JP4895342B2 - Fluid pressure cylinder - Google Patents

Description

  The present invention relates to a fluid pressure cylinder.

In a cylinder that generates a thrust by supplying a fluid, a method of increasing the bore diameter and a method of increasing a fluid supply pressure are known as methods for increasing the thrust.
For example, when a large thrust is obtained in a relatively small cylinder, a hydraulic cylinder is often selected that uses oil as the supplied fluid to increase the supply pressure of the fluid. However, when a hydraulic cylinder is used, there is a problem that an auxiliary device such as a hydraulic device for supplying pressurized oil is required, which is disadvantageous in terms of cost and space.

  In the case of an air cylinder that uses air as the fluid to be supplied, there is a limit to the air pressure that can be supplied at the factory. Therefore, the cylinder thrust is increased by increasing the supply air pressure to increase the cylinder thrust. It was difficult. Therefore, a method of increasing the cylinder thrust by increasing the bore diameter of the air cylinder is generally used.

  However, if an air cylinder is used to generate thrust equivalent to that of a hydraulic cylinder, the bore diameter of the air cylinder needs to be considerably increased. When the arrangement space of the air cylinder is limited, there is a problem that the air cylinder cannot be arranged when the bore diameter is increased.

  Furthermore, a method of using an air hydro booster that pressurizes oil using the pressure of supply air and supplies the pressurized oil to a cylinder is also known. However, even in this method, it is necessary to provide an air hydro booster in addition to the cylinder, and there is a problem that both cost and space are disadvantageous.

For this reason, various cylinder technologies that can solve the above-described problems and generate a larger thrust using only supply air have been proposed (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-93912 (page 3, FIG. 1, etc.)

In the above-mentioned Patent Document 1, an outer piston that slides in a cylinder tube of a cylinder body, a hollow outer rod, an inner rod that has one end fixed to the cylinder body and penetrates the outer piston so as to be relatively slidable, and an inner rod The structure of the cylinder provided with the inner piston attached to the outer rod and sliding relative to the outer rod is disclosed.
According to the cylinder having this configuration, the pressure of the supply air can be received by the pressure receiving surface of the outer piston and the pressure receiving surface of the inner piston as compared with a general cylinder, so that the generated thrust is substantially doubled. I was able to.

However, when a larger thrust is exerted on the cylinder by using the above-described technique, a number of cylinders are further incorporated inside. In this case, there is a problem that the structure of the cylinder becomes complicated. In addition, since the structure is complicated, it is difficult to manufacture the structure.
Furthermore, there are problems that the piston rod becomes thin and the rigidity is lowered by incorporating many cylinders inside.

The present invention has been made to solve the above problems,
An object of the present invention is to provide a fluid pressure cylinder that can generate thrust equivalent to that in the case of hydraulic pressure supply only by air supply and can be reduced in size.

In order to achieve the above object, the present invention provides the following means.
The present invention provides a housing, a first fluid chamber and a second fluid chamber provided in the housing, and one wall surface of the first fluid chamber, and a first fluid chamber provided to be movable in a predetermined direction. A communication channel that forms a wall surface of the piston and one of the second fluid chambers, and connects the second piston, the first fluid chamber, and the second fluid chamber, which are movably provided in the predetermined direction. And an internal fluid filled in all of the first fluid chamber, the second fluid chamber, and the communication flow path in the entire movement range of the first piston in the predetermined direction , The projected area on the vertical surface with respect to the predetermined direction on the surface in contact with the internal fluid is formed to be larger than the projected area on the vertical surface with respect to the predetermined direction on the surface in contact with the internal fluid of the first piston, On the first piston The second piston provides a fluid pressure cylinder that is driven by the pressure of the feed fluid which is supplied from the parts is applied.

  According to the present invention, the projected area of the second piston is formed larger than the projected area of the first piston, and the first fluid chamber, the second fluid chamber, and the communication flow path are filled with the internal fluid. A large thrust can be generated in the second piston by multiplying the force related to the pressure of the supply fluid applied to the first piston by the projected area ratio of both pistons.

  That is, a predetermined pressure is generated in the internal fluid in the first fluid chamber by a force related to the pressure of the supply fluid applied via the first piston. Since the first fluid chamber and the second fluid chamber are connected via a communication channel, a predetermined pressure is also applied to the internal fluid in the second fluid chamber. Since the projected area of the second piston is larger than the projected area of the first piston, the force acting on the second piston is larger than the force acting on the first piston.

From the above, by setting the ratio of the projected area of the first piston and the projected area of the second piston to a predetermined value, it is generated in the second piston regardless of the magnitude of the force acting on the first piston. The magnitude of the thrust can be set to a predetermined value. Therefore, for example, a thrust equivalent to that in the case of hydraulic pressure supply can be generated in the fluid pressure cylinder only by air supply.
In addition, as compared with the cylinder disclosed in Patent Document 1 described above, it is not necessary to dispose a piston or rod inside the piston or rod, so that the fluid pressure cylinder can be easily downsized.

In the above invention, the internal fluid is preferably an incompressible fluid.
According to the present invention, since the incompressible fluid is used as the internal fluid, a larger thrust can be generated by the second piston as compared with the case where the compressive fluid is used. That is, by using an incompressible fluid as the internal fluid, it is possible to prevent a part of the thrust from being consumed for the compression of the internal fluid in the second fluid chamber, so that the thrust can be efficiently generated in the second piston. it can.
For example, by using oil, which is an incompressible fluid, as the internal fluid and using air (air) as the supply fluid, it is possible to generate a thrust equivalent to that in the case of hydraulic supply only by air supply in the fluid pressure cylinder. it can.

  In the above invention, the housing is provided with a third fluid chamber, and the third fluid chamber is divided into two small chambers and is provided so as to be movable in the predetermined direction. 3 pistons are provided, and a piston rod is provided between the first piston and the third piston to move the first piston and the third piston in conjunction with each other. In addition, it is desirable to provide an opening through which the supply fluid flows in and out from the outside.

According to the present invention, the third fluid chamber is divided into two small chambers by the third piston, and the supply fluid flows into and out of each small chamber, and the first piston and the third piston are connected to the piston rod. Therefore, the force generated in the third piston by the supplied fluid can be transmitted to the first piston.
That is, the supply fluid pressure is applied to the third piston by flowing the supply fluid into and out of the two small chambers from the opening. Therefore, a force related to the supply fluid acts on the third piston, and the force related to the supply fluid is transmitted to the first piston via the piston rod.

  In the above invention, the projection area of the surface of the third piston in contact with the supply fluid onto the vertical surface with respect to the predetermined direction is projected onto the surface of the first piston in contact with the internal fluid onto the vertical surface with respect to the predetermined direction. It is desirable that it be formed to be larger than the area.

According to the present invention, since the projected area of the third piston is larger than the projected area of the first piston, the pressure of the supply fluid received by the third piston is amplified and transmitted to the internal fluid in the first fluid chamber. Can do.
That is, the force received by the third piston is the product of the pressure of the supply fluid and the projected area of the third piston, and the force received by the first piston is the product of the pressure of the internal fluid and the projected area of the first piston. Since the forces acting on both pistons are balanced, the pressure acting on the first piston is the pressure acting on the third piston multiplied by the ratio of the projected area of the third piston to the projected area of the first piston. Therefore, the pressure of the supply fluid received by the third piston is amplified and transmitted to the internal fluid in the first fluid chamber.

In the above invention, preferably, the second piston is provided with a biasing member that biases the second piston toward a direction in which the volume of the second fluid chamber is reduced .
According to the present invention, since the second piston is urged by the urging member toward the direction of decreasing the volume of the second fluid chamber, when the pressure of the internal fluid in the second fluid chamber decreases, The two pistons can be reliably moved in the direction of reducing the volume of the second fluid chamber.

In the above invention, when operating the second piston in the direction of increasing the volume of the second fluid chamber , a supply fluid of a predetermined pressure is supplied from the outside to the third fluid chamber, and the second piston is When the second fluid chamber is moved in the direction of decreasing the volume, it is preferable that the pressure of the supply fluid in the third fluid chamber is reduced from the predetermined pressure.

According to the present invention, the supply fluid of a predetermined pressure is supplied from the outside to the third fluid chamber, whereby the third piston is pressed and moved in the direction of the first fluid chamber. When the third piston moves, the first piston connected by the piston rod moves in a direction to reduce the volume in the first fluid chamber direction , and the volume of the first fluid chamber decreases. When the volume of the first fluid chamber is reduced, the internal fluid in the first fluid chamber flows into the second fluid chamber via the communication channel. The second piston moves in the direction of increasing the volume of the second fluid chamber by the inflow of the internal fluid.

Further, when the pressure of the supply fluid of the third fluid chamber is reduced below a predetermined pressure, the force will suited in a direction to increase the second fluid chamber of volume which acts on the second piston, the second piston by a biasing member the balance of forces would unsuitable in a direction to reduce the volume of the second fluid chamber acting on collapses. The urging member presses and moves the second piston in a direction to reduce the volume of the second fluid chamber, and decreases the volume of the second fluid chamber. When the volume of the second fluid chamber decreases, the internal fluid flows into the first fluid chamber via the communication channel. The first fluid chamber increases in volume due to the inflow of internal fluid. When the volume of the first fluid chamber increases, the first piston moves toward the third fluid chamber, and the third piston connected by the piston rod also moves.

  In the above invention, when operating the second piston in one of the predetermined directions, a supply fluid of a predetermined pressure is supplied from the outside to one of the two small chambers, and the other of the two small chambers is When the pressure of the internal supply fluid is reduced from the predetermined pressure and the second piston is operated in the other of the predetermined directions, the supply fluid of the predetermined pressure is supplied from the outside to the other of the two small chambers. At the same time, in one of the two small chambers, it is desirable that the pressure of the supply fluid inside is reduced from the predetermined pressure.

According to the present invention, the supply fluid of a predetermined pressure is supplied to one of the two small chambers, and the pressure of the supply fluid inside the other small chamber is reduced from the predetermined pressure, so that the third piston can It is pressed and moved from the room toward the other small room. When the third piston moves, the first piston connected by the piston rod also moves, and for example, the volume of the first fluid chamber decreases. When the volume of the first fluid chamber is reduced, the internal fluid in the first fluid chamber flows into the second fluid chamber via the communication channel. The second piston moves in the direction of increasing the volume of the second fluid chamber by the inflow of the internal fluid.

In addition, while supplying a supply fluid of a predetermined pressure to the other of the two small chambers, and reducing the pressure of the supply fluid inside the one of the small chambers from the predetermined pressure, the third piston can be It is pressed and moved toward the small room. When the third piston moves, the first piston connected by the piston rod also moves, and for example, the volume of the first fluid chamber increases. When the volume of the first fluid chamber increases, the internal fluid in the second fluid chamber flows into the first fluid chamber via the communication channel. The second piston moves in the direction of reducing the volume of the second fluid chamber by the outflow of the internal fluid.

In the above invention, when operating the second piston in one of the predetermined directions, a supply fluid of a predetermined pressure is supplied from the outside to one of the two small chambers, and the other of the two small chambers is When the pressure of the internal supply fluid is reduced from the predetermined pressure and the second piston is operated in the other of the predetermined directions, the supply fluid of the predetermined pressure is supplied from the outside to the other of the two small chambers. In one of the two small chambers, the pressure of the internal supply fluid is reduced from the predetermined pressure, and the biasing member always reduces the volume of the second piston in the direction of the second fluid chamber. It is desirable to press it.

According to the present invention, the supply fluid of a predetermined pressure is supplied from the outside to the third fluid chamber, whereby the third piston is pressed and moved in the direction of the first fluid chamber. When the third piston moves, the first piston connected by the piston rod moves in a direction to reduce the volume in the first fluid chamber direction , and the volume of the first fluid chamber decreases. When the volume of the first fluid chamber is reduced, the internal fluid in the first fluid chamber flows into the second fluid chamber via the communication channel. The second piston moves in the direction of increasing the volume of the second fluid chamber by the inflow of the internal fluid.

Further, when the pressure of the supply fluid of the third fluid chamber is reduced below a predetermined pressure, the force will suited in a direction to increase the second fluid chamber of volume which acts on the second piston, the second piston by a biasing member the balance of forces would unsuitable in a direction to reduce the volume of the second fluid chamber acting on collapses. The urging member presses and moves the second piston in the direction of decreasing the volume in the second fluid chamber direction , and decreases the volume of the second fluid chamber. When the volume of the second fluid chamber decreases, the internal fluid flows into the first fluid chamber via the communication channel. The first fluid chamber increases in volume due to the inflow of internal fluid. When the volume of the first fluid chamber increases, the first piston moves toward the third fluid chamber, and the third piston connected by the piston rod also moves.

Furthermore, since the urging member always presses the second piston in the direction of reducing the volume in the direction of the second fluid chamber, pressure is always applied to the internal fluid in the first fluid chamber and the second fluid chamber. Since pressure is always applied to the internal fluid, for example, when the moving direction of the second piston is switched, there is no timing when the pressure disappears, and the second piston can always be driven.

In the above invention, each of the casings includes one of the first fluid chamber, the second fluid chamber, the third fluid chamber, the first piston, the second piston, and the third piston. It is desirable that a piston is provided, and the piston rod is provided only on one surface of the third piston.
According to the present invention, a single rod type fluid pressure cylinder can be realized.

In the above invention, each of the casings includes two first fluid chambers, the second fluid chamber, the first piston, the second piston, and one third fluid chamber. The third piston, the piston rod is provided on one and other surfaces of the third piston, the first fluid chamber on both sides of the third fluid chamber and the third piston, It is desirable that the second fluid chamber, the first piston, and the second piston are disposed.
According to the present invention, a double rod type fluid pressure cylinder can be realized.

  In the above invention, the central axis of the first piston and the central axis of the second piston are arranged to coincide with each other, and the second piston has a through hole sharing the central axis with the second piston. The cylindrical first guide member is formed on the first piston and shares a central axis with the first piston, and the guide member is inserted into the through hole so as to be relatively movable. The fluid pressure cylinder according to any one of 10.

  According to the present invention, since the guide member is inserted into the through hole so as to be relatively movable, the guide member and the second piston can be relatively moved. Moreover, since the attitude | position of a 2nd piston is controlled by the fitting of a guide member and a through-hole, it can be hold | maintained uniformly.

  According to the fluid pressure cylinder of the present invention, the projected area of the second piston projected in the predetermined direction which is the moving direction is formed larger than the projected area of the first piston, and the first fluid chamber and the second fluid Since the internal fluid is filled in the chamber and the communication flow path, a large thrust is generated on the second piston by multiplying the force related to the pressure of the supply fluid applied to the first piston by the projected area ratio of both pistons. be able to. That is, by setting the ratio of the projected area of the first piston and the projected area of the second piston to a predetermined value, it is possible to generate a thrust equivalent to that in the case of hydraulic pressure supply only by air supply.

  Further, as compared with the cylinder disclosed in the above-mentioned Patent Document 1, it is not necessary to dispose the piston or rod further inside the piston or rod, so that the effect of easily miniaturizing the fluid pressure cylinder is achieved.

[First Embodiment]
Hereinafter, an air-hydro cylinder according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.
FIG. 1 is a cross-sectional view illustrating the overall configuration of an air-hydro cylinder according to this embodiment.
As shown in FIG. 1, the air-hydro cylinder (fluid cylinder) 1 includes a cylinder body (housing) 3 and lids 5 </ b> A and 5 </ b> B disposed at both ends of the cylinder body 3.
The lids 5A and 5B are fixed to the cylinder body 3 using a fixing member such as a screw.

Inside the cylinder body 3, a pneumatic cylinder 7, a first hydraulic cylinder 9, and a second hydraulic cylinder 11 that share a central axis (predetermined direction) C and the central axis of the cylinder body 3 are formed in series. Yes.
The pneumatic cylinder 7 is formed open to one end face of the cylinder body 3, and the open portion is closed by a lid 5A. The first hydraulic cylinder 9 is formed open to the pneumatic cylinder 7 and is separated from the second hydraulic cylinder 11 by a partition wall 13. The second hydraulic cylinder 11 is formed open to the other end surface of the cylinder body 3.

A substantially plate-like pneumatic piston (third piston) 15 is arranged in the pneumatic cylinder 7 so as to be movable in the direction of the central axis C. A pneumatic chamber (third fluid chamber) 17 formed by the pneumatic cylinder 7 and the lid 5A is divided into two working chambers (small chambers) 19A and 19B by a pneumatic piston 15. The cylinder body 3 has flow holes (openings) 21A and 21B communicating with the outside with respect to the working chambers 19A and 19B, respectively.
Supply air (supply fluid) AR pressurized to a predetermined pressure from the outside through the flow holes 21A and 21B flows into the working chambers 19A and 19B, and the supply air flows out from the working chambers 19A and 19B. It is configured.
An annular seal member 23 is provided on the circumferential surface of the pneumatic piston 15 to prevent air from flowing between the working chambers 19A and 19B. The pneumatic piston 15 is connected to a first hydraulic piston, which will be described later, by a piston rod 25, and is configured to move in the direction of the central axis C together with the first hydraulic piston.
As the seal member 23, a known member such as a rubber ring formed in an annular shape can be used and is not particularly limited.

A substantially plate-like first hydraulic piston (first piston) 27 is arranged in the first hydraulic cylinder 9 so as to be movable in the direction of the central axis C. The first hydraulic piston 27 forms a first hydraulic chamber (first fluid chamber) 29 together with the first hydraulic cylinder 9. The first hydraulic chamber 29 is filled with oil (internal fluid) OL.
An annular seal member 23 is provided on the circumferential surface of the first hydraulic piston 27 to prevent the oil in the first hydraulic chamber 29 from flowing out to the pneumatic chamber 17 side.

  A second hydraulic piston (second piston) 31 is arranged in the second hydraulic cylinder 11 so as to be movable in the central axis C direction. The second hydraulic piston 31 and the second hydraulic cylinder 11 form a second hydraulic chamber (second fluid chamber) 33. The second hydraulic chamber 33 is filled with oil OL. The cylinder body 3 is formed with a communication flow path 35 that connects the first hydraulic chamber 29 and the second hydraulic chamber 33 and allows oil OL to flow between the first and second hydraulic chambers 29 and 33.

The second hydraulic piston 31 is generally configured by a plate-like portion 37 that forms the second hydraulic chamber 33 together with the second hydraulic piston 31, and a protruding portion 39 that protrudes from the plate-like portion 37 toward the lid 5B. .
An oil supply hole 41 is formed in the plate-like portion 37, and oil is supplied from the oil supply hole 41 to the first hydraulic chamber 29, the communication channel 35, and the second hydraulic chamber 33. In the oil supply hole 41, a screw 43 for preventing oil from flowing out from the second hydraulic chamber 33 is disposed.
An annular seal member 23 is provided on the circumferential surface of the plate-like portion 37 to prevent the oil in the second hydraulic chamber 33 from flowing out to the pneumatic chamber 17 side.
A plurality of coil springs (biasing members) 45 are arranged between the plate-like portion 37 and the lid 5B at equal intervals on a circumference centered on the central axis C.
A hole 47 is formed in the lid 5 </ b> B, and the protruding portion 39 protrudes outside through the hole 47.

  In the pneumatic piston 15, the projection area onto the vertical plane with respect to the central axis C direction on the surface in contact with the supply air of the pneumatic piston 15 is the projection area onto the vertical plane with respect to the central axis C direction on the surface in contact with the oil of the first hydraulic piston 27. It is formed so as to be larger. In the second hydraulic piston 31, the projected area of the surface of the second hydraulic piston 31 in contact with the oil on the surface perpendicular to the direction of the central axis C is perpendicular to the surface of the first hydraulic piston 27 in contact with the oil along the direction of the central axis C. It is formed to be larger than the projected area.

  Note that the fluid filled in the first hydraulic chamber 29, the communication channel 35, and the second hydraulic chamber 33 may be an incompressible fluid, and is not limited to the oil OL as described above.

The first hydraulic piston 27 is provided with a guide rod (guide member) 49 extending toward the lid 5B. The guide rod 49 is inserted into a partition hole 51 formed in the partition wall 13 and a guide hole (through hole) 53 formed in the second hydraulic piston 31.
An annular seal member 23 is provided in the partition hole 51 and the guide hole 53, and the oil flows between the first hydraulic chamber 29 and the second hydraulic chamber 33, and the oil from the second hydraulic chamber 33 to the outside, respectively. Prevents the outflow.

Next, the operation of the air-hydro cylinder 1 having the above configuration will be described.
FIG. 2 is a diagram illustrating a state in which the second hydraulic piston 31 has advanced in the air-hydro cylinder 1 of FIG.
FIG. 1 shows a state in which the second hydraulic piston 31 in the air-hydro cylinder 1 is retracted. First, the operation when the second hydraulic piston 31 moves forward from this state will be described.

When the second hydraulic piston 31 is moved forward, first, supply air is supplied from the circulation hole 21A to the working chamber 19A, and supply air in the working chamber 19B is discharged from the circulation hole 21B to the outside.
When the supply air is supplied to the working chamber 19A, as shown in FIG. 2, the pneumatic piston 15 is pushed in the second hydraulic chamber 33 direction (right direction in FIG. 2) by the supply air pressure, and the second hydraulic chamber 33 direction. Move to.
When the pneumatic piston 15 moves, the first hydraulic piston 27 connected by the piston rod 25 similarly moves in the direction of the second hydraulic chamber 33.

When the first hydraulic piston 27 moves in the direction of the second hydraulic chamber 33, the oil in the first hydraulic chamber 29 is pushed and pressurized by the first hydraulic piston 27.
The pressure of the pressurized oil in the first hydraulic chamber 29 is also transmitted to the oil in the second hydraulic chamber 33 through the communication channel 35. The oil pressure transmitted to the second hydraulic chamber 33 presses the second hydraulic piston 31 to move (advance) in the direction of the lid 5B.

Next, the operation when the second hydraulic piston 31 moves backward will be described.
First, the case where the air hydro cylinder 1 is a double acting cylinder will be described.
When the second hydraulic piston 31 is retracted from the state shown in FIG. 2, first, supply air is supplied from the circulation hole 21B to the working chamber 19B, and supply air in the working chamber 19A is supplied from the circulation hole 21A to the outside. Spill into.
When supply air is supplied to the working chamber 19B, as shown in FIG. 1, the pneumatic piston 15 is pushed in the direction of the lid 5A (left direction in FIG. 1) by the differential pressure of the supply air in the working chambers 19A and 19B. Move in the direction of the lid 5A.
When the pneumatic piston 15 moves, the first hydraulic piston 27 connected by the piston rod 25 similarly moves in the direction of the lid 5A.

When the first hydraulic piston 27 moves in the direction of the lid 5A, the volume of the first hydraulic chamber 29 increases at the same time. Oil OL flows from the second hydraulic chamber 33 into the first hydraulic chamber 29 via the communication channel 35. The volume of the second hydraulic chamber 33 decreases due to the outflow of the oil OL, and the second hydraulic piston 31 is forcibly retracted in the direction of the first hydraulic chamber 29 (the left direction in FIG. 1).
At this time, the coil spring 45 serves as an auxiliary when the second hydraulic piston 31 is retracted toward the first hydraulic chamber 29.

Next, the case where the air-hydro cylinder 1 is a single-acting cylinder will be described.
When the second hydraulic piston 31 is retracted from the state shown in FIG. 2, first, supply of supply air from the flow hole 21A into the working chamber 19A is stopped, and the supply air pressure in the working chamber 19A is changed to the outside. To open. Then, the pressure of the oil OL in the first hydraulic chamber 29 and the second hydraulic chamber 33 is reduced, and the force with which the oil OL pushes the second hydraulic piston 31 decreases.
When the force by which the coil spring 45 pushes the second hydraulic piston becomes larger than the force by which the oil OL pushes the second hydraulic piston 31, the second hydraulic piston 31 pushes in the first hydraulic chamber 29 direction (left direction in FIG. 1). And retreat.

  When the second hydraulic piston 31 moves backward, the volume of the second hydraulic chamber 33 decreases. The oil OL in the second hydraulic chamber 33 flows into the first hydraulic chamber 29 via the communication channel 35, and the volume of the first hydraulic chamber 29 increases. The first hydraulic piston 27 is pushed backward by the oil OL, and the pneumatic piston 15 connected by the piston rod 25 is also moved backward.

  In addition, since the guide rod 49 and the guide hole 53 are inserted in the second hydraulic piston 31 so as to be relatively movable with respect to the central axis C direction, the posture with respect to the central axis C is maintained and the second hydraulic piston 31 is maintained in the central axis C direction. Move to.

Next, generation of thrust of the second hydraulic piston in the air-hydro cylinder 1 will be described.
First, assuming that the pressure of the supply air supplied to the pneumatic chamber 17 is Pa and the projected area on the surface perpendicular to the direction of the central axis C on the surface in contact with the supply air of the pneumatic piston 15 is Sa, the supply air acts on the pneumatic piston 15. The force Fa in the direction of the central axis C is
Fa = Pa × Sa (1)
It is expressed.
Since the pneumatic piston 15 and the first hydraulic piston 27 are connected by the piston rod 25, the force Fa also acts on the first hydraulic piston 27.

Assuming that the projected area of the surface of the first hydraulic piston 27 in contact with the oil onto the vertical plane with respect to the central axis C direction is Sy1, the hydraulic pressure Py1 in the first hydraulic chamber 29 is
Py1 = Fa / Sy1 (2)
It is expressed.
Here, from the formulas (1) and (2), the hydraulic pressure Py1 is
Py1 = Fa / Sy1 = Pa × Sa / Sy1 (3)
It can be expressed as. Since the projected area Sa of the pneumatic piston 15 is larger than the projected area Sy1 of the first hydraulic piston 27, Sa / Sy1> 1. Therefore, the equation (3) shows that the hydraulic pressure Py1 in the first hydraulic chamber 29 is higher than the pressure Pa of the supply air.

The hydraulic pressure Py2 in the second hydraulic chamber 33 is the same as the hydraulic pressure Py1 in the first hydraulic chamber 29 due to Pascal's principle.
Py2 = Py1 = Fa / Sy1 (4)
It is expressed.

Assuming that the projected area on the surface perpendicular to the central axis C direction of the surface of the second hydraulic piston 31 in contact with oil is Sy2, the force (thrust) Fy2 acting on the second hydraulic piston 31 in the central axis C direction is
Fy2 = Py2 × Sy2 (5)
It is expressed.
Here, from Formula (4) and Formula (5), the thrust Fy2 is
Fy2 = Fa × Sy2 / Sy1 (6)
It is expressed. Since the projected area Sy2 of the second hydraulic piston 31 is larger than the projected area Sy1 of the first hydraulic piston 27, Sy2 / Sy1> 1. Therefore, it is shown from the equation (6) that the thrust Fy2 acting on the second hydraulic piston 31 is larger than the force Fa acting on the pneumatic piston 15 based on the pressure Pa of the supply air.

  According to the above configuration, the projected area Sy2 of the second hydraulic piston 31 is formed larger than the projected area Sy1 of the first hydraulic piston 27, and the communication path between the first hydraulic chamber 29 and the second hydraulic chamber 33 is communicated. Since 35 is filled with oil OL, the projected area ratio (Sy2 / Sy1) of each piston 27, 29 is multiplied by the force Fa related to the supply air AR applied to the first hydraulic piston 27 to the second hydraulic piston 31. In addition, a large thrust Fy2 can be generated.

Therefore, by setting the ratio of the projected area Sy1 of the first hydraulic piston 27 and the projected area Sy2 of the second hydraulic piston 31 to a predetermined value, regardless of the magnitude of the force Fa acting on the first hydraulic piston 27, The magnitude of the thrust Fy2 generated in the second hydraulic piston 31 can be set to a predetermined value.
Specifically, even when only air is supplied to the air-hydro cylinder 1, it is possible to generate thrust equivalent to that of a hydraulic pressure supply cylinder.
Further, as compared with the cylinder disclosed in Patent Document 1 described above, it is not necessary to dispose a piston or rod inside the piston or rod, so that the size of the air-hydro cylinder 1 can be easily reduced. .

Since oil that is an incompressible fluid is used as the fluid that fills the first hydraulic chamber 29, the communication flow path 35, and the second hydraulic chamber 33, the second fluid is compared with the case where a compressive fluid is used. The hydraulic piston 31 can generate a large thrust Fy2.
That is, by using the incompressible fluid oil, it is possible to prevent a part of the thrust from being consumed for the compression of the fluid in the second hydraulic chamber 33, and thus the thrust Fy2 is efficiently generated in the second hydraulic piston 31. Can be made.

The pneumatic chamber 17 is divided into two working chambers 19A and 19B by the pneumatic piston 15, and the supply air AR flows into and out of the respective working chambers 19A and 19B, and the first hydraulic piston 27 and the pneumatic piston 15 are connected to each other. Since the piston rod 25 moves in conjunction with each other, the force Fa generated in the pneumatic piston 15 by the supply air can be transmitted to the first hydraulic piston 27.
That is, the supply air pressure is applied to the pneumatic piston 15 by flowing the supply air into and out of the working chambers 19A and 19B from the flow holes 21A and 21B. Therefore, a force Fa by supply air acts on the pneumatic piston 15, and the force Fa is transmitted to the first hydraulic piston 27 through the piston rod 25.

Since the projected area Sa of the pneumatic piston 15 is larger than the projected area Sy1 of the first hydraulic piston 27, the pressure Pa of the supply air received by the pneumatic piston 15 is amplified and transmitted to the oil OL in the first hydraulic chamber 29. be able to.
That is, the force Fa received by the pneumatic piston 15 is the product of the pressure Pa of the supply air and the projected area Sa of the pneumatic piston 15, and the force received by the first hydraulic piston 27 is the oil pressure Py 1 and the first hydraulic piston 27. This is the product of the projected area Sy1. Since the forces acting on the pistons 15 and 27 are balanced, the pressure Py1 acting on the first hydraulic piston 27 is obtained by multiplying the pressure Pa acting on the pneumatic piston 15 by the ratio (Sa / Sy1) of the projected area Sa to the projected area Sy1. Become a thing. Therefore, the pressure Pa of the supply air received by the pneumatic piston 15 is amplified and transmitted to the oil OL in the first hydraulic chamber 29.

Since the air-hydro cylinder 1 is driven only by the supply air AR, an auxiliary device such as a hydraulic device is not required, so that the installation space can be reduced and the installation cost can be reduced.
Further, since a hydraulic device is not required, vibration caused by the hydraulic device does not occur. In addition, since the hydraulic pressure with pressure fluctuation is not supplied from the hydraulic device, it is possible to prevent the occurrence of cylinder vibration based on the fluctuation of hydraulic pressure.
Furthermore, since no hydraulic device is used, piping parts such as a hydraulic hose that supplies oil between the hydraulic device and the cylinder are not required. Since the hydraulic piping parts need to withstand high pressure compared to the pneumatic piping parts, they are large and solid. For this reason, since no hydraulic piping parts are required, workability, assembly cost, and piping space can be reduced.

FIG. 3 is a cross-sectional view illustrating another embodiment of the air-hydro cylinder of FIG.
As described above, the posture of the second hydraulic piston 31 may be stabilized by inserting the guide rod 49 and the guide hole 53 so as to be relatively movable, or the posture of the second hydraulic piston 31 is stabilized. In this case, the guide rod 49 and the guide hole 53 may not be provided as shown in FIG.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the air-hydro type cylinder of this embodiment is the same as that of the first embodiment, but in the first embodiment, it is applied to a single-rod type air-hydro type cylinder, whereas the double-rod type It is different in that it is applied to an air-hydro cylinder. Therefore, in the present embodiment, only components that are different from those in the first embodiment will be described using FIG. 4, and descriptions of the same components and the like will be omitted.
FIG. 4 is a cross-sectional view illustrating the overall configuration of the air-hydro cylinder according to the present embodiment.
In addition, about the component same as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 4, the air-hydro cylinder (fluid cylinder) 101 is disposed at both ends of the first cylinder body (housing) 103 </ b> A, the second cylinder body (housing) 103 </ b> B, and the air-hydro cylinder 101. And a lid 5B.
The first cylinder body 103A and the second cylinder body 103B are fixed to each other using a fixing member such as a screw.

  Inside the first cylinder body 103A, a pneumatic cylinder 7, a first hydraulic cylinder 9, and a second hydraulic cylinder 11 having a common central axis C and the central axis of the first cylinder body 103A are formed in series. Has been. The pneumatic cylinder 7 is formed to be opened at one end face of the first cylinder body 103A, and the open portion is closed by the second cylinder body 103B.

  Inside the second cylinder body 103B, a first hydraulic cylinder 9 and a second hydraulic cylinder 11 having a central axis C and a central axis common to the second cylinder body 103B are formed in series.

Next, the operation of the air-hydro cylinder 101 having the above configuration will be described.
FIG. 4 shows a state in which the second hydraulic piston 31 of the first cylinder body 103A in the air-hydro cylinder 101 has advanced, and a state in which the hydraulic piston 31 of the second cylinder body 103B has retracted.
Since the operation when the second hydraulic piston 31 moves forward and backward in the first cylinder body 103A is the same as that in the first embodiment, the description thereof is omitted.

An operation when the second hydraulic piston 31 moves forward in the second cylinder main body 103B will be described.
When the second hydraulic piston 31 in the second cylinder body 103B is moved forward, first, supply air is supplied from the circulation hole 21B to the working chamber 19B, and supply air in the working chamber 19A is supplied from the circulation hole 21A to the outside. Spill.
When the supply air is supplied to the working chamber 19B, the pneumatic piston 15 is pushed leftward in FIG. 4 by the supply air pressure, and moves toward the second hydraulic chamber 33 in the second cylinder body 103B.
Since the subsequent operation is the same as that of the first embodiment, the description thereof is omitted.

  According to the above configuration, the supply air flows into and out of the working chambers 19A and 19B to advance (retreat) the second hydraulic piston 31 of the first cylinder body 103A, and at the same time, the second cylinder body 103B. The second hydraulic piston 31 can be moved backward (advanced).

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the description has been made by applying to an air-hydro cylinder driven by supplying air, but the present invention is not limited to an air-hydro cylinder driven by air as a compressible fluid. The present invention can be applied to a cylinder driven by various other fluids such as an incompressible fluid.
In the case of a cylinder driven by an incompressible fluid, a larger thrust can be generated in the second hydraulic piston than when driven by a compressive fluid such as air.

  Further, in the above-described embodiment, the description has been made by applying to the configuration in which the pneumatic piston 15 and the first hydraulic piston 27 are connected by the piston rod 25. However, the present invention is not limited to this configuration. 15 and the first hydraulic piston 27 can be applied to other various configurations.

It is sectional drawing explaining the whole structure of the air hydro type | mold cylinder which concerns on the 1st Embodiment of this invention. It is a figure explaining the state which the 2nd hydraulic piston advanced in the air-hydro type cylinder of FIG. It is sectional drawing explaining the other Example of the air hydro type | mold cylinder of FIG. It is sectional drawing explaining the whole structure of the air hydro type | mold cylinder which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

1,101 Air-hydro cylinder (fluid cylinder)
3 Cylinder body (frame)
15 Pneumatic piston (3rd piston)
17 Pneumatic chamber (third fluid chamber)
19A, 19B Working room (small room)
21A, 21B Flow hole (opening)
25 piston rod 27 first hydraulic piston (first piston)
29 First hydraulic chamber (first fluid chamber)
31 Second hydraulic piston (second piston)
33 Second hydraulic chamber (second fluid chamber)
35 Communication channel 45 Coil spring (biasing member)
49 Guide rod (guide member)
53 Guide hole (through hole)
103A First cylinder body (housing)
103B Second cylinder body (housing)
C Center axis (predetermined direction)
AR supply air (supply fluid)
OL oil (internal fluid)
Sa, Sy1, Sy2 projected area

Claims (11)

The body,
A first fluid chamber and a second fluid chamber provided in the housing;
A first piston that forms one wall surface of the first fluid chamber and is movable in a predetermined direction;
A second piston that forms one wall surface of the second fluid chamber and is movable in the predetermined direction;
A communication channel connecting the first fluid chamber and the second fluid chamber;
An internal fluid filled in all of the first fluid chamber, the second fluid chamber, and the communication flow path in the entire movement range of the first piston in the predetermined direction ,
The projected area of the surface of the second piston in contact with the internal fluid on the surface perpendicular to the predetermined direction is larger than the projected area of the surface of the first piston in contact with the internal fluid on the surface perpendicular to the predetermined direction. Formed into
A fluid pressure cylinder in which the second piston is driven when a pressure of a supply fluid supplied from the outside is applied to the first piston.   The fluid pressure cylinder according to claim 1, wherein the internal fluid is an incompressible fluid. The housing is provided with a third fluid chamber,
The third fluid chamber is provided with a third piston that divides the third fluid chamber into two small chambers and is movable in the predetermined direction.
Between the first piston and the third piston is provided a piston rod for moving the first piston and the third piston in conjunction with each other,
3. The fluid pressure cylinder according to claim 1, wherein the two small chambers are provided with openings through which a supply fluid flows in and out from the outside. 4.   The projected area of the surface of the third piston in contact with the supply fluid on the vertical surface with respect to the predetermined direction is larger than the projected area of the surface of the first piston in contact with the internal fluid on the vertical surface with respect to the predetermined direction. 4. The fluid pressure cylinder according to claim 3, wherein the fluid pressure cylinder is formed. 5. The fluid pressure according to claim 1, wherein the second piston is provided with a biasing member that biases the second piston toward a direction in which the volume of the second fluid chamber is reduced. Cylinder. When operating the second piston toward the direction of increasing the volume of the second fluid chamber , a supply fluid of a predetermined pressure is supplied from the outside to the third fluid chamber,
The fluid pressure cylinder according to claim 5, wherein when the second piston is moved in a direction to reduce the volume of the second fluid chamber , the pressure of the supply fluid in the third fluid chamber is reduced from the predetermined pressure. When operating the second piston in one of the predetermined directions,
A supply fluid of a predetermined pressure is supplied from the outside to one of the two small chambers, and the pressure of the internal supply fluid is reduced from the predetermined pressure in the other of the two small chambers,
When operating the second piston in the other direction of the predetermined direction,
The supply fluid having a predetermined pressure is supplied from the outside to the other of the two small chambers, and the pressure of the internal supply fluid is reduced from the predetermined pressure in one of the two small chambers. The fluid pressure cylinder described in 1. When operating the second piston in one of the predetermined directions,
A supply fluid of a predetermined pressure is supplied from the outside to one of the two small chambers, and the pressure of the internal supply fluid is reduced from the predetermined pressure in the other of the two small chambers,
When operating the second piston in the other direction of the predetermined direction,
A supply fluid having a predetermined pressure is supplied to the other of the two small chambers from the outside, and the pressure of the internal supply fluid is reduced from the predetermined pressure in one of the two small chambers,
The fluid pressure cylinder according to claim 5, wherein the biasing member always presses the second piston in a direction to reduce the volume of the second fluid chamber. The casing is provided with one each of the first fluid chamber, the second fluid chamber, the third fluid chamber, the first piston, the second piston, and the third piston. ,
The fluid pressure cylinder according to any one of claims 6 to 8, wherein the piston rod is provided only on one surface of the third piston. The casing includes two first fluid chambers, the second fluid chamber, the first piston, the second piston, one third fluid chamber, and the third piston, respectively. Is provided,
The piston rod is provided on one and other surfaces of the third piston, and the first fluid chamber, the second fluid chamber, and the first fluid are respectively provided on both sides of the third fluid chamber and the third piston. The fluid pressure cylinder according to any one of claims 6 to 8, wherein a piston and the second piston are arranged. The central axis of the first piston and the central axis of the second piston are arranged to coincide with each other,
The second piston has a through hole that shares a central axis with the second piston,
The first piston is formed with a cylindrical guide member sharing a central axis with the first piston,
The fluid pressure cylinder according to any one of claims 1 to 10, wherein the guide member is inserted into the through hole so as to be relatively movable.

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