JPH078527B2 - Safety equipment for injection molding machines - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical safety device for an injection molding machine which keeps safety by preventing the movable platen from being clamped when the safety door is open.

[0002]

2. Description of the Related Art As a mechanical safety device for an injection molding machine, those shown in FIGS. 5 and 6 are conventionally known. That is, in this safety device, one end of a safety bar 30 having a plurality of sawtooth-shaped fixed teeth 30a formed at predetermined intervals in the axial direction is fixed to the movable platen 3, and the other end of the safety bar 30 is formed on the end plate 4. The stopper 31 that locks the fixed tooth 30a of the safety bar 30 to the end plate 4 and prevents the mold clamping movement of the movable plate 3 through the safety bar 30 is moved up and down with the pin 32 while being inserted through the inserted insertion hole 4a. On the other hand, a rotating rod 34 having a lever 33 is provided on the machine body 1 so as to be vertically rotatable and parallel to the safety bar 30, and when the safety door 5 is open, a stopper 31 is provided. The fixed teeth 30a of the safety bar 30 are locked to prevent the movable platen 3 from being clamped by the toggle type clamping device 6, and the safety door 5
When the door is closed, the roller 36 of the lever 33 is pushed by the cam 35 provided on the safety door 5 and the turning rod 34 is turned, and the roller 37 of the stopper 31 is pushed to stop the stopper 3
1 is removed from the fixed teeth 30a so that the movable platen 3 can be freely clamped and moved (Japanese Utility Model Laid-Open No. 1-115523). Reference numeral 2 is a fixed plate, 7 is a tie rod, and 8 is a mold.

[0003]

However, in the above-mentioned conventional safety device, since one fixed tooth 30a of the safety bar 30 receives the entire mold clamping force of the mold clamping device 6, its shape is made large and strong. There is a need to. Therefore, the safety bar 30 needs to be thick and large, and there is a complaint that the machine becomes large. Further, if the sawtooth-shaped fixed teeth 30a are enlarged, the interval between the fixed teeth 30a is inevitably increased, and accordingly, the stop interval of the movable platen 3 is increased. Further, since the stopper 31 also receives the mold clamping force with one tooth, it is necessary to enlarge its shape, which causes a problem that the opening and closing of the safety door becomes heavy.

The present invention provides a safety device for an injection molding machine, in which the safety bar can be made thin to prevent the machine from becoming large, and the movable platen can be stopped at a small interval, and the production is easy. The purpose is to do.

[0005]

In order to achieve the above object, the present invention provides a mold before a movable platen which is moved by a mold clamping device to clamp a mold with a fixed platen. In an injection molding machine in which a safety door that covers the part is movably provided, a safety bar in which a plurality of fixed teeth are formed at predetermined intervals in the axial direction is provided near the safety door, and the axial direction is the moving direction of the movable platen. And one end is fixed to either one of a fixed member such as a fixed plate and a movable plate, and a plurality of locking teeth are provided on the other fixed member of the safety bar on the other side of the fixed member and the movable plate. A stopper for locking the movable platen to prevent mold clamping movement is pivotally provided on the pivot, and the safety door and stopper are pivoted around the pivot at the final stage of closing movement of the safety door. When the safety door is closed, the locking tooth is retracted from the fixed tooth locking position, and It has a structure obtained by attaching a rotation means for attaching the locking teeth by rotating the stopper to pivot the pivot in locking position of the fixed teeth in the opening movement from the closed state of the door.

[0006]

When the safety door is opened, the rotating means works to rotate the stopper toward the safety bar with the pivot as the fulcrum. As a result, the plurality of locking teeth of the stopper are engaged with the plurality of fixed teeth of the safety bar to prevent the movable platen from being clamped.

In this case, since the plurality of locking teeth are simultaneously locked to the plurality of fixed teeth, even if the shape of each fixed tooth is small, sufficient fixing force can be obtained in the same manner as when the fixed teeth are enlarged. can get. Further, since the fixed teeth can be made small and the interval thereof can be shortened, the movable plate can be stopped at a small interval. When the safety door is closed, the rotating means is operated to rotate the stopper about the pivot so as to separate from the safety bar, and the locking teeth are removed from the fixed teeth to allow the movable platen to move freely.

[0008]

1 to 4 show an embodiment of the present invention.
The basic structure of the injection molding machine is well known and is the same as the injection molding machine of FIG. That is, the fixed platen 2 is fixed to the machine body 1 (FIG. 5). An end plate 4 is attached to the fixed platen 2 via a tie rod 7. A movable platen 3 is arranged between the fixed platen 2 and the end plate 4,
It is slidably supported by the tie rod 7. The movable platen 3 is moved toward the fixed platen 2 by the mold clamping device 6 to clamp the molds 8 and 8 with the fixed platen 2. In front of the fixed platen 2 and the movable platen 3, a safety door 5 is provided so as to be openable and closable to the left and right in order to avoid danger during mold clamping operation.

In the present invention, the safety bar 10 is attached to the movable platen 3 of the injection molding machine having the above-mentioned structure with one end fixed by the bolt 11. On the upper surface of the safety bar 10, a plurality of mountain-shaped fixed teeth 10a are formed at predetermined intervals in the axial direction. The safety bar 10 is arranged on the back side of the safety door 5 and has a free end protruding in front of the fixed platen 2 so that its axial direction coincides with the moving direction of the movable platen 3.

A stopper 12 is attached to the fixed platen 2.
The pivot shaft 13 fixed to the above is inserted into the elongated hole 12b, and is pivotally attached so as to be vertically rotatable in a vertical plane along the axial direction of the safety bar 10 and movable in the longitudinal direction. On the lower surface of the stopper 12, a plurality of mountain-shaped locking teeth 12a having the same shape as the fixed teeth 10a of the safety bar 10 are formed. The pivot 13 is provided so as to project above the fixed tooth 10a of the safety bar 10.

Here, the shapes of the fixed teeth 10a and the locking teeth 12a (the angle of inclination of the tooth surface), and the pivot 13 with respect to the fixed teeth 10a.
The positional relationship between the fixed tooth 10a and the locking tooth 12a is such that the stopper 12 does not rotate upward about the pivot 13 as a fulcrum with respect to the right movement of the safety bar 10 in FIG. The engagement state of the stop teeth 12a is maintained, and when the safety bar 10 is moved to the left, the stopper 12 rotates upward about the pivot 13 as shown in FIG.
It is set so that the locking tooth 12a is disengaged from a.

Therefore, the fixed tooth 10a is engaged with the locking tooth 12a.
In the state shown in FIG.
Is moved to the right by almost the play of the long hole 12b, the mold clamping movement of the movable platen 3 is blocked, and when the safety bar 10 is moved to the left, the stopper 12 is rotated upward so that the movable platen 3 is opened. Be free.

The fixed platen 2 is provided with an abutting protrusion 2a. The contact projection 2a contacts the end surface 12c of the stopper 12 to stop the right movement of the stopper 12, and receives the mold clamping force of the mold clamping device. According to this structure, since a strong mold clamping force does not act on the pivot 13, it is not necessary to use the thick and strong pivot 13.

The contact projection 2a and the end surface 12c of the stopper 12
And the stopper end surface 12c are brought into contact with the contact projection 2a, the stopper 12 and
Is prevented from rotating upward. At the beginning of the movement of the safety bar 10 to the left in FIG. 3, the stopper 12 moves to the left together with the safety bar 10 by substantially the amount of play of the elongated hole 12b, and the end face 1 is moved.
Since 2c is separated from the contact projection 2a, the stopper 12 can freely rotate upward. The shapes of the contact projection 2a and the end surface 12c are arbitrary, and for example, the end surface 12c can be formed in an arc shape and the stopper 12 can be freely rotated upward while contacting the contact projection 2a.

On the front surface of the stopper 12, a roller 14 is attached to the shaft 1.
6 is attached, and a cam 15 is attached to the safety door 5. The cam 15 is inclined so as to be higher as it comes closer to the movable platen 3 from the fixed platen 2, and is arranged at a position crossing a vertically rotating surface of the roller 14 around the pivot shaft 13.

When the safety door 5 is moved to the movable platen 3 side and opened, the cam 15 separates from the roller 14 and rotates the stopper 12 downward as shown in FIG. Also, the cam 15
At the final stage of the closing movement of the safety door 5, the roller 14 is touched and pushed, and the stopper 12 is gradually rotated upward and retracted from the locking position. The roller 14 and the cam 15 constitute a rotating means 17 for the stopper 12.

Next, the operation of the safety device of the injection molding machine according to the present invention constructed as described above will be described. 1 and 3 show a state in which the safety door 5 is opened. The stopper 12 falls down by its own weight and each locking tooth 12a is attached to the safety bar 10.
Mesh with the fixed tooth 10a. When the safety bar 10 moves to the right in FIG. 3 due to the mold clamping movement of the movable platen 3, the stopper 12 moves a little to the right, bringing the end face 12c into contact with the contact protrusion 2a and stopping. The mold clamping movement of the movable platen 3 thus stopped stops, and there is no danger. The stopper 12 slightly moves toward the movable platen 3 when the movable platen 3 moves to open the mold, separates the end face 12c from the contact protrusion 2a, and then rotates upward to move the locking teeth 12a to the fixed teeth of the safety bar 10. Remove from 10a.

Further, when the safety door 5 in the opened state is closed, the stopper 12 is rotated upward by the action of the cam 15 via the roller 14 so that each locking tooth 12a is fixed to the fixed tooth 10a of the safety bar 10.
Remove from Therefore, the movable platen 3 can be freely moved in the mold clamping operation.

In the illustrated embodiment, the safety bar 10 is attached to the movable platen 3.
In addition, the stopper 12 is provided on the fixed plate 2 respectively,
It is also possible to attach the safety bar 10 to the fixed platen 2 and provide the stopper 12 on the movable platen 3. Also, one of the safety bar 10 and the stopper 12 is used as the movable platen 3, and the other is used as the end plate 4.
It can also be implemented by being provided in the.

The cam 15 serves as the stopper 12, and the roller 1
It is also possible to provide each of the safety doors 4 with 4. Further, the stopper 12 may be pivotally attached by the pivot 13 instead of by the elongated hole 12b.

[0021]

As described above, the safety device of the injection molding machine according to the present invention is provided with a metal plate before the movable platen which is moved by the mold clamping device and clamps the mold with the fixed platen. In an injection molding machine in which a safety door that covers the mold part is movably provided, a safety bar that has a plurality of fixed teeth formed at predetermined intervals in the axial direction moves the movable plate in the axial direction near the safety door. It is provided with one end fixed to either one of the fixed member such as a fixed plate and the movable plate, and the plural locking teeth are fixed to the other of the fixed member and the movable plate. A stopper that locks to the teeth to prevent the mold clamping movement of the movable plate is rotatably provided on the pivot, and the above-mentioned safety door and stopper use the stopper as a fulcrum at the final stage of the closing movement of the safety door. Pivot to retract the locking tooth from the locking position of the fixed tooth when the safety door is closed. In addition, since the safety door is opened from the closed state, the stopper is rotated about the pivot as a fulcrum so that the locking teeth are positioned at the locking positions of the fixed teeth. With the plurality of locking teeth and fixed teeth having a small interval, it is possible to properly prevent the mold clamping movement of the movable plate.

Therefore, the safety bar can be made thin to prevent the machine from becoming large, and the movable plate can be stopped at a small interval. Moreover, since the stopper can be made smaller, opening and closing of the safety door is lighter, and the structure is simple overall, and commercially available racks can be used for the safety bar and the stopper, which facilitates manufacture.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a safety device for an injection molding machine according to the present invention.

FIG. 2 is a II-II arrow view of FIG. 1, showing a relationship between a safety bar, a stopper, a cam, and the like.

FIG. 3 is a front view showing a meshing state of locking teeth of a stopper with respect to fixed teeth of a safety bar.

FIG. 4 is a front view showing a state in which the stopper is rotated upward by the mold opening movement of the safety bar.

FIG. 5 is a front view of a conventional safety device with a part cut away.

6 is a cross-sectional view showing a relationship between a safety bar and a stopper and the like of the safety device of FIG.

[Explanation of symbols]

 2 Fixed plate (fixed member) 3 Movable plate 5 Safety door 6 Mold clamping device 8 Mold 10 Safety bar 10a Fixed tooth 12 Stopper 12a Locking tooth 13 Axis 14 Roller 15 Cam 16 Rotation means

Claims (1)

[Claims] 1. An injection molding machine in which a safety door for covering a mold part is movably provided in front of a movable platen which is moved by a mold clamping device and clamps a mold with a fixed platen. , A safety bar that has a plurality of fixed teeth formed at predetermined intervals in the axial direction,
It is provided near the safety door with its axial direction aligned with the moving direction of the movable platen and with one end fixed to one of the fixed platen fixed member and the movable platen. , A stopper that locks a plurality of locking teeth with a plurality of fixed teeth of the safety bar to prevent the mold clamping movement of the movable plate is pivotally provided on the pivot, and the safety door and the stopper are
At the final stage of the closing movement of the safety door, the stopper is rotated around the pivot as a fulcrum to retract the locking tooth from the locking position of the fixed tooth in the closed state of the safety door, and to open the safety door from the closed state. A safety device for an injection molding machine, wherein a rotation means for rotating the stopper about a pivot as a fulcrum to attach the locking tooth to the locking position of the fixed tooth is additionally provided.