JPH04168004A - Clamping apparatus - Google Patents

Abstract

PURPOSE:To simplify the structure, and thus reduce the costs, and improve the operability by disposing a pressing part on the side of base plate of a movable platen, and employing a clamping cylinder disposed between the base plate and the pressing part and movably supported by a first cylinder guide provided on the base plate. CONSTITUTION:A mold open and closing cylinder 21 is disposed on a base plate 2 at the rear of a movable platen 5, and the piston 22 of the mold open and closing cylinder 21 is connected to a movable platen 5 via a rod 23, and then the cap side of the mold open and closing cylinder 21 is applied with pressurized oil so as to move the movable platen 5 by means of a piston 22 in the right direction, thus closing the mold, and the rod side is supplied with pressurized oil so as to move the movable platen 5 in the left direction, thus opening the mold. The movable platen 5 is moved along a tie-bar 4 extending through between a stationary platen 3 and the base plate 2, and mold closing is effected, and after the molds 6, 7 are brought into contact with each other, mold clamping is carried out. For mold clamping, a mold clamping cylinder 34 is arranged on the side end surface of the movable platen of the base plate 2.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a mold clamping device.

(Prior art) Conventionally, a molding material that has been heated and fluidized in a heating cylinder is injected into a mold under high pressure, cooled and solidified or hardened therein, and then the mold is opened to take out the molded product. As a mold clamping device for an injection molding machine, a booster type type is provided.

FIG. 3 is a diagram showing a booster type mold clamping device.

In the figure, a base plate 2 and a fixed platen 3 are erected on a frame 1, and tie bars 4 are disposed between them. The tie bars 4 slidably support a movable platen 5, and the movable platen 5 moves toward and away from the fixed platen 3.

A fixed mold 6 is mounted on the fixed platen 3, and a movable platen 5 is mounted on the fixed mold 6.
A movable mold 7 is disposed in the mold 7, and molding material is filled between the two molds 6 and 7 during the injection process.

The molds 6 and 7 are placed in contact when filling with molding material, but must be opened when removing the molded product. For this reason, the movable platen 5 is provided with a mold clamping device 8.

That is, a main cylinder 9 is formed behind the base plate 2, and a piston 10 is disposed to slide inside the main cylinder 9.

A main cylinder chamber 11 formed between the end surface of the histone 1O and the main cylinder 9 houses hydraulic fluid that causes the piston 10 to reciprocate. Therefore, the main cylinder chamber 11 is connected to a prefill pipe 13 via a prefill pulp 12.

Further, a booster cylinder 14 is formed in the center of the piston 10 in the axial direction.
A tubular booster 15 is disposed within 4 so as to be movable forward and backward. The booster 15 is connected to a pipe that extends rearward and supplies high-pressure hydraulic oil.

In the mold clamping device of the injection molding machine having the above configuration, the booster cylinder 14 is activated and a small amount of oil is supplied when the mold is closed at high speed. On the other hand, during high-pressure mold clamping or mold opening, the main cylinder 9 is operated, and high-pressure oil is supplied and discharged.

However, in the mold clamping device of the above-mentioned injection molding machine, a main cylinder 9 with a large diameter and a large stroke is used, so the amount of hydraulic oil required for opening and closing the mold is extremely large, and the dimensions of the prefill valve 12 are , it is necessary to increase the dimensions of the prefill piping 13, the tank capacity, etc., and energy efficiency deteriorates.

Furthermore, when generating the mold clamping force, the volume of the portion where the hydraulic pressure is raised to a predetermined pressure is large, and the time required to do so becomes long.

Furthermore, since the piston 10 moves integrally with the movable platen 5, its inertia increases, resulting in poor controllability during acceleration and deceleration.

Therefore, in order to solve the above problems, a cylinder type mold clamping device is provided which has a mold opening/closing cylinder with a small diameter and a large stroke and a mold clamping cylinder with a large diameter and a small stroke.

Fig. 4 is a diagram showing a conventional mold clamping device of the shutter opening/closing type; Fig. 4 (A) is a front view of the mold clamping device of the shutter opening/closing type;
Figure (B) is a side view of the shutter opening/closing type mold clamping device.

In the figure, a mold opening/closing cylinder 21 with a small diameter and a large stroke is shown.
is arranged behind the movable platen 5, and the piston 22 of the mold opening/closing cylinder 21 is connected to the movable platen 5 via a rod 23. When pressure oil is supplied to the cap side of the linear opening/closing cylinder 21, the piston 22 moves the movable platen 5 to the right to close the mold, and by supplying pressure oil to the rond side, the movable platen 5 is moved to the left. The mold is opened by moving it.

The movable platen 5 moves along a tie bar 4 extending between the fixed platen 3 and the base plate 2.

Then, after the mold is closed and both molds 6 and 7 come into contact,
Mold clamping is performed.

For the above-mentioned mold clamping, a mold clamping cylinder 24 having a large diameter and a small stroke is arranged on the end surface of the base plate 2 on the movable platen side. When pressure oil is supplied to the camp side of the nuclear mold clamping cylinder 24, the piston 25 moves to the right. The piston 25 is hollow with a through hole 26 formed in the center, and can accommodate a mold thickness adjusting threaded rod 27 when the mold is opened.

The mold thickness adjusting threaded rod 27 meshes with a nut 28 fixed to the back surface of the movable platen 5. Then, it becomes possible to change the relative position of the nut 28 and the mold thickness adjusting threaded rod 27 by the stroke amount in accordance with the thickness of both molds 6.7. The mold thickness adjusting screw stop 27 is rotated manually, by an electric motor, an oil motor, or the like.

By the way, a shutter 29 is provided between the front end surface of the piston 25 sliding on the mold clamping cylinder 24 and the rear end surface of the mold thickness adjusting threaded rod 27, and is moved forward and backward by the shutter driving cylinder 30a. . The mold clamping cylinder 24 is opened with the shutter 29 interposed between the front end surface of the piston 25 and the rear end surface of the mold thickness adjusting threaded rod 27.
When the cap side of the piston 25 is pressurized, the clamping force is generated by the piston 25,
It is transmitted to the movable mold 7 via the mold thickness adjusting threaded rod 27, the nut 28, and the movable platen 5.

A shutter clearance adjustment mechanism 31 is provided so that the shutter 29 can be accurately interposed between the front end surface of the piston 25 and the rear end surface of the mold thickness adjusting threaded rod 27. The relative position of can be changed.

(Problem to be solved by the invention If) However, in the mold clamping device having the above configuration, it is necessary to interpose the shutter 29 between the front end surface of the piston 25 and the rear end surface of the mold thickness adjusting threaded rod 27. Therefore, the length of the mold clamping device increases, and the exclusive space of the injection molding machine increases.

Further, in order to move the shutter 29 stably and to adjust the gap between the piston 25 of the mold clamping cylinder 24 and the shutter 29, a shutter gap adjustment mechanism 31 or the like is required.
Not only does the number of parts increase and the cost rise, but the structure becomes complicated and operations become complicated.

Furthermore, since the shutter 29 is movable in the axial direction (in the direction of the tie bars 4), its opening and closing operations become unstable.

The present invention solves the problems of the conventional mold clamping device described above, reduces the number of mechanical parts required for mold clamping operation, simplifies the structure, reduces costs, and improves operability. The purpose is to provide a mold clamping device.

(Means for Solving the Problems) For this purpose, the present invention provides a mold clamping device of the present invention, which includes a fixed platen, a base plate disposed opposite to the fixed platen, and a base plate disposed between the fixed platen and the base plate. a movable platen that is disposed along the tie bar so as to be able to move toward and away from a fixed platen; and a mold that is connected between the base plate and the movable platen and closes and opens the mold by moving the movable platen. an opening/closing cylinder, a pressing part disposed on the base plate side of the movable platen, and a mold clamp disposed between the base plate and the pressing part and movably supported by a first cylinder guide provided on the base plate. It has a cylinder.

The nuclear mold clamping cylinder moves to a position where the piston and the above-mentioned pressing part face each other when the mold is clamped, and moves to a position away from the above-mentioned position when the mold is closed and opened. There is.

The mold clamping cylinder is connected to a mold clamping cylinder driving means, and the mold clamping cylinder driving means is supported by a second cylinder guide provided on the base plate.

The first cylinder guide may be a tie bar, the mold clamping cylinder may be swingably supported by the tie bar, and the second cylinder guide may be a tie bar.

The first cylinder guide may linearly guide the mold clamping cylinder.

(Function) According to the present invention, as described above, a fixed platen, a base plate disposed opposite to the fixed platen, a tie bar disposed between the fixed platen and the base plate, and a tie bar arranged along the tie bar. It has a movable platen that is arranged to be able to move toward and away from the fixed platen, and a mold opening/closing cylinder that is connected between the base plate and the movable platen and closes and opens the mold by moving the movable platen.

Therefore, by supplying pressure oil to the mold opening/closing cylinder, the movable platen is moved left and right, the mold is closed,
Can open the mold.

The movable platen also includes a pressing section disposed on the base plate side, and a mold clamping cylinder disposed between the base plate and the pressing section and movably supported by a first cylinder guide provided on the base plate. have. Therefore, the pressing portion of the movable platen can be pressed by operating the mold clamping cylinder.

When the mold is clamped, the mold clamping cylinder moves to a position where the piston and the pressing part meet, and when the mold is closed and opened, it moves to a position away from the above position. It has become. Therefore, the mold clamping cylinder can be operated only when necessary to press the movable platen against the fixed platen.

The mold clamping cylinder is connected to a mold clamping cylinder driving means, and the mold clamping cylinder driving means is supported by a second cylinder guide provided on the base plate. Therefore, the mold clamping cylinder can be moved by operating the mold clamping cylinder driving means.

The first cylinder guide may be a tie bar, and the mold clamping cylinder may be swingably supported by the tie bar, and the second cylinder guide may be a tie bar.

The first cylinder guide may linearly guide the mold clamping cylinder.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a mold clamping device of the present invention, and FIG. 2 is a side view of the mold clamping device of the present invention.

In the figure, a mold opening/closing cylinder 21 with a small diameter and a large stroke is shown.
is arranged on the base plate 2 behind the movable platen 5, and the piston 22 of the mold opening/closing cylinder 21 is connected to the rod 23.
It is connected to the movable platen 5 via. When pressure oil is supplied to the cap side of the mold opening/closing cylinder 21, the piston 22 moves the movable platen 5 to the right to close the mold, and by supplying pressure oil to the rond side, the movable platen 5 is moved to the left. The mold is opened by moving it.

The movable platen 5 moves along a tie bar 4 extending between the fixed platen 3 and the base plate 2.

Then, after the mold is closed and the molds 6°7 come into contact, mold clamping is performed.

For the above mold clamping, a mold clamping cylinder 34 with a large diameter and a small stroke is disposed on the end surface of the base plate 2 on the movable platen side. When pressure oil is supplied to the mold clamping cylinder 34,
The piston 35 moves to the right and the mold thickness adjustment threaded rod 2
7 is pressed.

The mold thickness adjusting screw 27 can be engaged with a nut 28 fixed to the back surface of the movable platen 5. Then, it becomes possible to change the relative position of the nut 28 and the mold thickness adjusting threaded rod 27 by the stroke amount in accordance with the thickness of the mold 6.7. The mold thickness adjusting threaded rod 27 is rotated manually, by an electric motor, an oil motor, or the like.

The mold thickness adjusting threaded rod 27 is pressed to the right by the mold clamping cylinder 34 during mold clamping, but the mold clamping cylinder 34 swings as described later and is used for mold thickness adjustment. The movable platen 5 moves to a position away from the threaded rod 27.
When it moves to the left, it can pass through the center hole 30 of the base plate 2.

The mold clamping cylinder 34 also has a head side oil chamber 37 on the base plate 2 side of the piston 35 and a rod side oil chamber 38 on the movable platen 5 side, and has a head side hydraulic circuit hole 39 in the head side oil chamber 37. A rod-side hydraulic circuit hole 40 is formed in the rod-side oil chamber 38, and the head-side oil chamber 37 and the rod-side oil chamber 3 are connected via both hydraulic circuit holes 39 and 40. Note that 36 is a flange.

The mold clamping cylinder 34 configured as described above is rotatably supported by a mold clamping cylinder guide 43 attached to the base plate 2. Therefore, the mold clamping cylinder 34 has an arm 45 extending between it and the mold clamping cylinder guide 43. An arm 46 is integrally formed on the opposite side of the arm 45 across the mold clamping cylinder guide 43,
The arm 45. is centered around the mold clamping cylinder guide 43.
46 is designed to swing.

A mold clamping cylinder rotation drive shaft 47 is rotatably attached to the tip of the arm 46. The core mold clamping cylinder rotation drive shaft 47 is fastened to the piston 49 of the mold clamping cylinder rotation drive cylinder 48 . Further, the mold clamping cylinder rotation driving cylinder 48 has a cylinder guide 50.
The cylinder guide 50 is also fixed to the base plate 2.

Therefore, the mold clamping cylinder rotation driving cylinder 48
By supplying pressure oil inside the mold clamping cylinder 34, it is possible to swing the mold clamping cylinder 34 via the arms 45 and 46.

Although the mold clamping cylinder guide 43 supports the mold clamping cylinder 34 in a swingable manner, it is not necessarily necessary to support the mold clamping cylinder 34 in a swingable manner. Good too.

When performing mold opening/closing operations in the mold clamping device with the above configuration,
Pressure oil is supplied to the rod-side oil chamber 38 of the mold clamping cylinder 34 to move the piston 35 backward. Then, while the piston 35 is retracted, hydraulic pressure is maintained in the rod-side oil chamber 51 of the mold clamping cylinder rotation driving cylinder 48, and the piston 4
9 is moved back, the mold clamping cylinder 34 swings and is removed from between the center hole 30 of the base plate 2 and the mold thickness adjusting screw stud 27.

In this state, pressure oil is supplied to the rod-side oil chamber 54 or the head-side oil chamber 55 of the mold opening/closing cylinder 21 to move the movable platen 5 backward (mold opening operation) or forward (mold closing operation). Since the mold clamping cylinder 34 is not interposed between the center hole 30 and the mold thickness adjustment screw rod 27, the clamping cylinder 34 and the mold thickness adjustment screw rod 27, which are fastened to the movable platen 5, can be easily centered. It can pass through the hole 30.

Next, during the mold closing operation, pressurized oil is supplied to the head side oil chamber 55 of the mold opening/closing cylinder 21 to move the movable platen 5 forward. Then, with the fixed mold 6 and the movable mold 7 in close contact or close to each other, pressurized oil is supplied to the head side oil chamber 52 of the mold clamping cylinder driving cylinder 48 to move the piston 49 forward. 34 is interposed between the pressing part outside the center hole 3o of the base plate 2 and the die thickness adjusting screw rod 27.

In addition, with the movable platen 5 moved to the forward limit,
The nut 28 and the threaded rod 27 for adjusting the mold thickness are adjusted in advance, and the distance between the base plate 2 and the threaded rod 27 for adjusting the mold thickness is kept constant.

The adjustment screw 27 may be a simple rod, and the mold pressure adjustment portion may be provided with a tie bar adjustment nut separately.

That is, when the piston 35 of the mold clamping cylinder 34 is at the retraction limit, the tip surface B of the base plate 2 and the piston 35
The distance BD between the tip surface B of the base plate 2 and the tip surface of the threaded rod 27 for adjusting the mold thickness is set slightly larger than the distance BC between the tip surface C and the tip surface C of the base plate 2. .

Assuming that the stroke of the piston 35 is ST, when the movable platen 5 is at the forward limit and the piston 35 is at the backward limit, the relationship is BD>BC, BD<BC+ST.

Therefore, the mold clamping cylinder 34 can easily pivot between the mold thickness adjusting draw rod 27 and the center hole 30 of the base plate 2 in accordance with the operation of the mold clamping cylinder driving cylinder 48.

Then, with the mold clamping cylinder 34 interposed between the center hole 30 of the base plate 2 and the mold thickness adjustment threaded rod 27, pressure oil is supplied to the hand side oil chamber 37 of the mold clamping cylinder 34, A mold clamping force can be generated by bringing the piston 35 into pressure contact with the tip of the threaded rod 27 for adjusting mold thickness.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

For example, in the above embodiment, a nut is provided on the movable platen in order to adjust the mold pressure, and a mold thickness adjustment screw rod that engages with the nut is provided, but the mold thickness adjustment mechanism is placed on the tie bar side. The movable platen may be provided with a fixed center rod integrally formed therein.

(Effects of the Invention) As described above in detail, the mold clamping device of the present invention includes a pressing part disposed on the base plate side of the movable platen, and a pressing part disposed between the base plate and the pressing part, It has a mold clamping cylinder movably supported by a provided first cylinder guide. Therefore, the pressing portion of the movable platen can be pressed by operating the mold clamping cylinder.

Therefore, since there is no need to interpose a shutter between the mold clamping cylinder and the movable platen, the overall length of the mold clamping device is shortened, and the dedicated space of the injection molding machine is reduced.

In addition, since there is no shutter, the number of parts is reduced and costs can be reduced, and the structure is simplified and operability is improved.

The mold clamping cylinder is connected to a mold clamping cylinder driving means, and the mold clamping cylinder driving means is supported by a second cylinder guide provided on the base plate. Therefore, the mold clamping cylinder can be moved by operating the mold clamping cylinder driving means.

Since the mold clamping cylinder is fixed to the cylinder guide, replacement as an assembly is easy and maintainability is good.

The first cylinder guide may be a tie bar, and the mold clamping cylinder may be swingably supported by the tie bar, and the second cylinder guide may be a tie bar. In this case, the number of parts can be further reduced. can.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a mold clamping device of the present invention, Fig. 2 is a side view of the mold clamping device of the present invention, Fig. 3 is a diagram showing a booster type mold clamping device, and Fig. 4 is a diagram showing a conventional shirt clamp device. FIG. 4(A) is a front view of the shutter opening/closing type mold clamping device, and FIG. 4(B) is a side view of the shutter opening/closing type mold clamping device. 2... Base plate, 3... Fixed platen, 4...
... Tie bar, 5... Movable platen, 6... Fixed mold, 7... Movable mold, 21... Mold opening/closing cylinder, 27
...Drilling rod for mold thickness adjustment, 28...Nut, 3o
...Center hole, 34...Mold clamping cylinder, 35...
Piston, 43 River mold clamping cylinder guide, 47 first cylinder guide, 48... cylinder for mold clamping cylinder rotational drive, 50... second cylinder guide.

Claims (5)

[Claims] (1) (a) a fixed platen; (b) a base plate disposed opposite to the fixed platen; (c) a tie bar disposed between the fixed platen and the base plate; (d) a tie bar disposed on the tie bar. (e) a mold opening/closing cylinder that is connected between the movable platens and closes and opens the mold by moving the movable platen; (f) a pressing part disposed on the base plate side of the movable platen; (g) a mold clamping cylinder disposed between the base plate and the pressing part and movably supported by a first cylinder guide provided on the base plate; (h) The mold clamping cylinder moves to a position where the piston and the pressing part face each other when the mold is clamped, and moves to a position away from the above position when the mold is closed and opened. A mold clamping device characterized by moving. (2) The mold clamping cylinder according to claim 1, wherein the mold clamping cylinder is connected to a mold clamping cylinder driving means, and the mold clamping cylinder driving means is supported by a second cylinder guide provided on the base plate. Device. (3) The mold clamping device according to claim 1, wherein the first cylinder guide is a tie bar, and the mold clamping cylinder is swingably supported by the tie bar. (4) The mold clamping device according to claim 3, wherein the second cylinder guide is a tie bar. (5) The mold clamping device according to claim 1, wherein the first cylinder guide guides the mold clamping cylinder linearly.