WO1999042741A1

WO1999042741A1 - Gas spring

Info

Publication number: WO1999042741A1
Application number: PCT/JP1998/000699
Authority: WO
Inventors: Ichiro Kitaura
Original assignee: Pascal Kabushiki Kaisha
Priority date: 1998-02-18
Filing date: 1998-02-18
Publication date: 1999-08-26

Abstract

A gas spring (1) comprises, among other things, a cylinder body (2), a piston member (3), compressed gas filled in a gas operating chamber (4), lubricating oil (4a) accommodated in the bottom part of the gas operating chamber (4), a base member (5) fixed to the output end part of the piston member (3), a guiding cylindrical member (6) fixed to the upper face of the base member (5) and extending upward, with the guiding cylindrical member (6) having an annular guide hole (23) for guiding the cylinder body (2) toward the outside of the piston member (3), wherein the cylinder body (2) and the piston member (3) are arranged in an upside down state in a perpendicular attitude, and the oil (4a) is reliably supplied to sliding parts (21) between the cylinder body (2) and the piston member (3), thereby improving the performance of sealing the sliding parts (21) with the oil (4a).

Description

Description Gas spring Technical field

The present invention relates to a gas spring suitable for applying a cushioning force to a mold of a press device, displacing the mold, and ejecting the mold, and relates to a biston member and a cylinder body. To improve the lubricating performance of lubricating the sliding parts, and to reduce the size and simplify the structure.

Background art

The gas spring fills a gas working chamber defined by the cylinder body, the piston member, and the cylinder body and the piston member, and supplies a compressed gas (for example, a compressed nitrogen gas) that urges the biston member in the advance direction. Have. The piston member includes a piston portion and a rod portion having a smaller diameter than that of the piston member (a normal piston member), and a piston member configured in a rod shape so that the rod portion functions as a piston portion. (Mouth type button member), etc. are applied.

In a gas spring that uses a normal biston member, the piston part is slidably mounted in the cylinder hole of the cylinder body, and the outer periphery of the piston part is impregnated with packing and oil to seal compressed gas. An annular fiber material is attached. In a gas spring using a head-type piston element, a packing for sealing compressed gas and an annular fiber material impregnated with oil are attached to the peripheral wall of the head hole of the cylinder. I have.

The oil for lubrication is supplied little by little to the sliding part between the biston member and the cylinder body from the annular fiber material, and while the gas spring is used tens of thousands of times, the oil of the fiber material is removed. And the lubrication of the sliding parts becomes incomplete. As a result, the packing and the sliding portion are worn, the sealing performance of the packing is reduced, the compressed gas leaks easily, and the performance of the gas spring is reduced. If the gas pressure of the compressed gas falls below the set value, stop the press device and refill the gas spring with the compressed gas. There is a need. Thus, the durability of the gas spring depends on the lubricating performance of lubricating the sliding portion between the piston element and the cylinder body.

Conventionally, various techniques for improving the lubrication performance of a gas spring have been proposed. For example, in the die cylinder (gas spring) of U.S. Pat. No. 4,691,902, the cylinder body is arranged in a normal posture which is not an inverted posture, and a rod portion of a normal type piston member is provided at an upper end of the cylinder body. The piston extends upward through the through hole in the wall, the piston is slidably inserted into the cylinder hole, and the outside of the cylinder hole in the cylinder body is for compressed gas. A reservoir is formed, an oil reservoir for storing oil is formed at a lower portion of the gas working chamber, and a rising pipe leading to an oil inlet at the bottom of the oil reservoir is extended into the reservoir. The oil in the oil reservoir is pushed up into the riser pipe when the piston member moves in and out, and the mist between the oil in the riser pipe and the compressed gas enters the cylinder hole from the oil inlet when the piston member moves out. It is designed to be injected. In this die cylinder, a reservoir, a start-up pipe, an oil reservoir, and the like are required to inject the oil mist, so that the size of the die cylinder is increased and the structure is complicated.

In the die cylinder disclosed in U.S. Pat. No. 4,688,775, a cylinder body having a normal posture and a normal piston member are applied, and a reservoir and an oil supply system are provided outside the die cylinder. Oil mist is automatically injected into the cylinder hole when the member moves forward. In this die cylinder, the peripheral equipment including the reservoir and the oil supply system becomes large and complicated, which is disadvantageous in terms of manufacturing cost. On the other hand, the following dylinda is also known. In a die cylinder to which a normal piston member is applied, an annular fiber material impregnated with oil is attached to the outer periphery of the piston part, and a thin oil supply hole formed inside the piston member is impregnated with oil. The fibrous material is attached, and oil is supplied from the fibrous material to the annular fibrous material. When the oil in the string-like fiber material becomes low, the plug at the tip of the mouth portion of the piston member can be removed to replenish the oil. However, since the cord-like fiber material is a cord-like relatively thin material, it is difficult to increase the amount of oil that can be impregnated. Conventionally, the gas spring is usually not in the inverted position, Although it is used in a normal posture located on the side, it is also known in the art to use the gas spring in an inverted posture.

By the way, gas springs using a head-type piston element are advantageous in terms of manufacturing cost, but since the piston element is guided only through the hole in the cylinder body, the piston element is The eccentric operation is applied to the cylinder body, and the piston member, the peripheral surface of the rod insertion hole and the packing are liable to be unevenly worn, and the uneven wear causes the compressed gas to leak easily. In addition, since the dust adhering to the piston member easily invades the sliding portion, the uneven wear and abrasion are further generated.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the lubrication performance of lubricating a sliding part between a piston element and a cylinder body in a gas spring, while miniaturizing and simplifying the structure for the lubrication. To improve the guide performance to guide the member so that it does not operate eccentrically, to improve the dustproof performance for the piston member, to ensure that the maximum stroke of the biston member with respect to the cylinder body can be limited, etc. It is.

Disclosure of the invention

The gas spring according to the present invention is movably mounted on the cylinder body through a cylinder body disposed in an upright position in a vertical posture and a rod hole formed in a lower end wall of the cylinder body. A piston member, a compressed gas filled in a gas working chamber defined by the cylinder body and the piston member, and biasing the piston member toward the advance side; and a sliding portion between the cylinder body and the piston member. Oil contained in a gas working chamber for lubrication, a base member fixed to an output end on a lower end side of the biston member, and an outer portion of the biston member fixed or integrally formed with the base member A guide cylinder member for forming an annular guide hole for guiding the cylinder body, and a straw for limiting the maximum stroke of the biston member so that the biston member does not come off from the cylinder body. A lock restriction mechanism.

The operation of the gas spring will be described. The piston member is urged toward the advance side with respect to the cylinder body by the compressed gas (for example, compressed nitrogen gas) filled in the gas working chamber, so that the gas spring functions as a gas spring. Has become. When applying a piston member having a piston portion and a rod portion having a smaller diameter than the piston member, the gas working chamber is formed above the piston portion, and the oil accommodated in the gas working chamber is provided in the piston portion. And is supplied to the sliding part between the piston and the cylinder body.

On the other hand, when a rod-shaped piston element whose mouth part functions as a piston element is applied, the piston element is guided by the peripheral surface of the rod hole in the lower end wall of the cylinder body. The piston member slides on the peripheral surface of the through hole. Since the cylinder body is installed upright in a vertical position, the oil contained in the gas working chamber is reliably supplied to the sliding part between the piston element and the cylinder body, and the sliding part is reliably lubricated. You.

On the other hand, in order to prevent the biston member from eccentrically operating with respect to the cylinder body, a base member is fixed to an output end on the lower end side of the biston member, and a guide fixed or integrally formed on the base member. The cylindrical member has an annular guide hole formed outside the biston member for guiding the cylinder body. -Therefore, when the piston member moves forward and backward with respect to the cylinder body, the cylinder body is guided by the guide hole, the cylinder body and the biston member are maintained in parallel, and uneven wear of the sliding part occurs. The sealing performance of sealing the compressed gas can be secured.

In addition, since the outside of the piston member is covered with the cylinder body, the guide cylinder member, and the base member, the dustproof performance of dustproofing the piston member is significantly improved. Since the maximum stroke of the piston member is limited by the stroke limiting mechanism, the piston member does not come off from the cylinder body.

Further, since the base member fixed to the output end on the lower end side of the biston member is provided, the base member can be used for assembling and fixing the gas spring in the mold of the press device or the like.

Here, a gas passage for filling compressed gas may be formed in the base member and the biston member. In this case, a gas spring is connected to the gas passage with a compressed gas supply system (piping or hose) connected thereto. Can be used.

The piston member includes a piston portion and a rod portion having a smaller diameter than the piston portion. The troke restricting mechanism may be constituted by the piston part and the lower end wall of the cylinder body. The piston element may be formed in a rod shape so that the mouth part functions as a piston element. In this case, the guide hole is formed as a cylindrical hole, and the stroke limiting mechanism is constituted by a locking portion formed at an upper end portion of the piston member and a lower end wall portion of the cylinder body. Is also good. Alternatively, the stroke limiting mechanism may include an annular flange formed at a lower end of the cylinder body, and an upper end of a guide cylinder member slidable on the cylinder body in a direction opposite to the flange. And an annular locking portion formed so as to be fitted to the outside.

Further, a configuration may be adopted in which the guide cylinder member in the gas spring is omitted, and a plurality of mounting bolt holes are formed in the base member. Also in this configuration, a gas passage for filling the compressed gas may be formed in the base member and the piston member. In the case of a gas spring used in a state of being attached to a mold, the base member may be omitted and the guide cylinder member may be fixed to the mold. Also in this configuration, a gas passage for filling compressed gas may be formed in the piston member.

Further, another gas spring according to the present invention is movably mounted to the cylinder body through a cylinder main body and a rod hole formed in an upper end wall or a lower end wall of the cylinder main body. A piston member having a piston portion and a mouth portion having a smaller diameter than the piston member, and a piston member which is filled in a gas working chamber defined by the cylinder body and the piston portion. And a wheel storage chamber that is formed in the piston member and stores oil to be supplied to a sliding portion between the cylinder body and the piston part.

In this gas spring, the cylinder body and the piston member may be arranged in an inverted posture, or may be arranged in a normal posture other than the inverted posture. Since the piston member is urged toward the advance side by the compressed gas filled in the gas working chamber, it functions as a gas spring. Here, oil that is formed in the piston member and is supplied to the sliding portion between the cylinder body and the piston part is stored in the oil storage chamber, and the oil in the oil storage chamber slides when the piston member moves forward and backward. It is supplied to the moving part. Oil storage room Since the oil is stored in a large amount, it is possible to store a large amount of oil, so there is no need to replenish the oil over a long period of time. It is desirable that the oil storage chamber be replenished with oil when the oil storage chamber runs out of oil.

In this gas spring, an oil-impregnable annular fiber material is mounted in an annular groove in the outer peripheral portion of the piston portion, and an oil-impregnated replenishing fiber material is provided in the oil storage chamber from the top to the bottom. The oil in the oil storage chamber may be supplied to the annular fiber material through the use fiber material.

In such a configuration, even when the oil in the oil storage chamber is reduced, the gas spring can be used in the normal posture, in the inverted posture, or when the gas spring is used in the inverted posture. Since the oil is reliably supplied to the annular fiber material via the supply fiber material, the oil can be reliably supplied to the sliding portion.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a longitudinal sectional view of a gas spring according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line 111 of FIG. 1, and FIG. 3 is a longitudinal sectional view of a gas spring according to a first modification. FIG. 4 is a longitudinal sectional view of the gas spring according to the modified example 2, FIG. 5 is a longitudinal sectional view of the gas spring according to the modified example 3, and FIG. 6 is a sectional view taken along line VI-VI of FIG. FIG. 7 is a longitudinal sectional view of a gas spring and a main part of a mold according to Modification 4, FIG. 8 is a longitudinal sectional view of a gas spring according to Modification 5, and FIG. 9 is a longitudinal section of a gas spring according to another embodiment. FIG. 10 is a perspective view of the gas spring of FIG. 9 before the cylindrical body is bent into a cylindrical shape.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the gas spring 1 is generally called a die cylinder. The gas spring 1 is incorporated in a die of a press device to apply a cushion force to the die or to displace the die. It is suitable for ejecting a mold. The gas spring 1 is provided with a compressed gas (for example, 1.0 to 3) filled in a gas working chamber 4 defined by a cylinder body 2, a piston member 3, and a cylinder body 2 and a piston member 3. Nitrogen gas compressed to 0 MPa) and moisture contained in gas working chamber 4 It has a lubricating oil 4 a, a base member 5, a guide cylinder member 6, a stroke restricting mechanism 7 for restricting a maximum stroke of the piston member 3, and the like. The cylinder main body 2 is disposed in an upright position in a vertical posture, and the cylinder main body 2 has an upper wall member 2 b airtightly screwed onto an upper end side of a cylindrical body 2 a forming a cylinder hole 8. It has a structure in which an annular lower end wall 2c is fitted and fixed to the lower end of the body 2a. In addition, seal 9 10 for compressed gas sealing, stop ring 11 made of metal, sealing member 12, gas passage 13 for filling compressed gas, and the end of the gas passage 13 are closed. A plug 14 is also provided.

A rod-shaped through hole 15 having a circular cross section is formed in the center of the lower end wall 2c, and a packing groove, an oil groove, and a seal groove are formed in the peripheral wall of the rod insertion hole 15. Packing 16a and backup packing 16b are installed in the groove, oil-impregnated annular fiber material 17 is installed in the oil groove, and dust seal 18 is installed in the seal groove. Have been.

The piston member 3 is formed in the shape of a mouth so that the mouth portion 3a functions as a piston portion, and the upper end of the piston member 3 has a larger diameter than the rod portion 3a. An annular locking portion 19 is formed. The piston member 3 is formed with a concave hole 20 recessed from the upper end thereof and constituting a part of the gas working chamber 4. The filling amount of the compressed gas can be increased by the volume of the concave hole 20. The piston member 3 is slidably inserted into the rod through hole 15 and is mounted on the cylinder body 2 movably in the vertical direction.

In order to lubricate the sliding portion 21 between the cylinder body 2 and the piston member 3 (that is, the portion corresponding to the peripheral surface of the opening 揷 15), a predetermined amount is provided at the bottom of the gas working chamber 4. The oil 4a is strong and is contained to a level not exceeding the lock 19.

A base member 5 that is orthogonal to the biston member 3 is fixed to an output end on the lower end side of the biston member 3 with a bolt 22. A guide cylinder member 6 forming an annular guide hole 23 for guiding the cylinder body 2 is fixed outside the cylinder.

As shown in FIG. 2, the base member 5 has a square shape in plan view, and the guide tube member 6 The outer shape of the guide member is a square having the same shape as that of the base member 5, and the guide tube member 6 is fixed to the base member 5 by four bolts 26 at four corners. The peripheral surface of the guide hole 23 has a cylindrical shape, and the guide hole 23 also has a thick cylindrical shape. A dust seal 24 is mounted in an annular groove at an inner peripheral portion of an upper end portion of the guide tube member 6, and a breathing hole 25 is formed in a lower end portion of the guide tube member 6.

When the piston member 3 moves forward and backward relative to the cylinder body 2, the cylindrical body 2a of the cylinder body 2 and the lower end wall 2c are slidably fitted in the guide holes 23, The biston member 3 and the cylinder body 2 are guided so as to relatively move in parallel. Therefore, the sliding part 21 between the cylinder body 2 and the piston member 3 does not wear unevenly, and the gas sealing performance can be prevented from lowering. The stroke limiting mechanism 7 for limiting the maximum stroke of the piston member 3 so that the piston member 3 does not come off from the cylinder body 2 includes a locking portion 19 at the upper end of the piston member 3 and a lower end wall 2. c. The base member 5 may be formed with a plurality of mounting portions that are expanded outward from the guide cylinder member 6, and the mounting portions may be formed with mounting bolt holes. The base member 5 and the guide cylinder member 6 may be integrally formed, and their outer shapes may be cylindrical. Next, the operation of the gas spring 1 described above will be described.

When the piston member 3 retreats with respect to the cylinder body 2 due to a large load acting on the gas pressure of the compressed gas, the oil 4 a in the gas working chamber 4 adheres to the peripheral surface of the piston member 3. Most of the oil attached to the peripheral surface of the piston member 3 is wiped off by the packings 16a and 16b when the piston member 3 is advanced from the cylinder body 2, and the peripheral surface of the piston member 3 is covered with oil. The sliding part 21 is sufficiently lubricated because the biston member 3 advances in a state in which is formed. Moreover, oil is also applied to the peripheral surface of the piston member 3 from the annular fiber material 17. In this way, the lubricating performance for lubricating the sliding part 21 of the gas spring 1 between the cylinder body 2 and the piston member 3 is sufficiently enhanced, and the structure for lubricating the sliding part 21 is simplified and compact. Be transformed into

Since the oil 4a in the gas working chamber 4 functions to seal the sliding portion 21, the gas sealing performance can be significantly improved. When the piston member 3 moves in and out, the guide action of the guide hole 23 of the guide cylinder member 6 enables Since the solder body 2 and the piston member 3 move relative to each other while maintaining a parallel state, the sliding portion 21 does not wear unevenly, and the gas sealing performance can be maintained.

Since the outside of the piston member 3 is surrounded by the cylinder body 2, the guide cylinder member 6 and the base member 5, dust does not adhere to the piston member 3, and the piston member 3 and the sliding due to dust are prevented. The wear of the part 21 can be prevented. In this way, it is possible to prevent the compressed gas from leaking, prevent the cushioning force from being reduced due to the compressed gas leak, and increase the durability of the gas spring 1.

In addition, since the stroke limit mechanism 7 limits the maximum stroke of the piston member 3, the piston member 3 does not come off the cylinder body 2. The length and diameter of the cylinder body 2 and the biston member 3 may be various values as in the case of a normal gas spring, and the illustrated gas spring 1 is merely an example.

Next, a modified example in which the above-described embodiment is partially modified will be described. However, the same components as those of the above-described embodiment or the preceding modified embodiment are denoted by the same reference numerals, and description thereof is omitted.

1] Modification 1 (see Fig. 3)

As shown in FIG. 3, in this gas spring 1A, the piston member 3A has a piston portion 3b and a mouth portion 3a having a smaller diameter, and the piston portion 3b has a cylinder hole 8a. The rod portion 3 a is slidably inserted into the rod hole 15, and the piston member 3 A is movably mounted on the cylinder body 2. A packing 30a and a backup packing 30b are mounted in a packing groove on an outer peripheral portion of the biston portion 3b, and an annular fiber material 31 impregnated with oil is mounted in the oil groove. The gas working chamber 4 is defined by the cylinder body 2 and the piston part 3b. In addition to the compressed gas, the gas working chamber 4 has a sliding part 21A between the piston part 3b and the cylinder body 2. Oil 4a for lubrication is stored and accumulates on the upper surface side of the piston part 3b. The lower chamber 33 on the lower side of the piston portion 3b of the cylinder hole 8 is communicated with the atmosphere by a groove 34a for breathing and a small hole 34. In the gas spring 1A, the piston portion 3b and the lower end wall portion 2c constitute a stroke limiting mechanism 7A. In this gas spring 1A, basically the same operation as the gas spring 1 is performed. The effect is obtained. The oil 4a is reliably supplied to the sliding portion 21A between the cylinder body 2 and the piston member 3A, so the lubrication performance can be improved and the gas sealing performance can be improved by the oil 4a. Can be.

In order to increase the volume of the gas working chamber 4, a recess similar to the recess 20 is formed in the piston 3b and the rod 3a, and the oil 4a flows into the recess. The cylindrical portion for preventing the air pressure may be formed integrally with the upper end of the piston portion 3b.

2] Modification 2 (see Fig. 4)

As shown in FIG. 4, in this gas spring 1B, the piston member 3B is formed in a mouth shape, the locking portion 19 is omitted, and the structure of the piston member 3B is simplified. ing. An annular flange 2d whose diameter is increased outward is formed on the outer periphery of the lower end of the cylinder body 2B. An annular engaging portion 6a is formed at the upper end of the guide cylinder member 6B so as to face the flange portion 2d and slidably fit on the cylindrical body 2a of the cylinder body 2B. I have. An annular guide hole 23B for guiding the cylinder body 2B slidably is formed outside the piston member 3B by the guide cylinder member 6B, and a piston member is formed with respect to the cylinder body 2B. When 3B moves relatively forward and backward, the cylinder body 2B is guided by the piston member 3B and the guide cylinder member 6B, and the cylinder body 2B and the piston member 3B move in a parallel state. Hold and move relatively. The stroke limiting mechanism 7B, which limits the maximum stroke of the piston member 3B so that the cylinder body 2B forces and the piston member 3B does not come off, is composed of a flange 2d and an annular locking portion 6a. ing. FIG. 4 shows a state where the piston member 3B has advanced to the maximum. The structure of the guide tube member 6B is the same as that of the guide tube member 6 except for the annular locking portion 6a. The function and effect of the gas spring 1B are basically the same as those of the gas spring 1, but the structure of the piston member 3B is simplified, and the contact between the cylinder body 2B and the guide cylinder member 6B is achieved. Since the area is small, the frictional resistance is small. The piston member 3B of the gas spring 1B may be the same piston member as the piston member 3A of the gas spring 1A shown in FIG. 3] Modification 3 (See Figures 5 and 6)

The gas spring 1C shown in Fig. 5 is for the guide of the gas spring 1 in Figs. 1 and 2. This is almost the same as that in which the tubular member 6 is omitted. A base member 5 C, which is orthogonal to the biston member 3, is fixed to the lower end of the piston member 3 with bolts 22, and the base member 5 C is formed of a rectangular plate material. A mounting bolt hole 27 is formed. When assembling the gas spring 1C to a mold or the like, the base member 5C is brought into contact with the base surface, and the bolt 28 inserted through the pair of mounting bolt holes 27 is attached to the base surface. It shall be fixed by screwing into the bolt hole. The shape of the base member 5C is not limited to a rectangle, but may be various shapes such as a square, a circle, and an ellipse. The number of mounting bolt holes 27 is not limited to two, but may be one or three. That's all. In this gas spring 1C, the lubricating action and the gas sealing action of the sliding portion between the cylinder body 2 and the piston member 3 are the same as those of the gas spring 1. However, in the gas spring 1C, since the guide cylinder member 6 is omitted, the guide action by the guide cylinder member 6 cannot be obtained. Suitable for small gas springs. As the piston member 3 of the gas spring 1C, a piston member similar to the piston member 3A of the gas spring 1A of FIG. 3 may be applied.

4] Modification 4 (See Fig. 7)

The gas spring 1D shown in FIG. 7 is a gas spring used in a state where it is attached to the lower mold 40, and the gas spring 1D has a configuration other than the base member 5 and the guide cylinder member 6. Therefore, the description is omitted.

A guide cylinder member 6D forming an annular guide hole 23 for slidably mounting the cylinder body 2 outside the piston member 3 is fixed to the lower mold 40. The cylinder member 6D guides the piston member 3 and the cylinder body 2 so as to maintain a parallel state. A vertical cylindrical hole 41 for mounting the guide cylinder 6D is formed in the mold 40, and the guide cylinder 6D is fitted into the cylindrical hole 41 in an inner fitting manner. Is fixed. A horizontal base surface 42 is formed at the bottom of the cylindrical hole 41, and the output end of the piston member 3 is in contact with the base surface 42. An annular dust seal 24 is attached to the annular groove at the inner surface at the upper end of the guide cylinder 6D, and a breathing hole 25 is formed at the lower end of the guide cylinder 6D. This breathing hole 25 is a mold 40 It is connected to a passage 43 that leads to the atmosphere inside. Fig. 7 shows a state in which the piston member 3 has advanced to the maximum. In this state as well, the lower end of the cylinder body 2 is fitted inside the upper end of the guide cylinder member 6D, and the screw is inserted into the cylinder body 2. When the ton member 3 retreats, the cylinder body 2 is guided while entering the guide hole 23, so that the cylinder body 2 and the piston member 3 relatively move while maintaining a parallel state. As described above, the gas spring 1D basically has the same functions and effects as those of the gas spring 1. However, the base plate of the gas spring 1A in FIG. 3 and the gas spring 1B in FIG. 4 may be omitted, and the configuration may be the same as that of the gas spring 1D. 5] Modification 5 (see Fig. 8)

This gas spring 1E is configured such that the structure of the cylinder body 2E and the structure of the base member 5E are changed, and the compressed gas is charged into the gas working chamber 4 from the base member 5E. It is. The cylinder body 2E includes a cylindrical body 2a, an upper wall 2e integral with the cylindrical body 2a, and a lower end wall 2c. The gas spring 1E is connected to the gas supply pipe 14a for compressed gas supply, so that the base member 5E with a large thickness is applied, and the rod part 3a of the piston member 3E is used. Has a gas passage 13a communicating with the concave hole 20 and a gas passage 13b communicating with the gas passage 13a is formed in the base member 5E, and extends from the compressed gas supply source. The gas supply pipe 14a is connected to the gas passage 13b, and the boundary between the gas passages 13a and 13b is provided with a 0 ring 13c for sealing. E basically has the same function and effect as the gas spring 1, and has the gas passages 13a and 13b formed between the base member 5E and the piston member 3E on the stationary side. With the gas supply pipe 14a connected, replenish the compressed gas to the gas working chamber as necessary, and use the gas spring 1E Can be used.

In addition, in the gas springs 1A to 1C, similarly to the gas spring 1E, a gas passage is formed in the piston member and the base member, and the gas spring is connected to the gas supply pipe in the gas passage of the base member. May be configured to be used.

In the gas spring 1D, a gas passage for filling the compressed gas is formed in the piston member 3 and the gas spring is connected to the gas passage with a gas supply pipe connected thereto. It may be configured to use 1D.

6] Another embodiment (see FIGS. 9 and 10)

The gas spring 1F shown in FIG. 9 converts the gas spring 1A shown in FIG. 3 into a normal posture, which is not an inverted posture, and the oil 4a and the base member 5 and the guide cylinder member 6 in the cylinder body 2. Are omitted, and the oil supply mechanism 50 is incorporated inside the piston member. Therefore, the same components as those of the gas spring 1A are denoted by the same reference numerals, and description thereof will be omitted.

The gas working chamber 4 defined by the cylinder body 2 and the piston member 3F is filled with the same compressed gas as described above. A packing 30a and a backup packing 30b are mounted in an annular packing groove on an outer peripheral portion of the piston portion 3b of the piston member 3, and an oil is filled in an annular oil groove on an outer peripheral portion of the piston portion 3b. An impregnable annular fiber material 31 is installed.

An oil storage chamber 51 having a circular cross section is formed in the center of the piston member 3F from the upper end of the rod part 3a of the piston member 3F to the middle part of the piston part 3b. The chamber 51 is filled with oil 52 for lubricating the sliding portion 21F between the cylinder body 2 and the piston member 3F, and the oil storage chamber 51 is provided at the upper end of the rod portion 3a. A plug 53 for closing the upper end is detachably screwed. In addition, a small clearance for breathing (a small clearance through which the oil 52 cannot flow) is formed between the outer peripheral surface of the plug 53 and the rod portion 3a.

A fibrous material 54 that can be impregnated with oil is attached to the bottom of the oil storage chamber 51, and one or more thin oil supply holes that communicate with the oil groove from the bottom of the oil storage chamber 51 can be impregnated with oil. Fiber material 5 5 is installed. Further, a cylindrical body 56 having a substantially cylindrical fiber material that can be impregnated with oil is mounted on an outer peripheral portion of the oil storage chamber 51. As shown in FIG. 10, this cylindrical body 56 is fixedly attached to one side of a thin stainless steel plate 56a with a felt membrane 56b as a fiber material that can be impregnated with oil. It is attached by bending it into a substantially cylindrical shape so that it will be inside

. The fibrous materials 54, 55 and the felt film 56b correspond to a replenishing fibrous material. If this gas spring 1F is used in the normal position shown in Fig. 9, While there is enough oil 52 in the roulette chamber 51, the oil 52 is supplied to the annular fiber material 31 via the fiber materials 54, 55, and the piston portion 3 from the annular fiber material 31. A small amount is supplied to the sliding portion 21F between b and the cylinder body 2 to lubricate the sliding portion 21F. When the oil 52 in the oil storage chamber 51 decreases and the gas phase in the oil storage chamber 51 becomes negative pressure, the oil 52 in the oil storage chamber 51 becomes a filter membrane 5 6 b. And the fibrous material 54, 55 to the annular fibrous material 31. As a result, the negative pressure of the gas phase in the oil storage chamber 51 increases. When the negative pressure of the gas phase becomes larger than the ventilation resistance of the minute gap on the outer peripheral surface side of the plug 53, air flows into the oil storage chamber 51 from the minute gap. By repeating this, almost all of the oil 52 in the oil storage chamber 51 can be supplied to the annular fiber material 31 for lubrication. However, when the oil 52 in the oil storage chamber 51 is significantly reduced, the plug 53 can be removed to replenish the oil 52 into the oil storage chamber 51. If there is no filter membrane 56b, it is necessary to form a breathing passage for breathing so that the gas phase in the oil storage chamber 51 does not become negative pressure. The gas spring 1F cannot be used in an upside down position due to easy leakage and oil leakage. However, this gas spring 1F can be used in an inverted posture (upside down in FIG. 9) if necessary. Even when the gas spring 1F is used in the inverted posture, regardless of the amount of the oil 52 in the oil storage chamber 51, the oil 52 in the oil storage chamber 51 retains the filter membrane 5 6b. Thus, the sliding portion 21F between the piston portion 3b and the cylinder body 2 can be reliably lubricated. Here, when the gas spring 1F is used in an inverted posture, it is desirable to form a thin air passage 57 as shown by a virtual line in order to allow air to flow into the oil storage chamber 51 when the oil is reduced. . The air passage 57 communicates with a minute gap on the outer peripheral side of the plug 53, extends inside the mouth 3 a, and communicates with the bottom of the oil storage chamber 51.

Incidentally, the cylindrical body 56 is merely an example, and may be constituted only by a member made of a fibrous material that can be impregnated with oil, and is not necessarily required to be cylindrical or substantially cylindrical. The oil storage chamber 51 may have a length extending from the bottom to the top. However, any configuration may be used as long as the oil storage 51 maintains the state from the bottom to the top of the gas spring 1F even if impact or vibration is applied during use.

Claims

The scope of the claims

1. A cylinder body that is arranged upside down in a vertical position,

A piston member movably attached to the cylinder body through a rod hole formed in a lower end wall of the cylinder body;

A compressed gas filled in a gas working chamber defined by the cylinder body and the piston member to urge the piston member toward the advance side;

Oil contained in a gas working chamber for lubricating a sliding portion between the cylinder body and the piston member,

A base member fixed to an output end on the lower end side of the biston member,

A guide cylinder member fixed or integral with the base member and forming an annular guide hole for guiding the cylinder body outside the piston member;

A gas spring, comprising: a stroke limiting mechanism that limits a maximum stroke of the piston member so that the piston member does not separate from the cylinder body.

2. The gas spring according to claim 1, wherein a gas passage for filling compressed gas is formed in the base member and the biston member.

3. The piston member includes a piston portion and a rod portion having a smaller diameter than the piston portion, and the stroke limiting mechanism includes a piston portion and a lower end wall portion of the cylinder body. The gas spring according to claim 1 or 2, wherein

4. The gas spring according to claim 1, wherein the piston member is formed in a mouth shape, and the mouth portion functions as a piston portion.

5. The guide hole is formed as a cylindrical hole, and the stroke limiting mechanism is constituted by a locking portion formed at an upper end of the piston member and a lower end wall of the cylinder body. The gas spring according to claim 4, wherein:

6. The stroke limiting mechanism includes an annular flange formed at the lower end of the cylinder main body, and an upper end of the guide cylinder member slidable on the cylinder main body so as to face the flange. 5. The gas spring according to claim 4, wherein the gas spring comprises an annular locking portion formed so as to be fitted to the outside.

7. The cylinder body, which is arranged upside down in a vertical position,

Oil contained in a gas working chamber for lubricating a sliding portion between the cylinder body and the biston member;

A base member fixed to the lower end output end of the biston member,

A plurality of mounting bolt holes formed in the base member,

A stroke limiting mechanism for limiting the maximum stroke of the piston member so that the piston member does not separate from the cylinder body;

A gas spring comprising:

8. The gas spring according to claim 7, wherein a gas passage for filling compressed gas is formed in the base member and the piston member.

9. For gas springs that are used while attached to the mold,

A cylinder body disposed in an upright position in a vertical position,

A compressed gas filled in a gas working chamber defined by the cylinder body and the biston member to urge the piston member toward the advance side;

A guide cylinder member fixed to the mold, the guide cylinder member forming an annular guide hole for guiding the cylinder body outside the piston member;

A stroke limiting mechanism for limiting the maximum stroke of the piston member so that the piston member does not separate from the cylinder body; A gas spring comprising:

10. The gas spring according to claim 9, wherein a gas passage for filling the compressed gas is formed in the biston member.

1 1. The cylinder body and

A piston member movably attached to the cylinder body through a rod hole formed in an upper end wall or a lower end wall of the cylinder body, the piston and a smaller-diameter mouthpiece. A biston member having a portion,

A compressed gas filled in a gas working chamber defined by the cylinder body and the biston portion to urge the biston member toward the advance side;

An oil storage chamber formed in the piston member and storing oil supplied to a sliding portion between the cylinder body and the piston portion;

A gas spring comprising:

12. An annular fiber material capable of impregnating oil is mounted in an annular groove in an outer peripheral portion of the piston portion, and a supplementary fiber material capable of impregnating oil is provided in the oil storage chamber from the top to the bottom thereof. 12. The gas spring according to claim 11, wherein the oil in the oil storage chamber is supplied to the annular fiber material via the supply fiber material.