JP5839995B2 - Fluid pressure cylinder boot, fluid pressure cylinder, and rod protection structure - Google Patents

Description

  The present invention relates to a boot, a fluid pressure cylinder, and a rod protection structure capable of protecting a rod of a fluid pressure cylinder from dust and the like.

  Conventionally, for example, as shown in FIGS. 6 to 8, an all-hydraulic rear axle is supported on a vehicle body frame (not shown) so as to be swingable by a center pin 3 protruding forward and rearward, and a rear axle beam. 2 has a hydraulic cylinder 4 at the center, and left and right turning wheels 7, rims 8 and hubs 9 have left and right knuckles 10 and a king pin 11 which are rotatable substantially perpendicular to the ground on both ends of the rear axle beam 2. It is installed as a shaft. The left and right knuckle 10 is configured by connecting the arm 12 of the knuckle 10 and the rod end of the hydraulic cylinder 4 with a yoke 13.

  However, there are cases in which dirt such as mud and wet waste paper is scattered and volumetric on the road surface in the environment where the vehicle is used. In such a usage environment, the dust on the road surface is often scooped up by the rotating wheel 7 that rotates while the vehicle is running and adheres to the rod 4c of the hydraulic cylinder 4. In particular, wet waste paper or the like adheres firmly to the rod 4c when dried after drying.

  A large amount of such dust adheres to the rod 4c, and thus passes or damages the dust seal of the cylinder cap 4b, damages the packing inside the cylinder, and finally causes a problem of oil leakage of the hydraulic cylinder 4.

  Therefore, as shown in FIGS. 9 and 10, there is a structure for preventing dust by installing a cover 6X in a portion where the hydraulic cylinder 4 is mounted between the upper flange plate 2a and the lower flange plate 2b of the rear axle beam 2. Proposed.

  The cover 6X shown in FIGS. 9 and 10 can be manufactured at low cost, but the sliding of the arm 12 of the knuckle 10 and the yoke according to the expansion and contraction of the hydraulic cylinder 4 during steering of the diverting wheel 7 (see FIG. 8). Since 13 moves, there are many portions that do not cover the rod 4c, that is, there are many gaps in which dust enters, which is not sufficient as dust removal. As an improvement, for example, a cylinder cover for an industrial vehicle disclosed in Patent Document 1 is also known. However, this also does not sufficiently cover the rod of the hydraulic cylinder, and is still unacceptable as dust removal. It was enough.

  As a structure for completely covering the rod of the hydraulic cylinder 4, a structure in which a dust boot 5X is covered on the rod is known as shown in FIGS. The material of the dust boot 5X is rubber, cloth, or general-purpose resin. This type of dust boot is mainly bellows-shaped, and the insertion port side is fixed to the cylinder cap of the hydraulic cylinder 4 with a band 15. Such a dust boot 5X protects the rod of the hydraulic cylinder 4 by interlocking the bellows portion of the dust boot 5X with the expansion and contraction of the hydraulic cylinder 4.

  In such a dust boot 5X, the outer shape of the bellows part of the dust boot 5X becomes large according to the expansion / contraction distance. That is, when the expansion / contraction distance of the hydraulic cylinder 4 is increased, the outer shape of the dust boot 5X is increased.

However, when the clearance CL (see FIG. 9) between the web plate 2c to which the hydraulic cylinder 4 of the rear axle beam 2 is fixed and the rod 4c of the hydraulic cylinder 4 is small, the outer shape of the bellows portion of the dust boot 5X is increased. I can't. In order to increase the expansion / contraction length of the dust boot 5X and reduce the outer shape of the bellows part, it is necessary to increase the number of bellows valleys. It is necessary to maintain a relationship of L _min > LB between the minimum length L _min when the rod is reduced (see FIG. 8) and the minimum length LB when the dust boot is reduced. Since the thickness of the material of the dust boot 5X is overlapped when the boot is reduced, the relationship of L _min > LB may not be maintained. In such a case, the dust boot 5X is crushed when the rod is reduced. End up. In the relationship of L _min <LB, a problem of early wear of the dust boot 5X occurs due to interference between the boot end 5e and the yoke 13.

JP 2006-160151 A

  The present invention is a case where the space around the rod is narrow depending on the installation environment of the fluid pressure cylinder, and even if the fluid pressure cylinder has a long stroke length, dust is not collected on the rod without causing damage to the components. It is a main object of the present invention to provide a fluid pressure cylinder boot, a fluid pressure cylinder, and a rod protection structure for the fluid pressure cylinder that can prevent adhesion.

  In order to achieve the above object, the fluid pressure cylinder boot according to the present invention has an expandable bellows shape that is extrapolated to the rod of the fluid pressure cylinder, and the length at the maximum extension is shorter than the stroke length of the rod, A cylinder cap of the fluid pressure cylinder having one end fixed to the rod end, a cover portion movably covered on the cylinder body, the other end of the cylindrical portion, and one end of the cover portion. And a collar portion capable of abutting on.

  Further, the fluid pressure cylinder according to the present invention is an accordion-like bellows shape that is externally attached to the attachment portion for attaching the fluid pressure cylinder to the mounting surface and the rod of the fluid pressure cylinder, and has a length at the maximum extension. A cylindrical portion that is shorter than the stroke length of the rod and has one end fixed to the rod end, a cover portion that is movably covered by the cylinder body, and the other end of the cylindrical portion and one end of the cover portion are connected, A flange that can contact the cylinder cap of the fluid pressure cylinder, and a notch that extends from the other end of the cover along the axial direction and is formed to avoid interference with the attachment. It is characterized by that.

  The fluid pressure cylinder according to the present invention has a bellows shape that can be extended and contracted by being inserted into the rod of the fluid pressure cylinder, has a maximum length that is shorter than the stroke length of the rod, and one end is fixed to the rod end. A cylindrical portion, a cover portion that is movably covered on the cylinder body, a flange portion that connects the other end of the cylindrical portion and one end of the cover portion, and that can contact the cylinder cap of the fluid pressure cylinder A boot mechanism comprising: a boot including: a stopper mechanism that restricts a movement amount of the cover portion within a predetermined range, and extends the cylindrical portion when the rod is extended, wherein the stopper mechanism is a cylinder body of the fluid pressure cylinder. And a locked portion provided in at least one of the cover portion and the flange portion.

  Furthermore, the rod protection structure for a fluid pressure cylinder according to the present invention has an accordion-like shape that is extrapolated to the rod of the fluid pressure cylinder and can be expanded and contracted. A cylindrical portion fixed to the end, a cover portion that is movably covered on the cylinder body, and the other end of the cylindrical portion and one end of the cover portion are connected to contact the cylinder cap of the fluid pressure cylinder. A boot that includes a flange, and a stopper mechanism that restricts the amount of movement of the cover within a predetermined range and extends the tubular portion when the rod is extended, the stopper mechanism including the fluid pressure It has the latching | locking part provided in the to-be-attached surface of the cylinder, and the to-be-latched part provided in at least one of the said cover part and a collar part, It is characterized by the above-mentioned.

  According to the present invention, the length of the bellows-like cylindrical portion is shorter than that of a conventional bellows-like boot that completely covers the rod, and the rod portion exposed by shortening the cylindrical portion is covered with the cover portion. Therefore, even with a fluid pressure cylinder with a long stroke length, it is possible to prevent dust from adhering to the rod while suppressing an increase in the outer diameter of the boot.

1 is a perspective view showing a fluid pressure cylinder boot together with a part of a fluid pressure cylinder, which is an embodiment of the present invention. It is a perspective view which shows the change aspect of embodiment of FIG. It is a perspective view which shows the other modification of embodiment of FIG. It is a perspective view which shows the further another modification of embodiment of FIG. It is a perspective view which shows the further another modification of embodiment of FIG. It is a partially omitted plan view showing an example in which a conventional fluid pressure cylinder is arranged on a rear axle. FIG. 7 is a front view of FIG. 6. It is a fragmentary sectional top view which shows the operating state of the steering wheel of the rear axle of FIG. It is a fragmentary sectional top view which shows the rod protection structure of the conventional fluid pressure cylinder. FIG. 10 is a front view of FIG. 9. It is a fragmentary sectional top view which shows the rod protection structure of the other conventional fluid pressure cylinder. It is a front view of FIG.

  An embodiment of a fluid pressure cylinder boot according to the present invention will be described below with reference to FIGS. Throughout the drawings including the conventional example, the same components are denoted by the same reference numerals, and redundant description may be omitted.

  In the fluid pressure cylinder boot 1, a cover portion 22 is connected to a cylindrical portion 21 having a bellows shape that can be expanded and contracted by a flange portion 23.

  The cylindrical portion 21 is extrapolated to the rod 4c of the hydraulic cylinder 4, and one end is fixed to the rod end 4e of the rod 4c. A rod end fitting 4 f is integrally provided on the rod end 4 e of the hydraulic cylinder 4. A rectangular through hole 21b through which the rod end fitting 4f is passed is formed in the one end surface 21a of the cylindrical portion 21. A female screw hole 4 d is formed in the rod end 4 e of the hydraulic cylinder 4. On one end surface 21a of the cylindrical portion 21, a through hole 21c for passing the female screw 24 is formed at a position matching the female screw hole 4d of the rod end 4e.

  The cylindrical portion 21 has a length at the time of maximum extension (when fully extended) shorter than a stroke length Lmax (see FIG. 8) of the rod 4c. Therefore, when the rod 4c is sufficiently extended, a rod portion that cannot be covered by the cylindrical portion 21 is generated, but the portion is covered by the cover portion 22.

  The cover part 22 is connected to the cylindrical part 21 via the flange part 23, and is movably covered on the cylinder body 4ab. The cylinder body 4ab is configured by attaching cylinder caps 4b to both ends of the cylinder tube 4a. The cover portion 22 has a shape that matches the outer diameter of the cylinder body 4ab, and may be a cylindrical shape, a semi-cylindrical shape, a rectangular cylindrical shape, a groove shape, a box shape, or the like.

  The flange portion 23 can contact the cylinder cap 4 b of the hydraulic cylinder 4. Therefore, when the rod 4c is contracted, the cylindrical portion 21 contracts in the axial direction by the flange portion 23 coming into contact with the cylinder cap 4b. The flange 23 is preferably reinforced with an iron plate or a resin plate to improve durability at the time of contact.

  In order to extend the cylindrical portion 21 in accordance with the extension of the rod 4c, a stopper mechanism that restricts the movement amount of the cover portion 22 within a predetermined range can be provided. That is, when the rod 4c is extended by a certain amount by the stopper mechanism, the movement of the cover portion 22 is stopped and the cylindrical portion 21 is extended.

  As shown in FIG. 2, the stopper mechanism can include a locking portion 25 provided on the cylinder body 4 ab and a locked portion 26 provided on the cover portion 22. In the example of FIG. 2, the locked portion 26 is a slit that is closed at both ends extending along the axial direction of the cover portion 22, and the locking portion 25 is provided in the cylinder body 4 ab of the hydraulic cylinder 4 and is locked. It is a locking projection that is inserted into the slit constituting the portion 26. In the example shown in the figure, the engaging protrusion constituting the locking portion 25 is formed by a male screw screwed into the cylinder cap 4b, but may be a pin or other member. The slit constituting the locked portion 26 engages with one end 26a of the slit when the rod 4c is extended to restrict the movement of the cover portion 22, and allows the movement of the cover portion 22 when the rod 4c is contracted. Length is set to a reasonable length. When the locked portion 26 is formed of a slit, the slit is covered with a protective film such as a cut rubber film 27 that allows movement of the locking portion 25 in order to prevent dust from entering the slit. preferable.

  As another stopper mechanism, as shown in FIG. 3, an axial hole 23a may be formed in the flange 23, and the stopper bar 28 may be passed through the axial hole 23a fixed to the cylinder cap 4b. . Since the stopper rod 28 extends in parallel with the rod 4c, the collar portion 23 can be moved so as to be guided by the stopper rod 28. When the rod 4c extends a predetermined distance, the head of the tip of the stopper rod 28 is moved. The portion 28a abuts on the outer surface of the flange portion 23 and restricts the movement of the cover portion 22. Therefore, in this case, the stopper rod 28 constitutes a locking portion provided in the cylinder body 4ab, and the outer surface of the flange 23 around the axial hole 23a of the flange 23 and the axial hole 23a is the locked portion. Configure.

  As shown in FIG. 4, the stopper mechanism can also be configured by a locking portion 29 fixed to the mounted surface 30 of the hydraulic cylinder 4 and a locked portion provided on the flange portion 23 of the boot 1. For example, a fork-shaped locking portion 29 that is erected and fixed to the mounted surface 30 can be locked to the flange portion 23. In this case, the outer surface of the flange portion 23 becomes the locked portion. In addition, although not shown, an engagement protrusion that engages with the slit 26 of the cover portion 22 as shown in FIG.

Referring to FIG. 5, the hydraulic cylinder 4, for example, for attachment to the mounting surface 30 of the web plate or the like of the rear axle beam, and a mounting portion 4b _1, such as the fixing seat of the cylinder cap 4b.

When the attachment portion 4b ₁ hinders the movement of the cover portion 22, as shown in FIG. 5, the attachment portion 4b ₁ extends from the other end of the cover portion 22 along the axial direction so as not to interfere with the cover portion 22. A notch 31 that is open at one end can be formed. There are various types of attachment portions of the hydraulic cylinder 4 to the attachment surface 30, and notches having a width dimension and a length dimension corresponding to the attachment portion aspect are formed.

On the relationship between the mounting portions 4b ₁ of the hydraulic cylinder 4 is located on the mounting surface side, notches 31 are provided on the side of the mounting surface 30 of the hydraulic cylinder 4, since not exposed to the outside, difficult to enter the dust. Further, by disposing the notch portion 31 close to the attached surface 30, the gap between the notch portion 31 and the attached surface 30 can be reduced, and the entry of dust can be reduced.

  As is clear from the above description, the fluid pressure cylinder equipped with the boot 1 having the above-described configuration has a maximum extension distance of the bellows-like cylindrical portion 21 shorter than the stroke length Lmax of the rod 4c. It is possible to reduce the outer diameter dimension of the battery and to install it in a narrow arrangement space. Since the cover portion 22 covers the rod portion that cannot be covered with the tubular portion 21 when the rod is extended by shortening the tubular portion 21, it is possible to prevent dust from adhering to the rod 4c.

  The present invention is not limited to the above embodiment, and can be modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Boot 21 Cylindrical part 22 Cover part 23 Gutter part 4 Fluid pressure cylinder 4a Cylinder tube 4b Cylinder cap 4ab Cylinder main body 4b ₁ Attachment part 4c Rod 25 Engagement part 26 Engagement part 28 Stopper rod 29 Engagement part 30 Attachment Surface 31 Notch

Claims (4)

A telescopic bellows that is extrapolated to the rod of the fluid pressure cylinder, the length at the time of maximum extension is shorter than the stroke length of the rod, and a cylindrical portion whose one end is fixed to the rod end;
A cover that is movably covered on the cylinder body;
A flange that connects the other end of the cylindrical part and one end of the cover part, and can contact the cylinder cap of the fluid pressure cylinder;
A fluid pressure cylinder boot comprising: The mounting part for mounting the fluid pressure cylinder to the mounting surface and the bellows shape that can be extended and retracted by the rod of the fluid pressure cylinder, and the length at the maximum extension is shorter than the stroke length of the rod, and one end is the rod end A cylindrical portion fixed to the cylinder body, a cover portion that is movably covered by the cylinder body, and the other end of the cylindrical portion and one end of the cover portion can be connected to contact the cylinder cap of the hydraulic cylinder A fluid pressure cylinder comprising: a flange portion; and a notch portion extending in the axial direction from the other end of the cover portion and formed to avoid interference with the mounting portion. A bellows shape that can be extended and retracted by a rod of a fluid pressure cylinder, has a maximum extension length shorter than the stroke length of the rod, and one end is fixed to the rod end, and can be moved to the cylinder body A boot provided with a cover part, a flange part that connects the other end of the cylindrical part and one end of the cover part, and can contact a cylinder cap of the fluid pressure cylinder;
A stopper mechanism for restricting the amount of movement of the cover part within a predetermined range and extending the cylindrical part when the rod is extended,
The fluid pressure cylinder according to claim 1, wherein the stopper mechanism includes a locking portion provided in a cylinder body of the fluid pressure cylinder and a locked portion provided in at least one of the cover portion and the flange portion. A bellows shape that can be extended and retracted by a rod of a fluid pressure cylinder, has a maximum extension length shorter than the stroke length of the rod, and one end is fixed to the rod end, and can be moved to the cylinder body A boot provided with a cover part, a flange part that connects the other end of the cylindrical part and one end of the cover part, and can contact a cylinder cap of the fluid pressure cylinder;
A stopper mechanism for restricting the amount of movement of the cover part within a predetermined range and extending the cylindrical part when the rod is extended,
The stopper mechanism includes a locking portion provided on a mounting surface of the fluid pressure cylinder, and a locking portion provided on at least one of the cover portion and the flange portion. Rod protection structure.

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