JPH0686086B2 - Mold clamping safety device for injection molding machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of a mold clamping safety device for an injection molding machine, which prevents movement of a movable plate due to a malfunction during mold opening.

[Prior Art] Conventionally, in this type of injection molding machine, there is
As disclosed in Japanese Patent No. 2, a lock rod is provided between the fixed plate and the movable plate, and by this lock rod, when the mold is opened by the backward movement of the movable plate, it is related to the opened / closed state of the safety door, A mold clamping safety device has been developed and put into practical use, which mechanically blocks the forward movement of the movable plate due to a malfunction unless the safety door is closed.

However, in such a conventional mold clamping safety device, the lock rod provided in the movable plate can be inserted into the through hole provided in the fixed plate, and the stopper plate can be opened and closed in the through hole. The cam plate with this stopper plate attached to the safety door side opens and closes in accordance with the opening and closing operation of the safety door, and when the safety door is in the open state, the through hole is closed with the stopper plate and the through hole of the lock rod The insertion is controlled so that the mold cannot be closed.

Further, when the lock rod is attached to the movable plate, the lock rod is opposed to the through hole of the fixed plate through the support portion of the movable plate so as to penetrate and supported, and the front and rear thereof are fastened with a pair of nuts. By adjusting the rotation, the protrusion length of the lock rod with respect to the through hole of the fixed plate at the time of mold opening is set to the mold opening stop position due to the change of the mold thickness that changes every time the mold is changed according to the shape of various products At present, the positioning is adjusted accordingly.

[Problems to be Solved by the Invention] Therefore, in the above-described conventional mold clamping safety device, when adjusting the protruding length of the lock rod, the nut is loosened manually by a spanner or the like to freely move the lock rod. West,
Since it is performed by tightening the nut again after positioning, not only is the positioning adjustment work of the lock rod extremely troublesome, but also a lot of time and effort is required for setup, etc. When a variety of products are used and molds are frequently changed to perform small-lot production, it becomes a major obstacle to production efficiency, and even if molds are automated, the effect is extremely large. There was such a problem.

[Object of the Invention] The present invention has been made under the above circumstances, and an object of the present invention is to provide an injection system capable of automatically performing positioning adjustment of a lock rod in a short time. It is to provide a mold clamping safety device for a molding machine.

[Means for Solving the Problems] In order to solve the above-described problems, the present invention has a fixed plate that supports a fixed mold and a movable plate that supports a movable plate facing the fixed mold on a machine base. In addition, a safety door is provided on the side of the mold opening / closing portion between the fixed plate and the movable plate so as to be openable and closable, and a through hole penetrating in the mold opening / closing direction in the upper part of the fixed plate, and the through hole is the safety door. In the mold clamping safety device, a stopper plate that is opened and closed by a cam plate provided on the movable plate is inserted into a support member on the movable plate toward the through hole. A rotary member having a screw shaft as a portion and having a gear wheel on the outer peripheral side, which is screwed with the screw shaft, is internally provided in the support member, and the rotary member is fixed outside the support member via the gear wheel. Reverse rotation driven servo motor or power A motor such as a loose motor and a rotation preventing member for the screw shaft are provided, and a proximity switch for confirming the tip position of the lock rod is provided near the stopper plate on the receiving member of the fixed plate.

[Operation] In the above configuration, the proximity switch can be used to confirm the tip position of the lock rod with respect to the stopper plate on the fixed board side, and the motor automatically determines the protruding length of the lock rod depending on whether the tip position is confirmed or not. Be adjusted. Further, the automatic adjustment is performed accurately in relation to the proximity switch because the motor is a servo motor or a pulse motor capable of controlling forward and reverse rotations, and the positioning adjustment work of the lock rod is completed in a short time.

[Example] Hereinafter, the present invention will be described in detail with reference to an illustrated embodiment.

As shown in FIGS. 1 and 2, reference numeral 1 in the drawings denotes a mold clamping device of an injection molding machine equipped with a mold clamping safety device according to the present invention, which includes a stationary plate 4 having a stationary mold 3 and a stationary mold 3. Opposing movable type 5
And a movable platen 6 supported by a tie bar 7 on the machine base 2. Safety doors 9 having upper and lower door rails 8 are provided on both side surfaces of the fixed platen 4 and the movable platen 6 corresponding to the mold opening / closing portions so as to be slidable along the mold opening / closing direction.

As shown in FIG. 3, a receiving member 10 is provided on the upper portion of the stationary platen 4. The receiving member 10 has a through hole 11 penetrating in the mold opening / closing direction and the through hole 11 is opened / closed. Is provided with a stopper plate 12 which is pivotally supported by a support shaft 12a so as to be tiltable and rotatable. The stopper plate 12 is provided with a cam plate 13 provided above the one safety door 9 so that the through hole 11 can be secured. When the safety door 9 is in the open state and the cam plate 13 is in the retracted position as shown in FIG. As shown by the arrow, the through hole 11 is rotated downward by its own weight to close the through hole 11.

On the other hand, a support member 14 facing the receiving member 10 is provided on the upper part of the movable plate 6, and a lock rod inserted into the through hole 11 is projected in the mold opening / closing direction on the support member 14. It is supported. As shown in FIG. 4, the lock rod 15 has a screw shaft 15a formed at a portion through which the support member 14 is inserted, and the screw shaft 15a is inserted into the support member 14 to form a pair of front and rear thrust bearings 16, 16, Bearings 17, 17 and 2
Along with the nut-shaped rotating member 19 having a gear 19a on the outer peripheral side that is rotatably provided via the disc springs 18 and 18, the lower outer periphery of the screw shaft 15a is axially aligned. Rotation is prevented by bringing the notched flat surface portion 15b into contact with a pair of guide rollers 20, 20 provided at the front and rear portions outside the support member 14, and the rotation member 19 is driven in forward and reverse rotation. It is supported so that it can be moved forward and backward in the mold opening and closing direction.

That is, the forward / reverse rotation drive control of the rotating member 19 is automatically performed by a driving motor 21 such as a servomotor or a pulse motor attached to the outside of the supporting member 14, and an output shaft of the motor 21. In the gear 23 provided in 22,
It has a structure in which the gear 19a of the rotating member 19 is meshed.

Numeral 24 is a proximity switch for confirming the tip position of the lock rod provided on the receiving member 10 of the fixed platen 4, which is located near the inside of the stopper plate 12.

Thus, according to the above configuration, as shown in FIGS. 5 and 6, when the safety door 9 is completely closed during normal molding, the stopper plate 12 is moved upward by the engagement of the cam plate 13. Since the through hole 11 provided in the receiving member 10 of the fixed platen 4 that has been pushed up is opened, the lock rod 15 is freely inserted into the through hole 11 as the movable platen 6 moves back and forth, and the lock release state is obtained. To maintain. In this state, if you want to suspend the operation temporarily due to defective discharge of the product or runner, etc., the safety door 9
By opening an electric and hydraulic interlock system (not shown), the mold opening and closing is stopped, and when the safety door 9 is opened, the cam plate 13 is stopped by the stopper plate.
The stopper plate 12 is dropped and rotated by its own weight to close the through hole 11, thereby preventing the lock rod 5 from being inserted into the through hole 11 and making it unable to move forward and backward.
Even if an electrical or hydraulic interlock system (not shown) does not operate, the movable platen 6 is prevented from moving back and forth to ensure the safety of the mold or the operator.

In addition, after adjusting the protrusion length of the lock rod 15 according to the die thickness after the die replacement, first of all, when the lock rod 15 is closed by the proximity switch 24 at the die opening stop position. Proximity switch confirms the position of the tip
When 24 senses the tip of the lock rod 15 and is in the “ON state”, the position of the lock rod 15 is too far forward, and therefore the output shaft 22 of the motor 21 is driven, for example, in the “reverse” direction to drive the gear. By rotating the rotary member 19 clockwise through “23” through 23, the lock rod 15 is retracted in the mold opening direction,
After turning the proximity switch 24 to "OFF",
By driving the output shaft 22 of the motor 21 in the “forward” direction and rotating the rotating member 19 in the counterclockwise direction “reverse”, the lock rod 15 is advanced in the mold closing direction, and the proximity switch 24 is set to the “ON state”. It is performed by stopping at the position.

On the contrary, at the time of confirmation, when the proximity switch 24 is in the “OFF state”, the position of the lock rod 15 is too rearward, so that the output shaft 22 of the motor 21 is driven in the “forward rotation”, This is performed by rotating the rotating member 19 "counterclockwise" in the counterclockwise direction to move the lock rod 15 forward in the mold closing direction and stop the proximity switch 24 at the "ON" position.

Incidentally, the example of the positioning of the lock rod 15 as described above is an indirect setting means when the mold opening stop position is unknown, but the mold opening stop position is set in advance in various molds such as a storage device. If stored according to the setting conditions, the motor 21 is automatically rotationally controlled so that the lock rod protrusion distance corresponds to the mold opening stop position, and the position is directly set. Well, the position setting at this time should be done by turning ON the setting switch, or
It is also possible to make it automatically by a program before the start of molding, and the selection is arbitrary.

EFFECTS OF THE INVENTION As described above, according to the present invention, the support portion of the lock rod of the required length, which projects from the support member on the movable plate toward the through hole provided in the upper portion of the fixed plate, is used as the screw shaft. , A servo motor for internally rotating a rotating member having a nut-shaped gear on the outer peripheral side, which is screwed with the screw shaft, on the outer side of the supporting member, and driving the rotating member forward and backward through the gear on the outer side of the supporting member. Alternatively, a motor such as a pulse motor and a rotation preventing member for the screw shaft are provided, and a proximity switch for confirming the tip position of the lock rod is provided near the stopper plate on the receiving member of the fixed plate. The lock rod can be easily positioned by exchanging the mold by rotating the rotating member with the motor. In addition, since a servo motor or pulse motor that can easily control forward / reverse rotation is adopted as a drive motor for the rotating member, the protrusion length of the lock rod is adjusted by rotating the motor, but the positional accuracy is high, and Positioning is performed by checking the tip position of the lock rod with a proximity switch provided near the receiving member of the fixed plate, so positioning work can be completed in a short time.
There is an advantage that the lock rod can be positioned automatically and surely only by operating the motor after the die replacement.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a mold opening state and a safety door opening state in a mold clamping device of an injection molding machine equipped with the mold clamping safety device according to the present invention, and FIG. Front view of the mold open state and the open state of the safety door, FIG. 3 is a sectional view showing the stopper mechanism of the fixed platen side, FIG. 4 is a sectional view showing the support state of the lock rod of the movable platen side, and FIG. Similarly, FIG. 6 is a side view showing a mold clamping state and a safety door closed state in the mold clamping device, and FIG. 6 is a front view showing a mold clamping state and a safety door closed state in the mold clamping device. 1 ... Mold clamping device, 2 ... Machine base, 3 ... Fixed type, 4 ... Fixed type, 5 ... Movable type, 6 ... Movable type, 8,8 ... Door rail, 9 ... Safety door, 10 ... Receiving member, 11 ... Through hole, 12 ... Stopper plate, 13 ... Cam plate, 14 ... Support member, 15 ... Lock rod, 15a ... Screw shaft, 19 ... Rotating member, 19a ... … Gear, 21 …… motor, 22 …… output shaft, 23 …… gear.

Claims (1)

[Claims] 1. A side surface of a mold opening / closing portion between a fixed plate and a movable plate, the fixed plate supporting the fixed mold and a movable plate supporting a movable plate facing the fixed mold on a machine base. A safety door is provided so as to be openable and closable, and a through hole that penetrates in the mold opening and closing direction is provided in the upper part of the fixed plate, and a stopper plate that opens and closes the through hole by a cam plate provided on the safety door. In a mold clamping safety device in which a lock rod having a required length is inserted through a supporting member on a movable plate and protrudes, a supporting portion of the lock rod is a screw shaft, and a nut shape screwed with the screw shaft. And a motor such as a servomotor or a pulse motor for driving the rotating member in the forward and reverse directions through a gear on the outside of the supporting member, and the screw is provided inside the supporting member. Provided with a shaft rotation blocking member A mold clamping safety device for an injection molding machine, wherein a proximity switch for confirming a tip position of the lock rod is provided on a receiving member of the fixed plate in proximity to a stopper plate.