a), and -evaluating (60) the water content of the sand body (1)on the basis of said comparison (50) of the recorded value (45a) with the threshold value (55a). The invention further relates to a use of a device (45) for recording (40) of thermal radiation during making of a casting mould composed of a sand body and a refractory coating, and a system for making a casting mould composed of a sand body and a refractory coating.

Description

Method for making a casting mould, use of a device for recording of thermal radiation during making of a casting mould, and system for making a casting mould TECHNICAL FIELD
The invention relates to the field of casting of metal items in sand moulds. In particular, manufacture of cylinder heads.
BACKGROUND
Casting of metal often involves using expendable moulds mainly composed of sand. The individual sand grains may be fixed or bonded to one another in various ways. One way of fixing the moulds is to add water glass. Water glass is a solution of potassium silicate or sodium silicate in water. When the water has evaporated, the potassium silicate or sodium silicate fixes the sand grains so that they form a mould in the form of a sand body. The evaporation of the water may be expedited by warming of the sand body.
The casting operation is done by pouring molten metal into the sand body. When the metal has solidified, the sand body is broken apart so that the cast item is released. However, this may entail several problems. The first is that the cast metal surface may have a relatively uneven structure. The second is that sand grains may be trapped in the metal surface. Moreover, the temperature of the metal melt may exceed the sintering temperature of the sand, sintered sand being difficult to remove, particularly from narrow passages in the cast item.
With the object of dealing with the above problems, the surface of the sand body is often coated with so-called blackwash. Blackwash is refractory and evens out the surface of the sand body. Blackwash consists of refractory particles, e.g. aluminium oxide, alcohol and other additives. The alcohol is removed easily and quickly, before the casting operation, by combustion or evaporation. In recent times, alcohol-based blackwash has been replaced by water-based blackwash, resulting in problems with regard to removing the water. The water cannot be heated away, nor be evaporated, as easily as alcohol. In industrialised casting it is necessary for cost reasons to remove substantially all of the water as soon as possible. Its removal may be hindered by the fact that it makes its way into and is absorbed by the sand body. If a significant amount of water remains in the mould at the time when the metal melt is poured in, the pressure arising from vaporisation of the water may result in faulty cast items or even damage to the mould. It is therefore very important to remove substantially all of the water quickly and effectively from the mould and thus ensure that it has reached desired dryness.
The problem of assessing the mould's water content may be entrusted to an experienced operator. However, this imposes great stress on him/her, and the method also becomes relatively slow. Incorrect assessment may result in a mould with too much moisture content leading to faulty cast items. Attempts have been made to weigh the sand mould before and after the coating stage and the drying stage, with the object of ascertaining its water content. However, weighing has not produced satisfactory results, probably because of the small weight of the water relative to that of the sand body.
A problem in casting of metal items in moulds composed of sand and a water-based refractory coating is thus how to achieve moulds of good and uniform quality quickly, cost-effectively, reliably and automatably.
SUMMARY OF THE INVENTION
This problem is solved by the present invention's method for making a casting mould composed of a sand body and a refractory coating. The method comprises steps of providing a sand body mainly composed of sand, wetting the sand body with a fluid composed of water and at least one additive so that the additive forms a coating on the sand body, warming the sand body so that the water at least partly evaporates, recording a value which represents the sand body's thermal radiation, comparing the recorded value with a predetermined threshold value and evaluating the sand body's water content on the basis of said comparison of the recorded value with the threshold value.
The proposed method achieves moulds of uniform and high quality. Each mould made by the method contains very little or no water. An acceptable water content for a given mould can be determined by experiment, followed by applying the method to ensure that the moulds made do not exceed that level. The method is quick, objective and also automatable.
The method for making a casting mould composed of a sand body and a refractory coating may comprise the step of adding an inorganic bonding agent to fix the sand body. This is an environmentally friendly and effective way of fixing the sand. The bonding agent may be water glass. The water glass is added with advantage in an amount of less than five percent by weight of the sand body. The above problem is also solved according to the invention by use of a device for recording of thermal radiation during making of a casting mould which consists of a sand body and a refractory coating, which recording device is used to evaluate the water content of the mould. Making the mould may be done in accordance with the method described above. In particular, water glass may be used to fix the sand body.
Finally, the above problem is solved by a system for making a casting mould composed of a sand body and a refractory coating. The system comprises a wetting device for wetting a sand body with a fluid composed of water and at least one additive so that the additive forms a coating on the sand body, a warming device to warm the sand body so that the water at least partly evaporates, and a recording device to record a value which represents the sand body's thermal radiation.
The recording device may for example be a heat camera with a display screen which shows the sand body's temperature distribution. By aiming the camera at the coated surface and examining the display screen, the user can decide whether the sand body's water content is low enough. Alternatively, the system may further comprise a monitoring device for comparing values recorded by the recording device with a predetermined threshold value and for evaluating the sand body on the basis of said comparison.
The warming device is with advantage a microwave oven, which affords the advantage of effectively driving the water content out of the sand body. The system may further comprise a supplementary device for adding water glass to the sand.
The wetting device may comprise a bath of fluid consisting of water and at least one additive. The wetting device may be provided with lifting devices capable of gripping and dipping the sand body in a bath of fluid composed of water and at least one additive.
Casting mould means here a chemically bonded sand body composed of sand and bonding agent, with a surface coating applied to the sand body. The surface coating is with advantage a water-based blackwash. The fact that the sand body mainly consists of sand means that at least 95 percent by weight of the sand body is sand. Metal material denotes both ferrous metals and non-ferrous metals.
DESCRIPTION OF DRAWING
Figure 1 illustrates schematically a method for making a casting mould, and also illustrates parts of corresponding systems. DETAILED DESCRIPTION
The method according to the invention for making a casting mould composed of a sand body and a refractory coating is described below with reference to Figure 1 . A system for making such a mould is also described.
A first step 10 is the provision of a sand body 1 . The sand body 1 illustrated here has a U-shaped cross-section, but the sand body, and hence also the mould being made, may be of any desired shape and be configured appropriately to the cast item being made. The mould may be both an external mould and an internal mould, also called a core, and is for once-only use.
The first step 10 may comprise mixing of quartz sand and water glass in a mixing device (not depicted). The water glass may be added to the quartz sand by means of a supplementary device (not depicted). Thereafter the sand body 1 is shaped by means of a forming device (not depicted). For example, the mixture of quartz sand and water glass may be packed into an open mould, followed by a model of the intended cast item being pushed down into the mould to create an imprint in the mixture of quartz sand and water glass. The mixture of quartz sand and water glass may for example be hardened by means of heat and/or carbon dioxide.
Alternatively, the first step 10 comprises provision of a ready-made sand body 1 made in a separate process.
In the second step 20, the sand body is dipped once in water-based liquid blackwash 25a (schematically illustrated as a drop in Figure 1 ). Blackwash is a slurry of ceramic particles in water. Blackwash may comprise up to about 50% water. This blackwash is to form a surface coating on the sand body 1 . If the mould being made is a core, the whole of the sand body 1 is immersed. If an external mould is being made, the only part of the sand body 1 which is dipped is that in which the metal melt is to be poured.
The wetting device (not explicitly depicted but represented by the arrow 25) may comprise a bath of the fluid 25a composed of water and at least one additive. The wetting device may be provided with a lifting device capable of gripping and dipping the sand body in a bath of fluid composed of water and at least one additive. An example of a suitable immersion time is 1 second. If too short a time is adopted, the blackwash layer may be too thin, and too long a time may lead to the sand body 1 absorbing too much water. The thickness of a suitable blackwash layer is about 0.3 mm, measured from the sand body's original structure. The blackwash is absorbed by the sand body 1 , so the blackwash layer even as a mixture of blackwash and sand extends a few thousandths of a millimetre into the sand body. The result is good adhesion between the blackwash and the sand body.
When it has been lifted out of the liquid blackwash 25a, the sand body 1 is held at different angles so that surplus blackwash can run off and the blackwash which clings to the sand body distributes itself in an even thickness across the sand body's surface which has been immersed. An example of a suitable runoff time is 20 seconds. In the step 30, the sand body 1 with its blackwash layer is dried in a microwave oven (not explicitly depicted but illustrated by arrows 35). With advantage, this involves using a step oven in which the coated sand body is moved step by step, e.g. on a conveyor belt, from one microwave section to another. Achieving desired drying may for example entail seven steps.
The dried sand body 1 , composed of quartz sand and water glass, with its blackwash layer, thus becomes a casting mould. The next step is to check the water content, or the moisture content, of the mould. The drying step 30 will preferably have removed all of the water from the mould, but a small amount of remaining water is acceptable. If too much water remains in the mould, it may change to vapour phase when the hot metal melt comes into contact with the mould. This vapour may damage the mould and/or the item cast.
Water remaining in the mould may also dissolve the water glass which binds the sand body 1 , with consequent damage to the mould and hence also to the item cast.
According to the invention, a heat camera 45 is used to assess the moisture content of the mould after the drying step 30. The heat camera 45 is aimed at the mould's surface which is coated with blackwash. The camera may be provided with, or be connected to, a separate display screen which shows the temperature of the surface at which the camera is aimed. By examining the display screen, the operator can relatively easily decide whether the mould is dry enough. The temperature of the mould appears on the display screen in different colours and the operator may at step 50 compare it with a threshold value 55a and draw therefrom a conclusion at step 60 about the dryness of the mould. The conclusion may be either that the mould is dry enough and is therefore approved, 60b, or that its water content is too great and therefore requires further drying, 60a, or scrapping of the mould.
The comparison step 50 and the evaluation step 60 may be simplified by the camera being set in such a way that a first colour on the display screen corresponds to a temperature above the threshold value 55a, and a second colour to a temperature below the threshold value 55a. The operator can thus see quickly how large an area (corresponding to the first colour) of the treated surface is above the threshold value 55a. Preferably, the whole surface should be at a temperature corresponding to the first colour, although small areas of temperature corresponding to the second colour may be acceptable.
In a more automated process, the camera 45 is connected to a monitoring device 55 which performs the comparison 50 and the evaluation 60. The camera 45 records the mould's temperature and delivers to the monitoring device 55 a value 45a, or more specifically a data amount, which describes the mould's temperature distribution. Said value 45a, or data amount, may be an image file containing the temperature of each pixel.
The monitoring device 55 compares the value 45a representing the temperature of the mould with a predetermined threshold value 55a. More specifically, the monitoring device 55 determines, pixel by pixel, how many pixels are above the threshold value 55a. On this basis the monitoring device 55 evaluates, at step 60, the water content of the mould. The monitoring device 55 may calculate a value which represents this water content. Finding for example that 97% of the pixels are above 50°C means that the mould is dry enough. This applies for example to Foseco's blackwash PID1 199. The method is adaptable to different kinds of sand bodies and blackwashes, both as regards the temperature threshold value 55a and how large a proportion of the treated surface has to be at a temperature above the threshold value 55a. The evaluation 60 by the monitoring device 55 results in the delivery of a signal which indicates that the respective mould is approved, 60b, or that it is rejected, 60a.
The heat camera 45 and the monitoring device 55 may be integrated in one unit. Alternatively, the camera 45 is connected to a unit, e.g. a computer, which serves as monitoring device 55. In that case the monitoring device 55 decides whether the moulds made are approved or rejected, on the basis of the threshold value 55a and the value 45a which represents the thermal radiation of the mould. In more detail, for the monitoring device 55 to be able to decide, it also needs to be supplied with an indication of how large a proportion of the treated surface has to be at a temperature above the threshold value 55a.
The method, the use of the heat camera, and the system are particularly suited to casting of cylinder heads in that they allow the possibility of varying thicknesses of material in cast items and thin sand portions in cores and moulds. To this end, quartz sand and water glass are used for the sand body, and the coating is blackwash. Said sand body with its coating then serves as a casting mould for the cylinder heads.

Claims

1 . A method for making a casting mould composed of a sand body (1 ) and a refractory coating, comprising the steps of
- providing (10) a sand body (1 ) mainly composed of sand,
- wetting (20) the sand body (1 ) with a fluid (25a) composed of water and at least one additive, so that the additive forms a coating on the sand body (1 ), and
- warming (30) the sand body (1 ) so that the water at least partly evaporates, characterised by
- recording (40) of a value (45a) which represents the thermal radiation of the sand body (1 ),
- comparison (50) of the recorded value (45a) with a predetermined threshold value (55a), and
- evaluation (60) of the water content of the sand body (1 ) on the basis of said comparison (50) of the recorded value (45a) with the threshold value (55a).
2. A method according to claim 1 , in which the recording (40) of the value (45a) which represents the thermal radiation of the sand body (1 ) is done by thermography.
3. A method according to claim 1 or 2, in which the coating is blackwash.
4. A method according to any one of the foregoing claims, in which the wetting (20) is done by a single dipping of the sand body (1 ) in the fluid (25a).
5. A method according to claim 4, in which the dipping lasts less than 5 seconds.
6. A method according to any one of the foregoing claims, comprising the step of adding water glass to fix the sand body before the step of wetting (20) the sand body (1 ) with a fluid (25a) composed of water and at least one additive.
7. A method according to claim 6, in which the water glass is added in an amount of less than 5 percent by weight of the sand body (1 ).
8. Use of a device (45) for recording (40) of thermal radiation during making of a casting mould composed of a sand body and a refractory coating, which device (45) for recording (40) of thermal radiation is used to evaluate (60) the mould's water content.
9. A system for making a casting mould composed of a sand body and a refractory coating, comprising
- a wetting device (25) for wetting (20) the sand body (1 ) with a fluid (25a) composed of water and at least one additive, so that the additive forms a coating on the sand body (1 ), and
- a warming device (35) for warming (30) of the sand body (1 ) so that the water at least partly evaporates, characterised by
- a recording device (45) for recording (40) of a value (45a) which represents the thermal radiation of the sand body (1 ).
10. A system according to claim 9, further comprising
a monitoring device (55) for comparing (50) the recorded value (45a) with a predetermined threshold value (55a) and evaluating (60) the sand body (1 ) on the basis of said comparison (50).
EP11803899.1A 2010-07-07 2011-06-30 Method for making a casting mould, use of a device for recording of thermal radiation during making of a casting mould, and system for making a casting mould Withdrawn EP2590763A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1050744A SE534987C2 (en) 2010-07-07 2010-07-07 Process for producing a mold, use of a device for recording heat radiation in the manufacture of a mold, and systems for producing a mold
PCT/SE2011/050879 WO2012005668A1 (en) 2010-07-07 2011-06-30 Method for making a casting mould, use of a device for recording of thermal radiation during making of a casting mould, and system for making a casting mould

Publications (1)

Publication Number Publication Date
EP2590763A1 true EP2590763A1 (en) 2013-05-15

Family

ID=45441430

Family Applications (1)

Application Number Title Priority Date Filing Date
EP11803899.1A Withdrawn EP2590763A1 (en) 2010-07-07 2011-06-30 Method for making a casting mould, use of a device for recording of thermal radiation during making of a casting mould, and system for making a casting mould

Country Status (4)

Country Link
EP (1) EP2590763A1 (en)
BR (1) BR112012030958A2 (en)
SE (1) SE534987C2 (en)
WO (1) WO2012005668A1 (en)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3771233A (en) * 1972-01-14 1973-11-13 Trw Inc Electrostatic enhancement of evaporation
JPS5257013A (en) * 1975-11-06 1977-05-11 Hitachi Shipbuilding Eng Co Mold moisture measuring process
JPS5581041A (en) * 1978-12-12 1980-06-18 Sintokogio Ltd Mold molding method
JPH10319009A (en) * 1997-05-16 1998-12-04 Sintokogio Ltd Method for measuring moisture content in foundry sand

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2012005668A1 *

Also Published As

Publication number Publication date
SE1050744A1 (en) 2012-01-08
WO2012005668A1 (en) 2012-01-12
BR112012030958A2 (en) 2016-11-08
SE534987C2 (en) 2012-03-06

Similar Documents

Publication Publication Date Title
CN102717029B (en) Casting method for large thin-wall shell aluminium alloy casting
CN107382342B (en) High-temperature-resistant material and preparation method and application thereof
EP0132052B1 (en) Process and mould for casting fragile and/or complex shapes
Yuan et al. The influence of polymer content and sintering temperature on yttria face-coat moulds for TiAl casting
MX2012006584A (en) Foundry mixes containing an organic acid salt and their uses.
Fedorov et al. Effects of process parameters on friability and surface quality in the rapid investment casting process
WO2013138816A2 (en) Thermal distortion tester
Tuttle et al. As-cast surface characterization for steel using disk-shaped chemically bonded sand specimens
FR2709690A1 (en) Consumable model casting process using sand with specific thermal properties.
WO2012005668A1 (en) Method for making a casting mould, use of a device for recording of thermal radiation during making of a casting mould, and system for making a casting mould
Ramrattan et al. Qualification of chemically bonded sand systems using a casting trial for quantifying interfacial defects
US3436235A (en) Colloidal silica compositions containing set indicator
Budavári et al. The Effect of coremaking parameters on the thermal distortion behavior of resin-coated Sand
Ramrattan Evaluating a ceramic resin-coated sand for aluminum and iron castings
US20210346945A1 (en) Thermal management in lost wax casting
Łągiewka Determination of thermophysical properties for selected molding sands
CN108044073B (en) A kind of cold iron with exhaust layer, its preparation method, and the preparation method of casting
El-Sayed et al. Effect of mould type and solidification time on bifilm defects and mechanical properties of Al–7si–0.3 mg alloy castings
CN114672849B (en) Rapid casting method for molten salt electrolytic metal
CN114918369A (en) Manufacturing process of investment casting silica sol mold shell
Jamrozowicz et al. The research of desiccation rates selected protective coating used on mould and sand cores
Romelczyk et al. The Influence of Selected Water and Alcohol Based Coatings on Bending Strength of Foundry Moulds and Cores Manufactured in Furan Technology
EP1027180B1 (en) Investment casting
Fraś et al. The transition from gray to white cast iron during solidification: Part II. Experimental verification
Bihari et al. Effect of process parameters on roughness and hardness of surface and dimensional accuracy of lost wax process casting

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20130207

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20151211