JPH0224529Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field The present invention relates to a toggle type mold clamping device with a tie bar extraction device.

(B) Prior Art There are two types of mold clamping devices: a direct pressure type mold clamping device that directly clamps a mold using a large-diameter hydraulic cylinder, and a toggle type mold clamping device that uses a toggle link mechanism. Some direct pressure type mold clamping devices allow larger molds to be attached and removed by pulling out one or two of the four tie bars when attaching or removing a die. In other words, if the tie bars cannot be removed, only molds with external dimensions that can pass through the gap between the tie bars can be installed, but by making the tie bars removable, it is possible to install molds with larger external dimensions. It becomes possible. 1 to 3 show a conventional toggle type mold clamping device that is not provided with a tie bar extraction device. Fixed platen 12 and end housing 14
are connected by four tie bars 16. A movable platen 18 supported movably in the axial direction with respect to the tie bar 16 is connected via a toggle mechanism 26 to a crosshead 24 at the tip of a rod 22 of a mold clamping cylinder 20 attached to the end housing 14. The toggle mechanism 26 includes a link 28,
30 and 32, these links are connected to each other by pins 34 and are connected to the crosshead 24 and end housing 14, respectively.
and is connected to the movable platen 18 by pins 36, 38 and 40. A fixed die 42 is attached to the fixed platen 12, and a movable die 44 is attached to the movable platen 18. The end housing 14 is movably provided on the frame 46, and its fixing position relative to the tie bar 16 can be adjusted by a mold thickness adjusting device 48, which is shown enlarged in FIG. The mold thickness adjustment device 48 includes a screw 50 formed at the end of the tie bar 16 and an adjustment nut 5 that engages with this screw 50.
2, a nut cover 54 that restrains the adjustment nut 52 in the axial direction with respect to the end housing 14, and a sprocket 5 provided on the outer periphery of the adjustment nut 52.
6 and four sprockets 5 as shown in Figure 2.
6, and a drive motor 6 that drives a sprocket 60 that meshes with the chain 58.
It is composed of 2.

During mold clamping, the mold clamping cylinder 20 is operated to push out the rod 22, and this force is amplified by the toggle mechanism 26 and transmitted to the movable platen 18 to press the movable mold 44 against the fixed mold 42. In order to most efficiently double the force of the mold clamping cylinder 20 by the toggle mechanism 26, the toggle mechanism 26 must be activated in the mold clamped state.
It is necessary for the links 30 and 32 to be in a state just before they become in a straight line. Since the thickness of the fixed mold 42 and the movable mold 44 differ depending on the type of mold, it is necessary to adjust the distance between the fixed platen 12 and the movable platen 18 when the toggle mechanism 26 is in the most extended state. Become. This adjustment is performed by the mold thickness adjustment mechanism 48.
It is carried out by. That is, the motor 62 is driven to rotate each adjustment nut 52 via the chain 58, thereby moving the end housing 14 in the axial direction. Each adjusting nut 52 that engages with the screws 50 of the four tie bars 16 is driven through one chain 58, so that each adjusting nut 52 all rotates in synchronization. For this reason, each tie bar 16
The relative positions of the adjustment nuts 52 with respect to the four tie bars 16 and the four adjustment nuts 52 are the same, respectively. Therefore, the parallelism of the end housing 14 with respect to the fixed platen 12 is reliably maintained even after the end housing 14 is moved in the axial direction.

The toggle type mold clamping device described above is not equipped with a tie bar extraction device, so in order to be able to attach a mold with large external dimensions, the spacing between the tie bars must be increased, and the mold clamping device Everything was becoming larger and more expensive. In addition, very careful work is required to avoid damaging the mold by contacting the tie bar when replacing the mold.
The work time for changing molds was becoming extremely long.

Note that Japanese Patent Publication No. 52-30370 discloses a toggle type mold clamping device equipped with a tie bar extracting device. That is, a structure is shown in which the tie bar to be pulled out is connected to a nut, and the tie bar is pulled out from the fixed platen side while rotating both together. However, in the case of this tie bar extraction device, since the tie bar is pulled out while rotating, spiral scratches may be formed on the tie bar surface, which may impede the guiding operation.Also, the mold thickness can be adjusted to rotate the tie bar. It is necessary to increase the driving force of the device. In addition, when resetting a pulled out tie bar, the pulled out tie bar will be under a compressive load, and the other tie bars will be under a tensile load, which will cause the tie bars to stretch unevenly during mold clamping, causing the mold to close. There is a problem that the force is not constant. This is because when resetting the tie bars, the tie bars that have been pulled out engage the nuts on the fixed platen side and are stopped, so they receive a compressive load, and the other tie bars receive a tensile load to move the movable platen. becomes. For this reason, buckling and play in the movable parts occur in opposite directions between the pulled out tie bars and the other tie bars, resulting in uneven extension of the tie bars when the mold is clamped.

Further, Japanese Utility Model Publication No. 57-1015 discloses a system in which the two upper tie bars are simultaneously pulled out using a pull-out cylinder. However, in this case, a mold thickness adjustment mechanism is not provided and the mold thickness cannot be adjusted.

In addition, in Utility Model Application Publication No. 55-55255, motor,
A system in which the tie bar is pulled out using a pinion and rack is shown. However, in this case, since a mechanism for synchronizing the tie bars is not provided, it is difficult to synchronize the mold clamping force generated when resetting a pulled out tie bar with other tie bars.

(c) Purpose of the invention The present invention enables the tie bars of a toggle type mold clamping device to be pulled out with simple operation and structure, and enables the installation of a mold with larger external dimensions than conventional ones for the same tie bar spacing. The purpose of this invention is to facilitate the mold replacement work and to solve the conventional problems mentioned above at the same time.

(d) Structure of the invention The present invention achieves the above object by making it possible to connect an adjusting nut to a rotary cylinder rotated by a drive mechanism so as to rotate integrally therewith. That is, according to the present invention, a predetermined number of tie bars are connected to the fixed platen by a tie bar fixing mechanism that can fix or release the tie bars from the fixed platen. A mold thickness adjustment mechanism is provided on the tie bar that is not provided, and the mold thickness adjustment mechanism includes a first adjustment nut that engages with a screw provided on the outer periphery of the tie bar, and a first adjustment nut that is axially aligned with respect to the end housing. The tie bar with the tie bar fixing mechanism is equipped with a mold thickness adjustment/extraction mechanism, and the mold thickness adjustment/extraction mechanism engages with a screw provided on the outer periphery of the tie bar. a second adjustment nut; a rotary barrel capable of switching between a state in which it rotates together with the second adjustment nut and a state in which it can rotate independently of each other according to the relative axial position of the second adjustment nut; a cover that restricts movement of the second adjustment nut; a locking plate that is movable between a position that restricts movement of the second adjustment nut in the axial direction and a position that releases it;
It has a pull-out drive mechanism that moves the tie bar in the axial direction, and a rotation drive mechanism that rotationally drives the rotary cylinder and the first adjustment nut in a synchronized state.

(e) Examples Examples of the present invention will be described below with reference to Nos. 4 to 10 of the attached drawings.
This will be explained based on the diagram.

Fixed platen 112 and end housing 114 are connected by tie bars 116. A movable platen 118 supported movably in the axial direction with respect to the tie bar 116 is connected to the rod 12 of a hydraulic mold clamping cylinder 120 attached to the end housing 114.
2-tip crosshead 124 and toggle mechanism 126
are connected via. Toggle mechanism 126 is comprised of links 128, 130 and 132 connected to each other by pins 134 and connected to crossheads 124 and 132, respectively.
It is connected to the end housing 114 and movable platen 118 by pins 136, 138 and 140. A fixed die 142 is attached to the fixed platen 112, and a movable die 144 is attached to the movable platen 118. End housing 114 is frame 1
46 so as to be movable. Among the four tie bars 116, three of them except the one on the upper right in FIG.
48 are provided. The mold thickness adjustment mechanism 148 is
an adjustment nut 152 (first adjustment nut) that engages with a screw 150 formed at the end of the tie bar 116;
It has a nut cover 154 that restrains the adjusting nut 152 in the axial direction with respect to the end housing 114, and a sprocket 156 provided on the outer periphery of the adjusting nut 152, and a chain 158 is connected to the sprocket 156. chain 15
8 is a motor 1 that rotationally drives the sprocket 160.
62. Remaining tie bar 116
(the upper right one in FIG. 5) is provided with a mold thickness adjustment/extracting mechanism 164 as shown in the upper part of FIG. 6. The mold thickness adjustment/extracting mechanism 164 is the tie bar 1
There is a key 168 on the outer diameter that engages with the screw 150 of No. 16.
Adjustment nut 166 (second adjustment nut) with attached
, a rotary cylinder 170 that can be connected to rotate together by an adjustment nut 166 and a key 168, and a sprocket 172 fixed to the outer periphery of the rotary cylinder 170.
, a cover 174 that is attached to the end housing 114 and sandwiches the rotary cylinder 170 therebetween, a locking block 176 that is attached to the cover 174, and
74 and a locking block 176, and a hydraulic locking cylinder 180 capable of moving the locking plate 178 in the vertical direction in FIG.
6, a spring 182 that always applies an upward force to the locking plate 178 in FIG. . A hole is provided in the cover 174 and locking block 176 to allow the adjustment nut 166 to pass therethrough. The locking plate 178 is
Although the tie bar 116 is allowed to pass, the adjustment nut 166
It has a U-shaped groove that does not allow the passage of. Sprocket 17 provided on the outer periphery of rotating cylinder 170
2 has the same number of teeth as the sprocket 156 and is connected to the aforementioned chain 158. The opposite end of the tie bar 116 (i.e., the fixed platen 11
2) is provided with a tie bar fixing mechanism 18.
8 is provided. Tie bar fixing mechanism 188
is a cutout groove 190 provided in the tie bar 116.
, a locking plate 192 having a U-shaped groove that can be engaged with the notch groove 190, a hydraulic locking cylinder 194 that moves the locking plate 192 up and down as shown in FIG. In FIG. 9, the spring 196 always exerts an upward force. Note that the locking plate 192 is guided by a guide block 198 attached to the fixed platen 112.

Next, a description will be given of a mold replacement operation using the tie bar extraction device of the toggle type mold clamping device having the above configuration. When installing the mold, first the motor 162 is rotated to rotate the adjustment nuts 152 and 166 via the chain 158. Note that the adjusting nut 166 is rotated via a sprocket 172, a rotary cylinder 170, and a key 168. When adjusting nuts 152 and 166 are rotated,
Since these adjustment nuts 152 and 166 are prevented from moving relative to the end housing 114 in the axial direction, the end housing 114 moves in the axial direction. By doing this, the fixed platen 1 when the toggle mechanism 126 is in the most extended state
12 and the movable platen 118 is fixed type 142.
and 5 to 10 mm smaller than the thickness of the movable mold 144. Next, the mold clamping cylinder 120 is operated to retract the rod 122 to bring the movable platen 118 to the farthest position from the fixed platen 112. In this state, hydraulic pressure is supplied to the locking cylinders 180 and 194, and the locking plates 178 and 192 are
to the lower release position. By doing this, the adjustment nut 166 can be moved to the left in FIG. 6, and the locking plate 192 is disengaged from the notch groove 190, so that the tie bar 116 can be moved in the axial direction. becomes. Next, hydraulic pressure is supplied to the extraction cylinder 186 to move the piston rod 186a to the left in FIG. Piston rod 186a and tie bar 116
Since the tie bar 116 is connected by the plate 184, the tie bar 116 moves to the left in FIG. At this time, the adjustment nut 166 also
Move to the left with 6. The cover 174 and the locking block 176 are provided with holes that allow the adjustment nut 166 to pass through.
6 is a cover 174 and a locking block 176
Move to the left without being restricted by.
Note that in this case, the rotary cylinder 170 is restrained by the end housing 114 and the cover 174, and thus maintains its position. In this way, the tie bar 116 is pulled out to the left by the length necessary for mold replacement. Next, the fixed mold 142 and the movable mold 1
44 in a combined state is carried between the fixed platen 112 and the movable platen 118 by a crane or the like, and first the fixed mold 142 is attached to the fixed platen 112 with mounting bolts. Next, the drawing cylinder 186
Hydraulic pressure is supplied to retract the piston rod 186a and return the tie bar 116 to its initial position. When the tie bar 116 returns to the initial position, the adjusting nut 166 is again moved to the rotary cylinder 17 by the key 168.
Concatenated with 0. Next, locking cylinder 1
80 and 194 piston rods 180a and 1
94a is protruded, the adjusting nut 166 is restrained by the locking plate 178, and the tie bar 116 is fixed to the fixed platen 112 by the locking plate 192. Note that after the locking plates 178 and 192 return to the locked position, the supply of hydraulic pressure to the locking cylinders 180 and 194 is stopped, and thereafter the locking plates 178 and 192 are moved by the force of the springs 182 and 196.
is held in the locked position. Next, hydraulic pressure is supplied to the mold clamping cylinder 120 to extend the toggle mechanism 126 and move the movable platen 118 toward the fixed platen 112. When the movable platen 118 contacts the movable mold 144,
The movable mold 144 is attached to the movable platen 118 by means of mounting bolts.
Fixed to. Next, the fixed mold 142 and the movable mold 1
44 cranes, etc. will be disconnected. after that,
retracting toggle mechanism 126 to separate movable mold 144 from fixed mold 142, then activating motor 162 to rotate adjustment nuts 152 and 166;
The end housing 114 is moved to a position where a predetermined mold clamping force is obtained. This completes the mold installation work.

Next, the work to remove the attached mold will be explained. First, the fixed mold 142 and the movable mold 144 are supported by a crane or the like in a tightened state. In this state, the fixed mold 142 and the movable mold 144 are connected to the fixed plate 112 and the movable plate 1, respectively.
Remove the mounting bolt securing 18. Then,
The movable platen 11 is supplied with hydraulic pressure to the mold clamping cylinder 120.
8 to the farthest position from the fixed plate 112. At this time, the movable mold 144 is left on the fixed platen 112 side in combination with the fixed mold 142. Then locking cylinders 180 and 19
4 rods 180a and 194a are pulled in,
The adjustment nut 166 and tie bar 116 are released from the locking plates 178 and 192. In this state, hydraulic pressure is supplied to the extraction cylinder 186 to eject the piston rod 186a. By doing this, the tie bar 116 is pulled out by the length necessary for removing the mold. With the tie bar 116 pulled out, the fixed mold 142 and the movable mold 144 are taken out by a crane or the like. The withdrawal cylinder 186 is then actuated to return the tie bar 116 and adjustment nut 166 to their initial positions. Then locking cylinders 180 and 19
4 and locking plates 178 and 19
2 by adjusting nut 166 and tie bar 116
to restrain. After that, the locking cylinder 180
The supply of hydraulic pressure to and 194 is stopped, and the mold removal work is completed.

As described above, in the tie bar extraction device of the toggle type mold clamping device according to the present invention, the tie bar 116 and the adjustment nut 166 are pulled out as a unit, and after the mold installation or removal work, the tie bar 116 and adjustment nut are left in the same state again. By returning the nut 166 to its initial position, the adjusting nut 166 remains in synchronization with the adjusting nut 152 of the other mold thickness adjusting mechanism 148. Therefore, when the motor 162 is rotated, the adjustment nut 15 is rotated through the chain 158.
2 and 166 rotate under the same conditions, and the end housing 114 moves while maintaining parallelism.

One embodiment of the present invention has been described above, but
The present invention can also be implemented by adding the following changes to this embodiment.

In the described embodiment, only the upper right tie bar 116 in FIG. 5 is made removable, but any tie bar 116 may be removable as required. Furthermore, the number of tie bars that can be pulled out may be two or more instead of just one.

In the illustrated embodiment, the extraction cylinder 186, locking cylinder 180, and locking cylinder 194 are hydraulic cylinders, but other hydraulic cylinders, racks and pinions, etc. may also be used.

In the embodiment described, the locking plate 19
2 is constituted by a single plate having a U-shaped groove, but it may also be constituted by a pair of split plates having semicircular grooves. In this case, the tie bar 116 can be held more securely. The same applies to the locking plate 178.

Additionally, in the described embodiment, the adjustment nut 166
The rotary cylinder 170 is connected by a key 168, but this may also be a spline.

(f) Effects of the invention As explained above, according to the invention, a predetermined number of tie bars are fixed by the tie bar fixing mechanism 188 that can fix or release the tie bars with respect to the fixed platen 112. A tie bar that is connected to the fixed plate and is not provided with a tie bar fixing mechanism is provided with a mold thickness adjustment mechanism 148, and the mold thickness adjustment mechanism is provided with a first adjustment nut 152 that engages with a screw 150 provided on the outer periphery of the tie bar. and the first
It has a nut cover 154 that restrains the adjusting nut in the axial direction with respect to the end housing 114, and the tie bar provided with the tie bar fixing mechanism is provided with a mold thickness adjustment/extraction mechanism 164, which allows mold thickness adjustment/extraction. The extraction mechanism has a second adjustment nut 166 that engages with a screw 150 provided on the outer periphery of the tie bar, and a state in which it rotates together with the second adjustment nut and a state in which it can rotate independently of each other depending on the relative position of the second adjustment nut in the axial direction. a rotary cylinder 170 capable of switching between
It has a locking plate 178 that is movable between a position where the axial movement of the adjustment nut is restrained and a position where it is released, and a pull-out drive mechanism 186 that moves the tie bar in the axial direction. 1st
Since a rotational drive mechanism (motor 162, sprocket 160, chain 158, sprocket 172) that rotates the adjustment nuts in a synchronous manner is provided, the tie bar can be easily removed if necessary. It becomes possible to install molds with larger external dimensions. Moreover, the work of attaching and detaching the mold becomes easier. Furthermore, since the tie bar is not rotated when it is pulled out, the outer periphery of the tie bar is not damaged. Furthermore, since the pulled out tie bar is in the same position before being pulled out and when it is reset after being pulled out, problems such as when a compressive load is applied only to this tie bar will not occur.
Therefore, the mold clamping force acts equally on the four tie bars.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a conventional toggle type mold clamping device, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view taken along the - line in Fig. 2, and Fig. 4 is a sectional view taken along the - line in Fig. 1. 5 is a left side view of FIG. 4, FIG. 6 is a sectional view taken along the line - in FIG. 5, and FIG. is a sectional view taken along the - line in Fig. 6, Fig. 8 is a right side view of Fig. 4, Fig. 9 is a sectional view taken along the - line in Fig. 8, and Fig. 10 is a sectional view taken along the - line in Fig. 9. FIG. 112... fixed plate, 114... end housing, 116... tie bar, 118... movable plate, 1
20...mold clamping cylinder, 122...rod, 12
4...Crosshead, 126...Toggle mechanism, 1
28, 130, 132...link, 134, 13
6,138,140...pin, 142...fixed type, 144...movable type, 146...frame, 1
48...Mold thickness adjustment mechanism, 150...Screw, 152
...Adjusting nut (first adjusting nut), 154...
Nut cover, 156...Sprocket, 158
...Chain, 160 ... Sprocket, 162
... Motor, 164 ... Mold thickness adjustment/extraction mechanism, 1
66... Adjustment nut (second adjustment nut), 168
... Key, 170 ... Rotating tube, 172 ... Sprocket, 174 ... Cover, 176 ... Locking block, 178 ... Locking plate, 1
80... Locking cylinder, 182... Spring, 184... Plate, 186... Pulling cylinder (pulling drive mechanism), 188... Tie bar fixing mechanism, 190... Notch groove, 192... Locking plate, 194 ...Lotsuking cylinder,
196... Spring, 198... Guide block.

Claims (1)

[Claim for Utility Model Registration] A movable platen is supported by a tie bar connected to a fixed platen so as to be movable in the axial direction, and the movable platen is connected to an end housing supported by the tie bar by a toggle mechanism. In a toggle type mold clamping device in which the axial fixing position of the end housing relative to the tie bars is adjustable, a predetermined number of tie bars have a tie bar fixing mechanism that can fix or release the tie bars with respect to the fixed platen. The tie bar is connected to the stationary plate by the tie bar, and the tie bar that is not provided with the tie bar fixing mechanism is provided with a die thickness adjustment mechanism. It has a nut and a nut cover that restrains the first adjustment nut in the axial direction with respect to the end housing, and the tie bar provided with the tie bar fixing mechanism is provided with a mold thickness adjustment/extraction mechanism, and the mold thickness The adjustment/extraction mechanism includes a second adjustment nut that engages with a screw provided on the outer periphery of the tie bar, and a state in which the second adjustment nut rotates integrally with the second adjustment nut and a state in which it can rotate independently of each other depending on the relative position of the second adjustment nut in the axial direction. a rotary cylinder that can be switched; a cover that restricts axial movement of the rotary cylinder; and a locking mechanism that can move the second adjustment nut between a position that restricts and releases the axial movement of the second adjustment nut. It has a plate and a pull-out drive mechanism that moves the tie bar in the axial direction,
A toggle-type mold clamping device with a tie bar extracting device, characterized in that a rotational drive mechanism is provided that rotationally drives a rotating cylinder and a first adjusting nut in a synchronized state.