JP2005343078A - Gate cutting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gate cutting device which has a sprue and a runner, can completely cut off gate parts connected to products when each product is taken out from an integrated molding having the products through gates, can cut the gate parts while preventing the occurrence of cracking in the products, and does not produce fine powder. <P>SOLUTION: The gate cutting device 1 is composed of a cutter 30 comprising a fixed blade 31 and a movable blade 32 having a heater 36, a blade tip regulation part for regulating the fixing position of the fixed blade 31, and a work piece chuck member 20 having a blade tip guide part to be a guide for the movable blade 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gate cut device used for a gate cut operation of a plastic molded product, and more particularly to a gate cut device suitable for taking out a small molded product such as a plastic lens.

  Plastic products molded by an injection molding machine are taken out in the form of a single molded product through a spool, a runner, and a gate. After molding, the gate is cut (cut) to separate the product from the runner. It was. Conventionally, such gate cutting work has been performed manually, but recently, for the purpose of labor saving, the use of gate cutting robots that automatically cut off product parts from molded bodies with runners taken out from molding machines has become widespread. It's getting on.

  In the latest example of a gate cut robot, it has a moving means in three orthogonal axes and a rotating means consisting of a two-phase or five-phase stepping motor, and a chuck member for gripping a molded body is configured to be operable in four axes. Is circulating. That is, in this type of gate cutting device, after the chuck member receives the molded body taken out from the molding machine by the take-out machine, it moves in the three-axis direction to the cutting position of the gate cutter provided at the fixed position. Insert the molded body spool in a positioned state, rotate the molded body each time the gate cutter cuts the gate of each product, and continuously cut the product gates that are usually mounted in a symmetrical arrangement. It is configured to go.

  Examples of the gate cutter for cutting the gate include an air cutter operated by air pressure and a method of cutting with a laser beam.

Furthermore, a gate cutting method and apparatus having a pre-cut process for cutting a gate part of a plastic molded product and a finish cutting process for cutting a pre-cut surface of the cut gate part have already been disclosed. (For example, see Patent Document 1)
Japanese Patent Laid-Open No. 11-19981 (page 1-4, FIG. 1)

  However, recently, plastic molded products such as small lenses have been further miniaturized, and in the conventional method of simply cutting the gate portion using a grindstone or a cutter, when gripping and cutting a small product, However, it is difficult to cleanly cut along a desired lens outer shape, and cracks, cracks, burrs, and the like may occur during cutting.

  Further, when cutting using laser light, there is a harmful effect due to large heat energy, so that it is not suitable as a gate cut for manufacturing a small plastic molded product requiring precision such as a micro lens.

  Further, in the example in which the cutting is finished and then cut along the desired lens outer shape, not only the XY biaxial control device for cutting is required, but also the fine powder generated during cutting is There is a problem that it adheres to the product and surrounding devices due to static electricity.

The object of the present invention is to completely cut out the gate part connected to the product when taking out each product from the integrally molded body having a plurality of products through the gate and having a spool and a runner in order to solve the above problems. Another object of the present invention is to provide a gate cut device that can be cut with high accuracy without causing cracks or cracks in the product and that does not generate fine powder.

  In order to achieve the above object, the invention according to claim 1 includes a chuck unit that includes a spool and a runner, and further holds an integrally molded body having a product via a gate, and of the held integrally molded body, a product. A work cutting device comprising a work chuck member for gripping a workpiece and a cutter for cutting a gate connected to the gripped product, and assembling the work chuck member and the cutter integrally to a support body, The cutter is configured to move along the front end surface of the work chuck member on the side where the work chuck member grips the product.

  According to the invention according to claim 1 having the above-described configuration, since the work chuck member and the cutter are integrally assembled, the predetermined position of the product gripped by the work chuck member can always be cut correctly. .

  The invention according to claim 2 is a cutter in which the cutter includes a fixed blade and a movable blade having a heater, and the movable blade moving in parallel to the fixed blade moves to cut the gate. The front end surface includes a blade edge restricting portion for restricting a blade edge position of the fixed blade and a blade edge guide portion serving as a guide for the movable blade.

  According to the invention according to claim 2 having the above-described configuration, the work chuck member can regulate the blade edge position of the fixed blade and the moving position of the movable blade in a state in which the product is gripped, and always has a predetermined position. The gate connected to the product can be cut with.

  According to a third aspect of the invention, the product is a circular plastic molded product, and the work chuck member includes two left and right chuck arms and a linear motion member that supports the two chuck arms so as to be able to contact and separate. When the arc-shaped groove portions that are in contact with two points of the circular outer shape portion of the product are respectively disposed in the joint portions of the chuck arms facing each other, and the product is gripped by the arc-shaped groove portions to be joined. The front end surface of each chuck arm on the side that grips the product is flush with the front end surface of the chuck arm member, and a part of the circular outer shape portion of the product is slightly formed from the front end surface. It is characterized by having a structure that is exposed to.

  According to the invention according to claim 3 having the above-described configuration, the circular plastic molded product can be accurately grasped, and the gate part to be cut is exposed from the front end surface of the chuck arm, and along the front end surface. By moving the movable blade, the gate portion can be reliably cut and removed.

  The invention according to claim 4 is characterized in that the movable blade is mounted on a support member via a leaf spring and a spacer made of a heat insulating material, and the blade edge is moved when the movable blade approaches or separates from the fixed blade. It is characterized by being configured to be driven by a cylinder member while being urged to be pressed by the guide portion.

  According to the invention of claim 4 having the above-described configuration, the heat of the heater is prevented from being transferred to the support member, and the movable blade is always in contact with the blade edge guide portion and reliably at a desired speed. The movement can be controlled.

  According to a fifth aspect of the invention, the cylinder member is an air hydro cylinder, and the moving speed of the movable blade by the air hydro cylinder is a speed according to the degree of softening of the product that is softened by heating of the heater. It is a feature.

  According to the invention according to claim 5 having the above-described configuration, the product that is a plastic molded product can be reliably cut to the end at a low speed according to the degree of softening while being softened with a heater, and cracks and cracks can be obtained. It can be cut accurately and neatly without producing fine powder.

  According to a sixth aspect of the present invention, when the movable blade is at a position separated from the fixed blade, the movable blade is located on a gentle slope provided at a lower portion of the blade edge guide portion and is in a state separated from the blade edge guide portion and is insulated. It is configured to abut against a separator made of a material, and is configured to abut against the blade edge guide part from the middle of movement in the fixed blade direction during a cutting operation, and move while remaining in contact to cut the gate. It is said.

  According to the invention concerning Claim 6 which has said structure, the heat of the heater with which a movable blade is mounted | worn is not transmitted other than a movable blade during the standby of a movable blade, and it is heat efficient and safe.

  According to the present invention, when removing each product from an integrally molded body having a plurality of products through a gate and having a spool and a runner, the gate portion connected to the product can be completely excised and the product is cracked. It is possible to obtain a gate cut device that can be cut with high accuracy without causing cracks and that does not generate fine powder.

  The purpose is to obtain a gate cutting device that can completely cut the gate part connected to the plastic molded product, can be cut with high precision without causing cracks and cracks in the product, and does not generate fine powder. A work chuck member having a cutter composed of a fixed blade and a movable blade having a heater, a blade edge restricting portion for restricting a fixed position of the fixed blade, and a blade edge guide portion serving as a guide guide for the movable blade; This is realized by using a gate cut device having a configuration including:

  Embodiments of a gate cut device according to the present invention will be described below with reference to FIGS.

  FIG. 1 is an enlarged view of a main part of a gate cut device according to the present invention, FIG. 2 is an overall side view, and FIG. 3 is an overall front view. 4A and 4B show the product and its gripping portion, where FIG. 4A is a plan view of the product gripped, FIG. 4B is a side view thereof, and FIG. 4C is an enlarged view of the product taken out. The figure is shown. FIG. 5 is a perspective view showing an example of an integrally molded body, where (a) is an example in which four radial runners are provided with four products, and (b) is eight radial runners. This shows an example of molding the product.

  A gate cut device 1 according to the present invention includes a spool and a runner, and further cuts a gate connected to each product from an integrally molded body having a plurality of products via the gate, and takes out each product. As shown in FIG. 2, the apparatus includes a chuck unit 10 that holds the integrally molded body 2, a work chuck member 20 that holds a single product, and a cutter 30 that cuts the gate.

  As the integrally molded body 2, for example, as shown in FIG. 5 (a), four radial runners 2b protrude from a spool 2a, and a product P is molded at the tip of the runner 2b. . Further, there is an integral molded body 2A that branches into the tip of the runner 2b as shown in FIG.

  As described above, the integrally molded body 2 which is a plastic molded product molded by an injection molding machine has a configuration in which a plurality of products P are symmetrically arranged around the spool 2a. The spool 2a is a resin injection path at the time of injection molding and also serves as a shaft rod for gripping the integrally molded body 2. Further, a runner 2b, which is a resin flow path having a large diameter, continues from the spool 2a in a plurality of directions, and a product P is molded at each tip via a gate 2c having a small diameter.

  Therefore, in order to take out each product P, it is necessary to cut each gate 2c and separate them one by one. Further, to cleanly cut the product P along the desired outer shape, it is important to surely remove the connecting portion (hereinafter referred to as the gate portion G) between the product P and the gate 2c.

  The chuck unit 10 holds the integrally molded body 2 including a plurality of products P via the spool 2a, and moves in three axis directions to position the product P to be taken out at the cutter cutting position which is a fixed position. After the workpiece chuck member 20 grips the product P, the cutter 30 cuts the gate portion G connected to the product P and takes out the product P. After taking out one product, it is further moved in the three-axis direction, a new product P is inserted into the cutting position, and the gate part G of the product P, which is usually mounted in a symmetrical arrangement, is continuously connected. It is the composition which cuts.

  The gate portion G cut by the cutter 30 is a connecting portion between the gate 2c and the gate 2c and the product P. Therefore, the gate 2c can be completely removed from the product P, and the product P can be accurately cut into a desired outer shape and taken out.

  As shown in FIG. 1, the product P is inserted into the cutting position while the chuck unit 10 holds the integrally molded body 2. The chuck unit 10 is movable in three horizontal directions, ie, a horizontal direction and a vertical direction. There is no particular limitation as long as it is a simple configuration. However, a robot hand that can move in the horizontal direction and the vertical direction and can turn further is preferable because it can be freely set and operated.

  As shown in FIGS. 2 and 3, the work chuck member 20 includes a pair of left and right chuck arms 21 and 22 that can move on a slide rail 23. Are moved and joined. That is, the slide rail 23 and the cylinder 24 constitute a linear motion member 25 that drives the chuck arm.

  In addition, arc-shaped groove portions 21a and 22a are respectively formed in the joint portions to be opposed to each other, and the product P is sandwiched and held by the arc-shaped groove portions 21a and 22a to be joined from a separated state. is there.

  FIG. 4A shows a state in which the product P is gripped. The product P has a substantially circular outer shape, and the arc-shaped groove portions 21a and 22a are diamond-shaped ellipse or V-shaped groove portions. . This is because when the product P is gripped by the groove portion, the product P is gripped in contact with two points on the outer periphery, not the entire outer periphery.

  For this purpose, the arcuate groove 21a is in contact with the product P at two points a, and the arcuate groove 22a is in contact with the product P at two points b.

When the chuck arms 21 and 22 approach each other and grip the product P, a part of the circular outer portion on the side to which the gate 2c is connected is slightly exposed from the front end surface A of the chuck arm. This is because the gate portion G is cut to reliably remove the gate 2c, and the arc-shaped groove portions 21a and 22a may be provided directly connected to the front end surface A.

  When the product P is inserted into the cutting position while the chuck unit 10 holds the integrally molded body 2, the product P is positioned below the upper fixed blade 31 constituting the cutter 30 as shown in FIG. 2. Insert as you do. Then, as described above, the chuck arms 21 and 22 are driven via the linear motion member 25 so that the workpiece chuck member 20 grips the product P.

  At this time, the fixed blade 31 is in a state in which the blade edge is in contact with the front end surface A of the work chuck member 20 and the position of the blade edge is regulated. That is, the front end surfaces of the chuck arms 21 and 22 are the cutting edge restricting portions of the fixed blade 31.

  Then, the other movable blade 32 constituting the cutter 30 moves until it comes into contact with the fixed blade 31 to cut the gate portion G.

  The movable blade 32 is driven by a cylinder member 34 in a direction in which the movable blade 32 abuts and separates from the fixed blade 31 along the slide rail 33. That is, the cutter 30 is a cutter that cuts the product by moving the movable blade 32 facing in parallel with the fixed blade 31 to abut against the fixed blade 31.

  Further, the movable blade 32 is configured to move along the front end face A of the chuck arms 21 and 22 holding the product P. In other words, the guide end moves while the cutting edge of the movable blade is in contact with the front end face A, and the front end face A also becomes a cutting edge guide portion of the movable blade 32.

  The front end surface A is a generic name for the front end surface A1 on the chuck arm 21 side and the front end surface A2 on the chuck arm 22 side. Further, since both the fixed blade 31 and the movable blade 32 are in contact with both the front end surface A1 and the front end surface A2, the positions of the front end surface A1 and the front end surface A2 match the surfaces correctly. Needless to say, they can be collectively referred to as a front end face A.

  The movable blade 32 is attached to a support member 35 that is attached to a cylinder member 34 and is slidable along the slide rail 33 via a leaf spring 37. In addition, the blade edge is always urged in the direction of the front end surface A, and when the cylinder member 34 is moved, the cutting edge moves in a state of being in contact with the front end surface A. Therefore, the cutting edge of the movable blade 32 is configured to accurately come into contact with the cutting edge of the fixed blade 31 that is in standby with the cutting edge abutting the front end surface A.

  As described above, the front end surface A is also a cutting edge restricting portion that contacts the fixed blade 31 and a cutting edge guide portion that moves while the cutting edge of the movable blade 32 is in contact therewith, so the cutting edge of the fixed blade 31 and the cutting edge of the movable blade 32 are included. Are completely in contact with each other, and the gate portion G can be cut reliably and cleanly.

  Further, the movable blade 32 includes a heater 36, and the product P can be softened and melted by the heat of the heater. In addition, the movable blade 32 provided with the heater 36 is fixed to the support member 35 via the separator 38 that is a heat insulating material. The heater 36 heats the movable blade 32, but heat is not transmitted to other members. In this configuration, no extra heat transfer is performed.

The heater 36 is a cylindrical cartridge heater, and is embedded in a heater holder 36A to which the movable blade 32 is fixed. The movable blade 32 is screwed to the heater holder 36 </ b> A so that the movable blade 32 is separated from the heater 36 and is detachable. Therefore, only the movable blade 32 can be easily replaced during maintenance or the like.

  The product P is, for example, a plastic lens, and a configuration in which the product P is simply pushed at once with a metal cutter is inappropriate because the resin lens is cracked or broken. Moreover, when it is set as the structure melt | dissolved and cut | disconnected with a heat cutter, it may deform | transform with heat | fever and a desired external dimension may not be obtained.

  Therefore, in this embodiment, the product P is softened by the heat of the heater and is cut by the cutter 30. That is, even if it cut | disconnects with metal cutters 30, it is the structure softened and cut | disconnected to such an extent that a crack and a crack do not arise.

  For that purpose, it is inappropriate that the moving speed of the movable blade 32 is too fast or too slow, and it is important to move it at a predetermined slow speed according to the degree of softening. Furthermore, it is necessary to move the movable blade 32 at a low speed and reliably press the fixed blade 31 to cut the product P, and a pressing force that reliably presses to the end even at a constant low speed is required.

  In order to satisfy this condition, the cylinder member 34 is an air-hydro cylinder, and a speed controller SC is mounted to control the driving speed of the cylinder member 34, that is, the moving speed of the movable blade 32. In this way, the product P such as a plastic lens can be made to have a desired outer shape by driving the movable blade 32 by adjusting the speed so as to cut the product P accurately and cleanly without causing cracks or cracks. It can be cut out into a shape and taken out.

  The movable blade 32 is moved by the cylinder member 34 between a position separated from the fixed blade 31 and a position in contact with the fixed blade 31. However, the movable blade 32 is in contact with the front end surface A at the separated lower end position. Not. As shown in FIG. 4B, a gentle slope B is formed below the front end surface A of the work chuck member 20, and the movable blade 32 is not in contact with the plate spring 37 even when it is urged. Because. At this time, the movable blade 32 is in contact with a separator 39 made of a heat insulating material (see FIG. 1). For this reason, when the movable blade 32 is in the standby position at the lower end, the heat of the heated movable blade 32 is not transferred to other members, and particularly to the work chuck member 20 that grips the product P. Heat transfer is prevented.

  Further, at the time of the cutting operation, the movable blade 32 moves to the upper side in the drawing and comes into contact with the fixed blade 31, and is configured to come into contact with the front end surface A in the middle thereof. Therefore, when the product P held by the work chuck member 20 is cut, the cutting edge of the movable blade 32 is in contact with the front end surface A and its position is regulated. Further, a stopper 40 is provided for restricting the moving end position where the movable blade 32 contacts the fixed blade 31.

  The stopper 40 is a screw rod fixed to the support body 41, and has a configuration in which the support member 35 is stopped by abutting against a protruding portion 35 </ b> A provided at one end of the support member 35 that is moved by the cylinder member 34. That is, by adjusting the screw rod, the stop position of the movable blade 32 can be regulated at a position where the gate portion G cut by the fixed blade 31 and the movable blade 32 is reliably cut. You can adjust the hit. Therefore, it can prevent that the blade edge | tip of the fixed blade 31 and the movable blade 32 which abuts for every cutting operation | movement is damaged, and can use each blade member for a long time.

A support body 41 that integrally supports the work chuck member 20, the cutter 30, and the like is mounted on an X-axis stage 43 that can be moved and adjusted in one axial direction via a connecting member 42 (see FIG. 2). The moving amount is finely adjusted by the meter head 43A. Therefore, while being held by the chuck unit 10, the positions of the work chuck member 20 and the cutter 30 can be finely adjusted according to the position of the product P of the integrally molded body 2 to be cut.

  Further, since the work chuck member 20 and the cutter 30 are integrally assembled to the support main body 41, the position at which the product P gripped by the work chuck member 20 is cut can always be correctly cut.

  As shown in FIG. 4 (c), the product P to be taken out by cutting the gate portion G has a circular shape including a lens portion main body P1 and an annular peripheral flange P2, and a part of the peripheral flange P2 is straight. It is a shape provided with a cut portion K. Therefore, when preparing the products P to be taken out, the cut portion K can be used, which is preferable.

  The cut portion K is desirably small to some extent within the range of the peripheral flange P2. For this purpose, it is important to reduce the cutting thickness t. In this embodiment, the fixed blade 31 and the movable blade 32 constituting the cutter are sharpened, and the position of the product P is set to each position. It was set as the structure regulated by the work chuck member 20 to hold | grip. That is, the work chuck member 20 that holds the product P at a correct position is provided with a blade edge restricting portion that restricts the fixed position of the fixed blade 31 and a blade edge guide portion that restricts the moving position of the movable blade 32.

  As described above, since the accurate position of the gripped product P is cut, in this embodiment, the cutting thickness t can be reduced to about 50 μm. Therefore, by setting the peripheral flange P2 to have a width of 50 μm or more, the cut portion K can be suppressed within the peripheral flange P2, and the lens portion main body P1 is not damaged or cut.

  The product P taken out from the integrally molded body 2 needs to be taken out while maintaining its posture and aligned in the same direction. For that purpose, when the work chuck member 20 is opened and the product P is taken out, the workpiece P may be removed by using a suction device and the cut portions K may be aligned. Further, the method is not particularly limited.

  As the heater 36, a cartridge heater having a temperature controller is employed. This is because the cutting edge temperature of the movable blade 32 is set to an optimum temperature for cutting while softening the product P. Depending on the resin component and size to be cut, the temperature is set to a temperature corresponding to an appropriate cutting speed. This is for setting.

  As described above, according to the present invention, since the work chuck member and the cutter are integrally assembled, the predetermined position of the product gripped by the work chuck member can always be cut correctly. Furthermore, even if it is a small resin molded product such as a plastic lens, it is configured to cut the product P at a speed according to the degree of softening while softening the product P, so that fine powder or the like does not occur during cutting, There is no static electricity. Further, it can be cut and taken out while maintaining a desired outer shape without cracks or cracks, and a gate cutting device that does not require polishing work after cutting can be obtained.

It is a principal part enlarged view of the gate cut apparatus which concerns on this invention. It is a whole side view of a gate cut device. It is a whole front view of a gate cut device. The product and its gripping part are shown, (a) is a plan view of the state where the product is gripped, (b) is a side view thereof, and (c) is an enlarged view of the product taken out. Yes. It is a perspective view which shows an example of an integrally molded object, (a) is an example which equips four radial runners with four products, (b) has eight products molded into four radial runners. An example is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gate cut device 2 Integrated molding 2a Spool 2b Runner 2c Gate 10 Chuck unit 20 Work chuck member 21, 22 Chuck arm 21a, 22a Arc-shaped groove part 25 Direct acting member 30 Cutter 31 Fixed blade 32 Movable blade 34 Cylinder member (air hydro cylinder) )
35 Support Member 36 Heater 37 Leaf Spring 38 Spacer (Insulation Material)
39 Separator (Insulation)
41 Support body A Front end face G Gate part K Cut part P Product

Claims (6)

A chuck unit that includes a spool and a runner and that holds an integrally molded body having a product through a gate, and a work chuck member that grips the product among the held integral molded body, and a gripped product that is connected A gate cutting device comprising a cutter for cutting the gate being cut,
The work chuck member and the cutter are integrally assembled to the support body, and the cutter moves along the front end surface of the work chuck member on the side where the work chuck member grips the product. A gate cut device characterized by   The cutter includes a fixed blade and a movable blade having a heater, and a movable blade that moves in parallel to the fixed blade moves to cut the gate, and the front end surface is the fixed blade. The gate cutting device according to claim 1, further comprising a blade edge regulating portion that regulates a blade edge position of the blade and a blade edge guide portion that serves as a guide for the movable blade.   The product is a circular plastic molded product, and the work chuck member includes two left and right chuck arms and a linearly moving member that supports the two chuck arms so as to be able to come into contact with each other. Arc-shaped groove portions that are in contact with two points of the circular outer shape portion of the product are respectively disposed at the joint portion of the chuck arm to be gripped, and when the product is gripped by the arc-shaped groove portion to be joined, The front end surface of each chuck arm is made to be flush with the front end surface of the chuck arm member, and a part of the circular outer shape portion of the product is slightly exposed from the front end surface. The gate cut device according to claim 1 or 2, characterized by the above.   The movable blade is attached to the support member via a leaf spring and a spacer made of a heat insulating material, and is attached to be pressed by the blade edge guide portion when the movable blade approaches or separates from the fixed blade. The gate cut device according to claim 2 or 3, wherein the gate cut device is driven by a cylinder member while being energized.   The said cylinder member is an air hydro cylinder, The moving speed of the movable blade by this air hydro cylinder is a speed according to the softening degree of the said product softened by the heating of a heater. Gate cut device.   When the movable blade is at a position away from the fixed blade, the movable blade is located on a gentle slope provided at the lower portion of the blade edge guide portion and is in a state of being separated from the blade edge guide portion and abutting against a separator made of a heat insulating material. 6. The structure according to claim 2, wherein, during the cutting operation, the blade is brought into contact with the cutting edge guide part in the middle of the movement in the direction of the fixed blade, and the gate is cut by moving while being in contact. The gate cut apparatus in any one.

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