JP2001041323A - Water pressure type cylinder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water pressure type cylinder device reducing the slide resistance of a shaft sealing packing member and having excellent durability comparable to an oil pressure type cylinder device. SOLUTION: This device is provided with a piston rod 2 dividing the interior of a cylinder body 1 into two pressure chambers 7, 8. The piston rod 2 is moved in an extending direction by supplying water (actuating liquid) into the first pressure chamber 7, and is moved in a contracting direction by supplying water into the second pressure chamber 8. On the cylinder body 1, a penetrating hole 23 of a rod portion 6 is provided at a projecting side end part wherein the rod portion 6 is projected when the piston rod 2 is moved in the extending direction. A sliding bearing 24 slidably supporting the rod portion 6 and a shaft sealing packing member 25 preventing the leakage of water in the second pressure chamber 8 are provided in the penetrating hole 23. A lubricating water supplying means 30 is provided at the projecting side end part, which supplies lubricating water to the outer peripheral surface 6a of the rod portion 6 when the piston rod 2 is moved in the contracting direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic cylinder device capable of improving durability.

[0002]

2. Description of the Related Art Conventionally, hydraulic cylinder units have been used in various industrial fields. This type of cylinder device includes a piston rod slidably disposed inside a cylinder main body and defining the inside of the cylinder main body as two pressure chambers. The piston rod is moved in the extension direction by supplying the working fluid to one pressure chamber, and is moved in the shortening direction by supplying the working fluid to the other pressure chamber.

[0003] A through hole for a rod portion is formed in the cylinder body. The through hole is provided with a sliding bearing that slidably supports the rod portion and a shaft sealing packing member that prevents leakage of hydraulic fluid in the other pressure chamber. Oil is used as the working fluid.

[0004]

However, in this hydraulic cylinder device, since oil is used as the working fluid, it is difficult to treat the waste liquid and it is not environmentally friendly. As a cylinder device, development of a hydraulic cylinder device using water as a working fluid is desired.

[0005] If water is used instead of oil as the hydraulic fluid for a cylinder device of this type, the water has a lower viscosity than the oil, so that when the piston rod is moved in the extension direction, the rod of the piston rod moves. The water adhering to the outer periphery of the rod is peeled off by the shaft seal gasket, but the water film that wets the outer peripheral surface of the rod until immediately before the water is peeled off is lubricated by the contact surface between the shaft seal gasket and the rod. Therefore, the piston rod can move smoothly in the extension direction.

However, when the piston rod is to be moved in the shortening direction, the water film is peeled off by the shaft sealing packing member, and the rod portion whose outer peripheral surface is dry slides on the shaft sealing packing member, so that the cylinder body is moved. Because it is drawn inside, the sliding resistance of the contact surface between the shaft sealing packing member and the rod part increases, and if this is repeated many times,
The shaft sealing gasket member wears, causing water leakage, and there is a problem that the hydraulic cylinder device is inferior in durability to the hydraulic cylinder device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to reduce the sliding resistance of a shaft sealing packing member and to provide a hydraulic cylinder having excellent durability comparable to a hydraulic cylinder device. It is to provide a device.

[0008]

According to a first aspect of the present invention, there is provided a hydraulic cylinder device which is slidably disposed inside a cylinder body and which is provided inside the cylinder body. A piston rod defining two pressure chambers, the piston rod being moved in the extension direction by supplying water to one pressure chamber and moved in the shortening direction by supplying water to the other pressure chamber. The cylinder body is formed with a through hole through which a rod portion of the piston rod penetrates, and the through hole has a sliding bearing that slidably supports the rod portion and water from the other pressure chamber. A shaft sealing packing member for preventing leakage is provided, and when the piston rod is moved at least in the shortening direction in the cylinder body, the shaft portion of the rod portion located outside the shaft sealing packing is provided. Lubricant supplying means for supplying lubricating water to the peripheral surface and is characterized in that is provided.

According to the first aspect of the invention, when the piston rod is moved in the shortening direction and drawn into the cylinder body, the water film is peeled off when the piston rod moves in the extension direction. Since the lubricating water is supplied from the lubricating water supply means to the outer peripheral surface of the rod portion in a dry state, the sliding resistance of the contact surface between the shaft sealing packing member and the rod portion can be reduced, and thus the shaft sealing can be performed. As a result, the wear of the packing member can be reduced, and the durability equivalent to the hydraulic cylinder device can be obtained.

According to a second aspect of the present invention, in the hydraulic cylinder device according to the first aspect, a dust seal member is provided in the through hole outside the shaft seal packing member to prevent dust and dirt from being mixed. And the lubricating water supply means is arranged between the shaft sealing packing member and the dust seal member.

According to the second aspect of the present invention, when the piston rod is moved in the shortening direction, dust is removed by the dust seal member, and the rod portion slides on the shaft sealing packing member with the dust attached. To prevent the shaft seal from being damaged due to dust. Further, the lubricating water supplied by the lubricating water supply means is sealed by the dust seal member, and leakage of the lubricating water to the outside can be reduced.

According to a third aspect of the present invention, in the hydraulic cylinder device according to the second aspect, the dust seal member is provided with an annular lip portion for preventing lubricating water from leaking from the through hole. An annular lip portion is provided which has an annular lip portion for preventing the greeting from adhering to the outer peripheral surface of the rod portion and mixing into the inside of the cylinder body.

According to the third aspect of the present invention, it is possible to further prevent the lubricating water from flowing out of the through hole to the outside. Furthermore,
If the lubricating water supply part is set to the atmospheric pressure atmosphere, the annular lip part also becomes the atmospheric pressure, so the sealing performance under high pressure is not required, and the force with which the annular lip part presses the rod is small. Therefore, the frictional resistance is small and the wear can be reduced, and the degree of freedom in selecting the sealing material increases.

According to a fourth aspect of the present invention, in the hydraulic cylinder device according to any one of the first to third aspects, the lubricating water supply means constantly wets the outer peripheral surface of the rod portion. For storing lubricating water. According to the present invention, the lubricating water supply means can be formed with a simple structure.

According to a fifth aspect of the present invention, in the hydraulic cylinder device according to any one of the first to fourth aspects, the lubricating water supply means constantly wets the outer peripheral surface of the rod portion. And a supply passage for supplying running water. According to the invention as set forth in claim 5, heat generated by friction between the shaft sealing packing member and the rod portion can be received and removed by running water, so that the cooling effect of the rod portion can be improved, and the shaft can be improved. A decrease in the durability of the sealing packing member can be suppressed.

According to a sixth aspect of the present invention, in the hydraulic cylinder device according to any one of the first to fifth aspects, an injection for spraying lubricating water toward an outer peripheral surface of the rod portion is provided. It has a part.
According to the present invention, a small amount of lubricating water can be supplied to the rod portion, and the risk of lubricating water flowing out from the through hole to the outside can be reduced.

According to a seventh aspect of the present invention, in the hydraulic cylinder device according to the fourth or fifth aspect, the bearing member comprises a first bearing member and a second bearing member. The bearing member and the second bearing member are arranged at an interval with the bearing seal member interposed therebetween, and the second bearing member is disposed between the bearing seal member and the dust seal member. It is characterized by having. According to the present invention, since the distance between the two bearings can be increased, the piston rod can be firmly supported, thereby preventing shaft runout, and thus reducing uneven wear of the shaft seal packing member.

According to an eighth aspect of the present invention, in the hydraulic cylinder device according to any one of the first to seventh aspects, water is supplied to and discharged from the other pressure chamber in the cylinder body. A supply / discharge port is provided, and the supply / discharge port and the other pressure chamber are communicated with each other by an annular communication path extending along the rod portion, and the piston rod is moved when the piston rod is moved in the extension direction. A large-diameter fitting portion that fits into the annular communication passage is formed, and the cylinder body includes:
A cushion passage is formed to communicate the supply / discharge port and the other pressure chamber through a throttle valve to perform a cushioning operation, and the cylinder body communicates with the annular passage and the other pressure chamber. , A cushion seal member is provided at a portion facing the, and the cushion seal member and the large-diameter fitting portion engage to close the annular passage portion. According to the invention described in claim 8, the annular communication passage is closed by the cushion seal member and the large-diameter fitting portion, so that the outflow of water is prevented. Since water is restricted and discharged through the throttle valve, the impact force at the end of movement of the piston rod in the extension direction can be absorbed.

According to a ninth aspect of the present invention, in the hydraulic cylinder device according to the eighth aspect, the cushion seal member is made of ultra-high molecular weight polyethylene. According to the ninth aspect of the present invention, since ultra-high molecular weight polyethylene is used as the material of the cushion seal member, it can withstand a sudden increase in pressure generated during the cushion action. Further, even when sliding with the large-diameter fitting portion, wear is small. Therefore, the durability is further improved.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hydraulic cylinder device according to the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional view of a hydraulic cylinder device according to the present invention, showing a state in which a piston rod is moved in a shortening direction and stopped at an end of its movement, and FIG.
FIG. 3 is an enlarged sectional view of the cushion seal member shown in FIG.
FIG. 4 is an enlarged sectional view of the dust seal member shown in FIG. 1, and FIG. 4 is a longitudinal sectional view of the hydraulic cylinder device according to the present invention, in which the piston rod has been moved in the extension direction and has reached the vicinity of the end of movement. Is shown.

In FIG. 1, reference numeral 1 denotes a cylinder body, and reference numeral 2 denotes a piston rod. The piston rod 2 is slidably disposed inside the cylinder body 1. The cylinder body 1 has a cylinder tube, a head cover member 3, and a rod cover member 4, and one end of the cylinder tube is closed by the head cover member 3,
The other end is closed by a rod cover member 4 as a projecting end from which the rod projects.

The piston rod 2 comprises a piston part 5 and a rod part 6. The inside of the cylinder body 1
The piston section 5 defines two pressure chambers 7 and 8. A seal ring member 5b and bearings 5a and 5c are fitted to the piston portion 5.

The head cover member 3 has one pressure chamber 7
A supply / discharge port 9 for supplying / discharging the working fluid is formed at the bottom. The rod cover member 4 has a supply / discharge port 10 for supplying / discharging the working fluid to / from the other pressure chamber 8. The working fluid is water. As the water, pure water, tap water, river or pond water, high water content and the like are used. The head cover member 3 includes
An annular communication passage 11 communicating the pressure chamber 7 and the supply / discharge port 9 is provided along the direction in which the piston rod 2 extends. Further, the rod cover member 4 is provided with an annular communication passage 12 communicating the pressure chamber 8 and the supply / discharge port 10 along the direction in which the piston rod 2 extends.

The piston rod 2 is moved in the extension direction (arrow A1 direction) by supplying water to the pressure chamber 7,
In addition, by supplying water to the pressure chamber 8, the pressure chamber 8 is moved in the shortening direction (the direction of the arrow A2).

The piston rod 2 has a large-diameter fitting portion 13 formed integrally with the piston portion 5 for fitting into the annular communication passage 11 and closing the annular communication passage 11 when the piston rod 2 is moved in the shortening direction. At the same time, the large-diameter fitting portion 14 that fits into the annular communication passage 12 when closed in the extension direction and closes the annular communication passage 12 is integrated with the piston portion 5 on the side opposite to the large-diameter fitting portion 13. Is formed.

A throttle valve 15 is provided on the head cover member 3. The throttle valve 15 has an orifice passage 16. The head cover member 3 is formed with a cushion passage 17 that communicates the pressure chamber 7 and the supply / discharge port 9 via a throttle valve 15 to perform a cushion function.

A throttle valve 18 is provided on the rod cover member 4. The throttle valve 18 has an orifice passage 19. A cushion passage 20 is formed in the rod cover member 4 to communicate the pressure chamber 8 and the supply / discharge port 10 via a throttle valve 18 to perform a cushioning action.
A cushion seal member 21 is provided in the enlarged diameter hole 12a of the annular communication passage 12 facing the pressure chamber 8 at the end of movement of the piston rod 2 in the extension direction.

As shown in FIG.
As shown in the enlarged view, radial grooves 21a extending radially in the radial direction are formed on all sides (three places appear in FIG. 2 and the other one is formed at a position not appearing in the drawing on the near side). Ring-shaped body. This ring-shaped body is cut at one place, and the ring-shaped body can be opened and mounted at the cut portion when mounting. Reference numeral 35 indicates the cut portion. As shown in FIG. 4, when the piston rod 2 is moved in the extension direction, the large-diameter portion 14 is fitted to the cushion seal member 21 in the vicinity of the end of movement in the extension direction. 12 is closed, the water in the pressure chamber 8 is throttled by the throttle valve 18 via the cushion passage 20 as shown by arrows B1 and B2, and flows toward the supply / discharge port 10 as shown by arrow B3. To flow. Therefore, the impact force at the end of movement of the piston rod 2 in the extension direction is reduced.

The material of the cushion seal member 20 is made of ultra-high molecular weight polyethylene that can withstand a sudden increase in pressure generated during the cushion action. The orifice areas of the throttle valves 15 and 18 can be adjusted. By operating the throttle valves 15 and 18, the cushioning force at the end of movement of the piston rod 2 can be adjusted.

The rod cover member 4 has a through hole 23 through which the rod portion 6 passes. A sliding bearing member 24 slidably supporting the rod portion 6 is provided in the through hole 23.
Seal member 25 for preventing water from leaking from pressure chamber 8 and pressure chamber 8
Are provided.

The shaft sealing packing member 25 includes a buffer ring 26 and a rod packing member 27. The buffer ring 26 and the rod packing member 27 are provided close to each other in the direction in which the rod portion 5 extends. The buffering 26 plays a role in reducing the pressure in the pressure chamber 8 to the atmospheric pressure. The rod packing member 27 serves to prevent the water leaking from the buffering 26 from leaking to the outside.

The sliding bearing 24 is provided with a first bearing member 28 which is disposed at intervals in the direction in which the piston rod 2 extends.
And a second bearing member 29. The shaft seal member 25 is located between the first bearing member 28 and the second bearing member 29. Thereby, both bearings 28, 29
Since the interval between them can be made large, the piston rod 2 can be firmly supported, so that the shaft runout during the reciprocation of the piston rod 2 is prevented.

The rod cover member 4 includes an outer periphery of the rod portion 6 near the rod packing member 27 between the rod packing member 27 and the second bearing member 29 when the piston rod 2 is moved at least in the shortening direction. A storage chamber 30 is provided as lubricating water supply means for supplying lubricating water to the surface 6a. Water can be supplied to the storage chamber 30 from a water supply port 31 and water can be discharged from a drain port 32.

A water supply hose (not shown) as a lubricating water supply passage is connected to the water supply port 31, and the water supply port 31 is connected to the storage chamber 30.
Water may be constantly flowed toward the water. If the water is constantly flowed and lubricated, the heat generated by the friction between the shaft sealing packing member 25 and the rod portion 6 may be received by the running water and removed. Therefore, the cooling effect of the rod portion 6 can be improved.

Instead of flowing water from the water supply port 31 toward the storage chamber 30, a small amount of lubricating water is sprayed on the outer peripheral surface 6a of the rod portion 6 only when the piston rod 2 is moved in the shortening direction. An injection unit not shown may be provided.

The rod cover member 4 is provided with a dust seal member 33 for preventing dust and dirt from being mixed, on the projecting side of the rod portion 5 beyond the second bearing member 29. The dust seal member 33 has an annular lip portion 33a for preventing lubricating water from leaking from the through hole 23 and dust adhere to the outer peripheral surface 6a of the rod portion 6 as shown in an enlarged view in FIG.
Has a double lip structure with an annular lip portion 33b for preventing the lip from entering the inside. Since the storage chamber 30 is placed under the atmospheric pressure, the dust seal member 33 is loosely in contact with the rod portion 6. Thereby, the frictional resistance with the rod portion 6 is reduced. In FIG.
Indicates a backup ring, and the backup ring 3
6 is for pressing the dust seal member 33 against the surface of the piston rod 2.

According to the above embodiment, when the piston rod 2 is moved in the shortening direction and drawn into the cylinder body 1, the water film is peeled off when the piston rod moves in the extending direction. Rod part 6 in a dry state
Lubricating water is supplied from the storage chamber 30 to the outer peripheral surface of
The sliding resistance of the contact surface between the shaft seal packing member 25 and the piston rod 2 can be reduced, and the wear of the shaft seal packing member 25 can be reduced, and the durability equivalent to the hydraulic cylinder device can be obtained. Can be.

The present inventors have confirmed that the sum of the repeated sliding distances of the piston rod 2 in the hydraulic cylinder device according to the above-mentioned embodiment has been greatly increased.

According to the above embodiment, even if water leaks from the rod packing member 27, the water discharge port 32 is discharged from the storage chamber 30, so that the dust seal member 33 is required. The sealing ability can be further reduced.

Further, the same lubricating water and water supplied to the two pressure chambers can be used, and can be supplied from the same water pressure source.

[0041]

According to the present invention, when the piston rod is moved in the shortening direction and drawn into the cylinder body, the water film is peeled off and dried when the piston rod moves in the extending direction. Since the lubricating water is supplied from the lubricating water supply means to the outer peripheral surface of the rod portion in the state, the sliding resistance of the contact surface between the shaft sealing packing member and the rod portion can be reduced, and thus the shaft sealing packing member. Wear can be reduced, and durability comparable to a hydraulic cylinder device can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a hydraulic cylinder device according to the present invention, showing a state in which a piston rod is moved in a shortening direction and stopped at an end of its movement.

FIG. 2 is a cross-sectional plan view of the cushion seal member shown in FIG.

FIG. 3 is a cross-sectional view of the dust seal member shown in FIG.

FIG. 4 is a longitudinal sectional view of the hydraulic cylinder device according to the present invention, showing a state where the piston rod has been moved in the extension direction and has reached the vicinity of the end of movement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder main body 2 Piston rod 4 Rod cover member 5 Piston part 6 Rod part 6a Outer peripheral surface 7, 8 Pressure chamber 13, 14 Large diameter fitting part 20 Cushion passage 21 Cushion seal member 23 Through hole 24 Sliding bearing 25 Shaft seal packing Member 26 Buffering 27 Rod packing member 28 First bearing member 29 Second bearing member 30 Storage chamber (lubricating water supply means)

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Masaru Kubota 7-3-3 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo F-term in Nabco Integrated Technology Center (reference) 3H081 AA03 BB05 CC24 EE04 EE07 EE09 EE15 EE18 3J043 AA12 AA13 BA05 CA02 CB13 DA01 HA01 3J044 AA12 CC14 CC30 DA10

Claims (9)

[Claims] A piston rod slidably disposed within a cylinder body to define the interior of the cylinder body into two pressure chambers, the piston rod supplying water to one of the pressure chambers. The piston body is moved in the extension direction and is moved in the shortening direction by supplying water to the other pressure chamber.The cylinder body has a through hole through which the rod portion of the piston rod penetrates. A sliding bearing slidably supporting the rod portion and a shaft sealing packing member for preventing leakage of water from the other pressure chamber are provided, and the piston rod is moved at least in a shortening direction on the cylinder body. A hydraulic cylinder device provided with a lubricating water supply means for supplying lubricating water to an outer peripheral surface of the rod portion located outside the shaft sealing gasket when the lubricating water is supplied. 2. A dust seal member according to claim 1, wherein said through hole is provided with a dust seal member for preventing dust and dirt from entering outside said shaft seal packing member, and said lubricating water supply means is provided between said shaft seal packing member and said dust seal member. And a hydraulic cylinder device. 3. The cylinder body according to claim 2, wherein the dust seal member has an annular lip portion for preventing lubricating water from leaking from the through hole, and dust adheres to an outer peripheral surface of the rod portion. A hydraulic cylinder device having a double lip structure including an annular lip portion for preventing mixing into the inside. 4. The hydraulic system according to claim 1, wherein said lubricating water supply means has a storage chamber for storing lubricating water to constantly wet an outer peripheral surface of said rod portion. Cylinder device. 5. A hydraulic cylinder according to claim 1, wherein said lubricating water supply means has a supply passage for supplying running water to constantly wet the outer peripheral surface of said rod portion. apparatus. 6. The hydraulic cylinder device according to claim 1, further comprising an injection unit that sprays lubricating water toward an outer peripheral surface of the rod unit. 7. The bearing member according to claim 4, wherein the bearing member includes a first bearing member and a second bearing member, and the first bearing member and the second bearing member sandwich the bearing seal member therebetween. Along with being arranged at intervals,
The hydraulic cylinder device, wherein the second bearing member is disposed between the shaft sealing packing member and the dust seal member. 8. The cylinder body according to claim 1, further comprising a supply / discharge port for supplying / discharging water to / from the other pressure chamber in the cylinder body. The pressure chamber communicates with an annular communication passage extending along the rod portion, and the piston rod is formed with a large-diameter fitting portion that fits into the annular communication passage when moved in the extension direction. In the cylinder body, a cushion passage is formed to communicate the supply / discharge port and the other pressure chamber through a throttle valve to perform a cushioning action, and the cylinder body is connected to the annular communication passage continuously. A hydraulic cylinder device, wherein a cushion seal member is provided in a portion facing the other pressure chamber, and the cushion seal member and the large-diameter fitting portion engage to close the annular communication passage. 9. The hydraulic cylinder device according to claim 8, wherein said cushion seal member is made of ultra-high molecular weight polyethylene.