SU1204989A1 - Bed for testing hydraulically operated hoist of dump trucks - Google Patents

Description

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This invention relates to a transport engineering industry and can be used to test dump lifts.

The purpose of the invention is to reduce the test conditions to real and reduce the labor intensity of the tests.

The drawing shows the pial scheme of the proposed stand.

The stand consists of a hydraulic load, in case 1 of which a piston 2 with a rod 3 is placed, a program mechanism that includes a boom containing a rod 4 attached to the rod 3 of the load loader, a stop 5 m with mounting screws 6, a bar 7, d {) ( .1isseling device, containing bss; body 8 with roller 9, rod 10, coius surface 11 interacting with saddle 12 of body 8, barrel hole 13, sleeve 14 with roller 15, pressure tube, cavity 16, pumping cavity 17 and cavity 18 plum, slider 19 with inclined surface, hinge 21 removed from the rod 22 and the piston 23 about a cylinder 24, three-way distributor, containing a sorpus 25 with annular borings 26-28 and holes 29 and 30, a spring 31 and a spool 32, a hydrographic drive and a spool actuator comprising a housing 33, a piston 34, a rod 35 , pru-; -kinu 36, thrust washer 37, adjusting nut 38.

The working cavity 39 of the loading device is connected via a non-return valve 40 to the pump accumulator 41 and directly to the pumping cavity 17 of the throttling device and the cylinder cavity 42. The cavity 43 of the slip of the load is connected to the oil tank. An annular boring 27 of the housing 25 of the three-position distributor is connected to the pump 44 and, through the two-position distributor 45, to the oil tank. The openings 29 and 30 of the three-position distributor are connected respectively to cavities 46 and 47 of the control cylinder 24. The drainage cavity 18 of the throttling device communicates with the hydraulic accumulator 41. The maximum pressure of the pump 44 is limited by the safety valve 48. The test hydraulic lift 49 is attached to the body to the support 50, a sliding link of a smaller diameter 51 to the guide 52, on the axis 53 which is mounted a roller 54, connected by a tro10

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catfish 55 with rollers 56 and 57, mounted on the axis 5B of the rod 3 of the load. The hydraulic system of the test hydraulic lifter contains on all 5 soy 59, check valve 60, adjustable throttle 61, safety valve 62 and two-way valve 63. Electromagnets 64 and 65 of the two-way valve 45 and 63 are controlled by electric switches 66 - 68. Electric devices 67 and 68 are turned on a stop 69, an electromagnet 65, a stop 5 "The stem 35 of the hydraulic cylinder is connected to be adjustable m along the length of the flexible element 70 with the spool 32.

The stand is operated as follows.

The pumps 44 and 59 are activated. The electromagnet 65 is turned off, the on-off valve 63 is closed, the electromagnet 64 is turned on, the on-off valve 45 is open. The working fluid from the pump 44 through the open two-position valve 45 enters the oil tank, while filling it with the discharge pressure of the cavity -.46 and 47 of the control cylinder 24. The slider 19 does not move. The working fluid from the pump 59 through the adjustable throttle 61 enters the oil tank, filling the test hydraulic lift. When the adjustable throttle 61 overlaps, the links of the sprayed hydraulic lift 49 are advanced, starting with the position shown in FIG. 1, moving the guide 52 to the left with the roller 54. The cable 55 on both sides of the roller 54 is tensioned, acting through the rollers 56 and 57, the axis 58 on the rod 3 and the piston 2 of the load body. The rod 3 with the piston 2 is moved to the left, the working fluid is displaced from the cavity 39. The check valve 40 is closed. Under the action of pressure in the cavity I7 of injection of a throttling device. the rod 10 is turned upward, compressing the spring 13. Between the conical surface 11 and the seat 12, a gap is formed, through which the working fluid is forced into the drain cavity 18 and further into the hydroaccumulator 4.

55 Q by increasing the stroke of the tested hydraulic lifter 49, the roller 15 rolls along the inclined bar 7, and the sleeve 14 moves upwards, reducing

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the force of compression of the spring 13, and, therefore, the pressure in the working cavity 39 of the load. The cavity 43 is drained by a vacuum when filled with a working fluid from a small tank. When the hydraulic lifter reaches the extreme left position, the stop 69 presses the electric switch 68, which turns on the electromagnet 65, which opens the two-position valve 63. The pressure in the working cavity 39 of the loading device drops. At the same time, pressure drops in the cylinder 42 of the actuator of the spool 32. Under the action of the spring 36, the piston 34 with the rod 35 moves to the right, weakening the tension of the flexible element 70. The zolonik 32 moves to the right under the action of the spring 31. The pump 44 through an annular bore 27, an opening 29 communicates with the cavity 46 of the control cylinder 24. The cavity 47 of the control cylinder 24 through the opening 30 and the annular boring 28 is connected with the drain, as well as the annular boring. Due to the fact that the pressure of the pump 44 with the open two-position distributor 45 is almost equal to the pressure of the drain, the movement of the piston 2 with the rod 22 and the slide 19 does not occur.

Under the action of pressure in the hydroaccumulator, the check valve 40 opens, and the pressurized fluid enters the working cavity 39 of the preheater. The piston 2 with the rod 3 moves to the right, the rod 3 through the axis 5 rollers 56 and 57, the cable 55, the roller 54, the guide 52 acts on the pull-out link of a smaller diameter 51. The pull-out links move to the right in the sequence from the smallest to the largest. The working fluid from the pump 59 and from the cavity of the tested hydraulic lift through the two-position valve 63 enters the oil tank. At the beginning of the movement of the moving link of larger diameter when compressing the tested hydraulic ram, the emphasis 5 acts on the electric switch 66, which makes an idle stroke counterclockwise. In the extreme right position, the stop 69 presses the electric switch 67, which turns off the electromagnets 64 and 65. The two-way valves 45 and 63 are closed. Link test hydro

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the lift begins to advance in sequence from larger to smaller. The guide 2 with the roller 54 moves to the left. The cable on both sides of the roller 54 is tensioned, acting through the rollers 56 and 57, the axis 58 on the rod 3 and the piston 2 of the loader. The rod 3 with the piston 2 moves to the left, displacing the working fluid from the cavity 39 through the injection cavity 17 and the discharge cavity 18 of the throttling device into the hydraulic accumulator 41. The check valve 40 is closed. At the moment when the on-off valve 45 is closed, pressure is generated in the cavity 46 of the control cylinder and the piston 23 with the rod 22 moves the slider 19 to the right. The roller 9, rolling over the inclined surface 20, compresses the spring 13. The pressure in the pressure chamber 17 of the throttling device and the cavity 42 of the spool actuator hydraulic cylinder increases.

When the required pressure is reached, which is set by adjusting the length of the flexible element 70, the piston 34 with the rod 35 moves to the left, compressing the spring 36. Actually, i; By twisting the flexible element 70, the spool 32, compressing the spring 31, moves to the left. The cavity 46 of the control cylinder 24 through the opening 29 and the bore 26 is connected to the drain. The movement of the piston 23 with the rod 22 and the slider 19 to the right stops. If the pressure in the working cavity 39 of the load exceeds the specified, the piston 34 with the rod 35, compressing the spring-. well 36, moves the spool 32 from the neutral position to the left. The cavity 47 through the hole 30 and the annular bore 27 communicates with the pump 44. Under pressure in the cavity 47 of the control cylinder 24, the piston 23 with the rod 22 moves the slider 19 to the left. The spring 13 of the throttling device expands to the required value, and the pressure in the working cavity 39 of the load device, in the cavity 17 of the injection of the throttling device and in the cavity 42 of the hydraulic cylinder of the drive of the slide valve is reduced to a predetermined value. The piston 34 with the rod 35 5 is moved to the right by the action of the spring 36; under the action of the spring 31, the valve 32 returns to the neutral position. Thus auto0

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pressure is magically maintained and the working cavity 39 is loaded when the linkage of the larger diameter of the test hydraulic lifter is extended. Platform lifting at small angles is simulated when the load on the hydraulic lift is almost unchanged. At the end of the travel of the larger-diameter link, stop 5, acting on the electric switch 66, turns on the electromagnet 64. The two-position valve 45 opens and the pump 44 communicates with the oil tank. Reducing the pressure in the working cavity 39 and the load handler and, consequently, the load on the test hydraulic lift during the work flow is achieved by reducing the compressive force of the spring 13 by rolling the roller 15

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throttling device on the sloped bar 7 copier. When the lifter under test reaches the leftmost position, the stop 69 5 presses the electroswitch 68 and the process repeats. The magnitude of the load on the larger link of the hydraulic lifter under test is set by adjusting the length of the flexible element 70,

to a variable nature of the load in the process of the entire stroke - tilt slats 7 copier adjustment screws b. The use of rollers 54,56957 and cable 55 for connecting

15 of the tested hydraulic lifter with a loader reduces the working stroke of the load by almost two times compared with the working stroke of the hydraulic lifter.

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Editor S.Lysina

Compiled by N.Ve lko Techred 3.Paly

Order 8518/43 Circulation 896 Subscription

VNIRSHI State Committee of the USSR

for inventions and discoveries 1Т3035, Moscow, Ж-35, Raushsk nab., 4/5

Branch ShSh Patent, Uzhgorod, 4 Project St.

Proofreader L.T. sko

Claims (1)

STAND FOR TESTING HYDRAULIC LIFTS OF THE DUMP, containing a loader connected to the hydraulic control system in the form of a hydraulic cylinder fixed on the base of the test bench and communicated by a rodless cavity through a check valve with a hydraulic accumulator and a power supply system for the tested hydraulic lift, characterized in that, in order to reduce the conditions and reduce the conditions the complexity of the tests, the hydraulic control system of the loader is equipped with a built-in hydraulic line that communicates the rodless cavity of the loader with a hydraulic accumulator mupator, parallel to the non-return valve, a throttling device, including a housing with a saddle mounted on the base of the stand by means of guides, a rod located in it; made with a conical surface at the end for interaction with the seat of the housing and spring-loaded relative to the sleeve installed in the housing with the possibility of longitudinal movement, and rollers mounted on the housing and the sleeve, placed on the base of the stand control hydraulic cylinder, the rod of which is pivotally connected to a slide located on the supporting surface of the base and made with an inclined surface for interacting with a roller mounted on the body of the throttling device, and a three-position four-line a distributor, and two lines of which are connected respectively to the cavities of the control hydraulic cylinder, and two others with a pump and with a drain, the distributor is controlled by a hydraulic cylinder communicated by the rod-cavity. C with a rodless cavity of the loader, a rod is attached to the rod of the loader, bearing the blocks fixed to the axis and the bar mounted with the possibility of changing the angle of inclination for interacting with the roller mounted on the sleeve of the throttling device, and on the base of the stand in the guides there is a support with a block for connecting to it a pull-out link of the smallest diameter of the tested hydraulic cylinder, and a cable is stored through all the blocks. · Q