Patent Grant
7526993
The present invention relates to a fluid pressure cylinder apparatus having a throttle valve, in which a fluid pressure cylinder is provided with a throttle valve, and a movement control of a piston is performed by means of adjusting a flow of pressurized fluid with the throttle valve.
Hitherto, as this kind of fluid pressure cylinder apparatus having a throttle valve, an apparatus in which a moving speed of a piston is controlled by adjusting a flow of pressurized fluid supplied to or discharged from a pressure chamber with a throttle valve, an apparatus in which the piston is stopped at an end of stroke in a buffered manner by means of limiting a flow of fluid discharged from a pressure chamber with a throttle valve when the piston approaches the end of the stroke, or the like is known.
In such a cylinder apparatus, generally, as the throttle valve, a variable throttle valve configured to adjust a square measure of an opening of an orifice by advancing and retreating a cone-shaped valve rod is used and the variable throttle valve is attached to a cylinder body.
In
The throttle valve 50 is constructed such that a valve holder 60 is attached to a valve hole 59 formed in the cylinder body 51, and a valve rod 61 provided with a cone-shaped adjusting portion 61a at a tip end thereof is movably mounted in the valve holder 60 in an advancing and retreating manner in a direction of an axis line of the valve hole 59 upon rotating operation. In addition, at a base end portion 61b where a male screw of the valve rod 61 is provided, a lock nut 63 for preventing the valve rod 61 from being rotated by vibration or the like after the square measure of the opening is adjusted is attached.
In the conventional fluid pressure cylinder apparatus, the throttle valve attached to the cylinder body is configured to adjust the square measure of the opening of the orifice by means of advancing and retreating the valve rod in the direction of the axis line. Accordingly, a dimension of the valve rod in a direction along the axis line is large, and in addition, an operating area for advancing and retreating the valve rod has to be secured. Consequently, there has been a large limitation on downsizing.
Further, there has also been a problem that when the valve rod, the valve holder, the lock nut, or the like is widely protruding outward of the cylinder body, it tends to be impeditive for treating the cylinder, or for attaching other devices in the vicinity of the cylinder.
An object of the present invention is to provide a fluid pressure cylinder apparatus having a throttle valve configured for a throttle valve to be compactly attached to a cylinder body by means of miniaturizing and simplifying the throttle valve.
So as to achieve the above-described object, according to the present invention, the fluid pressure cylinder apparatus having a throttle valve, including a piston moving in an inner part of a cylinder body by means of action of the fluid pressure, a pressure chamber for exerting the action of the fluid pressure on the piston, a port for supplying or discharging a pressurized fluid to the pressure chamber and a variable throttle valve for adjusting a flow of the pressurized fluid so as to control a movement of the piston is provided. The throttle valve includes a cylindrically shaped valve rod housed in a circular valve hole formed in the cylinder body in a condition of being hooked in a direction of a center axis line of the valve hole, while being rotatable around the center axis line of the valve hole. A first flow path hole and a second flow path hole for the pressurized fluid is opened at a side face and a bottom face of the valve hole, and the valve rod is formed such that an outer peripheral surface is formed in a manner so as to be in close sliding contact with an inner peripheral surface of the valve hole. Further, a connecting hole whose first hole opening at one end is opened at a side face of the valve rod and is allowed to communicate with the first flow path hole, and a second hole opening at the other end is opened at a bottom face of the valve rod and is allowed to communicate with the second flow path hole is formed in an inner part of the valve rod. Furthermore, a flow adjusting groove for adjusting a connected square measure of the first flow path hole and the first hole opening along with a rotating operation is provided at an outer periphery of the valve rod, and the flow adjusting groove extends in a circumferential direction from a position of the first hole opening as a base end and a groove width gradually narrows toward a tip end side and a groove depth gradually shallows at the same time.
In the present invention, the valve rod is preferable to be disposed in the valve hole in a non-protruding condition, and a device for hooking the valve rod in the valve hole is preferable to be a ring-shaped stopping ring.
In a concrete embodiment of the present invention, the throttle valve is provided with a function as a speed control valve for controlling a moving speed of the piston, and either one of the first flow path hole or the second flow path hole is allowed to communicate with the port, and the other is allowed to communicate with the pressure chamber.
In another concrete embodiment of the present invention, the throttle valve is configured to be provided with a function as a cushion valve for stopping the piston at an end of a stroke in a buffered manner, and when the piston approaches the end of the stroke, a fluid in the pressure chamber at a discharge side is discharged from the port through the throttle valve.
More in detail, a cushion chamber is formed in an inner part of the cylinder body, in which when the piston is in the middle of the stroke, the cushion chamber is allowed to communicated with the pressure chamber, whereas the cushion chamber is interrupted from the pressure chamber when the piston approaches the end of the stroke. Further the port is allowed to communicate with the cushion chamber and one and the other of the first flow path hole and the second flow path hole of the throttle valve are respectively allowed to communicate with the cushion chamber and the pressure chamber.
According to the present invention, since the throttle valve for adjusting a flow is configured such that the flow can be adjusted only by rotating the valve rod around its axis line in the valve hole, the throttle valve can be constructed at a compact and simple structure with small number of parts in comparison with the conventional throttle valve that advances and retreats the valve rod in a direction of the axis line, and the throttle valve can be compactly assembled in the fluid pressure cylinder.
a is an elevation showing a valve rod in a throttle valve.
b is a side elevation showing the valve rod in the throttle valve.
a is a cross-section showing the throttle valve when in a fully open condition.
b is a cross-section showing the throttle valve when in the half open condition.
c is a cross-section showing the throttle valve when in a fully closed condition.
As is clear from
A piston rod 14 is extended from one end of the piston 13 in the direction of the axis line L, and the piston rod 14 is protruding outward while slidably penetrating the end cover 12. A numeral 15 denotes a sealing member attached to the end cover 12, for sealing a gap between the end cover 12 and an outer peripheral surface of the piston rod 14. In addition, at the other end of the piston 13, a sealing member 16 for interrupting between a first pressure chamber 18, described later, and a cushion chamber 20 when in a cushioning action is extended in the direction of the axis direction L. The sealing member 16 is integrally formed with the piston rod 14, and is formed by means of causing part of the piston rod 14 to be extended from the piston 13. The length of the sealing member 16 is short, and is in an extent of about one fourth of a hole-length of the cylinder hole 11, in an example of the illustration.
At both ends of the piston 13, two of the first and second pressure chambers, 18 and 19, for exerting the action of the fluid pressure to the piston 13 are formed. In the above, the first pressure chamber 18 is formed between the piston 13 and the end wall 10a, and is allowed to communicate with the cushion chamber 20 having a small diameter, which is formed at the end wall 10a. The first pressure chamber 18 is allowed to communicate with a first port 21 formed at a side surface of the cylinder body 10 through the cushion chamber 20. The throttle valve 3 is provided in a manner so as to intervene in a flow path that connects the first pressure chamber 18 and the cushion chamber 20 as described later in detail. On the other hand, the second pressure chamber 19 is formed between the piston 13 and the end cover 12, and is allowed to communicate with a rod insertion hole 23 formed in the end cover 12. The second pressure chamber 19 is allowed to communicate with a second port 22 formed at a side surface of the end cover 12 through the rod insertion hole 23.
Accordingly, when the second pressure chamber 19 is thrown open outward through the second port 22 from a movement condition shown in
Furthermore, when the piston 13 approaches an end of the stroke in the retreating stroke of the piston 13, as shown in
The cushion packing 25 is a lip-type seal having a one-way sealing function, and interrupts a flow of the fluid in the reverse direction, i.e., the flow that is directed from the first pressure chamber 18 to the cushion chamber 20 in a condition being in contact with an outer periphery of the sealing member 16, whereas the cushion packing 25 allows the flow in the forward direction, i.e., the flow that is directed from the cushion chamber 20 to the first pressure chamber 18. Accordingly, when the pressurized fluid is supplied from the first port 21 to the cushion chamber 20 at a time when the piston 13 is advanced from the movement condition shown in
The variable throttle valve 3 is attached to a side face of the cylinder body 10 and is constructed as follows. That is, as clear from
The valve hole 30 is composed of a small diameter hole portion 30a positioned at a backside of the valve hole 30 and a large diameter hole portion 30b positioned outside the valve hole 30. At a side face of the small diameter hole portion 30a, a first flow path hole 33 connected to the first pressure chamber 18 is opened, and at a center position of a bottom face of the small diameter hole portion 30a, a second flow path hole 34 connected to the cushion chamber 20 is opened.
On the other hand, the valve rod 31 is, as clear from
As a hooking device for hooking the valve rod 31 in the valve hole 30, a hooking member 38 composed of a ring-shaped stopping ring shown in
However, the hooking device is not limited to the member that is separately formed like the hooking member 38. For example, a construction in which a hooking groove in a circumferential direction is formed in an inner peripheral surface of the valve rod 30, and a projection formed on an outer periphery of the valve rod 31 is movably hooked on the hooking groove may be applicable.
In an inner part of the valve rod 31, a connecting hole 40 for connecting the first flow path hole 33 and the second flow path hole 34 is formed. A first hole opening 40a of one end of the connecting hole 40 is opened at a position between two sealing members, 41 and 41, at a side face of the main shaft portion 31a, and is capable of communicating with the first flow path hole 33. A second hole opening 40b of the other end of the connecting hole 40 is opened at a bottom face of the main shaft portion 31a and is allowed to constantly communicate with the second flow path hole 34.
Further, a flow adjusting groove 42 for adjusting a connected square measure of the first hole opening 40a of the connecting hole 40 and the first flow path hole 33 is formed on an outer peripheral surface of the main shaft portion 31a. The flow adjusting groove 42 extends in a circumferential direction around the outer peripheral surface of the main shaft portion 31a from a position of the first hole opening 40a as a base end, and the groove width gradually narrows toward the tip end side thereof while the groove depth gradually shallows at the same time between two of the sealing members, 41 and 41. Although a groove shape of the flow adjusting groove 42 is formed of a V-shaped cross-section in the drawing, other arbitrary cross-section shape, such as a U-shape, a concavity-shape, a trapezoid, or the like may be applicable.
The thus constructed variable throttle valve 3 adjusts the flow of the pressurized fluid by means of varying the connected square measure (valve opening extent) of the first hole opening 40a of the connecting hole 40 and the first flow path hole 33 upon rotating the valve rod 31. That is, as shown in FIG. 6a, when the first hole opening 40a and the first flowing path hole 33 are directly and perfectly allowed to communicate with each other, the throttle valve 3 is in a fully open condition and the flow is maximized. When the valve rod 31 is rotated clockwise as shown in
Although the valve rod 31 is configured to be held at an arbitrary operative position by means of friction force caused by getting crushed of two of the sealing members, 41 and 41, it may be configured to stop at a predetermined operative position by means of appropriate device other than the above.
Further, the valve rod 31 is preferable to be configured to contact a stopper or the like at the fully open position and the fully closed position so that the same cannot be rotated further.
An operating angle of the valve rod 31 from the fully open position to the fully closed position is determined according to a length in a circumferential direction of the flow adjusting groove 42. Although the operating angle in the illustrated example is about 180 degrees, the same can be set to be 180 degrees or less by means of shortening a length of the flow adjusting groove 42 shorter than the illustrated case and vice versa.
In this case, since the flow adjusting groove 42 is formed such that the groove width thereof gradually narrows toward the tip end side while the groove depth gradually shallows at the same time, in comparison with that only the groove depth gradually shallows while the groove width remains constant, a variation of the valve opening extent in relation to the operating angle of the valve rod 31 can be set to be large and the valve opening extent is adjusted with ease.
Thus, the flow of the fluid discharged through the throttle valve 3 can be adjusted by means of adjusting the valve opening extent while rotating the valve rod 31 of the variable throttle valve 3, and a moving speed of the piston 13 at a time when the cushioning action is created, can be controlled.
In addition, since the throttle valve 3 is constructed such that the flow is adjusted by means of only rotating the valve rod 31 around the axis line M in the valve hole 30, the variable throttle valve can be constructed at a compact and simple structure with small number of parts in comparison with the conventional variable throttle valve that advances and retreats the valve rod 31 in the direction of the axis line M, and the variable throttle valve can be compactly assembled in the fluid pressure cylinder.
Incidentally, in the illustrated embodiment, although the piston 13 is configured to stop at the end of the retreating stroke in the buffered manner by means of providing the throttle valve 3, the cushion chamber 20, and the sealing member 16 at a head side (a side of the end wall 10a) of the fluid pressure cylinder 2, the piston 13 can also be configured to stop at an end of the advancing stroke in the buffered manner by means of providing these throttle valve 3, the cushion chamber 20, and the sealing member 16 at a rod side (a side of the end cover 12). Alternatively, the cushioning action may be exerted to both ends of the stroke of the piston 13 by means of providing these throttle valve 3, the cushion chamber 20, and the sealing member 16, at both the head side and the rod side.
In addition, in a case that the cushion chamber and the sealing member are provided at the rod side, it is sufficient to attach the cushion packing 25 while causing the rod insertion hole 23 of the end cover 12 to serve as the cushion chamber, and is sufficient to attach a sleeve-shaped sealing member around an outer periphery of the piston rod 14.
Although the throttle valve 43 has substantially the same construction as the throttle valve 3 in the first embodiment, different from the case of the first embodiment, the first flow path hole 33 that opens at a side face of the valve hole 30 is allowed to communicated with a port 44, and the second flow path hole 34 that opens at a bottom face of the valve hole 30 is allowed to directly communicate with a pressure chamber 45. Further, the cushion chamber and the sealing member in the first embodiment are not provided.
Incidentally, although the second flow path hole 34 has the same size as that of the small diameter hole portion 30a of the valve hole 30, the same may be smaller than the small diameter hole portion 30a. Further, the port 44 may be located at a position indicated by a dashed line.
Since the construction of the second embodiment other than the above-described construction is the same as that of the first embodiment, the same numerals are attached to the same main portions as those in the first embodiment and explanations thereof are omitted.
In the cylinder apparatus 1B of the second embodiment, a flow of the pressurized fluid supplied from the port 44 to the pressure chamber 45, or discharged from the pressure chamber 45 to the port 44 is adjusted by means of the throttle valve 43, and the piston is driven in a reciprocating movement at a speed corresponding to the adjusted flow.
The throttle valve 43 can be provided at both of a head side and a rod side, or can be also provided either at the head side or at the rod side.
In the throttle valves, 3 and 43, of each of the embodiments, although the valve hole 30 and the valve rod 31 are provided with the large diameter portion and the small diameter portion, respectively, these valve hole 30 and the valve rod 31 may have a uniform diameter over an entire length thereof, as the third embodiment shown in
Incidentally, although the throttle valve 3 is used as a cushion valve in the first embodiment and the throttle valve 43 is used as a speed control valve in the second embodiment, both of the throttle valve 3 for the cushion and the throttle valve 43 for speed control can be provided in one fluid pressure cylinder 2 in a parallel manner.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-214656 | Jul 2005 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2556698 | Loewe | Jun 1951 | A |
| 2861769 | Schumann | Nov 1958 | A |
| 3231234 | Williamson | Jan 1966 | A |
| 3443793 | Hulsey | May 1969 | A |
| 6279451 | Hirano et al. | Aug 2001 | B1 |
| Number | Date | Country |
|---|---|---|
| 1351235 | May 2002 | CN |
| 1107809 | May 2003 | CN |
| 1201805 | Aug 2006 | EP |
| Number | Date | Country | |
|---|---|---|---|
| 20070017363 A1 | Jan 2007 | US |
