Novel screw weightlessness scale

Abstract

A novel screw weightlessness scale belongs to the technical field of weightlessness scale equipment and comprises a screw weightlessness scale body, a photoelectric switch, an air compressor, a pressure detection switch, an electromagnetic valve, a control circuit and a feeding mechanism. The feeding mechanism comprises an electromagnetic valve A, a distributing hopper and a feeding mechanism, the electromagnetic valve and a weighing hopper of the screw weightlessness scale body are installed together, and the upper end of the electromagnetic valve is connected with an exhaust pipe of an air storage tank of an air compressor; the optoelectronic switch is vertically installed on one side of the upper end in the weighing hopper, and the control circuit is installed in the electric cabinet. On the basis of the screw weightlessness scale body, in application, pressure-relief-free feeding in the weighing hopper can be achieved through the photoelectric switch, the sealed feeding mechanism, the control circuit and the like, and the probability that air is exhausted too much, an air compressor works frequently and energy is consumed is reduced; through the action of the pressure detection switch and the electromagnetic valve, the material in the weighing hopper can be at a higher constant pressure, and the material is compressed, so that a favorable technical support is provided for accurately outputting the material.

Description

Technical Field

[0001] This utility model relates to the technical field of loss-in-weight scale equipment, and in particular to a novel screw loss-in-weight scale. Background Technology

[0002] A screw loss-in-weight scale is a weighing device with intermittent feeding and continuous discharging. Because loss control is performed in the hopper, it achieves higher control accuracy. Its structure is also easy to seal, representing a significant technological improvement over screw scales in powder control. It is suitable for controlling the batching of fine materials such as cement, lime powder, and coal powder. In operation, the feeding mechanism maintains a certain material level in the weighing hopper. A motor reduction mechanism at the bottom of the hopper drives the screw conveyor impeller at a constant speed (the screw loss-in-weight scale's control system controls the motor reduction mechanism to rotate at a higher speed, resulting in a higher output of material from the screw conveyor, and vice versa). The screw conveyor then outputs material to the next process step according to a fixed discharge rate, providing reliable, accurate, and stable feeding to the next process using the material, reducing material waste and improving the consistency of mixtures of various materials.

[0003] Although existing screw loss-in-weight scales meet operational needs to some extent, they still have the following technical problems due to structural limitations. Specifically, the material entering the weighing hopper is stirred by a stirring mechanism to ensure it enters the screw conveyor's feed inlet as evenly as possible. However, because the material is in a loose state, the density and looseness of all the material at the lower end of the weighing hopper cannot be uniform. This inconsistency in density and other properties leads to inconsistent amounts of material continuously entering the next process during constant-speed screw conveyor impeller transport, negatively impacting accurate feeding. Therefore, it is particularly necessary to provide a screw loss-in-weight scale that can achieve accurate feeding as much as possible. Utility Model Content

[0004] To overcome the shortcomings of existing screw loss-in-weight scales, which are limited by their structure and have the drawbacks described in the background art, this utility model provides a new type of screw loss-in-weight scale based on the screw loss-in-weight scale body. In application, under the joint action of related mechanisms, the material in the weighing hopper can be kept at a high constant pressure. Due to compression, the material enters the feed inlet of the screw conveyor with a looseness and density that is as consistent as possible, which provides favorable technical support for accurate feeding.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A novel screw loss-in-weight scale includes a screw loss-in-weight scale body, a photoelectric switch, an air compressor, a pressure detection switch, and a solenoid valve. It also includes a control circuit and a feeding mechanism. The feeding mechanism includes a solenoid valve A and a distributing hopper. Multiple feeding pipes are installed on the upper part of the weighing hopper of the screw loss-in-weight scale body. There are at least two solenoid valves A. The upper part of one of the feeding pipes is connected to the lower end of the first solenoid valve A. The upper end of the first solenoid valve A is connected to the lower end of the discharge pipe of the feeding mechanism. Pipelines are installed on the upper and lower ends of the distributing hopper. The upper pipe is connected to the lower end of one of the feeding pipes. The end pipe is connected to the upper end of the second solenoid valve A. The upper parts of the other two feed pipes are connected to the air inlet pipe of the pressure detection switch and the lower end of the solenoid valve, respectively. The upper end of the solenoid valve is connected to the exhaust pipe of the air compressor storage tank. The photoelectric switch is vertically installed on the upper side of the weighing hopper, and the control circuit is installed in the electrical control box. The power output terminal of the pressure detection switch is electrically connected to one power input terminal of the solenoid valve. The power output terminal of the control circuit is electrically connected to the power input terminals of the two solenoid valves A, respectively. The signal output terminal of the photoelectric switch is electrically connected to the signal input terminal of the control circuit.

[0007] Furthermore, the solenoid valve, solenoid valve A, is a normally closed solenoid valve.

[0008] Furthermore, the detection distance of the photoelectric switch's probe is less than the distance between the probe and the stirring blades of the screw weightless weighing body.

[0009] Furthermore, the lower end of the dispensing hopper has a conical structure.

[0010] Furthermore, the control circuit includes an electrically connected resistor, a time relay module, and a time control switch. The positive power input terminals of the two time control switches are connected to the power output terminals of the time relay module. The negative power input terminal and the negative trigger signal input terminal of the time relay module are connected to the negative power input terminals of the two time control switches. One end of the resistor is connected to the positive trigger signal input terminal of the time relay module.

[0011] Compared with existing technologies, the advantages of this invention are as follows: Based on the screw-type loss-in-weight weigher body, this invention, through photoelectric switches, a sealed feeding mechanism, and control circuits, ensures pressure-free feeding within the weighing hopper, reducing the likelihood of excessive air discharge, frequent compressor operation, and energy consumption. The pressure detection switch and solenoid valve maintain a high and constant pressure within the weighing hopper, ensuring that the material is compressed and its density and looseness are as consistent as possible upon entering the screw conveyor's inlet, thus providing favorable technical support for accurate material output. In summary, this invention has promising application prospects. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0014] Figure 2 This is the circuit diagram of this utility model. Detailed Implementation

[0015] Figure 1 , 2 As shown, a novel screw loss-in-weight scale includes a screw loss-in-weight scale body 1, a power switch S1, a power module U1, a photoelectric switch U2, an air compressor (not shown in the figure), a pressure detection switch S2, and a solenoid valve DC1. It also has a control circuit 2 and a sealed feeding mechanism. The sealed feeding mechanism includes solenoid valves ADC2 and DC3, and a distributing hopper 31. A feeding pipe 102, communicating with the inside of the hopper 101, is welded to the upper left and upper right front and rear ends of the weighing hopper 101 of the screw loss-in-weight scale body. There are two solenoid valves A. The upper part of the first feeding pipe 102 on the left end is threadedly connected to the lower end of the first solenoid valve ADC2. A branch pipe is threadedly installed on the upper end of the first solenoid valve ADC2. The upper end of the branch pipe is connected to the feeding mechanism of the screw loss-in-weight scale body (as shown in the figure). The lower end of the discharge pipe (not shown) is connected by a thread. The distribution hopper 31 is a sealed structure. The upper end and the middle of the lower end of the distribution hopper 31 are respectively welded with a pipe that communicates with its interior. The upper pipe is connected to the lower end of the first feed pipe 102 on the left end by a thread. The lower pipe is connected to the upper end of the second solenoid valve ADC3 by a thread. The upper part of the other two feed pipes on the right end is connected to the air inlet pipe of the pressure detection switch S2 and the lower end of the solenoid valve DC1 by a thread. The upper end of the solenoid valve DC1 is connected to the exhaust pipe of the air compressor storage tank by a hose. The cylinder of the photoelectric switch U2 is vertically distributed and installed on the upper right side of the weighing hopper 101, and its probe is vertically facing downward. The power switch S1, the power module U1, and the control circuit 2 are installed on the circuit board inside the electrical control box 4.

[0016] Figure 1 , 2 As shown, solenoid valves DC1, ADC2, and DC3 are normally closed solenoid valves. The detection distance of the photoelectric switch U2's probe is less than the distance between its own probe and the lower stirring blade 103 of the screw-type weightless weighing body's stirring mechanism. The lower end of the distributing hopper 31 has a conical structure (facilitating downward movement of materials). The control circuit includes a resistor R1 and a time relay module U3, time control switches U4 and U5 connected via circuit board wiring. The positive power input pin 1 of the two sets of time control switches U4 and U5 is connected to the power output pin 5 of the time relay module U3. The negative power input pin 2 and the negative trigger signal input pin 4 of the time relay module U3 are connected to the negative power input pin 2 of the two sets of time control switches U4 and U5. One end of the resistor R1 is connected to the positive trigger signal input pin 3 of the time relay module U3.

[0017] Figure 1, 2 As shown, the power input terminals 1 and 2 of the power module U1, and the power input terminal of the screw weightless scale body 1 (M1) are connected in series with a power switch S1 and to the two poles of the 220V AC power supply via wires. The positive power output terminal 3 of the power module U1, the positive power input terminal 1 of the pressure detection switch S2, the positive power input terminal 1 of the photoelectric switch U2, and the positive power input terminal of the control circuit, as well as the pin 1 of the time relay module U3, are connected via wires. The negative power output terminal 3 of the power module U1, the negative power input terminal of the solenoid valve DC, the negative power input terminal 2 of the photoelectric switch U2, and the negative power input terminal 2 of the time relay module U3 of the control circuit are connected via wires. The power output terminal of the pressure detection switch S2 and the positive power input terminal of the solenoid valve DC1 are connected via wires. The power output terminals of the control circuit, the time switches U4 and U5, and the power input terminals of the two solenoid valves ADC2 and DC3 are connected via wires. The signal output terminal 3 of the photoelectric switch U2 and the signal input terminal of the control circuit, along with the other end of resistor R1, are connected by a wire. Figure 2 In the diagram, power module W1 is a finished product of AC 220V to DC 12V power module; resistor R1 has a resistance of 4.7K; time switches U4 and U5 are finished products of model KG316T time controllers, which have two power input terminals, two power output terminals, and seven setting buttons. By operating multiple buttons, the output time of the two power output terminals can be set; photoelectric switch U2 is a finished product of model E3F-DS30C4 infrared sensing photoelectric switch, which has two power input terminals and one signal output terminal. When the infrared beam emitted by its detector is not blocked within a certain distance, the signal output terminal outputs power; when the infrared beam emitted by the detector is blocked, the signal output terminal does not output power. The power supply (the photoelectric switch has a distance adjustment knob, which is adjusted to about 30 cm in this embodiment); the solenoid valves DC, ADC1, and DC2 are normally closed solenoid valves with a power of 2W; the time relay module U3 is a YF-29 time relay control module, which has two power input terminals, two trigger signal input terminals, one normally open power output terminal, and four setting buttons. By operating the four setting buttons, the time for the normally open power output terminal to output power can be set (after each positive and negative trigger signal is input to the two trigger signal input terminals, the normally open power output terminal will output a high level for a certain period of time); the pressure detection switch S2 is a normally closed contact adjustable pressure switch.

[0018] Figure 1 , 2As shown, this new invention is based on the screw loss-in-weight scale body 1 (the screw loss-in-weight scale body is energized and operates after the power switch S1 is turned on). In application, the feeding mechanism controls the material level in the weighing hopper 101 to maintain a certain height. The motor reduction mechanism 104 at the lower end of the weighing hopper drives the screw conveyor impeller in the screw conveyor 105 to rotate at a constant speed (when the control system of the screw loss-in-weight scale controls the motor reduction mechanism to rotate at a high speed, the screw conveyor outputs a relatively large amount of material, and vice versa). Thus, the screw conveyor 105 outputs material to the next process according to a fixed output amount, providing reliable, accurate, and stable feeding to the next process that uses the material, reducing material waste, and improving the consistency of various mixtures, etc. The above are existing mature technologies, and will not be elaborated further in this application. In this invention, after the AC 220V power supply enters the power input terminal of the power module U1, its pins 3 and 4 output a stable DC 12V power supply to the power input terminals of the pressure detection switch S2 and the control circuit, photoelectric switch, etc. When the pressure inside the weighing hopper 101 is lower than a certain level (e.g., less than 0.4 MPa), the internal contacts of the pressure detection switch S2 close, energizing the positive power input terminal of the solenoid valve DC1 and opening the valve core, allowing compressed air from the air compressor's storage tank to enter the weighing hopper 101. When the pressure inside the weighing hopper 101 is higher than a certain level (e.g., higher than 0.4 MPa), the internal contacts of the pressure detection switch S2 open, de-energizing the positive power input terminal of the solenoid valve DC1 and closing the valve core, preventing compressed air from the air compressor's storage tank from entering the weighing hopper 101. Through the above, this invention can maintain a constant pressure inside the weighing hopper 101, ensuring that the material inside the weighing hopper 101 is under a relatively high constant pressure. Because the material is compressed, its looseness and density are as consistent as possible when it enters the feed inlet of the screw conveyor 105, providing favorable technical support for accurate material output. When the material level in the weighing hopper 101 is above a certain level, the lower end of the detector head of photoelectric switch U2 is blocked by an object, so pin 3 does not output a high level. Therefore, the time control switch and time relay module will not be powered on. When the material level in the weighing hopper 101 is below a certain level, the lower end of the detector head of photoelectric switch U2 is unblocked, so pin 3 outputs a high level. This high level is stepped down and current-limited by resistor R1 and enters pin 3 of time relay module U3. Pin 5 of time relay module U3 outputs a high level for a period of time (e.g., 14 seconds) which then enters the positive power input terminals of time control switches U4 and U5.When the timer switch U4 is energized, its pins 3 and 4 output power for a certain period of time (e.g., 7 seconds) to the positive power input terminal of the solenoid valve ADC2. The solenoid valve ADC2 is energized and its valve core opens. In this way, the material output by the feeding mechanism enters the sealed distribution hopper 31 (because the distribution hopper 31 is sealed and the solenoid valve ADC3 is de-energized and its valve core is closed, the air in the weighing hopper 101 will not be discharged). After 7 seconds, the solenoid valve ADC2 is de-energized and its valve core closes. When the timer switch U5 is energized, its pins 3 and 4 output power for a certain period of time (e.g., 7 seconds) to the positive power input terminal of the solenoid valve ADC3. The solenoid valve ADC3 is energized and its valve core opens. In this way, the material in the sealed distribution hopper 31 will enter the weighing hopper 101. Because the solenoid valve ADC2 in the distribution hopper 31 is de-energized and its valve core is closed, the air in the weighing hopper 101 will not be discharged. Through the above, in this new application, the photoelectric switch, the sealed feeding mechanism, and the control circuit enable the weighing hopper to feed without pressure relief, reducing the chances of excessive air discharge, frequent operation of the air compressor, and energy consumption.

[0019] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model.

[0020] Furthermore, it should be understood that although this specification describes the embodiments, the embodiments do not necessarily contain only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A novel screw loss-in-weight scale, comprising a screw loss-in-weight scale body, a photoelectric switch, an air compressor, a pressure detection switch, and a solenoid valve, characterized in that, It also includes a control circuit and a feeding mechanism; the feeding mechanism includes a solenoid valve A and a distributing hopper. Multiple feeding pipes are installed on the upper part of the weighing hopper of the screw loss-in-weight scale body. There are at least two solenoid valves A. The upper part of one feeding pipe is connected to the lower end of the first solenoid valve A, and the upper end of the first solenoid valve A is connected to the lower end of the discharge pipe of the feeding mechanism. Pipes are installed on the upper and lower ends of the distributing hopper. The upper pipe is connected to the lower end of one of the feeding pipes, and the lower pipe is connected to the upper end of the second solenoid valve A. The upper parts of the other two feeding pipes are connected to the air inlet pipe of the pressure detection switch and the lower end of the solenoid valve, respectively. The upper end of the solenoid valve is connected to the exhaust pipe of the air compressor's air tank. The photoelectric switch is vertically installed on one side of the upper end inside the weighing hopper. The control circuit is installed in the electrical control box. The power output terminal of the pressure detection switch is electrically connected to one power input terminal of the solenoid valve. The power output terminal of the control circuit is electrically connected to the power input terminals of the two solenoid valves A, respectively. The signal output terminal of the photoelectric switch is electrically connected to the signal input terminal of the control circuit.

2. The novel screw-type loss-in-weight scale according to claim 1, characterized in that, Solenoid valve, solenoid valve A is a normally closed valve core solenoid valve.

3. The novel screw-type loss-in-weight scale according to claim 1, characterized in that, The detection distance of the photoelectric switch probe is less than the distance between the probe and the stirring blades of the screw weightless weighing body.

4. The novel screw-type loss-in-weight scale according to claim 1, characterized in that, The lower end of the hopper has a conical structure.

5. A novel screw-type loss-in-weight scale according to claim 1, characterized in that, The control circuit includes an electrically connected resistor, a time relay module, and a time control switch. The positive power input terminals of the two time control switches are connected to the power output terminals of the time relay module. The negative power input terminal and the negative trigger signal input terminal of the time relay module are connected to the negative power input terminals of the two time control switches. One end of the resistor is connected to the positive trigger signal input terminal of the time relay module.

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