SU1180462A1 - Hydraulic drive of vibrated teeth of excavator bucket - Google Patents

Abstract

HYDRAULIC DRIVE OF VIBRATION TEETS OF THE EXCAVATORY BUCKET, including hydraulic pump with an engine, exciter cylinder, distribution control equipment and piping, characterized in that, in order to enhance operational capabilities, the hydraulic pump is designed as a pulsator, with a chassis housing, and a body enclosure with a housing enclosure, with a chrome-shaped housing enclosure, and a chrome-shaped housing enclosure, with a hatch, a housing housing, and a housing with a hatch, enclosing a control unit, and cameras and eccentrics, each of which is connected to the engine shaft with the possibility of constant interaction with the pistons and has a protrusion and corresponding to it on the opposite side, there is a cavity with equal central angles11 in the range of 20-180, while the piston chambers are connected to opposite cavities (L of the cylinder-vibration exciter, which is nondifferential. Fig. 4 Od

Description

The invention relates to mechanized soil excavation engineering, in particular to hydraulic drives of single-bucket excavators.

The purpose of the invention is to expand the operational capabilities of the excavator by increasing the maximum strength of the soil that can be developed.

Fig. 1 shows the hydraulic diagram of the drive of Fig. 2; a schematic diagram of the hydraulic pump; Fig. 3 is a diagram of the movements of the teeth; Fig. A is a diagram of the movements of the bucket and teeth relative to the soil; Fig. 3 is an example of how the teeth are inserted into the soil by graphic in a way.

The hydraulic drive consists of the engine 1, the hydraulic pump 2 of the pulsator type, the pipelines 3, the cylinder-vibration exciter 4 with the piston 5 and the rod 6, which is connected to the teeth 7 of the bucket 8 by means of t g 9. For possible. In order to preserve the pipeline pipelines, the actuator includes non-return valves 10. A safety valve 12 is connected to the pipelines through the check valves 11 to protect the components and drive units from overloading.

The hydraulic pump (figure 2) includes a housing 13 within which a shaft 14 is installed with an eccentric 15 having protrusions and cavities corresponding to them on the opposite side. Under the action of 16, two groups of diametrically located pistons 17c mounted in the housing are constantly in contact with the eccentric. The pistons of each group are located parallel to the axis of the eccentric (in Figure 2, their projections coincide), and their number is selected in accordance with the required pump capacity. The piston chambers are connected to the corresponding cavities of the vibration cylinder by means of pipelines. 3. The shape of the eccentric profile corresponds to the required law of movement of the vibrating teeth.

The hydraulic actuator works as follows.

The engine 1 causes the rotation of the pump shaft 2 (figure 1). At the same time, the pump pistons moving in the radial direction create pulsations of fluid pressure in the pipelines 3,

which are transmitted to the corresponding cavities of the vibration exciter cylinder 4, causing the piston 5 with the rod 6 and the teeth 7 connected with it to perform oscillatory movements.

The bucket can be made with all movable teeth or with a group of movable teeth.

The principle of the hydraulic pump can be represented as follows (figure 2). The pump shaft 14 rotates the eccentric 15, and the pistons 17 move in the openings of the housing 13, creating pressure pulsations in the pipes 3.

In order to ensure optimal conditions for the process of vibratory digging, the law of oscillation of the teeth of the bucket and, consequently, the profile of the pump's eccentric, must be chosen in such a way as to reduce the time the teeth enter the ground during the period of one cycle of their oscillations. For this, the eccentric is made with protrusions and with corresponding with them

cavities on the opposite side, with the central angles of the protrusions and valleys being chosen so as to ensure, on the one hand, the minimum time for teeth to penetrate into the ground, and

the other is smooth enough work

mechanism, without impacts between the mutually | eukindumi elements. Based on this, it is recommended to choose the central angles of the depressions and projections of the eccentric in the range of 20-180 °. Possible variants of the law of oscillations of the teeth relative to the bucket (fig.Z) with the same period of oscillation T:

1 - sinusoidal X 4Lsin (at; II - uniform reciprocating V ip (t), III - a special law with impulse rotate of the teeth X {j (fc), chosen on the basis of these requirements,

where X is the movement of the teeth relative to the bucket, t is the time; a is the oscillation amplitude of the teeth i 0) is the oscillation frequency, {«(i) and 1р (i) are the functions describing the indicated laws of oscillations.

From the graphs IV (Fig. 4) of the movement of the bucket relative to the ground (uniform movement at speed Y) and the movement of teeth relative to the ground, according to different laws I, II, III (Fig. 3), it is seen that during each oscillation the tooth crashes into the ground into some ground / , the value of & k, depending on the speed of movement of the bucket V and the oscillation period of the teeth T. The insertion time -Igp depends both on the magnitude of LH and on the form of the law of oscillations, and the pulsed law of oscillations provides for a shorter time L bwre compared with both a sinusoidal .tepi and a uniform law of motion t

Vrg (Fig.4).

Reducing the insertion time allows to reduce the pulling force on the bucket required for digging, which follows from the law of conservation of momentum of forces. Indeed, if we designate the average value of the traction force applied by the excavator's hand to the bucket, by means of the RTYU Y of the ground resistance to fracture acting on the tooth, through P, then according to the law of storing the impulse of forces during the oscillation period (not considering the strength of etc.)

.

It follows that the required thrust force decreases with decreasing penetration time.

Pt

time

t gvod the analytical dependence of igp on the parameters of the law of oscillation of the teeth and other factors is difficult.

therefore, it is possible to use a graphical method of finding tgp for specifically specified conditions.

As an example (figure 5) it is shown that igp is found for conditions of 2 m / s; T 0.03 s; A 0,006 m. In this case, the line V corresponds to the ex-. a dentric with a projection angle of 20, and a line VI - an eccentric with an angle

Spill 180 °.

For comparison, line VII is also shown, corresponding to the uniform motion of the vibrating toes, which is carried out in a known drive design. From the construction, 1: d., 0015, 0.005ci —bvd, 007 s.

Thus, the laws of oscillations provide a reduction in the time of incision tvp and, consequently, the required for digging pull force by 4.5 and 1.4 times, respectively.

The use of the proposed hydraulic drive allows reducing the pulling force required for digging, thereby facilitating the development of durable soils and expanding the operational capabilities of the excavator, since with the same structural and strength characteristics it becomes possible to develop soils of greater strength. In addition, the proposed drive is structurally simpler known, which also increases its technical and economic efficiency.

Fi. H. I (K-a Sin ait) 1 ((i}) § O.m Fig. 5 U05 time t, C

Claims (1)

HYDRAULIC DRIVE OF VIBRATION TOOTHS OF EXCAVATOR BUCKET, including a hydraulic pump with an engine, a vibration exciter cylinder, distribution and control equipment and pipelines, characterized in that, in order to expand operational capabilities, the hydraulic pump is made in the form of a pulsator containing a housing with two groups pistons with chambers and eccentrics, each of which is connected to the motor shaft with the possibility of constant interaction with the pistons and has a protrusion and corresponding to it against on the opposite side, a cavity with equal central angles within 20-180, while the piston chambers are associated with opposite cavities of the vibration exciter cylinder, which is non-differential. SU, „, 1180462