JPH0475105B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for forming a ring-shaped product and an apparatus therefor. The present invention relates to a method and apparatus for forming a ring-shaped product such as a wheel rim for a vehicle having a wide and inclined surface, such as a bus or a passenger car.

[Prior art] Generally, this type of ring-shaped product is produced by pressing,
It is formed by a method called spinning processing or ring roll processing. Among these, in the ring roll processing, a ring-shaped material is generally interposed between a driving roll and a pressure roll that face each other, and while the inner peripheral surface of the ring-shaped material is rotated by the driving roll, the pressure roll is This method is known as a method of stretch-forming while asymptotically moving the material toward the drive roll and bringing it into contact with the outer circumferential surface of the material. In this case, in ring roll processing, the thinner the wall thickness of the ring-shaped material, that is, the larger the diameter of the ring-shaped material, the faster the forming speed, and the forming speed becomes faster to form the ring-shaped material with good roundness and accuracy to the target diameter. It is said that this is difficult. Conventional techniques include a method in which after ring roll processing, press forming is performed to achieve the specified size and shape accuracy, and then ring roll processing is performed again to form the product (see Japanese Patent Application Laid-Open No. 60-6231), and the position of the reduction roll is detected. A method of controlling the roll gap, that is, the wall thickness of the wheel rim (see JP-A-56-62637 and JP-A-58-90339), or
A method in which the pressing force of the reduction roll is gradually reduced as the wheel rim diameter increases, and at the same time, just before the end of forming, the pressing force is applied to allow slight stretch forming (Japanese Patent Laid-Open No. 62-263839 ) etc. are known.

[Problems to be Solved by the Invention] However, in the method of combining ring roll processing and press processing, the dimensions can be determined by the press processing, so when ring rolling, the difference in the outer diameter of the widthwise end of the wheel rim is Although this method is allowed to some extent and there is no need for fine adjustment of the roll gap, it has the disadvantage that it is not suitable for mass production because it increases the number of processing steps and requires a lot of labor and time. In the case where the product diameter is controlled by detecting the position of the reduction roll at the final stage of forming, the method is to control the roll gap, so even when the pressure of the pressure roll is stopped, the ring-shaped material remains elastically deformed. The material is stretched and formed due to the elastic deformation of the machine, which occurs because the rigidity of the machine itself has a finite value, and the roll gap essentially changes, so control in micrometer units is required, making control extremely difficult. There's a problem. Also,
The method of reducing the pressurizing force in stages and forming with a slight pressurizing force just before the end of forming was developed by the applicant earlier, and was designed to improve roundness and dimensional accuracy. Even with this method, it was difficult to process the target ring-shaped product within the tolerance range (product diameter ±0.35 mm) due to fluctuations in pressurizing force (hydraulic pressure), uneven material strength, etc.

This invention was made in view of the above circumstances,
The purpose of this is to make it possible to obtain the target roundness and dimensional accuracy of the product even when the weight of the ring-shaped material is uneven, or the strength or hardness of the material being processed differs. The present invention aims to provide a method for molding a ring-shaped product and an apparatus therefor.

[Means for Solving the Problem] In order to achieve the above object, the present invention has the following features:
2, one of the opposing pressure rolls moves asymptotically toward the other mandrel roll.
When forming a ring-shaped product by stretch-molding the ring-shaped material by interposing the ring-shaped material between two rolls, the diameters of both ends in the width direction of the ring-shaped material being formed are separately measured, and the measured value is A signal of the compared value is sent to the mandrel roll operating unit to control the inclination of the mandrel roll so that the left and right diameters are the same, and as the diameter of the ring-shaped material increases, the pressure roll Provided is a method for molding a ring-shaped product, characterized in that the ring-shaped product is molded while controlling the moving speed so that it gradually decreases in accordance with a preset processing speed reference value, and 2. A ring-shaped product forming device that stretches and forms a ring-shaped material by interposing a ring-shaped material between two opposing rolls in which one pressure roll moves asymptotically toward the other mandrel roll. A pressure roll control unit that controls the moving speed of the pressure roll, a mandrel roll operation unit that adjusts the inclination of the mandrel roll, and a diameter dimension of both ends in the width direction of the ring material being formed are separately controlled. a measuring means for measuring;
a control unit having a comparison calculation unit that receives a signal from the measurement means and compares the measured value; and a speed control calculation unit that compares the signal input from at least one of the measurement means with a preset machining speed reference value; A comparison signal from the control section is transmitted to the mandrel roll operation section to adjust the inclination of the mandrel roll, and a speed control signal from the control section is transmitted to the pressure roll control section to apply pressure. It is an object of the present invention to provide a molding device for a ring-shaped product, which is characterized in that the moving speed of the roll is controlled to gradually become slower as the diameter of the ring material increases.

In this invention, if the pressure roll whose moving speed is adjusted and the mandrel roll whose inclination is adjusted face each other and one moves asymptotically toward the other, they may move relative to each other in the vertical or horizontal direction. It's okay.

The pressure roll control unit may be of any type as long as it controls the moving speed of the pressure roll, but it is preferable that it has a structure that converts the rotation of a servo motor into linear movement via a ball screw. good. In this case, the pressure roll control section may be provided separately from the pressure operation section of the pressure roll, or may be structured to be used also as the pressure operation section.

Further, the mandrel roll operating unit may be any type as long as it adjusts the inclination of the mandrel roll. For example, it may be structured to move one example of the roll, and one side of the roll may be directly moved by a cylinder device. Alternatively, the movement from the cylinder device can be performed by any arbitrary means, such as using the "lever principle" to adjust the position of the roll.

On the other hand, the measuring means may be any device such as a photo sensor or a proximity switch that detects the outer diameter of the ring-shaped material, but preferably measures the outer diameter of the ring-shaped material during molding. It is preferable that the detection object follow and abut against the ring-shaped material.

In addition, the control section has a comparison calculation function that receives signals from the measuring means and compares measured values, and a signal input from one measuring means (device) or two.
Any device may be used as long as it has a speed control calculation function that compares the average value of signals input from two measurement devices with a preset machining speed reference value, but preferably it has a comparison calculation section and a speed control calculation function. It is better to use a microcomputer that embodies the In this case, the speed control calculation involves, for example, comparing the processing speed standard characteristic curve determined in advance through experiments with the temporal change in the diameter of the ring-shaped material, and adjusting the moving speed of the processing roll so that the two match. It can be a control method.

[Effect] The above technical means works as follows.

While the ring-shaped material interposed between the opposing pressure roll and mandrel roll is stretched and rotated, the measuring means detects the outer diameter dimension of both ends of the ring-shaped material in the width direction. When the difference between the two values is out of the permissible range, a signal is sent to the mandrel roll operating section, which adjusts the inclination of the mandrel roll and the parallelism of both rolls, thereby controlling the ring-shaped material. The outer diameter of the ends in the width direction is formed uniformly. In addition, as the diameter of the ring-shaped material increases, the moving speed of the pressure roll is controlled in accordance with a preset processing speed reference value, which can reduce the unevenness of the weight of the ring-shaped material, the strength of the material being processed, and the like. A ring-shaped product having the target roundness and dimensional accuracy can be obtained regardless of the difference in hardness.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

◎First Embodiment FIG. 1 is a front view showing a first embodiment of a molding apparatus for a ring-shaped product according to the present invention, and FIG. 2 is a side view thereof.

The molding apparatus of the present invention includes a servo motor 16 for lifting and controlling the pressure roll mounted on a cylinder bracket 14 projecting from the upper part of a frame 12 erected on a base 10, and a servo motor 16 for lifting and controlling the pressure roll.
A pressure roll 18 with a rotating function that is supported so as to be able to rise and fall via a ball screw 16a on the driving side of the roller, and a bearing section 22 between the frame 12 and the lower end of a bearing arm 20 that is pivotally supported on the cylinder bracket 14. 22
A ring-shaped material is interposed between the mandrel roll 24, which is rotatably supported by the bearing arm 20, and the mandrel roll 24, which faces the pressure roll 18 in the vertical direction. A measuring means 28 consisting of two outer diameter measuring devices 26, 26 that follow and abut the left and right lower ends of the material A to measure the outer diameter dimension of the material A;
Upon receiving the signal from the measuring means 28, the measured values are compared and calculated, and the signal from one outer diameter measuring device 26 or the average value of the signals from the two outer diameter measuring devices 26, 26 and a preset machining speed standard are calculated. a control unit 30 that compares the values with the values; a mandrel roll operating unit 32 that receives signals from the control unit 30 and controls the inclination of the mandrel roll 24; and a drive motor 34 that transmits rotational drive to the pressure roll 18.
The main part consists of.

The pressure roll 18 is disposed in a pressure roll case 13 attached to the nut of the ball screw 16a of the servo motor 16, and is controlled by a servo motor in response to a signal from the control unit 30. The rotation of the motor 16 is converted into a vertical motion via a ball screw 16a, so that the speed of vertical movement is controlled. Further, the output side of a drive motor 34 is connected to a pressure roll shaft 15 that controls the rotation of this pressure roll 18 via a universal joint 17 and a reduction gear 19.

On the other hand, as shown in FIGS. 3 and 4, the mandrel roll 24 has a bearing portion 2 which is rotatably pivotally connected to the frame 12 and the bearing arm 20.
Mandrel roll shaft 24 supported by 2, 22
It is attached to a. In this case, the bearing portion 22 is
Frame 12 or bearing arm 2 with pin 21
A tapered sleeve 27 is rotatably housed in a bearing casing 23 via a bearing 25, and this tapered sleeve 27
A tapered portion 24b formed at the end of the mandrel roll shaft 24a is fitted inside. Further, the mandrel roll shaft 24a is connected to the tapered sleeve 27 on the frame 12 side by a presser plate 29 and fixing bolts 29a and 29b, and is removably fitted to the tapered sleeve 27 on the bearing arm 20 side. There is. It goes without saying that the mandrel roll 24 may be made integrally with the mandrel roll shaft 24a.

The bearing arm 20 is attached to the cylinder bracket 1
It is vertically rotatably supported by a fulcrum shaft 36 which is pivotally connected to the frame 12, and a pin 33 is connected to a movable bearing cylinder bracket 31 erected on the upper end surface of the frame 12 at its upper end. A piston rod 38a of a hydraulic movable bearing cylinder 38 that is swingably supported is connected via a joint pin 38b, and the extension and contraction of the movable bearing cylinder 38 moves the bearing arm 20 to the use position during molding. It is designed to be opened and closed in a non-use position when the ring-shaped material A is removed. Also, bearing arm 2
A mandrel roll shaft driving motor 35 is attached to the lower end of the mandrel roll shaft 24a via a ratchet mechanism 37 and is detachably connected to the mandrel roll shaft 24a.

On the other hand, the mandrel roll operation section 32 controls a lift arm 40 that projects upward from an eccentric section (not shown) formed coaxially with the fulcrum shaft 36, and the rotation of this lift arm 40. It is composed of a hydraulic power cylinder 42. In this case, the power cylinder 42 is connected to the frame 1.
It is swingably supported with a pin 43 on a power cylinder bracket 41 erected on the upper end surface of 2, and a piston rod 42a is attached to a joint pin 42.
It is connected to the upper end of the lift arm 40 via b. Therefore, when the lift arm 40 rotates due to the expansion and contraction operation of the power cylinder 42, the bearing arm 20 can move in the vertical direction due to the "lever principle" between the lift arm 40 and the eccentric portion. There is. Here, lift arm 4
If the distance between the fulcrum shaft 36 of the power cylinder 42 and the pivot part of the power cylinder 42 is 50 mm, and the eccentricity of the eccentric part is 1 mm, then the piston rod 42a of the power cylinder 42
moves 50mm, while the bearing arm 20 moves 1mm.
The mandrel roll 24 can be moved to adjust its position. In this case, the power cylinder 42 has a mechanism (not shown) that converts the rotation of the motor 44 into linear motion, and uses a trapezoidal screw (not shown) to ensure accurate expansion and contraction movement.

A pair of side support rolls 50, 50 are arranged on the sides of the frame 12 on both sides of the mandrel roll 24 so as to be able to follow changes in diameter to prevent the ring-shaped material A from swinging in the horizontal and vertical directions. It is set up.

The measuring means 28 includes a measuring roll 26a which is interposed between the pressure roll 18 and the mandrel roll 24 and comes into contact with measuring positions on both sides of the lower end of the ring-shaped material A to be stretched and formed, and the measuring roll 26a.
A pair of brackets 26 that rotatably support 6a
b, 26b, and a vertically movable cylinder 26d that supports the support plate 26c in a vertically movable manner.
By applying a predetermined air pressure to the vertically moving cylinder 26d, the measuring roll 26a can follow the vertical displacement of the ring-shaped material A due to stretching. The data of the measuring means 28 configured in this way is compared and calculated by the control section 30, which is a control means.
The signal is electrically transmitted to the motor 44 of the power cylinder 42 of the mandrel roll operating section 32.

On the other hand, the control section 30 includes a comparison calculation section that receives signals from both the outer diameter measuring devices 26 and 26 of the measuring means 28 and compares and calculates the measured values, and a signal from one of the outer diameter measuring devices 26 or the two outer diameter measuring devices 26 of the measuring means 28. Diameter measuring device 2
It is formed by a microcomputer that has a speed control calculation unit that compares the average value of the signals input from 6 and 26 with a preset machining speed reference value, and the signal from the comparison calculation unit is used for mandrel roll operation. 32, and a signal from the speed control calculation section is sent to the servo motor 16.

In order to form a ring-shaped product using the apparatus configured as described above, first, the movable bearing cylinder 38 is contracted to open the bearing arm 20, and the ring-shaped material A is inserted into the mandrel roll 24. After that, the moving bearing cylinder 38 is extended and the bearing arm 20 is closed. Next, when the drive motor 34 is driven to drive the pressure roll 18 and at the same time the pressure roll operating servo motor 16 is rotated, the pressure roll 18 is lowered via the ball screw 16a (no load (before processing starts)). )15~30mm/sec, 1 at the start of machining
~2 mm/sec}, and comes into contact with the outer peripheral surface of the ring-shaped material A, and rotates and stretches the ring-shaped material A between it and the mandrel roll 24. At this time, at the start of driving, the mandrel roll shaft drive motor 35 is driven to move the mandrel roll 24 through the ratchet mechanism 37.
By auxiliary driving of the engine, operation at startup becomes smooth. In this case, when the rotational speed of the mandrel roll 24 due to the rotation of the pressure roll 18 becomes faster than the rotational speed of the mandrel shaft drive motor 35, the ratchet mechanism 37 causes the mandrel shaft drive motor 35 to idle without transmitting the power. do. Further, the mandrel roll shaft drive motor 35 is also stopped after a certain period of time by a timer (not shown).

While the material A is stretch-molded by the rotation of the pressure roll 18 and the mandrel roll 24, the left and right outer diameter dimensions of the material A are measured by the measuring means 28, and the measured values are subjected to a comparison calculation by the control means 30. If there is a displacement difference between the left and right sides that exceeds the tolerance, the signal is sent to the motor 44 of the power cylinder 42.
The inclination of the mandrel roll 24 is adjusted via the bearing arm 20 by the operation of the power cylinder 42. For example, in FIG. 2, when the outer diameter of the left side is large, the left side is rolled down more, so a signal is sent to increase the dimension between the left pressure roll 18 and the mandrel roll 24, that is, an action to lower the bearing arm 20. is commanded, and the power cylinder 42 performs a contraction operation. On the other hand, when the outer diameter of the left side is small, a signal is issued to narrow the dimension between the left side pressure roll 18 and the mandrel roll 24, that is, an operation to raise the bearing arm 20 is commanded, and the power cylinder 42 is extended. In this case, when the movable bearing arm 20 moves downward, the piston rod 38a of the movable bearing cylinder 38 is moved by hydraulic pressure.
is pressed toward the bearing arm 20 side. Conversely, when the bearing arm 20 moves upward, the pressure from the bearing arm 20 overcomes the hydraulic pressure of the moving bearing cylinder, so the piston rod 38a in the moving bearing cylinder 38 retracts, and eventually, The pressurizing force is absorbed within the entire hydraulic system. Therefore,
The movement of the bearing arm 20 and the mandrel roll 24 is absorbed by the movement of the piston rod 38a of the movable bearing cylinder 38 and the rotation angle of the movable bearing cylinder 38, which is pivotally connected by the pin 33. It turns out.

Further, the control section 30 receives signals from the two outer diameter measuring devices 26 and 26 of the measuring means 28, and compares one of the signals or the average value of the two signals with a preset machining speed reference value. When the diameter of the ring-shaped material A increases, a signal is sent to the pressure roll control servo motor 16 to slow down the rotation of the servo motor 16 and the moving speed of the pressure roll 18. Then, the ring-shaped material A is formed. In this case, the processing speed reference value is obtained based on data obtained in advance through experiments, and for example, the processing speed standard value is obtained based on data obtained in advance through experiments.
(JIS5154 aluminum alloy) Nominal diameter 406.4mm
(outer diameter 442.4 mm), as shown in Figure 5, the processing speed standard characteristic curve and the outer diameter measuring device 2
The moving speed of the pressure roll 18 is controlled so that the actual machining speed curve obtained from the signals from the pressure rolls 6 and 26 (one of the signals or the average value of both) matches the actual machining speed curve. in particular,
Movement speed control starts when 90 to 95% of the target diameter has passed, and the speed is changed just before the end of molding.
0.2 to 0.1 mm/sec (4/10000 to 2/10000 with respect to the diameter of ring-shaped material A). Note that since the moving speed of the pressure roll 18 is affected by the diameter, wall thickness, etc. of the product, it is necessary to prepare in advance a characteristic curve that is a processing speed reference value for each product.

In order to form the ring-shaped material A as described above, the ring-shaped material A is divided into multiple stages to form the ring-shaped product, and the moving speed of the pressure roll 18 is controlled in the final stage to achieve the target accuracy. Although the dimensions are obtained, preferably by controlling the moving speed of the pressure roll 18 at each stage, it becomes possible to obtain a product with even better dimensional accuracy.
For example, outer diameter: 192mm, wall thickness: 11.5mm, width: 254mm
Nominal diameter of ring-shaped material A: 406.4 mm, width: 203.2
To make a mm product, mold it as follows.

1st stage: Molding to an outer diameter of approximately 290mm.

Second stage: Molding to an outer diameter of approximately 380mm.

Third stage (final stage): Finish to a nominal diameter of 406.4mm.

◎Second Embodiment FIGS. 6 and 7 are a plan view and a front view of a second embodiment of the molding apparatus of the present invention, in which a pressure roll and a mandrel roll face each other in the horizontal direction, and the mandrel roll This is a case where the slope of the image can be adjusted. That is, the pressure roll case 13 is attached to the ball screw 16a of the pressure roll control servo motor 16, which is attached to the cylinder bracket 14 that projects upward from the side of the frame 12 that is erected on the base 10. A mandrel roll 24 is formed between the free end of a bearing arm 20 pivotally supported by the cylinder bracket 14 and the frame 12 through bearings 22, 22. The ring-shaped material A is supported rotatably in the horizontal direction and is supported in a tilt-adjustable manner by a bearing arm 20, and is interposed between the pressure roll 18 and the mandrel roll 24 that face each other in the horizontal direction. , this is the case when stretching is performed. In this case, since it is necessary to support the ring-shaped material A in a horizontal state, a pair of support rolls 52, 52 for supporting the lower end of the material A are provided at the lower part of the frame 12 on the measuring means 28 side, and a mandrel roll 24 The side support rolls 50, 50 are disposed at symmetrical positions in a direction orthogonal to the support rolls 52, 52. In this case,
The support roll 52 and the side support rolls 50 are formed to be movable and adjustable in accordance with the shape and dimensions of the ring-shaped material A.

The other parts of the second embodiment are basically the same as those of the first embodiment, so the same parts are given the same reference numerals and the explanation thereof will be omitted.

[Effects of the Invention] Since the present invention is configured as described above, the following effects can be obtained.

(1) Since the inclination of the mandrel roll is adjusted according to the difference in the outer diameter of both ends of the ring-shaped material in the width direction, the left and right diameters of the ring-shaped product can be formed to be the same.

(2) The processing speed is controlled so that it gradually slows down as the diameter of the ring-shaped material increases in accordance with the optimum setting standard value for the weight, strength, hardness, and target diameter of the ring-shaped material to be formed. Even for items with uneven weight, strength, etc., the errors can be absorbed, and ring-shaped products with good roundness and dimensional accuracy can be molded.

[Brief explanation of drawings]

Fig. 1 is a front view showing a first embodiment of a ring-shaped product forming apparatus according to the present invention, Fig. 2 is a side view thereof, and Fig. 3 is a main part showing a state in which a mandrel roll is attached in the first embodiment. 4 is a perspective view showing the main parts of the mandrel roll, FIG. 5 is a characteristic curve diagram showing the relationship between the diameter of the ring-shaped material and processing time in this invention, and FIG. 6 is a second diagram of the present invention. A plan view showing the embodiment, and FIG. 7 is a front view thereof. Description of symbols, 16... Servo motor for pressure roll control, 16a... Ball screw, 18... Pressure roll, 20... Bearing arm, 21... Pin, 22...
... Bearing part, 24 ... Mandrel roll, 26 ...
Outer diameter measuring device, 28... Measuring means, 30... Control section, 32... Mandrel roll operating section, 38...
Cylinder for moving bearing, 39... Cylinder for position adjustment, 40... Lift arm, 42... Power cylinder.

Claims (1)

[Claims] 1. One pressure roll of the opposing rolls moves asymptotically toward the other mandrel roll. 2.
When forming a ring-shaped product by stretch-molding the ring-shaped material by interposing the ring-shaped material between two rolls, the diameters of both ends in the width direction of the ring-shaped material being formed are separately measured, and the measured value is A signal of the compared value is sent to the mandrel roll operating unit to control the inclination of the mandrel roll so that the left and right diameters are the same, and as the diameter of the ring-shaped material increases, the pressure roll A method for molding a ring-shaped product, characterized in that the ring-shaped product is molded while controlling the moving speed so that it gradually slows down in accordance with a preset processing speed reference value. 2 One pressure roll of the opposing rolls moves asymptotically towards the other mandrel roll2
In a ring-shaped product forming apparatus that stretches and forms a ring-shaped material by interposing the ring-shaped material between two rolls, the pressure roll control section controls the moving speed of the pressure roll and adjusts the inclination of the mandrel roll. a mandrel roll operation section for performing the operation, a measuring means for separately measuring the diameter dimension of both ends in the width direction of the ring material being formed, a comparison calculation section for receiving a signal from the measuring means and comparing the measured values, and at least one of the measuring means. a control section having a speed control calculation section that compares the signal input from the measuring means with a preset processing speed reference value, and transmits the comparison signal from the control section to the mandrel roll operation section. In addition to adjusting the inclination of the mandrel roll, a speed control signal from the control section is transmitted to the pressure roll control section to control the moving speed of the pressure roll so that it gradually becomes slower as the diameter of the ring material increases. A molding device for ring-shaped products, which is characterized by: