JP2008207391A - Method and apparatus for trimming foamed urethane molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a trimming apparatus capable of precisely cutting off burr using an ultrasonic cutter. <P>SOLUTION: In trimming for cutting off burr containing at least a core material and a skin material, the ultrasonic cutter 2 is held to the hand of an articulated robot 1, the deformation quantity of the cutter blade of the ultrasonic cutter is at least once measured during a cycle for cutting the whole length of a part to be cut and the cutter blade is replaced with a good one in the case where a degree of the deformation quantity exceeds an allowable value. Since the use of the cutter blade can be stopped before the cutter blade is bent and deformed to a limit or above, the lowering of trimming processing can be prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a trimming apparatus for cutting a burr including at least a core material and a skin material of a foamed urethane molded product obtained by injecting a foamed urethane resin between a core material made of a hard resin and a soft skin material. And a trimming method.

  For example, an interior panel of an automobile is composed of a soft and comfortable skin layer, a core material made of a hard resin that defines the shape, and a foamed urethane layer interposed between the skin layer and the core material. . In some cases, the interior panel is manufactured by a method in which the layers are laminated and joined. In recent years, the core material and the skin material are arranged in a foaming mold, and foaming is performed between the core material and the skin material. Many manufacturing methods are used.

  According to this manufacturing method, the foamed urethane layer formed is integrally joined to the core material and the skin material by foam molding using the foamed urethane resin. Therefore, the lamination and joining processes can be omitted, and the productivity is high.

  By the way, in molding using a mold, burrs are inevitably generated in a molded product, and a trimming step for cutting burrs after molding is necessary. In a general molding method such as blow molding or injection molding, the thickness of the burr is thin, and trimming can be easily performed using a cutting blade, a hot blade, or the like. For example, Japanese Patent Laid-Open No. 2003-001639 describes a method of trimming a molded product having a complicated shape such as a steering wheel with a cutting blade held by a robot. Japanese Patent Application Laid-Open No. 04-224912 describes a method in which a thin and soft burr is cooled and hardened and then cut with a cutting tool.

  However, in the above-mentioned integral foam molding method for interior panels and the like, a pair of skin material and core material is overlapped at the peripheral edge in order to restrict the urethane foam resin from leaking between the skin material and the core material. It is sandwiched between molds and foamed. Therefore, it is inevitable that burrs composed of at least a skin material and a core material are generated at the peripheral edge of the molded product. However, since the core material is generally made of hard resin and the thickness thereof is generally thick, it is not easy to trim the burrs including the core material by trimming.

  Therefore, conventionally, trimming of burrs is performed by a so-called WTS (Water Trimming System) using ultra-high pressure water ejected from a nozzle. However, in WTS, since the cutting waste contains water, the processing man-hours become large, the equipment space becomes large, the apparatus rusts, and the working environment is bad. There is also a trimming method in which fusing is performed using a hot blade, but there are disadvantages such as high electric charges due to the use of a heater and scorching and burr on the cut surface.

Therefore, it was recalled to use an ultrasonic cutter. For example, Japanese Patent Application Laid-Open No. 07-241936 describes a method of trimming burrs of a spherical molded body such as a golf ball using an ultrasonic cutter. However, the cutter blade of an ultrasonic cutter is not strong enough, so it is sufficient for cutting soft and thin burrs such as golf ball burrs. It is not intended for use in resection. The interior panel has a complicated three-dimensional structure, and it is desirable to trim the interior panel using a robot. However, when trimming while holding the ultrasonic cutter in the robot hand, it is assumed that the cutter blade is bent at an early stage due to the resistance at the time of cutting, and the cutting accuracy is problematic.
JP2003-001639 JP 04-224912 JP 07-241936 A

  This invention is made | formed in view of the said situation, and makes it the problem which should be solved to enable it to excise a burr | flash with high precision using an ultrasonic cutter.

The feature of the trimming device of the present invention that solves the above problem is that a core material made of hard resin and a soft skin material are arranged in a mold, and urethane foam resin is injected between the core material and the skin material. A trimming device for excising a burr including at least a core material and a skin material of a foamed urethane molded product,
Detected by an ultrasonic cutter that cuts by vibration due to application of ultrasonic waves, an articulated robot that holds the ultrasonic cutter, a deformation amount detection means that detects the deformation amount of the cutter blade of the ultrasonic cutter, and a deformation amount detection means Output means for outputting a signal when the amount of deformation exceeds an allowable value.

  The trimming device according to another aspect of the invention is characterized by an ultrasonic cutter that cuts by vibration caused by application of ultrasonic waves, an articulated robot that holds the ultrasonic cutter, and a blade immediately after the cutter blade of the ultrasonic cutter during cutting. And an air blowing device that cools the already cut portion by blowing air.

The trimming method of the present invention is characterized in that a core material made of a hard resin and a soft skin material are placed in a mold, and a urethane foam resin is injected between the core material and the skin material to perform foam molding. A trimming method for excising a burr including at least a core material and a skin material of a urethane foam molded product,
Hold the ultrasonic cutter in the hand of the multi-indirect robot and measure the amount of deformation of the cutter blade of the ultrasonic cutter at least once during one cycle of cutting the entire length of the part to be cut. It is to replace the cutter blade with a non-defective product by the output signal when exceeding.

  Another feature of the trimming method of the invention is that the ultrasonic cutter is held in the hand of the multi-indirect robot, and air is blown to the already cut portion immediately after the cutter blade of the ultrasonic cutter while cutting the cut portion. It is in cooling.

  According to the trimming apparatus of the present invention, when the deformation amount of the cutter blade of the ultrasonic cutter exceeds an allowable value, the output means outputs a signal. Therefore, since the use can be stopped before the cutter blade is bent and deformed beyond the limit, it is possible to prevent the trimming accuracy from being lowered. According to the trimming method of the present invention, the amount of deformation of the cutter blade is measured at least once during one cycle of cutting the entire length of the portion to be cut, and the output signal when the degree of deformation exceeds the allowable value Since the cutter blade is replaced with a non-defective product, trimming with high accuracy can be performed at least in the next cycle.

  According to the trimming device and the trimming method of another invention, air is blown to the already cut portion immediately after the cutter blade by the air blowing device while the cut portion is being cut. That is, since it is cooled by the air, it is possible to prevent the cut surfaces of the already cut portions from being fused and to perform trimming with high accuracy.

  The trimming apparatus and the trimming method of the present invention is a foamed product in which a core material made of a hard resin and a soft skin material are placed in a mold, and a urethane foam resin is injected between the core material and the skin material to perform foam molding. It is used to cut burrs including at least a core material and a skin material of a urethane molded product. A core material is formed from hard resin, such as PP, PE, PA, PET, ABS, The wall thickness can use 0.8-3.0 mm. The skin material is formed of a soft resin such as vinyl chloride or thermoplastic elastomer, and the thickness is not particularly limited, but generally 0.6 to 2.0 mm is used. The burr may contain urethane foam.

  The ultrasonic cutter converts electrical energy into ultrasonic vibrations, transmits the ultrasonic vibrations to the cutter blades, and the core material and skin material are removed by frictional heat generated between the cutter blades and burrs due to the vibration of the cutter blades. Disconnect. Moreover, the urethane foam is physically cut by mechanical energy caused by vibration. As this ultrasonic cutter, a commercially available one in which a cutter blade is replaceably attached to a vibrator such as a PZT electrostrictive vibrator can be used. As the articulated robot, a commercially available general robot can be used.

  The deformation amount detecting means detects the deformation amount of the cutter blade of the ultrasonic cutter, and various gauges such as a dial gauge can be used. The detection of the deformation amount by the deformation amount detection means is performed at least once during one cycle of cutting the entire length of the part to be cut. For example, at a reset position of the robot, a dial gauge or the like is advanced and retracted toward the cutter blade of the ultrasonic cutter, and the deformation amount of the cutter blade is detected. When the degree of deformation exceeds the allowable value, the ultrasonic cutter is replaced with a non-defective product. As a result, trimming in the next cycle can be performed with high accuracy and trimming failure can be prevented. Moreover, one cutter blade can be used to the maximum and there is no waste.

  The output means is a means for outputting a signal when the deformation amount detected by the deformation amount detection means exceeds an allowable value. It is desirable to drive the perception means such as turning on the lamp or sounding a warning sound according to the output signal, and to stop the driving of the robot. As a result, it is possible to surely prevent the trimming accuracy from being lowered, and it is possible to reliably perceive that the cutter blade has been deformed, thereby preventing forgetting to replace it.

  In the trimming apparatus and the trimming method of the present invention, load detecting means for detecting a load acting on the cutter blade from the part to be cut during cutting is provided, and the cutter blade before the load detected by the load detecting means exceeds a predetermined value. It is desirable to control the multi-joint robot so that the cutting is continued from the cut portion and then inserted again into the cut portion. The load detection may be performed automatically during trimming, and the cutter blade may be automatically inserted and removed, but the load condition applied to the cutter blade by test trimming is detected in advance by the load detection means, and the load is detected. The articulated robot may be programmed to insert and remove the cutter blade at a high part. By removing the cutter blade from the part to be cut, the stress acting on the cutter blade from the part to be cut is eliminated and reset. Therefore, permanent deformation of the cutter blade can be prevented in advance, and the trimming accuracy can be further improved since the cutting direction can be made the normal direction when the cutter blade is inserted again into the cut portion and cut.

  In the trimming method of the present invention, the angle of the moving direction of the cutter blade with respect to the reference cutting line is cut at an angle that intersects the reference cutting line at an acute angle in one direction, and after cutting 5 to 30 mm, with respect to the reference cutting line It may be cut at an angle that intersects the other direction on one side and the other side at an acute angle, and the one direction and the other direction are switched every cutting length of 5 to 30 mm. By cutting in a zigzag manner in this way, the deformation direction of the cutter blade due to the stress acting from the part to be cut can be averaged, and the life of the cutter blade can be extended in some cases.

  In another trimming device and trimming method of the invention, air is blown to the already cut portion immediately after the cutter blade by the air blow device while the cut portion is being cut. That is, since the molten resin is cooled and solidified by the air, it is possible to prevent the cut surfaces of the already cut portions from being fused and to perform trimming with high accuracy.

  Hereinafter, the present invention will be described specifically by way of examples.

  The workpiece 100 to be trimmed in this embodiment is a door panel of an automobile. As shown in FIG. 2, a core material 101 made of PP and having a thickness of 2.0 mm, a skin material 102 made of a thermoplastic elastomer, and a core material 101 It is comprised from the urethane foam molded object 103 with which the space | interval material 102 is filled. In this work 100, first, the core material 101 and the skin material 102 are arranged along the mold surfaces of the pair of molds 200 and 201, and the peripheral portions of the core material 101 and the skin material 102 are sandwiched between the molds 200 and 201. To do. Thereafter, a foamed urethane molded body 103 is formed by injecting a predetermined amount of foamed urethane resin from an injection port (not shown) to cause foaming. At this time, since the peripheral portions of the core material 101 and the skin material 102 are sandwiched between the molds 200 and 201, leakage of the urethane foam resin is prevented.

  However, as the product shape, the portion sandwiched between the molds 200 and 201 is not necessary, and it is necessary to perform trimming to cut the peripheral portion along the LL line in FIG. 2 after foam molding.

  FIG. 1 shows a trimming apparatus of this embodiment. This trimming apparatus is composed of an articulated robot 1, an ultrasonic cutter 2 attached to the robot hand 10, and a dial gauge 3.

  As shown in FIG. 3, the ultrasonic cutter 2 includes a case 20 containing a PZT electrostrictive vibrator, a holder 21 extending from the vibrator, and a cutter blade 22 held exchangeably by the holder 21. The vibrator in 20 is connected to the oscillator 23. The cutter blade 22 ultrasonically vibrates in the longitudinal direction at a maximum vibration amplitude of 70 μm and a frequency of 22,000 times / second.

  From the robot hand 10, the nozzle 4 extends toward the cutter blade 22. The nozzle 4 is connected to an air compressor 40, and the tip of the nozzle 4 is positioned immediately after the cutter blade 22 in the direction of travel of the cutter blade 22.

  As shown in FIG. 4, the dial gauge 3 is installed at a position facing the cutter blade 22 at the reset position of the articulated robot 1. A dimension discrimination sensor 31 is attached to the detection rod 30 extending from the dial gauge 3 so that the movement dimension of the detection rod 30 can be detected with high accuracy. The dial gauge 3 and the dimension discrimination sensor 31 are held by an XY stage 32 so that the tip position of the detection rod 30 can be adjusted.

  In this embodiment, the articulated robot 1 is taught to return to the reset position and stop whenever the cutter blade 22 has cut the entire circumference of the peripheral edge of the workpiece 100. In this reset position, the cutter blade 22 is in a position where the surface thereof faces the tip of the detection rod 30, and the detection rod 30 is advanced toward the surface of the cutter blade 22. The detection rod 30 is advanced until the tip abuts against the surface of the cutter blade 22, and the output signal of the dimension discrimination sensor 31 at that time is input to the control device 33. The control device 33 analyzes the output signal of the dimension discrimination sensor 31 and detects the advance length of the detection rod 30.

  The control device 33 stores the advance length of the detection rod 30 in the case of a new (good) cutter blade 22 as a reference value, and the control device 33 calculates the difference between the actual advance length of the detection rod 30 and the reference value. taking measurement. If this difference exceeds a predetermined value, it is determined that the amount of deformation of the cutter blade 22 exceeds the allowable value, and the control device 33 lights the warning lamp 5. That is, the control device 33 constitutes the output means referred to in the present invention.

  When the warning lamp 5 is turned on, the operator replaces the cutter blade 22 with a new one. This prevents the deformed cutter blade 22 from being used in the next cycle of trimming, so that trimming failure can be prevented and trimming can be performed with high accuracy.

  Next, teaching of the articulated robot 1 will be described.

  First, the articulated robot 1 is driven at the reset position, and the cutter blade 22 is inserted into a predetermined position of the workpiece 100 at a predetermined depth while being ultrasonically vibrated. Then, as shown in FIG. 5, when the cutter blade 22 is moved a predetermined distance along the peripheral edge of the workpiece 100, the advancement of the cutter blade 22 is stopped, and the cutter blade 22 is once pulled out of the workpiece 100 and held for a very short time. Insert it again into the cutting part of the workpiece 100. Subsequently, the cutter blade 22 is moved by a predetermined distance in the traveling direction along the peripheral edge of the workpiece 100. Similarly, the cutter blade 22 is once pulled out of the workpiece 100 and then inserted into the cutting portion of the workpiece 100 again. While repeating this, the articulated robot 1 trims the entire circumference of the workpiece 100, returns to the reset position again, and stops. After stopping, the amount of deformation of the cutter blade 22 by the dial gauge 3 is measured.

  The moving distance of the cutter blade 22 that continuously cuts at a time, that is, the distance from the extraction position of the cutter blade 22 to the next extraction position is adjusted according to the stress acting on the cutter blade 22 from the workpiece 100. For example, when only the skin material 102 is trimmed without the core material 101, the distance is increased because the acting stress is small. Further, when cutting the curved portion, the stress is large, so the distance is shortened. By adjusting in this way, it is possible to perform trimming with high accuracy, prevent a large stress from acting on the cutter blade 22, and extend the life until the cutter blade 22 is replaced. Therefore, productivity is improved.

  If the stress on the cutter blade 22 is not relieved in the trimming apparatus of the present embodiment, teaching may be performed so that the cutting angle of the cutter blade 22 changes in a staggered manner. That is, as shown in FIG. 6, the cutter blade 22 travels at an angle that intersects the reference cutting line at an acute angle with respect to the reference cutting line, cuts 5 to 30 mm, and then cuts the reference cutting line. Then, the movement of the articulated robot is controlled so as to cut at an acute angle to the other direction opposite to the one direction, and to switch between the one direction and the other direction every cutting length of 5 to 30 mm.

  By cutting in a zigzag manner in this way, the deformation direction of the cutter blade 22 due to the stress acting from the workpiece 100 can be averaged, and the life of the cutter blade 22 may be further increased.

  Further, while the articulated robot 1 is driven, air is always blown from the nozzle 4. The opening of the nozzle 4 is located immediately after the cutter blade 22 with respect to the traveling direction of the cutter blade 22 and faces the surface of the workpiece 100. That is, the opening of the nozzle 4 faces the already cut portion cut by the cutter blade 22. Therefore, since the already cut portion is cooled immediately after cutting by the air blown from the nozzle 4, it is possible to prevent the cut surfaces of the already cut portion from being fused.

It is a side view of the trimming device concerning one example of the present invention. It is principal part sectional drawing which shows the workpiece | work trimmed with the trimming apparatus which concerns on one Example of this invention with a metal mold | die in the state before the demolding after foam molding. It is principal part expansion explanatory drawing of the trimming apparatus which concerns on one Example of this invention. It is principal part expansion explanatory drawing of the trimming apparatus which concerns on one Example of this invention. It is a time chart which shows the content of teaching in the trimming method which concerns on one Example of this invention, and shows the relationship between time and the insertion depth of a cutter blade. It is explanatory drawing which shows the content of teaching in the trimming method which concerns on one Example of this invention, and shows the actual cutting line with respect to a reference | standard cutting line.

Explanation of symbols

1: Articulated robot 2: Ultrasonic cutter 3: Dial gauge (deformation detection means)
4: Nozzle 5: Warning lamp
22: Cutter blade 30: Detection rod

Claims (6)

A foamed urethane molded product formed by foaming by placing a core material made of a hard resin and a soft skin material in a mold and injecting a foamed urethane resin between the core material and the skin material. A trimming device for cutting a burr including a core material and the skin material,
An ultrasonic cutter that cuts by vibration caused by application of ultrasonic waves;
An articulated robot holding the ultrasonic cutter;
Deformation amount detecting means for detecting the deformation amount of the cutter blade of the ultrasonic cutter;
A trimming apparatus comprising: output means for outputting a signal when the deformation amount detected by the deformation amount detection means exceeds an allowable value.   Load detecting means for detecting a load acting on the cutter blade from the cut portion during cutting, the cutter blade is removed from the cut portion before the load detected by the load detection means exceeds a predetermined value, 2. The trimming apparatus according to claim 1, wherein the articulated robot is controlled so as to be inserted again into the part to be cut and to continue the cutting. A foamed urethane molded product formed by foaming by placing a core material made of a hard resin and a soft skin material in a mold and injecting a foamed urethane resin between the core material and the skin material. A trimming device for cutting a burr including a core material and the skin material,
An ultrasonic cutter that cuts by vibration caused by application of ultrasonic waves;
An articulated robot holding the ultrasonic cutter;
A trimming device comprising: an air blow device that blows and cools an air to an already cut portion immediately after the cutter blade of the ultrasonic cutter during cutting. A foamed urethane molded product formed by foaming by placing a core material made of a hard resin and a soft skin material in a mold and injecting a foamed urethane resin between the core material and the skin material. A trimming method for excising a burr including a core material and the skin material,
The amount of deformation of the cutter of the ultrasonic cutter is measured at least once during one cycle of holding the ultrasonic cutter in the hand of the multi-indirect robot and cutting the entire length of the part to be cut. A trimming method, wherein the cutter blade is replaced with a non-defective product by an output signal when the value is exceeded.   The cutting blade is removed from the cut portion before the load applied to the cutter blade acting from the cut portion during cutting exceeds a predetermined value, and then inserted again into the cut portion to continue cutting. 5. The trimming method according to 4. A foamed urethane molded product formed by foaming by placing a core material made of a hard resin and a soft skin material in a mold and injecting a foamed urethane resin between the core material and the skin material. A trimming method for excising a burr including a core material and the skin material,
A trimming method, wherein an ultrasonic cutter is held in a hand of a multi-indirect robot, and air is blown to an already cut portion immediately after the cutter blade of the ultrasonic cutter while the cut portion is being cut, thereby cooling.

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