JPH0122139B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an injection molding apparatus equipped with a safety device that locks the mold closing operation of a movable plate when a safety door is open.

(Prior Art) Generally, an injection molding apparatus is equipped with a safety door 1 shown in FIG. 2 to prevent an unexpected accident from occurring during mold clamping.

The safety door 1 is installed on the side of the movable plate 2 and the fixed plate 8, and runs on a rail (not shown) extending along the moving direction of the movable plate 2.

However, unless this safety door 1 is closed when the mold D is clamped, its effect cannot be achieved.

Therefore, when the safety door 1 is not closed, an interlock device is activated using hydraulic pressure or electricity to prevent the mold clamping operation, but consideration has been given to the case where the interlock device does not operate. Generally, a mechanical locking device is also used.

3, 4 and 5 show a conventional mechanical locking device, in which a bracket 4 is attached to the top surface of a movable plate 2 via bolts 3.
A safety bar 6 is installed in the sliding hole 5 of this bracket 4.
is built in so that it can slide freely.

Here, the bolts 7, 7 are used to fix the safety bar 6 to the movable plate 2 by protruding it to the fixed plate 8 side by a predetermined length.

A bracket 9 is also attached to the top surface of the fixed plate 8 facing the movable plate 2 at a distance. It consists of a pair of guide parts 12 having sliding holes 11.

A support rod 13 is protruded from the mounting portion 10, and a lock plate 1 is connected to the support rod 13 via a shaft 14.
5 is rotatably attached. A roller 16 provided at one end of the lock plate 15 is in contact with the lower surface of a cam 17 attached to the upper front end of the safety door 1. The lower surface of this cam 17 has a straight part 17a and an inclined part 17b, and the safety door 1
When the roller 16 moves to the left in the figure, the roller 16 moves to the inclined part 17b, and the lock plate 15 moves to the third position.
Rotate in the direction of arrow P from the state shown in the figure.

As a result, the safety bar 6 moves to the left in the figure during the opening operation of the mold, so it is not affected by the position of the lock plate 15, and even if the safety door 1 is opened at any position, the safety bar 6 can be opened without any problem. The mold opens and the operation ends. On the other hand, during mold closing operation, safety bar 6
moves to the right in the figure, so when the safety door 1 is opened, the passage through which the safety bar 6 enters the sliding hole of the guide part 12 is blocked by the lock plate 15, so the safety bar 6 hits the lock plate 15. The movable plate 2 is stopped at the moment of contact.

(Problems to be Solved by the Invention) However, in such a safety device using a lock plate and a cam, the mold clamping stop operation position is determined by the protrusion length of the safety bar.

Therefore, even if the safety door is opened after the safety bar is inserted into the guide part during the mold closing operation, the lock plate will rest on the safety bar.
Unable to block the safety bar passage,
There was a drawback that the mold closing operation continued.

Therefore, conventional safety devices can only operate at a fixed position, such as at the mold clamping start position.

Also, the safety bar depends on the thickness of the mold.
In order to adjust the length of the protrusion, when replacing the mold, it is necessary to decide at what point the lock plate should hit the safety bar each time, which is a tedious task.

In order to solve the above problems, the present invention eliminates the need to adjust the safety device even if the thickness of the mold changes, and also ensures that the safety device is activated when the safety door is opened regardless of the position of the movable plate. The purpose is to provide an injection molding device.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an injection molding apparatus equipped with a safety door that can close the gap between a movable plate and a fixed plate from the side. A rotating shaft is attached via a one-way clutch, and a second clutch is provided between the annular body screwed onto the rotating shaft and a housing fixed to the main body of the device to connect and disconnect the annular body and the housing; Further, the annular body and the housing are connected to each other by connecting a second clutch to the housing when the safety door is opened, and disengaging the second clutch when the safety door is closed. Therefore, a transmission member is installed to disconnect the annular body from the housing, and the one-way clutch allows the rotary shaft to rotate only when the mold is opened.

(Function) Since the present invention has the above configuration, when the safety door opens regardless of the position of the mold during the mold opening/closing operation, the second clutch is actuated by the transmission member and the base of the mold clamping cylinder is closed. and the sleeve become one. For this reason, the rotating shaft, which had previously simply rotated idly together with the sleeve, now moves forward and backward while rotating with respect to the base due to the threaded engagement of the nut member.

However, the movement of the rotating shaft is restricted by a one-way clutch provided on the movable plate.

In other words, the one-way clutch locks the rotating shaft during the mold closing operation and frees the rotating shaft during the mold opening operation. As a result, even when the mold closing operation is in progress,
Immediately after the safety gate is opened, a second clutch is actuated to stop the movable plate.

On the other hand, during the mold opening operation, even if the safety door is opened, the rotating shaft idles, so the movable plate can be moved back to open the mold.

(Example) Embodiments of the present invention will be described based on the drawings.

In FIG. 1, the injection molding apparatus of this embodiment is as follows:
A clamping gram 21 in a mold clamping cylinder 20 is driven by hydraulic pressure to move the movable plate 2 in the left and right directions in the figure.

A one-way clutch 2 is attached to the upper end of the movable plate 2.
3 is installed inside, and one end of a rotating shaft 24 formed with a ball screw is inserted into the one-way clutch 23. On the other hand, the mold clamping cylinder 2 fixed to the device body
A housing 25 is attached to the housing 25, and a multi-plate friction clutch 26 is installed inside the housing 25, and a rotating shaft 24 is screwed into the clutch 26 via a ball screw nut 27 as an annular body. . Thereby, the rotating shaft 24 comes to be arranged parallel to the safety door 1.

The one-way clutch 23 is a cam clutch that releases or connects the clutch depending on whether or not the cams engage with the inner and outer rings, and is locked when the rotating shaft 24 rotates to the left when viewed from the movable plate side (during mold closing operation). It is installed so that it becomes free when rotated clockwise (during mold opening operation).

The friction clutch 26 generally includes a sleeve 28 that is rotatable relative to the housing 25 and a clutch portion 29 that connects the housing 25 and the sleeve 28. The sleeve 28 is the housing 2
A bearing 30 is interposed between the bearing 5 and the ball screw nut 27, and a ball screw nut 27 can be integrally assembled therein.

The clutch portion 29 is provided on the outer circumference of the sleeve 28 and is connected to the sleeve 28 via a key 31.
A plurality of grooves 32a, . . . are equally divided in the inner ring 32 that is integrated with the housing 25, and the rotation of the L-shaped links 33, .
Or, it has a structure in which a pair of friction plates 34, 34, each fixed to either of the sleeves 28, are brought into contact with each other or separated from each other.

Components for this purpose include a slidable annular pusher 35 having a separate recess, a stopper 36 that connects the housing 25 and one of the friction plates 34, and a claw 33a of the L-shaped link 33 that connects the other. Friction plate 3
A push plate 37 that presses 4 to bring the pair of friction plates into contact.
is provided at a predetermined position.

The housing 25 has an ear portion 25a formed on one side thereof. The ear portion 25a is provided with a link 39 as a transmission member that is supported by a shaft 38 and rotates, so as to operate the clutch 26. This link 39 has large and small rollers 4 on both ends.
0,41, and the large roller 40 is the safety gate 1.
The small roller 41 is in contact with the recess of the presser metal. Further, the link 39 is biased in one direction by a spring 42, so that the friction clutch 26 is not normally operated.

Next, the operation of the apparatus of this embodiment will be explained.

FIG. 1 shows the safety door 1 in a closed state.
First, when the safety door 1 is opened, the link 39 attached to the housing 25 on the mold clamping cylinder rotates in the direction of arrow A, causing the pusher 35 to slide to the right.

The claw 33b of the L-shaped link 33 sinks into the groove 32a by the pusher 35, and at the same time the pusher plate 37 is pushed leftward by the other claw 33a, causing the pair of friction plates 34, 34 to come into contact with each other, so that the housing 25 and the sleeve 28 are integrated, and the ball screw nut 2
7 is fixed.

At this time, when the mold is being opened and closed by the clamping arm 21 in which the movable plate 2 approaches the fixed plate 8 (in the direction of arrow B), the rotating shaft 24 is moved to the left when viewed from the movable plate side. Although it rotates and moves forward together with the movable plate 2, its movement is locked by the one-way clutch 23, so the movable plate 2 is stopped.

Further, when the movable plate 2 is in a mold opening operation in which it is separated from the fixed plate 8 (in the direction of arrow C), the rotating shaft 24 rotates to the right when viewed from the movable plate side, and moves backward together with the movable plate 2. In this case, the one-way clutch 23 only causes the rotating shaft 24 to idle, so the safety door 1
The mold can be opened without affecting the opening of the mold.

In this embodiment, the clutch is provided on the housing above the mold clamping cylinder, but it may be placed anywhere on the main body of the apparatus as long as the clutch can be operated by opening the safety door. Further, although a friction clutch is used as the clutch here, other dog clutches may be used.

In addition, the transmission member that operates the clutch is
A cam or other mechanical transmission means may be used, or an electromagnetic clutch may be used instead of a mechanical friction clutch, and a transmission member such as a limit switch, a proximity switch, or the like may be driven by an electric signal.

(Effects of the Invention) As is clear from the above description, the present invention operates the clutch fixed to the main body of the device by opening the safety door, fixes the annular body, and operates both clutches by the one-way clutch on the movable plate side. Since the rotating shaft connected therebetween is locked or rotated idly, the movable plate can be immediately stopped during the mold closing operation, and the mold can be opened during the mold opening operation.

Furthermore, since the safety device operates reliably at any position on the movable plate regardless of the thickness of the mold, troublesome work such as adjusting the position of the safety device when replacing the mold can be omitted.

[Brief explanation of drawings]

Fig. 1 is a partial vertical sectional side view showing the operation of the safety device in the injection molding machine of this embodiment, Fig. 2 is an overall side view of the injection molding machine, and Fig. 3 is the operation of the lock plate in the conventional safety device. An explanatory diagram showing,
4 and 5 are a partial side view and a partial plan view illustrating a conventional safety device. 1...Safety gate, 2...Movable plate, 8...Fixed plate, 20...
Mold clamping cylinder, 23...one-way clutch, 24...rotating shaft, 25...housing, 26...friction clutch,
27...Natsuto, 28...Sleeve, 39...Link.

Claims (1)

[Scope of Claims] 1. An injection molding apparatus provided with a safety door that is provided to be movable along the moving direction of the movable plate and can be closed from the side between the movable plate and the fixed plate, comprising: A rotating shaft is attached to the plate via a one-way clutch, and a second clutch is provided between the annular body screwed onto the rotating shaft and the housing fixed to the main body of the device to connect and disconnect the annular body and the housing. Further, the housing is configured to connect the annular body and the housing by connecting a second clutch when the safety door is opened, and to connect the second clutch when the safety door is closed. The injection molding apparatus is provided with a transmission member that disconnects the annular body and the housing when released, and the one-way clutch allows the rotary shaft to freely rotate only during the opening operation of the mold.