CN1108205C - Electromagnetic rivetter - Google Patents

Abstract

The present invention relates to an electromagnetic riveting device. In order to solve the problems of small capacitance, high riveting voltage, high loading speed rate, unreliable riveting quality, inconvenient operation and high riveting cost exist in the existing similar device, a plurality of pulse capacitors with the normal voltage of 3 to 5 kilovolt and a power supply system of the present invention are connected in parallel, an operating circuit is controlled by a programmable controller, the voltage is display with digital in real time, the monitoring protection of excess current, excess voltage, excess charge and electric leakage and the double shock absorption in a rivetter are added to a control system, the capacitance of the present invention is enlarged, and the loading speed rate, the riveting blowback and the riveting noise are reduced. The present invention has the advantages of high riveting quality, low cost and convenient operation.

Description

An electromagnetic riveting device

(1) Technical field:

The electromagnetic riveting equipment involved in the present invention is mainly used for riveting rivets of various materials in aviation, aerospace, automobile and bridge engineering, and is suitable for riveting rivets of difficult-to-form materials and large-diameter rivets.

(two) background technology:

In the manufacture of aviation and aerospace engineering products, a large number of rivets of various materials need to be riveted. Traditional riveting methods are:

The hammer riveting method using compressed air as the power source is more commonly used. However, this riveting method produces large recoil and noise, poor working conditions, and workers are prone to fatigue. The quality of riveting is affected by human factors, and the recoil generated when riveting large-diameter rivets is difficult for workers to bear.

The pressure riveting method with hydraulic pressure as the power source. The static pressure method is used to deform the rivet, and the riveting quality is relatively stable. However, the general riveting machine is relatively heavy and cannot be used for riveting in closed parts, nor can it be easily moved in the workshop; while the portable riveting machine is mainly used for riveting of small-diameter rivets, the requirement for the openness of the structure is also high. Widespread application of this method has been affected. The above common riveting method can generally only be used for riveting rivets of common materials, and is not suitable for riveting rivets of hard-to-form materials such as titanium alloys.

Another shortcoming of the common riveting method is that the expansion of the rivet shank is not uniform during riveting, and it is difficult to achieve interference along the entire shank for thick sandwich structures, and the fatigue life of the joint is low. When hammer riveting is used, the structure will be affected by impact force, so it is not suitable for riveting of composite materials.

In engineering practice, heating riveting is sometimes used for riveting rivets of difficult-to-form materials. This riveting method has low efficiency and high cost. In order to avoid the difficulties encountered when riveting large-diameter rivets, sometimes screw connections have to be used instead of riveting in the design, which increases the structural weight and reduces the connection efficiency.

(3) Contents of the invention:

In order to solve the problems existing in ordinary riveting methods, the United States invented stress wave riveting methods and equipment (US Patent: 3961739, May 7, 1974) and strong impact portable electromagnetic riveting equipment (US Patent: 3559269, December 1971 2nd). The basic ideas of these two patents are the same, both convert electrical energy into mechanical energy through capacitors and primary coils to complete the deformation of the rivets. The capacitor is first charged to store energy, and then the capacitor discharges the primary coil in the riveting gun. At the moment of discharge, the two coils in the riveting gun generate a strong repulsive force, which is transmitted to the rivet to complete the riveting. The devices invented by these two patents all use a high voltage of up to 10,000 volts. The capacitance of the device is small, and the loading rate during riveting is high. Microcracks are prone to appear in the heading of some rivets. In addition, the coil used in the equipment is difficult to manufacture, with high cost and short life. In order to solve the problems existing in high-voltage electromagnetic riveting or stress wave riveting, the United States invented the electromagnetic pulse driver (European patent: 0293257, May 27, 1988). This riveting equipment uses electrolytic capacitors, which increases the capacitance of the equipment and reduces the riveting voltage (the riveting voltage is generally below 500 volts), thereby reducing the loading rate and improving the riveting quality. However, electrolytic capacitors are not very suitable for the working conditions of pulse discharge, so the service life is limited, and the capacitor needs to be replaced after a certain period of use, which naturally increases the cost of riveting.

In order to overcome the problems existing in the prior art such as high voltage of riveting equipment, poor safety and reliability of equipment, difficulty in guaranteeing riveting quality and high riveting cost, the present invention proposes a new electromagnetic riveting equipment.

In order to realize the purpose of the present invention, this new electromagnetic riveting equipment adopts the following technical solutions.

1. The power supply system of the equipment uses a pulse capacitor with a rated voltage of 3000-5000V, and the common voltage is about 2000V. Using multiple capacitors in parallel increases the capacitance of the equipment, thereby reducing the loading rate of the equipment and improving the riveting quality.

2. In order to improve the anti-interference ability of the power supply system and the reliability of the equipment, the operation circuit is controlled by a programmable controller. The potentiometer is used to set the riveting voltage and the analog meter is used for synchronous digital display, and the actual voltage of the capacitor is displayed by a high-voltage digital meter, which improves the convenience of equipment use.

3. The riveting gun adopts double layers of vibration-damping pads and springs to reduce vibration, and a mass block is added between the vibration-damping layers to reduce the recoil and riveting noise generated during riveting.

4. The traditional coil has been improved. The primary coil used in the present invention solves the life and quality problems of the coil from the connection mode and coil structure: the copper strip is fixedly connected to the inner joint and the outer joint respectively, and the two outer joints are fixed on the coil shell.

5. Charging voltage control Through the PI control mode of the voltage loop, the real-time supplement of the voltage is realized, which avoids the voltage drop of the capacitor caused by the working current of the sensor, and ensures the stability of the riveting force. Protection functions such as overcurrent, overvoltage, overcharge, and leakage monitoring have been added to the control system.

6. The dialogue function is provided through the indicator lights of different colors between the riveting gun and the top iron, which improves the engineering practicability of the equipment.

7. The coil is cooled by compressed air, and the heat dissipation method is simple and practical, which solves the problem that the working stability of the coil is affected by the high working temperature.

Since the power supply system of the present invention is connected in parallel with multiple pulse capacitors, the operation circuit is controlled by a programmable controller, and the voltage is displayed in real time. Protection functions such as overcurrent, overvoltage, overcharge, and leakage monitoring have been added to the control system, and protection functions such as overcurrent, overvoltage, overcharge, and leakage monitoring have been added to the control system. The method of vibration-damping pad and double-layer spring damping increases the capacitance of the equipment, reduces the loading rate, reduces the recoil and noise during riveting, and improves the convenience of equipment use and riveting quality. The adoption of the new coil solves the quality problem of the key components of the electromagnetic riveting equipment, and further improves the engineering degree of the equipment. The use of pulse capacitors solves the problem of short life of electrolytic capacitors when they are used for pulse discharge, and reduces the cost of riveting.

(4) Description of drawings:

Accompanying drawing 1 is the schematic diagram of electromagnetic riveting equipment;

Accompanying drawing 2 is the structural diagram of electromagnetic riveting gun;

Accompanying drawing 3 is top iron structural diagram;

Accompanying drawing 4 is a coil structure diagram.

(5) Specific implementation methods;

Embodiment one

Electromagnetic riveting equipment is mainly composed of power supply system, riveting gun and top iron. The implementation process is described in detail below.

The power supply system uses 4 pulse capacitors with a rated voltage of 4000V and a rated capacity of 400 microfarads. The control system is mainly composed of two parts: analog control part and PLC operation loop control. The analog control mainly includes charging voltage control, thyristor trigger control and protection part. The charging voltage is controlled by the PI control method of the voltage loop to realize the real-time supplement of the voltage and avoid the voltage drop of the capacitor caused by the working current of the Hall sensor. Charging control includes two parts: voltage real-time measurement and voltage comparison. When the voltage of the measured capacitor is lower than the set voltage, the charging signal is input to the thyristor to continue charging; when the voltage reaches the set value, charging is stopped. Thyristor trigger control adopts TCA785 chip of SIEMENS company. The protection part mainly includes overcurrent, overvoltage, overcharge, leakage and other fault control. When overcurrent, overvoltage, overcharge or leakage occurs, the corresponding alarm signal will be output to the panel to display the fault status, and at the same time, the main circuit breaker will be disconnected. Contactor, bell alarm.

In order to improve the anti-interference ability of the power supply system and the reliability of the equipment, the operation circuit adopts the programmable controller LOGO124L of SIEMENS Company, which has 12 input terminals and 8 output terminals. The riveting voltage is set by a potentiometer and displayed digitally, and the actual voltage of the capacitor is displayed by a high-voltage digital meter.

The riveting gun mainly includes a housing 18, a front cover 14, a rear cover 19, a handle 1, a damping system (including a mass 5, a damping spring 20, a damping pad 6), a primary coil 7, a secondary coil 9, Modulator 10 and dialogue indicator light 8. The riveting gun adopts double-layer vibration reduction, the first layer adopts two layers of JD3 vibration-damping pads 6, the second layer uses spring vibration-damping pads 20, and a mass block made of 45# steel is added between the vibration-damping pads 6 and the vibration-damping springs 20 5. The handle 1 is connected to the rear cover 19 through bolts 21 , and the damping spring 20 is installed between the handle 1 and the housing 18 . The damping pad 6 and the mass block 5 are placed in the riveting gun housing 18 . There are three indicator lights on the riveting gun, yellow, red and green, respectively indicating the three states of "charging", "charging to" and "ready". Modulator 10 and secondary coil 9 are connected by screws 12 . Compressed air enters the interior of the riveting gun through the air inlet 15 to cool the primary coil 7 . The modulator 10, the secondary coil 9, the primary coil 7 and the damping system are respectively loaded into the riveting gun housing 18, and the riveting gun housing 18 is made of nylon with good insulation performance. The external connection joints 25 and 28 of the primary coil are connected to the external power line through the bolt 16, and the external power line is fixed by the pressing block 17. The front cover 14 , the rear cover 19 and the housing 18 are connected as a whole through the connecting rod 13 .

The primary coil [7] has an outer diameter of 100 mm, is wound with a copper strip with a width of 25 mm and a thickness of 1 mm, and the coil has 30 turns in total. It consists of a resin insulating layer 22, a top tight block 23, an insulating plate 24, external connecting joints 25 and 28, copper strips 26 and 27 and an internal connecting joint 31. Coil turns are insulated with resin and glass cloth; the inner connection joint 31 is a copper tube with threads inside, and one end of the copper strip 26 and the inner connection joint 31 are welded together by brazing, and are connected by screws 30 and copper strip 26 And 27 are welded with outer connecting joint 28. The secondary coil 9 is a 6mm copper plate. In order to ensure safe and reliable use, the primary coil casing 29 is made of nylon with good insulation performance and high strength. The two outer connection joints 25 and 28 of the coil are fixed on the nylon shell by the tight block 23 .

Top iron is made up of handle 32, trigger 33, indicator light 34, damping pad 35, top iron core 36, shell 37, conical head 38, rivet clip 39, the handle 32 of top iron, shell 37 and conical head 38 are used Made of nylon material. Handle 32 and shell [37] and conical head 38 are connected by thread, and rivet clip 39 is positioned at the front end of top iron core by transition fit, and it can be replaced as required. Top iron core 36 is made of 45# steel. The two indicator lights 34, yellow and red, represent two states of "charging" and "charging to" respectively.

When this equipment is riveting 4mm steel rivets, the riveting voltage is about 2300V, the charging time is 4 seconds, and the half-wave period of the discharge current is about 800 microseconds. The riveting noise is up to 96 decibels, and the recoil force is two orders of magnitude smaller than the riveting force, about 40-50kg.

According to the EMR-4-12 electromagnetic riveting equipment developed by the present invention, the maximum stored energy is 12KJ, the maximum riveting voltage is 4000V, the common voltage is about 2000V, the input power is two-phase 380V or single-phase 220V, and the charging and discharging frequency is not less than 8 times/ minute. The equipment can rivet rivets of hard-to-form materials such as steel rivets below 6mm, titanium alloys and high-temperature alloys. For thick sandwich structures, a certain amount of interference can be achieved along the entire shank.

Embodiment two

Electromagnetic riveting equipment is mainly composed of power supply system, riveting gun and top iron. The implementation process is described in detail below.

The power supply system uses 6 pulse capacitors with a rated voltage of 4000V and a rated capacity of 400 microfarads. The control system is mainly composed of two parts: analog control part and PLC operation loop control. The analog control mainly includes charging voltage control, thyristor trigger control and protection part. The charging voltage is controlled by the PI control method of the voltage loop to realize the real-time supplement of the voltage and avoid the voltage drop of the capacitor caused by the working current of the Hall sensor. Charging control includes two parts: voltage real-time measurement and voltage comparison. When the voltage of the measured capacitor is lower than the set voltage, the charging signal is input to the thyristor to continue charging; when the voltage reaches the set value, charging is stopped. Thyristor trigger control adopts TCA785 chip of SIEMENS company. The protection part mainly includes overcurrent, overvoltage, overcharge, leakage and other fault control. When over-current, over-voltage, over-charge or leakage occurs, the corresponding alarm signal will be output to the panel and display the fault status, and the main contactor will be disconnected at the same time, and the bell will sound an alarm.

In order to improve the anti-interference ability of the power supply system and the reliability of the equipment, the operation circuit adopts the programmable controller LOGO124L of SIEMENS Company, which has 12 input terminals and 8 output terminals. The riveting voltage is set by a potentiometer and displayed digitally, and the actual voltage of the capacitor is displayed by a high-voltage digital meter.

The riveting gun mainly includes a housing 18, a front cover 14, a rear cover 19, a handle 1, a damping system (including a mass 5, a damping spring 20, a damping pad 6), a primary coil 7, a secondary coil 9, Modulator 10 and dialogue indicator light 8. The riveting gun adopts double-layer vibration reduction, the first layer uses two layers of JD3 vibration-damping pads 6, the second layer uses spring vibration-damping 20, and a mass block made of 45# steel is added between the vibration-damping pads 6 and the vibration-damping springs 20 5. The handle 1 is connected to the rear cover 19 through bolts 21 , and the damping spring 20 is installed between the handle 1 and the housing 18 . The damping pad 6 and the mass block 5 are placed in the riveting gun housing 18 . There are three indicator lights on the riveting gun, yellow, red and green, respectively indicating the three states of "charging", "charging to" and "ready". Modulator 10 and secondary coil 9 are connected by screws 12 . Compressed air enters the interior of the riveting gun through the air inlet 15 to cool the primary coil 7 . The modulator 10, the secondary coil 9, the primary coil 7 and the damping system are respectively loaded into the riveting gun housing 18, and the riveting gun housing 18 is made of nylon with good insulation performance. The external connection joints 25 and 28 of the primary coil are connected to the external power line through the bolt 16, and the external power line is fixed by the pressing block 17. The front cover 14 , the rear cover 19 and the housing 18 are connected as a whole through the connecting rod 13 .

The primary coil [7] has an outer diameter of 150 mm, is wound with a copper strip with a width of 25 mm and a thickness of 1 mm, and the coil has 44 turns in total. It consists of a resin insulating layer 22, a top tight block 23, an insulating plate 24, external connecting joints 25 and 28, copper strips 26 and 27 and an internal connecting joint 31. Coil turns are insulated with resin and glass cloth; the inner connection joint 31 is a copper tube with threads inside, and one end of the copper strip 26 and the inner connection joint 31 are welded together by brazing, and are connected by screws 30 and copper strips 27 And 26 are welded with outer connecting joint 28. The secondary coil 9 is a 6mm copper plate. In order to ensure safe and reliable use, the primary coil casing 29 is made of nylon with good insulation performance and high strength. The two outer connection joints 25 and 28 of the coil are fixed on the nylon shell by the tight block 23 .

Top iron is made up of handle 32, trigger 33, indicator light 34, damping pad 35, top iron core 36, shell 37, conical head 38, rivet clip 39, the handle 32 of top iron, shell 37 and conical head 38 are used Made of nylon. The handle 32 is connected with the shell 37 and the conical head 38 by threads, and the rivet 39 is positioned with the front end of the top iron core through a transition fit, and can be replaced according to different rivets. Top iron core 36 is made of No. 45 steel. The two yellow and red indicator lights 34 represent two states of "charging" and "charging to" respectively. The EMR-4-19 electromagnetic riveting equipment developed according to the present invention has a maximum stored energy of 19KJ, a maximum riveting voltage of 4000V, a two-phase 380V input power supply, and a charging and discharging frequency of not less than 6 times per minute. The equipment can rivet rivets of hard-to-form materials such as steel rivets below 8mm, titanium alloys and high-temperature alloys.

When the equipment is riveting a 6mm steel rivet, the riveting voltage is about 2600V, the charging time is 5 seconds, and the half-wave period of the discharging current is about 1200 microseconds. Riveting noise up to 99 decibels.

Claims (6)

1. An electromagnetic riveting device, mainly composed of a power supply, an electromagnetic riveting gun and a top iron, is characterized in that: a. The power supply system of the equipment adopts a pulse capacitor with a rated voltage of 3000-5000 volts, and the operating circuit adopts PLC control; b. The riveting gun adopts double-layer vibration reduction; c. The charging voltage control adopts the PI control mode of the voltage loop. 2. The electromagnetic riveting device according to claim 1, characterized in that the electromagnetic riveting gun includes a handle, a damping system, a primary coil, a modulator, and: a. The shell of the electromagnetic riveting gun is made of nylon material; b. Cool the coil with compressed air; c. A mass block is added between the damping layers. 3. Electromagnetic riveting equipment as claimed in claim 2, characterized in that the copper strip (26) of the primary coil is fixedly connected with the inner connection joint (31) and the outer connection joint (25), (28) respectively, and the outer connection joint (25), (28) are fixed on the coil casing (29). 4. The electromagnetic riveting equipment according to claim 1, characterized in that the riveting voltage is set by a potentiometer, the digital display is synchronized by an analog meter, and the actual voltage of the capacitor is displayed by a high-voltage digital meter. 5. The electromagnetic riveting device as claimed in claim 1, characterized in that an indicator light is used to realize dialogue between the riveting gun and the top iron. 6. Electromagnetic riveting equipment as claimed in claim 3, it is characterized in that the coil external connection joint (25) and (28) of the primary coil in the electromagnetic riveting gun are connected by bolt (16) and external wire; Inner joint (31) is The copper pipe has threads inside; the primary coil shell (29) is nylon material.

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