JPH09109209A - Mold clamping apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold clamping apparatus which makes it possible to attempt to simplify a side cylinder type mold clamping apparatus and to effectively release a locking mechanism after molding and to strongly open the mold. SOLUTION: A movable platen 4 is telescopically moved with respect to a stationary platen 1 by a first mold switching means 5A and a second mold switching means 5B fixed to the platen 1. A clamping ram 20 having a hollow part 20a is inserted into a single-acting type clamping cylinder 18. A mechanical ram 6 is held integrally with the ram 20 by engaging the lock plate 30 of a locking mechanism 8 with the recess 7a of an engaging member 7. A distance cylinder is formed at the end of the ram 6 coupled to the platen 4, and a distance piston mounting with the member 7 is inserted. In the case of unlocking the mechanism 8, the piston 41 is driven to be extended to slightly retract the ram 20, then again driven to be retracted to slightly retract the ram 20, then again driven to be retracted to eliminate the contact surface pressure of the member 7 with the plate 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device for an injection molding machine, and more particularly, it includes a high pressure clamping means and a mold opening / closing means, and a mechanical part is formed in a hollow portion formed in a ram of the high pressure clamping means. The present invention relates to a mold clamping device provided with a lock mechanism that inserts a ram and holds the ram of a high-pressure clamping means and a mechanical ram immovably.

[0002]

2. Description of the Related Art A general injection molding machine includes a fixed platen, a movable platen disposed opposite to the fixed platen, and a mold clamping device for driving the movable platen toward and away from the fixed platen. Is equipped with.
The mold clamping device closes the molds attached to the fixed platen and movable platen respectively, presses the molds against the resin pressure injected into the cavity formed in the molds, and molds them after the molding is completed. The mold is opened by overcoming the resistance due to the adhesion of the product. The operation of the mold clamping device is performed in the order of high speed mold closing, low speed mold closing, high pressure clamping, strong mold opening, and high speed mold opening in order to shorten the molding cycle of the injection molding machine and protect the mold.

When a simple direct pressure type mold clamping device using only a clamping cylinder having a clamping pin is used as a mold clamping device of an injection molding machine, a large diameter clamping cylinder capable of high pressure clamping. Is required,
It becomes difficult to open and close the high-speed mold, the molding cycle becomes long, and a large amount of hydraulic oil is required to be supplied into the clamping cylinder. Therefore, in order to perform reliable high pressure clamping and mold opening and closing by supplying a small amount of hydraulic oil, a clamping cylinder having a clamping pin as high pressure clamping means and a mold opening and closing means connected to a movable plate are used. , A so-called mechanical hydraulic type equipped with a side cylinder, a mechanical ram that is connected to a movable plate and has its tip inserted into a clamp pingram, and a lock mechanism that unmovably integrates the mechanical ram inserted into the clamp pingram. The mold clamping device has been conventionally known (for example, see Japanese Patent Laid-Open No. 152035/55). In this mechanical hydraulic type mold clamping device, the side cylinder is driven to move the movable platen forward and backward with respect to the fixed platen, and the mechanical ram connected to the movable platen is extended by the clamp pingram and is held by the lock mechanism. Then, high pressure clamping is performed by driving the clamping pin held integrally with the mechanical ram.

In the mechanical-hydraulic mold clamping device configured as described above, the mechanical ram is held against the restraining member of the lock mechanism in order to hold the clamping pin and the mechanical ram together to perform high-pressure clamping. Since the engaging portion is pressed and the contact surface pressure is large, it becomes difficult to release the lock mechanism. Also, in the mechanical hydraulic type mold clamping device, the mold is opened by overcoming the resistance force due to the adhesion of the molded product at the initial stage of completion of molding and opening of the mold, that is, strong mold opening requiring a large mold opening force. The problem is how to do it.

As a conventional technique for releasing the lock mechanism, as disclosed in Japanese Patent Laid-Open No. 48-39550, there is provided a spring for urging the clamping pin so as to retract the mechanical mechanism. It is known that when the restraint member engaged with the ram is retracted to release the lock mechanism, the contact surface pressure of the mechanical ram with respect to the restraint member is eliminated to smoothly move the restraint member.

Furthermore, as another conventional technique for enabling the lock mechanism to be released, there is Japanese Patent Laid-Open No. 55-1520.
As disclosed in Japanese Patent Laid-Open No. 35-35, a locking cylinder is provided between a clamping cylinder and a movable plate so as to be movable along a tie bar, and a positioning cylinder for positioning the locking plate with respect to the clamping cylinder is provided. It is known that a spring is provided which acts so as to widen the gap between the clamp pingram and a lock disc supporting a rotary disc as an engaging member. When the mold is opened, the lock disk is moved so as to approach the clamp pingram by driving the positioning cylinder so that the tip of the mechanical ram is not in contact with the engaging member. Further, the reaction force of the spring causes the clamp pingram and the turntable to be separated from each other, so that the end face of the turntable is not damaged even when the turntable is rotated.

On the other hand, in order to perform strong mold opening in a mechanical hydraulic type mold clamping device, generally, Japanese Patent Publication No. 48-17130.
As disclosed in the publication, if a mold opening / closing cylinder is provided in the direction of pulling the movable plate from the fixed plate side, it is possible to satisfy both the mold opening force and the mold opening speed. Since there is a limit to the discharge amount of the pump that is the hydraulic pressure supply source in the molding machine, some measures must be taken. As disclosed in Japanese Unexamined Patent Publication No. 48-39550, it is known to provide a releasing hydraulic cylinder that performs a releasing operation in addition to a side cylinder that drives a movable plate to open and close at high speed. The mold release hydraulic cylinder has a much larger pressure receiving area than the side cylinder, and is fixedly mounted on the movable platen. The piston rod of the releasing hydraulic cylinder is connected to the piston of the side cylinder fixed to the pressure receiving plate so as to face each other.

Further, as another example for performing the conventional strong type opening, Japanese Utility Model Publication No. 50-39468 and Japanese Patent Publication No.
As disclosed in Japanese Patent Laid-Open No. 33474/1993, there is also known one in which a cylinder for performing a strong die opening is provided on the surface of the fixed plate facing the movable plate.

[0009]

The conventional technique for releasing the above-mentioned conventional lock mechanism has a problem that the structure is complicated. Moreover, the above-mentioned Japanese Patent Laid-Open No. 48-395.
The mold clamping device disclosed in Japanese Patent No. 50 is configured to supply pressure oil to the cylinder chamber on the piston rod side when performing strong mold opening. Therefore, there is a problem that the mold opening cylinder needs to be set large so that the driving force of the mold opening cylinder can be strongly opened. Furthermore, in Japanese Unexamined Patent Publication No. 48-39550, since the piston rods of the hydraulic cylinder for mold release are connected to the pistons of the side cylinders fixed to the pressure receiving plate so as to face each other, the separation is prevented. There is a problem that the arrangement of the die hydraulic cylinder and the side cylinder is limited, and the control of both cylinders becomes complicated.

The present invention has been made in view of the above problems, and a first object thereof is to simplify a mechanical-hydraulic mold clamping device and to reliably release a lock mechanism after molding and to strengthen the lock mechanism. It is to provide a mold clamping device that can perform mold opening.

A second object of the present invention is to provide a low-cost mold clamping device capable of supporting a mechanical ram with a simple structure when the mechanical ram is long.

Further, a third object of the present invention is to drive the other of the first and second mold opening / closing means provided so as to face each other with the movable plate sandwiched therebetween. It is an object of the present invention to provide a mold clamping device that can be stably driven without the mold opening / closing means becoming a resistance.

[0013]

In order to achieve the above object, a mold clamping device according to a first aspect of the present invention is a single-acting type liquid having rams arranged facing each other on a fixed plate and having a hollow portion formed therein. Pressure type high pressure clamping means, a movable plate movably arranged between the fixed plate and the high pressure clamping device, and a first hydraulic type fixed to the fixed plate to move the movable plate forward and backward with respect to the fixed plate. The mold opening / closing means, the second hydraulic die opening / closing means fixed to the high pressure clamping means for moving the movable platen forward and backward with respect to the fixed platen, and one end of the movable platen on the side facing the high pressure clamping means. A mechanical ram that is connected and has the other end inserted into the hollow part of the ram of the high-pressure clamping means, and an engagement member provided at the other end of the mechanical ram,
It is characterized in that it is provided with a lock mechanism for engaging with the engaging member so as to hold the ram of the high-pressure clamping means and the mechanical ram immovably, and a drive means for driving the engaging member forward and backward. .

A mold clamping apparatus according to a second aspect of the present invention is characterized in that, in the mold clamping apparatus according to the first aspect of the present invention, a support roller for supporting a lower portion of the mechanical ram is provided on the ram of the high pressure clamping means. To do.

A mold clamping device according to a third aspect of the present invention is the mold clamping device according to any one of the first and second aspects of the present invention, wherein either the first hydraulic type mold opening / closing means or the second hydraulic type mold opening / closing means is used. When only one of them is driven, the piston rod side cylinder chamber and the anti-cylinder chamber can communicate with each other.

In the case of molding, high-speed mold closing is performed by extension driving of the second mold opening / closing means, and the driving speed of the second mold opening / closing means is decelerated before the molds come into contact with each other to gently close the mold. At this time, the piston rod side cylinder chamber and the counter cylinder chamber of the first and second mold opening / closing means are respectively communicated with each other to form a differential circuit. Since the hydraulic fluid is supplied from the anti-piston rod side cylinder chamber to the piston rod side cylinder chamber of the first type opening / closing unit which is driven and retracted, it is not sucked and becomes a resistance for extension drive of the second type opening / closing unit. There is no. Then, the ram of the high-pressure clamping means and the mechanical ram are integrally engaged with each other by the lock mechanism, and the injection molding is performed while the high-pressure clamping means is driven. Due to the high-pressure clamping, the lock mechanism and the engaging member press each other to increase the contact surface pressure.

After the completion of molding, the high-pressure clamping is stopped, and the engaging member is driven by the driving means so as to be separated from the mechanical ram. By driving the engaging members away from each other, the ram of the high-pressure clamping means retracts. Then, when the engaging member is driven by the drive means so as to be in close contact with the mechanical ram, the lock mechanism and the engaging member are separated from each other, the contact surface pressure is eliminated, and the lock mechanism can be easily released. Further, since the single-acting high-pressure clamping means can be adopted, the structure including the circuit connected thereto can be simplified.

After that, the first mold opening / closing means is driven to extend and the second mold opening / closing means is driven to retract, thereby performing strong mold opening. Since the first mold opening / closing means is fixedly installed on the fixed platen, the driving force in the extending direction is large. In addition to the first type opening / closing means, the second type
Since the mold opening / closing means is fixed, the strong mold opening can be surely performed by the first and second mold opening / closing means. After the mold is opened, the piston rod side cylinder chambers of the first and second mold opening / closing means and the anti-cylinder chamber are respectively communicated with each other to form a differential circuit, and the first mold opening / closing means is opened. High speed mold opening is performed by the extension drive of. Since the hydraulic fluid is supplied from the anti-piston rod side cylinder chamber to the piston rod side cylinder chamber of the second type opening / closing unit which is driven and retracted, it is not sucked and becomes a resistance for extension drive of the first type opening / closing unit. There is no.

When the mechanical ram is lengthened to lengthen the stroke, it is possible to support the mechanical ram from below by providing a support roller on the ram of the high-pressure clamping means. The support of the mechanical ram is such that the support roller rolls below the mechanical ram when the mechanical ram extends with respect to the clamping pin. Therefore, it is not necessary to finish the surface of the mechanical ram to be smooth.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a mold clamping device according to the present invention will be described below with reference to FIGS. 1 and 2. The same reference numerals in the drawings denote the same or corresponding parts.

The mold clamping device according to the present invention is generally described as a fixed plate 1
And a single-acting hydraulic high-pressure clamping means 2 having a ram 20 having a hollow portion 20a formed opposite to the stationary platen 1
And a tie bar 3 provided between the fixed platen 1 and the high-pressure clamping means, and a movable platen 4 movably inserted into the tie bar 3.
And the movable platen 4 is fixed to the fixed platen 1 to move the movable platen 4 forward and backward with respect to the fixed platen 1, and the high pressure clamping means 2 is fixed to the movable platen 4 to be fixed. Second hydraulic die opening / closing means 5B for moving back and forth with respect to the movable platen 4, one end of which is connected to the surface of the movable plate 4 facing the high pressure clamping means 2, and the other end is hollow of the ram 20 of the high pressure clamping means 2. The mechanical ram 6 inserted through the portion 20a, the engagement member 7 provided at the other end of the mechanical 6, and the ram 20 of the high-pressure clamping means 2 and the mechanical ram 6 are engaged so as to hold them immovably. A lock mechanism 8 that engages the member 7, and a drive means that drives the engagement member 7 forward and backward in the longitudinal direction of the ram 20 of the high-pressure clamping means 2 and the mechanical ram 6.
It is equipped with 9 and. Then, molds 10 and 11 are attached to the surfaces of the fixed plate 1 and the movable plate 4 that face each other, respectively.

The stationary platen 1 is formed in a substantially rectangular shape. A tapered hole 14 into which a nozzle (not shown) of a heating cylinder is inserted is formed in the center, and each corner has four corners. One end of each tie bar 3 of the book is connected by a nut 15.

The high pressure clamping means 2 is a clamping cylinder.
Clamping gram through seal member 19 at the tip opening of 18
It is a single-acting type in which a hydraulic pressure source having a surge tank 21 at the rear end is connected, with 20 inserted. Further, the cylinder chamber 18a of the clamping cylinder 18 is provided with a pressure sensor or a timer (not shown) having upper and lower limit contacts for confirming that the pressure in the cylinder chamber 18a has been released after the completion of molding. ing. The clamping cylinder 18 and the clamping pin 20 have the first and second
Mold 1 with a larger diameter than the mold opening / closing means 5A and 5B
It is set to a stroke of a length that can be adjusted according to the mold thickness of 0 and 11. And the clamping cylinder 18 is
The other end of the tie bar 3 connected to the fixed plate 1 is connected by a nut (not shown). The cramping gram 20 has a hollow portion 20a having an opening at its tip.

The movable platen 4 is formed in a substantially rectangular shape so as to be aligned with the fixed platen 1, and tie bars 3 are inserted at each corner so that the movable platen 4 can move back and forth with respect to the fixed platen 1.

The first and second mold opening / closing means 5A, 5B have a diameter smaller than that of the high-pressure clamping means 2 and are set to have a stroke long enough to open / close the mold.
And 27 and piston rods 26 and 28 which are respectively inserted through these side cylinders 25 and 27. The side cylinder 25 is fixed to the fixed platen 1, and the tip of the piston rod 26 is connected to the movable platen 4. The side cylinder 27 is fixed to the clamping cylinder 18, and the tip of the piston rod 28 is connected to the movable platen 4. Side cylinders 25 and 27 have tips (anti-piston rod side cylinder chamber) and rear ends (piston rod side cylinder chamber)
A hydraulic pressure source common to the clamping cylinder 18 or different from the hydraulic pressure source is connected to and. The front end and the rear end of the first and second mold opening / closing means 5A and 5B can communicate with each other so as to form a differential circuit (see FIG. 9).

One end of the mechanical ram 6 is connected to the surface of the movable platen 4 facing the clamping cylinder 18, and the other end of the mechanical ram 6 has a clearance with respect to the tip opening of the clamping pin 20 in the hollow portion 20a. It has been inserted.

As shown in FIGS. 1 and 2, the engaging member 7
In the case of this embodiment, an annular recess 7a is formed. On the other hand, the lock mechanism 8 is the recess of the engaging member 7.
State with clearance α for 7a ((a) of FIG. 4)
Refer to).) A pair of lock plates 30 that can be entered
And a lock cylinder 31 for moving the lock plate 30 forward and backward with respect to the recess 7a of the engaging member 7. As shown in FIG. 2, a space plate 33 and a top plate 34 having an insertion portion 32 that is movably inserted into the tie bar 3 located in the space are provided at the tip of the cramping gram 20 so that the lock plate 30 is sandwiched. Installed. It should be noted that the lock mechanism 8 may be provided so as to engage the engaging member 7 in the vertical direction as shown in FIG. 1 or may be provided in the lateral direction as shown in FIG. But it's okay. In FIG. 2, the right half shows an unlocked state in which the lock plate 30 is retracted from the recess 7a of the engaging member 7, and the left half shows the recess 7a of the engaging member 7.
The lock state in which the lock plate 30 is engaged is shown in FIG.

With respect to the lock mechanism 8, it is detected that the recess 7a of the engaging member 7 is close to the engaging position with the lock plate 30 by driving the first and second mold opening / closing means 5A, 5B. Limit switch or encoder (hereinafter referred to as low speed position setting LS) as detecting means in order to set the position where the driving speed of the first and second mold opening / closing means 5A, 5B is decelerated.
Is provided (not shown). Further, as shown in FIG. 4A, it is detected that the concave portion 7a of the engaging member 7 is at the longitudinal position with a slight gap α between the concave portion 7a and the lock plate 30, and the lock cylinder 31 is locked. The lock plate 30 is extended to drive the lock plate 30 into the recess 7a of the engaging member 7.
Limit switch or encoder (hereinafter, referred to as engagement member position detection LS) as the detection means for engaging with
Are provided (not shown).

Driving means 9 for driving the engaging member 7 forward and backward in the longitudinal direction of the clamp pingram 20 and the mechanical ram 6.
Is configured such that a distance cylinder 40 is formed on the other end side of the mechanical ram 6 which is inserted into the clamping pin 20 and a distance piston 41 having an engaging member 7 attached to the tip thereof is inserted into the distance cylinder 40. is there.
The circuit connected to the distance cylinder 40 is not shown.

The mechanical ram 6 of the mold clamping device according to the present invention constructed as described above is cantilevered with respect to the movable platen 4 and has a slight clearance between the mechanical ram 6 and the tip opening of the clamping pin 20. When the mechanical ram 6 is long, the support roller 44 for supporting the mechanical ram 6 from below is provided on the surface of the movable plate side 4 of the top plate 34, as shown in FIGS. 5 and 6. Can be provided.

Further, the engaging member 7 of the mold clamping device according to the present invention
The lock mechanism 8 is not limited to the above-described configuration, and as shown in FIGS. 7 and 8, an annular groove 7b is formed in multiple lines around the entire circumference of the engaging member 7, and the lock plate 30 is provided. Instead of the ridge 50b, which engages with the groove 7b of the engaging member 7.
It is also possible to form the chuck member 50 in the form of a pair of half nuts, which are formed on the inner peripheral surface and surround the entire circumference of the engaging member 7. In this case, the groove 7b of the engaging member 7 is formed so that the side wall 7c on the side of the clamping cylinder 18 is orthogonal to the axial direction and the side wall 7d on the side of the movable plate 4 is inclined with respect to the axial direction. And chuck members
It is preferable that the protrusion 50b of the 50 is such that the side wall 50c on the top plate 34 side is orthogonal to the axial direction and the side wall 50d on the space plate 33 side is inclined with respect to the axial direction. Also in this case, similarly to the above-described embodiment, the space α shown in (a) of FIG. 8 and the side wall 7c on the movable plate side orthogonal to the axial direction of the groove 7b of the engaging member 7, It is formed between the protrusion 50b of the chuck member 50 and the side wall 50c on the top plate side orthogonal to the axial direction.

The mold is driven by driving the second mold opening / closing means 5B.
Limit switches and encoders (hereinafter referred to as mold closing completion position setting LS) are respectively provided as means for confirming that 10 and 11 are in contact and detecting completion of mold closing (not shown). . Further, as a means for detecting that the molds 10 and 11 have been opened by overcoming the adhesive force of the molded product and starting the high speed mold opening, a limit switch or an encoder (hereinafter referred to as a high speed mold opening initial position setting LS Is provided (not shown).

Next, the operation of the mold clamping device according to the present invention will be described with reference to FIGS. 1, 3 and 4. In addition, in this description, when the thickness of the molds 10 and 11 attached to the fixed platen 1 and the movable platen 4 is the maximum, that is, as shown in FIG. Will be explained depending on the case.

From the state shown in FIG. 1, high-speed mold closing is performed by driving the second mold opening / closing means 5B to extend. The low speed position setting LS detects that the recess 7a of the engaging member 7 is close to the engaging position with the lock plate 30, and the second position is set before the molds 10 and 11 come into contact with each other.
The drive speed of the mold opening / closing means 5B is reduced to gently close the molds 10 and 11 (FIG. 3). When it is detected by the mold closing completion position setting LS that the molds are in close contact with each other, the engagement member position detection LS causes the recess 7a of the engagement member 7 to be in contact with the lock plate 30, as shown in (a) of FIG. After detecting that there is a gap α between them, the lock cylinder 31 is driven to extend and the lock plate 30 enters the recess 7a of the engaging member 7.

When the mold closing is completed and the clamping mechanism 20 holds the clamping pin 20 and the mechanical ram 6 together, the cylinder chamber 18a of the clamping cylinder 18 and the piston rod 28 of the side cylinder 27 on the opposite side. The pressure oil is supplied to the cylinder chamber of the side cylinder 25 and the cylinder chamber of the side cylinder 25 on the piston rod 26 side to perform high pressure clamping. When it detects that the upper limit contact of the pressure sensor of the clamping cylinder 18 has reached a predetermined pressure during this boosting, injection is started, molten resin is supplied to the cavities 10 and 11 in the mold, and injection molding is performed. .

While the high-pressure clamping is being performed, the pressing force due to the extension of the clamp pingram 20 is transmitted to the engaging member 7 through the space plate 33 and the lock plate 30, so that (b) in FIG. As shown in (), the lock plate 30 of the lock mechanism 8 and the engaging member 7 are pressed against each other, so that the contact surface pressure of both 30 and 7 is high. Therefore, when the molding is completed and the mold is opened, the supply of the pressure oil to the clamping cylinder 18 is stopped and the lower limit contact of the pressure sensor 19 or the timer is used for the cylinder chamber 18a.
After confirming that the internal pressure has been released to the specified pressure,
As shown in FIG. 4 (c), pressure oil is supplied to the cylinder chamber 40a on the right side of the distance cylinder 40 in the figure, and the distance piston 41 is extended and driven to separate the engaging member 7 from the mechanical ram 6 by a distance α. Let

The engaging member 7 is separated from the mechanical ram 6 by a distance α
By only separating them, the cramping gram 20 moves so as to retract. Then, when pressure oil is supplied to the cylinder chamber 40b on the left side of the distance cylinder 40 in the drawing to bring the engagement member 7 into close contact with the mechanical ram 6, FIG.
Similar to the state shown in Fig. 5, a gap α is formed between the engaging member 7 and the lock plate 30 of the lock mechanism 8, the contact surface pressure between the two 7 and 30 disappears, and the lock cylinder 31 is retracted to cause the lock plate 30 to retract. It is possible to retract the 30 from the recess 7a of the engaging member 7, that is, to release the lock mechanism 8.

After that, the first die opening / closing means 5A is driven to extend and the second die opening / closing means 5B is driven to retract, thereby performing a strong die opening. Since the side cylinder 25 is fixed to the fixed board 1,
The extension drive of the mold opening / closing means 5A is performed by supplying pressure oil to the cylinder chamber of the side cylinder 25 opposite to the piston rod 26. Side cylinder 25 piston rod 26
Since the cylinder chamber on the opposite side has a larger pressure receiving area than the cylinder chamber on the piston rod 26 side, the driving force in the extension direction is large. Furthermore, by supplying pressure oil to the cylinder chamber on the piston rod 28 side of the side cylinder 27 fixed to the clamping cylinder 18, strong die opening can be performed, and therefore the high pressure clamping means 2 is a single acting type. can do. After confirming that the molds 10 and 11 have been strongly opened by the high-speed mold opening initial position setting LS, the first mold opening / closing means
5A is further extended and driven to perform high-speed mold opening. In addition, the clamp pingram 20 is for the mold from the minimum to the maximum mold thickness,
Although it has a stroke capable of adjusting the mold thickness, detailed description of the mold thickness adjustment is omitted.

Here, the first die opening / closing means 5A and the second die
The mutual relationship and operation of the mold opening / closing means 5B will be described in detail with reference to FIG. In FIG. 9, the mechanical ram 6, the engaging member 7, the lock mechanism 8, the driving means 9, etc.,
Some illustrations are omitted. The combination of the first die opening / closing means 5A and the second die opening / closing means 5B may be two or two depending on the machine specifications.
It is possible to make any combination such as four and four, four and four. Further, it is possible to select the mounting positions such that the mounting positions are opposed to each other by matching the mutual relationship, or the positions are shifted so as to be opposed to each other. These are extremely advantageous in selecting a position that avoids interference with an auxiliary device of the molding machine, for example, a molded product take-out device.

Next, regarding the operation, provisionally, many cylinders are mounted only on the fixed platen side, and only the powerful die opening is performed by all the cylinders. When using the cylinder of No. 2, it is necessary to suck the working oil by negative pressure in the unused cylinder when opening and closing the mold, but especially in a large molding machine with a long piping path, it is restricted by piping resistance etc. Smooth suction is not possible and operation is unstable. In order to prevent such a problem, in the present invention, the first mold opening / closing means 5A and the second mold opening / closing means 5B are opposed to each other and operated so as to completely eliminate the suction of hydraulic oil. That is, during mold closing and mold opening operations, as shown in FIGS. 9A and 9C, the first mold opening / closing means 5A and the second mold opening / closing means 5B are both on the piston rod side and on the opposite piston rod side. Put the room in communication. In the case of mold closing, by supplying hydraulic oil only to the second mold opening / closing means 5B, a differential circuit is formed to perform high-speed mold closing, and at the side of the driven first mold opening / closing means 5A. The hydraulic oil flows from the side opposite to the piston rod to the side of the piston rod, and the excess hydraulic oil returns to the tank, so that stable operation can be obtained without the need for suction. On the contrary, when the mold is opened, the same operation is performed by supplying hydraulic oil to the first mold opening / closing means 5A. Further, when the strong mold is opened, as shown in FIG. 9B, the first mold opening / closing means
Hydraulic oil is supplied to both the anti-piston rod side of 5A and the piston rod side of the second type opening / closing means 5B, and the ports on the opposite sides are opened to the tank to form a strong differential force without forming a differential circuit. become.

[0041]

According to the present invention, the single-acting hydraulic high-pressure clamping means having rams facing each other on the fixed board and having the hollow portion formed between the fixed board and the high-pressure clamping means. The movable platen movably disposed on the fixed platen, the first hydraulic die opening / closing means fixed to the fixed platen to move the movable platen forward and backward relative to the fixed platen, and the movable platen fixed to the high pressure clamping means. The second hydraulic die opening / closing means for moving back and forth with respect to the fixed board and one end thereof are connected to the surface of the movable board facing the high pressure clamping means, and the other end is inserted into the hollow portion of the ram of the high pressure clamping means. A mechanical ram, an engaging member provided at the other end of the mechanical, a locking mechanism that engages with the engaging member so as to hold the ram of the high-pressure clamping means and the mechanical ram immovable, By providing the driving means for driving the member forward and backward, in the mechanical hydraulic type mold clamping device, There is ensured a reduction, it can be canceled and strong die opening of the locking mechanism after reliably formed.

When a support roller for supporting the mechanical ram from below is provided on the movable side surface of the top plate, it is not necessary to precisely finish the surface on which the support roller of the mechanical ram rolls. The cost can be reduced.

When only one of the first hydraulic type mold opening / closing means and the second hydraulic type mold opening / closing means is driven and the respective piston rod side cylinder chambers and anti-cylinder chambers can be communicated with each other, The other mold opening / closing means, which is driven by the formation of the differential circuit, does not become a resistance, and one mold opening / closing means can be stably driven.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a mold clamping device according to the present invention.

FIG. 2 is an explanatory view showing the operation of the lock device.

FIG. 3 is a partial cross-sectional view showing a mold closed state.

FIG. 4 is a schematic diagram of the embodiment shown in FIGS.
(A) From the state where the engaging member and the cramping gram are integrally held by the lock mechanism, (b) The lock plate and the engaging member are pressed against each other when the cramping gram is extended and driven for high pressure clamping. It is explanatory drawing which shows a state and the state which extendedly driven the (c) drive means so that an engaging member may be separated from a mechanical ram.

FIG. 5 is a partially enlarged cross-sectional view showing an embodiment of a mold clamping device in the case where a support roller that supports the mechanical ram from below is provided.

FIG. 6 is a front view of the top rate of the mold clamping device shown in FIG.

FIG. 7 is a partial enlarged cross-sectional view showing another embodiment of the engagement member and the lock mechanism.

FIG. 8 is a diagram showing the embodiment shown in FIG. 7, in which (a) the locking member integrally holds the clamping member and the clamping pingram, and (b) the clamping pingram is driven to extend and high-pressure clamped. It is an explanatory view showing a state in which the lock plate and the engaging member are pressed against each other and a state in which the engaging member is extended and driven so as to be separated from the mechanical ram by the drive means (c).

FIG. 9 (a) of the first die opening / closing means and the second die opening / closing means.
It is explanatory drawing which showed the state of mold closing (b) strong mold opening (c) mold opening.

[Explanation of symbols]

 1 Fixed plate 2 High pressure clamping means 3 Tie bar 4 Movable plate 5A 1st type opening / closing means 5B 2nd type opening / closing means 6 Mechanical ram 7 Engaging member 8 Lock mechanism 9 Drive means 10, 11 Mold 20 Clamping gram 44 Support roller

Claims (3)

[Claims] 1. A single-acting hydraulic high-pressure clamping means having rams facing each other on a fixed plate and having a hollow portion formed therein, and movably arranged between the fixed plate and the high-pressure clamping means. A movable plate, a first hydraulic die opening / closing means fixed to the fixed plate to move the movable plate forward and backward with respect to the fixed plate, and a movable plate fixed to the high pressure clamping means to move the movable plate forward and backward with respect to the fixed plate. The second hydraulic die opening / closing means, the mechanical ram having one end connected to the surface of the movable plate opposite to the high pressure clamping means and the other end inserted into the hollow portion of the ram of the high pressure clamping means, and the mechanical ram. An engaging member provided at the other end, a locking mechanism that engages with the engaging member so as to hold the ram and the mechanical ram of the high-pressure clamping means immovably, and a driving means that drives the engaging member forward and backward. A mold clamping device comprising: 2. The mold clamping device according to claim 1, wherein a support roller for supporting the lower side of the mechanical ram is provided on the ram of the high-pressure clamping means. 3. The piston rod side cylinder chamber and the anti-cylinder chamber can be communicated with each other when only one of the first hydraulic die opening / closing means and the second hydraulic die opening / closing means is driven. The mold clamping device according to claim 1 or 2.