KR101374859B1 - Fluid-pressure cylinder - Google Patents

Abstract

The present invention relates to a hydraulic cylinder comprising a hollow casing with an internal space; a rod bar to be moved inside the internal space and to protrude from the casing; a protruding blade member which protrudes from the outer circumference of the rod bar and of which the diameter is greater than that of the rod bar; a fixture member shaped into a divided ring; a cylindrical large diameter part with a central through-hole to come in contact with the inner wall of the casing; a bushing member extending downwards from the large diameter part with a small diameter part of which the diameter is smaller than that of the large diameter part; a rising fluid inlet connected to the inside of the casing to move the rod bar upwards; a lowering fluid inlet connected to the inside of the casing to move the rod bar downwards; and a cap joined to the casing to seal the bottom of the casing. Therefore, the hydraulic cylinder lowers production costs by simplifying the structure; and minimizes the risk of failure.

Description

Hydraulic cylinder {Fluid-pressure cylinder}

The present invention relates to a hydraulic cylinder, and more particularly, even if the amount of fluid provided or pulsation occurs, the position of each part is fixed, so that precise work can be performed, and arbitrary locking is prevented from being released. It relates to a hydraulic cylinder that can be.

In general, hydraulic cylinders are used as various mechanical parts, the shape is also various, and is used for various purposes.

The hydraulic cylinder is used in a fork crane or a crane in the case of a large size, it can be used as a variety of mechanical component parts, even a part of the mold in the case of a small size.

It is well known that the hydraulic cylinder is widely used to reciprocate a mechanical part at a constant stroke distance.

As a medium for reciprocating a certain stroke, the hydraulic cylinder uses a fluid such as oil, and any mechanical part reciprocates in accordance with the injection or discharge of the fluid.

However, the conventional hydraulic cylinder uses fluid as its working medium, so that the amount of fluid provided is undesirably changed or undesired movement is caused by the pulsation that may occur in the fluid flow to perform sophisticated work. Where there was a problem that defective products can occur.

For example, when the shape of the product in the mold has a shape of a groove or a hole, a mold pin corresponding to the shape of the groove or hole is inserted into a cavity corresponding to the shape of the product, and fine movement of the mold pin is not desired. If it occurs at the moment, the depth of the groove or hole of the product is different from the design, so that a defect occurs.

In addition, the conventional hydraulic cylinder has a complicated configuration or structure in order to always maintain a constant amount of the fluid provided, and to exclude the influence of the pulsation that may occur in the flow of the fluid, making the production difficult and expensive There was a problem.

In addition, there is a technique that adopts a gear coupling as a structure that enables the conventional reciprocating movement, but the structure using the gear coupling is a risk of failure, and the unwanted parts of the parts due to the backlash, etc. present in the gear coupling There was a problem that the movement must occur.

In addition, the conventional hydraulic cylinder may be installed in an opposite manner (upside down), in which case there is a problem that the locking is released at an unwanted moment by moving the parts by their own weight.

Registered Korean Patent Publication No. 10-1323256, registered on October 23, 2013.

The present invention has been proposed to solve the above-mentioned problems, the object is that the structure is simple and inexpensive to manufacture, the risk of failure can be minimized, and whether there is a change in the amount of fluid provided Alternatively, even if a pulsation occurs, the position of each component is fixed without change, so that precise work can be performed, and the movement of the components can be prevented by self-weight so that the locking can be prevented from being released randomly. have.

Hydraulic cylinder according to the present invention for achieving the above object, has a hollow form having an inner space, the upper surface has a through hole which is a through hole, the fastener is composed of a groove cut toward the outer periphery from the inner wall A casing having an accommodating groove, a rod rod which can be moved in the inner space of the casing, has a rod shape, and an upper portion thereof protrudes from the casing through the upper through hole and protrudes from an outer circumference of the rod rod. The protruding wing member having a diameter larger than that of the rod rod, and is inserted into the fixing tool receiving groove can be moved up and down along the inner wall of the casing by moving the position, and the shape of the divided ring The fastener member is provided with a cylindrical having a central through-hole in the center, the rod rod in the central through-hole Passed through and fitted to the outer circumference of the rod, and positioned below the protruding wing member, and has a large diameter portion in contact with the inner wall of the casing, and a small diameter portion extending downward of the large diameter portion and having a diameter smaller than the large diameter portion, When the rod is moved to the lowest end, the lower end of the large diameter portion is in communication with the bushing member located above the fixing tool receiving groove, the inner space of the casing, the space between the small diameter portion of the bushing member and the inner wall of the casing The fluid injection port for injecting fluid to move the rod rod upwards and communicates with the inner space of the casing, injecting fluid into the space between the upper portion of the protruding wing member and the inner wall of the casing to lower the rod rod A descending fluid inlet for moving to and sealing the bottom surface of the casing by being combined with the casing It characterized in that it comprises a.

In addition, in the hydraulic cylinder according to the present invention, the fixture receiving groove has a groove inclined downwardly toward the outer periphery in the inner wall of the casing and a groove vertical portion extending from the groove inclined portion and formed in a vertical direction, The upper outer circumferential edge of the fastener member has an inclined outer inclined portion inclined to correspond to the groove inclined portion, and the fastener member is easily inserted into and separated from the fastener receiving groove.

In addition, in the hydraulic cylinder according to the present invention, the rising fluid inlet is provided at a position corresponding to the fixing tool receiving groove in the horizontal direction, characterized in that the rising fluid inlet and the fixing tool receiving groove is directly communicated.

In addition, in the hydraulic cylinder according to the present invention, both ends of the outer periphery of the units constituting the fastener member are chamfered in the direction toward the virtual center of one ring shape formed by combining the units constituting the fastener member, The outer circumferential ends of the respective units constituting the fastener member have a diameter smaller than the center of the respective units, so that the fastener member is easily moved when the fastener member is moved up and down in the inner space of the casing.

In addition, in the hydraulic cylinder according to the present invention, the outer circumferential lower end of the small diameter portion of the bushing member has a bushing slope inclined downward to face the center of the bushing member, and the upper inner circumferential edge of the fastener member corresponds to the bushing slope portion. It characterized in that the inclined inclined fastener inner side inclined portion, the fastener member is moved to the lower side of the bushing member to facilitate the movement to support the bushing member.

In addition, in the hydraulic cylinder according to the present invention, the center of the cap has a central hole through the cap which is a through hole, the rising fluid inlet communicates with the central hole through the cap, the lower end of the rod rod diameter of the central portion of the rod It has a larger diameter and is in contact with the inner wall of the casing, has a diameter expansion portion in contact with the bottom surface of the fastener member, when the fluid flows from the rising fluid inlet, the incoming fluid is the rod rod under the rod It provides a force to move upward, the diameter expansion portion is characterized in that for moving the fixture member upward.

In addition, in the hydraulic cylinder according to the present invention, the bottom of the cap, the groove which is dug toward the top, and has a tool insertion groove which is provided in a pair symmetrical to face each other with respect to the center of the cap, the tool insertion groove After inserting the tool into the rotating the cap is characterized in that to facilitate the coupling of the cap and the casing.

In addition, in the hydraulic cylinder according to the present invention, the protruding wing member is formed with a fluid through hole which is a hole penetrated in the vertical direction, the fluid provided from the descending fluid inlet passes through the fluid through hole and the bushing member downwards. It is characterized by applying a force in the direction of movement.

In addition, in the hydraulic cylinder according to the present invention, the outer periphery of the large diameter portion of the bushing member is further formed with a bushing fluid mumm groove grooved toward the inner circumference, the fluid flowing along the inner circumference of the bushing member stayed in the bushing fluid mumm groove. By flowing the pressure of the fluid flowing below the bushing member is lowered characterized in that the leakage of the fluid is prevented.

In addition, in the hydraulic cylinder according to the present invention, a rod fluid mumm groove, which is a groove which is dug toward the inner circumference, is further formed on the outer circumference of the rod rod positioned below the protruding wing member of the rod rod, and the fluid flowing along the outer circumference of the rod rod. The water stays in the rod fluid mumm groove and flows, so that the pressure of the fluid flowing downward of the rod fluid mumm groove is lowered to prevent leakage of the fluid.

In addition, in the hydraulic cylinder according to the present invention, the coil spring is fitted between the protruding wing member and the bushing member, the coil spring has a relatively small diameter at one end and a relatively large diameter at the other end to have a cross-sectional shape. Having a trapezoidal shape, the bushing member is moved downward by its own weight is prevented by the coil spring is characterized in that the arbitrary separation of the fixture member is prevented.

According to the hydraulic cylinder according to the present invention, the structure is simple and can be manufactured inexpensively, the risk of failure can be minimized, and even if there is a change in the amount of fluid provided or a pulsation occurs, the position of each part varies. It can be fixed and precise work can be performed, and the parts can be prevented from moving by their own weight, thereby preventing the locking from being released randomly.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

1 is a view showing the inside of a hydraulic cylinder according to an embodiment of the present invention
FIG. 2 is an exploded perspective view of the internal configuration of the hydraulic cylinder shown in FIG. 1. FIG.
3 is a plan view showing the fastener member of the hydraulic cylinder shown in FIG.
4 is a bottom view of the cap of the hydraulic cylinder shown in FIG.
5 and 6 are views for explaining the use state of the hydraulic cylinder shown in FIG.

Hereinafter, a hydraulic cylinder according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 6 show a hydraulic cylinder according to an embodiment of the present invention, Figure 1 is a view showing the inside of the hydraulic cylinder according to an embodiment of the present invention, Figure 2 is a hydraulic pressure shown in Figure 1 FIG. 3 is a plan view showing the fastener member of the hydraulic cylinder shown in FIG. 1, FIG. 4 is a bottom view of the cap of the hydraulic cylinder shown in FIG. 1, and FIGS. 5 and 6. Is a view for explaining the state of use of the hydraulic cylinder shown in FIG.

As shown in the figure, the hydraulic cylinder 100 according to an embodiment of the present invention is a casing 10, rod rod 20, the protruding wing member 30, the fixture member 40, the bushing The member 50, the rising fluid inlet 60, the falling fluid inlet 70, and the cap 80 are included.

The casing 10 has a hollow shape having an inner space, and has a top through hole 12 that is a through hole on the upper surface thereof, and has a fixture receiving groove 14 formed of a groove that is dug toward the outer circumference of the inner wall. will be.

The rod rod 20 may be moved in the inner space of the casing 10, has a rod shape, and an upper portion thereof may protrude from the casing 10 by passing through the upper through hole 12. .

The protruding wing member 30 protrudes from the outer circumference of the rod rod 20 to have a diameter larger than that of the rod rod 20.

The fastener member 40 may be inserted into the fastener receiving groove 14 and moved up and down along the inner wall of the casing 10 by moving the position by the provided hydraulic pressure. It is.

The bushing member 50 is provided in a cylindrical shape having a central through hole 52 in the center, the rod rod 20 is passed through the central through hole 52 is fitted to the outer circumference of the rod rod 20, Located below the protruding wing member 30, the large diameter portion 54 in contact with the inner wall of the casing 10, and extends below the large diameter portion 54, the diameter less than the large diameter portion 54 Branch has a small diameter portion 56, the lower end of the large diameter portion 54 is located above the fixing tool receiving groove 14 when the rod rod 20 is moved to the lower end.

The rising fluid inlet 60 communicates with the inner space of the casing 10, and injects fluid into the space between the small diameter portion 56 of the bushing member 50 and the inner wall of the casing 10 to load the rod. The rod 20 is to move upward.

The lower fluid inlet 70 communicates with an inner space of the casing 10, and injects fluid into a space between the upper side of the protruding wing member 30 and the inner wall of the casing 10 to load the rod 20. ) To move downward.

The cap 80 is coupled to the casing 10 to seal the bottom surface of the casing 10.

On the other hand, the fixture receiving groove 14 is a groove which extends from the inner wall of the casing 10 toward the outer periphery but inclined downward and extends from the groove inclined portion 16 in a vertical direction. It has a vertical portion 17.

In addition, the upper outer circumferential edge of the fastener member 40 has a fastener outer side inclined portion 42 inclined at an inclination corresponding to the groove inclined portion 16, so that the fastener member 40 has the fastener accommodation groove 14. It is easy to move into and out of the insert.

In addition, the rising fluid inlet 60 is provided at a position corresponding to the fixing tool receiving groove 14 in the horizontal direction, and the rising fluid inlet 60 and the fixing tool receiving groove 14 are configured to be in direct communication. Can be.

In addition, both ends of the outer periphery of each unit constituting the fastener member 40, as shown in FIG. 3, are directed toward the virtual center of one ring shape formed by combining the units constituting the fastener member 40. It is chamfered in the direction.

Accordingly, the outer circumferential ends of the respective units constituting the fastener member 40 have a diameter smaller than the center of the respective units so that the fastener member 40 can be moved up and down within the inner space of the casing 10. When it is easy to move.

On the other hand, the outer peripheral lower end of the small diameter portion 56 of the bushing member 50 has a bushing inclined portion 58 inclined downward to face the center of the bushing member 50, the upper end of the fixture member 40 The inner circumferential edge has a fixture-side inclined portion 44 inclined at an inclination corresponding to the bushing inclined portion 58.

Therefore, the fastener member 40 is moved downward to the bushing member 50 to facilitate the movement to support the bushing member 50.

In addition, the bottom surface of the cap 80, the groove which is dug upwards and has a tool insertion groove 84 is provided in a pair symmetrical to face each other with respect to the center of the cap 80, the tool insertion Inserting a tool into the groove 84 and then rotating the cap 80 to facilitate the coupling of the cap 80 and the casing 10.

On the other hand, the protruding wing member 30 is formed with a fluid through hole 32 which is a hole penetrated in the vertical direction, the fluid provided from the falling fluid inlet 70 passes through the fluid through hole 32 It is preferable to apply a force in the direction in which the bushing member 50 moves downward.

In addition, the outer periphery of the large diameter portion 54 of the bushing member 50 is further formed with a bushing fluid mumm groove 59 is a groove that is dug toward the inner circumference, the fluid flowing along the inner circumference of the bushing member 50 is the bushing It is preferable that the pressure of the fluid flowing downward of the bushing member 50 is reduced by staying in the fluid recess groove 59 and flowing to prevent leakage of the fluid.

In addition, the rod fluid mumm groove 28 which is a groove that is dug toward the inner periphery of the rod rod 20 located below the protruding wing member 30 of the rod rod 20 is further formed, the rod The fluid flowing along the outer circumference of the rod 20 stays in the rod fluid mumm groove 28 and flows so that the pressure of the fluid flowing downward of the rod fluid mumm groove 28 is lowered to prevent leakage of the fluid. desirable.

In addition, the coil spring 90 is sandwiched between the protruding wing member 30 and the bushing member 50, one end of the coil spring 90 has a relatively small diameter and the other end has a relatively large diameter The cross-sectional shape has a trapezoidal shape, the movement of the bushing member 50 downward by its own weight is prevented by the coil spring 90 to prevent the arbitrary separation of the fixture member 40, providing hydraulic pressure Even if this is not present, the state in which the fastener member 40 is inserted into the fastener accommodation groove 14 is maintained and the locking is maintained.

Hydraulic cylinder 100 according to an embodiment of the present invention having the configuration as described above is operated as follows.

First, as shown in Figure 1, the rod rod 20 is moved downward to the state that the fastener member 40 is inserted into the fixture receiving groove (14).

In this state, the outer circumference of the bushing member 50 and the inner circumference of the fastener member 40 are in contact with each other.

In this state, the molding die pin (not shown) is coupled to the top surface of the rod 20 to be used in a cavity (not shown) of the mold.

In addition, in this state, since the fastener member 40 is inserted into the fastener receiving groove 14, the rod rod 20 is prevented from moving upward and downward to completely move the molding die pin (not shown). It is also prevented to prevent product defects.

In this state, when it is necessary to replace the molding die pin (not shown), the fluid is injected into the rising fluid inlet (60).

Then, the fluid introduced through the rising fluid inlet 60 provides the force to move the fastener member 40 toward the center of the casing 10, while the fastener member 40 and the casing 10 are provided. Is moved between the inner wall of the, and provides a force in the direction to move the bushing member 50 upward from the large diameter portion 54 of the bushing member 50.

Then, the bushing member 50 starts to move upward, and the bushing member 50 continues to move upward, and the bushing inclined portion 58 and the fixture inner side inclined portion 44 come into contact with each other. The fixture member 40 is moved below the bushing member 50.

This is because the fluid flowing through the rising fluid inlet 60 continuously provides the force for moving the fixture member 40 toward the center of the casing 10.

Subsequently, the bushing member 50 continuously rises to push the protruding wing member 30 upward, and the rod rod 20 is moved upward. This movement is continued until the rod rod 20 can no longer move upward as shown in FIG. 5.

When the rod rod 20 is moved to the uppermost in this way, the molding die pin (not shown) coupled to the rod rod 20 is removed and replaced with a new one.

The structure in which the molding die pin (not shown) is separated in the state in which the rod rod 20 is moved upward is described in detail in the technology filed by the present applicant, and thus detailed description thereof will be omitted. The present invention does not focus on a structure in which a molding die pin (not shown) is separated, but moves the rod rod 20 by using hydraulic pressure in the up and down direction, and also in the up and down direction of the rod rod 20. This is because it relates to structures that prevent unwanted movement.

On the other hand, after replacing the molding die pin (not shown) with a new one, the rod rod 20 should be lowered to return to the initial position.

To this end, the fluid is injected through the falling fluid inlet (70).

At this time, of course, the fluid is not injected into the rising fluid inlet (60).

When the fluid is injected through the descending fluid inlet 70, the fluid rises along the inner wall of the casing 10 and flows between the upper wall of the casing 10 and the upper surface of the protruding wing member 30 and the rod rod. Force is provided in the direction of moving 20 downward.

In addition, some of the fluid is passed through the fluid through hole 32 of the protruding wing member 30 is moved upward of the bushing member 50 to provide a force in the direction to move the bushing member 50 downward. do.

Accordingly, the fastener member 40 is also moved downwards, and when it reaches the point where the fastener receiving groove 14 meets, it is inserted into the fastener receiving groove 14 and the bushing member 50 and the rod rod 20. Continues to descend to return to the initial state, which is the state shown in FIG.

In addition, the fluid flowing along the inner circumference of the bushing member 50 due to the presence of the bushing fluid mummy groove 59 and the rod fluid mummy groove 28, or the fluid flowing downward of the rod fluid mummy groove 28. The pressure of the pressure drop is to prevent unwanted leakage of fluid.

In other words, when the pressure of the fluid is high, the possibility of leakage of the fluid increases, but when the pressure of the fluid drops, the possibility of leakage of the fluid is significantly reduced.

In addition, due to the coil spring 90 embedded between the protruding wing member 30 and the bushing member 50, the fixture member 40 is inserted into the fixture receiving groove 14 even when there is no fluid supply. The state is maintained to prevent unlocking.

That is, when the installation is not the same as the shape shown in Figure 5, but installed upside down in the opposite shape of the state shown in Figure 5, in the absence of hydraulic pressure, the bushing member 50 protrudes by the weight of the bushing member 50 There is a possibility that the member 30 moves in the direction in which it is located. In this case, since the movement of the bushing member 50 is prevented by the restoring force of the coil spring 90, the fastener member 40 can maintain the state inserted into the fastener receiving groove 14.

Meanwhile, in the present embodiment, as shown in FIGS. 1 and 5, the rising fluid inlet 60 has been described as being formed in a position corresponding to the direction in which the fixture member 40 is positioned, but is limited thereto. Of course not.

That is, as shown in Figure 6 the center of the cap 80 to form a through-hole cap central through hole 82, the rising fluid inlet 60 is configured to communicate with the cap central through hole 82 Even the same effect can be obtained.

At this time, the diameter extension portion 24 is coupled to the rod rod 20. The diameter expanding portion 24 is located at the lower end of the rod rod 20, has a diameter larger than the diameter of the central portion of the rod rod 20 and in contact with the inner wall of the casing 10, the fixture member It is in contact with the bottom of the (40).

Therefore, when the fluid flows from the ascending fluid inlet 60 communicated with the cap center through-hole 82, the incoming fluid moves the rod rod 20 upward from the rod rod 20 below. Provides a force, and the diameter expansion portion 24 moves the fixture member 40 upwards.

At this time, the upper circumferential edge of the fastener member 40 has a groove inclined portion 16, and the groove receiving portion 14 has a groove inclined portion 16, so that the diameter expansion portion 24 When the fastener member 40 is pushed upward, the fastener member 40 is naturally moved upwardly along the groove inclined portion 16 to be the same as described above.

10. Casing 12. Top through hole
14. Fixture groove 16. Groove slope
17.Vertical groove 20.Rod rod
24. Diameter Expansion Unit 28. Rod Fluid Mumm Groove
30. Protruding wing member 32. Fluid passing hole
40. Fixture member
42. Fixtures Outside Slopes 44. Fixtures Inside Slopes
50. Bushing member 52. Central through hole
54. Large diameter 56. Small diameter
58. Bushing Inclination 59. Bushing Fluid Mum Home
60. Upward fluid inlet 70. Downward fluid inlet
80.Cap 82.Cap center through hole
84. Tool insert groove 90. Coil spring

Claims (11)

A casing 10 having a hollow shape having an inner space, and having a top through hole 12 that is a through-hole on the upper surface thereof, and having a fixture receiving groove 14 formed of a groove that is dug toward the outer circumference of the inner wall;
A rod rod 20 which can be moved in the inner space of the casing 10, has a rod shape, and an upper portion thereof protrudes from the casing 10 through the upper through hole 12;
A protruding wing member 30 protruding from an outer circumference of the rod rod 20 and having a diameter larger than that of the rod rod 20;
A fastener member 40 which is inserted into the fastener receiving groove 14 and moved up and down along the inner wall of the casing 10 by being moved by a hydraulic pressure provided, and having a shape of a divided ring;
It is provided in a cylindrical shape having a central through hole 52 in the center, the rod rod 20 is passed through the central through hole 52 is fitted to the outer circumference of the rod rod 20, of the protruding wing member 30 Located in the lower portion, the large diameter portion 54 in contact with the inner wall of the casing 10, and the small diameter portion 56 extending downward of the large diameter portion 54 and having a diameter smaller than the large diameter portion 54 When the rod rod 20 is moved to the lower end, the lower end of the large diameter portion 54 is located above the fixture receiving groove 14 while the inner wall of the casing 10 and the fixture member 40 A bushing member 50 inserted between the bushing members 50 to prevent movement of the rod rod 20 in the vertical direction;
In communication with the inner space of the casing 10, the rod rod 20 is moved upward by injecting fluid into the space between the small diameter portion 56 of the bushing member 50 and the inner wall of the casing 10. Upward fluid inlet (60) to make;
The descending fluid communicating with the inner space of the casing 10 and injecting fluid into the space between the upper side of the protruding wing member 30 and the inner wall of the casing 10 to move the rod rod 20 downward. Inlet 70;
And a cap (80) coupled to the casing (10) to seal the bottom surface of the casing (10). The method of claim 1,
The fixture receiving groove 14 is a groove inclined portion 16 extending from the inner wall of the casing 10 toward the outer circumference and inclined downward and extending from the groove inclined portion 16 in a vertical direction. Has 17,
The upper outer peripheral edge of the fastener member 40 has a fixture inclined outer side inclined portion 42 inclined to correspond to the groove inclined portion 16,
Hydraulic cylinder, characterized in that the fastener member 40 is made to move easily inserted into and separated from the fixture receiving groove (14). The method of claim 1,
The rising fluid inlet 60 is provided at a position corresponding to the fixing tool receiving groove 14 in the horizontal direction, so that the rising fluid inlet 60 and the fixing tool receiving groove 14 are directly in communication with each other. cylinder. The method of claim 1,
The outer circumferential ends of the respective units constituting the fastener member 40 are chamfered in a direction toward the virtual center of one ring shape formed by combining the units constituting the fastener member 40, thereby providing the fastener member 40. The outer circumferential ends of the respective units constituting) have a diameter smaller than the center of the respective units, so that the movement is easy when the fastener member 40 is moved up and down in the inner space of the casing 10. Hydraulic cylinder, characterized in that. The method of claim 1,
At the lower end of the outer periphery of the small diameter portion 56 of the bushing member 50 has a bushing inclined portion 58 inclined downward to face the center of the bushing member 50,
The upper inner circumferential edge of the fastener member 40 has a fastener inner side inclined portion 44 inclined in a slope corresponding to the bushing inclined portion 58,
Hydraulic cylinder, characterized in that the fastener member 40 is moved downward to support the bushing member 50 is moved downward of the bushing member (50). The method of claim 1,
In the center of the cap 80 has a through-cap central through hole 82,
The rising fluid inlet 60 is in communication with the cap central through-hole 82,
The lower end of the rod rod 20 has a diameter larger than the diameter of the central portion of the rod rod 20 and in contact with the inner wall of the casing 10, the diameter expansion portion in contact with the bottom surface of the fastener member 40 Has 24,
When the fluid flows from the rising fluid inlet 60, the inflow fluid provides a force to move the rod rod 20 upward from the rod rod 20, and the diameter expansion part 24. The hydraulic cylinder, characterized in that for moving the fastener member 40 upwards. The method of claim 1,
On the bottom of the cap 80,
It is a groove which is dug toward the top, and has a tool insertion groove 84 provided in pairs symmetrical to face each other with respect to the center of the cap 80,
Hydraulic cylinder, characterized in that to facilitate the coupling of the cap (80) and the casing (10) by rotating the cap (80) after inserting the tool into the tool insertion groove (84). The method of claim 1,
The protruding wing member 30 is formed with a fluid through hole 32 which is a hole penetrated in the vertical direction, so that the fluid provided from the descending fluid inlet 70 passes through the fluid through hole 32 and the bushing member. Hydraulic cylinder, characterized in that for applying a force in the direction in which 50 is moved downward. The method of claim 1,
On the outer circumference of the large diameter portion 54 of the bushing member 50, a bushing fluid mumm groove 59, which is a groove dug toward the inner circumference, is further formed, and the fluid flowing along the inner circumference of the bushing member 50 is the bushing fluid mumm. The hydraulic cylinder characterized in that the pressure of the fluid flowing downward of the bushing member (50) is lowered by staying in the groove (59) and flowing to prevent leakage of the fluid. The method of claim 1,
On the outer circumference of the rod rod 20 located below the protruding wing member 30 of the rod rod 20, a rod fluid mumm groove 28, which is a groove that is dug toward the inner circumference, is further formed. The fluid flowing along the outer periphery of 20) stays in the rod fluid mumm groove 28 and flows, so that the pressure of the fluid flowing downward of the rod fluid mumm groove 28 is lowered to prevent leakage of the fluid. Hydraulic cylinder. The method of claim 1,
A coil spring 90 is inserted between the protruding wing member 30 and the bushing member 50. The coil spring 90 has one end having a relatively small diameter and the other end has a relatively large diameter. The shape has a trapezoidal shape, the movement of the bushing member 50 downward by its own weight is prevented by the coil spring (90) is characterized in that the arbitrary separation of the fixture member 40 is prevented cylinder.

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