A device and method for measuring fluidity of low-temperature mold material

Abstract

This invention provides a device and method for measuring the flowability of low-temperature molding materials, comprising: at least one mold assembly mounted on a frame, each mold assembly including an upper mold plate and a lower mold plate, the upper mold plate being mounted on the lower mold plate, the lower mold plate having a serpentine runner on its side near the upper mold plate, and the upper mold plate having a runner opening communicating with the sprue of the serpentine runner; a sprue cup mounted on the upper mold plate, composed of two sprue cup plates joined together, the sprue cup communicating with the sprue opening through the runner opening; and a heating device mounted on the frame. The device and method for measuring the flowability of low-temperature molding materials of this invention utilizes a split-type sprue cup, avoiding blind hole structure design. After the experiment, it facilitates cleaning of the wax material inside the sprue cup, preventing incomplete cleaning of blind holes and significantly reducing cleaning time.

Description

Technical Field

[0001] The invention relates to the technical field of investment casting teaching, and in particular to a fluidity measuring device and a measuring method for low-temperature mold materials. Background Art

[0002] Casting is one of the basic processes of modern basic mechanical manufacturing industry. The fluidity experiment involved in the casting process is a basic experimental course for mechanical engineering majors in ordinary colleges and universities. Through fluidity experimental teaching, students can understand the concept, test methods and influencing factors of material fluidity, and have a more comprehensive understanding of the basic knowledge of engineering materials and material forming.

[0003] Traditional fluidity experimental teaching mainly focuses on the field of aluminum alloy materials. Fluidity is one of the casting properties of alloys and directly affects the filling capacity of liquid alloys. The better the fluidity of the alloy, the stronger the filling capacity, and the more it can cast clear contours, thin walls and complex castings. It is also conducive to the floating and discharge of inclusions and gases and the shrinkage compensation during the solidification process. However, alloys with poor fluidity are difficult to fill the mold cavity, and the filling capacity is reduced, which is prone to defects such as insufficient casting, cold shut, pores, and slag inclusions.

[0004] With the development of technology, investment casting has gradually grown. Investment casting, also known as precision casting or lost wax casting, is a process in which a precise fusible model is made of fusible materials (wax, etc.), and several layers of refractory coating are applied on the model. After drying and hardening, the model is formed into an integral shell, and then the shell is heated to melt the lost wax, and then baked at high temperature to form a refractory shell. Liquid metal is poured into the shell, and after cooling, a casting is formed. Compared with other casting methods, the main advantages of investment casting are as follows: the casting has high dimensional accuracy and low surface roughness, and can cast castings with complex shapes, with a general accuracy of 5-7 and a roughness of two Ra25-6.3μm; it can cast thin-walled castings and castings with very small weight, with the minimum wall thickness of investment castings up to 0.5mm and a weight as small as a few grams; it can cast castings with fine patterns, text, and castings with fine grooves and curved pores; the shape and inner cavity shape of investment castings are almost unlimited, and complex parts that are difficult to manufacture by sand casting, forging, cutting and other methods can be manufactured, and some assemblies and welded parts can be directly cast into integral parts after structural improvements, thereby reducing the weight of parts and reducing production costs; there is almost no limit on the type of casting alloy, and it is often used to cast alloy steel parts, carbon steel parts and heat-resistant alloy castings; there is no limit on the production batch, and it can be produced from single pieces to batches. With the development of investment casting technology, the types of mold materials are becoming more and more diverse, and the composition is different. Usually, mold materials are divided into high-temperature, medium-temperature and low-temperature mold materials according to their melting points. The melting point of low-temperature mold materials is about 60°C. The paraffin-stearic acid mixture currently widely used in my country is used as a low-temperature mold material. The melting point of high-temperature mold materials is higher than 120°C. The mold material composed of 50% rosin, 20% ozokerite and 30% polystyrene is a typical high-temperature mold material. The melting point of medium-temperature mold materials is between the above two types of mold materials. The currently used medium-temperature mold materials can basically be divided into two types: rosin-based and wax-based mold materials.

[0005] In the experimental practice teaching of major universities, in order to present the investment casting process to students, some fluidity measurement teaching experiments are usually carried out, and the fluidity measurement teaching experiments are realized by a fluidity measurement teaching device. The pouring cup of the current fluidity measurement teaching device is integrally formed and has many blind holes. After the measurement is completed, the pouring cup is not easy to clean, which increases the workload of cleaning. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a fluidity measuring device and method for low-temperature mold materials. The pouring cup adopts a split type to avoid the blind hole structure design. After the experiment is completed, it is easy to clean the wax material in the pouring cup to prevent the blind holes from being uncleaned, thereby reducing a lot of cleaning time.

[0007] In order to achieve the above purpose, a technical solution adopted by the present invention is:

[0008] A device for measuring the fluidity of a low-temperature mold material comprises: at least one mold assembly, which is arranged on a frame, each of the mold assemblies comprising an upper template and a lower template, the upper template being arranged on the lower template, a serpentine flow channel being arranged on a side of the lower template close to the upper template, a flow channel opening being arranged on the upper template, the flow channel opening being communicated with a pouring inlet of the serpentine flow channel; a pouring cup, which is arranged on the upper template and is formed by splicing two pouring cup plates, the pouring cup being communicated with the pouring inlet through the flow channel opening; and a heating device, which is arranged on the frame.

[0009] Furthermore, the pouring cup plate includes a material cup groove, a feed pipe groove, a connecting hole and a fixing hole groove, the feed pipe groove is located below the material cup groove, two pouring cup plates are spliced ​​into a pouring cup through the connecting hole, the fixing groove is arranged on the base of the pouring cup, the two fixing grooves are spliced ​​into a fixing hole, and the pouring cup is arranged on the mold assembly through the fixing hole.

[0010] Furthermore, the upper template and the lower template are both rectangular plates, and two positioning holes are correspondingly arranged on the upper template and the lower template. The positioning holes on the upper template are located on a diagonal line of the upper template, and the upper template and the lower template are limited by positioning pins and assembled using screws.

[0011] Furthermore, the upper template is a transparent material plate.

[0012] Furthermore, the transparent material plate is one of a PC plate, a plexiglass plate or a PAM plate.

[0013] The present invention also provides a method for measuring the fluidity of a low-temperature mold material, comprising the following steps: S10 test preparation, testing and cleaning a fluidity measuring device for the low-temperature mold material, and assembling a pouring cup and setting it on a mold assembly; S20 configuring a material to be tested in a container, placing the container containing the material to be tested in a heating device, and heating the material to be tested according to the test temperature conditions to melt the material to be tested to obtain a molten material; S30 pouring the melted material to be tested into the mold assembly through the pouring cup, and recording pouring result data, the pouring result data including the surface quality of the sample, the filling length of the sample, and the flow time; and S40 waiting for the mold assembly to cool to room temperature, cleaning the material to be tested and resetting the fluidity measuring device for the low-temperature mold material, and completing the measurement of the material to be tested.

[0014] The above technical solution of the present invention has the following advantages compared with the prior art:

[0015] The invention discloses a fluidity measuring device and method for low-temperature mold materials. The pouring cup is split, and the blind hole structure design is avoided. After the experiment is completed, the wax material in the pouring cup is easy to clean, and the blind hole is prevented from being uncleaned, thereby reducing a lot of cleaning time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The technical solutions and beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0017] Figure 1 The structure diagram of the fluidity measuring device of the low temperature mold material according to one embodiment of the present invention is shown;

[0018] Figure 2 Shown is a structural diagram of a fluidity measuring device for low-temperature mold material according to another embodiment of the present invention;

[0019] Figure 3 Shown is a structural diagram of a mold assembly according to an embodiment of the present invention;

[0020] Figure 4 Shown is a structural diagram of an upper template according to an embodiment of the present invention;

[0021] Figure 5 The figure shows a structural diagram of the connection between the mold assembly and the pouring cup according to an embodiment of the present invention;

[0022] Figure 6 Shown is an exploded view of a pouring cup according to an embodiment of the present invention;

[0023] Figure 7 Shown is a side view of a pouring cup plate according to an embodiment of the present invention;

[0024] Figure 8 The figure shows a structural diagram of a thermostatic box according to an embodiment of the present invention;

[0025] Fig. 9 Shown is an experimental flow chart of a method for measuring the fluidity of a low-temperature mold material according to an embodiment of the present invention.

[0026] Reference numerals

[0027] 1 frame, 2 mold assembly, 21 upper template, 211 runner outlet, 22 lower template, 221 serpentine runner, 222 pouring inlet, 223 straight flow channel, 224 semicircular runner, 225 conveying trough, 23 positioning pin, 24 positioning hole, 3 pouring cup, 31 pouring cup plate, 32 material cup groove, 33 discharge pipe groove, 34 connecting hole, 35 fixing hole groove, 36 butterfly nut, 37 hand-tightening bolt, 38 gasket, 4 heating device, 41 container, 42 second partition net, 43 oven box, 5 storage device, 6 level ruler, 7 electronic scale. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0029] This embodiment provides a device for measuring the fluidity of low-temperature mold materials. Figures 1-2 As shown, it includes: a frame 1, a mold assembly 2, a pouring cup 3, a heating device 4 and a storage device 5. At least one of the mold assemblies 2 is arranged on the frame 1, so that multiple groups of experiments can be carried out at the same time, saving classroom experiment time. The pouring cup 3 is arranged on the mold assembly 2, and the heating device 4 is arranged on the frame 1. The storage device 5 can be arranged on the frame 1 according to the layout requirements of the space, and is located below the mold assembly 2. The storage device 5 is used to store experimental materials or tools and other materials. The storage device 5 is preferably a storage box or a storage cabinet.

[0030] The frame 1, the mold assembly 2 and the pouring cup 3 are all made of stainless steel or aluminum alloy to prevent the equipment from rusting and difficult cleaning. The fluidity measuring device also includes a level 6 and an electronic scale 7. The frame 1 is provided with an adjustment knob, and the level 6 is provided on the frame 1. The adjustment knob cooperates with the level 6 to adjust the level of the mold assembly 2 to avoid the influence of gravity on the fluidity measurement. The electronic scale 7 is used to weigh the experimental materials.

[0031] like Figures 3-4 As shown, the mold assembly 2 includes an upper template 21 and a lower template 22, wherein the upper template 21 is arranged on the lower template 22, and the upper template 21 is a transparent material plate, wherein the transparent material plate is one of a PC plate, a plexiglass plate or a PAM plate. By using a transparent material plate as the upper template, the flow and molding process of the low-temperature mold material in the flow channel of the lower template 22 during the pouring process can be visualized, and the experimental phenomenon can be easily observed. At the same time, combined with the visualized upper template 21, the surface morphology and quality of the sample obtained under different pouring conditions can be intuitively observed. Both the upper template 21 and the lower template 22 are rectangular plates, and two positioning holes 24 are correspondingly arranged on the upper template 21 and the lower template 22. The positioning hole 24 on the upper template 21 is located on a diagonal line of the upper template 21, and the upper template 21 and the lower template 22 are limited by the positioning pin 23 and then assembled with screws.

[0032] The lower mold 22 is provided with a serpentine flow channel 221 on one side close to the upper mold 21, and a flow channel opening 211 is provided on the upper mold 21, and the flow channel opening 211 is communicated with a pouring inlet 222 of the serpentine flow channel 221. The serpentine flow channel 221 includes at least two direct flow channels 223 and at least one semicircular flow channel 224, and the two direct flow channels 223 are connected by the semicircular flow channel 224, and the pouring inlet 222 is connected to one end of the direct flow channel 223. In the design of the direct flow channel 223 and the semicircular flow channel 224, the lengths of the direct flow channel 223 and the semicircular flow channel 224 are usually designed to be fixed integer values, so as to facilitate the measurement and reading of experimental data.

[0033] like Figures 4 to 7 As shown, the pouring cup 3 is formed by splicing two pouring cup plates 31, and the pouring cup 3 is connected to the pouring inlet 222 through the runner opening 211. The pouring cup plate 31 includes a material cup groove 32, a feed pipe groove 33, a connecting hole 34 and a fixing hole groove 35. The feed pipe groove 33 is located below the material cup groove 32. The two pouring cup plates 31 are spliced ​​into the pouring cup 3 through the connecting hole 34. The two material cup grooves 32 are spliced ​​into a cup body. The two feed pipe grooves 33 are spliced ​​into a feed pipe. The upper end of the feed pipe is connected to the cup body, and the lower end of the feed pipe is accommodated in the runner opening. Using the hand-tightening bolt 37 to pass through the connecting hole 34, students can splice the two pouring cup plates 31 by tightening the butterfly nut 36, and the pouring cup 3 can be assembled without the help of tools. The gasket 38 separates the hand-tightening bolt 37 from the pouring cup plate 31 , which can reduce the wear of the pouring cup plate 31 and increase the service life. The gasket 38 can be replaced after wear occurs, saving maintenance costs.

[0034] The fixing groove 35 is arranged on the base of the pouring cup 3, and two fixing grooves 35 are spliced ​​into a fixing hole, through which the pouring cup 3 is arranged on the mold assembly 2. The feed pipe extends into the runner opening 211, and along with the pressing of the pouring cup 3 and the mold assembly 2, the upper mold plate 21 and the lower mold plate 22 are pressed.

[0035] The heating device is a thermostat. Figure 8 As shown, the thermostatic oven includes a second partition 42 and an oven body 43. The oven body 43 can be set to a temperature range of 40-300°C to achieve a constant temperature. The oven body 43 can accommodate four containers 41 at a time through the partition of the second partition 42.

[0036] The present invention provides a variety of fastening methods, which can not only realize fluidity experimental teaching, but also increase students' learning of common mechanical connection methods.

[0037] The present invention also provides a method for measuring the fluidity of low-temperature mold materials, comprising the following steps: S10 test preparation, testing and cleaning the fluidity measuring device of the low-temperature mold material, and assembling the pouring cup 3 and setting it on the mold assembly 2. S20 arranging the material to be tested in the container, placing the container containing the material to be tested in a heating device, and heating the material to be tested according to the test temperature conditions so that the material to be tested is melted to obtain a molten material. S30 pouring the melted material to be tested into the mold assembly 2 through the pouring cup 3, and recording the pouring result data, the pouring result data including the surface quality of the sample, the filling length of the sample, and the flow time. And S40 waiting for the mold assembly 2 to cool to room temperature, cleaning the material to be tested and resetting the fluidity measuring device of the low-temperature mold material to complete the measurement of the material to be tested.

[0038] Wax material formula A and wax material formula B are used as the test materials, and two sets of temperature experiments are carried out for each material. The container 41 is a stainless steel cup. The fluidity measurement method is described as follows: Fig. 9 As shown, the following steps are included:

[0039] S10 Test preparation, check the fluidity measuring device of the low-temperature mold material, clean the dust and debris on the surface of the flow channel, assemble the fluidity measuring device of the low-temperature mold material, and set up two mold assemblies 2 numbered 1# and 2# respectively.

[0040] S20: prepare wax formula A in two stainless steel cups, place the two stainless steel cups with the wax formula A in a heating device 4, number the two stainless steel cups 1'# and 2'# respectively, heat the 1'# stainless steel cup to 65°C and heat the 2'# stainless steel cup to 75°C to obtain a molten material.

[0041] S30: pour the molten material of the 1'# stainless steel cup into the 1# mold assembly 2 through the pouring cup, pour the molten material of the 2'# stainless steel cup into the 2# mold assembly 2 through the pouring cup, and record the pouring result data, which includes the sample surface quality, sample filling length and flow time.

[0042] S40: cleaning the wax material, waiting for the mold assembly 2 to cool to room temperature, cleaning the mold assembly 2 and the wax material formula A on the experimental table, and preparing for the next experiment.

[0043] Repeat step S20, add wax formula B to the two cleaned stainless steel cups, place the two stainless steel cups with the wax formula B in the heating device 4, heat the 1'# stainless steel cup to 65°C and heat the 2'# stainless steel cup to 75°C to obtain molten material.

[0044] Repeat step S30, pour the molten material of 1'# stainless steel cup into 1# mold assembly through the pouring cup, pour the molten material of 2'# stainless steel cup into 2# mold assembly 2 through the pouring cup, and record the pouring result data, which includes the sample surface quality, sample filling length and flow time.

[0045] Repeat step S40, wait for the mold assembly 2 to cool to room temperature, clean the wax material and reset the fluidity measuring device of the low-temperature mold material to complete the fluidity measurement of the wax material formula A and the wax material formula B.

[0046] The molten material starts to be injected from the upper end of the pouring cup 3, flows into the pouring inlet 222 through the pouring cup 3, and then flows in sequence along the serpentine flow channel 221. The molten material flows and fills the mold in the flow channel of the mold assembly 2. The flow process of the wax material can be directly observed through the transparent plate. When the cooling time of the molten material is reached, it is cooled, and finally the filling length after cooling is used to characterize its fluidity. At the same time, combined with the visual transparent plate, the surface morphology and quality of the samples obtained under different casting conditions can be directly observed. The flow lengths of different wax materials at two temperatures are shown in Table 1 below.

[0047] It can be seen from Table 1 that the higher the temperature, the longer the filling length, and different wax formulas have different flow lengths at the same temperature.

[0048] Table 1.

[0049]

[0050] The above description is only an exemplary embodiment of the present invention, and does not limit the scope of patent protection of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of the present invention.

Claims

1. A device for measuring the fluidity of low-temperature mold materials, characterized in that: include: At least one mold assembly is arranged on the frame, each of the mold assemblies comprises an upper mold plate and a lower mold plate, the upper mold plate is arranged on the lower mold plate, a serpentine flow channel is arranged on a side of the lower mold plate close to the upper mold plate, a flow channel opening is arranged on the upper mold plate, and the flow channel opening is communicated with a pouring inlet of the serpentine flow channel; a pouring cup is arranged on the upper mold plate, and is formed by splicing two pouring cup plates, and the pouring cup is communicated with the pouring inlet through the flow channel opening; and a heating device is arranged on the frame; The pouring cup plate includes a material cup groove, a feed pipe groove, a connecting hole and a fixing hole groove. The feed pipe groove is located below the material cup groove. Two pouring cup plates are spliced ​​into a pouring cup through the connecting hole. The fixing groove is arranged on the base of the pouring cup. The two fixing grooves are spliced ​​into a fixing hole. The pouring cup is arranged on the mold assembly through the fixing hole. The upper template is a transparent material plate.

2. The fluidity measuring device for low temperature mold material according to claim 1, characterized in that: The upper template and the lower template are both rectangular plates, and two positioning holes are correspondingly arranged on the upper template. The two positioning holes on the upper template are located on a diagonal line of the upper template. The upper template and the lower template are limited by positioning pins and assembled using screws.

3. The fluidity measuring device for low temperature mold material according to claim 1, characterized in that: The transparent material plate is one of a PC plate, an organic glass plate or a PAM plate.

4. A method for measuring the fluidity of a low-temperature mold material based on the device for measuring the fluidity of a low-temperature mold material according to claim 1, characterized in that: The method comprises the following steps: S10 test preparation, testing and cleaning the fluidity measuring device of the low-temperature mold material, and assembling the pouring cup and setting it on the mold assembly; S20 configuring the material to be tested in the container, placing the container containing the material to be tested in a heating device, and heating the container according to the test temperature condition to melt the material to be tested to obtain a molten material; S30 pouring the melted material to be tested into the mold assembly through the pouring cup, and recording the pouring result data, the pouring result data including the surface quality of the sample, the filling length of the sample and the flow time; and S40 waiting for the mold assembly to cool to room temperature, cleaning the material to be tested and resetting the fluidity measuring device of the low-temperature mold material to complete the measurement of the material to be tested.

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