JP3845600B2 - Cylinder rod lashing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylinder rod securing device for locking movement of a cylinder rod with respect to a cylinder tube in, for example, a hydraulic cylinder.
[0002]
[Prior art and problems to be solved by the invention]
In the case of a hydraulic cylinder that drives a heavy object, a change in volume occurs in the hydraulic oil in the cylinder tube with a change in load applied to the hydraulic cylinder, and it is inevitable that the cylinder rod moves relative to the cylinder tube.
[0003]
In order to suppress the movement of the cylinder rod, if the pressure receiving area of the piston is increased, there is a problem that the apparatus is increased in size.
[0004]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a cylinder rod lashing device that locks the movement of the cylinder rod relative to the cylinder tube.
[0005]
[Means for Solving the Problems]
The first invention is applied to a cylinder rod lashing device for locking the movement of the cylinder rod with respect to the cylinder tube.
[0006]
Then, a circular cylindrical metal deformation tube you face the outer peripheral surface of the cylinder rod, and a pressure chamber formed around the deformed tube, and the deformation tube is thin-walled cylindrical seat屈筒section, this The buckling tube portion has an annular collar portion formed at both ends of the buckling tube portion. It was set as the structure pressed against a surface.
The deformation tube is configured to buckle and deform by the pressure introduced into the pressure chamber.
[0007]
According to a second invention, in the first invention, a pressure deformation restricting portion facing the outer peripheral surface of the deformable tube is provided.
[0009]
Operation and effect of the invention
According to the first invention, when a predetermined pressure is introduced into the pressure chamber, the deformable tube expands inward, and the bulging portion of the deformable tube is pressed against the outer peripheral surface of the cylinder rod, and the outer peripheral surface of the cylinder rod is secured. To do. For this reason, the movement of the cylinder rod relative to the cylinder tube can be locked over the entire stroke by adjusting the pressure guided to the pressure chamber.
[0010]
And it becomes possible to define a pressure chamber with a deformation | transformation tube itself, and simplification of a structure is achieved. And it becomes possible to form a deformation | transformation tube with a metal, the surface rigidity is ensured, and sufficient durability is acquired.
[0011]
According to 2nd invention, when a deformation | transformation tube contact | abuts to a pressure deformation control part, it controls that a deformation | transformation tube deform | transforms excessively.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0014]
As shown in FIG. 1, the hydraulic cylinder 10 includes a cylindrical cylinder tube 12, an oil chamber 14 defined by a piston (not shown) inside the cylinder tube 12, and one end of the cylinder tube 12 coupled to the piston. A protruding cylinder rod 11 and a cylinder head 13 that slidably supports the cylinder rod 11 with respect to the cylinder tube 12 are provided. The oil chamber 14 is connected to a hydraulic circuit (not shown), and the cylinder rod 11 is moved by the hydraulic pressure applied to the piston, so that the hydraulic cylinder 10 is expanded and contracted.
[0015]
The hydraulic cylinder 10 includes a tying device 130 for the cylinder rod 11 that locks the movement of the cylinder rod 11 with respect to the cylinder tube 12, and stops the expansion and contraction operation of the hydraulic cylinder 10. The lashing device 130 is provided on the opening end side of the cylinder tube 12 and allows the cylinder rod 11 to pass therethrough.
[0016]
As shown in FIG. 2, the lashing device 130 includes an outer block 131 fixed to the cylinder tube 12 via the cylinder head 13, a deformation tube 141 interposed in the outer block 131, and the outer block 131 and the deformation. An inner block 151 interposed between the tubes 141 and a retainer 161 fastened to the open end of the outer block 131 are provided. The outer block 131 is a strength member and forms the main body of the securing device 130. The annular retainer 161 is fastened to the outer block 131 via a plurality of bolts 162, and fixes the inner block 151 between the outer block 131.
[0017]
The metal deformable tube 141 includes a thin cylindrical buckling tube portion 142 and annular collar portions 143 formed at both ends of the buckling tube portion 142 by machining. The buckling tube portion 142 has an inner diameter of about 130 mm, whereas its plate thickness t is, for example, about 0.8 mm. As a material of the deformable tube 141, for example, stainless steel, aluminum, or brass is used.
[0018]
A pressure chamber 144 is formed between the outer block 131 and the deformation tube 141, and buckling deformation in which the buckling tube portion 142 swells inward by the hydraulic pressure guided to the pressure chamber 144 is performed to bind the outer peripheral surface of the cylinder rod 11. It is supposed to be.
[0019]
Two O-rings 145 are interposed between the outer block 131 and each collar 143 of the deformation tube 141, and the pressure chamber 144 is sealed by the O-rings 145.
[0020]
An oil passage 132 communicating with the pressure chamber 144 is formed in the outer block 131. High pressure and low pressure are selectively guided to the pressure chamber 144 via a hydraulic circuit (not shown).
[0021]
The inner block 151 is divided into a semi-annular shape, and is interposed between the outer block 131 and the deformation tube 141. The inner peripheral surface of the inner block 151 is opposed to the buckled tube portion 142 as a pressure deformation restricting portion with a gap s. A through hole 152 is formed in the inner block 151, and the pressure chamber 144 and the oil passage 132 are communicated with each other through the through hole 152.
[0022]
Next, the operation will be described.
[0023]
When high pressure is introduced into the pressure chamber 144, the buckling tube portion 142 of the deformation tube 141 is elastically deformed inward by the hydraulic pressure of the pressure chamber 144, and then buckled and deformed in a vertical stripe shape. The protruding portion is pressed against the outer peripheral surface of the cylinder rod 11 to stop the movement of the cylinder rod 11 relative to the cylinder tube 12.
[0024]
At this time, the deformable tube 141 can be pressurized until a large number of vertical stripes are generated in the buckled tube portion 142. The difference between the buckling pressure and the pressure at the time of elastic deformation at the time of contact becomes an effective pressure ΔP, and the cylinder rod 11 is compressed. This effective pressure ΔP slightly decreases due to the rigidity of the cylinder rod 11. The product of the effective pressure ΔP and the effective area A of the deformation tube 141 is the contact force F.
[0025]
For example, when the pressure during elastic deformation is 50 kgf / cm ² and the pressure during buckling deformation is 20 kgf / cm ² , the effective pressure ΔP is calculated by the following equation.
ΔP≈ (50−20) × 0.8 = 24 kgf / cm ² (1)
When the inner diameter of the deformation tube 141 is 13.12 cm and the effective buckling length is 3.0 cm, the effective area A is calculated by the following equation.
A≈13.12 × (π / 4) × 3.0 = 404 cm ² (2)
The total contact force F is calculated by the following formula.
F = ΔP × A≈9700 kgf (3)
When the friction coefficient μ between the deformation tube 141 and the cylinder rod 11 is 0.2, the locking force Fs is calculated by the following equation.
Fs = F · μ = 1940 kgf (4)
Therefore, the locking force Fs can be about 2000 kgf, and the cylinder rod 11 can be secured sufficiently.
[0026]
On the other hand, when the tank pressure is guided to the pressure chamber 144, the buckled tube portion 142 of the deformation tube 141 returns to its original shape, and the cylinder rod 11 is released from being locked.
[0027]
The deformation tube 141 receives pressure and expands in diameter, but when it comes into contact with the inner block 151, further deformation is stopped and the shape of the inner wall surface of the cylinder tube 12 is maintained. As a result, troubles caused by excessive deformation of the deformation tube 141 are avoided.
[0028]
Since the deformation tube 141 itself defines the pressure chamber 144, the structure can be simplified. And the deformation | transformation tube 141 is formed with a metal, the surface rigidity is ensured and sufficient durability is acquired.
[0029]
Next, reference examples shown in FIGS. 3 and 4 will be described. In addition, the same code | symbol is attached | subjected to the same structure part as the said embodiment.
[0030]
The lashing device 130 includes a metal deformation tube 171 for lashing the outer peripheral surface of the cylinder rod 11 and a resin lashing tube 181 for tightening the deformation tube 171 by pressure guided to the pressure chamber 144.
[0031]
The metal deformable tube 171 is formed with a longitudinal groove 172 having a predetermined width along the axial direction, and is tightened by the lashing tube 181 so that the opening width of the longitudinal groove 172 is reduced to reduce the diameter. ing.
[0032]
Cylindrical spacers 173 and 174 are provided side by side with the deformation tube 171 in the axial direction. The deformed tube 171 is sandwiched between cylindrical spacers 173 and 174 at both ends.
[0033]
The lashing tube 181 is formed into a cylindrical shape by machining using MC nylon, and a pressure chamber 144 is formed between the tying tube 181 and the outer block 131.
[0034]
Two O-rings 145 are interposed between the outer block 131 and the securing tube 181, and the pressure chamber 144 is sealed by the O-rings 145.
[0035]
When the discharge pressure from the hydraulic pump 135 is guided to the pressure chamber 144, the tying tube 181 tightens the deformation tube 171, and the inner peripheral surface of the deformation tube 171 is pressed against the outer peripheral surface of the outer peripheral surface of the cylinder rod 11. The movement of the cylinder rod 11 with respect to 12 is locked.
[0036]
By forming the deformable tube 171 from metal, the surface rigidity is ensured and sufficient durability is obtained.
[0037]
By deforming the deformable tube 171 by expanding and contracting the opening width of the longitudinal groove 172, it is possible to increase the amount of deformation of the inner peripheral surface, and the cylinder rod 11 can be securely bound. The deformation tube 171 can secure a deformation amount of about 1%. For example, when the inner diameter is about 100 mm, a deformation amount of about 1 mm can be secured.
[0038]
As another reference example, as shown in FIG. 5, the longitudinal groove 172 may be formed to be inclined with respect to the axial direction of the deformable tube 171.
[0039]
In this case, the deformation tube 171 is deformed while keeping its cross section circular, so that the deformation amount of the inner peripheral surface can be increased, and even when the cylindrical portion 42 of the cylinder rod 11 is formed of a resin material. The cylinder rod 11 can be securely secured.
[0040]
As another reference example, as shown in FIG. 6, the securing tube 182 may be formed into a cylindrical shape by using a fluororesin as a material. A lip portion 183 that is in contact with the outer block 131 is integrally formed, and the pressure chamber 144 is sealed.
[0041]
In this case, by forming the tying tube 182 with a fluororesin, heat resistance and durability can be improved, and the structure can be simplified by eliminating the O-ring.
[0042]
Note that the lashing device of the present invention is not limited to a hydraulic cylinder, but can be applied to other hydraulic cylinders or air cylinders.
[0043]
The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a hydraulic cylinder showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the lashing device.
FIG. 3 is a cross-sectional view of a securing device showing a reference example .
FIG. 4 is a perspective view of a deformed tube and the like.
FIG. 5 is a perspective view of a deformed tube or the like showing a reference example .
FIG. 6 is a cross-sectional view of a securing device showing a reference example .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Hydraulic cylinder 11 Piston rod 12 Cylinder tube 130 Clamping device 141 Deformation tube 142 Buckling cylinder part 144 Pressure chamber 151 Inner block (Pressure deformation control part)

Claims (2)

In a cylinder rod lashing device that locks movement of a cylinder rod with respect to a cylinder tube, a cylindrical metal deformation tube facing the outer peripheral surface of the cylinder rod, and a pressure chamber formed around the deformation tube The deformation tube has a thin cylindrical buckling tube portion and annular collar portions formed at both ends of the buckling tube portion, and the buckling tube portion is caused by pressure guided to the pressure chamber. A cylinder rod lashing device characterized in that a large number of bulging portions are pressed against the outer peripheral surface of the cylinder rod by buckling deformation bulging inward . The cylinder rod lashing device according to claim 1, further comprising a pressure deformation restricting portion facing the outer peripheral surface of the deformation tube.

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