Analysis on the characteristics of the latest bott

This paper expounds the structural characteristics of the new bottom discharge bucket, the principle and characteristics of the self-locking mechanism, the selection and calculation method of the self-locking protection angle, and the design of the opening device. It solves the problem of difficult unloading of the old bucket in the mine shaft, and has industrial application value

keywords bucket; Bottom unloading; Self locking

0 preface

when drilling and blasting methods are used to develop shafts, buckets are used as lifting containers to load the blasted loose rocks, which are lifted to the surface by winches. Because the bottom of the old bucket is closed and fixed and cannot be opened, it brings a lot of inconvenience to unloading. This new bottom unloading bucket introduced in this paper solves the problem of difficult unloading

1 structure and principle of bottom unloading bucket

1.1 bucket structure

as shown in Figure 1, different from the old bucket, its bottom is a double open movable bottom. The two halves of the bucket bottom are hinged with the bucket body through the rotating shaft and sleeve. The closed state of the movable bucket bottom is maintained by the self-locking mechanism and self-locking. The opening device is used to release the self-locking to open the movable bottom, and the gravity of the bucket bottom always keeps the bucket bottom open. Each side of the double opening barrel bottom can be opened to 90 ° at most, that is, the plane of the barrel bottom plate is parallel to the barrel axis, so as to reduce the impact and wear of the rock on the bottom plate during unloading. When closing the barrel bottom, just hold the barrel bottom flat. At this time, the self-locking mechanism acts to restore the self-locking, so that the barrel bottom is closed

Figure 1 bottom discharge bucket

1 - lifting beam; 2 - can body; 3 - opening device

4 - self locking mechanism; 5 - movable bucket bottom

6 - rotating shaft; 7 - the principle of sleeve

1.2

is shown in Figure 2. The self-locking mechanism of the left barrel bottom is composed of frame connecting rod 1, connecting rod 2, frame connecting rod 3 and limit stop iron 7. The self-locking mechanism of the right barrel bottom is composed of a rack connecting rod 4, a connecting rod 5, a rack connecting rod 6 and a limit stop iron 8. The left barrel bottom 9 and the right barrel bottom 10 are respectively connected with the connecting rod 1 and 7. On average, the tension machine is protected twice a month, and 6 is fixedly connected. Both groups of self-locking mechanisms are designed according to the principle of double rocker mechanism. After the barrel bottom is closed, the dead point of the mechanism is used for self-locking, and then the self-locking is released through the opening device to realize the automatic opening of the barrel bottom. In order to ensure reliable self-locking, effective self-locking protection measures are taken

Figure 2 self locking mechanism

1 - connecting rod; 2 - connecting rod; 3 - connecting rod

4 - connecting rod; 5 - connecting rod; 6 - connecting rod

7, 8 - limit stop iron; 9 - left bucket bottom; 10 - right barrel bottom

the solid line in Figure 2 indicates the position of each rod when the barrel bottom is closed. At this time, points c and C1 slightly cross the dead line, that is, the connecting line between BD and b1d, and are located below the line, and are blocked by the limit stop iron, so that the mechanism is in the self-locking protection state, α It is a self-locking protection angle. The double dotted line in the figure indicates the position of each rod and barrel bottom when the barrel bottom is opened to the maximum state

in the mechanism, the connecting rods 1 and 6 are connected with the rotating shaft at a and A1 through flat keys. Point D is a common central pin shaft, which is fixed on the outer surface of the can body. The limit stops 7 and 8 are also fixed on the can body. Their positions are just so that when the can bottom is closed, the connecting rod hinge points c and C1 can reach the self-locking protection angle after slightly crossing the dead center line α It is blocked by the blocking iron, so that it can no longer move down, playing the role of self-locking protection

1.3 features

the first feature of this self-locking mechanism is the use of smooth self-locking, that is, after the barrel bottom is closed, the rods 2 and 3, 4 and 5 under the action of their own gravity, their hinge points c and C1 automatically sag below the dead line and are in the self-locking protection position limited by the retaining iron, so the operation is simple. The second feature is that when opening the barrel bottom, when points c and C1 are pulled upward by the chain link of the opening device to slightly exceed the dead center line, the self-locking is released, and the barrel bottom rotates clockwise and counterclockwise around the rotation axis A and A1 under its own gravity. Its direction is consistent with the direction of the action line of the gravity of the barrel inner material on the barrel bottom. Therefore, the impact and wear of the barrel bottom plate when the material falls are less integrated, stable and reliable, and convenient to use, Therefore, the bucket bottom has a long service life. The third feature is that due to the adoption of the split barrel bottom that can be opened at the same time along the center line, the material flow is concentrated during unloading, vertically downward, and the barrel body has good stability in the air without large shaking. The fourth feature is that when the self-locking protection angle is reasonably determined α Later, the self-locking of the mechanism is very reliable, and when the mating surface of each hinge point of the self-locking mechanism is worn, the self-locking protection angle increases and the self-locking property is enhanced, so the self-locking is more reliable

2 self locking protection angle α Selection and calculation of

2.1 selection of self-locking angle

in order to make the mechanism self-locking reliable and ensure the requirements of use safety, the mechanism must have sufficient self-locking reliability when the barrel bottom is closed. What determines the reliability of self-locking is the size of self-locking protection force F4 (that is, the force of hinge point C and C1 pressing against the limit stop iron), and it is related to the self-locking protection angle α (see Figure 2) is closely related to the size of the self-locking protection angle α Increase, the self-locking protection force F4 increases, and the force F5 of pulling the opening handle also increases, α If the angle is too large, it will affect the tightness of closing the barrel bottom. On the contrary, the self-locking protection angle is reduced, the self-locking protection force is reduced, and the force of pulling the opening handle is also reduced, but too small can not ensure the reliable self-locking of the mechanism, which affects the use safety of the bucket. Generally, the self-locking protection angle is 1 °≤ α The range ≤ 4 ° is suitable. Self locking protection angle α The size of is controlled by the limit stop iron, and the position of the limit stop iron should be designed according to the selected self-locking protection angle. The self-locking protection angle is well selected and the self-locking protection force is appropriate, which can not only make the self-locking of the mechanism meet the requirements, but also make the force F5 of pulling the handle of the opening device appropriate when opening the barrel bottom

2.2 calculation

the size of self-locking protection angle can also be determined by calculation method. When the basic size of each rod of self-locking mechanism and opening device is preliminarily determined, that is, a total of 8 terminal boxes and 1 plug-in can be calculated by calculation method. Take the self-locking mechanism of the right half of the barrel bottom as an example for analysis, as shown in Figure 3, simplify the gravity of the right half of the barrel bottom itself and the gravity of the material it bears into a concentrated force F1 acting on the partition surface of the barrel bottom. From the figure, it can be seen that F2 is generated by F1 because of the self-locking protection angle α In the presence of, F2 turns into F3, and f3=f ′ 3. The resultant force F4 of F3 and f ′ 3 is the self-locking protective force, with the direction downward. F5 is the force of pulling the handle when opening the bottom of one side barrel. F '4 is generated by F5, and the direction is upward, and f' 4=f4. Considering the ergonomic requirements, when opening the barrel bottoms on both sides at the same time, the force F5 pulling the opening handle should be 4. The swing radius of the pendulum: r280 mm should not be greater than 80 n, so for opening one side, F5 should not be greater than 40 n. Based on the above analysis, the calculation formula of self-locking protection force and self-locking protection angle can be derived as follows:

self-locking protection angle α And the self-locking protection force F4 should take different values according to the size of the load. The larger value should be taken when the load is small when the load is large, so as to achieve reliable self-locking and easy opening. If the calculated value is too large or too small, the appropriate self-locking protection angle and self-locking protection force can be obtained by adjusting the length of relevant members. Generally, L4 and L5 are adjusted first, and then the length of other members is adjusted when they are not satisfied. After one or several adjustments, the appropriate self-locking protection angle and self-locking protection force can be obtained

Figure 3 force diagram of self-locking and opening mechanism of left half barrel bottom

1 - opening handle; 2 - zipper; 3 - connecting rod; 4 - connecting rod; 5 - connecting rod; 6-right barrel bottom

Figure 4 opening device

1-ear plate; 2 - horizontal axis; 3 - open handle; 4 - zipper; 5 - elastic fixed card; 6 - can body; 7 - composition and characteristics of connecting rod

3 opening device

3.1 composition

as shown in Figure 4, the opening device is composed of ear plate 1, horizontal shaft 2, opening handle 3, zipper 4, elastic fixing card 5 and other parts. The ear plate is fixed on the can body, the opening handle is installed on the ear plate through the horizontal shaft, and the horizontal shaft is statically connected with the upper sleeve of the opening handle, which is fixed by a pin. The upper fixing ring of the two zippers is fixedly connected with the shaft heads at both ends of the horizontal shaft, and the lower fixing ring is fixedly connected with the connecting rod at the hinge points c and C1 (Fig. 2) of the self-locking mechanism. When the opening handle is pulled outward, the zipper drives the connecting rod hinge points c and C1 of the self-locking mechanism to move upward at the same time. When it crosses the dead line, the self-locking is released and the barrel bottom is opened. In order to ensure the safe self-locking of the self-locking mechanism when the barrel bottom is closed, the opening device is designed so that the handle is in a natural hanging state when the barrel bottom is closed. Therefore, the accidental action of the handle will not cause the self-locking mechanism to release the self-locking due to the gravity of the handle. In order to be more secure, an elastic fixing card is set on the barrel bottom near the handle. When the barrel bottom is closed, open the handle close to the barrel wall and in the original position parallel to the barrel wall, hook the handle with the hook of the elastic fixing card to make it fixed, which plays the role of a safety card. When the handle is opened, pull the hook to pull the handle

3.2 effect

the bottom discharge bucket has been made and put into trial use in the development of mine shaft. During the three-month test period, the bucket shows the advantages of bottom discharge. While improving the production efficiency, it not only reduces the labor intensity of workers, but also ensures safe production, and achieves good economic benefits. It is popular with users. At present, the bucket is still in safe operation

4 conclusion

the new bottom discharge bucket has reasonable structure, beautiful appearance, reliable self-locking, convenient operation, easy fabrication and simple maintenance. Compared with the old bucket, it has certain novelty and strong applicability, which not only solves the problem of difficult unloading, but also opens up a new way for the development of bucket to automatic unloading. With its continuous improvement in practice, the bottom discharge bucket will play its due role in industrial production