CN104214165B - A kind of dual-port support lock locking oil cylinder and controlling method thereof - Google Patents

Abstract

The invention relates to a dual-port support locking oil cylinder, which includes a cylinder barrel, an upper end cover, a lower end cover and a guide sleeve fixed on the cylinder barrel, and the upper end cover, the lower end cover, the guide sleeve and the cylinder barrel form a cavity for holding There is a piston rod assembly in the cavity, and a piston and a locking sleeve are set on the piston rod assembly from top to bottom. The locking sleeve is in interference fit with the cylinder, and the upper end of the cylinder is provided with a grease nozzle to control the movement of the cylinder. The lower end of the cylinder is provided with a lower nozzle for controlling the action of the oil cylinder and unlocking the oil cylinder. The invention also relates to a control method for a double-port support locking oil cylinder. A dual-port support locking oil cylinder of the present invention simplifies the oil circuit, reduces the cost, improves the reliability and effective stroke, and the working state of the cylinder barrel is better when unlocked, and it is not easy to wear and tear, so that the application More convenient and reliable.

Description

A dual-port support locking cylinder and its control method

technical field

The invention relates to a dual-port support locking oil cylinder and a control method thereof.

Background technique

Many engineering applications require actuating elements with small size, large thrust and precise positioning, and hydraulic cylinders (hydraulic cylinders) with any position locking function are a good choice, so they are widely used in automobiles, trailers, Support and locking of trailers and other mobile carriers.

Hydraulic cylinders with the above functions are divided into steel ball self-locking cylinders and interference-type locking cylinders according to the locking principle. The steel ball self-locking cylinder relies on the friction self-locking between the steel ball installed on the inner slope of the piston and the cylinder to lock the piston. This kind of cylinder has two working oil ports and does not need a special unlocking oil port. The working method is the same as The ordinary oil cylinder is the same, and the hydraulic oil circuit is also the same as the ordinary oil cylinder, so it is more convenient to use, but the inner wall of this oil cylinder is easily deformed, the locking force is limited, and the application range is limited. The interference locking cylinder relies on the friction force generated by the interference fit between the piston and the cylinder or between the piston rod and the cylinder to lock the piston or piston rod, as shown in Figure 1. This type of cylinder has a large locking force, but it needs to be configured Only three oil ports can work, one oil port is dedicated to unlocking, and the other two oil ports are used for motion control, and unlocking and motion control are independent of each other.

When the interference type locking cylinder is used as a support cylinder, it is generally installed around a large vehicle, and the distance from the hydraulic source is relatively long, so the connecting pipeline is long, and the position of the support point needs to be movable, so a hose is required. Therefore, the three oil ports of the supporting cylinder need to be connected from the hydraulic source to the hydraulic source through multi-section hard pipes and hoses. The complexity of connecting pipelines increases the number of hydraulic system connectors, increases the number of nodes where oil leakage occurs, and reduces system reliability. Moreover, since pipelines are often installed on parts that are difficult to maintain such as the bottom of the vehicle, it is difficult to deal with problems such as oil leakage. .

Contents of the invention

Purpose of the invention: The purpose of the invention is to overcome the deficiencies in the prior art and provide a convenient and reliable dual-port support locking cylinder and its control method.

Technical solution: The present invention is a dual-port support locking oil cylinder, including a cylinder barrel and an upper end cover, a lower end cover and a guide sleeve fixed on the cylinder barrel, and the upper end cover, the lower end cover, the guide sleeve and the cylinder barrel form a cavity , there is a piston rod assembly in the cavity, and a piston and a locking sleeve are set on the piston rod assembly from top to bottom. The locking sleeve and the cylinder have an interference fit. Oil nozzle, the lower end of the cylinder barrel is provided with a lower oil nozzle for controlling the action of the oil cylinder and unlocking the oil cylinder.

Preferably, it also includes a lock nut and a seal ring, the piston is fixedly connected to the piston rod assembly through the lock nut, the inner circumference and outer circumference of the piston are respectively provided with seal rings and the cavity is separated into a rod cavity and a rodless cavity; The outer periphery of the locking sleeve is provided with a spiral groove communicating with the rod cavity.

Preferably, the piston rod assembly is a hollow stepped cylinder that is thinner at the top and thicker at the bottom, the piston rod assembly has a smaller diameter part sleeved with a piston, and the larger diameter part constitutes a moving piston rod.

Preferably, the outer diameter of the moving piston rod and the inner diameter of the cylinder meet the relationship π(R ² −r ² )<0.2×πR ² , where R is the inner diameter of the cylinder, and r is the outer diameter of the moving piston rod.

Preferably, the outer diameter of the moving piston rod and the inner diameter of the cylinder satisfy the relationship

0.1×πR ² <π(R ² -r ² )<0.2×πR ² , where R is the inner diameter of the cylinder, and r is the outer diameter of the moving piston rod.

The present invention also discloses a method for controlling a dual-port support and lock cylinder, which includes the above-mentioned dual-port support and lock cylinder and a hydraulic system connected to the cavity. When the dual-port support and lock cylinder needs to be unlocked, the The high-pressure oil of the hydraulic system enters the cavity from the lower oil nozzle, and the high-pressure oil expands the interference fit part between the cylinder barrel and the locking sleeve and the lower part of the cylinder barrel.

Preferably, the movement of the dual-port support locking cylinder is controlled by two oil sources.

Preferably, the hydraulic system includes a high-pressure oil pump and a low-pressure oil pump, and the high-pressure oil pump provides high-pressure oil under the control of the first two-position electromagnetic reversing valve and the first relief valve and injects it into the lower oil nozzle to realize dual-port support locking The unlocking of the oil cylinder; the low-pressure oil pump provides low-pressure oil and injects it into the oil nozzle under the control of the second two-position electromagnetic reversing valve and the second overflow valve, and the two-port support locking oil cylinder is in the position of the three-position electromagnetic reversing valve. Stretch out when the three-position electromagnetic reversing valve is in the right position, and the retraction speed is adjusted by the throttle valve, and stop moving when the three-position electromagnetic reversing valve is in the middle position.

Beneficial effects: the double-port support locking oil cylinder of the present invention integrates the function of the old unlocking oil port into the motion control oil port, so that only two oil nozzles are needed, the oil circuit is simplified, the cost is reduced, and the reliability is improved; at the same time, because the unlocking High-pressure oil enters the rod cavity from the lower nozzle, so only one upper piston is needed, which greatly simplifies the internal structure and increases the effective stroke. When the double-port support locking oil cylinder of the present invention is unlocked, not only the interference fit part of the cylinder barrel and the locking sleeve is expanded, but also the rod cavity part of the cylinder barrel is expanded, so that the working state of the cylinder barrel is better when unlocked , It is not easy to wear and tear, and the application is more convenient and reliable.

Description of drawings

Figure 1 is a schematic diagram of an existing locking oil cylinder, and c is an unlocking oil port;

Fig. 2 is a schematic diagram of a dual port support locking oil cylinder of the present invention;

Fig. 3 is the oil cylinder control schematic diagram of the present invention;

Fig. 4 is a schematic diagram of comparison of cylinder expansion when the oil cylinder is extended, d1 is the expansion and expansion of the cylinder when the existing oil cylinder is extended, and d2 is the expansion and expansion of the cylinder when the oil cylinder of the present invention is extended.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 2, a double-port support locking cylinder includes a pressure plate 1, a key 2, a cylinder barrel 3, an upper end cover 4, an oil nozzle 5, a lock nut 6, a piston 7, a lock sleeve 8, a piston rod assembly 9, The lower oil nozzle 10, the guide sleeve 11, the flange 12, the lower end cover 13, and the ball head 14; the upper end cover 4, the lower end cover 13, the guide sleeve 11 and the cylinder 3 form a cavity, and a piston rod assembly is arranged in the cavity 9. The piston rod assembly 9 is provided with a piston 7 and a locking sleeve 8 from top to bottom. The locking sleeve 8 is in interference fit with the cylinder 3 to ensure reliable locking of the oil cylinder. The upper end of the cylinder 3 is provided with a The upper oil nozzle 5 for controlling the action of the oil cylinder, and the lower end of the cylinder barrel 3 is provided with a lower oil nozzle 10 for controlling the action of the oil cylinder and unlocking the oil cylinder.

The piston 7 is fixedly connected to the piston rod assembly 9 through the lock nut 6, and the inner and outer circumferences of the piston 7 are respectively provided with sealing rings to isolate the chamber into a rod chamber a and a rodless chamber; the outer periphery of the locking sleeve 8 A spiral groove b communicating with the rod chamber a is provided.

The piston rod assembly 9 is a hollow stepped cylinder that is thinner at the top and thicker at the bottom. The piston 7 is sheathed in the smaller diameter part of the piston rod assembly 9, and the moving piston rod is formed by the larger diameter part.

The outer diameter of the moving piston rod and the inner diameter of the cylinder 3 satisfy the relationship 0.1×πR ² <π(R ² −r ² )<0.2×πR ² , where R is the inner diameter of the cylinder 3 and r is the outer diameter of the moving piston rod.

The upper end cover 4 is used as a stop when the oil cylinder is retracted, and is fixedly connected with the cylinder barrel 3 through the key 2, and the upper end cover 4 is fixed by the pressure plate 1; the guide sleeve 11 is used as a guide when the piston rod moves, and its inner ring A sealing ring is installed to seal the rod cavity a, and the guide sleeve 11 is compressed and fixed by the lower end cover 13 as a stopper when the oil cylinder is extended, and a dust-proof ring is installed on the inner ring of the lower end cover 13; the ball head 14 can be used It is used to install the support chassis, so that the oil cylinder can be adjusted at a certain angle while supporting the load, so as to adapt to the uneven support surface.

The parameter implementation of the dual-port support locking cylinder:

(1) The diameter r of the piston rod should be large enough so that the back pressure generated by the unlocking oil pressure does not affect the extension of the oil cylinder. In order to ensure that the unlocking oil pressure does not produce a large back pressure on the extension of the oil cylinder, the effective area of the rod cavity a S _H ＝π(R ² -r ² ) should be small enough, assuming that the unlocking oil pressure is p _H , then the back pressure generated is (S _H /S _L )p _H , and the area of the rodless chamber is S _L =πR ² , so it should be ensured that π(R ² -r ² )<β×πR ² , where β is the percentage of the area of the rod chamber a to the area of the rodless chamber, the smaller the β, the smaller the back pressure, generally, β= 10% to 20% is appropriate, and it is not that the smaller the β, the better. If the β is too small, the extrusion stress of the locking sleeve 8 and the guide sleeve 11 will be too large when the oil cylinder moves to the end, resulting in the locking sleeve 8 or guide sleeve. 11 The deformation destroys the precise inner circle of the cylinder 3, therefore, the selection of r satisfies the following conditions, and Among them, Ft is the maximum thrust of the oil cylinder, σ _e1 is the smaller value of the elastic limit of the material of the locking sleeve 8 or the guide sleeve 11, n _e1 is the safety coefficient of the elastic deformation of the locking sleeve 8 or the guide sleeve 11, generally _ne1 = 2～4;

(2) The wall thickness δ of the cylinder barrel 3, the design of the wall thickness of the cylinder barrel 3 is very important, it is directly related to the interference amount of the interference fit, according to the theory of elastic mechanics, the relationship between the interference amount ε and the wall thickness is as follows,

$\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}}}{\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; (</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; (</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&mu;</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; R</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&mu;</span>}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>$

Among them, E is the elastic modulus of the material of the cylinder 3, μ is the Poisson's ratio of the material of the cylinder 3, and the following simplified design formula can be obtained from the above relationship At the same time, the design of the wall thickness of the cylinder 3 also needs to meet the following stress conditions,

Among them, σ _e2 is the elastic limit of the cylinder 3 material, n _e2 is the elastic deformation safety factor of the cylinder 3, generally n _e2 = 2~4;

(3) The length L of the locking sleeve 8, the length of the locking sleeve 8 is determined according to the size of the locking force, if the required locking force is F _s , then L=n _s F _S /2πRLp _H f, where f is The coefficient of friction between the cylinder 3 and the locking sleeve 8, n _s is the locking safety factor, which can be determined according to the actual working conditions.

Based on the above-mentioned dual-port support and lock cylinder, the present invention also provides a control method for the dual-port support and lock cylinder: comprising the above-mentioned dual-port support and lock cylinder and a hydraulic system communicating with the cavity, When the support locking oil cylinder needs to be unlocked, the high-pressure oil of the hydraulic system enters the cavity from the lower oil nozzle 10, and the high-pressure oil expands the interference fit part between the cylinder 3 and the locking sleeve 8 and the lower part of the cylinder 3.

See Fig. 3, wherein, described hydraulic system comprises high-pressure oil pump 16 and low-pressure oil pump 17, and the movement of oil cylinder is controlled by two-way oil source, and high-pressure oil pump 16 is in the position of first two-position electromagnetic reversing valve 15 and first relief valve 18. Provide high-pressure oil with constant pressure or unloading under control. When the first two-position electromagnetic reversing valve 15 is in the left position, the high-pressure oil is unloaded and the oil cylinder is in a locked state; when the first two-position electromagnetic reversing valve 15 is in the right position When in position, the high-pressure oil is injected into the lower oil nozzle 10, enters the rod cavity a of the oil cylinder, and then enters the spiral groove b from the outer circle of the lower end surface of the locking sleeve 8. Since the inner and outer circles of the piston 7 are equipped with sealing rings, the oil cylinder has a The rod cavity a and the spiral groove b form a sealed space, and the high-pressure oil will expand the interference fit part of the cylinder 3 and the locking sleeve 8 and the lower part of the cylinder 3 to realize unlocking; the low-pressure oil pump 17 is in the second and second positions Under the control of the electromagnetic reversing valve 19 and the second relief valve 20, low-pressure oil is provided and injected into the oil nozzle 5. When the three-position electromagnetic reversing valve 22 is in the left position, the oil cylinder extends. When the three-position electromagnetic reversing valve 22 is in the left position During the right position, the oil cylinder is retracted, and the speed of retraction is regulated by the throttle valve 21, and when the three-position electromagnetic reversing valve 22 is in the middle position, the oil cylinder stops moving.

The double-port support locking oil cylinder of the present invention integrates the function of the old unlocking oil port c into the motion control oil port, so that only two oil nozzles are needed, the oil circuit is simplified, the cost is reduced, and the reliability is improved; at the same time, because the unlocking high-pressure oil It enters the rod cavity from the lower nozzle, so only one upper piston is needed, which greatly simplifies the internal structure and increases the effective stroke.

As shown in Figure 4, when the double-port support locking cylinder of the present invention is unlocked, not only the interference fit part of the cylinder and the locking sleeve is expanded, but also the rod cavity part of the cylinder is expanded, so that the The working condition is better, it is not easy to wear and tear, and the application is more convenient and reliable.

Claims (8)

1. A double-port support locking oil cylinder, comprising a cylinder barrel (3) and an upper end cover (4), a lower end cover (13) and a guide sleeve (11) fixed on the cylinder barrel (3), the upper end cover ( 4), the lower end cover (13), the guide sleeve (11) and the cylinder (3) form a cavity, and a piston rod assembly (9) is arranged in the cavity, and the piston rod assembly (9) is sleeved from top to bottom There is a piston (7) and a locking sleeve (8), and the locking sleeve (8) is in interference fit with the cylinder (3), and it is characterized in that: the upper end of the cylinder (3) is provided with a grease nozzle for controlling the movement of the oil cylinder (5), the lower end of the cylinder barrel (3) is provided with a lower oil nozzle (10) for controlling the action of the oil cylinder and unlocking the oil cylinder. 2. The double-port support locking oil cylinder according to claim 1, characterized in that: it also includes a lock nut (6) and a sealing ring, and the piston (7) is fixedly connected to the piston rod assembly ( 9), the inner and outer circumferences of the piston (7) are respectively provided with sealing rings and the cavity is separated into a rod cavity (a) and a rodless cavity; the outer circumference of the locking sleeve (8) is provided with a rod cavity (a) a) Connected spiral grooves (b). 3. The double-port support locking oil cylinder according to claim 1, characterized in that: the piston rod assembly (9) is a hollow stepped cylinder with a thinner top and a thicker bottom, and the diameter of the piston rod assembly (9) is smaller The part sleeved with piston (7), the larger part of the diameter constitutes a moving piston rod. 4. The double-port support locking oil cylinder according to claim 3, characterized in that: the outer diameter of the moving piston rod and the inner diameter of the cylinder (3) satisfy the relationship π(R ² -r ² )<0.2×πR ² , Wherein R is the inner diameter of the cylinder barrel (3), and r is the outer diameter of the moving piston rod. 5. The dual-port support locking oil cylinder according to claim 3, characterized in that: the outer diameter of the moving piston rod and the inner diameter of the cylinder (3) satisfy the relationship 0.1×πR ² <π(R ² -r ² )< 0.2×πR ² , where R is the inner diameter of the cylinder (3), and r is the outer diameter of the moving piston rod. 6. A method for controlling a dual-port support and locking cylinder, comprising the dual-port support and locking cylinder according to any one of claims 1 to 5 and a hydraulic system communicating with the cavity, characterized in that: When the port support locking oil cylinder needs to be unlocked, the high-pressure oil of the hydraulic system enters the cavity from the lower oil nozzle (10), and the high-pressure oil will press the cylinder (3) and the interference fit part of the locking sleeve (8) and the cylinder ( 3) The lower part of it is opened. 7. The method for controlling the dual-port support and locking cylinder according to claim 6, wherein the movement of the dual-port support and locking cylinder is controlled by two oil sources. 8. The dual-port support locking oil cylinder control method according to any one of claims 6 or 7, the hydraulic system includes a high-pressure oil pump (16) and a low-pressure oil pump (17), characterized in that: the high-pressure oil pump (16 ) provides high-pressure oil under the control of the first two-position electromagnetic reversing valve (15) and the first relief valve (18) and injects it into the lower oil nozzle (10) to realize the unlocking of the dual-port support locking oil cylinder; the low-pressure oil pump (17) Under the control of the second two-position electromagnetic reversing valve (19) and the second overflow valve (20), low-pressure oil is provided and injected into the oil nozzle (5). The reversing valve (22) protrudes when it is in the left position, and retracts when the three-position electromagnetic reversing valve (22) is in the right position, and the retraction speed is adjusted by the throttle valve (21). ) stops moving when it is in the middle position.