JPH045303Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a safety device for an injection molding machine that automatically opens and closes a safety door safely.

(Prior Art) Generally, an injection molding machine is equipped with a safety door 1 as shown in FIG. 5 in order to prevent unexpected accidents from occurring during mold clamping. This safety door 1 has a movable panel 2
It is installed on the side of the movable platen 2 and can run freely along a rail (not shown) extending in the direction of movement of the movable platen 2.

The safety door 1 is closed prior to mold clamping to block the space between the fixed platen 3 and the movable platen 2 from the outside.

By the way, when closing this safety door 1, if there is an obstacle in the travel path of the safety door 1, the safety door 1 may collide with it and the safety door 1 may be damaged or the drive mechanism of the safety door 1 may be damaged. It may cause a malfunction.

Therefore, a means for detecting an obstacle is provided at the front end of the safety door 1, and when an obstacle is detected, the movement of the safety door 1 is stopped.

FIG. 6 shows a conventional safety device of this kind, in which one end of the curtain 4 is fixed to the front end of the safety door 1, and a chain 5 is inserted through the other end. One end is attached to the fixing pin 6, and the other end is attached to one end of the lever 7.

The center part of the lever 7 is rotatably connected to a bracket 8 fixed to the safety door 1 via a pin 8a, and the other end of the lever 7 is connected to a limit switch 9.
is in contact with. That is, limit switch 9
is fixed to the safety door 1, and the other end of the lever 7 is connected to a limit switch 9 by a spring 10.
is in constant contact with the

Next, the operation of the above conventional device will be described.
As mentioned above, the safety door 1 is closed prior to mold clamping, but if an obstacle exists when traveling in the closing direction, the chain 5 in a tensioned state hits the obstacle and bends, and the lever 7 is bent. spring 10
The other end of the lever 7 moves away from the limit switch 9, and the limit switch 9 operates to output a signal. This output signal is supplied to the drive mechanism of the safety door 1 (not shown), and the safety door 1 stops running.

(Problem to be solved by the invention) As mentioned above, in the conventional example, since the chain 5 is always in a tensioned state, the slight vibration of the chain 5 causes the lever 7 to rotate counterclockwise, causing the limit switch 9 to rotate. Therefore, the limit switch 9 is likely to operate erroneously even when there is no obstacle.

When the obstacle is removed, the chain 5 returns to its original position and the lever 7 is brought into contact with the limit switch 9 by the spring force of the spring 10. Limit switch 9 is easily damaged.

Furthermore, the number of parts is large and the configuration is complicated.

The present invention was devised to solve the above-mentioned problems, and aims to provide a safety device for an injection molding machine with a simple structure that hardly causes malfunctions and is durable.

(Means for Solving the Problems) The present invention has a detecting member movably attached to the front end of the safety door, and a spring member that resists movement of the detecting member provided between the detecting member and the safety door. Furthermore, a detector is provided which is activated by the elastic deformation of the spring member and generates a signal to stop the safety door from moving.

(Function) When the safety gate is moved to close the side of the space formed by the fixed platen and the movable platen prior to mold clamping, if there is an obstacle in the direction of movement of the safety door, the safety door will close. When the detection member hits an obstacle, the detection member elastically deforms the spring member and is displaced backward in the traveling direction of the safety door, and the spring member operates the detector by elastic deformation. The detector thereby generates a signal that causes the safety gate to stop running.

If there is no obstacle, the detection member vibrates for some reason and is displaced backward in the traveling direction of the safety door, causing the spring member to elastically deform, but this elastic deformation is too small to operate the detector.

(Example) Examples of the present invention will be described below with reference to the drawings. In FIG. 1, the same reference numerals as in FIG. 5 indicate the same or corresponding parts.

FIG. 1 shows the closed state of the safety door 1, and a detection member 11 is movably attached to the front end of the safety door 1 in the traveling direction, as also shown in FIG. The detection member 11 has a U-shaped cross section as shown in FIG. 3, and its open end slidably holds the front end of the safety door 1. A long hole 12 extending in the running direction of the safety door 1 is formed in this open end,
Both ends of a pin 13 passing through the safety door 1 are slidably inserted into the elongated hole 12.

One end of an upper spring member 14 made of a leaf spring is fixed to the inner surface of the front end of the detection member 11 . This upper spring member 14 extends downward, and the other end is in elastic contact with the front end surface of the safety door 1.

Another such spring member is provided. The other spring member is a lower spring member 15 located below the upper spring member 14, one end of which is fixed to the inner surface of the front end surface of the detection member 11, and the other end extends upward and is attached to the safety door 1. It is in elastic contact with the front end surface.

A macro switch 16 is fixed to the front end of the safety door 1, an operating lever 16a of which is located on the front end surface of the safety door 1, and its tip is in elastic contact with the upper spring member 14.

Note that rubber plates 17 are attached to the upper and lower parts of the inner surface of the front end surface of the detection member 11, and are used to reduce the impact of the detection member 11 on the safety door 1.

Returning to FIG. 1, 18 is a cylinder that uses air or oil as a working fluid, and its piston rod 18
The tip of a is attached to a bracket 19 fixed to the front of the safety door 1, as shown in FIG. The bracket 19 is fixed to the upper part of the safety door 1, and its lower end is located inside the safety door 1, and the piston rod 18a is attached to this lower end.

In addition, in FIG. 4, 20 is a cover provided on the side of the fixed platen 3, 21 is a support member that supports the cover 20 from above, and 22 is a stopper attached to the support member 23 that supports the cover 20 from below. In the closed state, the lower part of the front end surface of the safety door 1 comes into contact with the stopper 22.

Next, the operation of the device having the above configuration will be described.

As described above, before the movable platen 2 is brought close to the fixed platen 3 and the mold is clamped, the sides of the space between the movable platen 2 and the fixed platen 3 are closed by the safety gate 1. For this purpose, the cylinder 18 is actuated and the piston rod 18
a is extended to move the safety door 1 in the direction of the fixed platen 3.

When the safety door 1 is running, if there is an obstacle in front of it in the running direction, the detection member 11 will collide with the obstacle. As mentioned above, the detection member 11 has the elongated hole 21 and the pin 13.
Since the safety door 1 is movable, when it collides with an obstacle, the upper and lower spring members 14 and 15 are elastically deformed and the safety door 1 is displaced rearward in the running direction. Then, the detection member 11 is displaced to some extent and the upper spring member 1
4 approaches the front end surface of the safety door 1, the actuating lever 16a bends more and the micro switch 16
is activated to generate a signal that stops cylinder 18 from operating. This causes the safety door 1 to stop running.

The above description is for the case where there is an obstacle, but even when there is no obstacle, the detection member 1
1 may be displaced. There are various causes for this, but for example, when the base of an injection molding machine vibrates,
Alternatively, this may occur when the safety door 1 is lightly touched by a hand, but in these cases, even if the detection member 11 is displaced backward and the upper and lower spring members 14 and 15 are elastically deformed, this elastic deformation is small and the micro switch 16 is I haven't gotten to the point where it works. In other words, malfunctions of the microswitch 16 are suppressed as much as possible.

If there is no obstacle, the safety door 1 comes into contact with the stopper 22 and stops traveling, closing the space between the movable platen 2 and the fixed platen 3.

(Effects of the invention) As explained above, in the present invention, the detector is operated by the elastic deformation of the spring member provided between the detection member and the safety door, so there is a situation where the safety door stops running due to malfunction. will be prevented as much as possible.

Furthermore, since the detector is operated by elastic deformation of the spring member, damage is prevented.

Furthermore, the number of parts is small and the configuration can be simplified.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the safety device of the injection molding machine according to the present invention, Fig. 2 is an enlarged view showing the main parts of the invention, Fig. 3 is a plan view of the detection member, and Fig. 4 is the same as Fig. 1. FIG. 5 is an overall view of the injection molding machine, and FIG. 6 is a schematic diagram of a conventional injection molding machine. 1...Safety gate, 2...Movable plate, 3...Fixed plate,
11...Detection member, 14, 15...Spring member, 1
6...Micro switch (detector).

Claims (1)

[Claim for Utility Model Registration] Injection molding comprising a movable plate that can move toward and away from a fixed plate and has a safety door that can move freely in the direction of movement and that can close the side of the space between the fixed plate and the movable plate. In the machine safety device, a detection member is movably attached to the front end of the safety door, a spring member is provided between the detection member and the safety door to resist movement of the detection member, and the elasticity of the spring member is further provided. A safety device for an injection molding machine, characterized in that it is provided with a detector that is activated by deformation and generates a signal to stop the travel of a safety door.