JPH062464B2 - Cylinder-End cover - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end cover of a fluid pressure cylinder, for example, an end cover of a cylinder preferably used for a power steering mechanism of a vehicle.

Prior Art FIG. 1 shows a cylinder in a conventional power steering mechanism of a vehicle.

In the figure, 1 is a cylinder, and 2 is an end cover made of a cold forged product. 3 is the piston of cylinder 1,
Numerals 4 and 5 are oil supply ports for supplying and discharging pressure oil to the left and right of the piston 3 to expand and contract the piston rod 6, respectively.
Is a mechanism for penetrating the end cover 2 and axially supporting the end cover 2 so as to project from the end of the cylinder to the outside so as to be connected to the wheels and transmit the motion.

The end cover 2 is made of a through-walled thick-walled cylindrical body, and is formed at the rear portion by being screwed onto the inner peripheral surface of the cylinder end portion with a male screw 2a fitted on the end portion of the cylinder 1 and formed on the outer peripheral surface. The flange 2b is brought into contact with the end surface of the cylinder to set the screwing tightening amount, and the bush 7 fitted to the inner peripheral surface of the end cover 2 allows the cylinder rod 6 to slide.

Thus, the conventional cylinder end cover 2 is mainly made of the cold forged product as described above with the aim of obtaining the required strength by enriching the rigidity of the parts, but it is not always appropriate from the viewpoint of its function. There are problems that cannot be said.

Problems to be Solved by the Invention That is to say, due to its function, the cylinder end cover 2 is constantly subjected to an excessive axial load due to expansion and contraction of the cylinder rod and a radial load due to deflection of the rod. It is applied in a concentrated manner on the threaded portion of the end cover 2, the flange 2b, the bush 7, etc., and the end cover 2 has high rigidity and lacks an impact absorbing effect, so that fatigue, wear, deformation, etc. of each part easily occur. As a result, the fastening force of the threaded portion may be reduced, and the bush 7 may be damaged.

Means for Solving the Problems The present invention provides a cylinder end cover that eliminates the above-mentioned problems, and as a means thereof, the cylinder end cover is provided on the outer circumference of the inner cylinder from one end of the inner cylinder via a folded back portion. And an outer cylinder integrally formed with each other, and an annular groove is formed between the outer cylinder and the inner cylinder, the annular groove being open on the free end side of the outer cylinder (the end side opposite to the folded-back portion). By similarly fitting the outer cylinder to the inner peripheral surface of the cylinder end portion, the spring effect in the folded-back portion is retained between the outer cylinder and the inner cylinder so that a shock absorbing action for the load is provided. It is composed.

In other words, according to the present invention, the cantilever composite cylinder structure of the cylinder end cover realizes the inner cylinder as a penetrating and supporting cylinder for the cylinder rod, so that the cover during vibration of the rod or the entire cover due to expansion and contraction of the rod can be used. The applied dynamic load is satisfactorily absorbed and buffered by the spring effect in the bent portions of the inner cylinder and the outer cylinder, and damage to the fitting portions such as the bush and the end cover screwing portion can be effectively prevented.

Further, according to the present invention, the cylinder end cover has a cantilevered composite cylinder structure, and the outer cylinder is used as a fitting cylinder for the cylinder end portion, whereby the above spring effect is exerted to obtain a strong fastening force, and a firm fitting is achieved. can get.

Further, according to the present invention, the inner cylinder of the cylinder end cover has a bottom and the end cylinder of the end opposite to the side where the cylinder rod protrudes is used as the end cover. It is possible to expect the same impact absorbing effect as described above.

Further, the present invention is a cantilevered composite cylinder structure in which one end of the inner cylinder and one end of the outer cylinder are continuously provided by a bent back portion, and a flange is provided at the free end of the outer cylinder to lock to the cylinder end surface. Combined with the above effect, the overload of the flange portion can be effectively prevented.

Further, according to the present invention, while the end cover has the above-mentioned cantilevered composite cylinder structure, by bending the stopper seat of the cylinder rod at the free end of the inner cylinder, the impact applied to the inner cylinder end portion due to the expansion and contraction of the rod is reduced. Good absorption and cushioning can be achieved by the elastic action of the cylinder and the disc spring action of the stopper.

Embodiment An embodiment of the present invention will be described below with reference to FIG.

2 and 3 show an embodiment of the cylinder end cover of the power steering mechanism, particularly the cylinder end cover of the piston rod in the cylinder.

As before, 11 is a cylinder, 13 is a piston, 1
Reference numerals 4 and 15 are filler openings, 16 is a piston rod, and 12
Shows a cylinder end cover configured as the piston rod cover.

The cylinder end cover 12 includes an inner cylinder 12a and an outer cylinder 12
It consists of b. The outer cylinder 12b is continuously arranged from one end of the inner cylinder 12a so as to surround the inner cylinder 12a via the folded-back bent portion 12c, and is arranged concentrically with each other.

The outer cylinder 12b has an end opposite to the folded-back portion 12c as a free end, and the outer cylinder 12b and the inner cylinder 12a are connected to the folded-back portion 12c.
They are cantilevered with each other via c. That is, the cylinder end cover 12 has a cantilevered composite cylinder structure of an inner cylinder 12a and an outer cylinder 12b, and an annular gap 12h that opens on the free end side is formed between the inner cylinder 12a and the outer cylinder 12b. Inner cylinder 12
The can and the outer cylinder 12b are elastically displaceable at the cantilever portion (folded bent portion 12c).

The inner cylinder 12a functions as a cylinder insertion support cylinder, has a penetrating structure as shown in the figure, and has an end opposite to the folded-back bent portion 12c as a free end like the outer cylinder 12b.
The free end of the inner cylinder 12a (the end on the protruding side of the cylinder rod 16) is bent in the radial direction, that is, the centripetal direction (toward the cylinder rod 16), and the stop seat 1 of the cylinder rod 16 is bent.
2e is formed. The lower part of the neck of the stopper 12e is fixed to the stopper 12e.
The diameter of the constricted portion 12f is smaller than the diameter.

On the other hand, an annular stopper 16a that abuts the stop seat 12e is formed on the outer circumference of the cylinder rod 16. When the stopper 16a is contracted, the stopper 16a hits the stop seat 12e to set the most contracted position. The stop seat 12e has elasticity in the cylinder rod axial direction with the curved portion as a fulcrum, and at the same time has elasticity in the same radial direction by the constricted portion 12f, that is, in the outward direction, and the impact when the cylinder rod 16 contracts. Absorb and buffer.

In addition, the free end of the outer cylinder 12b is bent in the radial direction, that is, the outer peripheral direction (toward the cylinder 11), and the cylinder 11 is bent.
A flange 12d that is abuttingly locked to the end face of the.

The axial impact (load) applied to the cylinder end cover 12, particularly the impact when the cylinder rod 16 contracts, is applied to the stopper seat 12e of the inner cylinder 12a and the inner and outer cylinders 12a and 12b.
The flange 12d receives and buffers while obtaining the elastic buffering effect.

As described above, the cylinder end cover 12 is fitted to the inner peripheral surface of the end portion of the cylinder 11 with the outer cylinder 12b,
The cylinder rod 16 is inserted into the inner cylinder 12a and is slidably engaged with the bush 17 fitted in the stepped hole portion 12i formed on the inner peripheral surface of the inner cylinder 12a. Reference numeral 18 denotes a sealing disposed on the inner end surface of the cylinder of the folded back portion 12c of the cylinder end cover 12.

Thus, the inner cylinder 12a supports the cylinder rod 16 via the bush 17, the outer cylinder 12b supports the inner cylinder 12a at the end inner peripheral surface of the cylinder 11 via the folded back portion 12c, and the cylinder rod 16 is indirectly connected. Support.

As described above, the inner cylinder 12a and the outer cylinder 12b are formed by the folded-back portion 12
It has a spring effect through c, and absorbs and buffers a radial radial ordinary load and impact when the cylinder rod operates.

At the same time, the spring effect is exerted on the inner peripheral surface of the cylinder end portion to exert an interference fit effect to firmly fit the outer cylinder 12b to the inner peripheral surface of the cylinder end portion.

A male screw 12g is formed on the outer peripheral surface of the outer cylinder 12b and is screwed and fitted to the inner peripheral surface of the cylinder end portion. The cylinder end cover 12 produces the spring effect as described above due to the cantilever composite cylinder structure, and produces a strong fastening force of the screwed portion by the outer cylinder 12b.

2 and 3, the cylinder end cover 12 has a cantilevered composite cylinder structure and is screwed onto the inner peripheral surface of the end of the cylinder 11 to support the cylinder rod 16 in the inner cylinder 12a. Stopper 12 at the free end of the inner cylinder 12a
Reference numeral e'shows an embodiment in which the end surface of the bush 17 is directly supported.

Further, FIG. 4B shows a case in which a sealer 18C that is in contact with the rod 16 is provided on the surface of the stopper seat 12e ″ that faces the cylinder rod 16.

FIG. 5 shows another example. The above-mentioned embodiment shows the case where the inner cylinder 12a and the outer cylinder 12b of the cylinder end cover 12 are fitted so that the free ends thereof are located on the cylinder end face side. A cantilevered composite cylinder structure of 12a and an outer cylinder 12b is inserted, and this is reversely inserted so that the free ends of the inner cylinder 12a and the outer cylinder 12b face inward of the cylinder. Cylinder end cover 1
Numeral 2 is a fixed screw and a load receiving member which is screwed onto the inner peripheral surface of the cylinder with a male screw 12g formed on the outer peripheral surface of the outer cylinder 12b so that the end surface of the outer cylinder 12b abuts against a step formed on the inner peripheral surface of the cylinder. It is used as a seat surface, and the folded back bent portion 12c is positioned on the cylinder end surface side to serve as a stop seat for the cylinder rod 16. Further, a sealing 18 is provided on the inner peripheral surface of the free end of the inner cylinder and the outer peripheral surface of the free end of the outer cylinder.
a and 18b are applied.

Further, FIG. 6 exemplifies a case where the end cover 12 is used as the cylinder rod penetrating support cylinder in each of the above-described embodiments, but the cover is mounted on the side where the rod does not project. As shown in the figure, the cylinder end cover 12 has an inner cylinder 12a.
The outer cylinder 12b is bent from one end of the inner cylinder 12b through the folded back portion 12c to form a cantilevered composite cylinder structure, and the end of the inner cylinder 12b opposite to the folded back portion 12c is bottomed. 12j shows the inner cylinder bottom wall. The end cover 12 is fitted to the end of the cylinder so that the free end of the outer cylinder 12b and the bottom wall 12j of the inner cylinder 12a face inward of the cylinder, and a male screw 12g is formed on the peripheral surface of the outer cylinder 12b. Tightening is performed by screwing, and the end surface of the free end portion of the outer cylinder is abutted against the stepped portion formed on the inner peripheral surface of the cylinder to form a load bearing surface, and a sealing 18d is provided on the load bearing surface.

By the above, the inner cavity of the bottomed inner cylinder 12a is opened to the outside of the cylinder, and this is used as a cylinder mounting cylinder or the like. A female screw 12k for mounting the cylinder is formed on the inner peripheral surface of the bottomed inner cylinder 12a.

Also according to the above, the end cover 12 can be expected to have a spring effect in the folded-back portion 12c of the inner cylinder 12a and the outer cylinder 12b, and exerts good shock absorption and cushioning action.

EFFECTS OF THE INVENTION As described above, the cylinder end cover according to the present invention has the cantilevered composite cylinder structure, and the inner cylinder and the outer cylinder exert the spring effect through the folded-back bent portions, and are mounted when the cylinder rod is operated. Good shock absorption and cushioning.

At the same time, the outer cylinder exerts a good interference fit effect on the inner peripheral surface of the cylinder due to the above spring effect, and there is no fear that the outer cylinder, and thus the cylinder end cover, will be loosened by screwing on the inner peripheral surface of the cylinder. It can be fitted extremely firmly.

By performing the inner cylinder as a cylinder rod penetration support cylinder as described above, deflection during operation of the rod,
Or, the dynamic load applied to the entire cover due to the expansion and contraction of the rod is well absorbed and buffered by the spring effect in the folded portion of the inner cylinder and the outer cylinder, and the wear of the fitting portion such as the bush and the end cover screwing portion, Damage, etc. can be effectively prevented.

Further, the present invention has the inner cylinder of the cylinder end cover with a bottom,
By implementing this as an end cover at the end opposite to the side where the cylinder rod projects, the inner cylinder can be used as a cylinder mounting and fixing part, and the same shock absorbing effect as above can be expected.

Further, according to the present invention, a flange is provided on the free end of the outer cylinder of the cylinder end cover having the above-mentioned cantilever composite cylinder structure so as to engage with the cylinder end surface. The load can be prevented well,
A good spring effect of the inner cylinder and the outer cylinder is generated.

Further, according to the present invention, while the end cover has the above-mentioned cantilevered composite cylinder structure, by bending the stopper seat of the cylinder rod at the free end of the inner cylinder, the impact applied to the inner cylinder end portion due to the expansion and contraction of the rod is reduced. Good absorption and cushioning can be achieved by the elastic action of the cylinder and the disc spring action of the stopper. Further, since it has a composite cylinder structure of an inner cylinder and an outer cylinder and an annular wall is formed between both cylinders to form an elastic structure, there is an advantage that the structure can be lightened.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a cylinder and its end cover in a conventional vehicle power steering mechanism, FIGS. 2 and subsequent figures show an embodiment of the present invention, and FIG. 2 is the same power steering mechanism. 3 is a sectional view showing a cylinder and its end cover in FIG. 3, FIG. 3 is a sectional view of the cylinder end cover, FIG. 4A is a sectional view of a cylinder and its end cover showing another example, and FIG. Sectional view, fifth
FIG. 6 is a sectional view showing still another example, and FIG. 6 is a sectional view showing still another example. 11 ... Cylinder, 12 ... Cylinder end cover, 1
2a ... inner cylinder, 12b ... outer cylinder, 12c folded back portion, 12d
... Flange, 12e, 12e ', 12e "... Cylinder rod stop, 12g ... Male screw, 12h ... Annular gap, 1
2j ... inner cylinder bottom wall, 16 ... cylinder rod, 17 ... bush.

Claims (5)

[Claims] 1. A cylinder end cover fitted on the inner peripheral surface of a cylinder end portion, wherein an outer cylinder surrounding the inner cylinder is connected to one end of the inner cylinder through a folded back portion, and the outer cylinder is folded back. A structure in which an end portion on the opposite side of the curved portion is a free end, and an annular gap is formed between the outer cylinder and the inner cylinder so as to open on the free end side, and the outer cylinder is fitted on the inner peripheral surface of the cylinder end portion. Cylinder end cover characterized by 2. A cylinder end cover according to claim 1, wherein the inner cylinder has a penetrating structure to form a cylinder rod penetrating support cylinder. 3. The cylinder end cover according to claim 1, wherein the inner cylinder has a bottom at the end opposite to the folded-back portion of the outer cylinder. 4. The cylinder end cover according to claim 1, wherein a flange portion that is engaged with the cylinder end surface is bent and formed at the free end of the outer cylinder. 5. The inner cylinder has a penetrating structure to form a cylinder rod penetrating support cylinder, and a stopper for the cylinder rod is formed into an annular bent shape at the end of the inner cylinder on which the cylinder rod protrudes. The cylinder end cover according to claim 1.