JPH0224530Y2 - - 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 mechanism. Some direct pressure type mold clamping devices are capable of attaching larger molds by pulling out one or two of the four tie bars when installing and removing molds. 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. The fixed platen 12 and the 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 the crosshead 2 at the tip of the rod 22 of the mold clamping cylinder 20 attached to the end housing 14.
4 via a toggle mechanism 26. The toggle mechanism 26 is comprised of links 28, 30 and 32 which are connected to each other by a pin 34 and connected to the crosshead 24, end housing 14 and movable platen 18 by pins 36, 38 and 40, respectively. are connected together.
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, an adjustment nut 52 that engages with this screw 50, and an adjustment nut 5.
2, a sprocket 56 provided on the outer periphery of the adjusting nut 52, a chain 58 connecting the four sprockets 56 as shown in FIG. 58 and a drive motor 62 that drives a sprocket 60 that meshes with the sprocket 58.

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 device 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 position of the adjustment nut 52 to the four tie bars 16 is the same. 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 tie bar that has been pulled out, 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, resulting in mold clamping force. There is a problem that is no longer constant.
This is because when resetting the tie bars, the tie bars that had 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. Become. 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 during mold clamping.

In addition, the above-mentioned Japanese Patent Publication No. 52-30370 describes a conventional technique in which the nut on the fixed platen side is split into two, the tie bar and the movable platen are connected by a locking device, and the movable platen is moved. Also shown is how to pull out the tie bars. However, in this case, the operation is complicated, the workability is poor, and the equipment cost is high.

(c) Purpose of the invention The present invention makes it possible to pull out the tie bars of a toggle type mold clamping device with simple operation and structure, and makes it possible to mount a mold with larger external dimensions than conventional ones for the same tie bar spacing. The purpose is to make mold replacement work easier and to solve the conventional problems mentioned above at the same time.

(d) Structure of the invention The toggle type mold clamping device with a tie bar extraction device according to the invention includes a cylinder provided corresponding to each tie bar so as to move integrally with the end housing, and a cylinder formed integrally with each tie bar and each When the piston is inserted into the cylinder, a gap is formed between the piston and each tie bar when hydraulic pressure is supplied to the inner diameter part, and a tight fit is formed between each tie bar when the hydraulic pressure from the inner diameter part is discharged. and a fixing member that prevents movement of each cylindrical member in the axial direction with respect to the end housing, and at least one of the cylinders has a piston stroke greater than or equal to the thickness of the mold used. The tie bar corresponding to the cylinder having a piston stroke greater than the mold thickness is attached to the fixed plate by a tie bar fixing mechanism that can fix or release the tie bar in the axial direction from the fixed plate. The tie bar fixing mechanism includes a notch groove provided in the tie bar, a gate plate that can fit into the notch groove, and a position where the gate plate fits into the notch groove and a released position. It consists of a gate plate drive device that moves the gate plate between the two.

(e) Examples Examples of the present invention will be described below with reference to Nos. 4 to 11 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 and 116'. A movable platen 118 supported movably in the axial direction with respect to tie bars 116 and 116' is connected to a crosshead 124 at the tip of a rod 122 of a mold clamping cylinder 120 attached to an end housing 114.
and is connected via a toggle mechanism 126. Toggle mechanism 126 includes links 128, 130 and 13
These links are connected to pin 1.
34 and are connected to the crosshead 124, end housing 114 and movable platen 118 by pins 136, 138 and 140, respectively. A fixed die 142 is attached to the fixed platen 112, and a movable die 144 is attached to the movable platen 118. The end housing 114 is movably provided on the frame 146 and has a mold thickness adjustment mechanism 14 shown in FIGS. 6 and 7.
8 and mold thickness adjustment/extracting mechanism 148' shown in FIG.
The attachment position with respect to the tie bars 116 and 116' can be adjusted by.

The mold thickness adjustment mechanism 148 is shown enlarged in FIG.
The mold thickness adjustment mechanism 148 is connected to the end housing 114.
a cover 150 attached to the
a cylindrical member 152 provided inside the cover 1;
50, and a piston 156 that is integrally formed at the end of the tie bar 116 and inserted into the inner diameter of the adjustment cylinder 154. Two oil chambers 158 defined by the piston 156 of the adjustment cylinder 154
and 160 have ports 162 and 164 to which hydraulic pressure can be supplied and discharged, respectively. The cylindrical member 152 is restrained from moving in the axial direction inside the cover 150. Further, the tie bar 116 passes through the inner diameter portion of the cylindrical member 152. The inner diameter of the cylindrical member 152 is provided with a helical or circumferential groove 166 that facilitates the supply of hydraulic pressure to the inner diameter. Hydraulic pressure can be supplied to the inner diameter portion of the cylindrical member 152 from ports 168 and 170 provided in the cover 150. Cylindrical member 15
The inner diameter of the cylindrical member 152 is smaller than the outer diameter of the tie bar 116 when no hydraulic pressure is supplied to the inner diameter portion of the cylindrical member 152 . That is, the cylindrical member 152 is tightly fitted to the tie bar 116 (the state shown in FIG. 6). On the other hand, when hydraulic pressure is supplied from ports 168 and 170, cylindrical member 152 expands to form a gap between its inner diameter and tie bar 116 (the state shown in FIG. 7).

The mold thickness adjustment/extracting mechanism 148' shown in FIG.
It has the same configuration as the mold thickness adjustment device 148, except that the length of the adjustment/pull-out cylinder 154' is longer than that of the adjustment cylinder 154 (in order to distinguish it from the mold thickness adjustment mechanism 148, the mold thickness Corresponding parts of the adjustment/extraction mechanism 148' are indicated with a '' appended to the reference numerals). For this reason, the mold thickness adjustment/pulling mechanism 14
The stroke of the piston 156' of 8' is longer, allowing a stroke longer than at least the thickness of the molds (fixed mold 142 and movable mold 144).

As shown in FIGS. 9 to 11, a tie bar fixing mechanism is provided at the opposite end of the tie bar 116' (that is, the end penetrating the fixed plate 112) where the mold thickness adjustment/extracting mechanism 148' is provided. 188 are provided. The tie bar fixing mechanism 188 includes a notch groove 190 provided in the tie bar 116', a gate plate 192 having a U-shaped groove that can be engaged with the notch groove 190, and a gate plate 192 that can be moved up and down in FIG. Hydraulic gate cylinder 19
4, and a spring 196 that always applies an upward force to the gate plate 192 in FIG. Note that the gate plate 192 is attached to the fixed plate 1
It is guided by a guide block 198 attached to 12. When the gate plate 192 is engaged with the cutout groove 190 of the tie bar 116', the tip of the tie bar 116' abuts against the inner wall of the guide block 198.

Mounting plate 17 fixed to end housing 114
2 is a limit switch 174 for detecting completion of mold clamping.
and a limit switch 176 for setting mold clamping force. Both limit switches 174 and 176 are actuated by a cam 178 mounted on crosshead 124. The mold clamping completion detection limit switch 174 is provided to operate in a state immediately before the toggle mechanism 126 is fully extended. Furthermore, the mounting position of the mold clamping force setting limit switch 176 is adjustable.

Next, a description will be given of a mold replacement operation of a toggle type mold clamping device having a tie bar extraction device having the above-mentioned configuration.

When installing a mold, first, ports 168 and 170 of the mold thickness adjustment mechanism 148 and ports 168' and 17 of the mold thickness adjustment/extracting mechanism 148' are installed.
Hydraulic pressure is supplied to cylindrical members 152 and 15
2' and port 1 of the adjustment cylinder 154.
62 or port 164 and port 162' or 164' of adjustment and withdrawal cylinder 154' to move end housing 114 axially. By doing this, the toggle mechanism 126
The distance between the fixed platen 112 and the movable platen 118 when the
Make it 5 to 10 mm smaller than the thickness of 44. Once the position of the end housing 114 is set, the supply of hydraulic pressure to the inner diameter of the cylindrical members 152 and 152' and to the adjustment cylinder 154 and the adjustment/extraction cylinder 154' is stopped. Next, the mold clamping cylinder 120
is operated to retract the rod 122, and the movable platen 118 is brought to the farthest position from the fixed platen 112. In this state, ports 168' and 17
0' to expand the cylindrical member 152', and supplying hydraulic pressure to the gate cylinder 194;
Move the gate plate 192 downward to the release position. By doing this, the cylindrical member 152'
The restraint of the tie bar 116' is released, and the gate plate 192 is
Since the engagement of the tie bar 116' is released, the tie bar 116' becomes movable in the axial direction. Then, hydraulic pressure is supplied to the port 164 of the adjustment/extraction cylinder 154';
Move the tie bar 116' to the left in FIG. In this way, the tie bar 116' is pulled out to the left by the length necessary for replacing the mold. Next, fixed type 1
42 and the movable mold 144 in combination are transported 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 bolts. During this time, for safety reasons, the supply of hydraulic pressure to the cylindrical member 152' and the gate cylinder 194 is stopped, and the fixed mold 14
After installing 2, supply hydraulic pressure again. Hydraulic pressure is then applied to port 162' of adjustment and extraction cylinder 154' to return tie bar 116' to its initial position.
When the tie bar 116' returns to its initial position and its tip hits the inner wall of the guide block 198,
Piston rod 194a of gate cylinder 194
The tie bar 116' is fixed to the fixed plate 112 by the gate plate 192. Also,
The supply of hydraulic pressure to the inner diameter portion of the cylindrical member 152' is stopped, and the tie bar 116' and the cylindrical member 152' are tightly fitted. In addition, the gate plate 192
After returning to the lock position, the gate cylinder 194
Stop supplying hydraulic pressure to the spring 19.
6 forces hold gate plate 192 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 comes into contact with the movable mold 144, the movable mold 144 is fixed to the movable platen 118 by the mounting bolt. Next, the fixed mold 142 and the movable mold 144 are disconnected from the crane. After that, the mold clamping cylinder 120 is operated to move the movable mold 144 to the fixed mold 14.
2 while pressing the cylindrical members 152 and 152'
By supplying hydraulic pressure to the inner diameter of the tie bars 116 and 1
16', and supply hydraulic pressure to the ports 162 and 162' to connect the end housing 1.
14 to the left in FIG. This movement of the end housing 114 to the left continues until the mold clamping force setting limit switch 176 is operated by the cam 178. When the mold clamping force setting limit switch 176 is activated, the cover 150
and 150' ports 168, 170, and 16
8', 170' is discharged, the cylindrical members 152 and 152' and the tie bars 116 and 116' are connected by interference fit, and the position of the end housing 114 relative to the tie bars 116 and 116' is adjusted. Fix it. By doing so, the end housing 114 is set at a position where a predetermined mold clamping force can be obtained. This completes the mold installation work. The position of the limit switch 176 for setting the mold clamping force is the same as that of the mold clamping cylinder 120.
It is determined based on theoretical calculations or actual measurements of the mold clamping force so that the mold clamping force by the toggle mechanism 126 becomes a predetermined value. Therefore, the setting of the mold clamping force is completed at the same time as the mold thickness is adjusted.

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 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 11, respectively.
Remove the mounting bolts securing 8. Next, hydraulic pressure is supplied to the mold clamping cylinder 120 to close the movable platen 118.
is moved 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 a combined state with the fixed mold 142. Next, the rod 19 of the gate cylinder 194
4a to release the tie bar 116' from being restrained by the gate plate 192. Further, hydraulic pressure is applied to the inner diameter portion of the cylindrical member 152' to release the connection with the tie bar 116'. In this state, hydraulic pressure is supplied to the port 164' of the adjusting/extracting cylinder 154', and 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. Next, adjust
Operate the pull-out cylinder 154' to remove the tie bar 11.
Return 6' to the initial position. Next, the gate cylinder 194 is operated to release the gate plate 19.
2 restrains the tie bar 116'. after that,
The supply of hydraulic pressure to the gate cylinder 194, the cylindrical member 152', and the adjustment/pulling cylinder 154' is stopped, and the mold removal work is completed.

As described above, in the toggle type mold clamping device with tie bar pullout device according to the present invention, the tie bar 116' is pulled out to perform mold installation or removal work, and after that, the gate plate 192 engages with the notch groove 190. Tie bar to position 11
Since the tie bar 116' is returned to its original position, the tie bar 116' is at the same position before and after the mold replacement work, and the end housing 114 moves while maintaining parallelism when adjusting the mold thickness.

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

In the embodiment described, only the upper right tie bar 116' in FIG. 5 is made removable, but any tie bar may be removable as required. In addition, the tie bar that can be pulled out is 1
It is also possible to use not only books but two or more books (for example, two books on the top side or two books on one side).

In the illustrated embodiment, the gate cylinder 194 is a hydraulic cylinder, but other hydraulic cylinders, rack and pinions, etc. may also be used.

In the embodiment described, the gate plate 192 is comprised of a single plate with a U-shaped groove, but it could also be comprised of a pair of split plates with semicircular grooves. . in this case,
The tie bar 116 can be held more securely.

(f) Effect of the invention As explained above, according to the invention, the movable platen is supported by the tie bars connected to the fixed platen so as to be movable in the axial direction, and the movable platen is supported by the end housing supported by the tie bars. In a toggle-type mold clamping device that adjusts the distance between the fixed platen and the movable platen by adjusting the axial fixing position of the end housing with respect to the tie bar, Cylinders 154, 154' are movably provided corresponding to each tie bar, and a piston 15 is integrally formed with each tie bar and inserted into each cylinder.
6,156', a cylindrical member with a gap formed between each tie bar when hydraulic pressure is supplied to the inner diameter part, and tightly fitted to each tie bar when the hydraulic pressure in the inner diameter part is discharged. 152,15
2', and a fixing member (cover 15) that prevents each cylindrical member from moving in the axial direction relative to the end housing.
0,150'), at least one of the cylinders (154') has a piston stroke greater than or equal to the mold thickness, and has a piston stroke greater than or equal to the mold thickness. The tie bar 116' corresponding to the cylinder is connected to the stationary platen by a tie bar fixing mechanism 188 that can fix or release the tie bar from the stationary platen.
90, a gate plate 192 that can fit into the notch groove, and a gate plate drive device 194 that moves the gate plate between the position where the gate plate fits into the notch groove and the released position. The tie bars can be easily removed if necessary, making it possible to attach a mold with a larger external dimension than a conventional mold clamping device with the same tie bar spacing. Furthermore, the work of attaching and removing the mold becomes easier. Further, since the tie bar is not rotated when it is pulled out, the outer periphery of the tie bar is not damaged, and a mechanism for rotating the tie bar is not required. Furthermore, the pulled out tie bar is in the same position before being pulled out and at the time of reset after being pulled out, and 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. Further, the tie bar pulling device according to the present invention allows easy work of pulling out and resetting the tie bar, and has good workability. In other words, the tie bar fixing mechanism on the fixed platen can fix and release the tie bar by operating the gate plate using the gate plate drive device, and the work is much simpler than when using split nuts. . Further, since the end housing and the tie bar are fixed and released using the above-mentioned cylindrical member, the operation is much simpler than when nuts are used. Further, when pulling out the tie bar, there is no need for the work of connecting the movable platen and the tie bar.

[Brief explanation of the drawing]

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. A diagram showing a toggle type mold clamping device with a tie bar extraction device which is an embodiment of the invention, FIG. 5 is a left side view of FIG. 4,
6 is a sectional view taken along the - line in FIG. 5, FIG. 7 is a view showing the expanded state of the cylindrical member, FIG. 8 is a sectional view taken along the - line in FIG. 6, and FIG. 9 is a sectional view taken along the - line in FIG. 10 is a sectional view taken along the - line in FIG. 9, and FIG. 11 is a sectional view taken along the line XI--XI in FIG. 10. 112... Fixed plate, 114... End housing, 116, 116'... Tie bar, 118...
Movable platen, 120...mold clamping cylinder, 122...rod, 124...crosshead, 126...toggle mechanism, 128, 130, 132...link, 1
34,136,138,140...Pin, 142
...Fixed type, 144...Movable type, 146...Frame, 148...Mold thickness adjustment mechanism, 148'...Mold thickness adjustment/extraction mechanism, 150,150'...Cover (fixed member), 152,152 '...Cylindrical member, 1
54...Adjustment cylinder, 154'...Adjustment/extraction cylinder, 156, 156'...Piston, 18
8... Tie bar fixing mechanism, 190... Notch groove, 192... Gate plate, 194... Gate 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 via a toggle mechanism. , in a toggle-type mold clamping device that adjusts the distance between the fixed platen and the movable platen by adjusting the axial fixing position of the end housing with respect to the tie bar, there is a toggle type mold clamping device that adjusts the distance between the fixed platen and the movable platen by adjusting the axial fixing position of the end housing with respect to the tie bar. When hydraulic pressure is supplied to the inner diameter part, a gap is formed between the provided cylinder, the piston that is integrally formed with each tie bar and inserted into each cylinder, and each tie bar, and the hydraulic pressure in the inner diameter part is discharged. a cylindrical member that is tightly fitted to each tie bar in the closed state, and a fixing member that prevents each cylindrical member from moving in the axial direction with respect to the end housing, and at least one of the cylinders is used. The tie bar corresponding to the cylinder having a piston stroke greater than or equal to the mold thickness fixes or releases the tie bar in the axial direction with respect to the fixed platen. The tie bar fixing mechanism is connected to the stationary platen by a tie bar fixing mechanism that can
A notch groove provided in the tie bar, a gate plate that can fit into the notch groove, and a gate plate drive device that moves the gate plate between a position where the gate plate fits into the notch groove and a released position. A toggle type mold clamping device with a tie bar pulling device.