An adjustable aggregate screening device

Abstract

This invention discloses an adjustable aggregate screening device, comprising a base, a rocker arm, a rectangular screen, and a rectangular screen driver. The rocker arm includes a sleeve, a sliding rod that slides vertically with the sleeve, and a spring fitted on the sliding rod. The rectangular screen includes a rectangular material frame, upper horizontal bars fixed at equal intervals at the lower part of the rectangular material frame, a lower screen located below the upper horizontal bars, and an adjuster for adjusting the position of the lower screen longitudinally. This adjustable aggregate screening device integrates longitudinal reciprocating oscillation and vertical vibration functions, which can improve the screening efficiency for needle-like and flaky aggregates. Furthermore, it designs the ratio of the vertical amplitude to the horizontal amplitude of the rectangular screen to be 0.25–0.5, which significantly improves the screening efficiency for needle-like and flaky aggregates compared to other amplitude ratio ranges.

Description

Technical Field

[0001] This invention relates to the field of aggregate production technology, and in particular to an aggregate sorting device. Background Technology

[0002] Aggregates, also known as aggregates, are one of the main components of concrete. They mainly serve as the skeleton of concrete and also as inexpensive fillers for cementitious materials.

[0003] According to the "Specifications for Aggregate Testing in Highway Engineering," particles whose ratio of maximum length (or width) to minimum thickness (or diameter), measured with vernier calipers, is greater than 3 can be classified as flaky or needle-like particles. Due to the inherent heterogeneity of rock properties and limitations imposed by the crushing method, flaky or needle-like particles are inevitably produced during aggregate production. These particles increase the frictional force of fresh concrete during flow, worsen its workability, reduce its encapsulation and cohesion, and tend to align in one direction, making them difficult to compact and prone to breakage under stress. Furthermore, flaky or needle-like crushed stone has lower toughness than ordinary granular crushed stone, thus affecting the strength properties of concrete. A significant decrease in concrete strength can severely impact engineering projects. Therefore, reasonable control of the flaky or needle-like particle content is essential for aggregate application and ensuring concrete performance.

[0004] In existing technologies, square-hole or round-hole screens are commonly used for screening aggregates. However, due to the limitations of their screen hole shape, square-hole or round-hole screens can only classify ordinary particle sizes and cannot effectively screen out needle-shaped or flaky particles in the aggregate. At the same time, existing vibrating screens driven by vibrating motors mainly vibrate up and down, with a small horizontal vibration amplitude, resulting in mediocre screening effects when the material is thick. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an adjustable aggregate screening device to solve the technical problem of screening out needle-shaped and flaky particles in aggregates.

[0006] The adjustable aggregate screening device of the present invention includes a base, four rocker arms with their lower ends hinged to the base and arranged in a rectangular shape, and a rectangular screen hinged to the upper ends of the four rocker arms. Each rocker arm includes a sleeve with its lower end hinged to the base, a slide rod that slides vertically with the sleeve, and a spring that is sleeved on the slide rod with one end pressing against the sleeve and the other end pressing against the slide rod. The rectangular screen includes a rectangular material frame hinged to the upper end of the slide rod, upper horizontal bars that are fixed at equal intervals at the lower part of the rectangular material frame, a lower screen located below the upper horizontal bars, and an adjuster for adjusting the position of the lower screen along the longitudinal direction. The lower screen includes a screen frame that slides vertically with the lower part of the rectangular material frame and lower horizontal bars that are arranged at equal intervals on the screen frame. A long slit-shaped screen hole is formed between the upper horizontal bars and the lower horizontal bars for needle-shaped aggregates to fall.

[0007] The adjustable aggregate screening device also includes a rectangular screen driver, which includes a dual-shaft motor mounted on the base, a crank connected to the power output shaft of the dual-shaft motor, a connecting rod with one end hinged to the crank and the other end hinged to the rectangular material frame, and a discharge chute mounted on the base and located below the rectangular screen.

[0008] Furthermore, the regulator includes a connecting plate disposed on a rectangular material frame, a lead screw disposed on the connecting plate and rotatably cooperating with the connecting plate, and a handwheel or stepper motor for driving the lead screw to rotate. The lead screw is threadedly connected to the screen frame of the lower screen.

[0009] Furthermore, the ratio of the vertical amplitude to the horizontal amplitude of the rectangular screen is 0.25 to 0.5.

[0010] The beneficial effects of this invention are:

[0011] 1. The adjustable aggregate screening device of the present invention allows the rectangular screen to oscillate back and forth in the longitudinal direction during the screening process, while its position also fluctuates in the vertical direction. Furthermore, the sliding rod and spring in the rocker arm allow the rectangular screen to vibrate up and down during the movement. During the longitudinal reciprocating motion, the rectangular screen can more easily change the horizontal needle-like aggregates into an inclined or vertical state, which is beneficial to the downward movement of the needle-like aggregates. At the same time, the vertical vibration of the rectangular screen can accelerate the downward movement of the needle-like aggregates. Therefore, the adjustable aggregate screening device of the present invention, which integrates the functions of longitudinal reciprocating oscillation and vertical vibration, can improve the screening efficiency of needle-like aggregates.

[0012] 2. The adjustable aggregate screening device of the present invention has an adjustable lower screen position. Adjusting the lower screen position can change the width of the long slit screen holes, thereby enabling different screening decisions based on the size grade of the aggregate. For example, if the ordinary-shaped aggregate particles in the aggregate are large, the width of the long slit screen holes can be adjusted to be larger, which can improve screening efficiency; when the ordinary-shaped aggregate particles in the aggregate are small, the width of the long slit screen holes can be adjusted to be smaller to meet the screening requirements.

[0013] Furthermore, after screening, the width of the long slit screen opening can be adjusted to the maximum, which allows the qualified aggregate obtained from screening to be discharged quickly. Compared with other methods of removing qualified aggregate from rectangular screens, the adjustable aggregate screening device of this invention has a faster and more convenient unloading speed.

[0014] 3. Experimental verification shows that the adjustable aggregate screening device of the present invention designs the ratio of vertical amplitude to horizontal amplitude of rectangular screen to be 0.25 to 0.5. Compared with other amplitude ratio ranges, it can significantly improve the screening efficiency of needle-shaped and flaky aggregates. Attached Figure Description

[0015] Figure 1This is a three-dimensional structural diagram of an adjustable aggregate screening device.

[0016] Figure 2 This is a three-dimensional schematic diagram of an adjustable aggregate screening device from another perspective.

[0017] Figure 3 This is a half-sectional schematic diagram of an adjustable aggregate screening device.

[0018] Figure 4 This is a schematic diagram of the three-dimensional structure of the lower sieve.

[0019] Figure 5 This is a schematic diagram showing the hinge centers of the crank, connecting rod, and rocker arm, as well as the distances between the hinge centers.

[0020] Figure 6 This is a schematic diagram showing the positional state of the crank, connecting rod, and rocker when the joystick swings to its limit to the right.

[0021] Figure 7 This is a schematic diagram showing the positional state of the crank, connecting rod, and rocker when the rocker arm swings to its leftmost limit.

[0022] Figure 8 This is a diagram showing the positional relationship of the joystick when it swings left and right.

[0023] Figure 9 This is a graph showing the relationship between the ratio of vertical to horizontal amplitude of a rectangular screen and the screening effect. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] As shown in the figure, the adjustable aggregate screening device of this embodiment includes a base 1, four rocker arms 2 with their lower ends hinged to the base and arranged in a rectangle, and a rectangular screen hinged to the upper ends of the four rocker arms. Each rocker arm 2 includes a sleeve 21 with its lower end hinged to the base, a slide rod 22 that slides up and down with the sleeve, and a spring 23 that is sleeved on the slide rod with one end pressing against the sleeve and the other end pressing against the slide rod. The rectangular screen includes a rectangular material frame 3 hinged to the upper end of the slide rod, upper horizontal bars 4 that are fixed at equal intervals at the lower part of the rectangular material frame, a lower screen located below the upper horizontal bars, and an adjuster for adjusting the position of the lower screen along the longitudinal direction. The lower screen includes a screen frame 5 that slides along the longitudinal direction with the lower part of the rectangular material frame and lower horizontal bars 6 that are arranged at equal intervals on the screen frame. A long slit-shaped screen hole 7 is formed between the upper and lower horizontal bars for the needle-like aggregate to fall.

[0026] The adjustable aggregate screening device also includes a rectangular screen driver, which includes a dual-shaft motor 8 mounted on the base, a crank 9 connected to the power output shaft of the dual-shaft motor, a connecting rod 10 with one end hinged to the crank and the other end hinged to the rectangular material frame, and a discharge chute 11 mounted on the base and located below the rectangular screen.

[0027] In this embodiment, the regulator includes a connecting plate 12 mounted on a rectangular material frame, a lead screw 13 mounted on the connecting plate and rotatably engaged with the connecting plate, and a handwheel 14 for driving the lead screw to rotate. The lead screw is threadedly connected to the screen frame of the lower screen. Of course, in different embodiments, the handwheel can also be replaced by a stepper motor, thus achieving automatic adjustment.

[0028] In this embodiment, the adjustable aggregate screening device adjusts the long-slit screen opening according to the thickness of the needle-like and flaky aggregate to be screened. Adjustment is achieved by rotating the handwheel and screw, which moves the lower screen. The adjustment operation is simple and convenient. During screening, the aggregate is loaded into the rectangular screen, and then the rectangular screen is driven by the dual-shaft motor 8 to screen the aggregate. In this embodiment, the rectangular screen, driven by the dual-shaft motor 8, crank 9, and connecting rod 10, can reciprocate longitudinally and also oscillate vertically. Furthermore, the sliding rod and spring in the rocker arm allow the rectangular screen to vibrate vertically during movement. The longitudinal reciprocating motion of the rectangular screen makes it easier to change the horizontal needle-like and flaky aggregate into an inclined or vertical state, thus facilitating the downward movement of the aggregate. Simultaneously, the vertical vibration of the rectangular screen accelerates the downward movement of the needle-like and flaky aggregate. Therefore, the adjustable aggregate screening device, which integrates longitudinal reciprocating oscillation and vertical vibration functions, can improve the screening efficiency of needle-like and flaky aggregate.

[0029] In this embodiment, the adjustable aggregate screening device has an adjustable lower screen position. Adjusting the lower screen position can change the width of the long slit screen opening, thereby enabling different screening decisions based on the size grade of the aggregate. For example, if the ordinary-shaped aggregate particles in the aggregate are large, the width of the long slit screen opening can be adjusted to be larger, which can improve screening efficiency. When the ordinary-shaped aggregate particles in the aggregate are small, the width of the long slit screen opening can be adjusted to be smaller to meet the screening requirements.

[0030] As an improvement to the above embodiment, the ratio of the vertical amplitude to the horizontal amplitude of the rectangular screen is 0.25 to 0.5. Figures 5 to 8 As shown, the vertical and horizontal amplitudes can be calculated using the following formulas:

[0031] State 1 geometric relation:

[0032]

[0033] State 2 geometric relations:

[0034]

[0035] Horizontal amplitude:

[0036]

[0037] Vertical amplitude:

[0038] A y =1-MIN[y1, y2]=l2·{1-MIN[sin(α1+β), sin(α2+β)]} (2)

[0039] Through aggregate screening experiments conducted on an adjustable aggregate screening device, it was found that the screening efficiency for needle-shaped and flaky aggregates is related to the ratio of the vertical amplitude to the horizontal amplitude of the rectangular screen. Figure 9 The curve relationship is shown. In this embodiment, the adjustable aggregate screening device is designed with the ratio of the vertical amplitude to the horizontal amplitude of the rectangular screen set in the range of 0.25 to 0.5, which can achieve the best screening effect for needle-shaped and flaky aggregates.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An adjustable aggregate screening device, characterized in that: The device includes a base, four rocker arms hinged to the base at their lower ends and arranged in a rectangular shape, and a rectangular screen hinged to the upper ends of the four rocker arms. Each rocker arm includes a sleeve hinged to the base at its lower end, a slide rod that slides vertically with the sleeve, and a spring that is sleeved on the slide rod with one end pressing against the sleeve and the other end pressing against the slide rod. The rectangular screen includes a rectangular material frame hinged to the upper end of the slide rod, upper horizontal bars fixed at equal intervals at the lower part of the rectangular material frame, a lower screen located below the upper horizontal bars, and an adjuster for adjusting the position of the lower screen longitudinally. The lower screen includes a screen frame that slides longitudinally with the lower part of the rectangular material frame and lower horizontal bars arranged at equal intervals on the screen frame. A long slit-shaped screen hole is formed between the upper and lower horizontal bars for needle-like aggregates to fall. The adjustable aggregate screening device also includes a rectangular screen driver, which includes a dual-shaft motor mounted on the base, a crank connected to the power output shaft of the dual-shaft motor, a connecting rod with one end hinged to the crank and the other end hinged to the rectangular material frame, and a discharge chute mounted on the base and located below the rectangular screen. The ratio of the vertical amplitude to the horizontal amplitude of the rectangular screen is 0.25 to 0.

5.

2. The adjustable aggregate screening device according to claim 1, characterized in that: The regulator includes a connecting plate mounted on a rectangular material frame, a lead screw mounted on the connecting plate and rotating in cooperation with the connecting plate, and a handwheel or stepper motor for driving the lead screw to rotate. The lead screw is threadedly connected to the screen frame of the lower screen.

Images