CN112453961A

CN112453961A - Automatic flat tongs and control method thereof

Info

Publication number: CN112453961A
Application number: CN202011345404.6A
Authority: CN
Inventors: 郑万兴; 郭小芳; 吴丽萍
Original assignee: Foshan City Gaoming District Senior Technical School
Current assignee: Foshan City Gaoming District Senior Technical School
Priority date: 2020-11-26
Filing date: 2020-11-26
Publication date: 2021-03-09

Abstract

The invention discloses an automatic flat tongs and a control method thereof, wherein the flat tongs comprises a base body, and a fixed tong and a movable tong which are arranged on the base body, the fixed tong is arranged at one end of the base body, a guide rail is arranged on the base body, the movable tong is sleeved on the guide rail, the other end of the base body is provided with a driving mechanism, the output end of the driving mechanism is connected with a screw rod, the movable tong is provided with a threaded through hole, the other end of the screw rod penetrates through the threaded through hole of the movable tong and is connected with the fixed tong, and one surface of the fixed tong facing the movable tong is provided with a pressure sensor; the flat-nose pliers are further provided with a control mechanism, and the control mechanism is electrically connected with the driving mechanism and the pressure sensor respectively. The automatic flat tongs provided by the invention can realize automatic disassembly and assembly of workpieces, not only saves labor, but also can clamp the workpieces more stably, can detect the pressure applied to the workpieces, controls the driving mechanism according to the pressure, improves the clamping stability of the workpieces and improves the machining precision.

Description

Automatic flat tongs and control method thereof

Technical Field

The invention relates to the technical field of clamps, in particular to automatic flat tongs and a control method thereof.

Background

A flat tongs also known as a machine vice is a general clamp, is usually used for fixing small-sized workpieces, is a random clamp of a milling machine, a drilling machine and a planer, is generally fixed on a machine tool workbench and is used for clamping the workpieces to carry out various machining. The existing flat tongs comprise a fixed tong and a movable tong, the workpiece is disassembled and assembled by adjusting the distance from the movable tong to the fixed tong, and during specific operation, the movable tong is usually adjusted manually by a wrench, so that the defects of high labor intensity (particularly, the workpiece is disassembled and assembled by frequently using the flat tongs for a long time), low working efficiency, inconvenient operation, low speed and the like exist. In the prior art, a driving motor is additionally arranged on a movable clamp or a fixed clamp of a flat-nose clamp, and the movable clamp moves back and forth by driving of a driving mechanism to realize the dismounting of a workpiece. However, in the existing method for controlling the motor through the driving mechanism, the output end of the driving mechanism is usually directly connected with the movable clamp through a screw rod or a screw rod, but the movable clamp is connected on the guide rail in a sliding manner, so that the defect that the machining precision is reduced due to unstable fixation of the movable clamp in the machining process of a workpiece is easily caused. In addition, the clamping stability of the movable clamp and the fixed clamp on the workpiece is related to the force applied by the movable clamp and the fixed clamp on the workpiece, the clamping is unstable due to small clamping force, the workpiece is easy to deform due to too large clamping force, and the clamping force of the fixed clamp and the movable clamp cannot be accurately controlled by the conventional flat tongs. It is seen that improvements and enhancements to the prior art are needed.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide an automatic flat-nose pliers and a control method thereof, aiming at improving the automation degree and the clamping stability of the flat-nose pliers for clamping workpieces.

In order to achieve the purpose, the invention adopts the following technical scheme:

an automatic flat-nose pliers comprises a base body, a fixed pliers and a movable pliers, wherein the fixed pliers and the movable pliers are arranged on the base body, the fixed pliers are arranged at one end of the base body, a guide rail is arranged on the base body, the movable pliers are sleeved on the guide rail, a driving mechanism is arranged at the other end of the base body, the output end of the driving mechanism is connected with a lead screw, the movable pliers are provided with threaded through holes, the other end of the lead screw penetrates through the threaded through holes of the movable pliers and is connected with the fixed pliers, and one surface of the fixed pliers, facing the movable pliers, is provided with a pressure sensor; the flat-nose pliers are further provided with a control mechanism, and the control mechanism is electrically connected with the driving mechanism and the pressure sensor respectively.

In the automatic flat-nose pliers, the guide rail comprises a main guide groove arranged in the middle of the base body and auxiliary guide grooves arranged on two sides of the main guide groove, a lug matched with the guide rail is arranged on the bottom surface of the movable pliers, the lug comprises a main lug arranged in the middle and auxiliary lugs arranged on two sides of the main lug, and the main lug is provided with a threaded through hole.

In the automatic flat tongs, two inner side walls of the main guide groove and the auxiliary guide groove are provided with limiting guide grooves, and two sides of the main lug and the auxiliary lug are provided with corresponding bulges.

In the automatic flat tongs, the driving mechanism is a servo motor or a stepping motor.

In the automatic flat tongs, the control mechanism comprises a circuit protection module.

In the automatic flat-nose pliers, one end of the base body, which is opposite to the fixed pliers, is provided with an infrared sensor, and the infrared sensor is electrically connected with the control mechanism and used for detecting the position of the movable pliers.

In the automatic flat tongs, a buffer layer is arranged on one side, opposite to the fixed tongs and the movable tongs, of the fixed tongs, and the buffer layer is made of elastic materials.

In the automatic flat tongs, the elastic material comprises one of rubber, silica gel or plastics.

A method for controlling an automated flat-nose pliers, wherein the method employs the automated flat-nose pliers as described above, the method comprising the steps of:

s1, setting a pressure limit value and a position limit value through a control mechanism;

s2, placing a workpiece close to a fixed clamp, starting a switch, driving a movable clamp to move towards the fixed clamp by a driving mechanism until the movable clamp is close to the workpiece, detecting the pressure applied to the fixed clamp by a pressure sensor, feeding pressure information back to a control mechanism, stopping driving the driving mechanism when the pressure value reaches a set value, keeping the flat tongs in a clamping state, and assisting a numerical control machine tool to process;

and S3, when the numerical control machine tool finishes machining, starting the movable clamp to return to a command, reversely rotating the driving mechanism, enabling the movable clamp to move along the track in the direction away from the fixed clamp, stopping the driving mechanism when the movable clamp returns to the original position, unloading the workpiece, and finishing primary clamping.

In the method for controlling the automatic flat-nose pliers, in the step S3, when the movable pliers return, the method further includes infrared distance measurement, and when the infrared sensor detects that the position of the movable pliers is the set position, the control mechanism stops the driving mechanism.

Has the advantages that:

the invention provides an automatic flat tongs and a control method thereof, wherein the flat tongs can make a movable tong reciprocate on a guide rail by arranging a driving mechanism to realize automatic disassembly and assembly of workpieces; in addition, the pressure sensor arranged on the fixed clamp can detect the pressure applied to the workpiece, and the driving mechanism is controlled according to the pressure, so that the clamping stability of the workpiece is improved, and the workpiece deformation caused by overlarge clamping force is avoided. According to the control method of the automatic flat tongs, the clamping force of the braking tongs and the fixed tongs on the workpiece can be automatically controlled through the pressure sensor, manual operation is not needed, the automation degree is high, the workpiece is clamped stably, and therefore the machining precision of the workpiece is improved.

Drawings

Fig. 1 is a schematic structural diagram of an automated flat-nose pliers provided by the invention.

Fig. 2 is a schematic cross-sectional view of the base body and the movable clamp.

Fig. 3 is a schematic cross-sectional view of a base body provided with a limiting guide groove and a movable clamp provided with a protrusion.

Detailed Description

The invention provides an automatic flat tongs and a control method thereof, and in order to make the purpose, technical scheme and effect of the invention clearer and clearer, the invention is further described in detail by referring to the attached drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the embodiments of the present invention, it should be noted that the terms "disposed" and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; they may be mechanically coupled, directly coupled, indirectly coupled through intervening media, or may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1-3, the invention provides an automatic flat tongs, the flat tongs comprises a base body 1, a fixed tong 2 and a movable tong 3, the fixed tong 2 and the movable tong 3 are arranged on the base body, the base body 1 is fixedly connected to a numerical control machine tool, one end of the base body is a head end, the end opposite to the head end is a tail end, the fixed tong is arranged at the head end of the base body, the base body is provided with a guide rail, the movable tong is connected to the guide rail 18 in a sliding manner, the tail end of the base body is provided with a fixed frame 7, the fixed frame 7 is provided with a driving mechanism 4, the output end of the driving mechanism 4 is connected with a screw rod 9 through a coupler 8, the movable tong 3 is provided with a threaded through hole 15 in the same direction as the guide rail, and the other end of; the flat-nose pliers are further provided with a control mechanism, the driving mechanism is electrically connected with the control mechanism, and the control mechanism controls the driving mechanism to be switched on and off.

According to the flat-nose pliers with the structure, the two ends of the screw rod are connected to the fixed pliers and the driving mechanism, the movable pliers are arranged on the guide rail and sleeved on the screw rod, on one hand, the movable pliers can be controlled by the driving motor, automatic clamping of a workpiece is achieved, on the other hand, the movable pliers are clamped more stably, and the machining precision of public construction is improved. When the clamping device works, the driving mechanism drives the screw rod to rotate, the movable clamp is driven to slide towards the fixed clamp direction along the guide rail until the movable clamp is tightly attached to a workpiece, and when the clamping device can stably clamp the workpiece, the driving mechanism stops driving, and clamping and fixing of the workpiece before machining are completed.

Specifically, as shown in fig. 2, in the automatic flat tongs with the above structure, the guide rail 18 comprises a main guide groove 11 disposed at the middle part of the surface of the base body and auxiliary guide grooves 12 disposed at both sides of the main guide groove, the main guide groove 11 and the auxiliary guide groove 12 are both U-shaped grooves extending to both ends along the surface of the base body, the bottom surface of the movable clamp is provided with a convex block matched with the guide rail, the convex block comprises a main convex block 13 positioned in the middle of the bottom surface of the movable clamp, and auxiliary bumps 14 positioned at both sides of the main bump, the main bump 13 and the auxiliary bumps 14 forming an inverted chevron-shaped structure, and the sizes of the main lug 13 and the auxiliary lug 14 are matched with the sizes of the main guide groove 11 and the auxiliary guide groove 12, a threaded through hole 15 is arranged in the middle of the main lug 13, the screw rod 9 penetrates through the threaded through hole 15, one end of the screw rod is connected to the fixed clamp 2 arranged at the head end of the base body, and the other end of the screw rod is in transmission connection with the output end of the driving mechanism 4 through the coupler 8. When the automatic brake caliper works, the driving mechanism 4 drives the screw rod 9 to rotate, the screw rod 9 drives the movable caliper 3 to reciprocate along the guide rail, and the arranged main guide groove 11 and the auxiliary guide groove 12 can better limit the motion track of the caliper and enable the movable caliper to reciprocate only along the direction of the main guide groove 11. It should be noted that the threaded through hole 15 is located at a height lower than the surface of the base, i.e., the screw 9 is located at a horizontal position lower than the surface of the base, so that the upper surface of the screw does not contact the workpiece when the workpiece is clamped on the flat tongs.

Preferably, as shown in fig. 3, in the automatic flat tongs with the above structure, two inner side walls of the main guide groove are provided with limiting guide grooves 16, two sides of the main bump are provided with corresponding protrusions 17, when the automatic flat tongs are connected, the movable tongs 3 are sleeved on the base body from the end portion of the base body 1 along the main guide groove and the auxiliary guide groove, and the limiting guide grooves 16 can prevent the movable tongs from moving upwards under stress or vibration in the process of processing a workpiece, so that the clamping stability of the workpiece is improved, and the processing precision is further improved. Preferably, the groove wall of the auxiliary guide groove 12 is also provided with a limiting guide groove 16, and correspondingly, the two sides of the auxiliary projection 14 are also provided with protrusions 17 matched with the auxiliary guide groove, so that when the movable clamp is connected to the guide rail, the movable clamp can only reciprocate back and forth along the main guide groove and the auxiliary guide groove, especially when a workpiece is machined, the movable clamp and the fixed clamp can fix the workpiece more stably, and the machining precision of the workpiece is improved.

Preferably, as shown in fig. 1, in some embodiments, the fixed jaw 2 and the movable jaw 3 are provided with a buffer layer 10 on the opposite side, and the buffer layer is made of an elastic material, and the elastic material may be one of rubber, plastic or silicon rubber. The buffer layer 10 can improve the centre gripping steadiness of flat tongs to the work piece, reduces the wearing and tearing of moving tong and stationary tong to the work piece surface simultaneously, and in addition, the buffer layer can reduce the work piece in the course of working to the vibration of moving tong, reduces the inside wearing and tearing of device, improves the life of device.

Specifically, as shown in fig. 1, in the automatic flat-nose pliers with the above structure, a pressure sensor 5 is arranged on one surface of the fixed pliers facing the movable pliers, and the pressure sensor is electrically connected with the control mechanism. Because the clamping stability degree of the workpiece is related to the pressure exerted on the workpiece by the fixed clamp and the movable clamp during clamping, when the pressure is lower, the workpiece is not stably clamped and is easy to shift during processing, so that the processing precision is reduced; when the pressure is too high, although the clamping is stable, the workpiece is easy to deform, the machining precision is also reduced, the influence of the pressure with proper magnitude on the machining precision is very large, and the large pressure is usually applied under the condition that the workpiece is ensured not to deform, so that the workpiece is not subjected to the phenomenon of vibration and displacement during machining. In the specific implementation process, when a workpiece is clamped, the movable clamp applies proper pressure to the workpiece by controlling the feeding amount of the driving mechanism. The control mechanism receives the pressure information and compares the pressure information with a set pressure value, when the pressure value is greater than or equal to a set value, the driving mechanism stops working, and when the pressure value is less than the set value, the driving mechanism continues to drive the movable clamp to move towards the fixed clamp until the actual pressure is equal to the set pressure limit value.

Preferably, as shown in fig. 1, an infrared sensor 6 is further disposed on the tail end of the base body or a fixing frame 7 of the driving mechanism, and the infrared sensor 6 is electrically connected to the control mechanism and is used for detecting the distance from the movable clamp to the driving mechanism. The infrared sensor comprises an infrared transmitter and an infrared receiver, the infrared transmitter can transmit infrared rays to the movable clamp, when the infrared rays touch the movable clamp, the infrared rays can return to be received by the infrared receiver, the infrared receiver converts the infrared rays into electric signals according to the strength of the received infrared rays and sends the electric signals to the control mechanism, and the control mechanism judges the distance between the movable clamp and the tail end of the base body according to the received electric signals and serves as a basis for controlling the driving motor. When the specific implementation, when the work piece processing is accomplished, the movable clamp need loosen the work piece, just can take off the work piece from the flat-nose pliers, and concrete step is: the driving mechanism rotates reversely to enable the movable clamp to move towards the tail end of the base body along the guide rail, the returning distance of the movable clamp is controlled by the working time length of the driving mechanism, the arranged infrared sensor can measure the distance from the movable clamp to the driving mechanism or the end part of the base body and transmit the distance information to the control mechanism, the control mechanism can preset the distance value from the movable clamp to the tail end or the driving mechanism, the distance value is compared with a set value according to the obtained distance information, and if the distance value reaches the set position, the driving mechanism is closed, and the movable clamp stops moving. The infrared sensor that sets up can assist actuating mechanism to return to the assigned position with the pincers, makes the stroke range of pincers inject in setting for the within range, is convenient for take out of work piece and the centre gripping of next work piece, also avoids appearing the tail end that the pincers had arrived the base member, and actuating mechanism continues to rotate the phenomenon that appears transshipping or locked rotor.

Specifically, the automatic flat-nose pliers with the structure have the advantages that the driving mechanism is the servo motor or the stepping motor, the control precision of the servo motor and the stepping motor is high, and the clamping is stable.

Specifically, control mechanism includes PLC controller and relevant control circuit, the PLC controller passes through relevant control circuit and actuating mechanism, infrared sensor, pressure sensor electric connection for control actuating mechanism's operation and the pressure information of collecting when centre gripping and the position information when the pincers return, control mechanism is equipped with control panel, and accessible control panel sets for pressure limit value and position limit value, and starts and close actuating mechanism. When the clamping device works, a workpiece is placed close to the fixed clamp, then equipment is started, the motor is driven to work, the movable clamp moves towards the fixed clamp along the guide rail, when the movable clamp moves to be close to the workpiece, pressure information can be generated at the pressure sensor, the pressure sensor converts the pressure information into an electric signal and sends the electric signal to the control mechanism, the control mechanism is compared with a set value, and if the pressure information is equal to the set value, the driving mechanism stops moving, so that clamping is more stable under the condition that the workpiece is not damaged by clamping pressure; treat that the work piece processing is complete, assign the pincers through control panel and return the order, actuating mechanism antiport, drive lead screw antiport, make the pincers move toward the direction of keeping away from the fixed pincers along the guide rail, infrared sensor work this moment, to the infrared ray of moving pincers transmission, infrared ray touches and returns after moving pincers, received by infrared receiving device, infrared sensor is according to the change of infrared ray of infrared receipt, turn into the signal of telecommunication and send to control mechanism, control mechanism compares signal of telecommunication and the setting value of receiving, when the signal of telecommunication equals the setting value, stop actuating mechanism work, make the pincers be fixed in on the position that the base member set for.

Preferably, control mechanism still is equipped with short-circuit protection module, short-circuit protection module is used for protecting actuating mechanism and carries out short-circuit protection under stall, the overload condition, avoids when pressure limit value sets up too high, makes driving motor overload burn out the motor, perhaps leads to when the lead screw is blockked up by debris rotating unsmoothly, the phenomenon that actuating mechanism is by the stall appears, and the short-circuit protection module of setting can avoid actuating mechanism to burn out, extension actuating mechanism's life.

The invention also provides a control method of the automatic flat-nose pliers, which adopts the automatic flat-nose pliers, and comprises the following steps:

and S1, setting a pressure limit value and a position limit value through a control panel of a control mechanism. The pressure limit value is the pressure applied to the workpiece when the movable clamp and the fixed clamp the workpiece, the pressure applied to the workpiece is monitored in real time through a pressure sensor arranged on the fixed clamp by the automatic flat tongs and fed back to the control mechanism to serve as a basis for the control mechanism to control the work of the driving mechanism, the set pressure limit value is set according to the compression resistance of the workpiece and the vibration force applied to the workpiece during machining, the set pressure limit value must be larger than the vibration force generated during machining but smaller than the pressure value before deformation of the workpiece, and the pressure limit value of each type of workpiece can be measured through experiments. The position limit value is the position distance of the moving clamp which stays at last when the moving clamp moves towards the direction far away from the fixed clamp after the workpiece is machined, the position information of the moving clamp is monitored in real time through the arranged infrared sensor, and the position information of the moving clamp is fed back to the control mechanism to be used as the basis for the control mechanism to control the driving mechanism.

S2, placing a workpiece close to a fixed clamp, starting a switch, driving a movable clamp to move towards the fixed clamp by a driving mechanism until the movable clamp is close to the workpiece, detecting the pressure applied to the fixed clamp by a pressure sensor, feeding pressure information back to a control mechanism, continuing to work by the driving mechanism when the pressure information is less than a set pressure limit value, sending a command by the control mechanism when the pressure value reaches a set value, stopping the driving mechanism to work, keeping the flat tongs in a clamping state at the moment, and processing the workpiece by a numerical control machine tool;

s3, after the numerical control machine tool is machined, the workpiece needs to be unloaded, a movable clamp is started to return a command, the driving mechanism rotates reversely, the movable clamp moves along the track in the direction away from the fixed clamp, the infrared sensor works at the moment, the position of the movable clamp is monitored in real time, position information is generated and sent to the control mechanism, the control mechanism compares the position information with a set position limit value, when the movable clamp returns to the original position, the control mechanism issues a command of stopping the driving mechanism, the driving mechanism stops working, the movable clamp stops being unintelligible, the workpiece is unloaded, and one-time clamping is completed.

When the step S2-step S3 are performed, the short-circuit protection module monitors the operation condition of the motor at the same time, when the set pressure limit value is too high or a foreign object blocks the moving clamp on the guide rail, the driving mechanism may have an excessive current and power, and if the driving mechanism is not stopped, the motor is easily burned out, and the short-circuit protection module can start short-circuit protection for the driving mechanism when the driving mechanism has a large current or large power, so as to avoid the driving mechanism from being burned out.

It should be understood that equivalents and modifications of the technical solution and inventive concept thereof may occur to those skilled in the art, and all such modifications and alterations should fall within the scope of the appended claims.

Claims

1. An automatic flat-nose pliers comprises a base body, a fixed pliers and a movable pliers, wherein the fixed pliers and the movable pliers are arranged on the base body; the flat-nose pliers are further provided with a control mechanism, and the control mechanism is electrically connected with the driving mechanism and the pressure sensor respectively.

2. The automatic flat-nose pliers according to claim 1, wherein the guide rail comprises a main guide groove arranged in the middle of the base body and auxiliary guide grooves arranged on both sides of the main guide groove, the bottom surface of the movable pliers is provided with a projection matched with the guide rail, the projection comprises a main projection arranged in the middle and auxiliary projections arranged on both sides of the main projection, and the main projection is provided with a threaded through hole.

3. The automatic flat-nose pliers according to claim 2, wherein the two inner side walls of the main guide groove and the auxiliary guide groove are provided with limiting guide grooves, and the two sides of the main lug and the auxiliary lug are provided with corresponding bulges.

4. The automated flat-nose pliers according to claim 1, wherein the drive mechanism is a servo motor or a stepper motor.

5. The automated flat-nose pliers of claim 1, wherein the control mechanism comprises a circuit protection module.

6. The automatic flat-nose pliers according to claim 1, wherein an infrared sensor is disposed at an end of the base opposite to the fixed pliers, and the infrared sensor is electrically connected to the control mechanism for detecting the position of the movable pliers.

7. The automated flat-nose pliers according to claim 1, wherein a buffer layer is arranged on the side of the fixed pliers opposite to the movable pliers, and the buffer layer is made of an elastic material.

8. The automated flat-nose pliers of claim 7, wherein the resilient material comprises one of rubber, silicone, or plastic.

9. A method for controlling an automated flat-nose pliers, characterized in that it uses an automated flat-nose pliers according to any one of claims 1 to 8, said method comprising the steps of:

10. The method for controlling an automatic flat-nose pliers according to claim 9, wherein in step S3, when the movable pliers are returned, the method further comprises an infrared distance measurement, and when the infrared sensor detects that the position of the movable pliers is a set value, the control mechanism stops the operation of the driving mechanism.