JPH0131465Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an injection molding machine, and particularly to a structure for clamping a fixed plate and a movable plate to which a pair of molds are respectively fixed.

BACKGROUND ART Injection molding machines have been used that produce molded products by press-fitting heated and fluidized synthetic resin into a cavity formed by a pair of molds. In such an injection molding machine, a pair of molds is generally fixed to a fixed platen and a movable platen, which are held in a fixed opposing relationship by a plurality of tie bars, and are connected to the tie bars by a mold opening/closing cylinder. The pair of molds are brought into close contact with each other to form a cavity.

By the way, in such an injection molding machine,
Since the high-pressure synthetic resin is press-fitted into the cavity, it is necessary to firmly connect and fix the pair of molds using a mold clamping mechanism or the like. In order to maintain the opposing relationship between the pair of molds in a constant state even when such a large force is applied, four or more tie bars may be provided at the four corners of the fixed platen and the movable platen. many.

Technical Issues However, when a large number of tie bars are arranged in this way, the tie bars become a hindrance when taking out the finished molded product or replacing the molds fixed to the fixed platen and the movable platen. There was a problem that the work became troublesome as it got older.

For this reason, in Japanese Patent Application Laid-open No. 51-73066,
There is a structure in which two locking members are provided between the fixed platen and the movable platen in place of the tie bars, and the engagement of these locking members allows them to function as tie bars when closing the mold. However, since the rotational power source for engaging the lock member and the forward/backward power source are separately provided, the forward/backward operation of the lock member and the rotational operation for engagement are required. There is a problem that there is a time delay between the two, and the power for mold clamping is also separate from the rotary power source. Of course, in this case, the locking member moves forward and backward in conjunction with the mold clamping operation by a mold clamping mechanism equipped with a motor, but such a mold clamping mechanism simultaneously opens the mold and closes the mold. Since it also performs a closing operation, it was inevitable that the mold clamping mechanism would be enlarged in order to ensure a large mold opening/closing stroke and to exert a large mold clamping force.

In view of the above-mentioned circumstances, the present invention provides an injection molding machine in which the tie bars are omitted so that the product can be easily removed and the mold replaced. A mechanism or device capable of advancing and retracting the two locking members provided between the two locking members and rotating the locking members for male and female fitting together, and also capable of performing the mold clamping operation using one cylinder. to provide
This was done as a technical issue.

Solution In order to achieve the above technical problem, the injection molding machine according to the present invention includes a first locking member having a T-shaped male portion at the end on either the fixed platen or the movable platen. On the other hand, a second locking member, which can accommodate the T-shaped male part and has a female part at an end that cannot be removed by a predetermined rotation about the axis thereof, is capable of being male-femally fitted into the first locking member. A locking member is disposed on the other of the fixed plate or the movable plate, and an advancing/retracting mechanism for moving one of the locking members forward and backward in a direction parallel to the mold clamping direction is provided, and the forward movement by the advancing/retracting mechanism is performed. In an injection molding machine in which the two locking members are fitted together male and female to clamp the fixed platen and the movable platen, the advancing/retracting mechanism is configured such that (a) a cylinder bore having a longitudinal shape (b) a first cylinder body fitted into the cylinder bore so as to be movable in the axial direction but not rotatable about the axis, and forming two hydraulic pressure chambers at the front and rear in the cylinder bore; (c) one hydraulic pressure chamber formed in front of the first piston is inserted in the axial direction of the cylinder body, and one end is screwed to the first piston. (d) a second piston whose other end protrudes outward from the cylinder body and to which one of the two locking members is fixed; a stopper mechanism that prevents the piston from protruding beyond a certain dimension from the main body; By moving the first piston forward and backward integrally with the piston, and moving the first piston relative to the second piston at a forward position where the second piston is prevented from protruding by the stopper mechanism, The second piston is rotationally driven by the screw action of the first and second pistons, so that the two locking members are mated with each other.

Function In the above-mentioned injection molding machine, the first and second locking members are usually separated to separate the fixed platen and the movable platen. ), the first and second locking members are brought close to each other and engaged, and the fixed platen and the movable platen are strongly clamped.

Embodiment Next, in order to clarify the present invention more specifically, one embodiment of the present invention will be described in detail based on the drawings.

First, in FIGS. 1 and 2, reference numeral 10 denotes a pair of frames arranged in parallel on a base (not shown), and a rail 12 is fixed on each of the frames 10. As shown in FIG. A fixed platen 14 and a movable platen 16 are disposed facing each other on the rail 12, and a pair of molds 1 are disposed on their opposing surfaces.
8 and 20 are fixed respectively. The fixed platen 14 is fixed at a predetermined position on the rail 12, while the movable platen 16 has a pair of legs 22 having a substantially L-shaped cross section that engage with the rail 12, as is clear from FIG. This makes it possible to move along the rail 12. and,
The movable platen 16 is driven toward and away from the fixed platen 14 by a mold opening/closing cylinder 26 fixed to a bracket 24.

On the opposing surfaces of the fixed platen 14 and the movable platen 16, there are four female members 28 and four male members 30, respectively.
is installed. As shown in detail in FIGS. 3 and 4, one female member 28 has a cylindrical shape with a notch 32 formed from the tip toward the axial direction, and further has a cylindrical shape with a notch 32 formed on both sides of the notch 32. On the wall,
Recesses 34 each having an arc shape are provided. As shown in detail in FIGS. 5 and 6, one male member 30 includes a cylindrical shaft portion 36 and a small diameter portion coaxially formed at the tip of the shaft portion 36. 38, and an engaging portion 40 provided at the tip of the small diameter portion 38 so as to protrude in the radial direction. The diameter of the small diameter portion 38 is set smaller than the width of the notch 32 of the female member 28, the length of the engaging portion 40 is larger than the width of the notch 32, and the length of the engaging portion 40 is set smaller than the width of the notch 32, and It is set smaller than the dimension between the bottoms.

As shown in FIG. 7, the four female members 28 are mounted in mounting holes 42 formed at the four corners of the stationary platen 14 via mold clamping cylinders 44. Furthermore, the four male members 30 are fitted into mounting holes 45 (see FIG. 2) formed at the four corners of the movable platen 16 so that their shaft portions 36 are movable in the axial direction but cannot be rotated around the axis. By being fitted together, they are attached so as to face the female member 28, respectively.

As shown in detail in FIG. 3, the mold clamping cylinder 44 includes a cylinder body 48 in which a cylindrical cylinder bore 46 is formed. For manufacturing reasons, the cylinder body 48 is composed of a cylindrical body 50 and a pair of lids 52 and 54 fixed to close openings at both ends of the cylinder 50. A cylindrical projection 56 is provided on one lid 52 and projects outward on the axis of the cylinder body 48, and a screw 58 is formed on the outer peripheral surface of the projection 56.

Inside the cylinder bore 46 of the cylinder body 48,
A first piston 60 is fitted in a fluid-tight and slidable manner, and two hydraulic chambers 62 and 64 are provided in front and behind the first piston 60 in the cylinder bore 46.
is formed. The first piston 60 has a small diameter portion and a large diameter portion, and a plurality of guide rods 66 disposed within the cylinder bore 46 parallel to the axis of the cylinder body 48 are slidable on the large diameter portion. It is forced to be inserted. Thereby, the first piston 60 is allowed to move in the axial direction, but is prevented from rotating around the axis. Note that passages 68 and 70 are provided in the hydraulic pressure chambers 62 and 64, respectively.
Hydraulic fluid is supplied through the

The first piston 60 has an insertion hole 72 formed in its axis with a female thread, and one end of a second piston 74 is screwed into the insertion hole 72. The second piston 74 is inserted into the hydraulic pressure chamber 62 in the axial direction of the cylinder body 48, and the other end thereof is inserted through the lid 54 and extends outward from the cylinder body 48. The female member 28 is fixed. First piston 60 of second piston 74
A male thread 76 is erected on the end surface of the screwed side and a nut 78 is attached to it, thereby preventing the first piston 60 from being relatively detached from the second piston 74. . Further, a flange 80 is provided at an intermediate position of the second piston 74, and by contacting the lid 54, the second piston 74 is prevented from protruding beyond a certain dimension from the cylinder body 48. That is, this flange 80 constitutes a stopper mechanism. Note that the flange 80 is provided with a plurality of notches 82, and the flange 80 is connected to the lid body 5.
4, hydraulic fluid can be supplied into the hydraulic pressure chamber 62 through the passage 68.

A spring receiver 84 is disposed on the side of the flange 80 facing the first piston 60, and a compression coil spring 8 is disposed between the flange 80 and the first piston 60.
6 is inserted. As a result, the second piston 74 is driven forward and backward together with the first piston 60, with its nut 78 always in contact with the first piston 60.

Here, the first and second pistons 60 and 74 are screwed together as described above, but the pitch of their threads is very large.
It is installed at an angle of approximately 45° with respect to the axial direction. Therefore, when the second piston 74 is moved forward together with the first piston 60 and its flange 80 is brought into contact with the lid 54, the first piston 60 is further moved forward by the biasing force of the compression coil spring 86. When the second piston 74 is moved forward against this, the second piston 74 is driven to rotate around the axis by the screw action.

Note that the second piston 7 of the first piston 60
4 is restricted by the end surface of the small-diameter side of the first piston 60 coming into contact with the spring receiver 84, but based on the relative movement between the two during this period, the second piston 74 moves approximately 90 degrees. It is designed to be rotated. Further, in the state in which the second piston 74 is rotated in this manner, the engaging portion 40 of the male member 30 is fitted into the notch 32 of the female member 28 fixed to the second piston 74. Both members 28 and 30 are attached so that they can be inserted.

Returning to FIG. 7, the mold clamping cylinder 44 configured as described above is slidably fitted into the mounting hole 42 of the stationary platen 14, but rotation around its axis is prevented. It is blocked by key 88.
Further, a sprocket 90 is screwed into a screw 58 formed on the protrusion 56 of the mold clamping cylinder 44, and the sprocket 90 is rotationally driven by a motor 92. Thereby, the amount of protrusion of the clamping cylinder 44 relative to the fixed platen 14 can be changed depending on the thickness of the mold 18 and the like. In addition, four mold clamping cylinders 4
The sprockets 90 screwed into the sprockets 4 and 4 respectively are
It is adapted to be rotationally driven by two motors 92.

On the other hand, each of the male members 30 also has a movable platen 16.
A male screw 94 is erected to protrude rearward from the sprocket 94, and a sprocket 98 rotated by a single motor 96 is screwed into each sprocket (see FIG. 1). Thereby, the amount of protrusion of the male member 30 with respect to the movable platen 16 can be changed depending on the thickness of the mold 20 and the like.

Next, the operation of the injection molding machine configured as above will be explained.

First, the movable platen 16 is opened by the mold opening/closing cylinder 26.
The molds 18 and 20 are fixed to the fixed platen 14 and the movable platen 16, respectively, while the molds 18 and 20 are held in a retracted position away from the fixed platen 14.
Since only the female member 28 and the male member 30 are attached to opposing surfaces between the fixed platen 14 and the movable platen 16, the molds 18 and 20 can be easily attached. Then, the mold 1
The amount of protrusion of the female member 28 and the male member 30 is adjusted by the motors 92 and 96 according to the thickness dimensions of the female member 28 and the male member 30. Note that the dimensions of this protrusion amount will be described later.

Thereafter, when hydraulic fluid is supplied into the hydraulic pressure chamber 64 of the mold clamping cylinder 44, the first piston 60 is moved forward while being guided by the guide rod 66, and at the same time, the second piston 74 also has its flange 80 connected to the lid. It is advanced together with the first piston 60 until it abuts against the piston 54. When the flange 80 comes into contact with the lid 54, further advancement of the second piston 74 is prevented. FIG. 8 shows this state.

When more hydraulic fluid is supplied into the hydraulic pressure chamber 64, only the first piston 64 is advanced and the second piston 74 is rotated. When the end surface of the small diameter portion of the first piston 60 comes into contact with the spring receiver 84, the first piston 60 is prevented from moving further, and the second piston 74 is moved approximately 90 degrees higher than the original state. It will be in a rotated state. As a result, the female member 28 fixed to the second piston 74 is connected to the male member 30 attached to the movable platen 16.
can be mated with. FIG. 9 shows this state.

In this state, when the movable platen 16 is moved forward in the direction approaching the fixed platen 14 by the mold opening/closing cylinder 26, the engaging portion 40 of the male member 30 attached to the movable platen 16 engages with the notch 3 of the female member 28. It is fitted inside. The engaging portion 40 indicated by a two-dot chain line in FIG. 9 shows this state.
At this time, the molds 18 and 20 fixed to the fixed platen 14 and the movable platen 16 are brought into contact with each other or brought close to each other by a distance sufficiently smaller than the movement stroke of the second piston 74. It is being The protruding amounts of the female member 28 and male member 30 described above are thus adjusted by the motors 92 and 96.

In this state, if the pressure of the hydraulic fluid in the hydraulic chamber 64 is lowered, in other words, if the hydraulic fluid in the hydraulic chamber 64 is allowed to flow out, the first piston 60 will follow the biasing force of the compression coil spring 86. and is retracted until it abuts against the nut 78. As a result, the second piston 74 is rotated approximately 90 degrees and returned to the state shown in FIG. Relative movement in the axial direction is prevented, and the female member 28 and the male member 30 are mated together. That is, the female member 28 and the male member 30 form two locking members that can be fitted into a male and a female. Note that it is also possible to retract the first piston 60 by supplying a hydraulic pressure higher than the hydraulic pressure in the hydraulic chamber 64 into the hydraulic pressure chamber 62, and in that case, the compression coil spring 86 can be omitted. can.

Thereafter, when hydraulic fluid with a sufficiently higher hydraulic pressure than the hydraulic pressure in the hydraulic chamber 64 is supplied into the hydraulic chamber 62, the second piston 74 is retracted together with the first piston 60, and the male member 30 is pulled toward the fixed platen 14 side. As a result, the pair of molds 18 and 20
are brought into close contact with each other to form a cavity (not shown). Here, the hydraulic pressure chamber 6
The hydraulic pressure of the hydraulic fluid supplied into the molds 18 and 20 remains constant even when high-pressure synthetic resin is press-fitted into the cavities of the molds 18 and 20 from an injection device (not shown).
The pressure is set at a level that does not impair the close contact of the parts 20 and 20.

A synthetic resin in a fluid state is press-fitted into the cavity, and after it is cooled and solidified, the hydraulic pressure of the hydraulic fluid in the hydraulic chamber 62 is lowered, and the hydraulic fluid in the hydraulic chamber 64 is lowered.
When hydraulic fluid is supplied into the hydraulic pressure chamber 64, the first and second pistons 60 and 74 are moved forward to the state shown in FIG. The piston 74 is rotated to the state shown in FIG. 9. Then, the movable platen 16 is moved backward by the mold opening/closing cylinder 26, the molds 18 and 20 are opened, and the solidified molded product is taken out. At this time, the female member 28 and the male member 30 are separated. Therefore, the molded product can be easily removed. At the same time, the mold clamping cylinder 44
The hydraulic pressure of the hydraulic fluid in the hydraulic pressure chamber 64 is lowered, and the hydraulic fluid is supplied into the hydraulic pressure chamber 62, and the first and second pistons 60 and 74 are returned to their original states shown in FIG. It will be done.

In this way, in the injection molding machine of this embodiment, first, the fixed platen 1 is moved by the mold opening/closing cylinder 26.
4 and the movable platen 16 are brought close to each other, and then the female member 28 and the male member 3 are moved together by the mold clamping cylinder 44.
0 are male-female fitted to form a pair of molds 18 and 2.
0 are firmly brought into close contact with each other while maintaining a constant facing relationship. Therefore, unlike conventional injection molding machines, there is no need to provide multiple tie bars that constantly connect the fixed plate and movable plate in order to maintain the opposing relationship in a constant state. This makes it easier to take out the finished product or replace the molds 18 and 20 fixed to the fixed platen 14 and movable platen 16.

Furthermore, since the opening/closing and mold clamping of the molds 14 and 16 are performed separately by the mold opening/closing cylinder 26 and the mold clamping cylinder 44, the mold opening/closing cylinder 26 simply drives the movable platen 16 back and forth. It does not require a particularly large operating force. On the other hand, regarding the mold clamping cylinder 44, since it is sufficient to simply firmly clamp the fixed platen 14 and the movable platen 16, the tightening stroke is very small, the cylinder can be configured compactly, and the time required for mold clamping is reduced. Becomes shorter.
In particular, in this embodiment, since the four mold clamping cylinders 44 are arranged at the four corners of the fixed platen 14, the mold 1
8 and 20 can be clamped well with a small operating force.

Furthermore, the female member 28 and the male member 3 of this embodiment
0, since the amount of protrusion from the fixed platen 14 and the movable platen 16 can be adjusted by motors 92 and 96, respectively, the molds 18 and 2
The thickness dimension of 0 can be freely set.

Although one embodiment of the present invention has been described above based on the drawings, the present invention can also be implemented in other embodiments.

For example, in the embodiment described above, the female member 28 is advanced by the mold clamping cylinder 44 and further rotated to be mated with the male member 30. 30 may be configured to move forward/backward and/or rotate to engage/disengage the female member 28.

Furthermore, in the above-mentioned embodiment, the female member 28 and the male member 30 are arranged at the four corners of the fixed platen 14 and the movable platen 16, respectively, but the location and number of these members 28 and 30 can be changed as necessary. All you have to do is set it appropriately.

Furthermore, in the above embodiment, the mold opening/closing cylinder 26
As a result, the movable platen 16 approaches the fixed platen 14.
Although it is designed to be driven remotely, it is also possible to employ other driving means such as a motor. Note that the mold clamping cylinder 44 has a large operating stroke.
If you use the mold clamping cylinder 4 for mold clamping and mold opening/closing,
You can also do it with only 4.

Furthermore, in the embodiment described above, the female member 28 is fixed to the second piston 74 of the mold clamping cylinder 44 disposed on the fixed platen 14, but the male member 30
Of course, the mold clamping cylinder 44 may be fixed to the second piston 74, or the mold clamping cylinder 44 may be disposed on the movable platen 16.

The above-mentioned invention is merely an example of the present invention, and it goes without saying that the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit thereof.

Effects of the invention As detailed above, in the injection molding machine of the invention, when the fixed platen and the movable platen are separated, there are no tie bars or the like that get in the way between them, so that the molded finished product is This makes it easier to take out and replace the mold. Moreover, since the locking member is moved forward and backward and rotated by a single drive source (mold clamping cylinder), the mechanism is simple, time delays in operation are eliminated, and mold clamping is performed by the drive source. Therefore, the mold clamping cylinder, which is the driving source, only needs to firmly tighten the fixed plate and the movable plate, and the tightening stroke can be made small, the cylinder can be made compact, and the movable plate can be tightened. The mold opening/closing cylinder that is driven also does not require a large operating force, and other excellent effects can be enjoyed.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a part of an injection molding machine which is an embodiment of the present invention. FIG. 2 is a front view of the movable platen shown in FIG. 1. FIG. 3 is a sectional view of a mold clamping cylinder provided in the injection molding machine of FIG. 1 and a female member fixed to the mold clamping cylinder. FIG. 4 is a cross-sectional view of FIG. 3. FIG. 5 is a front view showing the tip of the male member provided in the injection molding machine of FIG. 1. FIG. 6 is a cross-sectional view of FIG. 5. FIG. 7 is a diagram showing the arrangement of the mold clamping cylinders in the injection molding machine of FIG. 1, and is a partial sectional view of the stationary platen. FIG. 8 is a sectional view showing one operating state of the mold clamping cylinder of FIG. 3. FIG. 9 is a sectional view showing still another operating state of the mold clamping cylinder shown in FIG. 3;
FIG. 7 is a diagram illustrating a fitted state between a female member and a male member. 14: Fixed plate, 16: Movable plate, 18, 20: Mold, {28: Female member, 30: Male member} (lock member), 44: Mold clamping cylinder (advance/retreat mechanism), 46:
Cylinder bore, 60: first piston, 62,6
4: Hydraulic pressure chamber, 74: Second piston, 80: Flange (stopper mechanism).

Claims (1)

[Scope of Claim for Utility Model Registration] A first locking member having a T-shaped male portion at the end is disposed on either the fixed platen or the movable platen, and a first locking member capable of accommodating the T-shaped male portion and having an axis thereof having a female part at the end that cannot be removed by a predetermined rotation of the
A second lock member capable of being male and female fitted to the first lock member is disposed on the other of the fixed plate or the movable plate, and one of the lock members is arranged in a direction parallel to the mold clamping direction. In an injection molding machine, the injection molding machine is provided with an advancing/retracting mechanism that moves forward and backward, and the two locking members are fitted into a male and female by the forward movement of the advancing/retracting mechanism, thereby clamping the fixed platen and the movable platen, The advancing/retracting mechanism includes a cylinder body having a longitudinal cylinder bore therein, and a cylinder body fitted into the cylinder bore so as to be movable in the axial direction but not rotatable around the axis, and having two cylinders at the front and rear inside the cylinder bore. A first piston forming a hydraulic pressure chamber; and one hydraulic pressure chamber formed in front of the first piston is disposed so as to be inserted in the axial direction of the cylinder body, and one end portion is inserted into the first hydraulic pressure chamber. a second piston that is screwed onto the first piston, and whose other end protrudes outward from the cylinder body to fix one of the two locking members; the second piston; a stopper mechanism that prevents the piston from protruding beyond a certain dimension from the cylinder body; The first piston is moved forward and backward integrally with the first piston, and the first piston is moved relative to the second piston at an advanced position where the second piston is prevented from protruding by the stopper mechanism. The injection molding is characterized in that the second piston is rotationally driven by the screw action of the first and second pistons, so that the two locking members are mated with each other. Machine.