JP2901511B2 - Molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus having a mold clamping cylinder for opening and closing a mold.

[0002]

2. Description of the Related Art In an injection molding machine, a mold clamping device is required to have the following functions in terms of molding operation and production efficiency. That is, as the operation of the mold clamping device, at the initial and final stages of opening and closing the mold and at the time of ejecting the molded product, the moving speed of the mold is reduced to prevent the mold and the molded product from being damaged by impact. There is a need to. Further, during the period from the start of injection of the molten resin to the cooling and solidification of the mold after the mold is closed, it is necessary to tighten the mold with a force higher than that so as not to open the mold due to the pressure of the resin in the mold. Further, after the molded product is solidified, it is necessary to quickly open the mold by a stroke necessary for taking out the molded product.

[0003] In an injection molding machine, a crank mechanism having a crankshaft rotated in a fixed direction by a hydraulic motor is connected to a toggle mechanism having a link mechanism connecting a movable die plate guided by a tie bar and a fixed die plate. A toggle machine type clamping device equipped with a cam corresponding to the moving position of the movable die plate on the crankshaft and a speed adjustment unit operated by this cam to change the rotation speed of the hydraulic motor, 46-2192. In addition, as a mold clamping device that enables mold clamping with a small and small output motor, the rotation of the motor is converted to linear movement via a ball screw, and the linear movement is transmitted to a link mechanism via a rod. The linear movement of the ball screw is transmitted to the piston reciprocating in the cylinder, and the hydraulic pressure generated in the cylinder is branched into two pipes. Japanese Patent Application Laid-Open No. 1-146721 discloses a configuration in which one cylinder is directly connected to the other cylinder by a pipeline, and when a low speed and high torque is required, the switching valve is switched to be driven by two cylinders. Has become.

[0004] However, in the above-described mold clamping device of the toggle mechanical system, the control is simple, but when the mold is replaced, there is a problem that it is difficult to set the mold clamping force due to a change in the mold thickness. there were.

As a mold clamping device, besides the toggle machine system described above, there is a direct pressure system using a high-pressure, low-speed mold clamping cylinder for strongly clamping a mold. In the direct pressure type that uses such a mold clamping cylinder, the mold clamping cylinder opens and closes the mold at low speed by supplying hydraulic oil from the drive pump. I try to get the tightening force.

However, in a molding apparatus using such a mold clamping cylinder, since a low-speed mold clamping cylinder is used to obtain a high pressure and strong mold clamping force, it takes time to open and close the mold. However, there is a problem that the molding cycle is long. For this reason, there is a mold clamping cylinder in which a high-speed opening / closing cylinder is provided.

[0007]

However, in the above-described one in which the high-speed opening / closing cylinder is provided in the mold-clamping cylinder, the structure is complicated and the amount of hydraulic oil from the drive pump is controlled. When closing the mold, the mold closing cylinder is operated following the operation of the high-speed opening / closing cylinder.
At the time of opening the mold, it is necessary to operate the high-speed opening / closing cylinder following the operation of the mold clamping cylinder, and there is a problem that the speed control is particularly difficult.

Accordingly, an object of the present invention is to shorten the molding cycle and increase the efficiency by enabling the mold closing cylinder to open and close the mold at high speed without requiring a complicated structure or speed control. The object of the present invention is to provide a molding apparatus capable of achieving the above. A further object of the present invention is to make it possible to easily cope with a change in a mold in a molding apparatus having such a mold clamping cylinder.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is a molding apparatus including a pair of molds for forming a cavity, and a mold clamping cylinder for opening and closing the molds. Supply working fluid to the mold clamping cylinder.
A paper driving pump, and the high-speed opening and closing pump for opening and closing said mold by supplying a working fluid to the mold clamping cylinder at high speed, so as to gradually decelerate the fast opening and closing the pump gradually after accelerated Unequal speed drive means for unequal speed operation and front
When the mold is strongly clamped at high pressure, the drive pump
Switching operation to supply the working fluid of
And a switching valve that switches the height of the unequal speed driving means.
A link mechanism for causing the speed opening / closing pump to perform unequal speed movement;
And a drive source for swinging the link mechanism .

[0010] Further, the invention according to claim 2 is based on claim 1.
In the described invention, the driving source is the driving pump.
The link mechanism is swung by taking in the working fluid
It is characterized in that it is a swinging cylinder.

[0011] The invention according to claim 3 is based on claim 1.
Or in the invention described in 2, wherein the link mechanism is
A lever connected to a driving source, and the lever and the high-speed opening
An arm that connects the pump with the closing pump.
Wherein the lever is provided with a length adjusting means.
And

Further, according to a fourth aspect of the present invention, the cavity
And a mold clamp for opening and closing the mold.
In the molding apparatus comprising a cylinder, wherein the clamping Siri
And driving the pump supplying hydraulic fluid to Sunda, the mold clamping Siri
The mold is supplied with a working fluid to open and close the mold at high speed.
High-speed opening and closing pump and this high-speed opening and closing pump gradually
To operate at an irregular speed so that the speed gradually increases and then gradually decelerates.
Constant-speed driving means, when strongly clamping the mold at high pressure
The working fluid from the drive pump is supplied to the mold clamping cylinder.
And a control valve for switching operation to supply the non-uniform
The driving means causes the high-speed on / off pump to perform the unequal speed operation.
And the rotating mechanism of this crank mechanism
And a driving source for driving the motor.

Further, the invention described in claim 5 is the invention according to claim 4.
In the described invention, the driving source is the crank mechanism.
It is an electric motor that rotates
You.

The invention according to claim 6 is the invention according to claim 4.
In the invention described in (5), the crank mechanism includes a rotor that is rotationally driven by the drive source, a crankpin provided on the rotor, and an arm that connects the crankpin and the high-speed on / off pump. In addition, the rotor is provided with a position adjusting means for the crankpin.

[0015]

According to the first aspect of the present invention, the working fluid is supplied to the mold clamping cylinder by the high-speed opening / closing pump which is operated at an unequal speed so that the speed is gradually increased and then gradually reduced by the unequal speed driving means. By doing so, the mold can be opened and closed at a high speed. Then, the switching valve is switched to drive.
To supply working fluid from the pump to the mold clamping cylinder
Therefore, the mold is strongly clamped at high pressure by the mold clamping cylinder.
Can be Conversely, strong mold opening can also be
You. It should be noted that the unequal-speed driving means is configured as described in claim 1.
If this is achieved, the link mechanism will be oscillated by driving the drive source.
To make the high-speed on / off pump perform the unequal speed operation.
And the operation supplied from the high-speed on / off pump
High-speed operation of the mold clamping cylinder can be performed by the fluid.

Further, as in the second aspect of the present invention,
If the drive source for the constant speed drive means is configured, the drive
Swing the link mechanism by taking in the working fluid from the dynamic pump
Since it is operated, it is separate from the drive pump for the mold clamping cylinder.
There is no need to provide multiple drive sources.

According to the third aspect of the present invention, the drive
A lever connected to the power source,
Link machine consisting of an arm connecting to a pump
In the construction, the lever is provided with length adjustment means
By changing the lever length, the mold thickness changes
The stroke of the mold clamping cylinder can be adjusted according to.

According to the invention described in claim 4, according to claim 1,
Similarly, gradually increase the speed by the unequal speed drive, and gradually
High-speed opening / closing pump that operates at irregular speed
By supplying working fluid to the mold clamping cylinder,
The mold can be opened and closed at high speed. And switching
The valve is switched so that the working fluid from the drive pump is
By supplying to the cylinder, the mold clamping cylinder
The mold can be strongly clamped at high pressure. On the contrary, strong
Force opening is also possible. In addition, according to claim 4
If the unequal-speed driving means is configured as described above,
Rotate the crank mechanism to create a high-speed open / close pump.
High-speed opening and closing by performing the unequal speed operation
The working fluid supplied from the pump
High-speed operation can be performed.

Further, as in the fifth aspect of the present invention,
If the drive source of the constant speed drive means is configured,
The crank mechanism is rotated by an electric motor separate from the drive pump.
Rolled.

According to the sixth aspect of the present invention, there is provided a rotor which is rotationally driven by a drive source , a crankpin provided on the rotor, and an arm connecting the crankpin and the high-speed opening / closing pump. In the crank mechanism described above, the rotor is provided with a means for adjusting the position of the crank pin, so that by adjusting the position of the crank pin, the stroke of the mold clamping cylinder can be adjusted in accordance with the change in the mold thickness.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a molding apparatus according to the present invention will be described below with reference to FIGS. First, FIG. 1 shows an injection molding machine as an example of a molding apparatus to which the present invention is applied, and is a schematic configuration diagram showing a first embodiment of a main device including a hydraulic circuit. In FIG. 1, 1 is a fixed plate, 2 is a fixed die, 3 is a movable plate, 4 is a movable die, 5 is a tie bar, 6 is a mold clamping cylinder, 11 is a plasticizing means, 15 is an injection cylinder, and 18 is a hydraulic pressure. Motor, 21 is a drive pump, 22 is an injection piston pump, 31 is a high-speed opening / closing piston pump,
Non-uniform speed drive means 34, 35 the link mechanism, the swing cylinder 41, Mi, Mp electric motor, Psw pressure switch, T is _{tank, V 1, V 2, V} 3, V 4, V 5 is electromagnetic switching valve, Vbp the back pressure control valve, Vpp is the pressure control valve, V _A, V _B,
V _C, V _D, V _E is a check valve, V _F is the relief valve, W is a molded article.

That is, as shown in the drawing, a fixed die 2 is mounted on a fixed platen 1 and a movable die 4 is mounted on a movable platen 3, and the movable platen 3 is fixed along a tie bar 5.
Move freely in the directions. A cavity for obtaining a molded product W is formed between the fixed mold 2 and the movable mold 4 in the mold clamped state. Then, the movable platen 3 is driven by the mold clamping cylinder 6. This mold clamping cylinder 6 is provided with a mold clamping ram 8 connected to a piston 7 that slides inside the mold clamping ram 8, and this mold clamping ram 8 is connected to the movable platen 3. Further, the plasticizing means 11 includes a nozzle capable of penetrating through the fixed platen 1 and contacting the fixed mold 2, and is connected to a cavity formed in a mold clamped state with the movable mold 4.
And a screw 13 slidably and rotatably incorporated in the heating cylinder 12, a hopper 14 for supplying a raw material into the heating cylinder 12, an injection cylinder 15 for moving the screw 13, and rotating the screw 13. And a hydraulic motor 18. The injection cylinder 15 is provided with an injection ram 17 connected to a piston 16 that slides inside the cylinder.
The injection ram 17 is connected to the screw 13.

A drive pump 2 for supplying a working fluid as a working fluid to the mold clamping cylinder 6 and the injection cylinder 15.
1 is provided. The drive pump 21 is of a variable displacement (variable discharge amount) type driven by an electric motor Mp to pump hydraulic oil from a tank T. An oil passage from the drive pump 21 to the injection cylinder 15 is provided with an injection piston pump 22 for taking in the hydraulic oil once and then feeding the hydraulic oil to the injection cylinder 15. The injection piston pump 22 is provided with a ram 24 connected to a piston 23 that slides inside. In the illustrated example, the area (diameter) of the piston 23 is equal to the area (diameter) of the piston 16 of the injection cylinder 15. The arm 25 is connected to the ram 24 via a pivot pin 26. Further, a crank pin 27 is connected to the arm 25, and the crank pin 27 is provided on a rotor 28. This rotor 28 is driven to rotate by an electric motor Mi via a power transmission belt 29. This is the unequal speed driving means.

The drive pump 21 is used to move the mold clamping cylinder 6
A high-speed opening / closing piston pump 31 for feeding hydraulic oil to the mold-clamping cylinder 6 is provided in the oil passage. This high-speed opening / closing piston pump 31 is provided with a ram 33 connected to a piston 32 that slides inside. In the illustrated example, the area (diameter) of the piston 32 is set larger than the area (diameter) of the piston 7 of the mold clamping cylinder 6, and the ram 33 is connected to the unequal-speed driving means 34. In the first embodiment, the unequal-speed driving means 34 includes a link mechanism 35 and an oscillating cylinder 41 as a driving source thereof. The link mechanism 35 includes an arm 36 and a lever 39
And also serves as a toggle mechanism (power boost mechanism). That is, the arm 36 is connected to the ram 33 via a pivot pin 37 and a lever 39 is connected to the arm 36 via a pivot pin 38. This lever 3
Numeral 9 is swingable with the pivot pin 40 as a fulcrum, and the length can be adjusted by a nesting structure using an adjusting screw 39a. That is, this is the length adjusting means of the lever 39. The swing cylinder 41 includes a pivot pin 42.
The piston 43 that can swing freely around the fulcrum and slides inside
Is connected to the lever 39 via a pivot pin 45.

An oil passage from the drive pump 21 to the mold clamping cylinder 6 and the high-speed opening / closing piston pump 31 includes:
Two three-position switching electromagnetic switching valves V ₁ and V ₂ are provided, and one three-position switching electromagnetic switching valve V ₃ is also provided in the oil passage from the drive pump 21 to the swing cylinder 41. Is provided. Also, the oil passage from the drive pump 21 to the injection cylinder 15 and the injection piston pump 22
Two position switching type electromagnetic switching valves V ₄ and V ₅ are provided. Further, as shown, a pressure control valve Vpp for the driving pump 21, a back pressure control valve Vbp for the injection cylinder 15, a pressure switch Psw for the mold clamping cylinder 6, and the like are provided. Piston pump 3
Check valve V _A for _{1, V B, V C,} V D, V E and the relief valve V _F is provided (see FIG. 2).

In FIG. 2, the high-speed opening / closing piston pump 31 has a diameter D ₀ of the piston 7 of the mold clamping cylinder 6, a diameter d ₀ of the clamping ram 8, and a high-speed opening / closing stroke St _0.
The diameter D ₁ of the piston 32, the diameter d ₁ of the ram 33, when the stroke St _1, from the relationship of the ^{_{volume, (πD 0 2/4)}} × St 0 = (πD 1 2/4) × St 1 {π ^{_{(D 0 2 -d 0 2)}} / 4} × St 0 = {π (D 1 2 -d 1 2) / 4} D 0 which satisfies _{× St 1, d 0, St} 0, D 1, d 1 , St ₁ are determined. The mold clamping cylinder 6 and the high-speed opening / closing piston pump 31 may be of a direct connection type. In this case, the capacity A of the mold clamping cylinder 6 and the high-speed opening / closing piston pump 31
The relationship of the capacity B is set such that A <B in terms of the oil amount in consideration of the strong mold clamping at high pressure.

FIG. 3 is a diagram showing the relationship between the components of the unequal speed drive means. In the case of the unequal speed drive means for the injection piston pump 22, the length L of the arm 25, the rotor 28
From the center of rotation of the crank pin 27, the rotation angle θ of the crank pin 27 (rotor 28), the point of connection of the arm 25 to the ram 24 from the center of rotation of the rotor 28 at the initial position before rotation (the pivot pin 26). ), And the stroke St of the injection piston pump 22 is St = L + R−a, and a = Rcos θ + [L ² − (Rsin θ) ² ] ^1/2 , so that St = L + R −Rcos θ− [L ² − (R sin θ) ² ] ^1/2 = L + (1−cos θ) R− [L ² −R ² sin ² θ] ^1/2 Here, since L is constant, the rotation angle
By changing θ or R, St can be changed. Note that the stroke St is from the illustrated state to a state in which the center of the arm 25, the crankpin 27, and the rotor 28 is horizontally aligned.

Similarly, in FIG. 3, in the case of the unequal-speed driving means 34 of the high-speed opening / closing piston pump 31,
L, the length R of the lever 39, the rotation angle θ of the lever 39, the distance from the swing center of the lever 39 at the initial position before swing to the connection point (pivot pin 37) of the arm 36 to the ram 33. The distance a and the stroke St of the high-speed opening / closing piston pump 31 are also represented by St = L + (1−cos θ) R− [L ² −R ² sin ² θ] ^1/2 . Therefore, also in this case, since L is constant, St can be changed by changing the rotation angle θ or R. The stroke St is from the illustrated state to the state in which the arm 36 and the lever 39 are aligned horizontally.

Next, the operation of the injection molding machine according to the first embodiment will be described. FIG. 4 is a timing chart showing the operation control of the main device of FIG. 1. As shown in this timing chart, five electromagnetic switching valves V
₁ , V ₂ , V ₃ , V ₄ , V ₅ , pressure control valve Vpp for drive pump 21, pressure switch Psw for mold clamping cylinder 6, electric motor Mi for driving injection piston pump 22, for injection cylinder 15 Operate the respective back pressure control valves Vbp. First, mold clamping is performed in two stages: high-speed mold closing followed by strong mold clamping. That is, two electromagnetic switching valves V ₁ and V ₂ provided in an oil passage from the drive pump 21 to the mold clamping cylinder 6 and the high-speed opening / closing piston pump 31, and an oil passage provided in the oil passage from the drive pump 21 to the swing cylinder 41. The other electromagnetic switching valve V ₃ is switched from the intermediate position (the state shown) to the position b, and the pressure control valve Vpp for the drive pump 21 is turned off.
N operations are performed. By the ON operation of the pressure control valve Vpp, a required amount of hydraulic oil is supplied from the variable displacement (variable discharge amount) type drive pump 21.

As described above, the hydraulic oil from the drive pump 21 is supplied to the oil chamber on the piston rod 44 side of the swing cylinder 41 through the electromagnetic switching valve V ₃ in the switching state to the position b, and the piston 43 is moved. By moving down inside the swing cylinder 41, the lever 39 is swung via the piston rod 44 and the pivot pin 45. The swing of the lever 39 is performed counterclockwise with the pivot pin 40 as a fulcrum. At the same time, the swing cylinder 41 also swings counterclockwise with the pivot pin 42 as a fulcrum. The swinging of the lever 39 in the counterclockwise direction about the pivot pin 40 as a fulcrum
Is transmitted to the arm 36 via the arm 36 and is converted from the arm 36 into a linear motion of the ram 33 via the pivot pin 37.
When converting the linear motion of the ram 33 from the arm 36 performing the unequal-velocity motion, a force based on the ratio of the length of the lever 39 to the length of the arm 36 is applied. The swing cylinder 4
The hydraulic oil in the oil chamber on the rear side of the first piston 43 is b
Tank T via the solenoid-operated directional control valve V ₃
Returned to

Further, the piston 32 integrated with the ram 33 advances leftward in the piston pump 31 for high-speed opening and closing.
The working oil in the oil chamber is supplied to the oil chamber on the back side of the piston 7 of the mold clamping cylinder 6. As a result, the piston 7 advances rightward in the mold clamping cylinder 6 to advance the movable platen 3 provided in the mold clamping ram 8, that is, the movable mold 4 advances in the direction of the fixed mold 2. Here, due to the switching operation of the electromagnetic switching valves V ₁ and V _{2 from} the intermediate position (the state shown) to the position b, the hydraulic oil from the drive pump 21 stops the check between the mold clamping cylinder 6 and the high-speed opening / closing piston pump 31. guided valve V _a, to V _B, respectively, the check valve V _a, V _B are respectively opened. Therefore, there is no pressure loss when the hydraulic oil is supplied from the high-speed opening / closing piston pump 31 side to the mold clamping cylinder 6 side. Therefore, the hydraulic oil in the oil chamber due to the forward movement of the piston 32 in the high-speed opening / closing piston pump 31 moves to the left without causing a pressure loss due to the check valve _VA. Is supplied smoothly. It is likewise, returned smoothly to the oil chamber of the ram 33 side of the high-speed opening and closing piston pump 31 without a pressure loss due to the mold clamping ram 8 side of the oil chamber of the hydraulic oil also a check valve V _B of the clamping cylinder 6 .

[0032] Incidentally, supply of hydraulic fluid to the back side of the oil chamber of the piston 32 of the high-speed opening and closing piston pump 31, a check valve V _C from the tank T by moving to the ram 33 side of the piston 32
This is done by pumping the oil through. Also, the hydraulic oil that moves back and forth between the oil chamber on the back side of the piston 32 of the high-speed opening / closing piston pump 31 and the oil chamber on the back side of the piston 7 of the mold clamping cylinder 6 via the check valve _VA is slightly increased. If there is excess oil, the slight surplus oil is returned to the tank T through the relief valve V _F. The supply of hydraulic fluid to the ram 33 side of the oil chamber of the high-speed opening and closing piston pump 31, the ram 33 of the piston 32 and by moving to the opposite side from the tank T via the check valve V _E by pumping oil Done.

In the above, a high-speed opening / closing piston pump is provided by the unequal-speed movement of the link mechanism 35 which also functions as a toggle mechanism (power-assisting mechanism) driven by the driving of the swing cylinder 41 by the supply of hydraulic oil from the drive pump 21. The piston 32 moves forward by increasing the speed non-linearly, reaches the maximum speed, and then slows down and stops. The operating oil pushed out of the oil chamber by the piston 32 is applied to the piston 7 of the mold clamping cylinder 6 by the piston 32. By supplying the oil to the oil chamber on the rear side, the mold clamping ram 8 moves forward in a non-linearly increasing manner at the same speed as the piston 32, reaches the maximum speed, and then slows down and stops. A high-speed mold closing operation of the movable mold 4 in the direction of the fixed mold 2 is performed. continue,
The movable mold 4 to the fixed mold 2 when strongly clamping at high pressure, in the three electromagnetic switching valve V _1, V _2, V _3, switching operation only one electromagnetic switching valve V ₁ to a position Then, the remaining two solenoid-operated directional control valves V ₂ , V ₃ are switched to the intermediate positions (shown). Accordingly, the hydraulic oil from the drive pump 21 is not supplied to the swing cylinder 41, the piston 7 of the mold clamping cylinder 6 via the electromagnetic switching valve V ₁ and the check valve V _D of the switching state to the a position Is supplied to the oil chamber on the back side of the mold, the mold clamping ram 8 advances at a low speed with a high pressure, and the strong mold clamping operation of the movable mold 4 with respect to the fixed mold 2 at a high pressure is performed.

Here, by the switching operation of the electromagnetic switching valve V ₁ to the position a, the hydraulic oil in the oil chamber on the back side of the piston 7 of the mold closing cylinder 6 stops the introduction of the hydraulic oil from the drive pump 21. and the check valve V _a which in the closed state is, is kept to a high pressure state is prevented the return by the presence of the check valve V _D. Incidentally, the hydraulic oil in the oil chamber of the mold clamping ram 8 side of the mold clamping cylinder 6 is returned to the tank T via the electromagnetic switching valve V ₂ in the switching state to the intermediate position (the state shown).

If [0035] With the above strong clamping pressure switch Psw for mold clamping cylinder 6 has become ON, thereby switching the operation of the electromagnetic switching valve V ₁ to the intermediate position (illustrated state), the pressure for driving the pump 21 The control valve Vpp is turned off. Subsequently, after a slight time lag, the drive pump 21
From the injection cylinder 15 and the injection piston pump 22
While switching operation position b the oil passage to the two electromagnetic switching valve V ₄ which is provided, V one of the ₅ only electromagnetic switching valve V ₅ from the intermediate position (illustrated state) to, injection piston pump 22
The driving of the driving electric motor Mi is started. Accordingly, the rotor 28 starts to rotate counterclockwise via the power transmission belt 29, and the rotation of the crank pin 27 is converted into the linear motion of the ram 24 via the swing of the arm 25 and the pivot pin 26. When the linear motion of the ram 24 is converted from the arm 25 performing the unequal speed motion, the eccentric amount of the crank pin 27 from the center of the rotor 28 and the arm 2
A force based on the rotation angle ratio of 5 is applied. Further, the piston 23 integral with the ram 24 is used for the injection piston pump 2.
2, the hydraulic oil in the oil chamber is supplied to the oil chamber on the back side of the piston 16 of the injection cylinder 15.
As a result, the piston 16 advances leftward in the injection cylinder 15.

[0036] The switching operation to a position electrodeposition磁切valve V ₄ from the intermediate position (the state shown). Then, hydraulic oil from the drive pump 21, by the supplied directly to the rear side of the oil chamber of the piston 16 of the injection cylinder 15 via the electromagnetic switching valve V ₄ in the switching state to a position, during injection molding Is performed. Incidentally, the hydraulic oil in the oil chamber of the injection ram 17 side of the injection cylinder 15 is returned to the tank T via the electromagnetic switching valve V ₅ in the switching state to the b position.

When the necessary injection time including the holding pressure elapses, the two solenoid-operated directional control valves V ₄ and V ₅ are both switched to the intermediate positions (shown). This ends the pressure holding. Then, the cooling of the dies 2 and 4 is started as is well known. After a slight time lag,
The two electromagnetic switching valves V ₄ and V ₅ are both switched to the position b, and the back pressure control valve Vbp for the injection cylinder 15 is turned on. Further, the electric motor Mi is driven by reverse rotation. In rotation of the screw 13 driven by the hydraulic motor 18, in the heating cylinder 12, the raw material in front of the screw 13 is sent while being plasticized, predetermined weighing is carried out. In this measurement, the two electromagnetic switching valves V ₄ and V ₅ are both switched to an intermediate position (shown in the drawing) to turn off the back pressure control valve Vbp and to drive the electric motor Mi. Stop by terminating. Then, with a slight time lag, cooling end at the same time, while switching operation of the electromagnetic switching valve V ₁ to the position b, the ON operation of the pressure control valve Vpp. As a result, the pressure in the oil passage is released, and subsequently, the mold is opened after the pressure switch Psw is turned off.

This mold opening is performed in two stages: high-speed mold opening followed by high-speed mold opening, contrary to the case of mold clamping described above. That is, when the electromagnetic switching valve V ₂ is switched to the position a after the pressure release, the hydraulic oil from the drive pump 21 is supplied to the oil chamber on the mold clamping ram 8 side of the mold clamping cylinder 6, The piston 7 is retracted, and the movable mold 4 is strongly opened from the fixed mold 2 at low speed and high pressure. The hydraulic oil in the oil chamber on the back side of the piston 7 of the mold clamping cylinder 6 is b
Tank T via the solenoid-operated directional control valve V ₁
Returned to

Subsequently, when the electromagnetic switching valve V ₂ is switched to the position b and the electromagnetic switching valve V ₃ is switched to the position a, the operating oil from the drive pump 21 is switched to the position a. is supplied to the rear side of the oil chamber of the piston 43 of the swinging cylinder 41 through the electromagnetic switching valve V ₃ on the piston 43 is moved upward to the swing cylinder 41, the lever 39 via the piston rod 44 is The swing cylinder 41 swings clockwise, and at the same time, the swing cylinder 41 swings clockwise. Incidentally, the hydraulic oil in the oil chamber of the piston rod 44 side of the swing cylinder 41 is returned to the tank T via the electromagnetic switching valve V ₃ in the switching state to the a position.

The clockwise swing of the lever 39 is transmitted to the arm 36, which converts it into a linear motion of the ram 33 of the high-speed opening / closing piston pump 31, and the piston 32 retreats. oil chamber of the clamping ram 8 side of the oil chamber of the clamping cylinder 6 via the check valve V _B which is in the opened state with the introduction of the pilot pressure by electromagnetic switching valve V ₂ of the switching state of the hydraulic fluid to the b position To supply. As a result, the piston 7 retreats, and the movable mold 4 retreats. Therefore, the high-speed mold opening operation of the movable mold 4 with respect to the fixed mold 2 is performed. That is, the mold clamping ram 8 retreats by gradually increasing the speed non-linearly in the same manner as the piston 32, reaches the maximum speed, then slows down and stops. An opening operation is performed. Incidentally, the rear-side oil chamber of the hydraulic oil in the piston 7 of the mold clamping cylinder 6, a check valve V _A which is in the opened state with the introduction of pilot pressure by the electromagnetic switching valve V ₁ of the switching state to the b position After that, it is returned to the oil chamber on the back side of the piston 32 of the high-speed opening / closing piston pump 31. At the end of the above mold opening operation, wherein each switching operation in both the electromagnetic switching valve V _1, V _2, V ₃ intermediate position (illustrated state). Thus, one cycle of the injection molding is completed.

Next, a second embodiment of the present invention will be described. FIG. 5 shows an injection molding machine as an example of a molding apparatus to which the present invention is applied. Similar to FIG. 1 of the first embodiment, a schematic diagram showing a second embodiment of a main device including a hydraulic circuit is shown. It is a block diagram. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The different parts from the first embodiment will be described. The second embodiment is different from the first embodiment in that a constant discharge type driving pump 21 is provided.
And that the unequal speed driving means 34
Instead of the link mechanism 35 and the swing cylinder 41 and the electromagnetic switching valve V ₃ in the first embodiment is that using an electric motor Mc is a crank mechanism 46 and a drive source, other configurations Is the same as in the first embodiment.

The crank mechanism 46 includes an arm 47, a crank pin 49, and a rotor 51, and also serves as a toggle mechanism (power boosting mechanism). That is, the arm 47
Is connected to the ram 33 via a pivot pin 48, and a crank pin 49 is connected to the arm 47 thereof. The crank pin 49 is provided integrally with an adjustment piece 53 screwed into an adjustment screw 52 rotatably mounted along the radial direction of the rotor 51 as shown in an enlarged manner in FIGS. 6 to 8. I have. By rotating the adjustment screw 52 and changing the position of the adjustment piece 53 on the adjustment screw 52, the distance of the crank pin 49 from the center of the rotor 51 can be adjusted. That is, this is the position adjusting means of the crank pin 49. And the rotor 51
Is driven to rotate by an electric motor Mc via a power transmission belt 54.

[0043] When the non-uniform speed driving means 34 of the high-speed opening and closing piston pump 31 of the second embodiment of this, the length L of A over arm 47, the eccentric amount R of the crank pin 49 from the rotation center of the rotor 51, high Stroke S of piston pump 31 for quick opening and closing
When t is represented, St = 2R. Therefore, by changing R , St can be changed. The stroke St is changed from the state in which the arm 47 is horizontal and the center of the rotor 51 is located between the pivot pin 48 and the crank pin 49 as shown in FIG.
7 is a half round (180 ° rotation), and the center of the arm 47 and the crank pin 49 and the rotor 51 is to condition that the horizontal line again.

Next, the operation of the injection molding machine according to the second embodiment will be described. FIG. 9 is a timing chart showing the operation control of the main device of FIG. 5, and as shown in this timing chart, the electric motor Mc for driving the high-speed opening / closing piston pump 31, the pressure control valve Vpp for the driving pump 21, Two electromagnetic switching valves V ₁ and V ₂ , a pressure switch Psw for the mold clamping cylinder 6, an electric motor Mi for driving the injection piston pump 22, and two electromagnetic switching valves V ₄ and V
_5. The back pressure control valve Vbp for the injection cylinder 15 operates. Here, four electromagnetic switching valves V ₁ , V ₂ , V ₄ ,
The operation of V ₅ , the pressure switch Psw, and the back pressure control valve Vbp are the same as in the first embodiment, so that the description will be simplified below.

First, regarding the mold clamping in two stages of high-speed mold closing followed by strong mold clamping, two electromagnetic switching valves V ₁ and V _{2 are used.}
Are both switched from the intermediate position (the state shown) to the position b, and the high-speed opening / closing piston pump 31
The driving of the driving electric motor Mc is started. The electric motor Mc may have a constant rotation speed . Accordingly, the rotor 51 starts rotating in either clockwise or counterclockwise direction via the power transmission belt 54, and the crankpin 4
9 is converted into a linear motion of the ram 33 via the swing of the arm 47 and the pivot pin 48. When the linear motion of the ram 33 is converted from the arm 47 performing the unequal speed motion, a force based on the ratio of the eccentric amount of the crank pin 49 from the center of the rotor 51 to the rotation angle of the arm 47 is applied. You. Then, the piston 32 moves forward in the high-speed opening / closing piston pump 31 (moves forward by increasing the speed non-linearly, reaches the maximum speed, then slows down and stops), and clamps the hydraulic oil in the oil chamber. By supplying the oil to the oil chamber on the back side of the piston 7 of the cylinder 6, the piston 7 moves forward in the mold clamping cylinder 6, and the movable mold 4 is fixed to the movable mold 3 via the movable plate 3 provided on the mold clamping ram 8. Move forward in mold 2 direction. At this time, the mold clamping ram 8 moves forward at a high speed, and the mold closing operation of the movable mold 4 in the direction of the fixed mold 2 is performed at a high speed.

Subsequently, when the movable mold 4 is strongly and strongly clamped to the fixed mold 2 at a high pressure, the electromagnetic switching valve V ₁ is moved to the position a.
While each switching operation of the electromagnetic selector valve V ₂ to the intermediate position (illustrated state) to ON operation of the pressure control valve Vpp. By the ON operation of the pressure control valve Vpp, a required amount of hydraulic oil is supplied from the constant discharge type drive pump 21. This allows
Since hydraulic oil from the drive pump 21 is supplied to the oil chamber on the back side of the piston 7 of the mold clamping cylinder 6, the mold clamping ram 8 moves forward at a high pressure and at a low speed, and the movable mold 4 with respect to the fixed mold 2 is moved. Strong clamping operation at high pressure is performed. If this strong clamping by the pressure switch Psw is turned ON, thereby switching the operation of the electromagnetic switching valve V ₁ to the intermediate position (illustrated state) and OFF operation of the pressure control valve Vpp. Subsequently, after a slight time lag, as well as switching operation position b the electromagnetic switching valve V ₅ from the intermediate position (illustrated state), the electric motor Mi for driving injection piston pump 22
Is started, and thereafter, injection and pressure holding are performed in the same manner as in the first embodiment. The pressure control valve Vpp is turned ON at the start of pressure holding.

When the necessary injection time including the holding pressure elapses, the two electromagnetic switching valves V ₄ and V ₅ are both switched to the intermediate positions (shown in the figure), and the pressure control valve Vpp is switched to the intermediate position. OFF operation. This completes the pressure holding, and then the cooling of the dies 2 and 4 is started. Subsequently, after a slight time lag, the electromagnetic switching valve V ₄ ,
V ₅ is switched to the position b, and
The back pressure control valve Vbp for the injection cylinder 15 is turned on.
After a slight time lag, the electric motor Mi
Is driven in reverse rotation to gradually reduce its speed.
Thereby, the plasticizing means 1 is made in the same manner as in the first embodiment.
A predetermined weighing by 1 is performed. In the course of this measurement, the driving of the electric motor Mi is stopped. This metering is finished, subsequently, with a slight time lag, cooling end at the same time, while switching operation of the electromagnetic switching valve V ₁ to the position b, the ON operation of the pressure control valve Vpp. As a result, the pressure in the oil passage is released, and subsequently, the mold is opened after the pressure switch Psw is turned off.

As in the first embodiment described above, first, when the electromagnetic switching valve V ₂ is switched to the position a, the hydraulic oil from the drive pump 21 causes the mold clamping cylinder 6 to clamp. Directly supplied to the oil chamber on the ram 8 side, the piston 7 retreats, and the movable mold 4 opens strongly from the fixed mold 2 at low speed and high pressure. Subsequently, when the electromagnetic switching valve V ₂ is switched to the position b and the electric motor Mc is started to rotate, the rotor 5 is rotated via the power transmission belt 54.
1 starts to rotate in either clockwise or counterclockwise direction, the rotation of the crank pin 49 is converted into the linear motion of the ram 33 via the swing of the arm 47 and the pivot pin 48, and the piston 32 Then, the hydraulic oil in the oil chamber is supplied to the oil chamber on the mold clamping ram 8 side of the mold clamping cylinder 6. As a result, the piston 7 retreats, and the movable mold 4 retreats. Therefore, the high-speed mold opening operation of the movable mold 4 with respect to the fixed mold 2 is performed. At the end of the mold opening operation, the operation of the electric motor Mc is stopped, and both the electromagnetic switching valves V ₁ and V ₂ are switched to the intermediate positions (shown), respectively, and the back pressure control valve Vbp Is turned off. Thus, one cycle of the injection molding is completed.

As described above, according to the present invention, the high-speed opening / closing operation of the dies 2 and 4 by the mold clamping cylinder 6 is realized by using the high-speed opening / closing piston pump 31. Can be achieved. Then, the hydraulic control system is simple, and the rotation control when the electric motor Mc is used is also simple. Further, the mold clamping cylinder 6 may be a simple cylinder, and there is no need to incorporate a fast-forward cylinder or the like. In addition, the high-speed opening / closing piston pump 31 may be a low-pressure one and may be a simple hydraulic cylinder.

In the above embodiment, an injection molding machine is used as the molding apparatus. However, the present invention is not limited to this, and can be applied to other than the injection molding machine. Any device may be used. Further, in each of the above embodiments, the working fluid is oil, but a working fluid such as air other than oil may be used. The drive pump 21 is of a variable displacement (variable discharge amount) type in the first embodiment and a constant discharge amount type in the second embodiment.
The constant discharge amount type in the embodiment may be a variable displacement (variable discharge amount) type in the second embodiment. In addition, the configuration of the unequal-speed driving means is arbitrary, and it goes without saying that the specific detailed structure and the like can be appropriately changed.

[0051]

As described above, according to the molding apparatus according to the first aspect of the present invention, the high-speed opening / closing operation in which the speed is gradually increased by the non-uniform speed driving means and then the speed is gradually decelerated is performed. The working fluid can be supplied to the mold clamping cylinder by the pump for opening and closing the mold at high speed. In addition, unequal speed
The drive means swings the link mechanism by driving the drive source.
The pump for high-speed opening and closing
Make the roll. And it works from this high-speed opening and closing pump
High speed operation of the mold clamping cylinder by supplying fluid
Can be Therefore, in a molding apparatus using a high-pressure, low-speed type mold clamping cylinder, the opening and closing operation of the mold can be accelerated without requiring a complicated structure and speed control, and as a result, the molding cycle can be shortened. And high efficiency can be achieved. Also, the drive is activated by the switching operation of the switching valve.
Supply the working fluid from the dynamic pump to the mold clamping cylinder,
The mold can be strongly clamped at high pressure by the clamping cylinder.
Wear. Conversely, a strong mold opening can also be performed.

Furthermore, the molding device according to the invention of claim 2
According to the arrangement, the unequal-speed driving hand using the oscillating cylinder as the driving source
The working fluid from the drive pump is swung by the stage
To swing the link mechanism.
Therefore, a drive source separate from the drive pump for the mold clamping cylinder
No need to provide.

The molding device according to the third aspect of the present invention.
According to the position, the lever that constitutes the link mechanism is
With the step, the length of the lever is adjusted by the length adjusting means.
By adjusting the mold clamping cylinder
Stroke can be adjusted.

According to the molding apparatus of the fourth aspect,
If the speed is gradually increased by the unequal speed drive, then gradually decreased
High-speed opening / closing pump operated at unequal speed
Supply working fluid to the tightening cylinder to open and close the mold at high speed
Can be made. Note that the unequal-speed driving means is
By rotating the crank mechanism by driving the source,
Accordingly, the high-speed opening / closing pump is caused to perform the unequal speed operation.
Then, the working fluid is supplied from the high-speed opening / closing pump.
This allows the mold clamping cylinder to operate at high speed.
You. Therefore, use a high pressure, low speed type clamping cylinder.
Complex equipment and speed control
Speeds up the opening and closing of the mold.
As a result, it is possible to achieve high efficiency by shortening the molding cycle.
it can. Also, the switching operation of the switching valve causes the drive pump to
The working fluid is supplied to the mold clamping cylinder and
The mold can be strongly clamped at a higher pressure. And vice versa
In addition, a powerful mold opening can also be performed.

Further, the molding device according to the invention of claim 5
According to the arrangement, unequal speed drive means using an electric motor as a drive source
Separate from the drive pump for the clamping cylinder
The crank mechanism can be rotated by the motor.
You.

The molding device according to the invention of claim 6
According to the arrangement, since the rotor constituting the crank mechanism is provided with a crank pin position adjusting means, the position of the crank pin is adjusted by the position adjusting means, so that the stroke of the mold clamping cylinder corresponding to a change in the mold thickness is obtained. Can be adjusted.

[Brief description of the drawings]

FIG. 1 shows an injection molding machine as an example of a molding device to which the present invention is applied, and includes a first main device including a hydraulic circuit.
FIG. 2 is a schematic configuration diagram showing an embodiment.

FIG. 2 is an enlarged configuration diagram of a mold clamping cylinder and a high-speed opening / closing pump portion of FIG. 1;

FIG. 3 is a diagram showing a relationship between components of the unequal-speed driving unit of FIG. 1;

FIG. 4 is a timing chart showing operation control of the main device of FIG. 1;

5 shows an injection molding machine as an example of a molding apparatus to which the present invention is applied, and is a schematic configuration diagram showing a second embodiment of a main device including a hydraulic circuit, similarly to FIG.

FIG. 6 is an enlarged view, partially broken away, showing the relationship between the high-speed opening / closing pump of FIG. 5 and the crank mechanism of the unequal-speed driving means.

FIG. 7 is a partially cutaway side view showing the relationship between the adjustment screw, the crankpin, and the arm from the direction of arrow A in FIG. 6;

8 is a diagram showing a state in which the high-speed opening / closing pump of FIG. 6 is operated by the crank mechanism of the unequal-speed driving means.

FIG. 9 is a timing chart showing operation control of the main device of FIG. 5;

[Explanation of symbols]

Reference Signs List 2 fixed mold 4 movable mold 6 mold clamping cylinder 11 plasticizing means 15 injection cylinder 21 drive pump 22 injection pump 31 high-speed opening / closing pump 34 unequal-speed drive means 35 link mechanism 36 arm 39 lever 41 swing cylinder 46 crank Mechanism 47 Arm 49 Crank pin 51 Rotor Mc Electric motor for driving high-speed opening / closing pump Mi Electric motor for driving injection pump Mp Electric motor for driving pump Psw Pressure switch T tank V ₁ , V ₂ , V ₃ , V _4, V ₅ electromagnetic switching valve Vbp back pressure control valve Vpp pressure control valve _{V A, V B, V C} , V D, V E check valve V _F relief valve W moldings

Claims (6)

(57) [Claims] 1. A molding apparatus comprising : a pair of molds forming a cavity; and a mold clamping cylinder for opening and closing the molds, wherein a driving pump for supplying a working fluid to the mold clamping cylinder; A high-speed opening / closing pump for supplying a working fluid to the cylinder to open and close the mold at a high speed; and a non-uniform speed driving for operating the high-speed opening / closing pump at a gradually increasing speed and then gradually reducing the speed. Means and the drive pump when strongly clamping the mold at high pressure.
Switch to supply the working fluid to the mold clamping cylinder
Comprising a control valve for work, the said non-uniform drive means, non-uniform in the high-speed opening and closing the pump
Link mechanism for exercise and swinging of this link mechanism
A molding source, comprising: 2. The apparatus according to claim 1 , wherein said drive source is operated by said drive pump.
Swing for taking in fluid and swinging the link mechanism
The molding device according to claim 1, wherein the molding device is a cylinder.
Place. 3. The link mechanism is connected to the drive source.
Between the lever and the high-speed opening / closing pump.
And an arm connecting the levers , and the lever is
2. The apparatus according to claim 1, further comprising a length adjusting means.
Or the molding apparatus according to 2. 4. A pair of molds forming a cavity,
A mold clamping unit for opening and closing a mold
And a driving pump for supplying a working fluid to the mold clamping cylinder, and supplying a working fluid to the mold clamping cylinder to speed up the mold.
High-speed on / off pump operated by open / close operation, and gradually increase and then gradually decelerate this high-speed on / off pump
Unequal-speed driving means for unequal-speed operation, and the drive pump for strongly clamping the mold at high pressure.
Switch to supply the working fluid to the mold clamping cylinder
Comprising a control valve for work, the said non-uniform drive means, said non-the fast opening and closing the pump
Crank mechanism for performing constant speed operation and this crank mechanism
And a driving source for rotating the motor.
Shaped device. 5. The driving source rotates the crank mechanism.
5. The electric motor according to claim 4, wherein the electric motor is operated.
On-board molding equipment. 6. The crank mechanism is rotated by the drive source.
The rotor that is driven to rotate and the clan installed on this rotor
Kupin, this crankpin and the high-speed opening / closing pump
And an arm connecting the crank pins , and the rotor is a means for adjusting the position of the crank pin.
The method according to claim 4 or 5, wherein
Molding equipment.