JPH11291302A - Gate cutting method and apparatus for injection molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the exclusion of manual gate removing work and the enhancement of the life of a blade by eliminating the entanglement of gate whiskers with a nipper or the like at a time of the cutting of the gate of an injection molded product and to compensate the lowering of the rigidity of a molded product grasping robot while ensuring a gate cutting position facilitating teaching and maintenance. SOLUTION: A hand 4 capable of grasping a molded product part is attached to a vertical drive arm 2 equipped with a mechanism revolvable to -90 deg.-, 0 deg.-and 90 deg.-positions. A molded product grasping robot 1 wherein the vertical drive arm 2 is attached to an orthogonal coordinates robot and a drive nipper 8 having a constant pressing force generating mechanism cutting the gate of a molded product 18 are arranged and a rearranging machine 19 for primarily holding the molded product 18 to the operation range of the molded product grasping robot is arranged and the gate generating surface of the molded product 18 grasped by the molded product grasping robot 1 is turned downwardly to cut the gate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate cutting method for cutting a gate of an injection-molded product, particularly a gate generated when a large variety of large-sized plastic pallets are manufactured.

[0002]

2. Description of the Related Art When a plastic product is manufactured by injection molding, a gate is present in the molded product, and it is necessary to cut the gate to separate the product.

Conventionally, after a molded product is taken out of a mold, it is conveyed by a conveyor or the like, and the gate is cut by an individual gate cutting device.

However, such a method requires a space for separately installing a gate cutting device, and a large change in layout of equipment and the like is required in an existing factory, and it is difficult to obtain the space. .

Therefore, there has been proposed an apparatus for cutting a gate in a state where a molded product is taken out of an injection molding machine. For example, JP-A-61-102226 discloses that a hand capable of chucking a sprue and a runner of a molded product and a mechanism for moving the hand up and down are attached to a rectangular coordinate robot.
A molded product take-out device for automatically cutting the gate of a plurality of molded products while interlocking with an injection molding machine by fixing an air nipper for performing gate cutting of the molded product in the operation area of the hand of the Cartesian coordinate robot. It has been disclosed.

Japanese Unexamined Patent Publication (Kokai) No. 63-239023 discloses a traveling body supported on an upper portion of a stationary platen of an injection molding machine and reciprocating on a main body frame, a holder supported by the traveling body, A cylinder for moving the holder up and down and a cylinder for moving back and forth, and a chuck attached to the holder and gripping a molded product, and a gate cut device facing the chuck is provided on a movable platen or a movable mold of an injection molding machine. An automatic ejection device for an injection molded article is disclosed.

[0007]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open Nos. 61-102226 and 63-2390 mentioned above.
In the molded article removing device disclosed in Japanese Patent Publication No. 23,
When the gate is cut, the gate generation surface of the molded product is not turned downward, so after cutting, a gate called an elongated thread-shaped mustache generated from the gate tip (hereinafter referred to as a gate mustache)
However, entanglement with the nipper, etc., necessitating manual gate removal work, and cutting with the gate beard entangled with the nipper and the hand, overloading the nipper blade and the hand and shortening the life of the nipper blade, ,
There is a problem that the equipment is damaged.

Further, in the above-mentioned conventional apparatus, since the gate is cut at the upper position where the rigidity of the upper and lower drive arms is high to stabilize the positional accuracy, there is a problem that teaching work and maintenance become difficult.

Further, a suction type hand is a general device for gripping a molded product. However, when gripping a large variety of large-sized molded products, a suction type hand is not suitable because a large suction force is required. Although there is a clamp system as a device for gripping a large molded product, the clamp system has the following problems since the molded product is bent. That is, Japanese Patent Application Laid-Open No.
In the apparatus disclosed in Japanese Patent Application Laid-Open No. 3-239023, when a gate cutting machine is fixed, a workpiece gripping robot is moved to a predetermined cutting position pre-teached, and a gate is cut, a molded product is negative with respect to the cutting machine. In the case where the gate is bent in the direction, uncut portions and the like are generated, and the gate cannot be cut accurately. Further, when the molded product is bent in the positive direction with respect to the cutting machine, an overload is applied to the molded product removal robot and the gate cutting machine, thereby causing equipment damage and shortening the blade life.

The problem to be solved by the present invention is as follows.

(1) The space in a factory can be effectively used and can be easily adopted in an existing factory.

(2) Eliminating the catch of the gate mustache on the nipper or the like, eliminating the manual gate removal operation, improving the service life of the blade, and securing the gate cutting position for facilitating teaching and maintenance while holding the molded product. Compensate for a decrease in robot rigidity.

(3) The gate can be cut with high accuracy by eliminating the gate uncut due to the bending of the work caused by adopting the work clamp method.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for cutting a gate of an injection-molded article according to the present invention comprises the steps of: In the method of cutting the gate of the injection-molded product by the drive type nipper disposed in the inside, the gate generation surface of the injection-molded product gripped by the molded product gripping robot is directed downward, and the gate is formed from below the gate. Is performed.

Further, according to the method for cutting a gate of an injection-molded product of the present invention, a hand capable of gripping a product part of the molded product is provided at the tip thereof.
Attach to a vertical drive arm provided with a mechanism that can rotate to 90-degree position, 0-degree position, and 90-degree position, and cut the gate of the molded product with a molded product gripping robot that has the vertical drive arm attached to a rectangular coordinate robot. A driving type nipper having a constant pressure pushing force generating mechanism is provided, and further, a holding machine for temporarily depositing the molded product in an operation range of the molded product gripping robot is arranged, and the gripper is gripped by the molded product gripping robot. Gate cutting is performed with the gate generation surface of the molded product facing downward.

[0016] The gate cutting device for an injection molded article of the present invention comprises:
A hand capable of gripping an injection molded product is attached to a vertical drive arm provided with a mechanism capable of pivoting to a -90 degree position, 0 degree position, and 90 degree position at the tip, and further, the vertical drive arm is mounted to a rectangular coordinate robot. A driving type nipper for cutting a gate of an injection molded product, and a holding machine for temporarily depositing the injection molded product, within a lower operation range of a hand of the molded product gripping robot, while forming a molded product gripping robot. It is characterized by being arranged.

In this apparatus, a vertical drive cylinder is provided on a frame, a mounting base is provided at a tip end of the cylinder via a damper, and a positioning stopper is provided on the mounting base.
A driving type nipper can be formed by providing a nipper blade having a driving source.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to embodiments shown in the drawings. FIG.
1 is a front view showing an embodiment of a gate cutting device of the present invention. In the figure, 1 is a molded article gripping robot constituted by an orthogonal robot, 2 is a vertical drive arm, 3 is a horizontal drive arm, 4 is attached to the lower end of the vertical drive arm 2, and is -90 degrees with the support shaft 5 as a fulcrum. , A hand capable of turning to a position of 0 ° or 90 °, 8 a driven air nipper having a constant pressure pushing force generating mechanism, 17 a movable type, 18 a product, and 19 a primary deposit of the molded product to the molded product gripping robot 1. 20 is a holding machine short side gripping cylinder, 21 is a gate scattering prevention panel, and 22 is a collection box for collecting gates and cutting pieces generated when the gates are cut.

As shown in FIG. 3, the hand 4 attached to the vertical drive arm 2 has a fixed side serving as a positioning reference, and a main gripping cylinder 6. Further, a short side gripping cylinder 7 is provided in the short side direction as well as gripping the molded product only by frictional force. By providing the short side gripping cylinder 7, the molded product 18 is
With this, the warpage at the time of clamping can be minimized. That is, when only the main gripping cylinder 6 is used, for example, when gripping a molded product of 80 kg, a gripping force of about 8 kg is required, and the warpage of the molded product 18 is generated by about 20 mm. However, by providing the short side gripping cylinder 7, the gripping force of the main gripping cylinder 6 needs only about 2 kilograms, and the warpage of the molded product can be suppressed to about 10 mm or less.

The drive type air nipper 8 having the constant pressure pressing mechanism has only one degree of freedom as shown in detail in FIG.
A vertical drive cylinder 10 is provided on the frame 9, a mounting table 12 is provided above a movable portion of the vertical drive cylinder 10 via a damper mechanism 11, and a nipper blade 14 driven by a nipper driving cylinder 13 is mounted on the mounting table 12. Has been installed. The damper mechanism 11 is formed of a spring steel formed in a spiral shape, and is configured to be sandwiched between the tip of the driving unit and the nipper blade 14. In the figure, 15 is a positioning stopper, and 16 is a linear guide of the vertical drive cylinder 10.

The holding machine 19 has a reference surface in the same direction as the hand 4 and has a holding cylinder 20 only in the short side direction as shown in FIG.

Further, the molded article gripping robot 1 is
Since the position of the gate differs depending on the specification 8, the information on the gate of the molded product is programmed in advance, so that the processing position suitable for the molded product of each specification can be appropriately set.

Next, a gate cutting method using the apparatus of this embodiment will be described with reference to FIG.

The molded product 18 ejected from the movable mold 17 is gripped while the hand 4 of the molded product gripping robot 1 is turned to the position of 90 degrees. At this time, by holding the molded product 18 while pressing it against the reference surface of the hand 4, the molded product 1
8 with respect to the hand 4.

Next, the hand 4 is temporarily retracted by the molded article gripping robot 1, and then the vertical drive arm 2 is raised to a position where the molded article 18 does not interfere with the injection molding machine. In this state, the gate 18a faces the direction of the hand 4.

In order to make the gate 18a the reverse side of the hand 4, the molded product 18 is once deposited in the transfer machine 19. At this time, the reference plane of the hand 4 and the reference plane of the holding machine 19 are set to be the same. That is, when the molded product 18 is delivered, the molded product 18 in the direction used as the reference of the hand 4 is transferred while being pressed against the reference surface of the holding machine 19.

Next, the hand 4 is turned to the position of -90 degrees, and the molded product 18 is gripped. Also in this case, the molded product 18 is positioned with respect to the hand 4 by pressing and gripping the molded product 18 against the reference surface of the hand 4. here,
The gate 18a is on the opposite side of the hand 4.

Next, the hand 4 is turned to the 0-degree position to turn the gate 18 downward. As shown in FIG. 2, with the gate beard 18b facing downward, the vertical drive arm 2 is lowered to a predetermined cutting position that has been taught in advance and stopped. At this time, a position (2 mm) where the tip of the gate 18 is above the blade surface of the nipper blade 14 is preferable. At that position, the gate mustache 18 b does not interfere with the nipper blade 14. If the lowering position of the vertical drive arm 2 is set so that the gate 18 is pushed between the blade surfaces of the nipper blade 14, the vertical drive arm 2
Is too fast, the gate 18a may interfere with the nipper blade 14. In this case, in particular, the nipper blade 14 may be overloaded, shortening the tool life of the nipper blade 14, and possibly damaging the nipper blade 10. Therefore, by stopping the hand 4 at a position where the tip of the gate 18a is above the nipper blade 14, the situation can be solved.

Next, the driving air nipper 8 is driven upward to a position where the positioning stopper 15 and the molded product 18 come into contact with each other. At this time, the gate 18a and the gate mustache 18b interfere between the blades of the nipper blade 14 (entangled).
Without causing the nipper blade 14 to rise. Positioning stopper 15 and nipper blade 14
Is mechanically determined, and the relative position between the molded product 18 and the nipper blade 14 is always constant regardless of the bending of the molded product 18. By adopting this drive type air nipper, in the actual machine, it is possible to absorb a maximum of about 15 mm of the warpage of the molded product, and to accurately and without overloading the nipper blade 14 and the vertical drive arm 2, the gate 18 a Can be cut.

If the molded product 18 is warped in the direction opposite to the driving air nipper 8, the driving air nipper 8 can follow the molded product 18 in accordance with the warpage of the molded product 18. In this case, In this case, the gate can be cut with high accuracy. Conversely, when the molded product 18 is warped toward the driving air nipper 8, the damping action of the damper 11 of the driving air nipper 8 acts, and an overload is applied to the driving air nipper 8 and the molded product 1. And maintain a constant pressing force. Further, despite cutting in a state where the vertical drive arm 2 is fully extended at the lower limit, that is, in a state where the positional stability accuracy is poor, the vibration is suppressed by pressing the drive type air nipper 8 against the molded article 8 to thereby suppress the vertical drive. The establishment time of the arm 2 can be shortened, and accurate gate cutting can be performed in a short time.

For example, if the position accuracy of the robot 1 for gripping a molded article is about 0.1 mm at the uppermost position of the vertical drive arm 2, it is about 2 mm at the lowermost position of the vertical drive arm 2. Position accuracy. what if,
When the molded product 18 of about 80 kilograms is lowered by 3 meters, it takes about 3 seconds to establish the molded product 18, but by pressing the main driving air nipper 8, the establishment time can be reduced to 1 second or less. .

In this state, by cutting the gate 18a by the nipper blade 14, the gate 18a
The gate beard 18b is collected in a predetermined gate collection box 22 without being entangled with the nipper blade 14.

In general, a large number of gates 18
a exists. For each gate 18a, the movement of the gripping robot 1, the pressing of the driving air nipper 8, and the cutting of the gate 18a are sequentially performed.
The molded product 18 is dispensed to a predetermined position in the collection box 22.

As described above, since the gate is cut with the gate beard 18b directed downward, the gate beard 18b is prevented from being entangled with the nipper blade 14 due to the influence of the gate beard 18b, eliminating the manual gate removal work and improving the blade life. Can be planned.

The relative position between the positioning stopper 15 and the nipper blade 14 is mechanically determined, and the position of the molded product 18 and the nipper blade 14 is always constant regardless of the bending of the molded product 18.

[0036]

As described above, according to the present invention, the following effects can be obtained.

(1) Conventionally, an extra space for a gate cutting device was required. However, the space can be saved by cutting the gate with a take-out machine, and the space in the factory can be effectively used. In addition, the gate cutting device of the present invention can be easily adopted in an existing factory,
It is possible to take out molded products by automation.

(2) By cutting the molded article downward, that is, with the gate mustache facing downward due to gravity, the catch of the gate mustache can be eliminated, and the manual gate removal operation can be eliminated and the blade life can be improved.

(3) Attaching the drive type nipper to the lower part facilitates teaching and maintenance.

(4) By adopting the gate cutting constant force pressing mechanism, the work establishment time can be shortened.

(5) Since cutting is performed at the lower limit of the lifting arm, a scattering prevention panel and a chute can be easily installed, and gate scattering can be prevented.

(6) Since the drive type nipper has a damper mechanism, the cutting tool follows and cuts with a constant force even if the molded product is warped in either direction.
Cutting can be performed with high accuracy without eliminating overload or leaving uncut portions.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a gate cutting device of the present invention.

FIG. 2 is a side view of a state in which a molded article gripping robot grips the molded article and cuts a gate using a driving air nipper.

FIG. 3 is an enlarged side view showing a state where a product is gripped by a hand.

FIG. 4 is a perspective view showing an embodiment of a driving air nipper.

[Explanation of symbols]

1 molded article gripping robot, 2 vertical drive arm, 3 horizontal drive arm, 4 hand, 5 spindle, 6 main gripping cylinder, 7 short side gripping cylinder, 8 drive air nipper,
9 Frame, 10 vertical drive cylinder, 11 damper, 12 mounting stand, 13 nipper drive cylinder, 14
Nipper blade, 15 positioning stopper, 16 linear guide, 17 movable type, 18 products, 19 reloading machine, 20 reloading machine short side gripping cylinder, 21 gate scattering prevention panel, 22 collection box

Claims (4)

[Claims] 1. A method for gripping an injection-molded article by a hand of a molded article gripping robot and cutting a gate of the injection-molded article by a driving type nipper arranged within an operation range of the hand of the robot. A gate cutting method for an injection-molded article, wherein a gate generation surface of the injection-molded article gripped by an article gripping robot is directed downward, and the gate is cut from below the gate. 2. A hand capable of gripping a molded product part is attached to a vertical drive arm provided with a mechanism capable of pivoting at -90 °, 0 °, and 90 ° positions at the tip, and the vertical drive arm is orthogonal. A molded article gripping robot attached to a coordinate robot and a drive type nipper having a constant pressure pushing force generating mechanism for cutting a gate of the molded article are disposed. Further, the molded article is primarily moved within an operation range of the molded article gripping robot. A method for cutting a gate of an injection-molded article, comprising: arranging a changeover machine for depositing the article, and performing a gate cut with a gate generation surface of the molded article gripped by the molded article gripping robot facing downward. 3. A hand capable of gripping an injection-molded product is attached to a vertical drive arm provided with a mechanism capable of pivoting at -90 °, 0 °, and 90 ° positions at the tip, and further comprising the vertical drive arm. In order to form a molded article gripping robot by attaching to a rectangular coordinate robot, and within the lower operation range of the hand of the molded article gripping robot, a driving type nipper for cutting a gate of an injection molded article, and a primary deposit of an injection molded article. A gate cutting device for an injection-molded article, characterized in that a transfer machine is provided. 4. A vertical drive cylinder is provided on a frame,
4. A drive type nipper formed by providing a mounting base via a damper at a tip end of the vertical driving cylinder, and providing a positioning stopper and a nipper blade having a driving source on the mounting base. An apparatus for cutting a gate of an injection-molded product according to the above description.