SU499021A1 - Inertia screw hydraulic press hammer - Google Patents

Description

one

The invention relates to press-forging equipment for metal forming and, in particular, to machines operating in a press-hammer mode with an approach stroke.

A screw hydraulic press hammer is known, comprising a bed with lifting cylinders, a slide moving in the bed guides, interacting with a hollow screw, inside of which there is a fixed plunger, and also a moving nut screwed with a screw.

The disadvantage of the well-known press hammer is that when braking the screw, the reactive braking moment is transmitted to the frame, and when the drive is switched to raising the slide, energy is lost to the braking of the screw rotation.

To eliminate these drawbacks in the proposed screw hydraulic press hammer, the movable nut is made with an external non-self-locking thread, in the same direction as the internal thread, but with a greater pitch, while the press hammer is provided with threaded rails attached to the slide frame and interacting with the external thread of the movable nut. In addition, the gap between the screw surfaces in the threaded engagement of the rails with the nut is larger than in the threaded engagement of the nut with the screw.

FIG. 1 shows the structural scheme of the proposed press hammer; in fig. 2 and 3 -

diagrams that explain the operation, respectively, of matching the threaded rod with the external thread of the nut (node I in Fig. 1) and the screw thread of the screw with the nut (node II in Fig. 1) during the approaching stroke or the acceleration of the slide downwards; in fig. 4 and 5 are diagrams of operation, respectively, of coupling the threaded rod to the external thread of the nut and the threaded interface of the screw with the nut during the action of the slide on the technological object.

An inertia screw hydraulic press hammer consists of a bed 1 in which lifting cylinders 2 with plungers 3 are fixed. In the guides of the bed 1, a slider 4 is freely fitted, resting its lower part on the plungers 3, and supporting hollow screw 5 with a non-braking thread with its upper part.

On the slider 4 there are fastened threaded rails 6, which are attached to the external non-self-braking nut 7 and freely seated in the guide grooves of the bed 1. The threaded rails 6 are made with a concave toothed surface in the form of nut thread segments. The nut 7 is mounted in the frame 1 on the support plates, so that it can rotate around its axis and is fixed against axial and radial movements. The gap 5п between the screw mating surfaces of the external thread of the nut 7 with the rails 6 is made larger (see Fig. 2) than the similar gap SB in conjunction with the thread of the screw 5 with the nut 7 (see Fig. 3). () In the upper part of the screw 5, a plunger 8 with an axial channel is mounted in the seal, fixed in the upper cross bar of the bed 1. The external thread pitch of the nut 7 is larger than the screw pitch of the screw 5, according to the following dependency: Y, AGG / /, where: / g; / in - the moment of inertia, respectively, of the nut 7 and screw 5; p in - step, respectively, of the external thread of the nut 7 and the thread of the screw 5; Mg; it is time to stop the turning of the nut 7 and screw 5 during the deceleration of the slide 4, respectively. The external and internal threads of the nut 7 are made in the same direction (both left or both right). The inertial screw driver hydraulic press hammer works in the following manner. In the initial state, the fluid line E is supplied with pressurized fluid, and the highway F is connected to the drain. Therefore, the slider 4 and the screw 5 are in the highest position. To strike a forging, for example, the E line is connected to the drain, and the F line - to a filling battery (low pressure), refill us; the screw cavity 5 with liquid when the latter, under its own weight and low pressure of the filling battery moving down at the same time, spinning clockwise when viewed from above (we assume that the thread is right). After lowering the slider 4 for a certain distance, depending on the required energy of the stroke, line F is connected to the high-pressure battery. This leads to intensive acceleration of moving parts, before impacting on the technological object. During the approach and acceleration stroke, the threaded rails 6, by selecting the gap Sn at the beginning of the stroke downward, under the action of the force generated by the fixed plunger 8 and transmitted through the screw 5 to the slider 4, unscrew the nut 7 in the direction opposite to the rotation of the screw 5. In FIG. 2 shows the force decomposition - RV (two slats) of the screw 5 on the slider 4, which results in the unwinding force Pr, which causes the nut 7 to rotate with the angular velocity Wz and the acceleration Er-Rail 6 at that time moves behind the slider 4 in the direction of velocity V with acceleration and translational movements. Screw 5, also moving downward with speed V and acceleration and relatively rotating in the opposite direction of the nut 7, acts on the lower screw surface of its thread and on the upper screw surface of the nut thread 7 and obtains angular acceleration E in the direction of the angular velocity WB. This happens due to the fact that the thread pitch of the screw 5 is less than the pitch of the external thread of the nut 7. The force of the PTS, with which the screw 5 acts on the nut 7, folding (as shown in Fig. 3 in cross section b) creates a force Pp.t . acceleration of the nut 7 and force Rr.v acceleration (unwinding) of the screw 5 (forces Rr.g. and Yar.v are equal in absolute value). The functions of the laths 6 are thus reduced to the implementation of a rigid kinematic connection of the rotation of the screw 5 and the nut 7 and bringing this rotation in line with the previously mentioned relation determining the equality of the rotational energies of the nut 7 and the screw 5 at any moment of movement of the slide 4. At the moment of contact of the slider 4 with the forging, the technological resistance force Pf slows down the translational movement of the slider 4 and screw 5, the latter, rotating by inertia towards the rotation of the nut 7, begins to act the upper screw surface of its cut The threads on the lower screw surface of the internal thread of the nut 7. At this time, due to the fact that the gap 5p between the turns of the external thread of the nut 7 and the teeth of the rail 6 more than the same gap 5c in the threaded interface of the screw 5 with the nut 7, the rail 6 does not perceive the force from the external thread of the nut 7. The RT technological resistance force closes through the slide 4, the screw 5, the nut 7 and the frame 1. The RT technological resistance force transferred from the screw 5 to the nut 7, unfolds and creates a force R., inhibiting the screw 5, and force RT.G, braking rotational hectare 7 and ki modulo equal force RT.VTakim way screw 5, while rotating in the same direction, receives angular deceleration and moving the camping in the same direction, - and the progressive deceleration. The nut 7 also rotates in the previous direction Wz and receives an angular deceleration EG, trying to push down the screw 5 which is unscrewing from it by inertia, and thus doing the work of deforming the forging. Since the energy of the translational motion of the slider 4 and the screw 5 is consumed, and the energy of the rotational motion of the nut 7 is equal to the energy of the rotational motion of the screw 5, having consumed it to deform the locks, it does not simultaneously stop braking the other. Consequently, the bed at the end of the working ode takes the tensile load, the inertial moments of braking of the screw 5 of the nut 7 are mutually balanced.

five

To return the press hammer to its original state, it is necessary to unload the G-line to the drain, and to the E-line to iodine the liquid from the high-pressure accumulator or pump. With this, the slider 4 and the screw 5, under the action of the plungers 3, are raised to the extreme upper position.

Form m l l a iso b re e and u

An inertia hydraulic screw press hammer containing a frame with lifting cylinders, a slide that moves in the bed guides and interacts with a hollow screw with a fixed plunger and a screw nut screwed into the screw.

6

characterized in that, in order to increase the energy intensity and unload the bed from the torques, the movable nut of the hammer is made with an external non-self-braking thread of the same direction with an internal thread, but with a large pitch, this press hammer is saben free located in the guides beds with threaded slats, fastened with a slide and interacting with an external thread of a movable nut.

2. Press hammer on and. 1, characterized in that the gap between the viit surfaces in the threaded coupling of the rails with the nut is large, cpl in the threaded coupling of the screw nut.

f

FIG. /