RU2012799C1 - Device for control of unit to comply with bed undulation - Google Patents

Abstract

FIELD: mining industry. SUBSTANCE: guides of working member are rigidly connected to one arm of bell-cranks and control hydraulic cylinders are articulated to the other arm of bell-cranks. One bell-crank is hinged to roofing and the other, to conveyer bracket. Hydraulic cylinders are communicated with delivery and return hydraulic lines. Installed inside rod of each control cylinder in cylindrical cavity closed at both ends is plunger spring-loaded at both ends for reciprocation. Diameter of plunger lower end is larger than that of its upper end. End faces and recess of plunged form together with cylindrical cavity, the lower, upper and intermediate chambers. Lower chamber is hydraulic connected with head end of hydraulic cylinder by means of constant throttle. Upper chamber is communicated through rod channel with rod end of hydraulic cylinder. Intermediate chamber is communicated through rod additional chamber with return hydraulic line. EFFECT: higher efficiency. 2 cl, 2 dwg

Description

 The invention relates to the mining industry, and in particular to units for the extraction of coal seams.

 A device for controlling a mining unit, including sections of cylindrical guides for the movement of the annular actuator, the connection of which with the levers is made using elastic bushings.

 The disadvantage of this device is that the use of elastic sleeves does not provide effective protection against shock loads under the action of plow carriages on the guides in places of their kink with complex hypsometry due to the small relative possible displacements of the guides and levers.

 Closest to the technical nature of the proposed device is a device that includes sections of articulated cylindrical guides of the annular actuator with plow carriages, rigidly connected with sections of the guides of the two-arm levers pivotally connected to the rods of control cylinders. In turn, the control cylinders are connected to the eyes with the brackets of the downhole conveyor or the overlapping sections of the lining [1].

 The disadvantage of this device is its increased rigidity, due to the practical incompressibility of the working fluid, locked in the piston and rod cavities of the off control cylinder, which leads to an increase in shock loads when plow carriages act on the guides in the places where their sections rotate relative. As a result, the reliability of the unit decreases, the wear of the plow carriage rollers and guides increases.

 The purpose of the invention is to increase the reliability of the control device by reducing shock loads arising from the movement of plow carriages of the Executive body guide.

 This goal is achieved by the fact that in the closed at the ends of the cylindrical cavity inside the rod of the control cylinder is placed with the possibility of axial movement of the plunger with a groove, and the diameter of the first end of the plunger is larger than the diameter of the second end of this plunger. The first, second end face of the plunger and its groove form the lower, upper and intermediate chambers with a closed cylindrical cavity. The lower chamber is connected through a permanent hydraulic throttle to the piston cavity of the control cylinder, and the upper chamber is connected through the channel in the rod to the rod cavity of this hydraulic cylinder. An intermediate chamber with an additional channel in the rod is connected to a drain hydroline. Between the ends of the cylindrical cavity and the plunger are placed elastic elements in the form of springs. Moreover, the diameter of the second end of the plunger is associated with the diameter of its first end, as well as with the diameters of the piston and rod of the hydraulic control cylinder of a certain analytical dependence.

 A comparative analysis of the proposed solution with the prototype shows that the claimed solution is characterized by the above features, due to which the achievement of the purpose of the invention is achieved. Therefore, the claimed solution meets the criteria of the invention of "novelty."

 The early use of the indicated in their certain relationship in the control devices of mining units was not known.

 Due to these differences from the prototype, it is possible to oscillate the rod with the piston of the control cylinder with locked hydraulic lines connected to the control cylinder, and it increases the reliability of the control device by reducing the impact of plow carriages on sections of cylindrical guides in places of their relative rotation in accordance with the gypsum - Rye coal seam.

 In FIG. 1 shows a control device of a mining unit in a formation profile; in FIG. 2 is a section along AA in FIG. 1.

 The device contains sections of hydraulic guides 1 of the actuator with plow carriages 2. Each of the section guides 1 is rigidly connected to one end of the two-arm lever 3, the other arm of which is pivotally mounted on the rod 4 of the control cylinder 5. The latter is connected to the bracket of the face conveyor 6 or overlap 7 of the section hold on. The middle part of the two-arm lever 3 is also pivotally connected to the conveyor 6 or overlapping 7 of the lining section. Each control cylinder 5 of hydraulic lines 8 and 9 through a hydraulic lock and control valve (not shown) is connected to the pressure and drain hydraulic lines.

A plunger 10 with a groove is placed inside the rod 4 in a cylindrical cavity closed at the ends, with a groove, the diameter D _{1 of the} first end 11 of the plunger 10 being larger than the diameter d _{1 of the} second end 12. Between the ends 11 and 12 of the plunger 10 and the ends of the closed cylindrical cavity are elastic elements, made in the form of lower 13 and upper 14 springs.

 A plunger with a groove together with a closed cylindrical cavity form the lower 15, upper 16 and intermediate 17 of the chamber.

/D .The lower chamber 15 is connected through a permanent hydraulic throttle 18 to the piston cavity 19 of the control cylinder 5, the diameter of which is D. The upper chamber 16 is connected to the rod cavity 21 of the control cylinder 5 by a channel 20 in the stem 4, the diameter of the latter being d, and the intermediate chamber 17 additional channel 22 is connected directly to the drain hydroline. The diameter d _{1 of the} second end face 12 of the plunger 10 is associated with the diameters D ₁ , D and d dependence
d ₁ = D

/ D.

 The operation of the control device of the extraction unit is as follows. When the working fluid is supplied under pressure through hydraulic lines 8 or 9, respectively, into the piston 19 or rod 21 cavity of the control cylinder 5, the rod 4 is extended or retracted, which, acting on the two-arm lever 3, changes the position of the cylindrical guides 1 with plow carriages 2 relative to the soil or roof layer. By changing the shape of the surface of the soil or the roof of the formation, the movement of the extraction unit is controlled in accordance with the hypsometry of the formation.

 When sliding the control cylinder 5, the working fluid under pressure through a constant hydraulic throttle 18 also enters the lower chamber 15 and acts on the end face 11 of the plunger 10, which, compressing the spring 14, moves up. In this case, the liquid from the upper 16 and intermediate 17 chambers through the channels 20 and 22 is displaced into the drain hydroline.

 When reducing the control cylinder 5, the working fluid under pressure through the channel 20 enters the upper chamber 16 and, acting on the end face 12, moves the plunger 10 down, which compresses the spring 13 with the end 11, pushes the fluid from the lower chamber 15 into the piston cavity 19. Since the volume of the intermediate If the chamber 17 increases, then through an additional channel 22 the liquid enters this chamber from the drain hydraulic line. After disconnecting the control cylinder 5 from the pressure and drain hydraulic lines of the hydraulic line 8 and 9, the piston 19 and the rod 21 of the cavity are locked with a hydraulic lock (not shown). In this case, the fluid pressure in the piston 19 and rod 21 cavities is redistributed taking into account the sign and direction of action of the static load acting on the rod 4, the values of the areas of these cavities. As a result, taking into account the values of the areas of the ends 11 and 12 of the plunger 10 and the stiffness of the springs 13 and 14, the plunger 10 will be installed in some intermediate position.

 During the impact of the plow carriage 2 on the section of the guide 1 in the places of relative rotation of the sections along the working face in accordance with the hypermetry of the soil or the roof of the formation, the adjacent sections of the guides tend to reduce the angle of relative rotation between them. This is now possible due to the movement of the two shoulders of the lever 3 and the rod 4 with the piston relative to the control cylinder 5 with the locked hydraulic lines 8 and 9.

 If, for example, the impact is directed so that the rod 4 should extend out of the cylinder, then the working fluid from the rod cavity 21 flows through the channel 20 into the upper chamber 16 and, acting on the end face 12 of the plunger 10, moves it down. In this case, the plunger 10 compresses the lower spring 13. The working fluid from the cavity 15 is displaced through a constant hydraulic throttle 18 into the piston cavity 19. When the impact is reduced, the plunger 10 under the action of the spring 13 begins to move upward, compressing the upper spring 14 and displacing the liquid from the upper chamber 16 to rod cavity 21. In this case, the working fluid from the piston cavity 19 through a constant hydraulic throttle 18 enters the lower chamber 15. The change in the volume of the working fluid in the intermediate chamber 17 is compensated by hydraulic communication it through an additional channel 22 directly with a drain hydroline.

 Similarly, the oscillating movement of the rod 4 with the piston occurs, if the initial impact is aimed at reducing the control cylinder 5.

 The oscillating movement of the rod 4 is accompanied by alternating flow of the working fluid through a constant hydraulic throttle 18 and along the channel 20. As a result of hydraulic losses, the increase in pressure decreases as a result of dissipation of fluid energy. This contributes to the friction of the piston and rod 4 on the cylinder of the control cylinder 5. As a result, the oscillations of the rod 4 damp and it returns to its original static position.

d $\genfrac{}{}{0ex}{}{\text{2}}{\text{1}}$ h₁=

(D²-d²)h (1)

D $\genfrac{}{}{0ex}{}{\text{2}}{\text{1}}$ h₁=

D²h , (2) где h и h₁ - перемещение соответственно штока 4 и плунжера 10 в процессе колебаний.The oscillatory movement of the rod 4 when the rod 21 and piston cavities 19 are locked can be ensured provided that the volumes of liquid displaced from these cavities are equal to the volume of liquid entering the upper 16 or lower 15 of the chamber, respectively. Assuming that the volumes of the springs 13 and 14 are equal, we obtain

d $\genfrac{}{}{0ex}{}{\text{2}}{\text{1}}$ h ₁ =

(D ² -d ² ) h (1)

D $\genfrac{}{}{0ex}{}{\text{2}}{\text{1}}$ h ₁ =

D ² h, (2) where h and h ₁ are the displacements of rod 4 and plunger 10, respectively, during oscillations.

/D . (3)
Зависимость (3) позволяет определить диаметр второго торца d₁ плунжера 10 при известных диаметрах поршня D и штока d гидроцилиндра управления 5 и принятом значении диаметра первого торца D₁ плунжера 10.After transformations of dependencies (1) and (2), we obtain
d ₁ = D

/ D. (3)
Dependence (3) allows to determine the diameter of the second end face d _{1 of the} plunger 10 with the known diameters of the piston D and rod d of the control cylinder 5 and the accepted diameter value of the first end face D _{1 of the} plunger 10.

 Thus, due to the fact that a spring-loaded plunger with ends of various diameters is placed in the cylindrical cavity of the rod of the control cylinder that is closed at the ends, the lower chamber of the plunger is hydraulically connected through the permanent throttle to the piston cavity of the control cylinder, and the upper chamber of the plunger is connected to the rod cavity of this hydraulic cylinder moreover, the diameters of the ends of the plunger, the diameters of the piston and rod cavities of the control hydraulic cylinder are interconnected by a certain dependence, ix reliability of the control device as a result of reduction of shock effects guide carriages executive excavation unit.

Claims (2)

 1. UNIT CONTROL UNIT BY PLASTIC HYPSOMETRY, including two two-arm levers, one of which is pivotally connected to the overlap, and the other to the conveyor bracket, one shoulder of each lever is rigidly connected to the guide body guide, and the other is fixed to the control cylinder rod, whose cylinder connected to pressure and discharge hydraulic lines, characterized in that, in order to increase the reliability of the device by reducing shock loads, each control cylinder is spring-loaded for both the ends of the plunger with a groove placed with the possibility of reciprocating movement along the axis of the rod of this hydraulic cylinder in a cylindrical cavity made inside the rod, closed at the ends, and the diameter of the lower end of the plunger is larger than the diameter of its upper end, while the ends of the plunger and its groove form with a closed cylindrical cavity of the lower, upper and intermediate chambers, the lower of which is hydraulically connected to the piston cavity of the hydraulic cylinder by means of a constant hydraulic throttle, the upper chamber is connected and channel means formed in the rod with the rod end of the hydraulic cylinder, and the intermediate chamber - formed in the stock by the supplemental channel to the return hydraulic line. 2. The device according to p. 1, characterized in that the diameter of the upper end of the plunger is determined by the formula
d ₁ = D

/ D,
where D ₁ and d ₁ are the diameters of the lower and upper ends of the plunger;
D and d are the diameters of the piston and rod of the control cylinder.

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