JPH0560108A - Cylinder device - Google Patents

Abstract

PURPOSE:To provide a monoblock cylinder device which is a long stroke cylinder and can conduct a quick stroke motion and continue to generate strong force in a stopped state. CONSTITUTION:A cylinder device is made of a cylinder case 1, a piston 2 and a sliding member 4 which are slidably inserted into the cylinder case 1 and form a pressure chamber 12 between them, a pressing part 3 provided at a tip of the rod of the piston 2, a threaded part 5 formed on the sliding member 4, a nut part 6 to be engaged with the threaded part 5 and a driving source 8 for turning the nut part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder device having a long stroke and capable of generating a large pressing force when a piston rod is stopped, and particularly to an injection molding machine and a press having a mold which can be opened and closed. The present invention relates to a cylinder device that is effectively used for such purposes.

[0002]

2. Description of the Related Art First, the opening / closing operation of a mold will be described with reference to FIG. Fixed plates 101, 1 on both sides
02 are connected by a tie rod 103,
A movable platen 104, which is guided by, is provided between the fixed plates 101 and 102. Then, the mold 105 is attached to the fixed plate 101.
Is attached to the movable platen 104, and the mold 106 is attached to the movable plate 104, and a molded product having a predetermined shape is molded between the molds 105 and 106. When taking out the molded product, both molds 105,
106 needs to be wide open, and the movable platen 104 is moved to the fixed platen 102 side. When this movement is performed by the hydraulic cylinder, the stroke is long, and a relatively high speed is required to improve the cycle time, and the force amount may be significantly smaller than the mold clamping force described below. Further, when the movable platen 104 is moved by two or more hydraulic cylinders, a predetermined moving speed is required to maintain the parallelism and the squareness of the movable plate 104. During molding of the molded product, both molds 105 and 106 are closed and clamped so as to withstand the molding pressure due to the injection of the high-pressure molten resin. When this mold clamping force is generated by the hydraulic cylinder, a large diameter hydraulic cylinder is required.

As described above, the characteristics required for the hydraulic cylinder for opening and closing the mold and the hydraulic cylinder for clamping the mold are very different. Therefore, as shown in FIG. 7, the hydraulic cylinder 107 for opening and closing the mold and the hydraulic cylinder 1 for clamping the mold.
08 and two types of hydraulic cylinders are used. In this case, since there is a distance between the hydraulic cylinder 108 and the fixed plate 102, the extension rod 109 is connected to the hydraulic cylinder 108 and the lock device 110 that meshes with the screw 109 a of the extension rod 109.
Caused the mold clamping force.

[0004]

As described in the prior art, it is necessary to use two types of hydraulic cylinders for opening and closing the mold. Also, a hydraulic cylinder 1 for opening and closing the mold
Since 07 requires a high stroke speed, a large flow rate hydraulic pump is required, and a considerably large hydraulic unit is required. However, in the hydraulic cylinder 108 for mold clamping,
The flow rate is small, but large pressure is required. Therefore, there is a problem that a large capacity hydraulic unit is required by using two pumps.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to provide a long stroke cylinder, which has a long stroke and a large force when stopped. It is intended to provide a single cylinder device that can continue to occur.

[0006]

In order to achieve the above object, a cylinder device according to the present invention comprises a cylinder case, a piston slidably inserted into the cylinder case and forming a pressure chamber therebetween. A sliding member, a pressing portion at the tip of the rod of the piston, a screw portion formed on the sliding member, a nut portion screwed to the screw portion, and a drive source for rotating the nut member. To do. And it is preferable to provide a space limiting means between the piston and the sliding member. Also, as the cylinder device of the previous term, a rod is provided between the piston and the sliding member, one of which is fixed to the piston side and the other of which is connected to the sliding member with a spring member having play that can be restored. It is also possible to provide a detector that detects a relative positional change between the sliding member and the rod due to the play.

Further, as another cylinder device, a cylinder case, a first piston and a second piston which are slidably inserted into the cylinder case to form a pressure chamber therebetween, and a rod tip of the first piston And a clamp means attached to the cylinder case so as to fix the rod of the second piston.

[0008]

In the cylinder device according to the present invention, a small and large amount of force when opening and closing the die is used to perform a fast and long stroke by means of the screw portion and the screw portion driving device formed on the sliding member, and the die clamping is performed with a small capacity and high pressure oil. Is introduced into the pressure chamber and the piston is driven, and these are combined into one device. Further, when there is a risk that the pressure oil will escape due to piping leakage or the like and the piston will expand due to its own weight or the like, the interval limiting means between the piston and the sliding member locks the expansion beyond a slight stroke. When the piston reaches the stroke end, the rod moves relative to the sliding member, and when the detector detects this movement, the stroke is stopped.

In another cylinder device, a second piston is used to perform a fast and long stroke with a small amount of force when opening and closing the die, and the second piston is clamped by clamping the second piston with a small volume of high pressure oil. It is carried out by introducing it into the pressure chamber and driving the first piston, and these are combined into one device.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view of a cylinder device of the present invention, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is a sectional view taken along line 3-3 of FIG.

1 and 2, 1 is a cylinder case, 2 is a piston, 3 is a pressing portion, 4 is a sliding member, 5 is a screw portion, 6 is a nut portion, 7 is a drive gear, 8 is a motor, and 9 is a motor. ，
10 is a gear case, 11 is a mounting portion, 12 is a pressure chamber, 13
Is a screw drive device.

A seal member 2 is provided in the cylinder case 1 of FIG.
A piston 2 having 1 is slidably inserted. Further, the sliding member 4 having the seal member 22 is also slidably inserted in the cylinder case 1. A pressure chamber 12 is formed between the piston 2 and the sliding member 4,
The piston 2 descends as pressure oil is introduced into the pressure chamber 12 through the oil passage 23 in the piston 2. The tip of the piston 2 is a flange-shaped pressing portion 3,
For example, it is connected to the movable plate 104 in FIG. In addition, 24 is a bellows. Further, the oil passage 23 can be provided in the screw portion 5 of the sliding member 4 described below.

A screw portion 5 is provided on a portion of the sliding member 4 corresponding to the rod.
Are formed. The screw portion 5 can be housed in the cylindrical body 10a of the gear case 10, and the key 25 attached to the tip is guided by the key groove 26 of the cylindrical body 10a to regulate the rotation. A nut portion 6 is screwed into the screw portion 5, and a bearing 27, between a gear case 9 formed as an extension member of the cylinder case 1 and a gear case 10 which is a separate member.
The nut portion 6 is rotatably supported via 28.
Further, the drive gear 7 is fitted into the output shaft of the motor 8 attached to the gear case 9 and meshes with the nut portion 6 (see FIG. 3). A pulse generator 29 is attached to the motor 8 so that the axial movement amount of the screw portion 5 via the drive gear 7 and the nut portion 6 can be controlled. The above-mentioned gear cases 9 and 10, the nut portion 6, the drive gear 7, and the motor constitute a screw portion drive device 13. A trapezoidal screw is exemplified as the screw portion 5, and this trapezoidal screw is preferable because the friction angle is large and the nut portion 6 does not rotate due to an axial force. However, other sawtooth screws, ball screws, etc. can be used. However, in the case of a ball screw, the nut tends to rotate due to the axial force, and therefore it is necessary to provide the motor 8 with a brake. Further, as a drive source for the screw portion 5 and the nut member 6, a spur gear and a speed reducer motor 8 are provided.
However, various gears such as a worm gear, a combination of a chain drive or a belt drive and a hydraulic motor, and the like can be used.

A gear case 9 formed as an extension member of the cylinder case 1 and a gear case 10 which is a separate member are bolts 3.
0 is integrated, and the end surface portion of the gear case 10 is a flange-shaped mounting portion 11. The mounting portion 11 is coupled to, for example, the fixing plate 102 shown in FIG. In addition, mounting part 1
1 is not limited to being provided in the screw portion drive device 13, but may be provided in the cylinder case 1 as shown by the chain double-dashed line.
Further, the mounting portion is not limited to the flange shape and may be a trunnion type mounting portion.

The bolt 31 is screwed into the piston 2, the head of the bolt 31 contacts the bottom surface of the recess 32 of the sliding member 4, and the piston 2 also moves in the D direction as the sliding member 4 moves in the C direction. A stopper 33 and a disc spring 34 are housed in the recess 32 via a pressing plate 35 to urge the head of the bolt 31 to the illustrated state and limit the stroke to the distance ε. That is, the bolt 31, the disc spring 34, and the like serve as a space limiting means between the piston 2 and the sliding member 4.

Next, the operation of the cylinder device having the above structure will be described with reference to FIG. For example, it is assumed that the mounting portion 11 is bolted to an upper fixing plate such as a press and the pressing portion 3 is bolted to an upper die. In this case, the disc spring 34 has a biasing force capable of supporting the upper mold. First, to close the upper mold and the lower mold,
The motor 8 rotates a predetermined amount by the pulse generator 29 (the brake 8a prevents overrun). The drive gear 7 and the nut portion 6 rotate, the screw portion 5 guided by the key 25 descends, and the piston 2 moves with the sliding member 4 for a predetermined distance. That is, the upper die fixed to the pressing portion 3 of the piston 2 by the bolt descends by a predetermined distance and comes into contact with the lower die. The stroke of the piston 2 by a predetermined amount may stop the motor 8 by detecting the position with a limit switch or the like. When the motor 8 stops, the nut portion 6 also stops, and the friction of the screw causes the screw portion 5 to remain at the predetermined position as it is.

Then, pressure oil from a separately provided hydraulic unit (not shown) is guided to the pressure chamber 12 through the hydraulic pressure inlet 36 and the oil passage 23 on the side surface of the pressing portion 3. As a result, the piston 2 overcomes the biasing force of the disc spring 34, makes a short stroke within the distance ε, and the pressing force acts between the upper and lower molds. The reaction force of this pressing force also acts on the screw portion 5 of the sliding member 4, but this reaction force is applied to the nut portion 6
It acts on the lower surface of the mounting portion 11 through the surface of (1) and is sufficiently supported. Further, even if the hydraulic pressure is released during the pressurization for some reason, the bolt 2 and the like act as the interval limiting means, so that the piston 2 is lowered only slightly within the distance ε, which is safe. The capacity of the pressure chamber 12 is small, and the hydraulic unit may be suitable for it. Further, since the descending position of the sliding member 4 is accurately controlled by the motor 8, even when a plurality of cylinder devices are used, the sliding member 4 can be raised and lowered while reliably maintaining the levelness. The lower portion of the cylinder case 1 is thicker because the pressure chamber 12 moves downward and is pressurized. Further, the usage example of the cylinder device is not limited to the vertical orientation, but can be used in the horizontal orientation. Further, not only hydraulic pressure but also pneumatic pressure may be used.

Next, another embodiment will be described with reference to FIG. The difference from FIG. 1 is that the lower end of the rod 41 is screwed into the piston 2, the head 42 of the rod 41 projects from the upper surface of the sliding member 4, and the disc spring 42 is wound around the rod of the pressure chamber 12. That is the point.

The lower end of the rod 41 is threaded and screwed into the piston 2, whereby the rod 41 and the piston 2 are fixed. On the other hand, the rod 41 is slidably pierced by a packing so as to prevent oil in the pressure chamber 12 from entering the sliding member 4, and its head 42 is formed larger than the diameter of the rod 41. And is projected to the upper surface of the sliding member 4. The disc spring 43 fitted into the rod 41 in the pressure chamber 12 is driven by the motor 8 to rotate the drive gear 7.
Also, the sliding member 4 descending by the nut portion 6 urges the piston 2 side to lower the piston 2 while keeping the space E between the pressure chambers constant, and the upper and lower dies come into contact with each other to lower the piston 2. When stopped, it acts as a preload. Further, a limit switch 44 as a detector is attached to the upper surface of the sliding member 4, and the head portion 42 of the rod 41 further protrudes with respect to the sliding member 4, whereby O
FF is done.

Next, the operation of the above cylinder device will be described. When the motor 8 operates and the sliding member 4 descends, the piston 2 descends while the interval E between the pressure chambers 12 is kept constant by the urging force of the disc spring 43. When the upper mold, which is bolted to the pressing portion 3 of the piston 2, descends for a predetermined distance and comes into contact with the lower mold, the piston 2 can no longer descend, and the piston 2 rides on the mold. Stop in the closed state. Nevertheless, since the sliding member 4 overcomes the biasing force of the disc spring 43 and further descends, the interval E is narrowed and the rod 4
1 has its lower end pushed up by the piston 2 and moves up in the sliding member 4. Therefore, the head 42 of the rod 41 projects further upward than the illustrated state, so that the limit switch attached to the upper surface of the sliding member 4 is operated and the motor 8 is turned off. Stops. As a result, when the height of the mold is changed, the rotation speed of the motor 8 is changed one by one to convert the descending distance of the piston 2 to determine the lower limit position of the stroke. ..

Then, pressure oil from a separately provided hydraulic unit (not shown) is guided to the pressure chamber 12 through the hydraulic pressure inlet 36 and the oil passage 23 on the side surface of the pressing portion 3. At this time, even if the hydraulic pressure is released during pressurization for some reason, since the head portion 42 is formed larger than the diameter of the rod 41, it supports the piston 2 to prevent it from descending, which is safe. That is, the rod 41 and the like act as the interval limiting means. Further, the usage example of the cylinder device is not limited to the vertical orientation, but can be used in the horizontal orientation. Further, not only hydraulic pressure but also pneumatic pressure may be used.

Next, the motor 8 is rotated in the reverse direction to move the sliding member 4
Is raised, the head portion 42 of the rod 41 and the disc spring 43 are restored to their original positions, and the piston 2 is also raised by being caught by the rod 41. In this way, the lower end of the rod 41 is fixed to the piston 2, and the sliding member 4 and the rod 41 are connected with each other by a spring member having play that can be restored. The limit switch 44 is operated by the relative position change.

FIG. 5 does not have the interval limiting means by the bolt 31 of FIG. 1, and the sliding member 4 and the piston 3 can be separated. The bolt 37 merely contacts the pressing plate 38, and the bolt 37 pushes down the piston 3 when the sliding member 4 descends. In this case, in order to return the piston 3, the pressure chamber 14 facing the pressure chamber 12 is provided and the piston 3 is moved back. Since the force for returning may be small, the pressure receiving area of the pressure chamber 14 can be made small and a large stroke can be made with a small amount of oil. When the sliding member 4 descends, the oil in the pressure chamber 14 is discharged from the hydraulic pressure inlet 39. When the sliding member 4 is moved up, the sliding member 4 is moved up first, and then the hydraulic pressure is introduced into the hydraulic pressure introducing port 39, or the hydraulic pressure introducing port 3 is moved up when the sliding member 4 is raised.
Apply hydraulic pressure from 9 and raise simultaneously. In this way, by making the piston 3 double-acting, it becomes possible to cope with various usage examples. Even if the piston 3 is not double-acted, the hydraulic passage 2
When 3 is closed, the pressure chamber 14 becomes a negative pressure when the sliding member 4 moves up, so that the piston 3 moves up together with the sliding member 4.

Next, another cylinder device will be described with reference to FIG. The piston 2 is slidably inserted into the cylinder case 1, the tip of the piston 2 serves as the pressing portion 3, and the pressure chamber 1
The points 2 and 14 are the same as in FIG. However, the double-acting second piston 15 having the pressure chamber 16 instead of the sliding portion of FIG.
4 is different from FIG. 4 in that a bare lock 18 as a clamping means for 7 is fixed to the cylinder case 1. That is, by the pressure chamber 14 of the first piston 2 and the pressure chamber 16 of the second piston 15, which have small pressure receiving areas, respectively, the first piston 2 and the second piston 15 can move up and down to arbitrary positions while interlocking. Then, the rod 17 of the second piston 15 is fixed at a predetermined position by the bare lock 18, and a large pressure is generated in the pressure chamber 12. The reaction force of the applied pressure is received by the cylinder case 1 via the bare lock 18. The bear lock 18 is of a type in which the wall surface 18b is expanded by the introduction of hydraulic pressure into the pressure chamber 18a and holds the rod 17. The cylinder device may also be provided with the interval limiting means shown in FIG. If provided, the first piston 2 may be single acting.

[0025]

In the cylinder device according to the present invention, a small and large amount of force at the time of opening and closing the mold is used to perform a fast and long stroke by the screw part and the screw part driving device formed on the sliding member, and the mold clamping is performed with a small capacity and a high pressure. The pressure oil is introduced into the pressure chamber to drive the piston, or the second piston is used for a fast and long stroke with a small amount of force when opening and closing the mold, and the second piston is clamped for clamping the mold. This is done by introducing a small amount of high pressure oil into the pressure chamber and driving the first piston, and since these are combined in one device, even a cylinder with a long stroke will travel quickly,
It is a single device that can continue to generate a large amount of power when stopped. Since it is a single device, it can be mass-produced and its application range can be expanded at a low price. Further, when the space limiting means between the piston and the sliding member is provided, if the pressure oil may escape due to piping leakage or the like and the piston may expand due to its own weight or the like, the expansion is locked and it is safe. Further, if a rod and a limit switch as a detector are provided, the piston naturally stops at the stroke end when the upper and lower molds come into contact with each other, so that no complicated positioning adjustment is required when changing the height of the mold. Furthermore, in the combination of the piston and the adjusting screw of the sliding member, since they are inserted in the same cylinder case, mutual misalignment does not occur, and stable operation is secured.

Such a cylinder device is suitable for various applications requiring two or more of the following requirements. Does not require too much force during the stroke. The speed during the stroke is relatively fast. During the stroke, the stroke is accurate at a predetermined speed. A large force is required at a predetermined position such as the stroke end and at an arbitrary position, and it may be a short stroke like mold clamping. A large amount of force is required from the middle of the stroke like a plate bending press. At any position during pressurization, the piston should not largely escape due to oil leakage from packing, piping joint, switching valve, etc. or pressurization of piping during pressurization. The piston does not drop even if the pressure oil escapes. Therefore, many examples of use are conceivable without being limited to the illustrated injection molding machine and press.

[Brief description of drawings]

FIG. 1 is a sectional view of a cylinder device of the present invention.

FIG. 2 is a view taken along line 2-2 of FIG.

3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is a cross-sectional view of another cylinder device of the present invention.

FIG. 5 is a cross-sectional view of another cylinder device of the present invention.

FIG. 6 is a cross-sectional view of another cylinder device of the present invention.

FIG. 7 is a partial cross-sectional view of a mold clamping device using a conventional cylinder device.

[Explanation of symbols]

 1 Cylinder Case 2 Piston 3 Pressing Part 4 Sliding Member 5 Screw Part 8 Motor (Drive Source) 11 Mounting Part 12 Pressure Chamber 13 Screw Part Drive Device 15 Second Piston 18 Bare Lock (Clamping Means) 41 Rod 42 Rod Head 43 Disc spring 44 limit switch

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[Procedure amendment]

[Submission date] April 22, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

Then, pressure oil from a separately provided hydraulic unit (not shown) is guided to the pressure chamber 12 through the hydraulic pressure inlet 36 and the oil passage 23 on the side surface of the pressing portion 3. As a result, the piston 2 overcomes the biasing force of the disc spring 34, makes a short stroke within the distance ε, and the pressing force acts between the upper and lower molds. The reaction force of this applied pressure also acts on the screw portion 5 of the sliding member 4, but this reaction force is applied to the nut portion 6
It acts on the lower surface of the mounting portion 11 through the surface of (1) and is sufficiently supported. Further, even if the hydraulic pressure is released during the pressurization for some reason, the bolt 2 and the like act as the interval limiting means, so that the piston 2 is lowered only slightly within the distance ε, which is safe. The capacity of the pressure chamber 12 is small, and the hydraulic unit may be suitable for it. Further, since the descending position of the sliding member 4 is accurately controlled by the motor 8, even when a plurality of cylinder devices are used, the sliding member 4 can be raised and lowered while reliably maintaining the levelness. The lower portion of the cylinder case 1 is thicker because the pressure chamber 12 moves downward and is pressurized. Further, the usage example of the cylinder device is not limited to the vertical orientation, but can be used in the horizontal orientation. Further, not only hydraulic pressure but also pneumatic pressure may be used. In addition, the mold in advance
This adjustment is made with the adjustment screw height adapted to the thickness of
Pressure is applied to only the hydraulic cylinder every cycle.
It is also possible to drive the car in a way that allows it.

Claims (4)

[Claims] 1. A cylinder case, a piston and a sliding member that are slidably inserted into the cylinder case to form a pressure chamber therebetween, a pressing portion at a rod tip of the piston, and a sliding member. A cylinder device comprising: a threaded portion, a nut portion that is screwed into the threaded portion, and a drive source that rotates the nut member. 2. The cylinder device according to claim 1,
A cylinder device characterized in that a gap limiting means is provided between the piston and the sliding member. 3. The cylinder device according to claim 1, wherein
A rod is provided between the piston and the sliding member, one of which is fixed to the piston side and the other of which is connected to the sliding member by a spring member having play that can be restored, A cylinder device provided with a detector for detecting a relative position change with a rod. 4. A cylinder case and a first chamber slidably inserted into the cylinder case to form a pressure chamber therebetween.
A cylinder device comprising a piston and a second piston, a pressing portion at a rod tip of the first piston, and a clamp means attached to a cylinder case so as to grip the rod of the second piston.