Control circuit for a snow machine with automatic braking

Abstract

This utility model discloses an automatic braking snow sander, including a motor drive circuit and two detection circuits (left and right) for detecting the snow sander belt's deviation to the left or right. The left detection circuit, right detection circuit, and motor drive circuit are connected in series. Each detection circuit includes a photoelectric sensor, a signal amplifier, an anti-vibration delay processing circuit, a motor drive circuit, and a sander belt reset mechanism. Its key feature is that, based on existing technology, the detection circuit is replaced with a control circuit composed of purely electrical components, simplifying the control system. Because the high-speed running snow sander belt does not experience mechanical contact wear, there are no mechanical structural failures, and there is no need to replace mechanical components such as the L-shaped position linkage, greatly reducing the chance of the snow sander belt breaking due to wear, thus effectively protecting the grinding head and other parts from collateral damage. This achieves a "braking" effect, stopping the snow sander belt and preventing accidents. Furthermore, due to the simplified structure, the reliability of the control system is improved, and the amount of system programming is reduced, making delay time adjustment more convenient.

Description

Technical Field

[0001] This utility model relates to the field of belt sanding, specifically to the control circuit of a snowflake sander with automatic braking. Background Technology

[0002] Stainless steel sheets from steel mills undergo passivation, forming a dense passivation film on their surface. During the color plating process, this passivation film can affect the adhesion between the stainless steel substrate and the plating layer. If not removed, it can lead to blistering and peeling. Snowflake sanding can completely remove this passivation film from the stainless steel sheet surface. Currently, the most common surface textures on colored stainless steel sheets are brushed and mirror finishes. The most common brushing processes for brushed finishes are snowflake sanding + regular sanding and snowflake sanding + brushing. Snowflake sanding removes most of the contaminants that may have been present on the sheet before plating, resulting in a uniform color. Ensuring a consistent substrate color before plating is crucial for achieving a uniform color after plating.

[0003] In existing technologies, the snowflake sanding process for stainless steel plates is generally implemented using a snowflake sanding machine for automated production. The key components of this machine are the snowflake sanding belt and the grinding head. The snowflake sanding belt is vertically mounted on two rollers on the upper and lower parts of the machine frame. One of these rollers is driven by a motor, and the upper roller has a small back-and-forth oscillating device that drives the snowflake sanding belt to vibrate back and forth, thus achieving repeated sanding between the snowflake sanding belt and the stainless steel plate. (Reference) Figure 1 The diagram illustrates that the back-and-forth vibration of the snowflake sanding belt caused by the swinging device can lead to lateral displacement of the belt. Therefore, two L-shaped linkages are installed on the frame. These linkages are hinged to the frame and are located on the left and right sides of the snowflake sanding belt. When the snowflake sanding belt deviates to the left or right, the linkages deflect outwards. Each linkage is backed by a photoelectric sensor / limit switch, which is mounted on the frame and normally blocked by the linkages. When the linkages deflect outwards, the sensors / limit switches are exposed or activated, generating an electrical signal—the deflection signal of the snowflake sanding belt—which is transmitted to the controller. The controller then stops the motor that drives the roller, thus achieving a "braking" effect. After the snowflake sanding belt resets, the motor is restarted to continue sanding the stainless steel plate.

[0004] However, in the aforementioned technical solution for detecting and controlling the side deviation signal of the snowflake abrasive belt, the combination of the L-shaped position linkage and the photoelectric sensor / limit switch, as an electromechanical composite sensor component, is prone to generating frequent and unstable signals. For example, if the snowflake abrasive belt accidentally deflects and then resets, it can easily cause misjudgment by the control system. Simultaneously, when the snowflake abrasive belt rolling on the roller contacts the L-shaped position linkage, it easily leaves scratches, leading to wear and tear over time and requiring frequent replacement of parts. Alternatively, due to harsh working environments, the L-shaped position linkage may become sluggish and jammed due to rust on the pin, causing inconvenience to production and adding considerable maintenance work. If a limit switch is used, its failure or malfunction is generally difficult to detect, which can also cause the controller to fail to receive the snowflake abrasive belt deviation signal. More seriously, if the high-speed running snowflake abrasive belt is mechanically damaged and breaks, it can cause the grinding head and other components to be scrapped, resulting in significant losses for the entire system. Utility Model Content

[0005] In view of the above-mentioned technical problems existing in the prior art, this utility model makes technical improvements to the prior art and provides the following technical solution for the control circuit of a snow sander with automatic braking.

[0006] A control circuit for an automatically braking snow sander is characterized in that the control circuit includes a motor drive circuit and two detection circuits for detecting the snow sander belt's deviation to the left or right. These detection circuits are a left detection circuit and a right detection circuit, respectively, with identical circuit structures. The left detection circuit, the right detection circuit, and the motor drive circuit are connected in series. Each detection circuit includes a photoelectric sensor for detecting the snow sander belt's deviation to the left or right, a signal amplifier for receiving the photoelectric sensor's control signal, an anti-jitter delay processing circuit to prevent signal jitter, a motor drive circuit controlled by the anti-jitter delay processing circuit, and a sander belt reset mechanism to reset the deviated snow sander belt. The photoelectric sensor, signal amplifier, and anti-jitter delay processing circuit are connected in series before being connected to the motor drive circuit. The sander belt reset mechanism is connected to the sander belt reset output terminal of the signal amplifier.

[0007] The working principle is as follows: The photoelectric sensor is installed on the snow sander, matching the left and right edges of the snow sander's belt so that the edges of the snow sander belt do not obstruct the photoelectric sensor. When the snow sander belt is in operation, whether it shifts to the left or right, the photoelectric sensor's field of view will be obstructed, and the photoelectric sensor will output a drive signal, driving the signal amplifier to activate. At this time, the signal amplifier outputs two signals: The first signal serves as the signal to drive the sanding belt reset mechanism, used to reset the offset snowflake sanding belt; The second signal serves as the signal for the motor driving the snowflake sander belt. It undergoes delayed anti-vibration processing in the anti-vibration delay processing circuit to prevent frequent motor starts and stops caused by normal short-term deviations. After vibration processing in the anti-vibration delay processing circuit, the circuit sends a motor stop command to the motor drive circuit after a delay to prevent the snowflake sander belt from deviating by a larger distance, which would affect the quality of the polished product.

[0008] Furthermore, the signal amplifier is a low-power relay, the output signal terminal of the photoelectric sensor is electrically connected to the coil of the low-power relay, and the first normally open contact of the low-power relay is the output terminal and electrically connected to the signal amplifier.

[0009] Furthermore, the anti-jitter delay processing circuit is a delayed disconnection time relay with a delayed disconnection contact, and the coil of the delayed disconnection time relay is electrically connected to the first normally open contact of the low-power relay.

[0010] Furthermore, the motor drive circuit is a power relay with a higher power rating than the low-power relay, and the normally closed contact of the power relay is electrically connected to the motor it drives.

[0011] Furthermore, a start / stop electrical module is connected in series between the motor drive circuit and the motor. The start / stop electrical module includes a start button, a stop button, and a self-locking intermediate relay. The coils of the stop button, start button, and self-locking intermediate relay are connected in series in sequence. One normally open contact of the self-locking intermediate relay is connected in parallel across the start button. The non-connected end of the stop button is electrically connected to the normally closed contact of the power relay. The coil of the self-locking intermediate relay is electrically connected to the N pole of the power supply. The motor is electrically connected to the power supply through the normally open contact of the power relay.

[0012] Furthermore, the sanding belt reset mechanism includes an air spray gun that can blow the deviated snowflake sanding belt back to its original position and a solenoid valve that controls the opening and closing of the air spray gun. The solenoid valve is electrically connected to the output terminal of the second normally open contact of a low-power relay.

[0013] Furthermore, the control circuit also includes a vibration indicator light that indicates the working status of the snowflake sander belt, and the vibration indicator light is electrically connected to the third normally open contact output terminal of the low-power relay.

[0014] The specific working principle of the control circuit of the automatic braking snow sander is as follows: First, the photoelectric sensor is installed on the snow sander, matching the left and right edges of the snow sander's belt so that the left and right edges of the snow sander belt do not obstruct the photoelectric sensor. When the snow sander belt is in operation, whether it shifts to the left or right, the photoelectric sensor's field of vision will be obstructed. The photoelectric sensor will then output a drive signal, which will drive a low-power relay acting as a signal amplifier. At this time, the low-power relay outputs two signals through its normally open contacts: First signal: The second and third normally open contacts of the low-power relay close, the shaking indicator light and the solenoid valve are energized, and the air gun connected to the air source blows high-pressure air at the snowflake sander belt to blow the deviated snowflake sander belt back to its normal position. At this time, the left and right edges of the snowflake sander belt are no longer blocking the photoelectric sensor, the low-power relay is de-energized, the second normally open contact of the low-power relay opens, the solenoid valve is de-energized, and the air gun closes to form a feedback closed loop; at the same time, the third normally open contact of the low-power relay closes, and the shaking indicator light illuminates. The second signal: The first normally open contact of the low-power relay closes, energizing the coil of the delayed disconnect time relay, which serves as the anti-jitter delay processing circuit. Since the normally closed contact of the delayed disconnect time relay has a delayed disconnection effect, and this delay can be adjusted and set on the delayed disconnect time relay, it achieves signal anti-jitter action, preventing frequent motor starts and stops caused by normal short-term offsets. In this case, the delayed disconnect time relay has two options: First, if the delay time has not elapsed and the snowflake sand belt returns to its normal position, the photoelectric sensor withdraws the offset signal, the low-power relay loses power, and the normally closed contact of the delayed disconnection time relay closes again, without affecting the normal operation of the motor. Secondly, if the delay time expires and the low-power relay is not de-energized, the normally closed contact of the delayed disconnection time relay will open, the coil of the power relay will be de-energized, the normally closed contact of the power relay will open, and the motor will stop, thus achieving a "braking" effect, stopping the snowflake sanding belt from moving, preventing the snowflake sanding belt from deviating a larger distance, preventing accidental detachment and damage to the grinding head and other components, and also preventing any impact on the quality of the product being ground. Beneficial effects

[0015] Compared to existing technologies, this utility model provides an automatic braking snow sander with the following advantages: The device has a simple and reasonable structure, abandoning the easily damaged electromechanical composite sensor assembly and instead using a control circuit composed of purely electrical components. This simplifies the control system. Since the high-speed running snow sander belt does not experience wear due to mechanical contact, there are no mechanical structural failures, and there is no need to replace mechanical components such as the L-shaped position linkage. This greatly reduces the chance of the snow sander belt breaking due to wear, effectively protecting the grinding head and other parts from collateral damage. When the snow sander belt deviates from its normal position beyond the time limit set by the delayed disconnection time relay, the normally closed contact of the delayed disconnection time relay opens, causing the motor to lose power and stop, thus achieving a "braking" effect and stopping the snow sander belt, preventing accidents. Furthermore, due to the simplified structure, the reliability of the control system is improved, and the amount of system programming is reduced, making delay time adjustment more convenient. Attached Figure Description

[0016] Figure 1This is a schematic diagram showing the arrangement of the snowflake sanding belt and electromechanical composite sensor assembly in a conventional snowflake sander. Figure 2 This utility model Figure 1 Schematic diagram showing the layout of the automatic braking snowflake-shaped abrasive belt and the electromechanical composite sensor assembly; Figure 3 This utility model Figure 1 System closed-loop control block diagram of a snow sander with automatic braking; Figure 4 This utility model Figure 1 Block diagram of the control circuit principle of an automatic braking snow sander; Figure 5 This is a schematic diagram of the control circuit of the snow sander with automatic braking according to this utility model.

[0017] Key reference numerals in the diagram: 1-Snowflake sander belt; 2-Roller shaft; 3-L-shaped position linkage; 4-Photoelectric sensor / limit switch; 5-Air spray gun; DY1-Photoelectric sensor; SB1-Start button, SB2-Stop button; KM1-Self-locking intermediate relay; KM2-Small power relay; KM3-Delay disconnection time relay; KM4-Power relay; XT1-Solenoid valve; M1-Motor; DY0-Photoelectric sensor power supply; FU1-Signal light fuse; LED1-Shaking signal light; FU2-Motor fuse. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0019] Those skilled in the art should connect all electrical components and their compatible power supplies in this case via wires, and should select appropriate controllers according to actual conditions to meet control requirements. The specific connection and control sequence should refer to the working principle described below, where the electrical components are connected in sequence. The detailed connection methods are well-known in the art. The following mainly introduces the working principle and process, without explaining the electrical control.

[0020] Please see Figures 2-5This case concerns the control circuit of an automatically braking snow sander. The control circuit includes a motor drive circuit and two detection circuits (left and right) for detecting the left or right deviation of the snow sander belt 1. These detection circuits are a left detection circuit and a right detection circuit, respectively. The left and right detection circuits have identical circuit structures, and the left detection circuit, right detection circuit, and motor drive circuit are connected in series. Each detection circuit includes a photoelectric sensor DY1 that detects the left or right deviation of the snow sander belt 1, a signal amplifier that receives the control signal from the photoelectric sensor DY1, an anti-jitter delay processing circuit to prevent signal jitter, a motor drive circuit controlled by the anti-jitter delay processing circuit, and a sander belt reset mechanism to reset the deviated snow sander belt 1. The photoelectric sensor DY1, signal amplifier, and anti-jitter delay processing circuit are connected in series before being connected to the motor drive circuit. The sander belt reset mechanism is connected to the sander belt reset output terminal of the signal amplifier.

[0021] Please see Figures 4-5 As a further preferred embodiment, the signal amplifier is a low-power relay KM2. The output signal terminal of the photoelectric sensor DY1 is electrically connected to the coil of the low-power relay KM2, and the first normally open contact KM2-1 of the low-power relay KM2 is the output terminal and electrically connected to the signal amplifier. That is, the output signal terminal of the photoelectric sensor DY1 drives the low-power relay KM2; after the low-power relay KM2 is energized, its normally closed contact KM2-1 is in the open state. Figure 5 In the middle, connected in series with the photoelectric sensor DY1 is the photoelectric sensor power supply DY0, which supplies power to the photoelectric sensor DY1.

[0022] Please see Figures 4-5 As a further preferred solution, the anti-jitter delay processing circuit is a delayed-off time relay KM3 with a delayed-off contact. The coil of the delayed-off time relay KM3 is electrically connected to the first normally open contact KM2-1 of the low-power relay KM2. One end of the normally open contact KM2-1 of the low-power relay KM2 is connected to the drive power supply of the delayed-off time relay KM3, and the other end is electrically connected to the coil of the delayed-off time relay KM3. After the delayed-off time relay KM3 is energized, its normally closed contact KM3-1 is open after the set delay time. The delayed-off time relay KM3 is equipped with a delay time adjustment component, which can generally be purchased as a standard part on the market. The delay time is generally set to 1~5 seconds.

[0023] Please see Figures 4-5 As a further preferred option, the motor drive circuit uses a power relay KM4 with a higher power rating than the low-power relay KM2. The normally closed contact KM4-A1 of the power relay KM4 is electrically connected to the motor M1 it drives. The power capacity of the normally closed contact KM4-A1 of the power relay KM4 should be matched with that of the motor M1 it drives. Figure 5In the diagram, normally closed contact KM4-A1 represents the normally closed contact of the left power relay KM4 in the left and right circuits; normally closed contact KM4-B1 represents the normally closed contact of the right power relay KM4 in the left and right circuits. Since the normally closed contacts of the power relays KM4 in both circuits control the same motor M1, they can be connected in series.

[0024] Please see Figures 4-5 As a further preferred option, a start-stop electrical module is connected in series between the motor drive circuit and the motor M1. The start-stop electrical module includes a start button SB1, a stop button SB2, and a self-locking intermediate relay KM1. The coils of the stop button SB2, the start button SB1, and the self-locking intermediate relay KM1 are connected in series. One normally open contact KM1-1 of the self-locking intermediate relay KM1 is connected in parallel across the start button SB1. The non-connected end of the stop button SB2 is electrically connected to the normally closed contact KM4-A1 of the power relay KM4. The coil of the self-locking intermediate relay KM1 is electrically connected to the N pole of the power supply. The motor M1 is electrically connected to the power supply through the normally open contact KM1-2 of the power relay KM4. Figure 5 In the middle, the motor fuse FU2 is connected in series with the motor M1.

[0025] Please see Figures 4-5 As a further preferred option, the low-power relay KM2 is provided with at least two sets of normally open contacts. The sanding belt reset mechanism includes an air gun 5 that can blow the deviated snowflake sanding belt 1 back to its original position and a solenoid valve XT1 that controls the opening and closing of the air gun 5. The solenoid valve XT1 is electrically connected to the output terminal of the first normally open contact KM2-2 of the low-power relay KM2.

[0026] Please see Figures 4-5 As a further preferred embodiment, the control circuit also includes a shaking indicator LED1 that indicates the working status of the snowflake sander belt 1. The shaking indicator LED1 is electrically connected to the output terminal of the third normally open contact KM2-3 of the low-power relay KM2. Figure 5 In the middle, the signal light fuse FU1 is connected in series with the shaking signal light LED1. When the shaking signal light LED1 flashes, it is in normal condition, or when it is off, it is in normal condition. When the shaking signal light LED1 is constantly lit, it is a warning signal, indicating that the snow sander is in the "brake" state.

[0027] It should be noted that the second normally open contact KM2-2 and the third normally open contact KM2-3 of the low-power relay KM2 can be combined into one normally open contact. The two normally open contacts are separated for ease of explanation.

[0028] The specific working process is as follows: First, install the photoelectric sensor DY1 on the snow sander, matching the left and right edges of the snow sander belt 1 so that the left and right edges of the snow sander belt 1 do not obstruct the photoelectric sensor DY1; when the snow sander belt 1 is in operation, whether it shifts to the left or right, the photoelectric sensor DY1 will be obstructed, and the photoelectric sensor DY1 will output a drive signal, driving the low-power relay KM2, which acts as a signal amplifier, to operate. At this time, the low-power relay KM2 outputs two signals through its normally open contacts: First signal: The second normally open contact KM2-2 and the third normally open contact KM2-3 of the low-power relay KM2 close, the shaking indicator LED1 and the solenoid valve XT1 are energized, the air gun 5 connected to the air source blows high-pressure air at the snow sand belt 1 to blow the deviated snow sand belt 1 back to its normal position. At this time, the left and right edges of the snow sand belt 1 are no longer blocking the photoelectric sensor DY1, the low-power relay KM2 is de-energized, the second normally open contact KM2-2 of the low-power relay KM2 opens, the solenoid valve XT1 is de-energized, and the air gun 5 closes to form a feedback closed loop; at the same time, the third normally open contact KM2-3 of the low-power relay KM2 closes, and the shaking indicator LED1 lights up; The second signal: The first normally open contact KM2-1 of the low-power relay KM2 closes, energizing the coil of the delayed disconnection time relay KM3, which serves as the anti-jitter delay processing circuit. Since the normally closed contact KM3-1 of the delayed disconnection time relay KM3 has a delayed disconnection effect, and this delayed disconnection can be adjusted and set on the delayed disconnection time relay KM3, it achieves signal anti-jitter action, preventing frequent starts and stops of motor M1 caused by normal short-term offsets. At this time, the delayed disconnection time relay KM3 has two options: First, if the delay time has not elapsed and the snowflake sand belt 1 returns to its normal position, the photoelectric sensor DY1 withdraws the offset signal, the low-power relay KM2 loses power, and the normally closed contact KM3-1 of the delayed disconnection time relay KM3 closes again, without affecting the normal operation of the motor M1. Secondly, if the delay time expires and the low-power relay KM2 is not de-energized, the normally closed contact KM3-1 of the delayed disconnection time relay KM3 will open, the coil of the power relay KM4 will be de-energized, the normally closed contact KM4-A1 of the power relay KM4 will open, and the motor M1 will stop, thus achieving a "braking" effect, stopping the snowflake sander belt 1, and causing the vibration indicator LED1 to remain lit as a warning. At this time, the staff can reset the snowflake sander belt 1 to prevent it from shifting a larger distance, avoid accidental detachment that could damage the grinding head and other components, and also avoid affecting the quality of the product being polished.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A control circuit for a snow sander with automatic braking, characterized in that... The control circuit includes a motor drive circuit and two detection circuits for detecting the left or right deviation of the snowflake sanding belt. These detection circuits are a left detection circuit and a right detection circuit, respectively. The left and right detection circuits have the same circuit structure, and the left detection circuit, the right detection circuit, and the motor drive circuit are connected in series. Each detection circuit includes a photoelectric sensor for detecting the left or right deviation of the snowflake sanding belt, a signal amplifier for receiving the control signal from the photoelectric sensor, a jitter-preventing delay processing circuit, a motor drive circuit controlled by the jitter-preventing delay processing circuit, and a sanding belt reset mechanism for resetting the deviated snowflake sanding belt. The photoelectric sensor, the signal amplifier, and the jitter-preventing delay processing circuit are connected in series before being connected to the motor drive circuit. The sanding belt reset mechanism is connected to the sanding belt reset output terminal of the signal amplifier.

2. The control circuit of the snow sander with automatic braking according to claim 1, characterized in that, The signal amplifier is a low-power relay. The output signal terminal of the photocell is electrically connected to the coil of the low-power relay, and the first normally open contact of the low-power relay is the output terminal and electrically connected to the signal amplifier.

3. The control circuit of the snow sander with automatic braking according to claim 2, characterized in that, The anti-jitter delay processing circuit is a delayed disconnection time relay with a delayed disconnection contact. The coil of the delayed disconnection time relay is electrically connected to the first normally open contact of the low-power relay.

4. The control circuit of the snow sander with automatic braking according to claim 3, characterized in that, The motor drive circuit is a power relay with a higher power rating than the low-power relay, and the normally closed contacts of the power relay are electrically connected to the motor it drives.

5. The control circuit of the snow sander with automatic braking according to claim 4, characterized in that, A start / stop electrical module is connected in series between the motor drive circuit and the motor. The start / stop electrical module includes a start button, a stop button, and a self-locking intermediate relay. The coils of the stop button, start button, and self-locking intermediate relay are connected in series in sequence. One normally open contact of the self-locking intermediate relay is connected in parallel across the start button. The non-connected end of the stop button is electrically connected to the normally closed contact of the power relay. The coil of the self-locking intermediate relay is electrically connected to the N pole of the power supply. The motor is electrically connected to the power supply through the normally open contact of the power relay.

6. The control circuit of the snow sander with automatic braking according to claim 5, characterized in that, The sanding belt reset mechanism includes an air spray gun that can blow the deviated snowflake sanding belt back to its original position and a solenoid valve that controls the opening and closing of the air spray gun. The solenoid valve is electrically connected to the output terminal of the second normally open contact of a low-power relay.

7. The control circuit of the snow sander with automatic braking according to claim 6, characterized in that, The control circuit also includes a vibration indicator light that indicates the working status of the snowflake sander belt. The vibration indicator light is electrically connected to the third normally open contact output terminal of the low-power relay.

Images