WO2002020195A1

WO2002020195A1 - Heat treating device and heat treating method for casting

Info

Publication number: WO2002020195A1
Application number: PCT/JP2000/006096
Authority: WO
Inventors: Hiroshi Usui
Original assignee: Taiho Industries Co., Ltd.
Priority date: 2000-09-07
Filing date: 2000-09-07
Publication date: 2002-03-14
Also published as: AU2000268739A1

Abstract

A heat treating device and heat treating method capable of scraping off molding sand and core sand while a casting is heat-treated. Apparatuses, each having both an impact mechanism (4) for applying a direct impact to molding sand or a molding (a) and a vibration mechanism (5) for applying a direct vibration, are provided in multiple stages. Whereby, a direct impact and/or direct vibration are applied to molding sand or a molding in a heating room to thereby make it possible to scrape off molding sand and core sand deposited on the surface or inside of the molding while the molding is heat-treated in the heating room.

Description

铸 Heat treatment equipment and heat treatment method for manufactured products

TECHNICAL FIELD The present invention relates to a heat treatment apparatus and a heat treatment method for a prefabricated product, which can remove 铸 -type sand and core sand during heat treatment of the prefabricated product. Background art

Automobile parts, such as engine blocks and cylinder heads, tend to shift from iron to aluminum for the purpose of weight reduction, and their shapes and thickness are becoming more complicated. Such a product is manufactured using a core, cooled to room temperature, cut, glued, and knocked out, and then the binder in the core is baked in a sand sintering furnace to remove the core sand. The method of recovering and then performing heat treatment such as quenching, tempering, and solution treatment was adopted. However, in this method, cooling is performed once after fabrication, so that not only the heat possessed by the fabricated product is wasted, but also processing equipment for cooling and time for cooling are required. On the other hand, an attempt to recover the core sand by oxidatively decomposing or vaporizing the binder while performing heat treatment using a resin with excellent heat disintegration properties as the binder in the core has also been reported in Japanese Patent Publication No. It is proposed in Japanese Patent Application Publication No. 1-501123.

However, the heat treatment apparatus (method) proposed in the above-mentioned Japanese Patent Publication No. Sho 61-501123 has a configuration in which the binder is oxidatively decomposed while maintaining a high oxygen concentration in the furnace. However, in the case of a complex shaped product, the slide pill located inside the product is not peeled off from the main body and the core is not supplied with sufficient oxygen and heat. Sand could not be completely removed and recovered.

Therefore, the present inventors apply vibrations to a rack accommodating the product in the heating chamber, so that the mold adheres to the product while performing the heat treatment. A heat treatment apparatus for peeling off sand and core sand has been proposed in Japanese Patent Application Laid-Open No. Hei 8-7-1735.

However, even with the heat treatment apparatus proposed in the above-mentioned Japanese Patent Application Laid-Open No. 8-71735, there was a case where it was not possible to completely remove sand by vibration alone depending on the shape of the manufactured product. In addition, since the rack takes the weight of the manufactured product, the load on the rack increases as the manufactured product becomes larger. In addition, equipment for applying vibration to the rack was large. In addition, the structure that came into contact with the rack was sometimes damaged.

Therefore, the present inventors diligently studied the problems of the above-described device, and found that the indirect vibration application of transmitting vibrations to the product via the rack is the cause of the problem described above. I found it. In other words, due to indirect vibration, 铸 if the action given to the product is not sufficient, core sand is likely to remain, and if it is too strong, 铸 the product will slip or move in the rack And was easily damaged by contact with the edge of the. Also, depending on the shape of the manufactured product, it was not possible to completely remove the sand in a short time only by adjusting the strength of the vibration. For example, it was not possible to sufficiently cope with the case where high-amplitude vibration with a small amplitude was required. In addition, it was necessary to provide a sand discharge device for the cooling device. It is difficult to completely remove all sand in the furnace, and a cooling system requires a sand discharger. In particular, in a continuous furnace, it was necessary to be able to completely remove sand in a short period of time because the time to apply vibration was short due to the equipment.

Moreover, as described above, the tendency of the shape to be complicated continues and is expected to continue in the future. In addition, hard resin is used for solidifying type I sand and core sand. Since it is difficult to collapse, even a more complicated shaped product, the present inventors have conducted intensive studies on a heat treatment apparatus capable of reliably and quickly removing the 鎵 -shaped sand and core sand, and have found the present invention. Disclosure of the invention

The heat treatment apparatus of the present invention has, in a heating chamber of the heat treatment apparatus, both an impact mechanism that directly impacts on the type III sand or the product and a vibration mechanism that directly vibrates. The devices were provided in multiple stages. Then, while performing heat treatment on the product in the heating chamber, it was possible to peel off the mold sand and core sand adhering to the surface and inside of the product.

Further, the heat treatment method of the present invention may be such that, depending on the shape and the like of the product, a direct impact, a direct vibration, or a direct vibration is applied to the type sand or the product after the direct impact. As a result, the 砂 -type sand and core sand adhering to the surface and inside of the 品 product were removed while the 品 product was heated in the heating chamber.

Heat treatment is performed in the heating chamber of the heat treatment apparatus of the present invention. When the product is heated to a predetermined temperature, the binder in the core near the product is oxidized and decomposed. A multi-stage device (hereinafter referred to as a direct stress acting device) that combines an impact mechanism that applies a direct impact and a vibration mechanism that applies a direct vibration makes it easy and reliable to apply impact and vibration directly to the product. Ni-type sand and core sand can be peeled off. The direct stress acting devices provided in multiple stages may operate only the impact mechanism that directly applies an impact according to the shape of the product, or may operate only the vibration mechanism that directly applies the vibration, or The impact mechanism may be operated in the first stage direct stress device, and the vibration mechanism may be operated in the second stage direct stress device. As described above, the heat treatment apparatus of the present invention can peel off the mold sand and core sand during the heat treatment, and more specifically, the slide chill located inside the product is peeled off from the main body even in the case of a complicated shaped product. Since the core and oxygen are sufficiently supplied, the binder in the core is completely oxidized and decomposed, and the core sand can be completely removed and recovered. Therefore, there is no need to perform knockout by cooling the manufactured product once after manufacturing as in the conventional case, and the number of processes can be reduced and the manufacturing time can be shortened. Also, unlike the method of indirectly applying vibration through a rack, the equipment does not become large and does not damage the product.

Furthermore, since the product introduced into the heating chamber in the heat treatment apparatus of the present invention does not need to be cooled once after the production, it is necessary to cut the gate or continuously connect it. It may be introduced into the heating chamber continuously, and may have a predetermined temperature in the heating chamber within a short time with the retained heat given by the structure, thereby shortening the time of the heat treatment. Alternatively, it may be cooled and then introduced into a heating chamber for heat treatment. Therefore, the heat treatment apparatus of the present invention can heat-treat a large number of products in a short time when a plurality of products are continuously subjected to the heat treatment. Due to these effects, a product can be manufactured in an extremely short time. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side sectional view showing one embodiment of a heat treatment apparatus according to the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a front view showing an impact mechanism of a direct stress acting device. FIG. 4 is a side sectional view thereof, FIG. 5 is a front view showing a vibration mechanism of the direct stress application device, FIG. 6 is a side sectional view thereof, and FIG. (A) is a plan view of a transfer basket in a heating chamber, FIG. 7 (b) is a front view thereof, and FIG. 7 (c) is a side view thereof. BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in more detail with reference to the accompanying drawings.

The continuous heat treatment apparatus shown in Figs. 1 and 2 has a heating chamber (solution furnace) 1 consisting of a heating zone 2 in the first half and a soaking zone 3 in the latter half, and directly above the heating zone 2. A direct stress application device 6 ′ having both an impact mechanism for applying an impact and a vibration mechanism for applying a direct vibration is provided in multiple stages, and the lower end of a shaft 7 extending from each direct stress application device 6 ′ is located inside the heating zone 2. Is facing.

The direct stress application device 6 ′ has a total of eight vertically extending shafts 7 in four rows in the lateral direction and two rows in the front-rear direction, except that the number of shafts 7 is changed. The direct stress acting device 6 having substantially the same configuration is shown in FIGS. The reference numerals in the drawings in the following description are also used in FIGS. 1 and 2.

The embodiment of the impact mechanism 4 shown in FIGS. 3 and 4 has three rows in the lateral direction, There are a total of six vertically extending shafts 7 in two rows, with the lower end 8 of each shaft 7 located inside the heating chamber 1 and the upper end of each shaft 7 located outside the heating chamber 1 It is arranged to be. Each shaft 7 is supported in series by a frame 10 via an air cylinder 19, and the frame 10 can be moved up and down by another air cylinder 11 arranged at the center thereof. It is located in In FIG. 3, reference numeral 12 denotes a frame, and reference numeral 13 denotes a partition, which assists a stable vertical movement of the shaft 7 without hindering the vertical movement of the shaft 7. Reference numeral 14 denotes a basket for holding a total of six pieces of type I sand or artificial product a, the details of which are shown in FIG. The mechanism (part) related to the vibration mechanism 5 described later is intentionally omitted.

Then, in the impact mechanism 4, first, the frame 10 is lowered to an appropriate position by the operation of the air cylinder 11, and is stopped at a position where the lower end 8 of the shaft 7 does not come into contact with the type sand or the product a. Subsequently, by operating each air cylinder 9, each shaft 7 is repeatedly moved up and down continuously, and the lower end 8 of each shaft 7 is caused to collide with the top of the type sand or the product a. Can act. At this time, the strength of the impact on the 砂 -type sand or the 品 a ’and the pitch (action interval) thereof can be easily adjusted by controlling the operation of the air cylinder 9.

In the embodiment of the vibration mechanism 5 shown in FIG. 5 and FIG. 6, air shockers 15 are respectively arranged at the upper ends of the six shafts 7 extending in the vertical direction. The other configuration is the same as that of the impact mechanism 4 described above. The mechanism (part) related to the above-mentioned impact mechanism 4 is intentionally omitted.

Then, in the vibration mechanism 5, the frame 10 is first lowered to an appropriate position by the operation of the air cylinder 11, and the lower end 8 of the shaft 7 is brought into contact (pressure contact) with the top of the type sand or the product a. To stop. Subsequently, by operating the air shock forces 115, vibration can be applied from the lower end 8 of each shaft 7 to the top of the 鐽 -shaped sand or the structure a, and the vibration can be directly applied. At that time, the vibration intensity and pitch of type 砂 sand or 品 product a The adjustment of the distance can be easily performed by controlling the operation of the air shocker 15. Note that an electric vibrator may be used instead of the air shocker. Alternatively, a crankshaft (eccentric shaft) may be used. In addition, the vibration mechanism is not limited to the one that acts on the top of the 砂 -type sand or the 铸 a ’, and may be configured to support in the left-right direction and apply vibration in the lateral direction.

As described above, the direct stress application device 6 of the illustrated embodiment can drive the shaft 7 in two kinds of modes, and can directly apply stress (shock, vibration) to the 錶 type sand or the 铸 product a. it can. Therefore, it is possible to completely remove sand in a short time by appropriately adjusting the strength of impact and vibration and the pitch (action interval) according to the shape of the product. Therefore, the product a and the basket 14 do not come into contact with each other and are not damaged. Also, for example, it is possible to very easily cope with a case where vibration of eight pitches having a small amplitude is required.

Further, in the illustrated embodiment, hoppers 16 for receiving peeled-off 铸 -shaped sand and core sand are provided side by side over the entire heating chamber 1, and a screw conveyor 1 is provided at the bottom of each hopper 16. 7 is installed, and the sand and core sand that have been peeled off by impact or vibration are discharged to the outside by this screw conveyor 17. It should be noted that sand may be discharged by a double damper instead of the screw conveyor.

In the heating zone 2 in the heating chamber 1, hot air heated by radiant tube burners 18 provided at appropriate intervals is blown by a circulation fan 19 to perform a high-temperature heat treatment. In addition, a heat-resistant screen is installed at the top of the hopper 16 to control the size of the sand falling into the hopper 16 so that the resin can be easily burned by the radiant tube burner 18 installed in the hopper 16. It is devised.

Since the discharged sand has substantially disappeared due to the oxidative decomposition of the binder, it can be mixed with a new binder and reused as a 铸 -type core.

In the meantime tropical zone 3, radiant chis The structure is such that the hot air heated by the Ube burner 18 is heated by circulating the hot air in the flow direction by the air circulation devices 19 provided at the front and rear ends, and the heating conditions are different from those of the heating zone 2 described above. The article can be heat treated. Next, a transfer mechanism of the manufactured product a in the heating chamber 1 will be described. At the front end of the heating chamber 1, an extrusion-type transfer device 20 is provided, and pushes the baskets 14 to the front row of the heating zone 2 of the heating chamber 1 at appropriate intervals. The hole 21 provided in the basket 14 is a hole into which an operating rod such as a forklift is inserted in an operation such as rotation at that time. Although the roller 22 supporting the lower surface of the basket 14 in the heating zone 2 does not have a drive source itself, the baskets 14 are extruded one after another at appropriate intervals by an extrusion type conveying device 20. The baskets 14 on the heating zone 2 are sequentially intermittently pushed and transported accordingly. That is, in the heating zone 2, since the impact mechanism 4 and the vibration mechanism 5 apply a shock or vibration directly to the top of the 铸 type sand or 铸 product a as described above, the 铸 type sand or铸 It is preferable to move the product a intermittently. In short, the movement and stop are repeated intermittently, so that impact or vibration is applied from the lower end 8 of the shaft 7 during stop, and the lower end of the shaft 7 is separated from the 铸 -type sand or the product a during movement. To keep. In addition, since the roller 14 or the skid rail is laid on the lower surface of the basket 14, it is possible to easily plan a strength enough to withstand a hot shock even from the upper side.

On the other hand, the leveling zone 3 has a configuration in which the rollers 23 that support the lower surface of the basket 14 themselves have a drive source (not shown) and are continuously conveyed at a constant speed.

At the rear end of the heating chamber 1, an air-cooled cooling chamber 25 and a water-cooled cooling chamber 30 are provided.

An air duct 26 is provided in the air-cooled cooling chamber 25, and the product a is quenched (cooled) by injecting air at an appropriate temperature. Since only a small amount of sand adheres (remains) on the surface of the product a, there is no need to provide a sand discharging device, but this is not particularly limited. Air injection nozzle By considering the shape, the quenching effect and the sand removal effect can be improved.

The water-cooled cooling chamber 30 is provided with an elevating device 31 and a water tank 32, and the product a is quenched (cooled) by being immersed in the water tank. Since only a small amount of sand adheres (remains) on the surface of the product a, it is not necessary to provide a sand discharging device, but this is not particularly limited.

In the cooling chamber 30, the product a together with the basket 14 was immersed in the water tank 32, in order to wash away the sand remaining inside due to the evaporating steam and the vertical movement.

Generally, American automobile manufacturers make sand molds for both outer molds and cores and implement gravity manufacturing, and Japanese manufacturers often produce only cores with sand molds. In addition, there are various types of lump shapes ranging from extremely complex to relatively simple, and various types of binders for sand molds are used, from those that can be burned at low temperatures to those that can be burned at relatively high temperatures. . Therefore, it is only necessary to appropriately select an aspect according to various cases, to collapse the type sand and core sand, and to peel off the sand from the product.

• Examples where sand can be removed by direct impact only;

A relatively small engine block, such as an in-line four-cylinder sand type, can discharge sand only by direct vibration. Sand may remain inside the cylinder during indirect vibration.

• Examples of direct impact + direct vibration that can discharge sand;

A large engine cylinder head with sand type cannot remove sand by direct impact only or direct vibration alone, leaving a considerable amount of sand inside the cylinder. To sand.

Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and can be implemented in any way unless the configuration described in the claims is changed. . Industrial applicability As described above, the heat treatment apparatus of the present invention can directly apply impact and vibration while performing heat treatment on a product in a heating chamber, so that the type sand and core sand adhering to the product can be removed. It can be peeled off more reliably and in a shorter time.

The heat treatment apparatus and the heat treatment method of the present invention can be used to adjust the strength and strength of shock and vibration and the pitch (action interval) appropriately according to the shape of the manufactured product, etc. It can be applied to heat treatment of products and has extremely high practical value.

In addition, the heat treatment apparatus of the present invention has almost no relation to the weight of the target product, etc., because the impact mechanism that applies a direct impact and the vibration mechanism that applies a direct vibration are compared with the conventional mechanism that applies an indirect vibration. It can be designed to be extremely compact.

Claims

The scope of the claims

1. In the heating chamber, a multi-stage device that has both an impact mechanism that directly impacts on the sand or the product and a vibration mechanism that gives direct vibration is installed in multiple stages, and the production is performed while heating the product in the heating chamber. A heat treatment device that can remove mold sand and core sand adhering to the surface and inside of products.

2. In the heating chamber, direct impact and Z or direct vibration are applied to the sand or the structure, and the sand is attached to the surface or inside of the structure while heating the structure in the heating chamber. Heat treatment method to peel off and core sand.