JPH0623637U - Vehicle wheel molding equipment - Google Patents

Abstract

(57) [Summary] [Purpose] To improve productivity and reduce costs by heating and maintaining the temperature of the material to be processed to a target temperature uniformly in a short time and performing thermomechanical processing online. [Means] In a forming apparatus for forming a vehicle wheel by performing warm spinning on a work material which is formed by forging and is sandwiched by dies on both drive and driven shafts, As the heating means, an induction heating device is arranged coaxially with both the drive and driven shafts for supporting the mold.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 TECHNICAL FIELD The present invention relates to a vehicle wheel forming apparatus for performing a forming process of a one-piece wheel made of an aluminum alloy or a magnesium alloy used for vehicles such as passenger cars, buses and trucks by warm working.

[0002]

[Prior art]

 A spindle for forming a tire wheel from a cylindrical material made of a forged aluminum alloy or magnesium alloy with a concave or H-shaped cross section having a cylindrical portion on the outer periphery, and a spindle having an inner surface molding die at the tip of its drive shaft. It is equipped with a mechanism and a tailstock mechanism that has an inner surface molding die at the tip of the driven shaft facing the mechanism. The circular material is clamped and rotated around the axis, and the outer peripheral surface of the circular material cylindrical portion. Needless to say, a spinning device for performing ironing by pressing a machining roller and molding the inner peripheral surface of the cylindrical portion by the inner surface molding die has been known.

Needless to say, the above-described conventional spinning device performs the spinning process in the cold state, and of course, it is not possible to spin the forged material having good extensibility in the cold state. Although possible, in general, when ironing a casting material that does not have good extensibility, such as an aluminum casting, cracks tend to occur during the ironing process.

For this reason, it is necessary to reduce the processing amount per pass, so the processing man-hours are large and the productivity is poor, and the material is removed from the spinning device during processing, and at least one annealing treatment is performed. After that, the work of reworking is required, and the production efficiency is significantly reduced, causing qualitative concerns and cost pressure on the resulting product. Therefore, in order to solve the above-mentioned drawbacks, the present applicant rotates a circular material having a concave or H-shaped cross section having a cylindrical portion on the outer periphery around the shaft center of the driving and driven shafts while sandwiching the mold. The outer peripheral surface of the cylindrical portion is ironed by switching between a plurality of processing rollers, and a spinning device that drives the rotatable main shaft mechanism and forms the inner peripheral surface of the cylindrical portion with a die mounted on both driven shafts. In Japanese Utility Model Application Laid-Open No. 2-118630, there was proposed a mold and a circular material which rotates while sandwiching the mold and provided with heating means for hot spinning.

In addition to the conventional example 1, a heater is embedded in a spinning die, and a bush made of ceramics is inserted between the inner surface forming die and the rotating shaft and between the processing roll and the mounting shaft. Attempts have been made to extend the life of the bearing by providing a ring to improve the heat insulation property (see Japanese Patent Laid-Open No. 3-184646-hereinafter, conventional example 2), heating the inner surface molding die, and various spinning moldings. A method has also been proposed in which the material is preheated off-line before processing to perform spinning forming processing (see Japanese Patent Laid-Open No. 3-236452, hereinafter, conventional example 3).

Here, in order to refer to the above-mentioned conventional example 1 in describing an embodiment of the present invention described later, its outline will be described with reference to FIG. The spinning device illustrated in the figure has the components necessary for the spinning process, namely, the main shaft mechanism, the tailstock mechanism, the drive shaft, the driven shaft and the molding die held on both shafts, and the plurality of processing rollers. Since it is the same as the conventionally well-known technique, some of them will be omitted in the figure. In the figure, a metal for forming an inner surface of a circular material 105 having a concave or H-shaped cross section having a cylindrical portion 104 on the outer periphery through a heat insulating material 103 at the tip of a drive shaft 102 rotatably mounted on a main shaft mechanism 101. The tail stock mechanism 107, which holds the mold 106 and faces the main shaft mechanism 101, is attached to the tip of a driven shaft 108 which is concentrically and rotatably mounted on the drive shaft 102, at the tip of the heat insulating material 109 as well as the circular shape. A mold heater for holding a mold 110 for molding the opposite inner surface of the material 105, and heating and maintaining the mold itself by, for example, a resistance heating heater on one or both of these molds 106, 110. In addition to the built-in 111, the circular material 105 that is sandwiched between the two molds 106 and 110 and rotates, similarly, the work heater 112 for heating and keeping the circular material 105 interferes with the processing roller 113. Outside the cylindrical part 10 4 of material 105 The heaters 111 and 112 are fixedly arranged in the space, so that hot spinning can be performed by using both the heaters 111 and 112.

The drive shaft 102 is rotated by a prime mover 114 such as a motor through the drive wheel 115, the transmission member 116 and the driven wheel 117, and the driven shaft 108 is integrally rotated together.

[0008]

[Problems to be solved by the device]

 However, in the method of heating by providing a heater inside the inner surface molding die as proposed in the conventional example 1 and the conventional example 2, the time required for heating the work material and each part of the work material are different. There is a problem in terms of temperature uniformity. That is, in the manufacturing process of the one-piece wheel, the process of spinning forming is generally performed after the forging process.Therefore, after finishing the forging process, the work material is set in the inner surface forming die and heated to a certain temperature.・ The temperature rises, but since the workpiece is only in partial contact with the mold, it takes a lot of time to raise the temperature of the workpiece and bring it to a uniform temperature. However, there is a problem that productivity is poor.

Further, there is a problem that the inner surface molding die in which the heater is installed becomes expensive, and the rearrangement and maintenance thereof become complicated. On the other hand, as proposed in Conventional Example 3, in the method of preheating the work piece offline and then setting it in the inner surface molding die, there is a problem in terms of dimensional accuracy because handing during setting is difficult. However, there is a problem in that the yield occurs and the yield decreases. In addition, there is a problem that temperature control is difficult due to indirect heating by the heater inside the mold.

In view of the above problems, the present invention heats and heats a work piece and an inner surface molding die uniformly by dielectric heating to heat and keep the work piece at a target temperature in a short time. , Aims to significantly improve productivity.

[0011]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a forming apparatus for forming a work wheel, which is formed by forging and is sandwiched by dies on both driving and driven shafts, by warm spinning to form a vehicle wheel. As a heating means for the mold and the work material, an induction heating device is arranged coaxially with both the driving and driven shafts for supporting the mold, and the dielectric heating device is movable. The induction heating device is equipped with a lubricant supply means to the work material and a water cooling means.

[0012]

[Action]

 According to the present invention, by using an induction heating device as a heating means for a work piece, the work piece set in the inner surface molding die can be uniformly heated and kept warm to a target temperature in a short time. It will be possible and productivity will be greatly improved, resulting in significant cost reduction.

When the induction heating device is provided with a lubricant supply means, the lubricant application process can be automated, uniformized, and the device can be made compact, and productivity and quality can be improved. If a water cooling unit is attached to the induction heating device, the temperature of the work piece in each pass can be controlled freely in a short time, which makes it possible to manufacture high quality forged wheels. The property is also improved.

[0014]

【Example】

 A preferred embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a horizontal type of the conventional spinning molding apparatus shown in FIG. 3, in which some of the publicly known parts are omitted and only essential parts are shown. In the vehicle wheel molding apparatus of the present invention, the components necessary for the spinning process, that is, the main shaft mechanism, the tail stock mechanism, the drive shaft, the driven shaft, and the inner surface molding die held on both shafts, and further, The basic configuration of the plurality of processing rollers and the like is the same as that of the spinning molding device that has been conventionally used, and thus the description thereof is omitted.

First, based on the schematic view of FIG. 1, a spinning process for forming a magnesium alloy wheel will be described. The material of the workpiece 1 is a magnesium alloy for forging (ZK60A). First, the work material 1 is forged and deburred, and then held at room temperature by the inner inner surface molding die 2 and the outer inner surface molding die 3 and driven by a drive motor (not shown). It is rotated at a constant speed. The inner surface molding dies 2 and 3 are heated in advance by an induction heating device 4 so as to reach a target temperature of 250 ° C. Next, the induction type heating device 4, which is coaxial with the drive and driven shafts 6 and 7 that supports the inner surface molding dies 2 and 3, is moved to the position indicated by the dashed line using the hydraulic cylinder 5. Then, the induction heating device 4 is input to raise the temperature of the workpiece 1 to the target temperature (250 + α) ° C. After the workpiece 1 reaches the target temperature, the induction heating device 4 is retracted to its original position. After that, the wheel rim is formed by performing a spinning process according to a predetermined time schedule. As the molding conditions at this time, for example, the processing temperature may be 250 ° C., the inner surface molding die rotation speed may be 200 rpm, and the pass speed may be 3, and the lubricant may be graphite-based. It should be noted that the setting of the heating conditions for the work material 1 can be initialized by a database using table values, the temperature of the work material 1 can be detected by a non-contact infrared thermometer, and the signal can be used to automatically control dynamically. it can. Further, by using the automatic control device, the heating time is shortened and excessive temperature rise is prevented.

In the apparatus of the above-mentioned embodiment, the induction heating device 4 is moved to the position of the workpiece 1, but the induction heating device 4 is fixed and the inner surface molding die of the spinning device is moved. It may be an expression. Also, since the inner surface molding dies 2 and 3 are preheated as described above, there is almost no need to reheat them due to their heat capacity.However, when handling large diameter and wide wheels these days, Since the number of times also increases, if necessary, reheating may be performed under the same conditions as described above.

By using an induction heating device as a heating means for the workpiece, for example, after setting the magnesium alloy wheel using a device similar to the conventional one, it takes about 120 seconds to raise the temperature to 250 ° C. However, with the device of the present invention, it is possible to raise the temperature in a short time of about 30 seconds, and the temperature difference between the various parts of the work piece is about 20 ° C at maximum even after the temperature rise. However, with the device of the present invention, it is made uniform at about 10 ° C. As described above, according to the present invention, it is possible to uniformly heat and heat the workpiece set in the inner surface molding die up to the target temperature in a short time, which greatly improves the productivity and greatly Cost reduction can be realized.

Next, a method of supplying the lubricant to the work material 1 and a method of cooling the work material 1 using the water cooling means will be described with reference to FIG. FIG. 2 is an enlarged cross-sectional explanatory view of the induction heating device 4, in which the body of the induction heating device 4 is provided with a lubricant supply means for the workpiece 1 and a water cooling means. A ring-shaped air spray nozzle 8 is shown as an example, and a fountain nozzle 9 is shown as an example of the latter.

First, the lubricant is supplied by using the air spray nozzle 8 to uniformly supply, for example, a graphite-based lubricant to the surface of the workpiece 1. The supply of the lubricant is performed before each pass of the spinning process, the induction heating device 4 is moved for that purpose, and the lubricant is supplied to a necessary portion. As a specific method, the lubricant is supplied while controlling the timing of the lubricant supply by interlocking the time setting of each pass and the control device of the hydraulic cylinder 5.

In addition to the above method, the lubricant may be supplied by dividing the air spray nozzle 8 for supplying the lubricant into several parts in the axial direction and controlling the zone. Further, as described above, there is a case where it is necessary to reheat the material 1 to be processed, in which case the supply of the lubricant and the reheating may be performed at a predetermined timing. As described above, by providing the induction heating device 4 with the lubricant supply means, the lubricant application process can be automated and uniformized, and the device can be made compact, thereby improving productivity and quality.

Next, the workpiece 1 is cooled by spraying water using the fountain nozzle 9. The workpiece 1 is cooled when it is desired to change the processing temperature for each pass, and the temperature can be easily controlled by changing the spray amount and time using the above method. . The specific operation of the cooling means is similar to that of the induction heating device 4. In this case, a specific example of the thermomechanical treatment method using the water cooling means is as follows. First, since the large pass is used for large deformation in the first pass, the processing temperature is controlled at 300 ° C, and the second pass and the third pass are the finishing process. By lowering the processing temperature to 180 ° C., it becomes possible to perform processing with a finer processed structure and higher dimensional accuracy. Here, the temperature control of the workpiece 1 can be automatically controlled as in the case of heating by using the non-contact infrared thermometer and linking it with a water cooling device.

On the other hand, in the case of the step of omitting the heat treatment, it is possible to perform water cooling and quenching by the water cooling means immediately after the finishing pass at a predetermined temperature, and then perform an aging treatment at 200 ° C. for about 24 hours. it can. In this way, by attaching water cooling means to the induction heating device, it is possible to control the temperature of each pass in a short time and freely, which makes it possible to manufacture high-quality forged wheels and improve productivity. Also improves.

[0023]

[Effect of device]

 According to the present invention, by using the induction heating device as the heating means for the work material, the work material can be uniformly heated and kept at the target temperature in a short time, and online heat treatment is possible. As a result, productivity can be greatly improved and a significant cost reduction can be realized. In addition, the hardware configuration of the processing equipment itself is simple and the workability when changing molds is greatly improved, making it easy to handle small lots and multiple products.

When the induction heating device is provided with a lubricant supply means, the lubricant application process can be automated, uniformized, and the device can be made compact, and productivity and quality can be improved. Further, when the induction heating device is provided with a water cooling means, the temperature of each pass can be freely controlled in a short time, so that a high quality forged wheel can be manufactured and productivity is improved. improves.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of an essential part showing an embodiment of the device of the present invention.

FIG. 2 is an enlarged sectional explanatory view showing an embodiment of the induction heating device of the device of the present invention.

FIG. 3 is a cross-sectional view of essential parts showing an example of a conventional spinning processing apparatus.

[Explanation of symbols]

 1 Workpiece material 2 Inner surface molding die 3 Inner surface molding die 4 Induction heating device 5 Hydraulic cylinder 6 Drive shaft 7 Driven shaft 8 Air spray nozzle 9 Fountain nozzle

Claims (2)

[Scope of utility model registration request] 1. A molding apparatus for forming a vehicle wheel by performing warm spinning processing on a material which is formed by forging and is sandwiched by dies on both driving and driven shafts.
An apparatus for molding a vehicle wheel, characterized in that an induction heating device is provided as a heating means for the die and the work material coaxially with both drive and driven shafts for supporting the die. 2. The vehicle wheel molding apparatus according to claim 1, wherein the dielectric heating device is movable, and the induction heating device is provided with a means for supplying a lubricant to the material to be processed and a water cooling means.