SU985484A1 - Hydraulic cylinder with hydromechanical lock - Google Patents

Description

(54) HYDROCYLINDER WITH HYDROMECHANICAL LOCK

The invention relates to machine construction and can be used in hydraulic cylinders to ensure rigid fixation of the piston relative to the cylinder.

A hydraulic cylinder with a hydromechanical lock is known, comprising a housing, a hollow piston with a rod, mounted in the housing to form piston and rod stocks, a lock having locking elements, and a plunger for driving the locking elements, placed in the piston cavity and spring-loaded relative to it 13.

A disadvantage of the known device is the low speed of the lock in the case of installation in the piston cavity of a throttle regulating device, loading of the locking elements, and as a result, the destruction of the inner surface of the cylinder from contact with the locking elements when moving.

The purpose of the invention is to increase the speed of the lock while protecting the inner surface of the cylinder from contact with the loaded fixing elements.

This goal is achieved in that the lock plunger is provided with an additional piston rigidly connected with it, installed in the stem cavity, and the cavity between them communicates with the rod of the hydraulic cylinder.

Figure 1 shows the hydraulic cylinder with hydromechanical lock; on fig.2skhema acting on the elements of the castle

10 effort.

The hydromechanical lock contains a housing 1 inside which there is a hollow main piston 2 with a rod 3, section 10 11th cavity of the cylinder on

15 piston and rod end cavities 4 and 5, respectively.

Inside the piston 2, on the side of the piston cavity of the housing 1, a plunger 6 is installed, which is under the pressure of the compressed spring 7 and is rigidly connected by means of a stud 8 with an additional piston 9. The latter is installed in the cylindrical bore of the piston 2 coaxially with the plunger 5. Additional bores 10 are made connecting the rod cavity 5 of the housing 1 with the cavity 11 of the main nopuHiH 2 located between the additional piston 9 and the plunger 6.

Claims (1)

30 The locking groove 12 is made on the inner surface of the cylinder, and locking balls 14 are located in the radial holes 13 of the piston 2, interacting with the annular recess 15 at the end of the plunger 6. The device works in the following way. In the initial state, the piston 2a is fixed and is in the extreme left (Fig. Position, while the balls 14 are inserted into the locking knob 12 of the housing 1 and fixed in it by the plunger b, which is in the leftmost position, defined by the additional stop piston 9 into piston collar. To remove piston 2 from the lock, the pa Qo fluid is supplied to piston cavity 4, and the rod cavity 5 is connected to the drain through a throttle device. Piston 2 keeps c from moving until plunger. 6 do not move ts to the right, freeing the balls 14. A mechanical lock opens. When the piston moves to the right (Fig. 1), the plunger 6 is on: it is in the right position KpafyieM, when the condition P, N is fulfilled (11 F-DRR L F ,, / 5 F Р .- (в5-а) -, F: / f Wd); E |, - pressure in the piston strip; P "P - spring force; N - external load value. Expression. L 1) is obtained from the following equations: a) - condition of equilibrium of the piston; b) P Fj / BjflRj + Pnp condition of the plunger position in the extreme right position. From equation (a), we have iV where Pn is the pressure in the rod end. Substituting the resulting expression for equation (b), we obtain the expression (in which the inner surface of the cylinder is protected by the movement of the piston 2 from contact with the balls loaded with a spring and yes: the cylinder cavity. When installing the spindle 2 on the mechanical lock, the spring-loaded plunger 6 acts with its annular recess 15 on the balls 14 resting on the inner surface of the cylinder. To install the piston on the mechanical lock, the working fluid is supplied into the rod 5 and simultaneously through the holes 10 into the cavity 11. The piston cavity 4 communicates with the drain through the throttle device. When the piston moves to the left, the plunger 6 is in the extreme right position if condition (1) is fulfilled, while the force from the spring 7 and from the pressure of the working fluid in the rod cavity 5 to the plunger b is not transmitted through the balls to the inner surface of the cylinder. When the piston 2 reaches the left extreme position, the pressure in the rod cavity 5, acting together with the spring 7 on the plunger 6, moves it to the left, This plunger b pushes the locking balls 14 into the locking groove 12. A mechanical lock closes. The force on the plunger b from the pressure in the rod end of the cylinder significantly exceeds the force on it from the spring 7. It is decisive for the speed of movement of the plunger when installing the piston 2 on the lock, which also reaches a significant value. The closure time of the mechanical lock in this case is significantly reduced compared with the known devices. In addition, since the proposed pressure in the piston cavity when closing the lock reaches a significant value, the degree of intrusion of the filter in the drain line of the hydraulic system does not affect the performance of the mechanical lock. The invention has a hydraulic cylinder with a hydromechanical lock, comprising a housing, a nojMe piston with a rod, mounted in the housing to form piston and rod cavities, a lock, fittings, fixing elements, and a plunger for driving the fixing elements, located in the piston cavity and spring-loaded relative to it, differing from that, in order to increase the speed of work, the lock plunger is equipped with an additional piston rigidly connected with it, installed in the stem cavity, and the cavity between them communicates with the rod cavity v g Idrotsilindra. Sources of information taken into account in the examination, 1; USSR author's certificate 214999, cl. F 15 B 15/26, 1967.