JP2884052B2 - Mold clamping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping apparatus for an injection molding machine, and more particularly to a mold clamping apparatus and a mold opening / closing means. The present invention relates to a mold clamping device provided with a lock mechanism that penetrates a ram and immovably holds a ram of a high-pressure clamping unit and a mechanical ram.

[0002]

2. Description of the Related Art A general injection molding machine includes a fixed plate, a movable plate disposed opposite to the fixed plate, and a mold clamping device for driving the movable plate close to and away from the fixed plate. It has.
The mold clamping device closes the mold attached to each of the fixed platen and the movable platen, and presses the mold with high pressure against the resin pressure injected into the cavity formed in the mold. The mold is opened by overcoming the resistance caused by 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 pressing, strong mold opening, and high-speed mold opening in order to shorten the molding cycle of the injection molding machine and protect the mold.

[0003] When a simple direct pressure type clamping device using only a clamping cylinder having a clamping gram is used as a clamping device of an injection molding machine, a large diameter clamping cylinder capable of high pressure clamping. Is required,
It is difficult to open and close the high-speed mold, and the molding cycle is lengthened, 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 opening and closing of the mold by supplying a small amount of hydraulic oil, a clamping cylinder having a clamp pingram as high-pressure clamping means and a mold opening / closing means connected to a movable platen are used. A so-called mechanical hydraulic system having a side cylinder, a mechanical ram connected to a movable platen and having a tip inserted into a clamping gram, and a lock mechanism for immovably integrating the mechanical ram inserted into the clamping gram. Is conventionally known (see, for example, Japanese Patent Application Laid-Open No. 55-152035). In this mechanical hydraulic type mold clamping device, the movable plate is moved forward and backward with respect to the fixed plate by driving the side cylinder, and the state where the mechanical ram connected to the movable plate is extended with respect to the clamp gram is held by the lock mechanism. Then, high-pressure pressing is performed by driving the clamp gram held integrally with the mechanical ram.

[0004] In the mechanical hydraulic type clamping device constructed as described above, the clamping ram and the mechanical ram are integrally held and high-pressure clamping is performed. Is pressed, so that the contact surface pressure is large, and it is difficult to release the lock mechanism. Further, 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 in the initial stage of the mold opening after the molding is completed, that is, a strong mold opening requiring a large mold opening force. The question is how to do it.

As a conventional technique for releasing the lock mechanism, as disclosed in Japanese Patent Laid-Open Publication No. 48-39550, a mechanical spring is provided to bias the clamp gram backward. There is known a configuration in which, when the lock member is released by retracting the restraint member engaged with the ram, the contact surface pressure of the mechanical ram against the restraint member is eliminated and the restraint member is smoothly moved.

Another prior art for enabling the lock mechanism to be released is disclosed in Japanese Patent Application Laid-Open No. 55-1520.
As disclosed in Japanese Patent No. 35, a locking cylinder is provided between a clamping cylinder and a movable board so as to be movable along a tie bar, and a positioning cylinder for positioning the locking board with respect to the clamping cylinder is provided. Further, there is known an apparatus provided with a spring which acts to widen a gap between a clamp gram and a lock plate which supports a rotary plate as an engagement member. When the mold is opened, the lock plate is moved so as to approach the clamp gram by driving the positioning cylinder, so that the tip of the mechanical ram is not in contact with the engaging member. In addition, the clamping force and the rotating disk are separated from each other by the reaction force of the spring, and even if the rotating disk is rotated, the end surface of the rotating disk is not damaged.

On the other hand, in order to open a powerful mold in a mechanical hydraulic type mold clamping apparatus, generally, Japanese Patent Publication No. 48-17130 is used.
As disclosed in Japanese Unexamined Patent Publication, if a mold opening / closing cylinder is provided in a direction in which the movable board is pulled from the fixed board side, it is possible to satisfy both the mold opening force and the mold opening speed. In a molding machine, there is a limit to the discharge amount of a pump serving as a hydraulic pressure source, so that some measures are required. As disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 48-39550, it is known to provide a releasing hydraulic cylinder for performing a releasing operation in addition to a side cylinder for driving a movable platen to open and close at a high speed. The release hydraulic cylinder has a much larger pressure receiving area than the side cylinder, and is fixed to the movable platen. The piston rod of the release hydraulic cylinder is connected to a piston of a side cylinder fixed to the pressure receiving plate so as to face the piston rod.

Further, as another example for performing the conventional strong mold opening, Japanese Utility Model Laid-Open Publication No. Sho.
As disclosed in JP-A-33474, there is also known a fixed plate provided with a cylinder for performing a strong mold opening on a surface facing a movable plate.

[0009]

The prior art for enabling the above-mentioned conventional lock mechanism to be released has a problem that the structure is complicated. Further, Japanese Patent Application Laid-Open No.
In the mold clamping device disclosed in Japanese Patent Publication No. 50, pressure oil is supplied to the cylinder chamber on the piston rod side when the strong mold is opened. 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 Patent Application Laid-Open No. 48-39550, since 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, There is a problem that the arrangement of the mold hydraulic cylinder and the side cylinder is limited, and that the control of both cylinders is complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a first object of the present invention is to provide a mechanical-hydraulic type mold clamping device which simplifies the operation, reliably releases the locking mechanism after molding, and increases the strength. An object of the present invention is to provide a mold clamping device capable of opening a mold.

It is a second object of the present invention to provide a low-cost mold clamping device that can support a mechanical ram with a simple structure when the mechanical ram is long.

Further, a third object of the present invention is to drive one of the first and second mold opening / closing means provided so as to face each other with a movable plate interposed therebetween, and to follow the other. An object of the present invention is to provide a mold clamping device that can stably drive the mold opening and closing means without causing any resistance.

[0013]

According to a first aspect of the present invention, there is provided a mold clamping apparatus comprising a ram having a hollow portion and a ram disposed opposite to a fixed plate. Pressure type high-pressure pressing means, a movable plate movably disposed between the fixed plate and the high-pressure pressing means, and a first hydraulic type fixed to the fixed plate and moving the movable plate forward and backward with respect to the fixed plate. Mold opening / closing means, second hydraulic mold opening / closing means fixed to the high-pressure pressing means for moving the movable plate toward and away from the fixed plate, and one end of a surface of the movable plate facing the high-pressure pressing means. A mechanical ram that is connected and the other end of which is inserted into the hollow portion of the ram of the high-pressure pressing means, and an engaging member provided at the other end of the mechanical ram,
A lock mechanism for engaging the engaging member so as to immovably hold the ram of the high-pressure pressing means and the mechanical ram, and a driving means for driving the engaging member forward and backward. .

According to a second aspect of the present invention, there is provided a mold clamping apparatus according to the first aspect, wherein a support roller for supporting a lower portion of the mechanical ram is provided on the ram of the high-pressure pressing means. Is what you do.

According to a third aspect of the present invention, there is provided a mold clamping apparatus according to any one of the first and second aspects, wherein the first hydraulic type opening / closing means and the second hydraulic type opening / closing means are provided. When only one of them is driven, each piston rod side cylinder chamber and the opposite cylinder chamber can be communicated 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 reduced before the molds come into contact with each other, so that the mold is gently closed. At this time, the piston rod side cylinder chamber of the first and second mold opening / closing means communicates with the opposite cylinder chamber to form a differential circuit. The hydraulic fluid is supplied to the piston rod-side cylinder chamber of the first mold opening / closing means that is driven and retracted, so that the hydraulic fluid is supplied from the anti-piston rod-side cylinder chamber. There is no. Then, the ram of the high-pressure pressing means and the mechanical ram are integrally engaged by the lock mechanism, and injection molding is performed with the high-pressure pressing means driven. Due to the high-pressure pressing, the lock mechanism and the engagement member press against each other to increase the contact surface pressure.

After the molding is completed, the high-pressure pressing is stopped, and the engaging member is driven by the driving means so as to be separated from the mechanical ram. The ram of the high-pressure pressing means is retracted by the separation driving of the engaging member. When the engagement member is driven by the driving means so as to be in close contact with the mechanical ram, the lock mechanism and the engagement member are separated from each other, the contact surface pressure is eliminated, and the lock mechanism can be easily released. In addition, since a single-action type high-pressure pressurizing means can be adopted, the structure including the circuit connected thereto can be simplified.

Thereafter, the first mold opening / closing means is extended and driven, and the second mold opening / closing means is retracted to perform strong mold opening. Since the first mold opening / closing means is fixed to the fixed board, the driving force in the extension direction is large. Also, in addition to the first mold opening and closing means,
Since the mold opening / closing means is fixed, the strong mold opening can be reliably performed by the first and second mold opening / closing means. After the mold is opened, a differential circuit is formed by connecting the piston rod side cylinder chamber and the counter cylinder chamber of the first and second mold opening / closing means in the same manner as in closing the mold, thereby forming the first mold opening / closing means. High-speed mold opening is performed by the extension drive of. Hydraulic fluid is supplied from the anti-piston rod side cylinder chamber to the piston rod side cylinder chamber of the second mold opening / closing means that is driven and retracted, so that there is no suction, thus providing resistance to extension drive of the first mold opening / closing means. There is no.

When the mechanical ram is lengthened in order to lengthen the stroke, the mechanical ram can be supported from below by providing a support roller on the ram of the high-pressure pressing means. In the support of the mechanical ram, when the mechanical ram extends with respect to the clamping gram, the support roller rolls below the mechanical ram. Therefore, it is not necessary to finish the surface of the mechanical ram smoothly.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mold clamping device according to the present invention will be described below with reference to FIGS. The same reference numerals in the drawings denote the same or corresponding parts.

The mold clamping device according to the present invention generally comprises a fixed platen 1
And a single-acting hydraulic high-pressure pressing means 2 having a ram 20 with a hollow portion 20a formed opposite to the fixed platen 1.
And a tie bar 3 provided between the fixed plate 1 and the high-pressure pressing means, and a movable plate 4 movably inserted through the tie bar 3.
A first hydraulic mold opening / closing means 5A fixed to the fixed platen 1 to move the movable platen 4 forward and backward with respect to the fixed platen 1, and a movable platen 4 fixed to the high-pressure pressing means 2 One end is connected to the surface of the movable platen 4 facing the high-pressure pressurizing means 2 and the other end is connected to the hollow of the ram 20 of the high-pressure pressurizing means 2. The mechanical ram 6 inserted into the portion 20a, the engaging member 7 provided at the other end of the mechanical 6, and the ram 20 of the high-pressure pressing means 2 and the mechanical ram 6 are engaged so as to be immovable. A lock mechanism 8 for engaging the member 7 and a driving means for driving the engaging member 7 to advance and retreat in the longitudinal direction of the ram 20 and the mechanical ram 6 of the high-pressure pressing means 2
9 is provided. Then, dies 10 and 11 are attached to the opposing surfaces of the fixed platen 1 and the movable platen 4, respectively.

The fixed platen 1 is formed in a substantially square shape. A tapered hole 14 into which a nozzle (not shown) of a heating cylinder is inserted is formed at the center, and 4 holes are formed at each corner. One end of each tie bar 3 is connected by a nut 15.

The high-pressure pressing means 2 is a clamping cylinder.
Clampgram via seal member 19 at the tip opening of 18
20 is a single-acting type in which a hydraulic source having a surge tank 21 at the rear end is connected. The cylinder chamber 18a of the clamping cylinder 18 is provided with a pressure sensor or a timer (not shown) having upper and lower contacts for confirming that the pressure in the cylinder chamber 18a has been released after the molding is completed. ing. Clamping cylinder 18 and clamping gram 20 are divided into first and second
Mold 1 that can be installed with a larger diameter than mold opening / closing means 5A, 5B
The stroke is set to a length that can be adjusted according to the mold thickness of 0 and 11. And the clamping cylinder 18
The other end of the tie bar 3 connected to the fixed platen 1 is connected by a nut (not shown). The clamp gram 20 has a hollow portion 20a having an opening at the 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 into each corner so as to be able to move forward and backward with respect to the fixed platen 1.

The first and second mold opening / closing means 5A and 5B are smaller in diameter than the high-pressure pressing means 2 and have a stroke length sufficient for opening and closing the mold.
And 27, and piston rods 26 and 28 inserted into these side cylinders 25 and 27, respectively. The side cylinder 25 is fixed to the fixed board 1, and the tip of the piston rod 26 is connected to the movable board 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. The front end of the side cylinders 25 and 27 (anti-piston rod side cylinder chamber) and the rear end (piston rod side cylinder chamber)
, A hydraulic source common to the clamping cylinder 18 or another hydraulic source is connected. The front and rear ends of the first and second mold opening / closing means 5A and 5B can communicate with each other so that a differential circuit can be formed (see FIG. 9).

The mechanical ram 6 has one end connected to the surface of the movable platen 4 on the side facing the clamping cylinder 18 and the other end having a clearance with respect to the tip opening of the clamping pingram 20 in the hollow portion 20a. It has been inserted.

As shown in FIG. 1 and FIG.
In this embodiment, an annular concave portion 7a is formed. On the other hand, the lock mechanism 8 is
7a with clearance α (FIG. 4 (a)
) And a pair of lock plates 30
And a lock cylinder 31 that moves the lock plate 30 forward and backward with respect to the concave portion 7a of the engagement member 7, respectively. At the tip of the clamping gram 20, as shown in FIG. 2, a space plate 33 and a top plate 34 having an insertion portion 32 that is movably inserted into a tie bar 3 located in the gap are sandwiched by the lock plate 30. Installed. The locking mechanism 8 may be provided so as to engage the engaging member 7 from the up and down direction as shown in FIG. 1 or to be engaged from the left and right direction as shown in FIG. May be. 2, the right half shows an unlocked state in which the lock plate 30 is retracted from the concave portion 7a of the engaging member 7, and the left half shows the concave portion 7a of the engaging member 7.
2 shows a locked state in which the lock plate 30 is engaged.

In connection with the lock mechanism 8, it is detected that the concave portion 7a of the engagement member 7 has approached the engagement position with the lock plate 30 by driving the first and second mold opening / closing means 5A, 5B. In order to set the position at which the driving speed of the first and second mold opening / closing means 5A, 5B is reduced, a limit switch or an encoder (hereinafter referred to as a low speed position setting LS) is used as a detecting means.
(Not shown). Further, as shown in FIG. 4 (a), 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 lock member 30 and the lock cylinder 31 is moved. The locking plate 30 is extended to drive the locking member 30 into the concave portion 7a of the engagement member 7.
, A limit switch or an encoder (hereinafter referred to as an engagement member position detection LS) as a detection means.
(Not shown).

Driving means 9 for driving the engaging member 7 forward and backward in the longitudinal direction of the clamp gram 20 and the mechanical ram 6.
A distance cylinder 40 is formed on the other end side of the mechanical ram 6 that is inserted into the clamp pingram 20, and a distance piston 41 having an engaging member 7 attached to the tip is inserted through 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 having the above-described structure has a small clearance between the movable platen 4 and the opening of the tip of the clamp gram 20 in a cantilever state. In the case where the mechanical ram 6 is long, as shown in FIGS. 5 and 6, the support roller 44 for supporting the mechanical ram 6 from below on the surface of the movable platen 4 of the top plate 34, as shown in FIGS. 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, as shown in FIGS. Instead, the ridge 50b engaging with the groove 7b of the engagement member 7
Can be formed on the inner peripheral surface to form a pair of half nut-shaped chuck members 50 that 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 clamping cylinder 18 side is orthogonal to the axial direction and the side wall 7d on the movable platen 4 side is inclined with respect to the axial direction. And chuck member
The 50 ridges 50b desirably have the side wall 50c on the top plate 34 side orthogonal to the axial direction and the side wall 50d on the space plate 33 side inclined with respect to the axial direction. Also, in this case, similarly to the above-described embodiment, the interval α shown in FIG. 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 provided as means for confirming the contact of the molds 10 and 11 and detecting the completion of mold closing (not shown). . Also, as means for detecting that the molds 10 and 11 have been opened by overcoming the adhesive force of the molded product and starting high-speed mold opening, a limit switch or an encoder (hereinafter referred to as a high-speed mold opening initial position setting LS) is used. (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 this description, it is assumed that the thickness of the molds 10 and 11 attached to the fixed platen 1 and the movable platen 4 is maximum, that is, as shown in FIG. Will be described.

From the state shown in FIG. 1, high-speed mold closing is performed by extension driving of the second mold opening / closing means 5B. The low-speed position setting LS detects that the concave portion 7a of the engagement member 7 is close to the engagement position with the lock plate 30, and the second position before the molds 10 and 11 come into contact with each other.
The driving speed of the mold opening / closing means 5B is reduced, and the molds 10, 11 are gently closed (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 concave portion 7a of the engagement member 7 to contact the lock plate 30 as shown in FIG. After detecting that the lock cylinder 31 is at the position having the gap α therebetween, the lock cylinder 31 is extended and driven to cause the lock plate 30 to enter the concave portion 7a of the engagement member 7.

When the mold closing is completed and the clamping gram 20 and the mechanical ram 6 are integrally held by the lock mechanism 8, the cylinder chamber 18a of the clamping cylinder 18 and the piston rod 28 of the side cylinder 27 on the opposite side. And pressurized oil is supplied to the cylinder chamber of the side cylinder 25 and the cylinder chamber of the side cylinder 25 on the side of the piston rod 26 to perform high-pressure compression. In the course of this pressure increase, when it is detected that the upper limit contact of the pressure sensor of the clamping cylinder 18 has reached a predetermined pressure, injection is started, molten resin is supplied to the cavities of the molds 10 and 11, and injection molding is performed. .

When the high-pressure clamping is being performed, the pressing force due to the extension of the clamp gram 20 is transmitted to the engaging member 7 via the space plate 33 and the lock plate 30. ), The lock plate 30 of the lock mechanism 8 and the engagement member 7 press against each other, so that the contact surface pressure between the two 30 and 7 is high. Therefore, when molding is completed and the mold is opened, the supply of pressure oil to the clamping cylinder 18 is stopped, and the lower limit contact of the pressure sensor 19 or a timer is used to release the cylinder chamber 18a.
After confirming that the internal pressure has been released to the specified pressure,
As shown in FIG. 4C, pressure oil is supplied to the right cylinder chamber 40a in the drawing of the distance cylinder 40, and the distance piston 41 is extended to drive the engaging member 7 away from the mechanical ram 6 by a distance α. Let it.

The engaging member 7 is separated from the mechanical ram 6 by a distance α.
With only a separation, the clamping gram 20 moves to retract. When pressure oil is supplied to the left cylinder chamber 40b in the figure of the distance cylinder 40 to bring the engagement member 7 into close contact with the mechanical ram 6, FIG.
A gap α is formed between the engagement member 7 and the lock plate 30 of the lock mechanism 8 as in the state shown in FIG. It is possible to retract the 30 from the recess 7a of the engaging member 7, that is, to release the lock mechanism 8.

Thereafter, the first mold opening / closing means 5A is extended and driven, and the second mold opening / closing means 5B is retracted to perform strong mold opening. Since the side cylinder 25 is fixed to the fixed platen 1,
The extension drive of the mold opening / closing means 5A is performed by supplying pressure oil to a cylinder chamber of the side cylinder 25 opposite to the piston rod 26. Piston rod 26 of side cylinder 25
The cylinder chamber on the opposite side has a larger pressure receiving area than the cylinder chamber on the piston rod 26 side, and therefore has a larger driving force in the extension direction. Further, by supplying pressurized oil to the cylinder chamber on the side of the piston rod 28 of the side cylinder 27 fixed to the clamping cylinder 18, it is possible to open the powerful mold, so that 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
The 5A is further extended to perform high-speed mold opening. In addition, the clamping gram 20 is for the mold from the minimum to the maximum mold thickness.
Although the stroke has a mold thickness adjustable, a detailed description of the mold thickness adjustment is omitted.

Here, the first mold opening / closing means 5A and the second mold opening / closing means 5A
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 have been omitted. The combination of the first mold opening / closing means 5A and the second mold opening / closing means 5B depends on the machine specifications.
Any combination such as book, four, four and four can be used. In addition, the mounting positions can be freely selected such that they are opposed to each other by matching them with each other, or are opposed to each other with their positions shifted. This is extremely advantageous in selecting an attachment device of the molding machine, for example, a position that avoids interference with the molded product removal device.

Next, regarding the operation, suppose that a large number of cylinders are mounted only on the fixed platen side and only the strong mold opening is performed by all cylinders, and a large force is not required. When using cylinders, the unused cylinders need to suction hydraulic oil by negative pressure when opening and closing the mold. Smooth suction is not possible and operation is not stable. 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 are operated so that suction of hydraulic oil is not required at all. That is, at the time of the 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 cylinders on the piston rod side and the counter piston rod side. The room is 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 and high-speed mold closing is performed, and the driven first mold opening / closing means 5A side is provided. Hydraulic oil flows from the non-piston rod side to the piston rod side, and the excess hydraulic oil returns to the tank, so that stable operation can be obtained without requiring suction. When the mold is opened, the same operation is performed by supplying the working oil to the first mold opening / closing means 5A. When the strong mold is opened, as shown in FIG.
Hydraulic oil is supplied to both the anti-piston rod side of 5A and the piston rod side of the second mold opening / closing means 5B, and the ports on the opposite sides are released to the tank to obtain a strong force without forming a differential circuit. become.

[0041]

According to the present invention, there is provided a single-acting hydraulic high-pressure pressing means having a ram having a hollow portion disposed opposite to a fixed plate, and between the fixed plate and the high-pressure pressing means. A movable plate fixed to the fixed plate, a first hydraulic mold opening / closing means fixedly moving the movable plate with respect to the fixed plate, and a movable plate fixed to the high-pressure clamping means. A second hydraulic mold opening / closing means for moving forward / backward with respect to the fixed board, one end of which is connected to a surface of the movable board facing the high-pressure pressing means, and the other end of which is inserted into a hollow portion of a ram of the high-pressure pressing means; A mechanical ram, an engaging member provided at the other end of the mechanical, a lock mechanism engaging the engaging member so as to immovably hold the ram of the high-pressure pressing means and the mechanical ram, By providing a driving means for driving the member forward and backward, a mechanical hydraulic type mold clamping device can be simplified. 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. Costs can be reduced.

When only one of the first hydraulic type opening / closing means and the second hydraulic type opening / closing means is driven, the piston rod side cylinder chamber and the counter cylinder chamber can communicate with each other. In addition, the other mold opening / closing means, which is driven by the formation of the differential circuit, does not become a resistance, so that one mold opening / closing means can be driven stably.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing an operation of a lock device.

FIG. 3 is a partial sectional view showing a state in which a mold is closed.

FIG. 4 is a cross-sectional view of the embodiment shown in FIGS.
(A) From the state where the engaging member and the clamp gram are integrally held by the lock mechanism, (b) the lock plate and the engaging member when the clamp gram is extended and driven to perform high-pressure pressing are pressed against each other. It is explanatory drawing which shows a state and (c) the state which extended and driven so that an engaging member might separate from a mechanical ram by the drive means.

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

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

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

FIG. 8 shows the embodiment shown in FIG. 7, in which (a) the engaging member and the clamp gram are integrally held by the lock mechanism, and (b) the clamp gram is extended and driven to perform high-pressure pressing. It is an explanatory view showing a state where the lock plate and the engaging member are pressed against each other and a state where the engaging member is extended and driven by the driving means so as to be separated from the mechanical ram.

FIG. 9A shows the first mold opening / closing means and the second mold 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 platen 2 High pressure clamping means 3 Tie bar 4 Movable platen 5A First mold opening / closing means 5B Second mold opening / closing means 6 Mechanical ram 7 Engaging member 8 Lock mechanism 9 Driving means 10, 11 Mold 20 Clamp gram 44 Supporting roller

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-86062 (JP, A) JP-A-5-74825 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 45/64-45/68 B29C 33/20-33/24 B22D 17/26

Claims (3)

(57) [Claims] 1. A single-acting hydraulic high-pressure clamping means having a ram having a hollow portion disposed opposite to a fixed plate, and movably disposed between the fixed plate and the high-pressure clamping means. Movable plate, first hydraulic die opening / closing means fixed to the fixed plate for moving the movable plate with respect to the fixed plate, and movable plate fixed to the high-pressure clamping means for moving the movable plate with respect to the fixed plate. A second hydraulic mold opening / closing means, a mechanical ram having one end connected to the surface of the movable plate facing the high-pressure pressing means and the other end inserted into the hollow portion of the ram of the high-pressure pressing means; An engaging member provided at the other end, a lock mechanism for engaging the engaging member so as to immovably hold the ram and the mechanical ram of the high-pressure pressing means, and a driving means for driving 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 a lower portion of the mechanical ram is provided on the ram of the high-pressure pressing means. 3. A piston rod side cylinder chamber and a counter-cylinder chamber can communicate with each other when only one of the first hydraulic type opening / closing means and the second hydraulic type opening / closing means is driven. The mold clamping device according to claim 1.