JP7332150B2 - Synthetic resin cutting method and cutting device - Google Patents

Description

The present invention relates to a synthetic resin cutting method and a cutting apparatus, and more particularly, to a novel cutting method and cutting apparatus for various synthetic resins including fiber-reinforced resins, which can suppress the generation of residue due to cutting. It is.

Fiber-reinforced resins, which are composite materials of synthetic resins and fibers, have been known for some time. Since it is easy to impart various characteristics by combining these, it is being considered for use in various fields such as construction, vehicles, aircraft, ships, playground equipment, and electrical parts. For example, GFRP using glass fiber as the reinforcing fiber, AFRP using aramid fiber, BFRP using boron fiber, and CFRP using carbon fiber can be used.

By the way, when fiber reinforced resin is used for parts in various fields, after primary processing by molding, in order to achieve the desired shape and dimensions, peripheral cutting, drilling, grooving, dicing, etc. Secondary processing is often required. In this specification, the term "cutting" is used generically to include processing that leaves an uncut portion, such as grooving and bottomed hole drilling.

However, with fiber reinforced resins, there is a problem that mechanical secondary processing is difficult because the mechanical properties of the base material made of synthetic resin and the reinforcing material made of fibers are different. In some cases, the application of the In particular, compared to fiber-reinforced resins that use thermoplastic resins as the base material, fiber-reinforced resins that use thermosetting resins as the base material are generally difficult to cut, making secondary processing more difficult. .

Specifically, as a mechanical cutting method for fiber reinforced resin, for example, "cutting with a band saw, diamond disc, etc.", "end milling", "drilling", and "AWJ processing" are at the practical stage. Applications such as "laser processing", "EDM wire processing", and "blasting" are also being considered. However, "laser processing" has the problem that the equipment is expensive and the thermal effect on the workpiece is unavoidable. Further, "AWJ machining" and "blast machining" have a problem of equipment cost and a problem of machining accuracy because the machined surface of the workpiece tends to be tapered. Furthermore, since "EDM wire processing" is an underwater process, there is a problem that it is impossible to avoid burdens on post-processes such as processing equipment and drying. In addition, "cutting with a band saw, diamond disc, etc.", "end milling", and "drilling" can keep equipment costs relatively low, but delamination between the base material and the reinforcing material In addition to being difficult to control, it is difficult to avoid dusting of chips due to cutting, which may lead to environmental problems such as health hazards for workers.

In addition, Japanese Patent Application Laid-Open No. 2016-140964 (Patent Document 1) discloses a method of punching in a state where the base material is simply heated to near the thermal deformation temperature as a secondary processing method of fiber reinforced resin. there is However, the invention described in Patent Document 1 is merely a processing technology premised on thermoplastic resin in the first place. Due to the difficulty of setting the temperature, punching speed, etc., delamination often occurs between the reinforcing material and fluffing, which has still hindered its adoption at actual sites.

By the way, even if the object to be processed is a synthetic resin that is not fiber-reinforced, the present invention can be significantly applied. That is, the various processing methods described above can also be applied to the cutting of synthetic resins that are not reinforced with fibers. It was difficult enough to require experience. Particularly appropriate processing conditions vary depending on various conditions such as the material, shape, and member thickness of the synthetic resin, the material, shape, and state of the processing tool, and the processing temperature.

Specifically, in order to efficiently cut the workpiece, it is necessary to increase the cutting speed. However, if the cutting speed is increased, processing defects such as fluffing and cracking are likely to occur in the workpiece, and there is also a risk of damage to the processing tool. For this reason, even skilled processors have to cut at a low speed in anticipation of safety, and the current situation is that sufficient processing efficiency has not been realized. In particular, when the workpiece is made of a new material, or when the thickness changes in the cutting direction, it has been more difficult to control the machining including the setting of efficient machining conditions.

JP 2016-140964 A

Here, the present invention has been made against the background of the above-mentioned circumstances, and the problem to be solved is to easily set good processing conditions when cutting an object made of synthetic resin. To provide a novel cutting method and cutting apparatus capable of

In addition, a specific aspect of the present invention (invention described in subclaims) is a novel fiber-reinforced resin that can be widely applied to secondary processing of various fiber-reinforced resins and can suppress the generation of cutting chips. Another object of the present invention is to provide a cutting method and a cutting apparatus.

Hereinafter, aspects of the present invention that have been made to solve such problems will be described. In addition, each component adopted in each aspect described below can be adopted in any possible combination.

That is, in the first aspect of the present invention, when cutting an object made of synthetic resin, the cutting edge of a processing tool is pressed against the object to apply ultrasonic vibration to the processing tool, and the The relative feed in the cutting direction of the cutting edge with respect to the workpiece is speed-controlled using the degree of reduction in yield strength of the workpiece as an index , and the index corresponding to the degree of reduction in yield strength of the workpiece. The present invention is characterized by a synthetic resin cutting method utilizing a load signal of an ultrasonic oscillator that applies the ultrasonic vibration .

According to the cutting method of this aspect, by pressing the ultrasonically vibrated cutting blade against the workpiece at a low feed rate, the synthetic resin that is the base material can be efficiently heated and the proof stress can be reduced. After that, by pressing the cutting edge at a high feed rate, the workpiece can be efficiently cut.

It should be noted that the object to be processed in this aspect is irrespective of the presence or absence of fiber reinforcement. For example, in the case of an object to be processed made of a synthetic resin that does not have reinforcing fibers, the properties such as toughness of the object to be processed are unknown, or the performance of the processing tool and the state of the cutting edge are unknown. Also, by applying appropriate ultrasonic vibrations to the machining tool, the feed of the cutting edge is automatically appropriately adjusted for machining. Therefore, it is possible to cut various synthetic resin materials with appropriate processing efficiency and good processing accuracy without requiring advanced knowledge and experience.
Further, according to the cutting method of this aspect, when cutting by pressing the ultrasonically vibrated cutting blade against the object to be processed, the ultrasonic vibration of the cutting blade corresponds to the degree of reduction in the proof stress of the object to be processed. Utilizing the fact that the load of the ultrasonic oscillator varies due to changes in the vibration resistance, the load signal of the ultrasonic oscillator can be employed as an index corresponding to the degree of reduction in yield strength of the workpiece. By adopting the load signal of the ultrasonic oscillator as an index corresponding to the degree of reduction in yield strength of the workpiece, as can be seen from the embodiments described later, stable cutting can be performed with simple equipment. control becomes feasible.

A second aspect of the present invention is the synthetic resin cutting method according to the first aspect, wherein a target range of a predetermined width is set for the load signal of the ultrasonic oscillator, and the load signal remains within the target range. Control is performed to change the relative feed amount in the cutting direction of the cutting edge with respect to the object to be processed.

According to the cutting method of this aspect, as will be understood from the embodiments described later, only by setting the target range width for the load signal of the ultrasonic oscillator, the relative feed speed between the workpiece and the cutting edge and the workpiece can be adjusted. It is possible to stably perform the intended cutting process without being greatly affected by the state of the workpiece.

In a third aspect of the present invention, when cutting an object made of synthetic resin, the cutting edge of a processing tool is pressed against the object to apply ultrasonic vibration to the processing tool, and the object to be processed is Cutting of a synthetic resin in which the workpiece is a thermosetting resin by controlling the relative feed in the cutting direction of the cutting edge with respect to the workpiece using the degree of reduction in yield strength of the workpiece as an index. A method is characterized.

According to the cutting method of this aspect, even when the object to be processed is a thermosetting resin, the region where the pressing portion of the cutting blade is ultrasonically heated is limited, and the cutting blade is fed at a low feed speed. By repeating the decrease in yield strength due to local heating of the workpiece in the process and the rapid cutting of the workpiece at a high feed rate, it is possible to efficiently avoid damage due to excessive heating of the workpiece. It is possible to realize a cutting process with a high precision. When the synthetic resin is a fiber-reinforced resin in combination with the second mode, the base material of the fiber-reinforced resin is a thermosetting resin.

In a fourth aspect of the present invention, when cutting an object made of synthetic resin, the cutting edge of a processing tool is pressed against the object to apply ultrasonic vibration to the processing tool, and the object to be processed is The relative feed of the cutting blade with respect to the object in the cutting direction is speed-controlled using the degree of reduction in proof stress of the object as an index, and after cutting the object, the cutting edge is removed from the object . A method of cutting a synthetic resin is characterized in that when the working tool is pulled out, the output of the ultrasonic oscillator that gives the ultrasonic vibration is made smaller than that during cutting.

According to the cutting method of this aspect, when the working tool is pulled out from the object heated by ultrasonic waves, the output of the ultrasonic oscillator is made smaller than that during cutting, so that the working tool can be removed from the object. In addition, it is possible to suppress the problem that the object to be processed is pulled up in the extraction direction together with the processing tool and remains on the surface of the object to be processed in a raised manner. In this aspect, "after cutting" includes "interruption of cutting" as well as "completion of cutting".

A fifth aspect of the present invention is the synthetic resin cutting method according to the fourth aspect, wherein after cutting the object to be processed and before pulling out the machining tool from the object to be processed, After the ultrasonic vibration is stopped, the ultrasonic vibration is restarted, and the withdrawal speed of the working tool after cutting is made higher than the advancing speed of the working tool during cutting.

According to the cutting method of this aspect, by temporarily stopping the ultrasonic vibration of the processing tool immediately before the processing tool is pulled out, excessive softening of the processing object is suppressed, and the processing object that is pulled up in the pulling direction together with the processing tool is removed. can be suppressed. By combining this aspect with the fourth aspect, it is possible to more effectively prevent the workpiece from being pulled up together with the machining tool in the pull-out direction.
A sixth aspect of the present invention is the synthetic resin cutting method according to any one of the first to fifth aspects, wherein the synthetic resin is a fiber-reinforced resin.
According to the cutting method of this embodiment, the cutting blade is constantly ultrasonically vibrated, so that the fiber-reinforced resin can be cut in the presence of the resin whose yield strength has been reduced by heating, resulting in delamination (interlayer peeling) and fluffing. It is possible to suppress the generation of burrs (fine hair-like particles formed by rubbing the surface) and burrs (protrusions generated when processing materials), and to avoid the generation of cutting waste as much as possible.
A seventh aspect of the present invention is the synthetic resin cutting method according to the sixth aspect, wherein the reinforcing fibers of the object to be processed are carbon fibers.
According to the cutting method of this aspect, the cutting edge is efficiently pressed against the carbon fiber by reducing the proof stress of the base material due to the ultrasonic vibration, and both sides of the pressing portion of the cutting edge on the carbon fiber are Since the carbon fiber is fixedly supported by the base material whose yield strength is not reduced and tension is applied to the carbon fiber, the cutting action of the cutting blade that is ultrasonically excited can be efficiently exerted on the carbon fiber.
An eighth aspect of the present invention is the synthetic resin cutting method according to any one of the first to seventh aspects, wherein the working tool is a cylindrical punching tool having the cutting edge on the peripheral edge of the tip. , the ultrasonic vibration is applied in at least one of the axial direction and the circumferential direction of the punching tool.
According to the cutting method of this aspect, the secondary processing of drilling a synthetic resin can be realized. In general, the feeding direction of the cutting blade in punching is the thickness direction of the object to be processed. In the case of the fiber-reinforced resin used as the fiber, the cutting direction, which is the feed direction of the cutting blade, is always substantially orthogonal to the running direction of the reinforcing fiber parallel to the surface of the object to be processed, and the reinforcing fiber A better cut surface can be stably realized for
A ninth aspect of the present invention is the synthetic resin cutting method according to any one of the first to seventh aspects, wherein the processing tool is a plate-shaped cutting tool having the cutting edge forward in the feeding direction. The ultrasonic vibration is applied in the direction along the plate surface of the cutting tool.
According to the cutting method of this aspect, for example, a knife-like processing tool can be employed as the plate-shaped cutting tool, and ultrasonic vibration can be efficiently applied to the processing object, and the processing tool can be used as the processing object. It is also possible to pierce through an object, and it is possible to cut the object to be processed starting from the pierced point even from an intermediate portion of the object to be processed. In addition to perforating, it is also possible to cut an object to be processed in a straight line or a curved line. It should be noted that this aspect can be applied regardless of the purpose, process, type, etc. of the processing, such as trimming or finishing of the outer shape of the resin molded product.

A tenth aspect of the present invention is an apparatus for cutting a workpiece made of synthetic resin, comprising: (a) an ultrasonic oscillator that generates ultrasonic vibration; and (b) a cutting blade that cuts the workpiece. and (c) pressing the cutting edge of the machining tool against the workpiece to perform the machining (d) a feed mechanism for moving a tool relative to the workpiece in the cutting direction; a feed control mechanism for speed control using the degree of reduction as an index; A synthetic resin cutting apparatus characterized by comprising a part .

The cutting apparatus constructed according to the present invention can perform the cutting of synthetic resin according to the method of the present invention as described above.

Further, according to the cutting apparatus of this aspect, when the working tool is pulled out from the object to be processed, the output of the ultrasonic oscillator is made smaller than that in cutting, so that the working tool can be smoothly pulled out from the object to be processed. In addition, problems such as the workpiece being lifted in the drawing direction together with the machining tool and remaining on the surface of the workpiece in a raised manner can be suppressed.

An eleventh aspect of the present invention is an apparatus for cutting a workpiece made of synthetic resin, comprising: (a) an ultrasonic oscillator for generating ultrasonic vibration; and (b) a cutter for cutting the workpiece. (c) pressing the cutting edge of the machining tool against the object to be processed; (d) a feed mechanism for moving a machining tool relative to the workpiece in the cutting direction; a feed control mechanism for speed control using the degree of reduction in yield strength as an index; A pull-out stop control unit for stopping ultrasonic vibration and then restarting ultrasonic vibration; and a pull- out control unit for cutting synthetic resin .

According to the cutting apparatus of this aspect, by stopping the ultrasonic excitation of the machining tool before pulling out the machining tool from the machining object, excessive softening of the machining object can be avoided. Therefore, while applying energy by ultrasonic vibration to the extent that it is possible to pull out the processing tool from the processing object, it is pulled up by the processing tool and remains on the surface of the processing object in a raised manner. problems can also be suppressed.
A twelfth aspect of the present invention is an apparatus for cutting a workpiece made of synthetic resin, comprising: (a) an ultrasonic oscillator for generating ultrasonic vibration; and (b) cutting the workpiece and (c) pressing the cutting edge of the machining tool against the object to be processed. (d) a feed mechanism for moving the machining tool relative to the object in the cutting direction; a feed control mechanism for speed control using the degree of reduction in yield strength of the object as an index; A synthetic resin cutting apparatus characterized by utilizing a load signal of an ultrasonic oscillator that provides a .
A thirteenth aspect of the present invention is the synthetic resin cutting apparatus according to any one of the tenth to twelfth aspects, wherein the synthetic resin is a fiber-reinforced resin.
According to the cutting apparatus of this aspect, even fiber-reinforced resin, which is difficult to cut, can be cut without greatly roughening the cut surface and while suppressing the generation of chips.

According to the present invention, the feed speed (feed amount) of the cutting blade to the object to be processed is appropriately controlled, and damage to the cutting blade and slowing of the processing speed can be prevented.

In addition, in the second aspect and the thirteenth aspect, in which the object to be processed is made of fiber-reinforced resin, it is possible to avoid the generation of chips generated by a conventional rotary tool and the like, and to prevent delamination and fuzzing. It is possible to cut the fiber reinforced resin with a good cut surface in which the generation is suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an apparatus structural diagram showing a first embodiment of a cutting apparatus constructed according to the present invention for carrying out the method of the present invention; FIG. 2 is an explanatory diagram showing an enlarged cutting edge portion of a drilling tool as a processing tool attached to the cutting apparatus of FIG. 1; FIG. 2 is a model explanatory diagram for explaining an example of a control mode according to the present invention of a feed mechanism in the cutting apparatus of FIG. 1; FIG. 2 is a graph showing changes in load over time as one of the results of an experiment (Example 1) in which holes were drilled in a CFRP plate of a PC base material using the cutting apparatus of FIG. 1. FIG. Explanatory photographs showing the state of the machined surface of the object to be machined obtained in the experiment (Example 1) shown in FIG. SEM photograph of the inner peripheral surface. 5 is a graph showing the results of actually measuring the time required for drilling by varying the pressing speed between the cutting edge and the workpiece during the experiment (Example 1) shown in FIG. 4 . FIG. 2 is a graph showing changes in load over time as one of measured data obtained from an experiment (Example 2) of drilling holes in a CFRP plate of an EP base material using the cutting apparatus of FIG. 1. FIG. Explanatory photographs showing the state of the machined surface of the object to be machined obtained in the experiment (Example 2) shown in FIG. ) is a plane photograph of the exit side of the cutting edge, and (b) is a SEM photograph of the inner peripheral surface of the hole. Explanatory drawing which expands and shows the part of the cutting edge of the drilling tool which took one example of measures against a cut piece. FIG. 2 is an apparatus structural diagram showing a second embodiment of a cutting apparatus constructed according to the present invention for carrying out the method of the present invention. 11A and 11B are explanatory diagrams for explaining a state in which an object to be processed is cut by a cutting tool in the cutting apparatus shown in FIG. The top view which shows a specific example of a cutting tool, (c) is a top view which shows another specific example of a cutting tool. FIG. 11 is a partial cross-sectional view showing another aspect of a cutting tool that can be attached to the cutting device shown in FIG. 10; FIG. 11 is an explanatory diagram for explaining a state in which an object to be processed is cut using the cutting apparatus shown in FIG. 1 to which the cutting tool of FIG. 11 is attached; Using the cutting apparatus shown in FIG. 1 equipped with the cutting tool shown in FIG. 11, load Graph showing changes over time. Using the cutting apparatus shown in FIG. 1 equipped with the cutting tool shown in FIG. 11, load Graph showing changes over time. The inner peripheral surface of the hole when the cutting tool shown in FIG. SEM photographs of (a) when the output of the ultrasonic oscillator is 150 W, (b) when the output of the ultrasonic oscillator is 200 W, and (c) when the output of the ultrasonic oscillator is 300 W case. When a PC plate material is perforated using the cutting apparatus shown in FIG. SEM photograph of the inner peripheral surface of (a) when the output of the ultrasonic oscillator is 150 W, (b) when the output of the ultrasonic oscillator is 200 W, and (c) the output of the ultrasonic oscillator is 300W.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, FIG. 1 shows, as a first embodiment of a cutting apparatus constructed according to the present invention for carrying out the method of the present invention, a plate-shaped fiber-reinforced resin as an object to be processed, and rivets and bolt insertion holes. The structure of the cutting device 10 for drilling a circular through-hole, which is assumed to be used as, etc., is schematically shown. The cutting apparatus 10 includes a work table 16 that is driven up and down with respect to a base 12 by an electric cylinder 14 as a feed mechanism. Above the work table 16, a vibrator 18 is fixedly supported by a support arm 22 of a column 20 erected on the base 12. A cutting tool 26 is attached as a tool. The vibrator 18 is vibrated by the ultrasonic oscillator 28, and the cutting tool 26 is ultrasonically vibrated.

In this embodiment, as the cutting tool 26, as shown in FIG. 2, a punching tool having a cylindrical punching blade protruding toward the work table 16 below is adopted. An annular cutting edge 30 having a sharp cross section is set on the edge of the tip of the punching edge. In addition, a discharge window for discharging the punched piece is provided above the cylindrical punching blade so as to open to the side, so that continuous punching can be realized.

Then, the workpiece 32 is fixedly placed on the work table 16, the electric cylinder 14 is driven upward, and the workpiece 32 is moved closer to the cutting tool 26 excited by the ultrasonic wave. , the cutting edge 30 is pressed from the upper surface of the workpiece 32 to perform the drilling process. For the purpose of protecting the cutting edge 30 that has penetrated the object 32 during the drilling process, it is desirable that the object 32 be fixed on the worktable 16 with an appropriate jig via an auxiliary plate 34. .

In such a cutting apparatus 10, when drilling the workpiece 32, the feeding speed of the workpiece 32 in the drilling direction with respect to the cutting edge 30 by the electric cylinder 14 is determined by the degree of reduction in the yield strength of the workpiece 32. is controlled in such a manner that it repeats increase and decrease using as an index. That is, the object 32 to be processed generates frictional heat when the ultrasonically excited cutting edge 30 is pressed against it. , the cutting edge 30 cuts the region where the proof stress is lowered by increasing the feed rate after reaching the temperature at which the proof stress of the workpiece 32 is lowered. In addition, since the region where the proof stress of the workpiece 32 due to the frictional heat of the cutting blade 30 is reduced is limited not only in the planar direction but also in the depth direction, the cutting edge of the cutting blade 30 has a proof stress in the depth direction. When it reaches the region where it has not decreased, the feed rate is reduced again, the workpiece 32 is heated by the cutting edge 30 with ultrasonic waves, and after the yield strength of the workpiece 32 has decreased, the feed rate is increased and cut. control to repeat the process.

The increase and decrease in the feed speed of the workpiece 32 with respect to the cutting edge 30 is not limited in terms of the amount of increase and decrease and the mode of increase and decrease. It can be set as appropriate according to, for example. In principle, the feed speed to be increased or decreased is not set to minus (backward), but 0 (stop) can be adopted at low speed. Furthermore, the drive control device 36 as a feed control mechanism for the electric cylinder 14 that drives the work table 16 up and down is preferably one that can set the upper limit of the movement speed, but is not particularly limited. It suffices if the feed speed of the object 32 in the drilling direction with respect to the cutting edge 30 can be controlled using the degree of decrease in the proof stress of the object 32 as an index.

In this embodiment, as will be described later, the moving speed in the cutting direction is controlled in such a manner that it repeats increase and decrease within a substantially constant range, using the degree of decrease in yield strength of the workpiece 32 as an index. Here, for example, the load signal of the ultrasonic oscillator 28 is adopted as an index capable of specifying the degree of reduction in the yield strength of the workpiece 32, and the load signal S is transmitted from the ultrasonic oscillator 28 to the drive control device 36. An automatic control loop can be constructed. In the automatic control loop, the load signal may be grasped continuously at all times and controlled to be within a certain range. Alternatively, the load signal may be received at regular time intervals such as every 0.5 seconds and controlled to be within a certain range.

As a specific mode of control of the feed speed, for example, the output level of the ultrasonic oscillator 28, in other words, the magnitude of the load on the vibrator 18, is set to a target range of a predetermined width so as to stay within the target range. , feedback control of the moving speed of the electric cylinder 14 by the drive control device 36 can be mentioned. That is, the vibrating state of the vibrator 18 changes depending on the load applied to the cutting tool 26 having the cutting edge 30, vibrating well with a small load, but hardly vibrating with a large load. The ultrasonic oscillator 28 of this embodiment is designed to stop when an excessive load equal to or greater than a specific threshold is applied.

Therefore, for example, as illustrated in FIG. 3, for the ultrasonic oscillator, a control reference value of a specific percentage (for example, 70%) is set with respect to the threshold value, and for example, a range of ±10% above and below is set. is provided to decelerate (including stop) the upward drive of the electric cylinder 14 when the load becomes +10% of the control reference value, and set the electric cylinder 14 in advance when the load becomes -10% of the control reference value By performing control to drive upward at the set speed, the feed speed (feed amount) of the workpiece 32 in the drilling direction with respect to the cutting edge 30 is repeatedly increased and decreased using the degree of reduction in the proof stress of the workpiece 32 as an index. Control can be implemented. In FIG. 3, the horizontal axis represents the feed amount of the workpiece 32 by the electric cylinder 14, and the feed speed is grasped by the slope (differential value) of the graph.

Using the cutting apparatus 10 as described above, the result of drilling a fiber reinforced resin whose base material is a thermoplastic resin is referred to as Example 1, and the fiber reinforced resin whose base material is a thermosetting resin The results of drilling the resin are shown below as Example 2.

SH-3510 (trade name) and SF-3110 (trade name) manufactured by SONOTEC Co., Ltd. were used as the ultrasonic oscillator 28, vibrator 18 and horn 24 in the cutting apparatus 10, respectively. The tool attached to the tip of the horn 24 was made of SK95 and had an outer diameter (Do) of 6.5 mm, an inner diameter (Di) of 5.5 mm, and an edge angle (θ) of 15°. Also, as the electric cylinder 14 and the drive control device 36 for driving the work table 16 up and down, EC-R7 (trade name) manufactured by IAI Co., Ltd. is adopted, and the driving force is applied to the work table 16 via a load cell for detecting load. affected.

Further, as the processing object 32 made of the thermoplastic fiber-reinforced resin of Example 1, a flat-plate-shaped molding with a plate thickness of 2 mm was obtained by impregnating plain-woven carbon fibers with polycarbonate resin (PC) as a base material and curing. adopted the product. On the other hand, as the processing object 32 made of the thermosetting fiber-reinforced resin of Example 2, a prepreg obtained by impregnating the same plain-woven carbon fiber as in Example 1 with an epoxy resin (EP) as a base material is autoclave-molded. A plate-shaped molded article having a plate thickness of 2 mm was adopted.

[Example 1]
The control reference value of the ultrasonic oscillator 28 is set to 80% of the maximum output level of the ultrasonic oscillator 28 for the fiber reinforced composite resin using the thermoplastic resin as the base material as the processing object 32, and ±5% up and down. , the electric cylinder 14 is stopped when the load reaches +5% of the control reference value, and the electric cylinder 14 is raised when the load reaches -5% of the control reference value: 8.75 mm/ Drilling was performed by driving with the setting of s. FIG. 4 shows the time variation of the load measured by the load cell during such processing.

Since the set speed of the electric cylinder 14 is 8.75 mm/s, it should take about 0.2 seconds to punch a plate having a thickness of 2 mm, but it actually took 3.4 seconds. As shown in FIG. 4, the electric cylinder 14 rises and the workpiece 32 comes into contact with the cutting edge 30, and the load increases between 0 and 1 s. When the cutting blade 30 is not pushed into the object 32, frictional heat is exerted on the object 32 by ultrasonic vibration of the cutting blade 30, and the proof stress of the resin begins to decrease. Cutting by pressing is started, and thereafter, as described with reference to FIG. 3, the electric cylinder 14 is repeatedly raised and stopped in accordance with the degree of reduction in the proof stress of the resin, and the cutting blade 30 cuts the workpiece 32. By proceeding.

According to the present Example 1, it was possible to perform the drilling process on the workpiece 32 in a good condition. FIG. 5(a) shows a plane photograph of the drilled portion of the obtained workpiece 32 as viewed from the entrance side of the cutting edge 30, and a scanning electron microscope shows an enlarged inner peripheral surface of the drilled hole. A (SEM) photograph is shown in FIG. From FIG. 5(a), it can be seen that the surface properties are good without occurrence of defects such as burning, delamination, fluffing, and burrs. In addition, from FIG. 5(b), the carbon fiber runs perpendicular to the drilling direction (vertical direction in the figure), and the entire surface is covered with molten resin. It can be seen that the thermoplastic resin is cut by the cutting edge 30 .

Furthermore, for the purpose of examining the stability of machining and machining efficiency, etc., in the first embodiment, the pressing speed (set speed of the electric cylinder 14) between the cutting blade 30 and the workpiece 32 is varied to perform drilling. The required time was actually measured. The results are shown in the graph of FIG.

Specifically, for four types of control reference values of the ultrasonic oscillator 28 of 20%, 40%, 60%, and 80%, a range of ±5% is provided above and below each. When the load became +5% of the control reference value, the electric cylinder 14 was stopped, and when the load became -5% of the control reference value, the electric cylinder 14 was driven upward. In addition, the set speed of the electric cylinder 14 was set to nine different values within the range of 1.75 mm/s to 15.75 mm/s. FIG. 6 shows the results of measuring the time required for drilling under each setting condition.

As shown in FIG. 6, even if the pressing speed of the cutting edge 30 against the workpiece 32 by the electric cylinder 14 is increased, the load applied to the vibrator 18 is increased, and the ultrasonic oscillator 28 is immediately activated. Since the upward drive of the electric cylinder 14 stopped when the control reference value was reached, the machining time was hardly shortened. On the other hand, when the control reference value of the ultrasonic oscillator 28 was increased, the machining time was shortened. The reason for this is that a large load can be applied to the vibrator 18 by increasing the allowable range of the load, and the amount of frictional heat generated in the workpiece 32 by the ultrasonic vibration of the cutting edge 30 also increases. It is considered that this is because the time required for the decrease is shortened.

Of course, even under the various conditions described above, the drilling performed on the workpiece 32 was good, although variations occurred in the machining time. Therefore, regardless of the set speed of the electric cylinder 14, it can be seen that the intended drilling can be stably performed.

[Example 2]
As in the first embodiment, the control reference value of the ultrasonic oscillator 28 is set to 80% for the fiber-reinforced composite resin using the thermosetting resin as the base material, and the upper and lower ranges of ±5% are provided. When the load becomes +5% of the control reference value, the electric cylinder 14 is stopped, and when the load becomes -5% of the control reference value, the electric cylinder 14 is driven at a rising speed of 7.00 mm / s. I did the drilling. FIG. 7 shows the time change of the load measured by the load cell during such processing.

As in the first embodiment, even if the electric cylinder 14 rises and the workpiece 32 contacts and is pressed against the cutting edge 30 and the load increases, the cutting edge will be inside the workpiece 32 at the initial stage. Although the cutting blade 30 was not pushed in, frictional heat was exerted on the workpiece 32 by the ultrasonic vibration of the cutting blade 30, and the proof stress of the resin began to decrease. After that, as described with reference to FIG. 3, the electric cylinder 14 was repeatedly raised and stopped in accordance with the degree of decrease in the proof stress of the resin, and the cutting of the workpiece 32 by the cutting blade 30 proceeded.

The epoxy resin, which is the base material of the embodiment, is a thermosetting resin and has high heat resistance, and the temperature at which the yield strength is lowered is higher than that of the first embodiment. Although it took a long time, the hole was finally punched out, and the target drilling process was completed.

FIG. 8(a-1) shows a plan view of the hole-forming portion of the workpiece 32 obtained in Example 2, viewed from the entrance side of the cutting edge 30, and the image from the exit side of the cutting edge 30. A plane photograph is shown in FIG. 8(a-2). A scanning electron microscope (SEM) photograph showing an enlarged inner peripheral surface of the drilled hole is shown in FIG. 8(b).

From FIGS. 8A-1 and 8A-2, it can be seen that the surface properties are good without occurrence of defects such as burning, delamination, and fluffing. Also, from (b), it can be seen that the bundle of carbon fibers running perpendicular to the drilling direction (vertical direction in the figure) is brittlely broken. Also, it can be seen that the resin impregnated between the carbon fibers is ductilely punched out due to the reduction in yield strength due to frictional heat. For this reason, even when a fiber reinforced resin having a thermosetting resin as a base material is used as a processing object, according to the present invention, after ultrasonic heating to a temperature at which the proof stress of the base material decreases, In addition, by performing cutting only on areas where the yield strength has decreased due to local heating by ultrasonic waves, it is possible to cut with good surface properties without the occurrence of problems such as burning, delamination, fluff, and burrs. I can understand something.

Note that the cutting tool 26 is not limited to a cylindrical shape, but may have various shapes such as a polygonal prism shape and a flat blade shape depending on the required cutting shape. On the other hand, as explained above, almost no cutting waste means that there is a high possibility that the cut piece will remain in a cutting tool such as a cylindrical cutting tool. As a measure for mass production, for example, an air hole 31 is provided in a part of the cutting tool as shown in FIG. A mechanism can be employed to remove chips and shavings by blowing them out of an opening at the tip of the cutting edge. Furthermore, even during the cutting process, by allowing a small amount of air to flow into the air hole 31, it may be possible to delay the processing time, but it can be used to improve the smoothness of the cut surface.

Next, FIG. 10 shows a cutting device 40 as a second embodiment of the cutting device constructed according to the present invention for carrying out the method of the present invention. In the cutting device 40 of the present embodiment, the members and portions substantially identical to those of the cutting device 10 of the first embodiment are denoted by the same reference numerals as those of the first embodiment. A more detailed description will be omitted.

In this embodiment, the shape of the cutting tool is first different from that of the first embodiment. As shown in FIGS. 11(a) and 11(b), the cutting tool of this embodiment employs a longitudinal plate-like or substantially plate-like cutter knife 42 extending in the vertical direction as a whole. The cutter knife 42 has a cutting edge 44 on the front edge portion in the cutting direction. A single-edged cutting edge 44 as shown in FIG. 11(b) or a double-edged cutting edge 48 as shown in FIG. 11(c) may be used. In any case, the cutter knife 42 has a sharp cutting edge that continuously extends linearly in the vertical direction at the front end in the cutting direction. In FIGS. 11 and 12, the cutting edges 44 and 52 are shown in gray.

Further, in the cutting apparatus 40 of the present embodiment, the work table 16 is provided with the chuck 45 , and the outer peripheral portion of the workpiece 32 can be gripped and fixed on the work table 16 by the chuck 45 . It is desirable that the chuck 45 fixes the workpiece 32 to the work table 16 not only in the plane direction perpendicular to the plane of FIG. 10 but also in the vertical direction perpendicular thereto.

Further, in the above-described embodiment, the cutting direction for the workpiece 32 is the vertical direction. ) can be vertically pressed against the workpiece 32, but in this embodiment, the cutting direction with respect to the workpiece 32 is the horizontal direction, and the orthogonal three-axis directions of X, Y, and Z The movement of the object 32 can be controlled by , and the rotation of the cutter knife 42 with respect to the object 32 can be controlled around the Z-axis in the vertical direction.

Specifically, for example, by driving the electric cylinder 14z, the worktable 16 holding the workpiece 32 can be controlled to move in the vertical direction (Z-axis direction), and the horizontal electric cylinders 14x and 14y can be controlled. By driving, the work table 16 holding the workpiece 32 can be controlled to move in two horizontal orthogonal directions (front, back, left, and right directions) in the X-axis and Y-axis directions. A horn 24 and a vibrator 18 for chucking and supporting the cutter knife 42 are rotatably supported around a vertical axis (Z-axis). The orientation of the cutting edge 44 of the cutter knife 42 can be changed by controllable orientation around the Z axis.

A specific mechanism for realizing relative movement between the cutter knife 42 and the workpiece 32 in the directions of the three orthogonal axes X, Y, and Z and rotation around the Z axis is not limited. For example, the movement in the orthogonal three-axis directions may be realized on the cutting tool 26 side, or the rotation around the Z-axis may be realized on the work table 16 side. In addition to 4-degree-of-freedom control consisting of movement in the directions of the three orthogonal axes X, Y, and Z and rotation around the Z-axis, 1-degree-of-freedom control consisting of movement in the X direction is possible if only linear cutting is possible. It may be control, and in the case of cutting a three-dimensional shape, control with five or more degrees of freedom including tilting may be adopted. Also, each of these movements and rotations is desirably implemented by, for example, a programmable numerical control mechanism.

In the cutting device 40 of the present embodiment having such a structure, the vibrator 18 is vibrated by the ultrasonic oscillator 28, for example, so that the cutter knife 42 moves in the direction along the plate surface of the cutter knife 42, That is, in this embodiment, ultrasonic vibrations are applied in a direction parallel to the plane of FIG. 11 (for example, vertical, horizontal, or oblique directions in FIG. 11). Then, the cutter knife 42 and the workpiece 32 are relatively moved, and the cutting edge of the cutting edge 44 of the cutter knife 42 subjected to ultrasonic vibration is pressed against the end of the workpiece 32 to cut. process.

In this cutting process, as in the first embodiment, the proof stress of the workpiece 32 is reduced by heating with ultrasonic waves, and each time, the workpiece 32 is moved in the cutting direction by the sharpened cutting edge 44. It progresses by being sent and disconnected. That is, in the present embodiment, the cutting edge 44 is provided in front of the cutter knife 42 in the cutting direction, and the cutter knife 42 is fed to the workpiece 32 in the cutting direction to cut the workpiece 32. can be

Note that FIG. 11B shows a state in which the object 32 is cut by the cutter knife 42 from above. It is desirable that the upper part is the product side and the lower part than the cutter knife 42 is discarded. That is, in the single-edged cutter knife 42, the upper surface side 32a in FIG. 11(b) can have a better cut edge than the lower surface side 32b, which is the blade surface side.

Also, like a cutter knife 46 shown in FIG. 11(c), a double-edged cutting edge 48 can have a smaller cutting edge angle (intersecting angle between both surfaces) at the tip compared to a single-edged cutting edge 44. For example, it becomes easier to cut soft synthetic resin materials more efficiently.

Furthermore, the cutting tool employed in this embodiment has a tapered lower end in a side view, such as a cutter knife 50 shown in FIG. Alternatively, the cutting edge 52 may have an acute tip angle α.

When the cutting edge 52 having the tip angle α is used, for example, by pressing the sharp lower end of the ultrasonically excited cutter knife 50 against the workpiece 32 from above, the workpiece 32 can be penetrated. . Thereafter, by moving the cutter knife 50 in the horizontal direction with respect to the object 32 while applying ultrasonic vibrations, the object 32 can be cut. This eliminates the need to start cutting from the edge portion of the object 32 to be processed. For example, it becomes possible to perform a hole punching process so as to hollow out the central portion of the plate surface of the object 32 to be processed. The lower end of the cutting edge 52 may be rounded or chamfered, as long as it is substantially sharp.

In the cutter knife 50 shown in FIG. 12, instead of or in addition to the inclined portion at the lower end in FIG. 12, the left edge portion in FIG. A vertically extending cutting edge (such as the extending cutting edge 44) may be provided. In such a case, by sending the cutter knife 50 to the left in FIG. 12 with respect to the workpiece 32, instead of or in addition to the right in FIG. can be

With the cutting device 40 of the present embodiment having the structure as described above, the workpiece 32 can be cut linearly (including straight lines and curved lines) in addition to the drilling process of the first embodiment. It is possible to When cutting in a curved line, the cutter knives 42 and 50 and the workpiece 32 are relatively rotated around the Z-axis so that the cutting edge of the cutting edge 44 faces forward in the cutting direction. It is desirable to

In particular, compared with the cutter knife 42 shown in FIG. 11, the cutter knife 50 shown in FIG. ) can be reduced. Therefore, when cutting the workpiece 32 in a curved shape, the cutter knife 50 shown in FIG. 12 can draw a cutting line with a smaller radius of curvature. In addition, since the cutting surface of the object 32 is inclined, a large contact (abutting) surface between the object 32 and the cutting edge of the cutting edge 44 can be ensured, enabling efficient cutting. Become.

On the other hand, in the cutter knife 42 shown in FIG. 11, in which the width of the cutting edge can be increased in the portion that penetrates the workpiece 32, damage to the cutter knife is effectively prevented, and ultrasonic vibration can be applied with a large power. is also possible. In addition, since the cutting edge 44 can be set long in the vertical direction, it can be easily applied to a thick workpiece 32, and by sequentially moving the portion that abuts on the workpiece 32, the cutter knife 42 can be vertically moved. It is also possible to efficiently utilize the entire cutting edge 44 provided long in the length direction.

Further, for example, when the cutter knives 42 and 50 are vertically vibrated with ultrasonic waves, the cutter knife 50 shown in FIG. The cutter knife 42 to be cut is in contact with the cut surface of the workpiece 32 while the ultrasonic vibration is being performed. Therefore, when the cutter knives 42 and 50 are ultrasonically vibrated in the vertical direction, the cutter knife 42 shown in FIG. 11 can heat the workpiece 32 more efficiently.

Of course, by vibrating the cutter knife 50 in a direction substantially parallel to the inclined cutting edge of the cutting blade 52 , it is possible to improve the contact state of the cutting edge of the cutter knife 50 with the workpiece 32 . Further, in addition to or instead of the vertical direction, ultrasonic vibration may be applied in the horizontal direction (cutting direction) for any of the cutter knives 42 and 50 .

[Example 3]
It was confirmed that the object 32 can be cut linearly using the cutter knife 42 described in the second embodiment. As the cutting device and the working tool, the cutting device 10 and the cutting tool 26 described in the first embodiment are adopted for reasons such as convenience. That is, in the cutting tool 26 shown in FIG. 2, the cutter knife 42 shown in FIGS. The cutting tool 26 described in the embodiment was used in a mode of cutting the workpiece 32 linearly instead of drilling. In other words, if only the portion of the cylindrical cutting tool 26 that touches and cuts the workpiece 32 is taken out, the plate extends substantially linearly in the thickness direction of the workpiece 32 although somewhat curved. It can be grasped as a cutting tool having a pair of plate-shaped cutting edges 53 (a pair of plate-shaped cutting edges located opposite each other in the radial direction).

Specifically, as shown in FIG. 13, a flat plate-shaped workpiece 32 is fixedly arranged in an upright position on the work table 16 of the cutting device 10, and a cutting tool 26 ( The cutter knife 42) was pressed downward from above, which is the cutting direction, against the upper edge of the workpiece 32 while being ultrasonically excited in the rotation direction around the vertical central axis (Z-axis). . Substantially, the workpiece 32 is placed horizontally on the work table 16 of the cutting apparatus 10 .

In Example 3, as the object 32 to be processed, a flat-plate-shaped molded product with a thickness of 2 mm, which is obtained by impregnating plain-woven carbon fiber with polycarbonate resin (PC) as a base material and curing, is adopted. . Also, using an ultrasonic oscillator 28 with a rated output of 500 W, the control reference value of the ultrasonic oscillator 28 is set to 450 W, which is 90% of the maximum output level, and a range of ± 5% is provided up and down to control the load. When the load reaches +5% of the reference value, the cutting blade 52 is stopped from advancing in the cutting direction with respect to the workpiece 32 by raising the electric cylinder 14 (advance speed: 0), while the load reaches -5% of the control reference value. Cutting was performed by driving the cutting tool 26 in the cutting direction at a forward speed of 1 mm/s. That is, the cutting tool 26 that has started advancing stops again when the load of the ultrasonic oscillator 28 reaches 95%, and advances again when the load reaches 85%. As a result, the cutting speed of the cutting tool 26 is actively and automatically controlled using the output level of the ultrasonic oscillator 28, which reflects the degree of proof stress of the workpiece 32, as an index. Good precision cutting can be performed with sufficient processing efficiency without requiring extensive experience and knowledge.

As a result, as shown in FIG. 13, two groove-shaped cut portions 54 extending downward from the upper end of the workpiece 32 were formed. That is, in the third embodiment, the cutting direction is downward, and the workpiece 32 can be cut linearly using a cutting tool corresponding to the single-edged cutter knife 42 shown in FIG. 11(a). could be confirmed. The cutting depth (cutting length) of the cutting portion 54 in this example was 4.6 mm. FIG. 14 shows changes over time in the contact load (processing load) of the cutter knife 42 with respect to the workpiece 32 in the cutting direction measured by the load cell during cutting in this embodiment.

From the graph shown in FIG. 14, the processing load was around 10N. However, in Example 3, since substantially the same cut portions 54 are formed at two locations under the same conditions, the processing load per location is considered to be about 5N. Also, the time from the start to the end of cutting was approximately 4.9 s. Therefore, the average cutting speed during the cutting process was approximately 0.9837 mm/s, which was not significantly different from the set advancing speed of the cutting tool 26 (1 mm/s). Partly because the contact area between the cutting tool 26 and the workpiece 32 was made sufficiently smaller than that in the drilling process of the first embodiment, it can be assumed that the forward stop of the tool was hardly controlled.

[Example 4]
A cutting test similar to that of Example 3 was performed by changing the base material of the workpiece 32 from polycarbonate resin to epoxy resin. The processing equipment including the ultrasonic oscillator and the test conditions are the same as those of the third embodiment.

As a result, even in Example 4 in which the thermosetting resin was used as the object to be processed, it was possible to perform a cutting process in which the cut portions 54, 54 as shown in FIG. 13 were formed. That is, even if the base material of the resin of the workpiece 32 is a thermosetting resin, it is confirmed that the workpiece 32 can be cut by using the same device and the same control as for the thermoplastic resin. I got it. The cutting depth (cutting length) of the cutting portion 54 in this example was 3.6 mm. FIG. 15 shows changes over time in the contact load (processing load) of the cutter knife 42 with respect to the workpiece 32 in the cutting direction measured by the load cell during cutting in this embodiment.

From the graph shown in FIG. 15, the processing load was around 40N. Therefore, as in Example 3, the processing load per one cut portion 54 is considered to be around 20N. Also, the time from the start to the end of cutting was approximately 3.9 seconds. Therefore, the average cutting speed during the cutting process was approximately 0.923 mm/s, lower than in Example 3 above. This is because the epoxy resin, which is the base material, has higher heat resistance than the polycarbonate resin, and the temperature at which the yield strength is lowered is higher than in Example 3, so the feed movement of the cutting tool 26 (cutter knife 42) cannot be controlled. It is considered to have entered more.

As is clear from the first to fourth embodiments described above, there is no significant adverse effect on the set value of the feed rate. At lower feed rates the cutting progresses more continuously than at higher feed rates and more intermittently at higher feed rates. As a result, the time required to complete the cutting process is not significantly affected. In the field, it is usually sufficient to set a feed rate that is larger than the predicted value to some extent, for example.

Moreover, the output set to the ultrasonic oscillator is not limited, and there is no significant adverse effect. That is, in the present invention, even if the output of the ultrasonic oscillator is small, the cutting edge is not forced to advance, and the cutting edge is prevented from advancing until the proof stress of the workpiece decreases, thereby avoiding damage. can be On the other hand, even if the output of the ultrasonic oscillator is large, the pressing time of the cutting edge required for the proof stress of the workpiece to decrease is shortened, and the cutting edge is rapidly advanced in the cutting direction. Resin deformation and the like can also be avoided.

By the way, in the drilling process as in the first embodiment and the straight or curved cutting process as in the second embodiment, cutting from the workpiece 32 is performed after finishing the machining (including interrupting the machining). It has been found that when the tool 26 is pulled out, problems in shape accuracy tend to occur in the workpiece 32 . Specifically, if the ultrasonically excited cutting tool 26 is simply pulled out as it is after the cutting process is completed, the heated and softened resin is pulled up together with the cutting tool 26, and the edge of the opening side of the machined hole is removed. Since the resin rises in the part and forms a bank, it is easy to cause problems in the processing accuracy of the product. In addition to the case where the processing tool is pulled out in the backward direction opposite to the forward direction during cutting, for example, the cutter knife 42, which is the processing tool, is advanced in the direction along the plate surface to perform the cutting. A similar problem occurs when the cutter knife 42 is later pulled out in a direction perpendicular to the plate surface.

By the way, when a machining tool similar to that of the first embodiment is employed, and when drilling by ultrasonic vibration is performed, the cutting tool 26 is pulled out from the workpiece 32 after machining while continuing the ultrasonic vibration. FIG. 16 is an enlarged photograph showing the state of the workpiece 32 obtained by . The workpiece 32 was a polycarbonate resin plate (2 mm thick, without fiber reinforcement), and the output of the ultrasonic transmitter was kept substantially constant from the start of the cutting process to the completion of pulling out the cutting tool 26. . Further, the withdrawal speed when the cutting tool 26 is withdrawn from the workpiece 32 after the cutting process is completed is set to approximately 2 mm/s. FIGS. 16A, 16B and 16C show the post-machining states of the workpiece obtained by setting the output of the ultrasonic oscillator 28 to 150 W, 200 W and 300 W, respectively.

On the other hand, if the ultrasonic vibration is stopped (the output of the ultrasonic oscillator 28 is set to approximately 0) before the cutting tool 26 is pulled out after forming the hole, the workpiece 32 will stick to the cutting tool 26 . , it was difficult to withdraw the cutting tool 26 .

The cutting devices 10 and 40 in the above-described embodiments have a pull-out control unit and/or a pull-out stop control that adjusts the output of the ultrasonic oscillator 28 and the pull-out speed of the cutting tool 26 according to the processing stage of the cutting tool 26. It is preferable to have a withdrawal ultrasonic wave control section 56 (see FIG. 10) as a section.

After the end of the cutting process, the withdrawal ultrasonic wave control unit 56 reduces the output of the ultrasonic oscillator 28 before withdrawing the cutting tool 26 to substantially stop the ultrasonic vibration of the cutting tool 26, and the cutting is started. Immediately before starting the withdrawal of the tool 26, the ultrasonic oscillator 28 is operated again to vibrate the cutting tool 26 with ultrasonic waves, and the withdrawal of the cutting tool 26 from the workpiece 32 is completed. has the function of

By substantially stopping the ultrasonic vibration before the cutting tool 26 is pulled out, it is possible to efficiently perform the cutting process with a sufficient power of the ultrasonic vibration, and the ultrasonic vibration during the cutting process is reduced. It is possible to avoid excessive softening or the like of the cutting tool 26 at the cutting portion of the workpiece 32 due to vibration when the cutting tool 26 is pulled out. As a result, even if the ultrasonic vibration is resumed when the cutting tool 26 is pulled out, the cutting tool 26 is not pressed against the workpiece 32 when the cutting tool 26 is pulled out. It is possible to effectively suppress deterioration in processing quality caused by the object 32 being excessively softened and pulled up by the processing tool.

In addition to or instead of functioning as the above-described withdrawal stop control unit, the withdrawal ultrasonic wave control unit 56 reduces the output of the ultrasonic oscillator 28 when the cutting tool 26 is withdrawn after the cutting process is finished. In a power-reduced state in which the power of ultrasonic vibration of the cutting tool 26 is at least smaller than that during cutting, the cutting tool 26 is ultrasonically vibrated, and the cutting tool 26 is pulled out from the workpiece 32. It may have a function as a pull-out control section to be executed. Furthermore, the withdrawal control section may be adapted to adjust the withdrawal speed of the cutting tool 26 after the cutting process. Therefore, the withdrawal speed of the cutting tool 26 after the cutting process is completed may be increased.

In the process of extracting the cutting tool 26, the power of the ultrasonic vibration is reduced compared to that in the cutting process, so that the cutting process can be efficiently performed with sufficient power of the ultrasonic vibration, and the cutting process can be performed. The cutting tool 26 can be pulled out while suppressing the softened state of the cutting portion of the object 32 compared to the cutting process. Therefore, the cutting tool 26 can be pulled out while avoiding sticking of the object to be processed by the ultrasonic vibration of the cutting tool 26 with low power, and the object 32 to be processed is excessively softened and pulled up by the processing tool. It is also possible to effectively suppress the deterioration of processing quality caused by being cut.

It should be noted that the stop time before the start of drawing by the drawing stop control unit and the power reduction during the drawing process by the drawing control unit depend on the material, size, and shape of the object to be processed, as well as the material and shape of the cutting tool 26. , characteristics, etc., so it is not limited. That is, the decrease in the output of the ultrasonic oscillator 28 depends on the material of the workpiece 32, the drawing distance, the drawing speed, etc., but can be set, for example, within the range of -5% to -90% during cutting. .

Incidentally, the cutting process was performed under the same conditions as the processing example shown in FIG. 16, and the ultrasonic vibration was temporarily stopped immediately after the cutting process (here, the output of the ultrasonic oscillator 28 was set to 0), and then the cutting was performed again. The cutting tool 26 was pulled upward from the workpiece while applying ultrasonic vibration to the tool 26 . Similar to the processing example shown in FIG. 16, the withdrawal speed of the cutting tool 26 is approximately 2 mm/s, and the output of the ultrasonic oscillator 28 during withdrawal is set to 150 W, 200 W, and 300 W, respectively. 17(a), (b), and (c) show the state of the object after processing.

Comparing (a), (b), and (c) of FIG. 17 with the corresponding (a), (b), and (c) of FIG. 16, the surface properties of the inner peripheral surface of the machined hole are good. , the bulge at the edge of the opening is also kept small.

In addition, in the order of (c) → (b) → (a) in FIG. It can also be seen that the dimensional accuracy of the cutting process can be improved by suppressing the power of the ultrasonic excitation of the cutting tool 26 to a low level.

In the above-described cutting test, when the ultrasonic vibration was restarted after the ultrasonic vibration was stopped after the cutting was completed, the cutting tool 26 was stuck to the cutting tool 26 due to the stop of the ultrasonic vibration. It was confirmed that the object 32 was peeled off at the moment the ultrasonic vibration was applied to the machining tool. From this, it is considered that, in the process of extracting the working tool, it is possible to rapidly withdraw the working tool from the object to be processed even with an output of about several percent during cutting. In addition, from the results of the cutting test as described above, adjusting the withdrawal speed of the processing tool also results in a decrease in the propagation of energy from the ultrasonically excited processing tool to the workpiece. This is considered to be effective in suppressing deterioration in processing quality caused by excessive softening or the like of the processing object 32 and being pulled up by the processing tool. Considering processing efficiency and the like, it is desirable to make the withdrawal speed of the processing tool after the cutting processing higher than at least the advancing speed of the processing tool during the cutting processing. In the embodiment shown in FIG. 17, the work table 16 is pulled out by free fall of its own weight by removing the force pushing up the work table 16 from below.

Moreover, the time for stopping the ultrasonic excitation (for example, setting the output of the ultrasonic oscillator 28 to 0) after cutting is not limited. Even if the time is extremely short, the effect of reducing the heating effect of the ultrasonic waves can be obtained. Furthermore, even after a long period of stoppage, the sticking between the cutting tool 26 and the workpiece 32 can be quickly eliminated by the subsequent ultrasonic excitation. In general, it can be set within a range of 0.5 to 5 seconds, for example, in consideration of work efficiency.

However, the withdrawal ultrasonic wave control unit 56 is based on a different idea from the idea of controlling the feed speed of the cutting tool 26 to the workpiece 32 using the degree of reduction in the proof stress of the workpiece 32 as an index. It is also adopted in the cutting devices 10 and 40 according to the first and second embodiments, or in the cutting device that does not employ speed control using the degree of reduction in the proof stress of the workpiece as an index. obtain.

Although specific embodiments of the present invention have been described in detail with examples, the present invention should not be construed as limited by these specific descriptions.

For example, in the first embodiment, the cutting edge 30 is pressed against the workpiece 32 by moving the workpiece 32 in the approaching direction with respect to the ultrasonically excited cutting edge 30 . However, it is also possible to control the movement of the cutting edge 30 in the approaching direction toward the workpiece 32, so that both the cutting edge 30 and the workpiece 32 are relatively moved in the approach/separation direction. Also good.

Moreover, the conditions for the ultrasonic vibration are not limited, and can be appropriately set according to the type, material, thickness of the workpiece, size of the tool, energy amount of the ultrasonic vibration, and the like. That is, although the ultrasonic wave applied to the transducer used in the above embodiment and Examples 1 to 4 was 20 to 22 kHz, it is not limited to this, and similar processing is possible as long as it is in the range of 15 to 100 kHz. becomes. Furthermore, the amplitude is preferably set within a range of, for example, 5 to 50 μm, and was approximately 15 μm in the above embodiment and Examples 1 to 4, but is not limited to this.

Furthermore, the specific mode of the cutting process is not limited, and in addition to the punching cutting process in the thickness direction of the object to be processed as described in Examples 1 and 2, for example, the second embodiment , and as described in Examples 3 and 4, the present invention can also be applied to linear cutting along the surface of an object to be processed.

In addition, although the vibration direction of the ultrasonic excitation exerted on the cutting blade is not particularly limited, in order to exert efficient shearing force and breaking force on the reinforcing fiber, the shearing direction by the cutting blade (the above-mentioned It is desirable to set the vibration direction of the ultrasonic excitation to the vertical direction in one embodiment) or the extending direction of the cutting edge of the cutting edge (the circumferential direction around the central axis of the cutting edge 30 in the first embodiment).

Furthermore, the material and shape of the fiber-reinforced resin to which the present invention is applied are not limited. For example, thermoplastic resins such as polypropylene, polyethylene, and polyetheretherketone, and thermosetting resins such as epoxy, polyimide, and unsaturated polyester resins can be used as synthetic resins for the base material. and a thermosetting resin can also be used. Also, as reinforcing fibers, any of carbon, aramid, glass, boron, and the like can be employed, and it is also possible to employ a combination of various reinforcing fibers. Furthermore, as the reinforcing fibers, fiber lengths such as short fibers, long fibers, and wire rods can be appropriately employed, and unidirectional fibers and cross fibers such as plain weave and twill weave can also be employed. Furthermore, the scope of application of the present invention is not limited by the molding method of the fiber-reinforced resin, which is the object to be processed. Of course, the synthetic resin to which the present invention is applied is not limited to fiber-reinforced resin, and may be made of, for example, a single resin material. In addition, the synthetic resin of the present invention is not to be interpreted in a narrow sense. It may have properties and may be construed as including natural resins.

Further, in the above-described embodiment, by using the output power level as a kind of load signal of the ultrasonic oscillator 28, the specific temperature and processing pressure at which the proof stress of the workpiece 32 decreases are grasped and set in advance. There is a technical advantage that simplification of control during cutting can be realized because there is no need to control the thickness.

This means that control is performed by detecting that the yield strength of the material (workpiece) has decreased at the point where the load has decreased. Here, as the load signal of the ultrasonic oscillator as an index relating to the degree of reduction in the yield strength of the object to be processed, the current or voltage supplied to the oscillator in the ultrasonic oscillator, the amount of power, or the electric power of the oscillator is used. It is also possible to employ a resistance value. In addition to the load signal of the ultrasonic oscillator, for example, the amplitude of the vibrator can also be used as an index relating to the degree of reduction in the proof stress of the object to be processed. This is because the vibration resistance of the vibrator increases when the proof stress of the object to be processed is not lowered, and the vibration resistance decreases according to the degree of the proof stress reduction. Even when the load signal of the ultrasonic oscillator, the vibration resistance of the vibrator, or the like is used as an index for control, a control range having a predetermined width is included as in the first to fourth embodiments described above. A similar effect can be obtained by controlling to be substantially constant. One of the major characteristics of the ultrasonic oscillator, which is controlled using load signals such as voltage, current, and power, and the amplitude of the oscillator, is that the temperature at which the proof stress of the material of the workpiece to be cut decreases. The point is that stable cutting becomes possible without accurately grasping the characteristics.

Of course, for example, a value obtained by directly detecting the temperature of the cutting edge or the temperature of the processed portion of the workpiece 32 is used as an index of the degree of decrease in the proof stress of the workpiece, and the feed control device is controlled according to the detected temperature. is also possible. In that case, it can be realized by changing the temperature setting in consideration of the type of the base material, including whether it is thermoplastic or thermosetting. In addition, as a cutting condition for a specific workpiece 32 associated with a reduction in yield strength due to heating by ultrasonic vibration, for example, when the control mode of the applied pressure as shown in FIG. 3 is known, a predetermined ultrasonic It is also possible to control the pressing force according to the control mode under the conditions of sonic excitation and feed speed. In any of these control modes, the speed is directly or indirectly controlled in a mode in which the speed is repeatedly increased and decreased with the degree of reduction in the proof stress of the workpiece as an index, so that excellent cutting can be realized. obtain. Furthermore, the increase/decrease in speed can be kept low by reducing the range of +0.5% and -0.5% from the hysteresis amount indicated by 80+5%-5% as explained above. be. It should be noted that the yield strength of the object to be processed can also be grasped as resistance to processing such as cutting by the action of external energy, for example. Specifically, such yield strength can be recognized as softening (decrease in hardness), increase in fluidity, decrease in yield point, etc. in the object to be processed due to temperature rise, depending on the characteristics of the object to be processed.

In addition, as described above, when the cutting tool is pulled out from the object after the cutting by the ultrasonically excited cutting tool is completed, the output of the ultrasonic oscillator that gives the ultrasonic vibration is made smaller than that during the cutting. and/or by temporarily stopping the ultrasonic excitation before withdrawing the processing tool, the technical idea of suppressing a decrease in processing accuracy when the processing tool is withdrawn while ensuring cutting processing efficiency. It is also possible to grasp the technical idea of the present invention as different from the technical concept of the present invention, which is to control the speed of the cutting process using the degree of reduction in the proof stress of the object to be processed as an index, and has new problems and solutions. Therefore, the following inventions are disclosed in this specification as inventions different from the present invention.

In one aspect of the invention different from the present invention, when cutting an object made of a synthetic resin with or without fiber reinforcement, the cutting edge of the processing tool is pressed against the object to be processed, and the cutting edge of the processing tool is pressed against the object. In addition to applying ultrasonic vibration, when withdrawing the machining tool from the object after cutting the object, the output of the ultrasonic oscillator that imparts the ultrasonic vibration is made smaller than during cutting, and Alternatively, a synthetic resin cutting method is provided in which an ultrasonic oscillator that applies ultrasonic vibrations is substantially temporarily stopped and restarted in accordance with withdrawal. In this aspect, "after cutting" includes "interruption of cutting" as well as "completion of cutting".

Further, one aspect of the invention that is still another aspect of the present invention is an apparatus for cutting an object to be processed made of a synthetic resin, comprising: an ultrasonic oscillator that generates ultrasonic vibration; a machining tool that is connected to the vibrator of the ultrasonic oscillator and is subjected to ultrasonic vibration; and/or a withdrawal stop control that substantially stops the ultrasonic oscillator before withdrawing the machining tool from the workpiece and restarts upon withdrawal. It is a cutting device for synthetic resin.

In addition, although not listed individually, the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, and such embodiments are the present invention. It goes without saying that any of them are included in the scope of the present invention as long as they do not deviate from the spirit of the present invention.
In addition, the present invention originally includes each of the inventions described in (i) to (xiv) below, and the configuration and effects thereof will be additionally noted.
The present invention
(i) When cutting an object made of synthetic resin, the cutting edge of a processing tool is pressed against the object to apply ultrasonic vibration to the machining tool, and the cutting edge of the object is applied to the object. A synthetic resin cutting method characterized by controlling the relative feed in the cutting direction using the degree of reduction in yield strength of the object to be processed as an index,
(ii) the synthetic resin cutting method according to claim 1, wherein the synthetic resin is a fiber-reinforced resin;
(iii) The synthetic resin cutting method according to claim 2, wherein the reinforcing fibers of the object to be processed are carbon fibers.
(iv) The synthetic resin according to any one of claims 1 to 3, wherein a load signal of an ultrasonic oscillator that applies the ultrasonic vibration is used as the indicator corresponding to the degree of reduction in yield strength of the object to be processed. cutting method,
(v) A target range of a predetermined width is set for the load signal of the ultrasonic oscillator, and the relative feed amount in the cutting direction of the cutting edge with respect to the workpiece so that the load signal stays within the target range. The synthetic resin cutting method according to claim 4, wherein the control is performed to change the
(vi) The synthetic resin cutting method according to any one of claims 1 to 5, wherein the object to be processed is a thermosetting resin,
(vii) The processing tool is a cylindrical punching tool having the cutting edge on the periphery of the tip, and the ultrasonic vibration is applied in at least one of the axial direction and the circumferential direction of the punching tool. The method for cutting the synthetic resin according to any one of Items 1 to 6,
(viii) The processing tool is a plate-like cutting tool having the cutting edge forward in the feed direction, and the ultrasonic vibration is applied in the direction along the plate surface of the cutting tool. The synthetic resin cutting method according to any one of
(ix) After cutting the object, when the machining tool is withdrawn from the object, the output of the ultrasonic oscillator for applying the ultrasonic vibration is made smaller than that during cutting. The synthetic resin cutting method according to any one of the above items,
(x) after cutting the object and before pulling out the machining tool from the object, stopping the ultrasonic excitation of the machining tool and then restarting the ultrasonic excitation;
10. The synthetic resin cutting method according to claim 9, wherein the withdrawal speed of the working tool after cutting is higher than the advancing speed of the working tool during cutting,
(xi) A cutting device for a workpiece made of synthetic resin, comprising an ultrasonic oscillator for generating ultrasonic vibrations and a cutting blade for cutting the workpiece, and a vibrator of the ultrasonic oscillator and a machining tool that is ultrasonically vibrated, and the cutting edge of the machining tool is pressed against the workpiece, and the machining tool is moved relative to the workpiece in the cutting direction and a feed control mechanism for controlling the speed of the relative movement of the workpiece and the machining tool by the feed mechanism, using the degree of reduction in proof stress of the workpiece as an index. A synthetic resin cutting device characterized by:
(xii) the synthetic resin cutting apparatus according to claim 11, wherein the synthetic resin is a fiber-reinforced resin;
(xiii) The synthetic resin cutting process according to claim 11 or 12, further comprising a pull-out controller that lowers the output of the ultrasonic oscillator when the tool is pulled out from the object to be processed, compared to that during cutting. Device,
(xiv) after cutting the object and before pulling out the machining tool from the object, stopping the ultrasonic excitation of the machining tool and then restarting the ultrasonic excitation; and a pull-out control unit for increasing the pull-out speed of the working tool after the end of cutting compared to the advancing speed of the working tool during cutting. 1. The synthetic resin cutting device according to item 1.
including inventions related to
In the invention described in (i) above, by pressing the ultrasonically vibrated cutting edge against the workpiece at a low feed rate, the synthetic resin that is the base material can be efficiently heated and the yield strength can be reduced. After that, by pressing the cutting edge at a high feed rate, the workpiece can be efficiently cut. It should be noted that the object to be processed in this aspect is irrespective of the presence or absence of fiber reinforcement. For example, in the case of an object to be processed made of a synthetic resin that does not have reinforcing fibers, the properties such as toughness of the object to be processed are unknown, or the performance of the processing tool and the state of the cutting edge are unknown. Also, by applying appropriate ultrasonic vibrations to the machining tool, the feed of the cutting edge is automatically appropriately adjusted for machining. Therefore, it is possible to cut various synthetic resin materials with appropriate processing efficiency and good processing accuracy without requiring advanced knowledge and experience.
In the invention described in (ii) above, by constantly vibrating the cutting blade with ultrasonic waves, it is possible to cut the fiber reinforced resin in the presence of the resin whose yield strength has been reduced by heating, resulting in delamination (interlayer peeling) and fluffing. It is possible to suppress the generation of burrs (fine hair-like particles formed by rubbing the surface) and burrs (protrusions generated when processing materials), and to avoid the generation of cutting waste as much as possible.
In the invention described in (iii) above, the cutting edge is efficiently pressed against the carbon fiber by reducing the proof stress of the base material by ultrasonic vibration, and both sides of the pressing portion of the cutting edge on the carbon fiber are Since the carbon fiber is fixedly supported by the base material whose yield strength is not reduced and tension is applied to the carbon fiber, the cutting action of the cutting blade that is ultrasonically excited can be efficiently exerted on the carbon fiber.
In the invention described in (iv) above, when the ultrasonically excited cutting edge is pressed against the workpiece for cutting, the ultrasonic excitation resistance of the cutting edge corresponds to the degree of reduction in the proof stress of the workpiece. By utilizing the fact that the load of the ultrasonic oscillator fluctuates due to changes in , the load signal of the ultrasonic oscillator can be employed as an index corresponding to the degree of reduction in yield strength of the workpiece. By adopting the load signal of the ultrasonic oscillator as an index corresponding to the degree of reduction in yield strength of the workpiece, as can be seen from the embodiments described later, stable cutting can be performed with simple equipment. control becomes feasible.
In the invention described in (v) above, as can be seen from the above-described embodiment, by simply setting the target range width for the load signal of the ultrasonic oscillator, the relative feed speed between the workpiece and the cutting edge and the workpiece. It is possible to stably perform the intended cutting process without being greatly affected by the state of the workpiece.
In the invention described in (vi) above, even when the workpiece is a thermosetting resin, the region where the pressing portion of the cutting blade is ultrasonically heated is limited, and the cutting blade is fed at a low feed speed. By repeating the decrease in yield strength due to local heating of the workpiece in the process and the rapid cutting of the workpiece at a high feed rate, it is possible to efficiently avoid damage due to excessive heating of the workpiece. It is possible to realize a cutting process with a high precision. When the synthetic resin is a fiber-reinforced resin in combination with the second aspect, the base material of the fiber-reinforced resin is a thermosetting resin.
In the invention described in (vii) above, secondary processing of drilling holes in synthetic resin can be realized. In general, the feeding direction of the cutting blade in punching is the thickness direction of the object to be processed. In the case of a fiber-reinforced resin employed as the reinforcing fiber, the cutting direction, which is the feeding direction of the cutting blade, is always substantially orthogonal to the running direction of the reinforcing fiber parallel to the surface of the object to be processed. Better cutting planes for the fibers can be stably achieved.
In the invention described in (viii) above, for example, a knife-shaped processing tool can be employed as the plate-shaped cutting tool, and ultrasonic vibration can be efficiently applied to the processing object, or the processing tool can be used as the processing object. It is also possible to pierce through an object, and it is possible to cut the object to be processed starting from the pierced point even from an intermediate portion of the object to be processed. In addition to perforating, it is also possible to cut an object to be processed in a straight line or a curved line. It should be noted that this aspect can be applied regardless of the purpose, process, type, etc. of the processing, such as trimming or finishing of the outer shape of the resin molded product.
In the invention described in (ix) above, when the working tool is pulled out from the object heated by ultrasonic waves, the output of the ultrasonic oscillator is made smaller than that during cutting, so that the working tool can be removed from the object. In addition, it is possible to suppress the problem that the object to be processed is pulled up in the extraction direction together with the processing tool and remains on the surface of the object to be processed in a raised manner. In this aspect, "after cutting" includes "interruption of cutting" as well as "completion of cutting".
In the invention described in (x) above, by temporarily stopping the ultrasonic vibration of the processing tool immediately before pulling it out, excessive softening of the processing object is suppressed, and the processing object that is pulled up in the pulling direction together with the processing tool is removed. can be suppressed. By combining this aspect with the above aspect (ix), it is possible to more effectively prevent the workpiece from being pulled up together with the machining tool in the pulling direction.
In the invention described in (xi) above, the synthetic resin can be cut according to the invention as described above.
In the invention described in (xii) above, even fiber-reinforced resin, which is difficult to cut, can be cut without greatly roughening the cut surface and while suppressing the generation of shavings.
In the invention described in (xiii) above, when the processing tool is pulled out from the object to be processed, the output of the ultrasonic oscillator is made smaller than that during cutting, so that the processing tool can be smoothly pulled out from the object to be processed. In addition, problems such as the workpiece being lifted in the drawing direction together with the machining tool and remaining on the surface of the workpiece in a raised manner can be suppressed.
In the invention described in (xiv) above, excessive softening of the workpiece can be avoided by stopping the ultrasonic excitation of the machining tool before the machining tool is pulled out from the workpiece. Therefore, while applying energy by ultrasonic vibration to the extent that it is possible to pull out the processing tool from the processing object, it is pulled up by the processing tool and remains on the surface of the processing object in a raised manner. problems can also be suppressed.

10 cutting device 12 base 14 electric cylinders 14x, 14y horizontal electric cylinders 14z, 14r electric cylinder 16 work table 18 vibrator 20 support arm 24 horn 26 cutting tool 28 ultrasonic oscillator 30 cutting edge 31 air hole 32 object to be processed Object 32a Upper surface side 32b Lower surface side 34 Auxiliary plate 36 Drive control device 40 Cutting device 42 Cutter knife (cutting tool)
44 cutting edge 45 chuck 46 cutter knife (cutting tool)
48 cutting edge 50 cutter knife (cutting tool)
52 Cutting blade 53 Cutting blade 54 Cutting unit 56 Withdrawal ultrasonic control unit (withdrawal control unit, withdrawal stop control unit)

Claims (13)

When cutting an object made of synthetic resin,
A cutting edge of a processing tool is pressed against the object to apply ultrasonic vibration to the processing tool, and relative feed in the cutting direction of the cutting edge with respect to the object to be processed is used as proof stress of the object to be processed. The speed is controlled using the degree of decrease as an index , and
A synthetic resin cutting method , wherein a load signal of an ultrasonic oscillator for applying the ultrasonic vibration is used as the index corresponding to the degree of reduction in yield strength of the object to be processed. A target range of a predetermined width is set for the load signal of the ultrasonic oscillator, and the relative feed amount in the cutting direction of the cutting edge with respect to the workpiece is changed so that the load signal stays within the target range. The synthetic resin cutting method according to claim 1 , wherein the control is performed. When cutting an object made of synthetic resin,
A cutting edge of a processing tool is pressed against the object to apply ultrasonic vibration to the processing tool, and relative feed in the cutting direction of the cutting edge with respect to the object to be processed is used as proof stress of the object to be processed. The speed is controlled using the degree of decrease as an index , and
A synthetic resin cutting method , wherein the object to be processed is a thermosetting resin . When cutting an object made of synthetic resin,
A cutting edge of a processing tool is pressed against the object to apply ultrasonic vibration to the processing tool, and relative feed in the cutting direction of the cutting edge with respect to the object to be processed is used as proof stress of the object to be processed. The speed is controlled using the degree of decrease as an index , and
Cutting of a synthetic resin, characterized in that, after the cutting of the object to be processed, when the working tool is withdrawn from the object to be processed, the output of the ultrasonic oscillator that imparts the ultrasonic vibration is made smaller than that during cutting. processing method. After cutting the object and before pulling out the machining tool from the object, stopping the ultrasonic excitation of the machining tool and then restarting the ultrasonic excitation,
5. The synthetic resin cutting method according to claim 4 , wherein the withdrawal speed of said working tool after completion of cutting is made higher than the advancing speed of said working tool during cutting. The synthetic resin cutting method according to any one of claims 1 to 5, wherein the synthetic resin is a fiber-reinforced resin. 7. The synthetic resin cutting method according to claim 6 , wherein the reinforcing fiber of the object to be processed is carbon fiber. 1-, wherein the processing tool is a cylindrical punching tool having the cutting edge on the periphery of the tip, and the ultrasonic vibration is applied in at least one of the axial direction and the circumferential direction of the punching tool. 8. The method for cutting a synthetic resin according to any one of 7 . 8. The processing tool according to any one of claims 1 to 7 , wherein the cutting tool is a plate-like cutting tool having the cutting edge forward in the feed direction, and the ultrasonic vibration is applied in a direction along the plate surface of the cutting tool. The method for cutting the synthetic resin according to item 1. A cutting device for an object to be processed made of synthetic resin,
an ultrasonic oscillator that generates ultrasonic vibrations;
a machining tool comprising a cutting edge for cutting the object to be processed, and coupled to the vibrator of the ultrasonic oscillator and subjected to ultrasonic vibration;
a feed mechanism that presses the cutting edge of the processing tool against the object to move the processing tool relative to the object in the cutting direction;
a feed control mechanism for speed-controlling the relative movement of the workpiece and the machining tool by the feed mechanism, using the degree of reduction in proof stress of the workpiece as an index ;
1. A synthetic resin cutting apparatus, comprising: a pull-out control unit that lowers the output of said ultrasonic oscillator when pulling out said machining tool from said object to be processed, compared to that during cutting. A cutting device for an object to be processed made of synthetic resin,
an ultrasonic oscillator that generates ultrasonic vibrations;
a machining tool comprising a cutting edge for cutting the object to be processed, and coupled to the vibrator of the ultrasonic oscillator and subjected to ultrasonic vibration;
a feed mechanism that presses the cutting edge of the processing tool against the object to move the processing tool relative to the object in the cutting direction;
a feed control mechanism for speed-controlling the relative movement of the workpiece and the machining tool by the feed mechanism, using the degree of reduction in proof stress of the workpiece as an index ;
a pull-out stop control unit that stops ultrasonic excitation of the machining tool after cutting the workpiece and before pulling out the machining tool from the workpiece, and then resumes ultrasonic excitation;
a withdrawal control unit that increases the withdrawal speed of the working tool after the cutting is finished compared to the forward speed of the working tool during cutting;
A synthetic resin cutting device comprising : A cutting device for an object to be processed made of synthetic resin,
an ultrasonic oscillator that generates ultrasonic vibrations;
a machining tool comprising a cutting edge for cutting the object to be processed, and coupled to the vibrator of the ultrasonic oscillator and subjected to ultrasonic vibration;
a feed mechanism that presses the cutting edge of the processing tool against the object to move the processing tool relative to the object in the cutting direction;
a feed control mechanism for speed-controlling the relative movement of the workpiece and the machining tool by the feed mechanism, using the degree of reduction in proof stress of the workpiece as an index ;
A synthetic resin cutting apparatus, wherein the feed control mechanism uses a load signal of an ultrasonic oscillator that applies the ultrasonic vibration as the indicator corresponding to the degree of reduction in proof stress of the object to be processed. The synthetic resin cutting apparatus according to any one of claims 10 to 12, wherein the synthetic resin is a fiber-reinforced resin.

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