JP5229909B2 - Spinning method and apparatus - Google Patents

Description

  The present invention relates to a spinning processing method and a spinning processing apparatus for carrying out the same.

In the spinning processing method, in the ironing spinning processing in which the processing roller is moved along the tooling die along the tool path of one pass, the thickness of the workpiece workpiece is determined according to a law called sine rule.
For example, when a conical shape having a half-width α is formed by this processing method, the thickness t of the processed part is uniformly t = t ₀ sin (in the circumferential direction according to the sine rule depending on the thickness t ₀ of the base plate. α). In the drawing spinning process in which molding is performed in multiple stages using multiple tool passes, the thickness can be reduced or increased from the plate thickness by setting the pass, but the thickness is still limited to a uniform distribution in the circumferential direction.

  By the way, in the product molded by spinning, for example, in order to form a portion where a large load is applied by contacting with other parts, a connecting portion with other members, a welding portion, etc. For some of the side surfaces, the thickness needs to be increased by increasing the thickness, or conversely, it may be necessary to reduce the thickness to reduce weight and cost. In the processing method, the cross section perpendicular to the axis of the product has to be processed to a uniform thickness in the circumferential direction, and it has not been possible to meet such a demand.

  Patent Document 1 proposes a method of forcibly reducing a part of a product between a mold and a roller by rotating ironing. In this method, the thickness is determined by a gap between the mold and the roller. In this case as well, the circumferential thickness is uniform.

Patent Document 2 proposes a method for forming a product having a non-uniform thickness distribution in the circumferential direction by spinning, and forming a recess in the mold and injecting the material to thicken only that portion. .
However, this method requires a processing apparatus with a large roller driving thrust to force the material to flow, and it is difficult to control the thickness distribution over the entire product and to apply to a thin plate.

  Patent Document 3 proposes a method in which a blank having a non-uniform thickness in the circumferential direction is created in advance by welding and a spinning process is proposed. However, it takes time and cost to create the blank.

JP-A-7-88583 JP 2002-86233 A JP 2002-153930 A

  The present invention relates to the surface of a partial region in the circumferential direction even if a processing device having a relatively small processing force is used by spinning processing that moves a processing roller in one pass from a base plate having a uniform plate thickness including a thin plate. It is an object of the present invention to realize a spinning method capable of forming a product having a non-uniform thickness distribution, such as making a portion where strength is required thick.

Therefore, in the present invention, in order to solve the above-described problem, spinning is performed by attaching a plate-shaped metal workpiece to a main shaft and rotating it, pressing a processing roller, and forming a product having the main shaft as a central axis. in the processing method, based on the rotation angle signal from the motor with the rotational angle sensor to drive the spindle in synchronization with the rotation angle of the workpiece, the contact point of the processing rollers and the workpiece, the center line of the main spindle to draw a closed orbit along with your Keru product shape in a plane intersecting at a predetermined inclination angle against, by advancing or retracting the working roller in said main axis and radially, circumferentially uneven wall A product with a thickness distribution was formed.

  Further, in the above spinning method, an inclination in which a plane including the trajectory of the contact point between the workpiece and the processing roller intersects the center line of the main shaft based on the shape and thickness distribution of the final product by the spinning processing. The angle was decided.

At that time, when the shape of the final product is a cone or truncated cone with a cone half angle α, the workpiece thickness is t ₀ and the thickness of the thickest part or the thinnest part of the product is to be td , An inclination angle φ of the plane including the trajectory of the contact point between the workpiece and the processing roller intersecting the center line of the main shaft,
I asked for it.

In addition, as a spinning processing apparatus that suitably performs the spinning processing method described above, a motor with a rotation angle sensor, a main shaft that is driven by the motor and rotates with a plate-shaped metal workpiece mounted thereon, and a contact with the workpiece A spinning processing device comprising: a processing roller for forming a product having the main shaft as a central axis; an actuator for driving the processing roller in the main shaft direction and the radial direction; and a storage device for target shape data of the product A control device for controlling the actuator based on the target shape data and target wall thickness data stored in the storage device, and in synchronization with the rotation angle of the workpiece, the contact point between the workpiece and the processing roller but to draw a closed orbit along your Keru the target shape data in a plane intersecting at a predetermined inclination angle with respect to the center line of the main spindle, It was that a control means for advancing or retracting the Engineering roller spindle and radially.

The present invention can produce the following effects.
(1) The present invention can adjust the thickness of the workpiece to a non-uniform thickness distribution in the circumferential direction, unlike the conventional spinning method, regardless of the shape of the product. If there is a part where the thickness is to be increased or decreased, the thickness of the part can be adjusted by using this processing method without changing the thickness distribution of the base plate.
(2) In the present invention, since the thickness is changed by using the natural displacement deformation of the plate instead of forcibly flowing the material, it can be applied to a thin plate, and the driving thrust of the roller is relatively small. It can also be executed on the device.
(3) In the present invention, when the shape of the product is a cone or a truncated cone, a simple calculation formula is obtained from the thickness of the cone half-angle and the base plate and the product thickness of the thickest part or the thinnest part in the circumferential direction. The tool trajectory during machining can be obtained.

It is a schematic plan view which shows an example of the spinning processing apparatus which concerns on this invention. It is explanatory drawing which showed the mode of the contact of the workpiece | work and processing roller in this invention. It is explanatory drawing which showed the comparison of the tool path in this processing method and the conventional processing method. It is explanatory drawing which showed the example of the helical tool path | route in process. It is the photograph which showed the example of the product by this processing method. It is explanatory drawing which showed the transition for a molding state, and the symbol for thickness estimation and adjustment. It is explanatory drawing showing the relationship between the inclination of a base plate, a cone half angle, and the angle of a product side surface. It is a graph which shows the theoretical value and measured value of thickness ratio in an actual shaping | molding result.

The present invention can be implemented in a synchronous spinning process in which machining is performed by synchronizing the movement of a spindle to which a workpiece is attached and a tool.
FIG. 1 is a schematic plan view showing an example of the configuration of a processing apparatus that implements the spinning processing method of the present invention. Here, the spinning processing apparatus 10 finally processes the workpiece 1 from the flat plate 1a having an initial shape into a truncated cone shape 1b having the main shaft 3 as a central axis.

The workpiece 1 is sandwiched and fixed between a jig 2 and a main shaft 3 and is rotated together with the main shaft 3 by a motor 4. The motor 4 includes a rotation angle sensor such as an encoder that detects the rotation angle θ.
The rod-like processing roller 5 has a spherical processing surface at the tip, and is moved forward or backward in the radial direction of the flat plate 1a by a radial linear motion table 6 driven by an actuator such as a ball screw or a hydraulic cylinder. Further, the linear motion table 6 in the radial direction is advanced or retracted in parallel with the main shaft 3 by the linear motion table 7 in the main shaft direction.
These linear motion tables 6 and 7 are each provided with a displacement sensor such as an encoder for detecting a feed amount. The driving of the linear motion tables 6 and 7 is controlled by a control device that controls actuators such as the ball screw and the hydraulic cylinder.

That is, the control device uses a computer, receives data from the rotation angle sensor of the motor and the displacement sensors of the linear motion tables 6 and 7, and generates control signals according to control software installed in advance. Controls the driving of actuators such as the ball screw and hydraulic cylinder.
The characteristic configuration of the spinning processing method according to the present invention is based on the premise that the workpiece 1 is processed into a final shape such as a truncated cone shape having the main shaft 3 as a central axis, while processing the portion where the thickness is to be adjusted. The locus of the contact point between the workpiece 1 and the processing roller 5 is to draw a closed trajectory in a plane that is not perpendicular to the main axis S but inclined.

  FIG. 2 shows a state of contact between the workpiece 1 and the processing roller 5 in the spinning processing method and apparatus according to the present invention. In synchronization with the rotation angle θ of the workpiece 1, the feed displacement z in the main axis direction and the feed displacement x in the radial direction of the processing roller 5 are controlled. The trajectory of the contact point between the workpiece 1 and the processing roller 5 draws a closed trajectory in a plane that obliquely intersects the main axis S.

FIG. 3 shows how the closed trajectory of the contact point between the machining roller and the workpiece changes when the workpiece is fixed in the conventional spinning method (right) and the method according to the present invention (left). It is a representation.
In the conventional spinning method, the closed trajectory of the contact point is always in a plane perpendicular to the principal axis.
On the other hand, in the present invention, the plane where the closed orbit exists is inclined with respect to the main axis at the location where the thickness is to be adjusted, and the thickness is changed by changing the inclination angle. At this time, a representative point of the closed orbit such as the center of the original position of the base plate can be determined, and the change in the inclination angle of the plane can be represented by the shape of the axis along which the point moves.

  In actual machining, the movement of the tool on the closed track and the feed in the axial direction are combined, and the tool track draws a spiral track with respect to the workpiece as shown in FIG. In the conventional spinning method (right), the tool path draws a straight spiral, and the plane where the unmachined part of the workpiece is placed is always perpendicular to the main axis, so the thickness of the workpiece is uniquely determined. . In this machining method (left), it is possible to set a tool path that is curved relative to the product even if the product shape is the same. In this case, the plane on which the unprocessed part of the work is placed is projected with the inclination changed with respect to the original position.

The tool trajectory to be given to the processing machine is mainly determined by the shape of the axis on which the representative point of the closed trajectory moves, the shape of the product, and the shape of the tool. The procedure of the method for calculating the tool path is as follows. This method can be used without being limited to a basic shape such as a cone.
1. The shaft shape C (s) is defined using the machining progress s that continuously changes from the start (0) to the end (1) as a parameter.
2. A function T (s) that defines a subparameter t for the rotation angle on the closed track is defined using the machining progress s as a parameter.
3. The tool path is calculated by the following procedure while continuously increasing the machining progress.
(1) The subparameter t is obtained from the calculation of T (s).
(2) The position and inclination of the projection plane are obtained by calculation from the shape C (s) of the axis and the differentiation with respect to s.
(3) When the projection plane and the product shape come into contact with each other via the tool shape, the position of the contact point between the tool and the product shape, particularly represented by the subparameter t, is obtained.
(4) The tool position obtained by adding the correction amount of the tool shape to the contact point position from the contact point position, the product shape, the tool shape, and the like is output as a point on the tool path. When a tool having a spherical tip is used, the tool shape can be easily corrected.

  Thereby, the tool path can be calculated. Since the length of the tool path between each data can be calculated from the calculation results, the tool feed speed is calculated so that the speed of the contact point between the tool and the product shape is constant, and the reciprocal integral calculation is performed. The time required for processing can be obtained from

  An example of a product by this processing method is shown in FIG. When processing without preparing a mold, if the base plate is bent as shown in the photograph, the strength of the base plate increases and wrinkles are unlikely to occur in the unprocessed part of the workpiece, so that it is easy to form. When using a mold, the accuracy of the inner surface can be improved, but it is necessary to add a thickness offset to the product shape, so the wall thickness model formula used in the wall thickness adjustment method described later If the offset amount is obtained in advance and added to the tool correction, it can be expected that molding is easy.

As shown in FIG. 6, when a product shape having a cone half angle α is processed from a base plate having a thickness t ₀ , an axial shape that is partially straight and inclined by φ with respect to the normal direction of the original base plate is set. . As shown in FIG. 7, the angle formed between the normal to the base plate (dashed line) being processed and the side surface of the product is α−φ at the minimum and α + φ at the maximum. If the sine rule is expanded, the thickness of the product corresponding to each position is
It is. FIG. 8 shows a graph in which the ratio of the actually measured base plate thickness and the theoretical value calculated from the equations (1a) and (1b) are plotted for the product shown in FIG. This was formed from a base plate with a nominal plate thickness t ₀ of 1.5 mm so as to partially increase or decrease the partial conical shape with a half angle of 20 ° (top diameter 50 mm, base diameter 100 mm). It is a product. As for the wall thickness ratio, the theoretical value of the broken line and the measured value of the white circle and the black circle almost coincide.

When calculating backward from the left side of equation (1), if you want the product part thickness to be td on one side,
The inclination may be determined so that However, φ must be smaller than α in absolute value. In this case, the thickness of the straight line portion is the smallest in the circumferential direction when φ> 0, and the thickest when φ <0. Also, at this time, the thickness at the opposite position across the shaft on the product is
Set to Contrary to the straight line portion, the opposite side is thickest in the circumferential direction when φ> 0, and thinnest when φ <0.

It is difficult directly to set the thickness of the portion where the shape of the shaft is not linear to a desired value. However, in the present invention, as long as the shape of the product and the shape of the shaft are given, the thickness can be estimated from the thickness model formula for the entire processed part of all product shapes. As shown in FIG. 6, at a certain degree of processing progress, the distance from the tangential plane of the shaft to the point on the product shape at that time is r, the length of the shaft is ζ, the inclination of the normal plane, that is, the projected plane is φ, Assuming that ζ ′, φ ′, and r ′ are the derivatives relating to the respective processing progress s, the thickness at that point can be predicted from the following thickness model formula.

Therefore, for this model formula, if φ is obtained by iterative convergence calculation using a neural network system or the like, it is possible to obtain a product having a thickness close to a desired thickness.
Although the spinning processing method according to the present invention has been described based on the embodiments, the present invention is not limited to such embodiments, and various implementations can be made within the scope of the technical matters described in the claims. Needless to say, there is a mode of.
For example, the product is not limited to a conical shape, and can have various cross-sectional shapes such as an ellipse, an eccentricity, and a polygon.

  Since the spinning method according to the present invention is configured as described above, it does not create a blank having a non-uniform thickness in the circumferential direction in advance by welding, and causes a significant cost increase as a spinning device. In the spinning process, the thickness of parts and products can be partially increased or decreased, making it possible to form a wider variety of products such as partial reinforcement of products and weight reduction by thinning. Therefore, it can be used for a wide range of purposes.

1 Workpiece 1a Flat plate (material)
1b Product shape of truncated cone shape 2 Jig 3 Spindle 4 Motor 5 Processing roller 6 Linear motion table (radial direction)
7 Linear motion table (spindle direction)
10 Spinning machine

Claims (4)

In a spinning process method in which a plate-shaped metal work is attached to a main shaft and rotated, and a processing roller is pressed to form a product having the main axis as a central axis.
Based on the rotational angle signal from the motor with the rotational angle sensor to drive the spindle in synchronization with the rotation angle of the workpiece, the contact point of the processing rollers and the workpiece, predetermined with respect to a center line of the main spindle to draw a closed orbit along with your Keru product shape in a plane intersecting at an oblique angle, the working roller by advancing or retracting the spindle and radially and circumferentially non-uniform thickness distribution of the product A spinning processing method characterized by molding the material.   Based on the shape and thickness distribution of the final product by spinning processing, the inclination angle at which the plane including the trajectory of the contact point between the workpiece and the processing roller intersects the center line of the main shaft is determined. The spinning method according to claim 1. When the shape of the final product is a cone or a truncated cone with a cone half angle α, the plate thickness of the workpiece is t0, and the thickness of the thickest part or the thinnest part of the product is td, An inclination angle φ intersecting the center line of the main axis of the plane including the trajectory of the contact point between the workpiece and the processing roller,
The spinning method according to claim 2, wherein the spinning method is obtained by: A motor with a rotation angle sensor, a main shaft that is driven by the motor and rotates by mounting a plate-shaped metal workpiece, and a processing roller that contacts the workpiece and performs a forming process on a product having the main axis as a central axis A spinning processing apparatus comprising: an actuator for driving the processing roller in the main axis direction and the radial direction; and a storage device for target shape data of a product.
Based on the target shape data and target wall thickness data stored in the storage device, the control device for controlling the actuator is synchronized with the rotation angle of the workpiece, and the contact point between the workpiece and the processing roller is to draw a closed orbit along your Keru the target shape data in a plane intersecting at a predetermined inclination angle with respect to a center line of the spindle, a control means for advancing or retracting the working roller in said main axis and radially A spinning device characterized by comprising.