JPH07328801A - Lathe turning method and blade tool drive device - Google Patents

Abstract

PURPOSE:To provide a lathe turning method for producing chips having such a shape as enabling safety security of works and continuous driving of a lathe turning device. CONSTITUTION:After a blade tool 3 is taper transferred from the lowest point (the minimum point of the distance between a central axis 41 and the blade tool 3) to the highest point (the maximum point of the same), it is taper transferred again to the following lowest point. The first lathe turning process is performed by periodically repeating this action as a unit block so as to form the surface of a work 4 into a corrugated shape. Secondarily, the second lathe turning process is performed by linearly transferring the blade tool 3 while holding it at the lowest point so as to remove the corrugated surface. Torsional phenomena based on residual stress is thus generated on chip 5 which is made into such a shrunk shape as hard to wind around the work 4, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turning method and a method for turning a non-ferrous material such as copper or aluminum alloy, which enables continuous turning for a long time without damaging a turning device or a work material. The present invention relates to a blade driving device for realizing the above.

[0002]

2. Description of the Related Art Turning is a method of turning a surface layer of a rotating work material with a cutting tool to deform it into a predetermined shape, and chips are inevitably generated during the working. The shape of the chips is roughly classified into a continuous type or a discontinuous type depending on the driving mode of the cutting tool and the material of the work material. Here, the continuous type is a shape in which chips are continuous without being partially cut, and the discontinuous type is a shape in which chips are partially cut.

FIG. 5 is an explanatory view of a conventional general turning method, in which a rotating work material (hereinafter referred to as a work).
The state in which the surface layer of 50 is linearly turned using the cutting tool 53 supported by the cutting tool support 52 is shown. In the illustrated example, the relative displacement amount (hereinafter, feed amount) of the cutting tool 53 in the horizontal direction with respect to the rotation shaft 51 of the work 50 is constant in time, and the cut amount of the work 50 into the surface layer is also constant. The shape of the chips 54 generated by turning is a linear continuous type as shown in the drawing.

Such a turning method has an advantage that a desired shape can be machined by turning once, but as the turning progresses, the chips 54 become gradually longer and may be wound around the work 50. . If the work is continued while the wrapping of the chips 54 is left unattended, chipping of the cutting tool 53 occurs, causing damage to the cutting tool 53 and damage to the workpiece 50. Therefore, conventionally, when the chips 54 reach a certain length or when any abnormality derived from the continuous chips is detected, the chips 54 of the blade 53 are actuated so that the chips 54 are predetermined. It was common to employ a configuration in which cutting is performed at intervals of 10 to prevent the winding.

[0005]

However, even if the above configuration is adopted, the chip breaker or the like may not work effectively depending on the material of the work 50. In this case, when an abnormality occurs, the chips 54 wind around the work 50,
There is a problem in that the cutting tool 53 is damaged and the processing is forced to be interrupted for removing the wound chips. Moreover, the work of removing the wrapping chips is a dangerous work that may be torn, and there is a problem in terms of safety.

Due to such a problem, even if a turning machine such as a numerically controlled lathe or an automatic lathe, which is originally capable of continuous operation, is installed, it is practically difficult to operate it continuously for a long time. However, there was a problem that the turning efficiency could not be improved.

An object of the present invention is to provide a turning method which eliminates the above problems and produces chips having a shape which enables continuous operation of a turning apparatus. Another object of the present invention is to provide a cutting tool driving device having a configuration suitable for carrying out the above-described turning method.

[0008]

The turning method of the present invention which achieves the above object, is a cutting tool whose relative position to the surface layer of a rotating workpiece is displaced at a constant speed in a direction parallel to the axis of rotation of the workpiece, In a turning method using a device provided with means for controlling the tip position of the cutting tool that points the rotation axis of the work, the tip position of the cutting tool is alternated in a direction away from the rotation axis and a direction approaching the rotation axis. And a first turning step of periodically changing the surface layer of the work into a wavy shape, and a wavy shape of the work that has undergone the first turning step while keeping the distance between the tip end position of the cutting tool and the rotary shaft constant. And a second turning step for removing the surface layer.
This kind of turning method, like copper and aluminum alloy,
It is especially effective for non-ferrous materials that are relatively soft and sticky.

The point at which the distance between the tip of the cutting tool and the rotation axis on which the tip is directed in the first turning step is maximized is preferably near the surface layer of the workpiece before machining. More preferably, the displacement ratio of the tip of the cutting tool in the first turning step is the maximum when the feed amount from the point where the distance from the rotation axis of the tip is the minimum to the maximum is 1 The feed amount from one point to the next minimum point is set to about 3, and the angle between the slope from the maximum point to the next minimum point and the rotation axis is about 27 degrees.

Further, a cutting tool driving device of the present invention which achieves the above-mentioned other object is a device for driving a cutting tool for turning a surface layer of a rotating work, and a tip of the cutting tool which is directed to a rotation axis of the work. First control means for alternately and periodically displacing the blades in a direction away from the rotation axis and a direction approaching the rotation axis, and second control means for holding the tip position of the cutting tool at a constant distance from the rotation axis. And at least.

In the above arrangement, the first control means may be, for example, the feed amount from the point where the distance from the rotary shaft of the tip of the cutting tool to the point where the distance is the maximum and the point where the distance is from the maximum point to the next minimum point. It is characterized by including a ratio setting unit for arbitrarily setting a ratio to the feed amount of the blade, and a lifting control unit for periodically controlling the lifting time of the cutting tool according to the set ratio.

[0012]

In the turning method of the present invention, the turning of the work is performed in two stages. In the first turning step, the tip end position of the cutting tool is alternately and periodically changed in a direction away from and a direction approaching the rotation axis of the work, and the surface layer of the work is turned in a wavy shape. As a result, the cutting amount of the work changes periodically with respect to the feed amount of the cutting tool, so the stress generated in the surface layer of the work constantly fluctuates, and the residual stress remaining on the chip side also varies, causing the chips to twist and shrink. It becomes a shape. In the second turning step, the corrugated surface layer of the work that has undergone the first turning step is removed by keeping the distance between the tip position of the cutting tool and the rotary shaft constant. That is, turning is performed again with a constant cutting depth,
Since the surface layer of the work is formed in a wavy shape in the first turning step, the thickness of the chips during turning gradually changes, and like the first turning step, twisted and shrunk chips are generated. Since the shredded chips have a shape that does not easily wind around the work, continuous turning, which has been a problem in the past, can be performed.

If the point at which the distance between the tip of the cutting tool and the axis of rotation of the work pointed by the tip is maximized is near the surface layer of the work before machining, the stress and the weight of the scrap itself cause the scrap. Since it becomes easier to cut, the shape of the chips changes to a discontinuous shape, and the above-mentioned winding is more effectively suppressed.

Further, in the cutting tool driving device of the present invention, the feed rate from the point where the distance from the rotary shaft of the cutting edge of the cutting tool to the point where the cutting tool tip reaches the maximum is set in the ratio setting section which constitutes the first control means. By setting the ratio of the feed amount from the maximum point to the next minimum point and periodically controlling the lifting time of the cutting tool in accordance with the ratio set in the lifting control unit, the first
A turning process can be performed. The second control means is
The second turning process is performed on the workpiece that has undergone the first turning process.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a configuration diagram of essential parts of a turning apparatus according to an embodiment of the present invention. This turning apparatus has a blade driving device 1, a blade supporting portion 2, a blade 3, and a rotary drive mechanism (not shown) for rotationally driving a work 4. The work 4 is made of a non-ferrous material such as copper or aluminum alloy. It should be noted that a configuration may be considered in which the workpiece 4 is moved at a constant speed in the direction of the rotation axis 41 during turning to relatively change the feed amount of the cutting tool 3, but in the present embodiment, for convenience, the cutting tool 3 is parallel to the rotation axis 41. An example in which the vehicle is moved at a constant speed in the direction will be described.

The cutting tool driving device 1 is a device for controlling the feed amount and the cutting amount of the cutting tool 3 which is directed to the rotary shaft 41 to form the corrugated surface layer of the work 4 as shown in the drawing. A ratio setting unit 11 that arbitrarily sets the ratio of the feed amount from the point where the distance from the rotary shaft 41 of the tip is the minimum point to the maximum point and the feed amount from the maximum point to the next minimum point.
And a lifting control unit 12 that periodically controls the lifting time of the cutting tool 3 according to the set ratio.

FIG. 2 is a diagram showing the locus of the cutting tool 3 controlled by the cutting tool driving device 1. The cutting start point that is the minimum point is X1, and the cutting middle point that is the maximum point is X.
2. The end point of the next minimum point is set to X3, and a block consisting of these points is repeated for a predetermined period. In FIG. 2, as a preferable numerical example obtained by the experiment, the width between the minimum point and the maximum point is 3 [mm], the feed amount from X1 to X2 is 5 [mm], and the feed amount from X2 to X3. Although the amount is set to 15 [mm], if the ratio X1-X2: X2-X3 of the feed amount between points is set to approximately 1: 3, the residual stress effect described below can be more significantly exhibited. The setting to the setting unit 11 is not necessarily limited to the above numerical example.

FIG. 3 is a flow chart showing an example of control contents in the elevating control section 12, and S represents a processing step. Here, an example of executing the first turning process will be described.

First, the cutting tool 3 is set at the turning start point (S101). This turning start point is, for example, a point where the distance between the tip of the cutting tool and the rotary shaft 41 at that time is the minimum (starting point X1). Next, the feed amount and the cutting amount of the cutting tool 3 are controlled according to the set values of the ratio setting section 11 via the cutting tool supporting section 2, and the distance between the tip of the cutting tool and the rotating shaft 41 is maximized (the intermediate point X2). The taper is moved in the direction (S102). That is, the blade 3 is raised so that the distance between the tip of the blade and the rotary shaft 41 gradually increases. Next, it is determined based on the set value of the ratio setting unit 11 whether or not the tip of the cutting tool has reached the maximum point (S103), and if not reached, taper movement in the same direction is continued. On the other hand, when the maximum point is reached, the taper movement direction of the cutting tool 3 is changed to move to the next minimum point (the end point X3) (S104).
That is, the blade 3 is lowered. After that, it is determined whether the tip of the cutting tool has reached the minimum point (X3) based on the set value of the ratio setting unit 11 (S105). If not, the taper movement in the same direction is continued, and when the minimum point is reached. Determines whether the turning end condition is satisfied, for example, whether all the surface layers of the work 4 have been turned (S106), and when the turning condition is not satisfied, the processes of S102 to S106 are repeated. When the turning condition is satisfied, the cutting tool 3 is returned to the predetermined position and the lifting control is ended.

By operating the elevating controller 12 as described above, the surface layer of the work 4 is formed into a wavy shape as shown in FIG. At that time, the chips 5 are successively generated from the turning portion, but a twist phenomenon occurs in the chips 5 due to a change in the residual stress of the surface layer due to work hardening. Then, the chips 5 repel from the surface layer of the work 4 to be in a contracted shape and become clumped in the vicinity of the tip of the cutting tool, which makes it difficult to wind around the work 4. The ratio of the feed amount for more significantly exerting the shrinking effect due to the residual stress of the chips is the above-mentioned ratio of 1: 3, and changing the ratio alleviates the above effect. However, the value does not have to be exact,
An approximate value is enough.

When the taper movement of the cutting tool 3 changes toward the next minimum point (end point: X3) at the intermediate point X2, the chips 5 are cut at this point. In order to ensure the cutting, it is preferable that the intermediate point X2 is on the surface layer of the work 4 or is sufficiently close to the surface. By doing so, the chips 5 are automatically cut by their own weight and stress change, and the winding around the work 4 is more effectively prevented.

As shown in FIG. 4, a commercially available general-purpose cutting tool is used as the cutting tool 3 and in order to realize the most efficient turning, the slope from the intermediate point X2 to the end point X3 and the rotary shaft 41 are arranged. The angle formed by the parallel lines 42, that is, the taper angle θ is preferably 27 degrees. When the taper angle exceeds 27 degrees, the commercially available cutting tool angle is usually 30 degrees, so that the work 4 and the cutting tool 3 slide and wear and damage of the cutting tool 3 occur, and conversely, This is because the cutting efficiency decreases when the taper angle is 27 degrees or less. However, this numerical value does not necessarily have to be exact, and an approximate value is sufficient.

In the present embodiment, after the first turning step described with reference to FIG. 3, the second turning step is applied to the surface layer of the work 4. In the second turning step, specifically, the cutting amount of the cutting tool 3 is kept constant, and the cutting tool 3 is linearly moved from the starting point X1 to the ending point X3 in order to remove the corrugated surface of the work 4. . The thickness of the chips thus generated gradually changes as the turning progresses. Therefore, as in the case of the first turning process in which the turning amount is changed and turning is performed, the chipping phenomenon occurs in the chips, making it difficult to wind around the work 4.

As described above, in the turning apparatus of this embodiment, the work 4 is subjected to the first and second turning steps by using the cutting tool driving apparatus 1. Therefore, the shape of the chips produced during turning is The work 4 has a shape that is difficult to be wound around, so that interruption of processing and chipping of the cutting tool 3 are suppressed. As a result, the turning operation can be performed continuously without interruption, and as a result, the turning time can be greatly reduced.
Further, since tool breakage and wear are reduced, the work 4 is less adversely affected and the running cost is reduced. Further, since it is not necessary to perform the work of removing chips, which is dangerous, safety is improved.

[0025]

As is apparent from the above description, according to the turning method of the present invention, in the first turning step, the tip position of the cutting tool is alternately and periodically arranged in the direction away from and toward the rotation axis of the workpiece. Instead, the surface layer of the work is turned into a wavy shape, and in the second turning process, the distance between the tip position of the cutting tool and the rotation axis is kept constant to remove the wavy surface layer of the work that has undergone the first turning process. The resulting chips are twisted and contracted by the residual stress, which has the effect of making it difficult to wind around the work. This makes it possible to secure work safety and realize continuous turning, which have been issues in the past.

Further, according to the turning method of the present invention, the point where the distance between the tip of the cutting tool and the rotation axis of the work pointed by the tip is maximized is near the surface layer of the work before machining. Due to the residual stress and the weight of the chips themselves, the chips are easily cut, and the chips change into a discontinuous shape, so that the above-mentioned winding is effectively suppressed.

Further, in the first turning step, the feed amount from the maximum point to the next minimum point is the feed amount from the point where the distance between the tip of the cutting tool and the rotation axis of the workpiece becomes the maximum point to the maximum point. The blade tool is driven so that is approximately 3 times, and the angle formed by the slope from the maximum point to the next minimum point and the rotation axis of the work is approximately 27 degrees. It is possible to realize the most efficient turning by using the general-purpose cutting tool.

Such a turning method can be easily carried out by the first control means and the second control means of the cutting tool driving device of the present invention. Therefore, although continuous operation is possible in principle, continuous operation can be performed safely for a long time by applying the present invention to a numerically controlled lathe or an automatic lathe, which has been extremely difficult in the past. And it becomes possible to perform easily.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of a turning apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a trajectory of a cutting tool controlled by a cutting tool driving device of the present embodiment.

FIG. 3 is a flowchart showing a processing example of a lifting control unit which is a component of the cutting tool driving device of the present embodiment, for example, a flow of a first turning process.

FIG. 4 is a partial enlarged view showing a state of a turning portion according to the present embodiment.

FIG. 5 is an explanatory view of a turning method according to a conventional method.

[Explanation of symbols]

 1 Cutting Tool Driving Device 11 Ratio Setting Section 12 Elevating Control Section 2 Cutting Tool Supporting Section 3 Cutting Tool 4 Workpiece (Work Material) 41 Rotating Shaft

Claims (6)

[Claims] 1. A cutting tool whose relative position to a surface layer of a rotating work material is displaced at a constant speed in a direction parallel to a rotation axis of the work material,
In a turning method using a device provided with a means for controlling the tip position of the cutting tool that points the rotation axis of the work material, a direction in which the tip position of the cutting tool moves away from the rotation axis and a direction approaching the rotation axis. A first turning step of alternately and periodically changing the surface layer of the work material into a wavy shape, and the first turning step while keeping the distance between the tip position of the cutting tool and the rotary shaft constant. A second turning step for removing a corrugated surface layer of a work material, and a turning method. 2. The point at which the distance between the tip of the cutting tool and the rotation axis on which the tip points in the first turning step becomes maximum is near the surface layer of the work material before machining. The turning method according to claim 1. 3. The displacement ratio of the tip of the cutting tool in the first turning step is calculated when the feed amount from the point where the distance of the tip from the rotation axis is the minimum to the point where the distance is the maximum is 1. The turning method according to claim 1 or 2, wherein the feed amount from the maximum point to the next minimum point is a ratio of about 3. 4. The turning method according to claim 3, wherein an angle formed by the slope from the maximum point to the next minimum point and the rotation axis is approximately 27 degrees. 5. A device for driving a cutting tool for turning a surface layer of a rotating work material, comprising: a direction in which a tip of the cutting tool, which points the rotation axis of the work material, is away from the rotation axis; and the rotation axis. A cutting tool driving device comprising at least first control means for displacing the cutting tool alternately and periodically and a second control means for holding the tip position of the cutting tool at a constant distance from the rotation axis. 6. The feed amount from a point where the distance of the tip of the cutting tool from the rotation axis is the maximum to the point where the distance is the maximum and the feed amount from the maximum point to the next minimum point. 6. The blade tool driving device according to claim 5, further comprising: a ratio setting unit that arbitrarily sets a ratio between the blade and the blade, and a lifting control unit that periodically controls the lifting time of the blade according to the set ratio.