JPH0345308A - Foreign matter detecting device of mold breaking and clamping mechanism - Google Patents

Abstract

PURPOSE:To enable in a moment especially detection of a foreign matter in a vertical injection molding machine, by a method wherein the first and second sensors detect respectively a moving position of a driving device and that of a conversion device and logical control is performed with output signals of both the sensors. CONSTITUTION:In the case where there is no foreign matter between mold members, a spring 34 in stroke detecting unit 18a is not bent with an extruding action of a cylinder 15, OFF signals are sent with both the first and second sensors 18, 48 and normality of elevating action of a bottom force 6 is detected in a logical circuit. When there is a foreign matter 51 on a bottom force 6, the spring 34 of the stroke detecting unit 18a beings to bend from a point of time when the foreign matter 51 abuts against a top force 54, an ON signal is sent from the first sensor 18. However, since a cam plate 8 is not yet moved to a position where light from the second sensor 48 shines upon the same, the OFF signal is sent from the second sensor. Abnormality in a rising action of the bottom force 6 is decided in the logical circuit, the cylinder is suspended immediately and at the same time an alarm is emitted by an alarm.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a foreign object detection device for a mold opening/closing mechanism in an injection molding machine, particularly a vertical injection molding machine.

[Prior Art] Conventionally, molded products are manufactured by kneading molding materials such as plastics into a molten state in a heating cylinder and injecting the molten material into a molding die provided with an injection port. In such injection molding machines, there are two main types: one in which the heating sill is configured horizontally, and one in which the heating sill is configured vertically.

[Problems to be Solved by the Invention] In a horizontally configured injection molding machine, the mold is opened and closed in the horizontal direction, so even if there is an ejection error during automatic ejecting of molded products, many molded products can be removed. Since it does not fall and remain in the mold, the mold members will not be damaged even if the mold is clamped. However, in a vertical injection molding machine, the mold is opened and closed vertically, so if there is a mistake in ejecting the molded product, it will remain in the mold without falling out of the mold. The mold member may be damaged during mold clamping. Furthermore, in the case of a vertical injection molding machine, there is a risk that foreign matter such as pieces of the molded product remaining during molding will mix with the injected resin and continue molding as is.

Therefore, conventionally, to detect foreign objects inside the mold,
For example, a mold clamping stroke completion detection sensor and a timer are used to first perform the mold clamping operation at low pressure, and if the mold clamping stroke completion signal is not issued within a predetermined time, it is determined that there is a foreign object and the main mold clamping operation is performed at high pressure. However, the problem is that it takes time to recognize the foreign object after it is caught between the molds, and mold damage may be unavoidable even with low-pressure mold clamping operations. was there.

The present invention was made in view of the above circumstances, and
It is an object of the present invention to provide a foreign object detection device for a mold opening/closing mechanism that is particularly suitable for a vertical injection molding machine and can instantaneously detect foreign objects with a simple configuration.

[Means for Solving the Problems 1] In order to solve the above-mentioned problems, the foreign object detection device for the mold opening/closing mechanism of the present invention includes a first sensor that detects the moving position of the driving means that opens and closes the mold member; a converting means for converting the drive of the driving means into an opening/closing movement of the mold part lever; a second sensor for detecting the moving position of the converting means; and the first and second sensors.
It has a logic circuit that logically controls signals from the sensor,
The present invention is characterized in that foreign matter is detected based on the output signal of the logic circuit.

[Effect]

In the above configuration, the drive of the drive means for opening and closing the mold member is converted into an opening/closing operation of the mold member by the conversion means. Therefore, when the driving means is activated, it is possible to detect an abnormality in the opening/closing operation of the mold member by determining whether or not the converting means performs a predetermined operation of opening and closing the mold member in response to the actuation of the driving means.

In such a configuration, the first sensor detects the moving position of the driving means, and the second sensor detects the moving position of the converting means, so the signals of both sensors are logically controlled. It is determined from the output signal that there is an abnormality in the opening/closing operation of the mold member.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1(a) is an overall perspective view of a mold opening/closing mechanism according to an embodiment of the present invention, and Fig. 1(b) shows the internal structure of a cylinder stroke detection unit installed in the device shown in Fig. 1 (Sat). The cross-sectional view shown in FIG. 2(a) is taken along the line A-A in FIG. 1(a).
2(b) is a configuration diagram of the protrusion unit shown in FIG. 1(a) etc., and FIGS. 3(a) and (b)
1(a) is a side view taken from the direction B-B in FIG. 1(a), and is a diagram showing the up-and-down movement of the device shown in FIG. 1(a), and FIGS. 4(a) to (c) 5 is a diagram showing signals from the first sensor and the second sensor during mold opening/closing operations by cylinder drive, and FIG. 5 is a logic circuit diagram for logically controlling the signals according to FIG. 4.

In FIGS. 1(a) and 2(a), the injection cylinder drive l-3 is connected to the support member 11. The nozzle 3a at the lower end of the injection cylinder unit 3 is inserted into the opening 2a of the upper mold mounting plate 2, and the nozzle 3a of the injection cylinder unit 3 is inserted into the opening 2a of the upper mold mounting plate 2. It is pressed into contact with the runner artificial part 5a of the upper mold 5 which is fixed to the lower part of the mold 2.

Below the upper mold 5, two supporting bodies 1 are arranged side by side with an interval between them, and guide rails 4 are attached along the upper ends of each of the supporting bodies 1. A linear bearing 7 was slidably fitted onto each of these guide rails 4, a cam plate 8 was fixedly supported on the linear bearing 7, and each cam plate 8 was disposed facing each other on the two support bodies 1. has been in a state.

Each of the cam plates 8 is provided with a cam groove 10 having a shape as shown in FIGS. 3(a) and (1).

This cam groove includes a relatively long sloped portion 10a, a lower end portion 10b formed near the lower end of the sloped portion, and a lower end portion 10b formed approximately horizontally.
An upper end portion 10c having a slope angle Oa gentler than Oa is continuously formed.

Cam followers 13 are fixed to both sides of the lower die 6, and each cam follower is slidably fitted into a cam groove 10 of the cam plate 8. Note that the cam follower 13 is not the lower mold 6, but
It may also be provided on the lower die mounting plate 12. The cam plate 8 also has an arm 1 that connects the cam plate 8 in the direction along the guide rail 4.
A horizontal drive cylinder 15 is connected to the arm 17, and each cam plate 8 can integrally move on the guide rail 4 by horizontal drive of this cylinder]5.

Between the mutually opposing cam plates 8, there are
As shown in Figures (a) and (1), the lower mold 6 and the lower mold mounting plate 12 that holds the lower mold are supported by a guide shaft 14 via a guide bush 14a so as to be movable up and down.

A support plate 30 for lateral load bearing is provided on the side of the lower mold mounting plate 12, and a cam follower 31 is pivotally supported by a pin 32 provided on the side of the lower mold mounting plate 12 with respect to this support plate. are brought into contact with each other, and bear the lateral load when the cylinder 15 is horizontally driven when the lower die 6 is raised and lowered.

With such a configuration, when each cam plate 8 is horizontally driven integrally by the drive of the cylinder 15, the cam follower 13
can move the lower die 6 up and down by following the cam groove 10. Then, as shown in FIG. 3(b), the lower mold 6 is replaced by the upper mold 5.
When trying to contact the cam follower 13, the cam groove 10
The cam follower] 3 is located near the boundary between the inclined part 10a and the upper end], and the upper end 1. Mold clamping can be performed while being followed by Oc.

A stroke detection unit 18a of the cylinder 15 is provided between the rod 15a of the cylinder 15 and the arm 17. As shown in FIG. 1(b), the six detection units are attached to the arm 17 with a lid 36 bolted through a hole 37 and fastened to a cylindrical body 35 with a bolt 39. A locking plate 33 fixed to the end of the cylinder rod 15a is slidably provided inside, and the lid body 36 and the locking plate 3
A spring 34 is interposed between the three. The spring 34 has such strength that it does not bend when the lower mold 6 is raised and lowered by the extrusion operation of the cylinder 15, but it bends when there is an extrusion operation after the completion of mold closing or a clogging operation and a mold clamping operation. Further, on the side of the end of the cylinder rod 15a side of the cylinder body 35, there is an optical sensor (hereinafter referred to as a first The tip of an optical fiber 18b for transmitting and receiving light from a sensor 18 is connected. The light from the first sensor 18 is
When the spring 34 is not deflected, it hits the locking plate 33 and an OFF signal is generated, and when the spring 34 is deflected, it hits the cylinder rod 15a and an ON signal is generated.

On the other hand, as shown in FIG. 1(a), an optical sensor (hereinafter referred to as a second sensor) 48 for detecting the movement position of the cam plate 8 is provided on the side of the cam plate 8.

The second sensor 48 is installed at a position where the light from the second sensor hits the cam plate 8 when the cylinder 15 is driven horizontally and the cam plate 8 moves to a position where the lower die 6 comes into contact with the upper die 5. When the light emitted from this sensor does not hit the cam plate 8, an OFF signal is generated, and when the light hits the cam plate 8, an ON signal is generated.

The signals from these first and second sensors are logically controlled by a logic circuit shown in FIG. 5 to determine whether the relationship between the stroke of the lower mold 6 and the cylinder stroke is normal or not. When it is determined that an abnormality has occurred, such as an abnormality, safe drive control is performed to immediately stop the cylinder drive.

Here, the first sensor 18 and the second sensor 4 shown in FIG.
8 and the logic circuit shown in FIG. 5,
Abnormality determination and detection of whether or not there is a foreign object in the mold will be explained.

In the logic circuit shown in FIG. 5, when the signals from the first sensor and the second sensor are both OFF, it is determined that the lower mold 6 is moving up and down normally, and when both are ON, the mold clamping is performed normally. The judgment being made is made, but when different signals are emitted from the first sensor and the second sensor, the judgment that an abnormality has occurred is confirmed.

FIG. 4(a) shows the state in which the lower die 6 is raised when there is no foreign matter between the die members. At this time, the pushing action of the cylinder 15 causes the spring 34 in the stroke detection unit 18a to
Without deflecting, the first sensor 18 issues an OFF signal, and at this point the cam plate 8 has not yet moved to the position where it is exposed to the light from the second sensor 48, so the second sensor issues an OFF signal. . When the OFF signal is emitted from both the first and second sensors in this manner, the logic circuit shown in FIG. 5 detects that the lifting and lowering operations of the lower die 6 are normal.

FIG. 4(b) shows the state when the lower mold 6 is raised when there is a foreign object 51 between the upper and lower molds. At this time, from the time when the foreign object 51 in the lower die 6'' comes into contact with the upper die 54, the spring 34 of the stroke detection unit], 8a starts to bend, and the first
The sensor emits an ON signal, but at this point, the cam plate 8 has not yet moved to the position where it is exposed to the light from the second sensor 48, so the second sensor emits an OFF signal.

In this way, when the second sensor 48 generates an OFF signal even though the first sensor 18 generates an ON signal, the logic circuit of FIG. It is determined that When an abnormality is determined, the cylinder is immediately stopped and an alarm is issued at the same time.

FIG. 4(C) shows a state in which the lower mold 6 has risen until it comes into contact with the upper mold 5 and the mold has been clamped. At this time, the spring 34 of the stroke detection unit 18a is deflected, the first sensor 18 issues an ON signal, the cam plate 8 moves according to the horizontal drive of the cylinder 15, and the signal from the second sensor is transmitted to the cam plate 8. The ON signal is generated.

When ON signals are emitted from both the first and second sensors in this manner, the logic circuit shown in FIG. 5 determines that mold clamping has been completed.

As described above, according to the foreign object detection device for the mold opening/closing mechanism in this embodiment, the first sensor 18 detects the stroke of the cylinder 15, and the second sensor 48 detects the movement of the cam plate 8 driven by the horizontal drive of the cylinder 15. Since it is configured to detect the position, it can be determined that there is an abnormality in the opening/closing operation of the mold member by logically controlling the output signals of the first sensor 18 and the second sensor 48.

Furthermore, in this device, a rack gear 9 is attached horizontally to the outer surface of the cam plate 8 on one side (the near side in FIG. 1). Further, between the support body 1 and the upper die mounting plate 2, there are rotary shafts 20 each having a pinion gear 21, which fits into the gear 9 of the cam plate 8, fixed with a key 22, and are rotatable and vertically movable via bushes 23. It is provided. A coil spring 24 is interposed between the pinion gear 21 of the rotating shaft 20 and the support body 1, and the rotating shaft 20 is urged upward by this spring. Also, the pinion gear 21 of the rotating shaft 20
An auto hand arm 25 having a finger 21M attached to the lower tip thereof is fastened to the top with a bolt 26. The auto hand arm 25 is rotated by the rotation of the rotating shaft 20, and the finger 27 at the tip can be moved between the upper and lower molds 5 and 6. The upper end of the rotating shaft 20 passes through the upper die mounting plate 2, and a vertically moving cylinder 28 having a thrust bearing unit 29a at its tip is in contact with the upper end. Therefore, the autohand am 25 has the cylinder 2
The rotating shaft 20 is moved up and down by the vertical drive of 8 and the coil spring 24 to raise and lower the cylinder] 5
The horizontal drive causes the rack 9 to rotate by rotating the pinion gear 21.

Further, a stopper ring 29b is slidably fitted on the outer periphery of the rotating shaft 20 of the upper die mounting plate 2, and the vertical movement cylinder 28
The downward stroke of the rotary shaft 20 due to the vertical drive of the rotary shaft 20 is determined.

With this configuration, the downward stroke of the auto hand arm 25 can be changed by retracting the rod of the cylinder 28 and pushing down the rotating shaft 20 against the coil spring 24, thereby changing the thrust bearing unit 29a and the rotating shaft 2.
This can be easily done by opening a space between the ends of the stopper ring 29ib and changing the stopper ring 29ib to one with a different height.

Note that the ejecting unit 40 provided on the F side of the lower die 6
is a pin 4 that projects the molded product 50 housed in the lower mold 6.
1 and a unit I for supporting the pin 41 and pushing up the plate 42, which includes an upper rod 43, a lower rod 46, and a unit I. Male threaded part 44 and female threaded part 4 inside lower mold rod 46
6a, a nut 45, a positioning portion 46c, and a stopper 461), and the entire length of the protrusion unit 40 (from the upper rod 43 to the stopper 46b) can be adjusted. Reference numeral 47 denotes a protrusion unit holder which detachably supports the protrusion unit, has a hole through which the positioning portion 46C of the protrusion unit is inserted, and holds the protrusion unit. The protruding unit 40 is attached to the lower die mounting plate 1
It is inserted through the through hole of No. 2. With this configuration, the lower die 6 moves downward by a fixed stroke relative to the ejecting unit 40, the ejecting bottle support plate 42 in the lower die 6 comes into contact with the tip of the upper rod 43 of the ejecting unit 40, and continues downward until the final stroke. The mold 6 is lowered to allow the molded product 50 to protrude when the molded product is taken out.

Next, the upper and lower molds 5 of the mold opening/closing mechanism configured as described in 2.
．． Fig. 3 (a
) and (b).

In addition, for convenience of explanation, some parts of FIGS. 3(a) and (1)) are omitted or shown with dotted lines (for example, the cam plate 8).
It is. Further, the first hand 25 for taking out the molded product and the like are omitted because they complicate the illustration.

FIG. 3(a) shows a state in which the cam follower 13 is fitted into the lower end portion 10b of the cam groove 10. At this time, the lower die 6 is at the lowest position. From this state, when the cam plate 8 is pushed out by the cylinder 15, the cam follower 13 moves into the cam groove 10.
The lower mold 6 rises as it moves upward along the inclined portion 10a, and the lower mold 6 comes into contact with the upper mold 5 as shown in FIG. It is located in Furthermore, when the cylinder 15 continues to push out the cam plate 8, the cam groove 1
The inclination angle θ provided at the upper end portion 10c of 0 can increase the cylinder output by a wedge effect to clamp the −L lower mold 5.6. Next, the molten molding resin of the injection cylinder unit 3 is injected into the upper and lower molds 5.6.

When taking out the molded product 50, when the cam plate 8 is pulled back from the above state by the cylinder 15, the cam follower 13 moves into the cam groove 1.
3 (a) again while following the inclined part 10a of 0 downward.
), it is in a state where it is fitted into the lower end portion 101) of the cam groove 10. At this time, the lower mold 6 is lowered by the action of the cam follower 13, and the molds are opened between the upper and lower molds 5.6. On the other hand, as the cam plate 8 moves, the rotating shaft 20 rotates, and the automatic hand 25 moves between the open upper and lower molds 5.6. At this time, the molded product 5 is removed by the ejecting unit 40 as described above.
0 has been ejected, the cylinder 28 is lowered until the thrust bearing unit 29a contacts the stopper ring unit 1-29b, thereby lowering the rotating shaft 20 and moving the finger 27 at the tip of the auto hand arm 25 to the lower mold. 6 and grips the molded product 50 with the jaws 27a.

Next, the cylinder 28 is retracted, and the auto hand arm 25
When the cam plate 8 is pushed out by the cylinder ]5, the auto hand arm 25 rotates and is retracted from between the upper and lower molds 5.6, and the lower mold 6 rises again, as shown in FIG.
As shown in b), the upper and lower molds 5.6 are brought into contact. At this time, the auto hand arm 25 is completely retracted from between the upper and lower molds, and during this time, the cylinder 28 is further driven up and down, and the finger 27 is moved to a finished product storage area (not shown) provided outside the mold to take out the molded product 50. can be placed in

Further, at the time when the foreign object detection means is activated, the cylinder output is not directly transmitted to the cam plate 8, and when the spring 34 is completely bent and the support member 11 comes into contact with the locking plate 33, the cylinder output is directly transmitted to the cam plate 8. 8, it is configured to generate a strong mold clamping force, so even if a foreign object is caught, it can be detected when only a small force is generated between the two lower molds.
It is possible to instantly switch to safe drive control, which increases the effectiveness of preventing mold damage.

The foreign object detection device for the mold opening/closing mechanism according to the present invention can be applied to vertical injection molding machines as well as horizontal injection molding machines, but it is particularly effective in vertical injection molding machines where foreign objects tend to remain between mold members. It is possible to perform a foreign object detection function between mold members.

[Effects of the Invention] As explained above, in the foreign object detection device for the mold opening/closing mechanism of the present invention, the first sensor detects the moving position of the driving means, and the second sensor detects the moving position of the converting means. Therefore, when the driving means is activated, it is determined whether or not the converting means performs a predetermined operation of opening and closing the mold member in response to the actuation of the driving means, and this is logically controlled by the output signals of both sensors. This allows it to be determined that there is an abnormality in the opening/closing operation of the mold member.

Therefore, according to the foreign object detection device for the mold opening/closing mechanism of the present invention,
Even if foreign matter remains in the upper and lower molds, such as molded products that failed to be ejected or fragments of molded products from the previous process, the first and second
Since an abnormality in the mold opening/closing mechanism is automatically detected based on the output signal of the sensor, the mold will not be damaged during mold clamping, especially in a vertical injection molding machine.

[Brief explanation of drawings]

FIG. 1(a) is an overall perspective view of a mold opening/closing mechanism of a vertical injection molding machine according to an embodiment of the invention, and FIG.
2(a) is a side view taken from the direction A-A in FIG. 1(a); FIG. 2(b) is a sectional view showing the internal structure of the cylinder stroke detection unit attached to the device shown in L).
is a configuration diagram of the protruding unit shown in FIG. 1(a) etc., and FIGS. 3(a) and (b) are B in FIG. 1(a).
-A side view from the direction B, showing the vertical movement of the device shown in FIG. 1(a); FIGS. 4(a) to (C);
) is a diagram showing the signals of the first sensor and the second sensor during the mold opening/closing operation by cylinder drive, and FIG. 5 is a logic circuit diagram for logically controlling the signals according to FIG. 4. 2...Upper die mounting plate 3...Injection silling unit 4...Guide rail 5...Upper die 6...Lower die 8...Cam plate 9...Rack gear 10...Cam groove 0 0b... Lower end of the cam groove Oc... Upper end of the cam groove 1... Support member 2... Lower die mounting plate 3... Cam follower 4... Lower die lifting guide shaft 5 ...Horizontal drive cylinder 8...Optical fiber sensor for cylinder stroke detection (first sensor) 8a...Cylinder stroke detection unit 8b.
... Optical fiber O ... Rotating shaft 21 ... Pinion gear 5 ... Auto hand 8 ... Vertical movement cylinder 4 ... Spring 8 ... Optical sensor for detecting the movement position of the cam plate (No. 2 sensor) 1...Foreign object

Claims (1)

[Claims] (1) A first sensor that detects the moving position of a driving means that opens and closes the mold member, a converting means that converts the drive of the driving means into an opening and closing movement of the mold member, and a first sensor that detects the moving position of the converting means. A mold opening/closing mechanism comprising a second sensor and a logic circuit that logically controls signals from the first and second sensors, and detects a foreign object based on an output signal of the logic circuit. foreign object detection device.