JPH0438505B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mechanical safety device in a mold clamping device that can be applied to an injection molding machine.

(Prior art) Mold clamping devices such as injection molding machines are equipped with safety devices to prevent workers from getting caught in the mold during operation, and generally there is a safety device on the operating side of the mold clamping device. A safety door is provided and hydraulically and electrically interlocked so that the mold clamping operation will not occur unless the safety door is closed. However, even though these devices and safety gates are open, there is always a danger of the movable plate moving forward due to a failure in the hydraulic or electrical system, and safety must be ensured even in the unlikely event of a malfunction. Mechanical safety devices are also installed.

An example of a conventional mechanical safety device of this kind will be explained with reference to FIGS. A stopper block 6 having a hole 7 through which the safety rod 5 passes is attached to the plate 1, and a shutter 8 for closing the hole 7 is provided on the end surface of the stopper block 6 on the movable plate 2 side. Cam 1 attached to safety door 9
0, and when the safety door 9 is open, the hole 7 is closed and the mold closing operation (advance) of the movable plate 2 is disabled. In addition, when the safety door 9 is closed, the shutter 8 is moved to the hole 7 by the cam 10.
(state shown by the two-dot chain line in Fig. 10), and move the movable plate 2.
Enables mold closing operation. FIG. 11 shows a state in which the mold closing operation is completed.

When injection and cooling are completed, the movable plate 2 enters mold operation (retraction). At this time, the stability door 9 may be opened after the mold closing operation is completed, or may be opened immediately after the mold opening operation. When the safety door 9 is opened during the mold opening operation, the shutter 8, which was distant from the safety rod 5, comes to engage with the safety rod 5 due to the cam 10 attached to the safety door 9. The shutter 8 moves up and down following the convex portion 5a and the concave portion 5b provided in the shutter 5. Also 3
indicates the flange or toggle plate of the clamping cylinder.

However, in the conventional device, the movable plate 2
When the safety door 9 is opened during the mold opening operation, the shutter 8 moves up and down following the convex portion 5a and concave portion 5b of the safety rod 5; When climbing, the movement speed v of safety rod 5 is 40
m/sec to 50 m/sec, the shutter 8 will be subject to a large force F in the same direction as the movement direction of the safety rod 5 and will try to bend, so the plate should be thick and rigid to withstand this force. It had to be done (Figure 12).

Also, in order to reduce the force F that bends the shutter 8, if the angle of inclination of the convex portion 5a is made shallow, the safety rod 5
If the pitch of the protrusion 5a provided on the safety rod 5 increases and the movable plate 2 closes the mold due to a malfunction while the safety door 9 is open, the vertical surface of the protrusion 5a provided on the safety rod 5 will hit the shutter 8. There was a runner-up in which the amount of movement toward the mold clamping side was large, and its role as a safety device was weakened.

Furthermore, as mentioned above, the shutter 8 must be made rigid, so when the shutter 8 falls from the convex part 5a of the safety rod 5 to the concave part 5b, an impact sound is generated (continuous metallic sound), which may cause problems in the working environment. I feel much better. Furthermore, since the shutter 8 is operated by a cam 10 attached to the safety door 9, the operating force for the safety door 9 becomes large when the safety door 9 is closed and opened.

(Problems to be Solved by the Invention) The present invention attempts to solve the conventional problems such as increasing the thickness of the plate, weakening its role as a safety device, and generating impact noise. .

(Means for solving the problem) For this reason, the present invention has one end fixed to a movable plate,
a safety rod having a plurality of recesses whose other end is guided by a fixing member such as a fixing plate; and a safety rod provided on the fixing member,
A safety device for a mold clamping device comprising a shutter mechanism that removably engages a shutter in a concave portion of the safety rod to prevent movement of the safety rod in the mold closing direction, the safety device being attached to the fixing plate, a stopper block having a hole through which the stabilizing rod can move, and a guide slidably supported by the stopper block and normally biased so that one end protrudes to a position supporting the lower surface of the shutter. The center part is pivotally connected to the pin and the other end of the guide pin, and one end is equipped with a roller that can engage with the recess of the safety rod, and the other end is equipped with an arm, and the arm is connected to the cam on the safety door side. It has a structure consisting of a key-shaped lever that, when engaged, raises the roller and swings so that the roller does not engage with the recess of the safety rod, and this is used as a means to solve the problem. It is.

(Function) In normal operation, when the safety door is closed, the lever arm is pushed by the cam attached to the safety door.
The roller is lifted with the pin as the center of swing. At this time, the engagement between the roller and the safety rod is broken, and the movable plate can perform mold closing and mold opening operations without any problem. Next, in the event of an abnormality, the safety door is not closed, so the roller remains on the safety rod, and when the movable plate closes the mold, it hooks the roller, the guide pin moves to the right, and the shutter is placed on the safety rod. It falls upward, and the vertical surface of the safety rod hits the shutter, making it impossible for the movable plate to move to the right (mold closing operation).

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. Figs. 1 to 7 show an embodiment of the present invention, in which 1 is a fixed plate, 2 is a movable plate, and 3 is a mold clamping cylinder. Flange or toggle plate, 4 is tie bar, 5
8 is a safety rod, 8 is a shutter, 9 is a safety door, and 10 is a cam, which are the same as the conventional device.

Next, I will explain the points that differ from the conventional ones.
Reference numeral 21 denotes a stopper block, which is attached to the fixed plate 1 and has a hole 21a through which the safety rod 5 passes, and holes 21b (two on each side, four in total) through which the guide pin 22 slides. 22 is a guide pin,
It is inserted into the hole 21b of the stopper block 21,
One end serves as a stopper for the shutter 8 to prevent the shutter 8 from touching the safety rod 5, and the other end is attached to a lever 26 via a pin 25. 2
Reference numeral 3 denotes a stopper, which is integrally assembled with the guide pin 22, and prevents the stopper of the spring 24 and the guide pin 22 from moving to the left more than shown (in FIGS. 1 and 2) due to the force of the spring 24. As such, this part of the stopper block 21 serves as a stopper.

One end of the spring 24 is connected to the stopper block 2.
1, and the other end hits the stopper 23, and the guide pin 22 is always pressed to the left via the stopper 23. 25 is a pin, guide pin 22
and the lever 26, and the lever 2
It is also the pivot axis of 6. Lever 26 is roller 27
and the guide pin 22, and also serves as a swinging arm of the roller 27. An arm 26a protrudes from the lever 26 on the safety door 9 side. The roller 27 is supported at both ends by levers 26, and is allowed to rotate freely at the support portion. Moreover, the central part is covered with rubber or resin material to minimize the sound when it falls onto the safety rod 5.

The stopper block 21 is attached to the fixed plate 1, and the safety rod 5 is attached to the same stopper block 21.
The shutter 8 passes through the hole 21a provided in the
It protrudes on the opposite side where it is attached. The shutter 8 is prevented from falling by the guide pin 22, and in this state the safety rod 5 can move in the axial direction without being hindered by the shutter 8. However, the convex portion 5a
The vertical plane of is obstructed by rollers 27. Further, the guide pin 22 is always pressed to the left by a spring 24 via a stopper 23. At this time, the shutter 8 is riding on one end of the guide pin 22. On the other hand, the roller 27 is engaged with the guide pin 22 via the lever 26 and the pin 25, and rides on the safety rod 5. At this time, roller 27, pin 2
5. The centers of the guide pins 22 are on the same line.

Next, the operation of the embodiment configured as above will be explained. First, during normal operation (after closing the safety door, mold closing operation, and opening the safety door after the mold closing operation is completed), when the safety door 9 is closed, the cam 1 attached to the safety door 9
0 pushes the arm 26a of the lever 26, and the pin 2
The roller 27 is lifted up with the swing center at 5 (the state indicated by the two-dot chain line in FIG. 2). At this time, the engagement between the roller 27 and the safety rod 5 is broken, and the safety rod 5 is movable in the axial direction, so that the movable plate 2 can perform mold closing and mold opening operations without any problem.

Next, in another normal state (when the safety door is opened after the safety door is closed and during the mold closing operation and the mold opening operation), the mold closing operation of the movable plate 2 is performed without any problem as described above. When the movable plate 2 opens the safety door 9 during the mold opening operation,
The roller 27, which had been pushed up by the cam 10 attached to the safety door 9, falls onto the safety rod 5 due to its own weight, but the roller 27 rotates slightly at the support of the lever 26 and still oscillates around the pin 25. Since the roller 27 moves dynamically, the protrusion 5a of the safety rod 5
The guide pin 22, which is engaged with the roller 27, remains pressed to the left by the spring 24 by simply repeating the movement of climbing up the slope of 22 and will not fall. Furthermore, since the intermediate portion of the roller 27 is covered with rubber or resin, even if it falls onto the safety rod 5, almost no impact is generated.

Next, referring to FIG. 5, we will explain the case of an abnormality (when the safety door is opened and the mold closing operation occurs). In this case, the safety door 9 is not closed, so the roller 27 rides on the safety rod 5. It stays on. Movable plate 2
When the mold closes, the safety rod 5 similarly moves to the right. By moving in this way, the safety rod 5
The vertical surface of the convex portion 5a hooks the roller 27. Therefore, as the roller 27 is pulled to the right, the spring 24 is bent and the guide pin 22 is also moved to the right. Therefore, the shutter 8, which had been prevented from falling by the guide pin 22, falls onto the safety rod 5, and the shutter 8 falls onto the safety rod 5, and the shutter 8 falls onto the through hole 21 of the stopper block 21.
a is semi-occluded, the vertical surface of the convex portion 5a of the safety rod 5 hits the shutter 8, making it impossible for the movable plate 2 to move to the right (mold closing operation).

FIG. 6 shows another embodiment of the present invention, in which a stopper block 21 is attached to a mold clamping cylinder or toggle plate 3, and its function is similar to that described above.

FIG. 7 shows a safety rod 50 corresponding to the safety rod 5 of the present invention, with unevenness 50a, 50b on the entire circumference in the radial direction.
Although the safety rod 5 is provided with a groove, its function is the same as that of the safety rod 5. In addition, by employing a guillotine type shutter 38 in place of the shutter 8 (FIG. 4) and engaging the guide pin 22 with the notch 38a, the same operation and effect as described above can be obtained.

(Effects of the Invention) Since the present invention is configured as described in detail above, the shutter does not operate every time the safety door is opened or closed. In addition, even if the safety door opens while the movable plate is opening the mold, the shutter does not operate and only the roller moves up and down, so the shutter only has to withstand the compressive force from the safety rod, making it lighter. Since the shutter is not pushed up or down by the cam attached to the safety gate, no large operating force is required when the safety gate is closed. Furthermore, when opening the safety door, the force of the lever arm acts in the direction of opening the safety door, so less operating force is required. Since the middle part of the roller is made of rubber or resin, there is little impact noise when the roller falls onto the safety rod.

[Brief explanation of drawings]

Fig. 1 is a plan view of a mechanical safety device of a mold clamping device showing an embodiment of the present invention, Fig. 2 is a sectional view from C to C in Fig. 1, and Fig. 3 is a sectional view from D to D in Fig. 2. , FIG. 4 is a side view of an embodiment different from FIG. 3, FIG. 5 is a front view with a different operating state from FIG. 2, FIG. 6 is a front view of an embodiment different from FIG. 2, and FIG. 8 is a plan view of a conventional mechanical safety device, FIG. 9 is a sectional view taken from A to A in FIG. 8, and FIG. 10 is a plan view of another embodiment of the safety rod. B-B sectional view, Fig. 11 is No. 9
A-A sectional view of FIG. 8 showing a different operating state from the figure;
FIG. 12 is an enlarged view of the main part of FIG. 11. Explanation of the main parts of the diagram, 1... Fixed plate, 2... Movable plate, 5... Safety rod, 8... Shutter, 9...
Safety door, 10... cam, 21... stopper block, 22... guide pin, 23... stopper, 26... lever, 27... roller.

Claims (1)

[Claims] 1. A safety rod having a plurality of recesses with one end fixed to a movable plate and the other end guided by a fixed member such as a fixed plate, and a safety rod provided on the fixed member so that a shutter can be engaged and detached from the recess of the safety rod. A safety device for a mold clamping device comprising a shutter mechanism that engages with the safety rod to prevent movement of the safety rod in the mold closing direction, the safety device having a hole that is attached to the fixing plate and through which the safety rod can move. A stopper block, a guide pin slidably supported by the stopper block and normally biased so that one end thereof projects to a position supporting the lower surface of the shutter; A roller that can be engaged with the recess of the safety rod is mounted on one end, and an arm is provided on the other end, and when the arm engages with the cam on the safety door side, the roller is raised and the roller is A mechanical safety device for a mold clamping device, characterized by comprising a key-like lever that swings so as not to engage with a recess of a safety rod.