RU2841002C1 - Mining excavator bucket cutting assembly - Google Patents

Abstract

FIELD: soil-shifting.

SUBSTANCE: invention relates to excavating equipment, namely to single-bucket excavators, and can be used in construction of a bucket of a mining excavator. Cutting assembly of a bucket of a mining excavator contains teeth fixed on a front wall of the bucket. Teeth have wedge-shaped working part formed by convex upper and concave lower curvilinear faces. Angle between axis of teeth seat and axis of handle beam in vertical plane is constant during excavation and ranges from 120° up to 124°. Angle between axis of tooth seat and bisector of angle of wedge-shaped part of tooth in vertical plane ranges from 16° up to 23°. Teeth cutting edge length varies from 600 to 750 mm. Also, axis of teeth seat can be parallel to plane of front wall of bucket.

EFFECT: increasing the productivity of the excavator, as well as increasing the period between repairs.

2 cl, 5 dwg

Description

Field of technology

The invention relates to earthmoving equipment, namely to single-bucket excavators, and can be used in the design of a quarry excavator bucket.

State of the art

The bucket is the most important part of the excavator's working equipment, the performance of which determines the machine's operating indicators. The bucket directly interacts with the soil and is subject to enormous abrasive and impact loads.

Buckets are classified by the type of their connection to the machine handle. It can be hinged or rigid. For many quarry excavators, a rigid connection of the bucket to the handle is used, which is the most repairable in quarry conditions.

Further in the text, the mention of the ladle implies precisely this rigid connection with the handle.

A bucket for a quarry hydraulic excavator is known, comprising a welded rear wall, a front wall with teeth and two side walls, the side walls are made of one piece of high-viscosity alloy steel, the front wall is made of one piece of high-manganese austenitic steel with projections on the cutting edge, between which teeth are fixed, on the inner and outer surfaces of the front wall there are arc-shaped knurlings with a radius of curvature of 25 mm, the welded joints of the front and side walls at the cutting edge are covered with linings made of high-manganese austenitic steel (see RU 107 192 (U1).

The presence of pads makes the bucket structure heavier, which negatively affects the performance of the excavator.

The design of the known bucket is excessively complex, given that the most susceptible to wear are the bucket teeth, which wear out completely on hard rocks in 5-10 days, and the characteristics of their wear largely determine the productivity of the work.

During operation of an excavator with a known bucket, the edges and cutting edge of the teeth are intensively abraded against rock or soil, as a result of which the teeth stop self-sharpening and their working element acquires a rounded shape. Operation of an excavator with such bucket teeth leads to an increase in pressure forces when cutting into soil and rock, the bucket filling factor and, accordingly, the loading speed decrease, which in turn leads to a decrease in productivity. In this case, difficulties in operation begin already when the working part of the tooth is still intact and there is still a significant distance from its edge to the edge of the front wall. If worn (rounded) teeth are not replaced, then further operation of the excavator, the bucket of which contains teeth that are not capable of destroying rock, can lead to premature wear of its components due to increasing vibration of the machine, excavator breakdown, and the creation of emergency situations.

Replacing teeth takes time, during which the excavator is idle, which further reduces the excavator's productivity.

An excavator bucket tooth is known, characterized by a wedge-shaped working part formed by a convex front and concave rear curved surfaces and made with a cutting edge offset downwards relative to the longitudinal axis of the tooth (see, for example, Author's Certificate of the USSR. 192081, RU 118 325 U1, RU 2107779 C1, RU 2 184 814 C1).

The curved wedge-shaped shape of the working part of the tooth improves the ability of the tooth to penetrate into the soil.

However, the nature of the wear of the bucket tooth depends significantly on the angle of interaction of the teeth with the plane of the selected rock. In addition to its shape, other factors also influence the nature of tooth wear: the spatial orientation of the front wall of the bucket, the specific design of the connection of the bucket with the handle, as well as the design features of the tooth itself. The same shape of the working part of the tooth with different other factors does not lead to the required high productivity and wear resistance of the teeth.

A known tooth in a bucket that does not provide an optimal angle of penetration into the rock from the point of view of tooth wear becomes inoperative already at partial abrasion, at a considerable distance from the edge of the front wall, and in such a state, its operation begins to cause significant difficulties. If the teeth are not replaced, then further operation of the excavator, in the composition of the bucket of which there are teeth that are not capable of destroying rock, can lead to its breakdown, premature wear of its components due to increasing vibration of the machine, to the creation of emergency situations.

An excavator bucket tooth is known, having a working section with upper and lower working surfaces and a shank, characterized in that the longitudinal axis of the working section of the tooth is inclined downwards and intersects the longitudinal axis of the shank, and the angle 9 between the said longitudinal axes is 3-12° (see RU 2 167 980 C1).

The known tooth is characterized by the presence of a downward slope of the working part, which contributes to the self-deepening of the tooth into the ground. However, as in the previous cases, the angle of inclination of the working part of the tooth is declared relative to the axis of the shank, coinciding with the plane of the front wall of the bucket, if the tooth is installed on the edge of its front wall. In this case, there is no binding to the tangent to the trajectory of the bucket movement. The trajectory of the bucket and its front wall, in particular, is close to a circle and the effect of self-deepening of the bucket is determined by the angle of deviation of the working part of the teeth from the tangent to this circle.

As a result, for some type of bucket, the stated angles may fall within the range of optimal angles of interaction of the tooth with the rock, ensuring self-deepening. For other buckets, fixed on the handle at other angles or having a different slope of the front wall, optimal interaction is excluded.

The lack of an optimal angle of interaction between the working section of the teeth and the soil eliminates the effective penetration of the teeth into the rock and the effective filling of the bucket.

The tooth parameters themselves may be important for increasing the digging efficiency, but this value is not decisive and can be disavowed by the presence of other parameters of the working element.

The closest in technical essence is an excavator bucket, which includes the front part of the bucket, where in the middle plane, which is perpendicular to the upper wall and the lower bottom, the front bucket part forms an external angle with the lower bottom exceeding 187.5 degrees (see RU 2 826 071 C2).

The authors of the well-known solution claim that there is an 11° rotation of the crowns or teeth, which ensures better soil extraction performance and protects the skid from wear.

The spatial orientation of the bucket teeth determines the angle of their penetration into the plane of the selected rock, and certain angles do indeed contribute to increasing the productivity of the excavator.

However, the cutting part of the known bucket is shifted relative to the longitudinal axis of the tooth upwards - inwards, which leads to wear of the lower curvilinear edge of the working part and the lower ribs.

Such tooth wear leads to a decrease in productivity long before the tooth wears out along the entire length of its working part. Thus, problems with productivity begin when there is still a significant distance from the edge of the tooth to the edge of the front wall, i.e. the working part of the tooth is still intact, and the appearance of these problems requires replacement of the teeth.

The known device does not provide the required high productivity, and its use leads to accelerated wear of the tooth edges.

In addition, in the known bucket, the angle of the front part of the bucket to the bottom plane is fixed, but the bottom plane is not fixed and is not tied to the levers that provide pressure forces. Changing the type of fastening of the bucket to the excavator handle or changing the angle of the rear wall of the bucket, with a constant external angle between the front part of the bucket and the bottom plane, leads to a change in the spatial orientation of the bucket relative to the handle, which leads to a change in the angle of interaction of the teeth with the rock when the bucket teeth cut into the ground, and therefore to its deviation from the optimal value, which, in turn, leads to a decrease in the productivity of the known device.

Revealing the essence

The technical result is an increase in the productivity of the excavator, as well as an increase in the duration of the period between repairs.

The specified result is achieved by the fact that in the cutting unit of the quarry excavator bucket, containing teeth fixed to the front wall of the bucket, having a wedge-shaped working part formed by a convex upper and concave lower curvilinear edges, the angle between the plane of the seat of the teeth and the axis of the handle beam in the vertical plane is from 120° to 124°, while the angle between the plane of the seat of the tooth and the bisector of the angle of the wedge-shaped part of the tooth in the vertical plane is from 16° to 23°, and the length of the cutting edge of the teeth is from 600 to 750 mm.

In addition, the plane of the teeth seat is parallel to the plane of the front wall of the bucket.

Implementation of the invention

The cutting unit of the quarry excavator bucket is explained with the help of drawings, where Fig. 1 shows the cutting unit of the quarry excavator bucket as part of the bucket, fixed on the handle of the quarry excavator, Fig. 2 - the excavator bucket, side view, Fig. 3 - the tooth of the cutting unit of the quarry excavator bucket and its position relative to the plane of the seat, side view, Fig. 4 - the bucket, front view, Fig. 5 - the tooth installed in the seat on the front wall of the bucket.

The following designations are made on the drawing:

1 - bucket, 2 - handle, 3 - handle axis (handle beam), 4 - front wall of the bucket, 5 - rear wall of the bucket, 6 - bucket bottom, 7 - boom, 8 - rocker, 9 - undercarriage, 10 - hinges, 11 bolt, 12 heel, 13 insert, 14 teeth, 15 - cutting edge (jaw), 16 length of the cutting edge of the teeth, 17 - wedge-shaped part of the tooth, 18 - bisector of the angle of the wedge-shaped part of the tooth, 19 - tail part (shank) of the tooth, 20 - axis (plane) of the tooth seat, 21 and 22 - upper convex and lower concave edges of the tooth, respectively, 23 - angle between the axis of the seat and the bisector angle of the wedge-shaped part of the tooth, 24 - angle between the axis of the tooth seat and the axis of the handle, 25 - flange connection, 26 - produced rock, 27 - edge of the front wall of the bucket.

The cutting unit of the quarry excavator bucket is a structure for fastening teeth of a certain wedge-shaped shape on the front wall of the quarry excavator bucket, and includes teeth with a wedge-shaped working part and a cutting edge length of the teeth from 600 to 750 mm fixed to the front wall of the bucket. The seat for the teeth is made on the front wall of the bucket with a vertical inclination relative to the plane perpendicular to the axis of the handle, namely: the angle between the axis of the seat of the teeth and the axis of the handle beam in the vertical plane is from 120° to 124°. In this case, the shape of the tooth is such that the tip of its wedge-shaped working part is deflected from the axis of its seat outward, so that the angle between the plane of the seat of the tooth and the bisector of the angle of the wedge-shaped part of the tooth is from 16° to 23°.

The axes of the tooth seating positions lie in the corresponding planes of the tooth seating positions, parallel to the plane of the front wall of the bucket.

The wedge-shaped curved working part of the tooth is formed by the convex upper and concave lower curved edges of the tooth.

The tooth is installed on the upper edge of the front wall of the bucket and is held in the seat on the front wall of the bucket by its tail section with support surfaces. The tooth is fixed in its seat by means of brackets or pins.

In a preferred particular case of execution, the seat of the teeth is made directly on the front wall of the bucket and the plane of the front wall, in this case, is parallel or even coincides with the plane of the seat of the teeth. In other particular cases of execution, the shape of the front wall may differ from flat and be curved.

The quarry excavator bucket, in addition to the front wall with teeth fixed to it, has a rear and side walls, as well as a bottom. The bottom can be equipped with an unloading mechanism.

The outer side of the rear wall is equipped with elements for rigid fastening to the handle beam.

The front, side and rear walls of the quarry excavator bucket are rigidly connected to each other, ensuring the possibility of maintaining a constant angle between the axis of the teeth seat and the axis of the handle.

The cutting unit of the quarry excavator bucket operates as follows.

Under the action of the excavator drive and transmission mechanism, the cutting unit of the quarry excavator bucket goes deep into the rock mass or soil and takes the impact of the rock on the teeth. The rock being destroyed moves along the upper edge of the tooth, falling into the excavator bucket.

The movement of the cutting unit during digging, when the bucket is raised to collect soil, occurs along an arc, which is part of a circle with a radius corresponding to the distance of the bucket from the axis of rotation of the handle. The handle beam during digging is always oriented perpendicular to the tangent to the trajectory of the bucket movement during soil collection.

Fixing the angle of the tooth seat axis to the handle axis in the vertical plane ensures the constancy of the angle of interaction of the working part of the teeth with the soil throughout the entire upward movement of the bucket during digging. Angles from 120° to 124° between the plane of the tooth seat and the axis of the handle beam in the vertical plane together with angles from 16° to 23° between the plane of the tooth seat and the bisector of the angle of the wedge-shaped part in the vertical plane correspond to angles that ensure self-deepening of the teeth into the soil when lifting the bucket, and the length of the cutting edge of the teeth from 600 to 750 mm allows for this deepening to be carried out effectively.

The constancy of the angles is maintained regardless of the design of the bucket and the type of its attachment to the handle, since the angles are tied to the tangent to the arc of movement, or more precisely, are measured from the perpendicular to the tangent to the trajectory of the bucket movement, i.e. from the axis of the handle, rotating in a vertical plane on its axis of rotation.

The upper and lower edges, as well as the cutting edge, are intensively abraded against rock or soil. In this case, the wear of the working part occurs mainly on the cutting edge side and the shape of the working part remains acceptable for work so that the abrasion of the teeth does not lead to the loss of their functionality. The teeth remain operational, i.e. do not require replacement, until the working part of the tooth is subjected to abrasion along the entire length of the cutting edge, right up to the upper edge of its seat.

When making the angle between the axis of the handle beam and the plane of the seat for the teeth within the range from 120° to 124°, together with the use of teeth with a wedge-shaped working part with a cutting edge length of the teeth from 600 to 750 mm, and teeth deflected in the vertical plane from the plane of the seat so that the angle between the plane of the seat and the bisector of the angle of the wedge-shaped part is from 16° to 23°, the pressure forces are reduced when the tooth is introduced into the rock, and the teeth are capable of finishing while remaining sufficiently sharp until they are worn almost to the edge of the seat of the front wall, without losing their operability.

The cutting unit of the quarry excavator bucket is an integral part of the bucket, however, its angular parameters are not tied to the spatial orientation of the bucket, but are measured from the axis of the handle, which made it possible to consider the cutting unit of the bucket as a universal independent element that can be used with quarry excavator buckets of different volumes and designs.

The use of a cutting unit of a quarry excavator bucket at mining enterprises has shown an increase in productivity and the duration of the teeth’s operation with unchanged ore parameters and blasting technology.

The parameters of the cutting unit of the quarry excavator bucket, namely: the angle between the plane of the tooth seat and the axis of the handle beam, the angle between the plane of the tooth seat and the bisector of the angle of the wedge-shaped part of the tooth, as well as the length of the cutting edge of the teeth were determined experimentally and improved in production conditions. The effectiveness of the parameters is confirmed by operating organizations.

Increased productivity is ensured, among other things, by facilitating the introduction of the cutting unit of the bucket into the selected rock and the possibility of efficient filling of the bucket, i.e. a greater degree of filling of the bucket in one digging stroke.

The increase in the duration of the period between repairs is ensured, among other things, by the possibility of longer use of bucket teeth without their replacement, as well as longer use of the bucket itself.

According to the results of the tests of the mileage of units for the groups of EKG-20 and EKG-15 excavators, conducted at Karelsky Okatysh JSC, after changing the design of the cutting unit of the quarry excavator bucket, the mileage of the front walls on the EKG-20 increased threefold, the bucket teeth - twice, the hoisting rope - one and a half times. Changing the design of the cutting unit of the quarry excavator bucket made it possible to eliminate the ingress of travel elements, teeth and front walls to the factory from the excavator equipment.

According to EKG-15, the increase in the travel of the front walls was recorded as one and a half times, the bucket teeth as two times, and the hoist rope as 40%.

The cutting unit of the quarry excavator bucket ensured greater filling capacity of the bucket, which also reduced the time for loading transport involved in the transportation of ore.

Increasing the mileage of the units without the need for special reinforcement and protection of the bucket walls made it possible to lighten the bucket itself, which reduced the load on the excavator's lifting equipment during operation and, in turn, also contributed to increased productivity.

Thus, the presence of an angle between the plane of the teeth seat and the axis of the handle from 120° to 124° simultaneously with the production of wedge-shaped teeth with a cutting edge length from 600 to 750 mm and an angle between the seat axis and the bisector of the angle of the wedge-shaped part of the tooth from 16° to 23°, ensures a reduction in pressure forces when introducing the working element of the excavator into the rock, contributing to an increase in work productivity, and also provides the possibility of increasing the service life of the teeth, due to maintaining the operability of the teeth until they are worn down to the edge of the seat of the front wall of the bucket.

Longer intervals between tooth replacements also contribute to increased productivity by reducing excavator downtime.

Example 1

The cutting unit of the quarry excavator bucket is used as part of a quarry excavator, comprising a handle made with the possibility of movement relative to the boom and the bucket. The bucket is fixed to the handle beam through a flange joint on its rear wall.

The cutting unit of the quarry excavator bucket contains teeth fixed on the front wall of the bucket, having a wedge-shaped working part formed by a convex upper and concave lower curvilinear edges. In this case, the angle between the plane of the tooth seat and the axis of the handle beam in the vertical plane is 120°, the angle between the plane of the tooth seat and the bisector of the angle of the wedge-shaped part of the tooth in the vertical plane is 16°, the length of the cutting edge of the teeth is 600 mm.

When digging with an excavator, the bucket with its cutting unit penetrates into the rock or soil, and its further vertical movement helps fill the bucket.

Due to the optimal value of the angle of interaction of the teeth of the cutting unit of the bucket with the soil surface and their shape, the bucket penetrates into the rock more easily and its filling occurs more efficiently throughout the entire service life of the tooth, ensuring high productivity of work.

When interacting with the rock, the teeth wear out intensively. However, the spatial orientation of the teeth in the cutting unit and their shape contribute to their longer service life, thereby increasing the duration of operation before the need to replace the teeth arises.

Maintaining the working condition of the teeth with their working part almost completely worn down ensures a long period between repairs for the bucket.

Example 2

The cutting unit of the quarry excavator bucket is used as part of a quarry excavator, containing a handle and equipped with a bucket unloading mechanism, rigidly fixed to the end of the handle by means of a corresponding handle head.

The cutting unit of the quarry excavator bucket contains teeth fixed on the front wall of the bucket, having a wedge-shaped working part formed by a convex upper and concave lower curvilinear edges. In this case, the angle between the plane of the tooth seat and the axis of the handle beam in the vertical plane is 124°, the angle between the plane of the tooth seat and the bisector of the angle of the wedge-shaped part of the tooth in the vertical plane is 23°, and the length of the cutting edge of the teeth is 750 mm.

When digging with an excavator, the bucket with its cutting unit penetrates into the rock, and its further vertical movement helps fill the bucket.

The optimal value of the angle of interaction of the teeth of the cutting unit of the bucket with the soil surface and their shape facilitate its penetration into the rock and its filling, increasing work productivity.

The spatial orientation of the teeth in the cutting unit and their shape contribute to their longer service life, increasing the duration of the bucket's operation between repairs.

When digging with an excavator, the bucket is closed - the bolt holds the unloading mechanism in its original - closed position.

When unloading the bucket, the bolt is pulled back, as a result of which the bottom flap opens under the weight of the rock load and unloading takes place.

After unloading the bucket, the unloading mechanism is returned to its original state.

The cutting unit of the mining excavator bucket can be made of metal by casting and molding using steel and standard equipment.

Thus, the cutting unit of the quarry excavator bucket ensures high excavator performance, as well as an increase in the duration of the period between repairs.

Claims (2)

1. A cutting unit of a quarry excavator bucket, comprising teeth fixed to the front wall of the bucket, having a wedge-shaped working part formed by a convex upper and concave lower curvilinear edges, characterized in that the angle between the axis of the tooth seat and the axis of the handle beam in the vertical plane is constant during digging and is from 120° to 124°, while the angle between the axis of the tooth seat and the bisector of the angle of the wedge-shaped part of the tooth in the vertical plane is from 16° to 23°, and the length of the cutting edge of the teeth is from 600 to 750 mm. 2. The unit according to item 1, characterized in that the axis of the seat of the teeth is parallel to the plane of the front wall of the bucket.