JPH1113711A - Cylinder gasket for rodless cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder gasket to reliably prevent leakage of fluid from the two ends of a cylinder tubes and to provide stable sealing property. SOLUTION: A gasket groove is formed in an end cap 11 fitted in each of openings in the two ends of a cylinder hole. A cylinder gasket 15 is fitted in a gasket groove. A protrusion 44 and a thick section part 45 are formed on the inner seal band side of the cylinder gasket 15 and compared with other part, a line shape is increased in size. This constitution performs further reliable stable sealing in a state to make forced contact of the inner surface of the cylinder hole of the cylinder gasket 15 with an inside seal band compared with a conventional type and prevents the occurrence of leakage of fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a state in which a gasket groove provided in a fitting shaft portion of an end member is fitted, and both longitudinal openings of a cylinder hole provided in a cylinder tube are closed by the end member. The present invention relates to a cylinder gasket of a rodless cylinder which presses against an inner surface of a cylinder hole and an inner seal band to seal both ends of the opening.

[0002]

2. Description of the Related Art Conventionally, in a rodless cylinder, a slit extending in a longitudinal direction provided in a cylinder tube is closed by a seal band, and openings at both longitudinal ends of a cylinder hole are closed by end members. A cylinder gasket (seal member) is fitted into a gasket groove (mounting groove) provided in a fitting shaft portion (fitting portion) of the end member that fits with the cylinder hole,
The cylinder gasket is pressed against the inner seal band and the inner surface of the cylinder hole to seal the openings at both ends. The pressurized fluid easily leaks at the gathering portion between both ends of the inner seal band and the inner surface of the cylinder hole, and the cylinder gasket is strongly pressed against this gathering portion. For example, a cylinder gasket for such a rodless cylinder is disclosed in
One disclosed in Japanese Patent Publication No. 269514/269 is known. On the bottom surface opposite to the inner seal band of the mounting groove for mounting the seal member formed at the fitting portion of the end cover fitted into the opening at both ends of the cylinder tube, there is a pressing projection projecting toward the inner seal band. Is formed. A seal member is fitted into the mounting groove, and a portion of the seal member facing the inner seal band is pressed by a pressing protrusion at a higher pressure than a portion pressed against the inner surface of another cylinder hole, thereby preventing leakage of compressed air. ing. Also, since the mounting groove is formed deeper than the conventional one and only the portion corresponding to the pressing protrusion has the same depth as the conventional one, the amount of protrusion of the seal member is small except for the pressing protrusion, and the end cover is attached. At this time, only the portion corresponding to the pressing protruding portion needs to be strongly compressed, and there is an advantage that the fitting is easy and breakage of the seal member can be prevented.

[0003]

In the above-mentioned conventional cylinder gasket, the gasket groove is formed deeply, so that the end member fitted with the cylinder gasket can be easily fitted to the cylinder tube, which is preferable. However, since the pressing protrusion is formed on the bottom surface on the inner seal band side of the gasket groove, and the cylinder gasket is fitted into the pressing protrusion, the inner peripheral surface of the cylinder gasket is elastically deformed by the gasket, especially on both sides of the pressing protrusion. The pressurized fluid may leak at both sides of the pressing protrusion and the fitting portion between the inner peripheral surface of the cylinder gasket. In addition, when the end member is molded from a material such as resin using a mold, the shape of the end member is complicated, including the pressing protruding portion, so that the shape of the mold for forming the end member is also complicated, resulting in cost reduction in mold processing. There was a problem. Also, it is well known that when a cylinder gasket having a large wire diameter is used, compression set is small and stable sealing performance can be obtained. Even if it is the same, the part corresponding to the inner seal band of the cylinder gasket is pressed against the inner seal band side more strongly than the part pressed against the inner surface of the other cylinder hole by the press projection, so that the inner seal is sealed. In the part corresponding to the band, there was a problem that the compression set became large and stable sealing properties could not be obtained. The problem to be solved by the present invention is that when closing both ends of a cylinder tube of a rodless cylinder with an end member, it is possible to reliably prevent leakage of fluid and to obtain a stable sealing property.
Moreover, it is an object of the present invention to provide a cylinder gasket that can be manufactured at low cost.

[0004]

In order to solve the above problems, a slit and a cylinder hole are provided along the longitudinal direction of the cylinder tube, the inside of the opening of the slit is closed with an inner seal band, and both ends of the longitudinal direction of the cylinder tube are terminated. Used in a rodless cylinder closed by a member, the cylinder is fitted in a gasket groove provided in a fitting shaft portion of the end member, and the fitting shaft portion of the end member is fitted in both longitudinal openings of the cylinder hole. In the cylinder gasket of the rodless cylinder which presses the inner surface of the hole and the inner seal band and seals both ends of the cylinder tube, the wire diameter on the inner seal band side is increased (claim 1).

In the cylinder gasket, when the inner seal band is pressed against both inner surfaces in the width direction of the slit, the shape on the inner seal band side corresponds to the state (claim 2). More specifically, a projection is provided which enters into a depression formed between both end portions of the inner seal band and both inner surfaces in the width direction of the slit, and a wire diameter between the projections is smaller than that of the projection portion, and is pressed against the inner surface of the cylinder hole. A thick portion is provided on the inner surface of the inner seal band, which is larger than the wire diameter of the portion to be pressed, on the cylinder hole side (claim 3).

Further, when the shape of the cylinder hole is formed in an elliptical shape, the cylinder hole has an oval shape corresponding to the shape of the cylinder hole.

Preferably, a concave portion is provided on a side surface of the cylinder gasket portion corresponding to the inner seal band.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. The cylinder tube (body) 2 of the rodless cylinder 1 is formed by extruding or drawing a non-magnetic material (for example, aluminum alloy) and has a non-circular (oblong) cylinder hole 3.
A slit 4 is formed over the entire length in the longitudinal direction. In addition to the cylinder hole 3 and the slit 4 as shown in FIGS. 2 and 3, the cylinder tube 2 has a mounting groove 5 for mounting an end member and a sensor parallel to the cylinder hole 3 on the left and right outer wall surfaces in the width direction. An attachment groove 6 is formed.

The cylinder hole 3 is an elliptical non-circular cylinder hole, and the slit-side inner surfaces 7 and 7 which are plane surfaces and the slit-side inner surface 8 which faces the slit 4 are arc-shaped (semicircle) on both sides of the slit 4. The slit-side inner surfaces 7, 7 are continuous with the slit-side inner surfaces 7, 7 on both sides in the width direction of the slit 4. It is formed.

Both longitudinal end portions of the cylinder tube 2 are closed by left and right end caps 11, 11 shown as end members, and a cylinder chamber 1 is provided between the left and right end caps 11, 11.
3 is formed. Left and right end caps 11, 11
Is the same except that the left and right shapes are symmetrical. Therefore, the following description will be made based on the drawings showing the left end cap 11. In FIG. 1, the end cap 11 and the cylinder tube 2 are fitted into the cylinder hole 3 of the end cap 11 in which the cylinder gasket 15 is fitted.
In a state fitted in the openings at both ends, it is attached to the end of the attachment groove 5 for attaching the end member by a tapping screw (not shown).

The cylinder chamber 13 is divided into front and rear cylinder chambers 13A and 13B by a piston 18 having piston ends 18b at both ends of a piston body 18a. A piston yoke 19 penetrating through the slit 4 is formed integrally with the piston body 18a. The piston yoke 19 extends right and left outside the cylinder tube 2 to form a piston mount 20. In the piston mount 20, a band passing space 21 through which the outer seal band 26 passes is covered with a cover member 22 made of a resin material. A moving body 23 is constituted by the piston 18, the piston yoke 19, and the piston mount 20. A scraper 24 is attached to the entire periphery of the lower end of the piston mount 20 to prevent dust from entering from a gap between the upper surface of the cylinder tube 2 (the outer surface on the opening side of the slit 4) and the lower surface of the piston mount 20. Preventing.

The inside and outside of the slit 4 are closed by inner and outer seal bands 25 and 26. The inner and outer seal bands 25 and 26 pass above and below the piston yoke 19, and both ends thereof are connected to the left and right end caps 11. The inner and outer seal bands 25 and 26 are thin and elastic flexible bands, and are made of a magnetic material such as a steel band. As is well known, the inner and outer seal bands 25 and 26 have a width larger than the width of the slit 4. Of these, the outer seal band 25,
Reference numeral 26 denotes a slit 4 on the outer surface of the cylinder tube 2.
Except for the portion that is attracted by the magnets 31 arranged along the length on both sides and passes through the piston yoke 19,
The inner seal band 25 closes the slit 4 from the inside by the magnetic attraction force and the fluid pressure applied to the cylinder chamber 13, and the outer seal band 26 closes the slit 4 from the outside by the magnetic attraction force.

The inner seal band 25 has an inner surface (cylinder hole side surface) 25a facing the cylinder hole 3 as shown in FIG.
Inclined surface 3 whose both ends in the width direction are inclined toward the edge portion
3, the widthwise ends of the outer surface 25b opposite to this are pressed against the widthwise inner surfaces 10, 10 of the slit 4, and the both ends of the inner seal band 25 and the widthwise inner surfaces 10, 10 are pressed. Thus, a depression 34 is formed.

As shown in FIGS. 1 and 5, the end cap 11 has band insertion holes 27 and 28 into which the inner and outer seal bands 25 and 26 are respectively fitted. Further, a pin hole 29 is provided extending vertically and penetrating the band insertion holes 27 and 28. This band insertion hole 2
Both ends of the inner and outer seal bands 25 and 26 in the longitudinal direction of the inner and outer seal bands 25 and 26 are fitted into the mounting holes 7 and 28, and the mounting holes 3 (not shown) provided at both ends are aligned with the pin holes 29.
0, the inner and outer seal bands 25, 26 are connected to the end cap 11. Also, end cap 1
A cap cover 32 is attached to 1 to prevent the attachment pin 30 from coming off from above.

The end cap 11 has a fitting shaft portion 14 that is fitted into the cylinder hole 3 and protrudes therefrom. The fitting shaft 14 has an oval shape corresponding to the shape of the cylinder hole 3. The large diameter portion 35 of the fitting shaft portion 14 fits into the cylinder hole 3. The distal end portion of the fitting shaft portion 14 is a small diameter portion 36, and a fitting hole 37 is formed in the small diameter portion 36. The fitting portion 39 of the piston damper 38 is fitted into the fitting hole 37, and the piston damper 38 is integrally attached to the fitting shaft portion 14. The fitting shaft 14 and the piston damper 38 attached to the fitting shaft 14 form a gasket groove 40 into which the cylinder gasket 15 is fitted. The small diameter portion 36 of the fitting shaft portion 14 is a bottom wall 41 of the gasket groove 40.
The bottom wall 41 is a flat surface over the entire circumference (FIG. 6). The depth L of the gasket groove 40 is set to be deeper than the depth of a conventional gasket groove as disclosed in Japanese Patent Application Laid-Open No. 7-269514. As shown in FIG. 6, the depth L of the gasket groove 40 is
When the end member 11 is fitted to the cylinder tube 2 by fitting the cylinder gasket 15 to the cylinder tube 2, the portion of the cylinder gasket 15 that is not the large diameter portion (the same wire diameter as the conventional one) is The value is set to a value sufficient to prevent leakage of the pressurized fluid from between. In a state where the cylinder gasket 15 is fitted into the gasket groove 40, as shown in FIGS.
, The cylinder gasket 15 protrudes. The protrusion amount of the cylinder gasket 15 at the portion in pressure contact with the inner surface of the cylinder hole 3 is smaller than the conventional gasket groove since the depth L of the gasket groove 40 is set deeper than the conventional gasket groove. . Also, piston damper 3
At the center of 8, a supply / discharge hole 43 communicating with the supply / discharge hole 42 of the end cap 11 is provided.

The cylinder gasket 15 fitted in the gasket groove 40 is, as shown in FIG.
It is formed in an oval ring shape according to the shape of. For this reason, when the cylinder gasket 15 is fitted into the gasket groove 40, the degree of deformation is smaller than when a commercially available standard round gasket is fitted into the elliptical gasket groove, and the cylinder gasket 15 is less likely to bend, and the fitting is less likely. The shaft portion 14 is easily fitted into the cylinder hole 3. The inner diameter of the cylinder gasket 15 is set smaller than the outer diameter of the bottom wall 41 of the gasket groove 40. On the inner seal band 25 side of the cylinder gasket 15, it has a shape corresponding to the depression 34 formed between both ends in the width direction of the inner seal band 25 and the inner surfaces 10 on both sides in the width direction. 44 are provided. The projections 44, 44
The thick portion 45 is in contact with the inner side surface 25a of the inner seal band 25 in pressure. The thickness of the thick portion 45 is smaller (thinner) in the compression direction than in the protrusion 44, and is larger than the wire diameter of the other portion which is pressed against the inner surface of the cylinder hole 3 (the same wire diameter as the conventional one) ( Thick). The wire diameter of the projection 44 and the thick portion 45 is at least set in the gasket groove 40 which is set deeper than the conventional one, and when the inner seal band 25
And a protruding amount sufficient to prevent leakage of the pressurized fluid from between the end cap 11 and the gasket groove of the conventional depth.
(Same as when a gasket with a conventional wire diameter is fitted). That is, at least the gasket groove 40 is made thicker by the depth. The projection 44 and the thick portion 4
5, the wire diameter of the portion corresponding to the inner seal band 25 and the recess 34 becomes thicker, and the gathered portion of the inner seal band 25, the recess 34, and the cylinder gasket 15 where fluid easily leaks is more stably sealed than in the past. .

The cylinder gasket 1 is inserted into the gasket groove 40.
5 is fitted into the cylinder tube 2
The cylinder gasket 15 is fitted into the opening at both ends and presses against the inner surface of the cylinder hole 3 and the inner seal band 25 from the inside to close both ends of the cylinder tube 2. The projection 44 of the cylinder gasket 15 enters the recess 34, and the thick portion 45 presses against the inner surface 25 a of the inner seal band 25,
Other portions are pressed against the inner surface of the cylinder hole 3. The portion of the cylinder gasket 15 where the protrusion 44 is provided has the largest wire diameter and therefore has a high compression stiffness, and the recess 34 where the pressurized fluid leaks most easily is pressed against by a strong restoring elasticity (pressing force) to provide high sealing performance. can get. Further, since the portion corresponding to the inner seal band 25 is formed in the thick portion 45 which is thicker than the portion which is in pressure contact with the inner surface of the other cylinder hole 3, the inner seal band 25 where the pressurized fluid easily leaks is formed. The compression stiffness is high even at the pressure contact portion between the cylinder portion and the cylinder gasket 15, and the thick portion 45 is pressed by the large restoring elasticity, so that the sealing property is good. Although a stronger restoring elasticity acts on these projections 44 and thicker portions 45 as compared with other portions, it is strongly pressed against the inner seal band side using a cylinder gasket having a constant wire diameter as in the prior art. Since the wire diameter on the side of the inner seal band is larger than that to be formed, the compression set becomes small, and a stable and high sealing property can be obtained. Further, since the depth L of the gasket groove 40 is set to be larger than in the past,
The projections 44 and the thick portions 45 provided on the cylinder gasket 15 protrude at least to the same extent as in the prior art when fitted into the gasket groove 40, and the other portions have a small amount of protrusion, so the cylinder hole of the fitting shaft portion 14 is small. When fitting the end cap 11 into the cylinder tube 2, it is sufficient to compress only the protrusion 44 and the thick portion 45 with a strong force.

The end cap 11 is made of a synthetic resin and is molded by a metal mold. This metal mold has a complicated shape and is expensive. For this reason, the provision of the pressing protruding portion is more complicated and expensive. On the other hand, in the present application, the cylinder gasket 15
Since the projections 44 and the thick portions 45 are provided on the base and formed into a shape that matches the gasket groove 40, a mold for the cylinder gasket 15 is required. Since the gasket mold has a simple gasket shape, even if the mold is provided with the projections 44 and the thick portions 45, the shape of the mold is smaller than that of the conventional mold of the end cap 11 which is provided with a pressing protrusion. Is less complicated and less expensive.

Reference numeral 46 denotes an external damper, which is attached to the end cap 11 on the side facing the piston mount 20, abuts against the piston mount 20 at the stroke end of the piston mount 20, and moves the movable body 23 together with the piston damper 38. Absorb energy.

Next, a second embodiment will be described with reference to FIGS. As in the above-described embodiment, it is formed in an annular elliptical shape, and a projection 44 is provided at a portion corresponding to the depression 34.
Are formed in the thick portion 45. A concave portion 47 is formed on a side surface of the thick portion 45. This recess 4
7, even if the wire diameter of the thick portion 45 is made larger in the compression direction (vertical direction) of the cylinder gasket 15 than in the first embodiment, the thickness of the thick portion 45 is adjusted by adjusting the size of the concave portion 47. Since the pressing force by the restoration elasticity can be adjusted,
Even if the wire diameter is made larger, the pressing force of the thick portion 45 does not become too strong, and the fitting shaft portion 1 fitted with the cylinder gasket 15 is used.
There is no need to strongly compress the 4 when it is fitted into the cylinder hole 3, and it is easy to fit. Further, since the diameter of the protrusion 44 and the thick portion 45 in the compression direction can be increased by providing the concave portion 47 as compared with the first embodiment, the compression set can be further reduced, and more stable sealing performance can be obtained. can get.

Further, unlike the third embodiment shown in FIG. 13, no projection is provided on the inner seal band 25 side of the cylinder gasket 15 and the thick portion 4
5, a concave portion 47 is provided on the side surface of the thick portion 45 corresponding to the inner seal band 25. Even when the projection is not provided, the concave portion 47 is not provided up to the side surface of both sides of the thick portion 45 (the portion corresponding to the recess 34), so that both sides of the thick portion 45 are pressed against the recess 34 most strongly, The thick portion 45 corresponding to the inner seal band 25 is deformed into a shape corresponding to the inner seal band 25 by the recess 47 and pressed against the inner seal band 25.

In the above embodiment, the cylinder gasket has an elliptical shape according to the shape of the cylinder hole.
It is also possible to make it circular. In this case, by setting the size of the inner circumference smaller than the expected size, it is possible to reduce the deflection generated when the cylinder gasket is fitted into the gasket groove. It is easier to insert the insertion shaft portion into the cylinder hole. Of course, the present invention can be applied to a case where the cylinder hole is circular.

[0023]

As described above, in the present invention, since the wire diameter on the inner seal band side is increased, even if the bottom wall of the gasket groove into which the cylinder gasket is fitted is made a smooth (flat) surface, the inner seal band can be used. Can be pressed against the inner seal band with a large pressing force, and the sealing performance at the pressed area can be enhanced. Is obtained. In addition, since the bottom wall of the gasket groove into which the cylinder gasket is fitted can be made smooth, the inner peripheral surface of the gasket is securely adhered to the bottom wall when the cylinder gasket is fitted into the gasket groove. The sealing function between the inner peripheral surface of the gasket and the bottom wall can be enhanced as compared with the case where the pressing projection is provided on the bottom wall.

Further, by increasing the depth of the gasket groove so that the thicker part of the gasket protrudes from the gasket groove to the same extent as the conventional one, the other parts of the gasket other than the thicker part of the gasket are removed. The protrusion amount can be reduced, and the end member can be easily fitted into the cylinder hole via the gasket.

If the cylinder gasket has an oval shape corresponding to the cylinder hole, that is, a shape corresponding to the cylinder groove of the fitting shaft portion, the cylinder gasket bends when the cylinder gasket is fitted into the cylinder hole. Therefore, the end member can be easily attached to the cylinder tube with the cylinder gasket attached to the end member.

Also, by providing a concave portion on the side surface of the cylinder gasket portion corresponding to the inner seal band, the cylinder gasket can be compressed with the same force even if the wire diameter of the cylinder gasket is made larger than that without the concave portion. As a result, the fitting shaft portion can be easily fitted into the cylinder hole, and the linearity can be made wider than that without the concave portion, so that the compression set is further reduced and stable sealing performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a rodless cylinder embodying the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a diagram showing a cross-sectional shape of a cylinder tube.

FIG. 4 is an enlarged view of a part IV in FIG. 3;

FIG. 5 is a sectional view showing a state where a cylinder gasket is attached to an end cap.

6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a front view of a cylinder gasket.

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a sectional view taken along line IX-IX of FIG. 7;

FIG. 10 is a sectional view taken along line XX of FIG. 7;

FIG. 11 is a second embodiment.

12 is a sectional view taken along line XII-XII in FIG.

FIG. 13 shows a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rodless cylinder 2 Cylinder tube 3 Cylinder hole 4 Slit 10 Inner surface of both sides in the width direction 11 End member 14 Fitting shaft part 15 Cylinder gasket 25 Inner seal band 34 Depression 40 Gasket groove 44 Projection 45 Thick part 47 Depression

Claims (5)

[Claims] Claims: 1. A rodless cylinder comprising a slit and a cylinder hole provided along a longitudinal direction of a cylinder tube, an inside of the slit is closed with an inner seal band, and both longitudinal ends of the cylinder tube are closed with end members. It is fitted in a gasket groove provided in the fitting shaft portion of the end member, and presses against the inner surface of the cylinder hole and the inner seal band in a state where the fitting shaft portion of the end member is fitted in the opening at both ends in the longitudinal direction of the cylinder hole, What is claimed is: 1. A cylinder gasket for a rodless cylinder, wherein a diameter of an inner seal band is increased in a cylinder gasket of a rodless cylinder for sealing both ends of a cylinder tube. 2. The rodless cylinder according to claim 1, wherein the shape of the inner seal band is a shape corresponding to the state in which the inner seal band is pressed against both inner surfaces in the width direction of the slit. Cylinder gasket. 3. A projection which enters a recess formed between both end portions of the inner seal band and both inner surfaces in the width direction of the slit, and has a wire diameter smaller than the projection portion between the projections, and presses against the inner surface of the cylinder hole. 3. The cylinder gasket for a rodless cylinder according to claim 2, wherein a thick wall portion is provided to be in pressure contact with the inner side surface of the inner seal band on the cylinder hole side which is larger than the wire diameter of the portion to be pressed. 4. The rod according to claim 1, wherein when the shape of the cylinder hole is formed in an oval shape, the rod shape is an oval shape corresponding to the shape of the cylinder hole. Cylinder gasket for less cylinder. 5. The cylinder gasket for a rodless cylinder according to claim 1, wherein a concave portion is provided on a side surface of the cylinder gasket portion corresponding to the inner seal band.