JP3655042B2 - Sealed hydraulic pressure booster - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hermetic hydraulic pressure booster, and more particularly to a hermetic hydraulic pressure booster that is driven and controlled by a servo motor and can be effectively applied as a mold clamping device such as an injection molding machine.
[0002]
[Prior art]
Conventionally, in a mold clamping device such as an injection molding machine, the mold is opened and closed with a fixed plate by moving a moving plate, and the mold is pressed with a large force against the injection resin pressure. A function to tighten is required. As such a mold clamping device, conventionally, a boost ram system in which a boost ram is inserted into a mold clamping ram inserted and arranged in the mold clamping cylinder, and a side cylinder system in which a plurality of side cylinders are installed separately from the mold clamping cylinder. Alternatively, a mechanism such as a pressure-increasing cylinder system in which a mold-clamping cylinder and a pressure-increasing cylinder are arranged in series is configured to open and close the mold at a high speed and perform mold clamping at a high pressure. Direct pressure type clamping devices are widely used.
[0003]
However, the conventional direct pressure type mold clamping apparatus needs to be provided with a complicated hydraulic circuit in order to open and close the mold at a high speed and obtain a sufficient mold clamping force, and further supplies the mold clamping cylinder and the like. It is necessary to provide an oil tank or the like for storing pressure oil, and in particular, in the boost ram type and side cylinder type described above, it is necessary to employ a high pressure pump in order to obtain a high mold clamping force. In the pressure-increasing cylinder type, the length of the device is increased.
[0004]
From this point of view, the first double-action cylinder is provided with first and second hydraulic pressure chambers whose volumes increase or decrease by the same amount as the double-action ram moves, and the double-action ram moves with the moving plate. A pump that is rotationally driven by the first driving device is provided in the hydraulic fluid passage that connects the first hydraulic chamber and the second hydraulic chamber, and the pump and the first and second hydraulic chambers The first and second hydraulic chambers are connected to the pump, and the first and second hydraulic chambers are connected to the pump, and the first and second hydraulic chambers are disconnected from the pump. the switching valve device is provided, the second having a first and second booster chamber which volume with the movement of the double-acting piston communicates only increased or decreased and the first and second hydraulic chambers respectively the same amount A double-acting cylinder is provided, and the nut member and the nut member are assembled with a predetermined screw structure. And one of these members is connected to the double-acting piston, and the other member is driven to rotate in both the forward and reverse directions by the second drive device to reciprocate the double-acting piston. A mold clamping device in an injection molding machine provided with a screw mechanism has been proposed (Japanese Patent Publication No. 1-178551).
[0005]
That is, the mold clamping device having the above-described structure operates the first double-acting cylinder to open and close the mold by the rotation of the pump in the communication state of the switching valve device, while the screw in the cutoff state of the switching valve device. The mold is clamped by operating the second double-acting cylinder by rotation of the mechanism.
[0006]
Therefore, the mold clamping device configured in this manner allows the hydraulic fluid filled in the first and second hydraulic pressure chambers and the hydraulic fluid passage to flow by the pump when the mold is opened and closed. Since the double-action ram is configured to move forward and backward, it is possible to obtain an advantage that it is not necessary to provide a tank or the like for storing pressurized liquid outside.
[0007]
Further, conventionally, a mold clamping device configured to reciprocate a moving plate by a screw feeding mechanism driven by, for example, an AC servo motor is also known. In this type of mold clamping device, in order to obtain a sufficient mold clamping force, it is inevitable to increase the size of a screw feed mechanism or the like for transmitting the mold clamping force to the moving plate including the servo motor. In particular, in the type in which a hydraulic device is used in combination with a servo motor, a large clamping force can be obtained. However, equipment such as a hydraulic pump, a hydraulic circuit, and the like are required, and there is a problem that the device becomes complicated.
[0008]
Therefore, from this point of view, one end of the male screw rod is screwed into the inner hole of the nut member rotated by the servo motor, and the male screw rod can be moved straight by rotation of the nut member. A hydraulic operating plate that is engaged and moved by being guided by the tie bar so as to create a gap with the moving plate is provided adjacently, and the moving plate is moved by engaging the tip of the male screw rod with the hydraulic operating plate. When the moving plate is moved forward and the mold is closed, a hydraulic operation panel position fixing means for fixing the hydraulic operation panel by engaging the hydraulic operation panel with a groove provided on the outer periphery of the tie bar is provided. The hydraulic operation panel has a built-in sealed bag filled with liquid, and is provided with a piston for generating a clamping force on the moving plate by being displaced by the increased pressure of the sealed liquid in the sealed bag. After being fixed to the tie bar There has been proposed a mold clamping device of an injection molding machine having a configuration in which a buffer member is provided in which the sealing bag is pressed against the male screw thread by the advancement of the screw thread so as to apply a mold clamping force to the piston. Kaihei 6-246806).
[0009]
In other words, the mold clamping device having the above-described structure presses and compresses the sealed liquid in the sealed bag with the male screw rod, and causes the pressure of the sealed liquid increased thereby to act as a mold clamping force. A sufficient clamping force can be obtained by applying a slight pressing force, and the advantage that the servo motor as a drive source and the screw feed mechanism for transmitting the force of the servo motor can be reduced in size can be obtained. is there.
[0010]
[Problems to be solved by the invention]
However, the aforementioned pressure increasing mechanism of the conventional mold clamping device has the following problems to be improved.
[0011]
That is, the former pressure increasing mechanism of the mold clamping device configured to open and close the mold and clamp the mold by operating the double acting cylinder by the rotation of the screw mechanism has the same volume as the double acting ram moves. Two hydraulic chambers that increase or decrease by the amount are provided, and two additional pressure chambers are provided. By switching the switching valve, the mold is opened and closed by the flow of the hydraulic fluid by the pump, and the screw The mold is clamped by the rotation of the mechanism, so that the structure and control operation are complicated, the manufacturing cost is increased, and there is a problem that pressure fluid leaks and noise is generated.
[0012]
Further, the pressure-increasing mechanism of the mold-clamping device configured to generate a mold-clamping force by increasing the pressure of the sealed liquid in the airtight bag by pressing and displacing the airtight bag in which the liquid is sealed by the latter hydraulic pressure operation panel. Although there is an advantage that contributes to downsizing of the device, there are many restrictions on the manufacture of a sealed bag enclosing a liquid and the manufacture of a displacement transmission mechanism for obtaining a sufficient pressing force. The manufacturing cost also increases.
[0013]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sealed hydraulic pressure intensifier that can be configured in a simple and compact manner, prevents liquid leakage and noise, and can be widely applied as various pressure intensifiers. There is.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, a sealed hydraulic pressure booster according to the present invention includes a piston portion of a piston rod that is hermetically housed in a cylinder fluid chamber of a sealed hydraulic cylinder and is disposed adjacent to the cylinder fluid chamber. In the hermetic hydraulic pressure booster configured to control the hydraulic pressure in the cylinder fluid chamber by the unit and obtain an increased output from the piston rod,
A fluid passage that communicates between the cylinder fluid chamber and the pressure increase control unit is provided, and a compression member configured to be moved forward and backward by a servo motor is inserted and disposed in the fluid passage, and the fluid pressure or piston generated in the cylinder fluid chamber A pressure sensor for detecting an output obtained from the rod is provided, and the servo motor is controlled so that the pressure detected by the pressure sensor maintains a preset pressure.
[0015]
In this case, the liquid passage that communicates the cylinder liquid chamber and the pressure increase control unit may be arranged parallel to the axis of the piston rod.
[0016]
In addition, the liquid passage that communicates the cylinder fluid chamber and the pressure increase control unit is formed by extending an orthogonal liquid passage that intersects perpendicularly and communicates with a liquid passage that is disposed in parallel to the axial center of the piston rod. It can be set as the structure which consists of a structure and the compression member comprised so that advancing and retreating movement with a servomotor was inserted and arranged with respect to this orthogonal liquid channel | path.
[0017]
On the other hand, the pressure increase control unit transmits the rotational drive of the servo motor to the rotating nut through the connecting unit, and advances the compression member together with the feed screw screwed with the rotating nut by the rotation of the rotating nut. The interior of the chamber can be increased to obtain a predetermined output from the piston rod.
[0018]
Further, the pressure increase control unit holds the feed screw coupled to the compression member by a rotating nut, and rotatably attaches the rotating nut, and attaches the rotor core of the servo motor to the outer periphery of the rotating nut. A stator coil of the servo motor is disposed so as to surround the rotor core, and the rotary nut is integrally rotated with the rotor core of the servo motor so that the compression member can be moved forward together with the feed screw.
[0019]
Further, the sealed hydraulic cylinder is provided with a seal member at a contact portion between the piston rod and its piston portion and a contact portion between the cylinder fluid chamber and the compression member in the fluid passage communicating with the pressure increase control portion. Can.
[0020]
The sealed hydraulic cylinder is provided with a seal member at a contact portion with the piston rod and a contact portion with the compression member in the fluid passage communicating the cylinder fluid chamber and the pressure increase control portion. The piston portion is provided with a communication hole that communicates the pressure increasing chamber side and the back pressure chamber side of the cylinder fluid chamber, and the increased pressure output from the piston rod corresponds to the cross section of the cylinder fluid chamber. It may be Rukoto as obtained based on the difference of the liquid pressure acting area of the booster chamber side and the back pressure chamber side.
[0021]
Therefore, according to the hermetic hydraulic pressure intensifier of the present invention, the structure is simple and downsized, the degree of design freedom such as shape and capacity is expanded, and the leakage of pressure liquid and the generation of noise are prevented. be able to.
[0022]
【Example】
Next, an embodiment of a hermetic hydraulic pressure booster according to the present invention will be described in detail with reference to the accompanying drawings.
[0023]
Example 1
FIG. 1 shows an embodiment of a sealed hydraulic pressure booster according to the present invention. That is, the hermetic hydraulic pressure booster shown in FIG. 1 basically includes a hermetic hydraulic cylinder 10 and a pressure increase control unit 12, and the piston rod 16 is placed in the cylinder fluid chamber 14 of the hermetic hydraulic cylinder 10. The piston portion 16a is hermetically housed, and the pressure in the cylinder fluid chamber 14 is controlled by the pressure-increasing control unit 12 disposed adjacent to the cylinder fluid chamber 14 to obtain an increased output from the piston rod 16. It is configured.
[0024]
However, a fluid passage 18 disposed coaxially with the axial center of the piston rod 16 is provided in the communicating portion between the cylinder fluid chamber 14 and the pressure increase control portion 12, and the fluid passage 18 is advanced and retracted by a servo motor 20 described later. A compression member 22 configured to be movable is inserted and arranged. In this case, the compression member 22 is coaxially coupled to a feed screw 24 that moves forward and backward by rotational drive, and the feed screw 24 has a rotating nut 26 that is screwed and held via a connecting portion 28. It is configured to be coupled to the output shaft 21 of the servo motor 20. In the connecting portion 28, a spline groove is formed in the feed screw 24 and the output shaft 21, and the rotational force is transmitted to the feed screw 24 by engaging with the spline groove. Further, the feed screw 24 moves forward and backward in cooperation with the rotary nut 26.
[0025]
On the other hand, in the cylinder fluid chamber 14, the return action spring member 30 after the pressure increase from the piston rod 16 disappears is disposed on the back pressure side of the piston portion 16 a, and the fluid pressure Pr generated in the cylinder fluid chamber 14. Alternatively, a pressure sensor 32 for indirectly detecting the output Pf obtained from the piston rod 16 is provided. The pressure sensor 32 detects the air pressure in the space where the spring member 30 is disposed, for example. Then, a detection signal of the pressure sensor 32 is sent to the drive control unit 34 of the servo motor 20 so as to control the servo motor 20 so that the pressure detected by the pressure sensor 32 maintains a preset pressure. Configure as follows.
[0026]
In FIG. 1, reference numeral 36 denotes a sealing member made of an O-ring or the like provided at an appropriate position in order to keep the cylinder liquid chamber 14 in a liquid-tight manner.
[0027]
The pressure sensor 32 may be integrated with the spring member 30 and replaced with a load meter that converts a spring deformation into a load.
[0028]
Therefore, according to the sealed hydraulic pressure booster of this embodiment configured as described above, the pressure boosting control unit 12 is configured to be driven by the dedicated servo motor 20, and the cylinder fluid chamber 14 is formed by the seal member 36. The structure is simple and compact because it has a simple and sealed independent structure, and can move the feed screw 24 forward and backward to the liquid passage 18 to obtain an output always kept at a predetermined value from the piston rod 16. As a result, the degree of freedom in designing the shape, capacity, etc. is expanded, and leakage of pressure fluid, generation of noise, and the like can be suppressed as much as possible.
[0029]
In the present embodiment, the liquid passage 18 is arranged in parallel with the axial center of the piston rod 16, but since the boosted output can be obtained evenly over the entire piston rod 16, the liquid passage 18 is arranged in a position parallel to the shaft core without any trouble. be able to.
[0030]
Example 2
FIG. 2 shows another embodiment of the sealed hydraulic pressure booster according to the present invention. The pressure booster in the present embodiment is obtained by changing the configuration of the liquid passage 18 in the embodiment shown in FIG. Therefore, the same components as those of the embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0031]
That is, the pressure boosting device of the present embodiment has a configuration in which an orthogonal liquid passage 18a that extends perpendicularly to and communicates with the liquid passage 18 that is coaxial with the piston rod 16 shown in FIG. A compression member 22 configured to be moved forward and backward by a servo motor 20 with respect to the orthogonal liquid passage 18a is inserted and arranged.
[0032]
Therefore, according to the pressure boosting device of the present embodiment having such a configuration, the pressure boosting control unit 12 is compared with the first embodiment in which the pressure boosting control unit 12 is arranged coaxially with respect to the piston rod 16. It can be provided on the side of the sealed hydraulic cylinder 10, thereby greatly reducing the dimension L in the displacement direction of the pressure increasing device, and the advantage of facilitating the setting for incorporation into various devices is obtained. It is done.
[0033]
Example 3
3 and 4 show still another embodiment of the sealed hydraulic pressure booster according to the present invention. In the pressure increasing device in the present embodiment, the internal structure of the pressure increasing control portion 12 is modified in the pressure increasing control portion 12 that drives the compression member 22 in the first embodiment shown in FIG. It consists of a structure.
[0034]
Specifically, as shown in FIG. 4 in particular, the pressure booster of this embodiment is configured so that the feed screw 24 and the spline member 23 that are coaxially coupled to the compression member 22 are screwed in the configuration of the pressure boost control unit 12. The rotating nuts 26 to be held together are rotatably arranged in the casing of the pressure increasing control unit 12 via bearings 27, respectively, and the rotor core 20a of the servo motor 20 is integrally formed on the outer periphery of the rotating nut 26, Further, a stator coil 20b of the servo motor 20 is installed in the casing of the pressure increase control unit 12 so as to surround the rotor, and the rotary nut 26 is rotated and driven integrally with the rotor core 20a of the servo motor 20. It is configured.
[0035]
Therefore, according to the pressure intensifying device of this embodiment having such a configuration, as shown in FIG. 3, the dimension L ′ in the displacement direction of the pressure intensifying device can be greatly reduced, and incorporated in various devices. The advantage that the setting can be facilitated is obtained.
[0036]
Example 4
FIG. 5 shows still another embodiment of the hermetic hydraulic pressure booster according to the present invention. The pressure booster in the present embodiment is a modification of the configuration of the piston rod 16 in the cylinder fluid chamber 14 of the sealed hydraulic cylinder 10 in the second embodiment shown in FIG.
[0037]
That is, the pressure increasing device of the present embodiment is configured such that the fluid pressure Pr is provided on the back pressure chamber side and the communication hole 38 communicating with the piston portion 16a of the piston rod 16 between the pressure increasing chamber side and the back pressure chamber side. Compared with the second embodiment shown in FIG. 2, the pressure sensor 32 is directly detected, and the spring member 30 is omitted, and the seal member 36 in the piston portion 16 a is omitted, and the configuration is simplified. It is. In this case, as shown in FIG. 5, the pressure increasing chamber communicating with the liquid passage 18 on the left side of the cylinder fluid chamber 14 and the back pressure chamber on the right side have the same pressure through the communication hole 38. The acting area is larger in the pressure increasing chamber on the left side by the cross-sectional area of the piston rod 16. Therefore, the piston rod 16 is driven to increase pressure to the right in the figure by the hydraulic pressure introduced to the pressure increasing chamber side.
[0038]
Application example 1
FIG. 6 shows an applied embodiment in which the hermetic hydraulic pressure booster 40 according to the present invention is applied to a mold clamping device 42 of an injection molding machine.
[0039]
That is, in this embodiment, the mold clamping device 42 is disposed so that the movable plate 52 attached with the movable die 50 via the tie bar 48 is opposed to the fixed plate 46 attached with the fixed die 44 so as to be movable forward and backward. Further, a connecting plate 54 is disposed behind the moving plate 52 via a tie bar 48, and the pressure increasing device 40 is attached between the moving plate 52 and the connecting plate 54. In this case, as the pressure intensifier 40, for example, the above-described sealed hydraulic pressure intensifier (FIG. 2) according to the second embodiment can be suitably used.
[0040]
The connecting plate 54 is configured to be capable of moving forward and backward through a piston rod 58 of a moving cylinder 56 fixed to the fixed plate 46, and a half of the connecting plate 54 that meshes with the threaded portion 48 a of the tie bar 48. A nut 60 and an operation cylinder 62 for driving the half nut 60 are appropriately provided. In FIG. 6, reference numeral 64 indicates a nozzle portion of an injection molding machine.
[0041]
In the mold clamping apparatus 42 of this embodiment configured as described above, first, the connecting plate 54 and the moving plate 52 are moved forward relative to the fixed plate 46 by the moving cylinder 56. Next, immediately before the movable mold 50 comes into contact with the fixed mold 44, the operating cylinder 62 is driven to engage the half nut 60 with the threaded portion 48 a of the tie bar 48 and engage the connecting plate 54 with the tie bar 48. To do.
[0042]
At the same time, the servo motor 20 of the pressure increasing device 40 is driven to displace the compression member 22 to increase the hydraulic pressure in the cylinder liquid chamber 14 and output the required mold clamping force from the piston rod 16. Yes (see FIG. 2).
[0043]
Note that the adjustment of the mold clamping force by the pressure increasing device 40 can be appropriately performed by the drive control unit 34 of the servo motor 20 based on the detection signal by the pressure sensor 32, as shown in FIG. That's right.
[0044]
Application example 2
FIG. 7 shows another application example in which the sealed hydraulic pressure booster 40 according to the present invention is applied to a mold clamping device 42 of an injection molding machine.
[0045]
In this embodiment, in the first application embodiment described above, a servo motor 66 is used instead of the moving cylinder 56, and the screw member 68a of the drive shaft 68 of the servo motor 66 is fixed to the connecting plate 54. The connecting plate 54 is configured to be able to be moved forward and backward by being screwed to 70, and the servo motor 72 is used in place of the operation cylinder 62 for driving the half nut 60. The other configuration is the same as that of the embodiment shown in FIG. 6. Therefore, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.
[0046]
According to this embodiment, the mold opening / closing operation and the mold clamping operation can all be controlled by the servo motors 66, 72, 20.
[0047]
The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and many design changes can be made without departing from the spirit of the present invention.
[0048]
【The invention's effect】
As described above, the hermetic hydraulic pressure booster according to the present invention has the piston part of the piston rod hermetically housed in the cylinder liquid chamber of the hermetic hydraulic cylinder, and is arranged adjacent to the cylinder liquid chamber. In the hermetic hydraulic pressure booster configured to control the hydraulic pressure in the cylinder fluid chamber to obtain a boosted output from the piston rod, a fluid passage is provided that communicates the cylinder fluid chamber and the pressure increase control unit. In addition, a compression member configured to be moved forward and backward by a servo motor is inserted and disposed in the liquid passage, and a pressure sensor for detecting a hydraulic pressure generated in the cylinder liquid chamber or an output obtained from the piston rod is provided. By adopting a configuration that controls the servo motor so that the detected pressure maintains a preset pressure, the configuration can be simplified and miniaturized. , Yet it is possible to enlarge the design flexibility such as shape and volume, it is possible to suppressed as much as possible the occurrence of liquid leakage and noise in the cylinder fluid chambers.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an embodiment of a hermetic hydraulic pressure booster according to the present invention.
FIG. 2 is a schematic sectional view showing another embodiment of the hermetic hydraulic pressure booster according to the present invention.
FIG. 3 is a schematic sectional view showing still another embodiment of the sealed hydraulic pressure booster according to the present invention.
4 is an enlarged cross-sectional view of a main part showing details of a pressure increase control unit of the hermetic hydraulic pressure booster shown in FIG. 3;
FIG. 5 is a schematic cross-sectional view showing another embodiment of a hermetic hydraulic pressure booster according to the present invention.
6 is a schematic side view of a mold clamping device showing a first applied embodiment in which the hermetic hydraulic pressure booster according to the present invention shown in FIG. 2 is applied to a mold clamping device of an injection molding machine.
7 is a schematic side view of a mold clamping device showing a second applied embodiment in which the hermetic hydraulic pressure booster according to the present invention shown in FIG. 2 is applied to a mold clamping device of an injection molding machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Sealed hydraulic cylinder 12 Pressure increase control part 14 Cylinder liquid chamber 16 Piston rod 16a Piston part 18 Liquid path 18a Orthogonal liquid path 20 Servo motor 20a Rotor core 20b Stator coil 21 Output shaft 22 Compression member 23 Spline member 24 Feed screw 26 Rotation nut 27 Bearing 28 Connecting portion 30 Spring member 32 Pressure sensor 34 Drive control portion 36 Seal member 38 Communication hole 40 Sealed hydraulic pressure intensifier 42 Mold clamping device 44 Fixed mold 46 Fixed plate 48 Tie bar 48a Screw portion 50 Moving mold 52 Moving Plate 54 Connecting plate 56 Moving cylinder 58 Piston rod 60 Half nut 62 Operation cylinder 64 Nozzle part 66 of injection molding machine Servo motor 68 Drive shaft 68a Screw part 70 Nut member 72 Servo motor

Claims (7)

The piston portion of the piston rod is hermetically housed in the cylinder fluid chamber of the hermetic hydraulic cylinder, and the fluid pressure in the cylinder fluid chamber is controlled by the pressure increase control unit disposed adjacent to the cylinder fluid chamber to increase the pressure from the piston rod. In a sealed hydraulic pressure booster configured to obtain an output,
A fluid passage that communicates between the cylinder fluid chamber and the pressure increase control unit is provided, and a compression member configured to be moved forward and backward by a servo motor is inserted and disposed in the fluid passage, and the fluid pressure or piston generated in the cylinder fluid chamber A pressure sensor for detecting an output obtained from the rod, and the servo motor is controlled so that the pressure detected by the pressure sensor maintains a preset pressure. Pressure device. 2. The hermetic hydraulic pressure booster according to claim 1, wherein the fluid passage communicating the cylinder fluid chamber and the pressure boosting control unit is arranged in parallel to the axis of the piston rod. The liquid passage that communicates between the cylinder fluid chamber and the pressure increase control unit has a configuration in which an orthogonal fluid passage that extends perpendicularly to and communicates with a liquid passage that is disposed parallel to the axial center of the piston rod. 2. A hermetic hydraulic pressure intensifier according to claim 1, wherein a compression member configured to be moved back and forth by a servo motor is inserted and disposed in the orthogonal fluid passage. The pressure increase control unit transmits the rotation drive of the servo motor to the rotating nut through the connecting portion, and advances the compression member together with the feed screw screwed together with the rotation of the rotating nut to increase the inside of the cylinder liquid chamber. 2. The hermetic hydraulic pressure intensifier according to claim 1, wherein the device is configured to obtain a predetermined output from the piston rod. The pressure-increasing control unit holds the feed screw coupled to the compression member by a rotating nut, and rotatably attaches the rotating nut and attaches the rotor core of the servo motor to the outer periphery of the rotating nut. The stator coil of the servo motor is disposed so as to surround, and the rotary nut is driven to rotate integrally with the rotor core of the servo motor, and the compression member is moved forward together with the feed screw. Sealed hydraulic pressure booster. The sealed hydraulic cylinder is provided with a seal member at each of a contact portion between the piston rod and the piston portion, and a contact portion between the cylinder fluid chamber and the compression member in the fluid passage communicating the pressure increase control portion. Item 2. A sealed hydraulic pressure intensifier according to item 1. The sealed hydraulic cylinder is provided with a seal member at the contact portion with the piston rod and the contact portion with the compression member in the fluid passage communicating the cylinder fluid chamber and the pressure increase control portion, and the piston portion of the piston rod The cylinder fluid chamber is provided with a communication hole that communicates between the pressure increasing chamber side and the back pressure chamber side, and the increased pressure output from the piston rod corresponds to the pressure increase in the cylinder fluid chamber corresponding to the cross-sectional area of the piston rod. The hermetic hydraulic pressure intensifier according to claim 1, wherein the device is obtained based on a difference in hydraulic action area between the chamber side and the back pressure chamber side .

Images