KR100289345B1 - Machining rolls used for spinning and copper machining - Google Patents

Abstract

The present invention provides a spinning processing method and a processing roll for use in the spinning process, in which spinning can be performed without annealing heat treatment by suppressing work hardening of the work piece when spinning is performed. And forming the disk-shaped workpiece W fixed to the end surface of the mandrel according to the outer circumferential surface of the mandrel 7, and pressing the workpiece W on the outer circumferential surface of the mandrel. In the spinning machining method, a compressive stress in the radially inward direction is applied to a disk-shaped workpiece W, and the workpiece W is molded into a cylindrical shape, and the workpiece formed into the cylindrical shape is subjected to the mandrel ( 7) is a spinning process for pressing on the outer circumferential surface, and the processing roll 27 used in the processing method is a shape in which the processing roll 27 is opened to the outer circumferential surface of the roll 27 in the axial and radial directions. 을 form a curved surface, , It is made to form a working surface (29) the cross-sectional shape forming a circular arc.

Description

Processing rolls used for spinning and copper processing

The present invention relates to a machining roll for use in a spinning machining method and a copper machining method, and more particularly, even when a workpiece is a material that is likely to cause work hardening, spinning can be performed without annealing. It relates to the spinning roll processing method and the processing roll used for the copper processing method.

Conventionally, for example, internal tooth gears are processed by spinning. Conventionally, a disk-shaped workpiece is fixed by tail stock to a tip end portion of a mandrel on which a gear to be transferred to the outer peripheral surface of the tip side is pressed, and while rotating the mandrel, the work piece is attached to the outer peripheral surface of the mandrel by a working roll. The inner toothed gear is processed by pressing to form a cylindrical or cup shape and pressing the workpiece against the outer circumferential surface of the mandrel.

As described above, when the inner tooth gear is processed by spinning, when the material of the workpiece is, for example, a high carbon steel, the disk-shaped workpiece may be formed in a cylindrical or cup shape. At this time, it is necessary to perform molding processing several times. At this time, when the forming process is performed, the work piece causes work hardening. Therefore, in order to alleviate this work hardening, it is necessary to perform annealing between the molding work processes.

If the annealing is not performed, there is a problem that deformation is accumulated and breakage occurs in the product.

Therefore, conventionally, annealing is required and there is a problem that the production efficiency is poor.

1 is an explanatory view schematically showing a processing apparatus for implementing the processing method of the present invention;

FIG. 2 is an explanatory view seen from line II-II of FIG. 1;

3 is a shape explanatory diagram of a processing roll used in the method of the present invention;

4 is an operation explanatory diagram showing a machining step;

5 is an explanatory diagram showing the relationship between the radius of curvature of the machined surface in the machining roll, the plate thickness increase rate, and the feed rate;

Fig. 6 is an explanatory diagram of a portion where a crack tends to occur in the workpiece and the cause thereof.

<Explanation of symbols for main parts of drawing>

7: mandrel 11: tail stock

23: machining roll 27: machining roll

29: machining surface

The present invention has been made in the light of the above-described conventional problems, and the invention according to claim 1 forms a cylindrical work piece fixed to the end surface of the mandrel in a cylindrical shape along the outer circumferential surface of the mandrel, and at the same time, the mandrel In a spinning machining method for pressing a workpiece on an outer circumferential surface thereof, a disk-shaped workpiece is subjected to a radial stress in a radially inward direction to be molded into a cylindrical shape, and the cylindrically shaped workpiece is formed into a cylindrical shape. Spinning is a method of pressing on the outer circumferential surface.

In the invention according to claim 2, in the invention according to claim 1, the outer peripheral surface of a working roll for processing a workpiece when applying a compressive stress in a radially inward direction to a disk-shaped workpiece is formed into a cylindrical shape. The processing surface formed in the is a curved surface having a radius of 15 mm to 20 mm, and the feeding speed of the processing roll to the workpiece is 15 to 22 mm / min.

The invention according to claim 3 is a processing roll for forming a cylindrical work piece fixed to a front end surface of a mandrel into a cylindrical shape along the outer circumferential surface of the mandrel, wherein the outer circumferential surface of the roll has an axial direction and spinning It forms by forming the curved surface of the shape which opened in the direction, and the cross section shape makes the circular arc shape.

Invention concerning Claim 4 is a process roll whose radius of the arcuate part of a process surface is 15 mm-20 mm in invention of Claim 3.

<Embodiment of the invention>

First of all, in order to facilitate understanding, the overall configuration of the apparatus provided in the practice of the present invention is outlined.

Referring to Fig. 1, a headstock 3 is provided at one side of the bed 1, and the headstock 3 is rotatably supported horizontally by a spindle 5, which is rotated by a built-in servo motor or the like. The main shaft 5 is attached with a mandrel 7 having a gear 7T to be transferred to the outer peripheral surface of the tip side.

A support 9 is provided on the other side of the bed 1, and the support 9 is provided with a tail stock 11 provided to face the mandrel 7 in the axial direction (left and right in FIG. 1, In the following, the axial direction is attached to a fluid pressure cylinder 13 operating in a direction parallel to the axis of the mandrel 7). The tail stock 11 serves to compress and fix the disk-shaped workpiece W on the distal end surface of the mandrel 7, which is arranged coaxially with the mandrel 7 and has an appropriate intermediate position in the longitudinal direction. Is rotatably supported and movable relative to the intermediate support member 15 installed on the bed 1 so as to be adjustable in position.

The work piece W press-fixed and fixed to the distal end of the mandrel 7 by the tail stock 11 is referred to as a cylindrical shape including a cup shape or a cylindrical shape (hereinafter also referred to as cup shape) along the outer circumferential surface of the mandrel 7. And a roll unit 17 for pressing the workpiece W into the gear 7T of the mandrel 7 is provided.

The roll unit 17 is axially movable on the bed 1 between the mandrel 7 and the intermediate support member 15. The roll unit 17 is reciprocated in the axial direction by the driving of the servo motor, and the through stock 19 of the penetrating material is formed at the position corresponding to the tail stock 11. .

In addition, the roll unit 17 is provided with a plurality of sliders 21 which are reciprocally radially reciprocated about the shaft center 19P of the through hole 19 at equal intervals, and each of the sliders 21 has a processing roll. 23 are rotatably attached and detachable. Each said slider 21 is provided so that it may reciprocate synchronously by the drive of the appropriate actuator 25, such as each servo motor etc. which were attached to the roll unit 17. As shown in FIG.

In the above configuration, as shown in FIG. 1, the work piece W is pressurized and fixed to the tip end of the mandrel 7 by the tail stock 11, and then from the shaft center 19P to each processing roll 23. FIG. By appropriately adjusting the distance, rotating the mandrel 7 properly, and moving the roll unit 17 to the left in FIG. 1, the workpiece W on the disc is made to conform to the outer circumferential surface of the mandrel 7. It is molded into a cylindrical shape. The work piece W is pressurized and pressed very strongly by the gear 7T of the mandrel 7 by the respective working rolls 23, so that the gear 7T is transferred to the inner circumferential surface of the cylindrical work piece so as to be internally pressed. Spinning of the gear is performed.

By the way, as mentioned above, when shape | molding the disk-shaped workpiece | work W in cylindrical shape along the outer peripheral surface of the mandrel 7, it is not possible to carry out molding processing in one process, and also Since the outer circumferential surface is subjected to an ironing action by the working roll 23, for example, work hardening is likely to occur when the workpiece W is a high carbon steel. Therefore, it is necessary to perform shaping | molding as mentioned above, performing annealing on the workpiece | work W, and it is inefficient.

Here, in this example, as shown in FIG. 3, the axial direction (the left direction in FIG. 3) of the said processing roll 27 is opened to the outer peripheral surface of the processing roll 27, and the radial outer side of the processing roll 27 is carried out. The compressive stress in the radially inward direction on the workpiece W by the working roll 27 which forms the curved surface of the shape which opened in the direction, and formed the processing surface 29 which makes the cross section circular arc shape. After the forming process is performed in a cup shape or a cylindrical shape, and the work piece W is pressed with force against the outer circumferential surface of the mandrel 7, the heat treatment can be omitted as described above.

That is, according to this example, as shown in FIG. 4 (1), after press-fixing the disk-shaped workpiece W to the distal end of the mandrel 7, the mandrel 7 is rotated. , The working surface 29 in the plurality of working rolls 27 is brought into contact with the outer circumferential surface of the work piece W, and the working rolls 27 are gradually moved in the radially inward direction (direction toward the shaft center 19P). In other words, the workpiece W is subjected to a compressive stress in response to a pressing force in the radially inward direction. Then, if the movement in the radially inward direction of the plurality of processing rolls 7 gradually proceeds, as shown in Fig. 4 (2), the workpiece W has a curved surface, so that the work piece W has a mandrel. The mold is processed so as to be directed in the direction along the outer circumferential surface of (7), and is molded into a cylindrical shape (compression step).

As described above, when the workpiece W is molded into a cup or a cylindrical shape, the workpiece W is molded while being compressed in the radially inward direction, so that the deformation of the workpiece W is in a reduced direction, The thickness of the piece W tends to increase and become thick.

As described above, after compressing the workpiece W in the radially inward direction to form a cup or a cylindrical shape, the working roll 27 is replaced with a cylindrical working roll 23 or the working roll 27. With the outer peripheral edge 29A forming an appropriate curved surface of Fig. 4 (3), the machining roll is placed so that the inner peripheral surface of the workpiece W formed into a cylindrical shape contacts the outer peripheral surface of the mandrel 7. It moves to the axial direction and press-forms, pressing to the workpiece | work W (drawing process).

Then, after the front surface of the inner circumferential surface of the work piece W comes into contact with the outer circumferential surface of the mandrel 7, the mandrel 7 is rotated as shown in Fig. 4 (4), and the work piece is driven by the processing roll. As shown in Fig. 4 (5), the gear 7T formed on the outer circumferential surface of the mandrel 7 is subjected to a pressing process by axially moving (W) to the outer circumferential surface of the mandrel 7 forcibly. The material flows between the teeth in the tooth, the gear 7 is transferred to the inner circumferential surface of the cylindrical work piece W, and spinning processing of the inner tooth gear is performed (ironing process).

When performing the pressing work of the workpiece | work W as mentioned above, the workpiece | work W becomes a form to be pulled, and the tensile stress acts on the workpiece | work W, and there exists a tendency for thickness to become thin.

In other words, in the present example, the disk-shaped work piece W is formed into a tubular shape in which the compressive stress in the radially inner direction is increased to increase the thickness, and then the ironing action is applied to the work piece W. Since the (W) is pressed into the mandrel 7, the work piece W is formed to be elongated and the tensile stress acts. Therefore, since the workpiece W is formed into a cylindrical shape in the direction in which the deformation is reduced by the compressive stress and then performs a stamping step in the direction in which the deformation is increased by the tensile stress, the molding limit can be increased. For example, compared to the case of spinning only by providing tensile stress, work hardening of the workpiece W can be suppressed, and spinning can be performed without annealing as in the prior art, thereby improving productivity. have.

By the way, when compressing the workpiece | work W in the radially inner direction as mentioned above, and shape | molding into cup shape or a cylindrical shape, the radius R of the circular arc part of the process surface 29 in the process roll 27 is carried out. And it is necessary to set the feed speed of the processing roll 27 with respect to the workpiece | work W to an appropriate range.

That is, when the radius R of the said processing surface 29 is small, when the workpiece W is to be shape-molded by the pressurization F of the processing roll 27, the workpiece W is Because of this rigid material, the fluidity of the metal is poor, and the work piece W is formed into a tubular shape as shown in Fig. 6 (2) without the smooth movement of the mandrel 7 in the direction along the axis of the mandrel. The increase in thickness of the portion WP close to the bottom of the processed workpiece W tends to be excessive, and the plate thickness increase rate at which the plate thickness of the workpiece W increases increases. When the plate thickness increase rate becomes large, there exists a tendency for strong compression to generate | occur | produce inside this part WP, and the crack CR tends to generate | occur | produce on the inner peripheral surface of this part WP. Therefore, it is not very preferable to make the radius R of the process surface 29 in the process roll 27 too small.

In addition, when the radius R of the process surface 29 in the said process roll 27 is large, when it tries to shape | mold the workpiece | work W to cylindrical shape, the direction along the axial center of the mandrel 7 Since the deformation of the workpiece W easily occurs, and the rate of increase in plate thickness is small, there is no problem of cracking. However, the compressive stress in the radially inward direction cannot be imparted to the workpiece W, and Since the increase rate of sheet thickness is small, it is unpreferable for raising the shaping | molding limit at the time of stamping of the next process.

Here, the relationship between the radius R of the curved surface of the arc surface of the process surface 29 in the process roll 27, and the feed rate of the process roll 27 with respect to the workpiece | work W was experimentally calculated | required, FIG. The result as shown to was obtained.

In FIG. 5, the curve A is a case where the radius R of the curved surface of the process surface 29 in the process roll 27 is 15 mm. When the disk-shaped workpiece W is compressed in the radially inward direction by the working roll, the sheet thickness increase rate of the portion WP adjacent to the bottom of the cylindrically shaped workpiece W is increased by the roller. As the feed speed increases, the thickness increases, and the plate thickness increase rate is about 20% at 15 mm / min, and the plate thickness increase rate is about 30% at 25 mm / min. Here, when the plate thickness increase rate is 30% or more, cracks are likely to occur in the thickness increase portion of the work piece W, so the plate thickness increase rate needs to be suppressed to 30% or less.

Curve B shows the case where the radius R of the curved surface of the processing surface 29 in the processing roll 27 is 20 mm. In this case, since the rate of increase of the plate thickness becomes maximum at about 15% near the feed rate of 15 mm / min, it is preferable to set the feed rate within an appropriate range with 15 mm / min in between.

Curve C shows the case where the radius R is 30 mm. In this case, when the feed speed is around 15 mm / min, the plate thickness weighting ratio is about 10%. In order to increase the plate thickness increase rate by 15% or more, the feed speed needs to be high at 55 mm / min, which is not preferable.

Therefore, in the result shown in FIG. 5, the radius R of the curved surface of the processing surface 29 in the processing roll 27 is preferably about 15 mm to 20 mm, and the feed speed is set between 15 mm / min. It is understood that it is desirable that the rate of increase is in the range of no more than 30%. In addition, the condition which the result shown in FIG. 5 holds | maintains is a case where the plate | board thickness of the workpiece | work W is about 4 mm-8 mm. That is, in the case of 4 mm or less, curling tends to occur when trying to mold the disk-shaped workpiece W into a cylindrical shape, and if it exceeds 8 mm, the limit of rolling processing is exceeded, and thus the sheet thickness range is exceeded. do.

As understood by the above description, when the disk-shaped workpiece W fixed to the front end surface of the mandrel 7 is formed into a cup or tubular shape along the outer circumferential surface of the mandrel 7, Applying compressive stress in the radially inward direction to the piece W to shape the workpiece W into a cylindrical shape, and then press the workpiece W against the outer circumferential surface of the mandrel 7 for ironing. In this case, the work piece W is deformed in the compression direction and then subjected to the deformation in the tensile direction to form a spinning process. The work hardening can be suppressed and the molding limit can be increased. Thereby, processing with high precision can be performed.

The invention according to claim 1 of the present invention is a spinning processing method for forming a disk-shaped workpiece fixed to a front end face of a mandrel into a cylindrical shape along the outer circumferential surface of the mandrel, and simultaneously pressing the workpiece on the outer circumferential surface of the mandrel. In the present invention, the radially inward direction is applied to the disk-shaped workpiece to form a cylindrical shape, and the cylindrically shaped workpiece is pressed onto the outer circumferential surface of the mandrel. When forming into a shape, the workpiece is compressed to have a thickness that increases. And when press-working the cylindrically shaped workpiece on the outer peripheral surface of the mandrel, the workpiece is pressed by the mandrel by the working roll, and the working roll is moved along the mandrel, so that the workpiece is stretched and tensioned. The stress acts.

That is, the workpiece is in a cylindrical shape, and the deformation is in the shrinking direction under compression stress during molding, and the deformation is in the direction in which the deformation increases due to tensile stress during pressing. Therefore, work hardening of the work piece can be suppressed and spinning can be performed, and annealing heat treatment is unnecessary as in the prior art, and production efficiency can be improved.

In the invention according to claim 2, in the invention described in claim 1, the compressive stress in the radially inward direction is applied to the disk-shaped workpiece, and when the workpiece is formed into a cylindrical shape, When the working surface formed on the outer circumferential surface is a curved surface having a radius of 15 mm to 20 mm, and the feed speed of the processing roll relative to the work piece is 15 to 22 mm / min, the plate thickness is given when the compressive stress in the radially inward direction is given to the work piece. It can be molded into a cylindrical shape without increasing the increase rate more than necessary and without causing cracks in the workpiece.

The invention according to claim 3 is a machining roll for forming a cylindrical work piece fixed to a front end face of a mandrel into a cylindrical shape along the outer circumferential surface of the mandrel, wherein the outer circumferential surface of the roll has an axial direction and a radial direction Compression stress in the radially inward direction when the workpiece is formed into a cylindrical shape along the outer circumferential surface of the mandrel. Can be given and processed.

In the invention according to claim 4, in the invention according to claim 3, since the radius of the arcuate portion of the machining surface is 15 mm to 20 mm, the sheet thickness increase rate is not increased more than necessary when forming the workpiece into a cylindrical shape. It can be molded.

Claims (4)

In the spinning processing method of forming a disk-shaped workpiece fixed to the end surface of the mandrel into a cylindrical shape along the outer circumferential surface of the mandrel, and simultaneously pressing the workpiece on the outer circumferential surface of the mandrel. A spinning machining method, wherein a disk-shaped workpiece is subjected to a radial stress in the radially inward direction to be molded into a cylindrical shape, and the workpiece is pressed into the cylindrical shape on the outer circumferential surface of the mandrel. The method of claim 1, When the workpiece is formed into a cylindrical shape by applying a compressive stress in the radially inward direction to the disk-shaped workpiece, the machined surface formed on the outer circumferential surface of the processing roll for processing the workpiece is a curved surface having a radius of 15 mm to 20 mm, And a feed rate of the processing roll relative to the work piece is 15 to 22 mm / min. In the processing roll for forming a cylindrical work piece fixed to the end surface of the mandrel in a cylindrical shape along the outer peripheral surface of the mandrel, The processing roll which forms the processing surface for cylindrical shaping | molding which makes the curved surface of the form opened to the outer peripheral surface of the said roll in the axial direction and the radial direction of the said processing roll, and makes an arc shape in cross section. The method of claim 3, The radius of circular arc part of a process surface is 15 mm-20 mm, The processing roll characterized by the above-mentioned.