CN106001902B - One kind squeezes into the adjustable filled type friction stir weld device of speed - Google Patents

Abstract

The invention discloses a filling type friction stir welding device with adjustable extrusion speed, which comprises a frame on which several linear motors are installed, and the linear motors are connected to a central shaft sleeve inside the frame through a connecting rod. , the central shaft sleeve is connected with the positioning cylinder through the first bearing, the positioning cylinder is sleeved on the central shaft and rotates synchronously with the central shaft, the lower end of the central shaft is fixedly connected with the guide block, the guide block is connected with several push rods, and the push rod One end is inserted into the filling hole of the upper shaft shoulder, and the filling hole is filled with welding materials; the upper shaft shoulder is fixedly connected with the rotating device, and the rotating device is connected with the machine head through the second bearing, and the machine head is fixed under the machine frame. The rotating device is provided with a guide hole, and the guide block moves up and down along the guide hole. The filling type friction stir welding device with adjustable extrusion speed of the present invention uses a linear motor to push the guide block to move, pushes the welding material into the strip welding head, and the force is uniform and moderate during the filling process.

Description

A filling type friction stir welding device with adjustable extrusion speed

technical field

The invention relates to a filling type friction stir welding device with adjustable extrusion speed, which belongs to the field of welding.

Background technique

Bobbin Tool Friction Stir Welding (BTFSW for short) is a welding technology derived from friction stir welding in recent years. In addition to the advantages of ordinary friction stir welding technology, double-shouldered friction stir welding can also weld hollow components with complex shapes; in addition, due to the high stiffness of the double-shouldered friction stir welding stirring head, it can withstand large welding loads Welding thicker workpieces has been successfully applied in aviation, aerospace, ships, trains, electric power and heavy weapons, etc. However, the current double-shaft friction stir welding is easy to be damaged due to the high-speed rotation and friction of the stirring needle and the upper and lower shoulders during the welding process. It causes flash, which leads to the lack of metal in the base metal and produces defects similar to holes and tunnels.

Previous patents only proposed to improve the welding process parameters, the size of the stirring head and the structure of the stirring needle to achieve more stability in the welding process, so as to reduce the flash as much as possible and avoid defects caused by metal loss. However, it does not The desired effect is not achieved, and its welding repeatability is poor; in addition, it is unavoidable to leave a huge V-shaped notch at the beginning and end of welding.

It can be seen that when using double-shaft shoulder friction stir welding, there are several problems: (1) the welding starting point and the key point have a V-shaped notch that can cause cracks; (2) part of the metal is lost due to flash extrusion during the welding process Cause holes and tunnels inside the weld; (3) The possibility of welding defects will increase significantly when welding large-scale workpieces, resulting in a limited range of non-use of this welding method. Therefore, a filling friction stir welding device with adjustable extrusion speed is proposed.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a filling friction stir welding device with adjustable extrusion speed, which uses a linear motor to push the guide block to move, pushes the welding material into the strip welding head, and fills The strength is even and moderate in the process.

Technical solution: In order to solve the above technical problems, a filling friction stir welding device with adjustable extrusion speed of the present invention includes a frame on which several linear motors are installed, and the linear motors are connected to the The central shaft sleeve in the frame is connected, the central shaft sleeve is connected with the positioning cylinder through the first bearing, the positioning cylinder is sleeved on the central shaft and rotates synchronously with the central shaft, the lower end of the central shaft is fixedly connected with the guide block, and the guide block and Several push rods are connected, one end of the push rod is inserted into the filling hole of the upper shaft shoulder, the filling hole is filled with welding material, and the diameter of the end of the filling hole is smaller than the diameter of the filling hole; the upper shaft shoulder is fixedly connected with the rotating device, and the rotating device The machine head is connected with the machine head through the second bearing, and the machine head is fixed under the frame. The rotating device is provided with a guide hole, and the guide block moves up and down along the guide hole.

Preferably, the rotating device includes a driving gear and a driven gear, the driven gear is sleeved on the upper shoulder, the driven gear is fixedly connected to the upper shoulder, and the guide hole is located at the top of the driven gear.

Preferably, the guide block is strip-shaped.

Preferably, both the central shaft and the positioning cylinder are provided with a through hole, and a positioning key is inserted into the through hole, and the central shaft and the positioning cylinder rotate synchronously through the positioning key.

Preferably, a displacement sensor is installed on the guide block.

Preferably, the displacement of the guide block measured by the displacement sensor per unit time is Δx ₂ , the advancing speed of the guide block is V ₂ =Δx ₂ /Δt, the welding speed V ₁ =Δx ₁ /Δt, and Δx ₁ is the upper axis The distance that the shoulder moves relative to the surface of the workpiece, the ratio of the welding speed V ₁ to the propulsion speed V ₂ is ω, ω is compared with the ω _standard given in the welding machine, if ω is greater than 1.1 times the ω _standard , the propulsion force of the linear motor is increased; If ω is less than 0.8 times the ω _standard , reduce the propulsion force of the linear motor.

As a preference, if the ω value and the given ω _standard deviation exceed 0.2 times the ω standard, the linear motor will stop working to ensure that the welding process continues and prevent the filling system from being damaged due to excessive force.

Preferably, the welding process is divided into a welding preheating stage, a welding stable stage and a welding finishing stage, and the relationship between the ω values of the three stages is ω _finishing <ω _preheating <ω _stable .

Beneficial effects: the filling type friction stir welding device with adjustable extrusion speed of the present invention has the following advantages:

(1) The precise and stable filling system ensures uniform and moderate force during the filling process;

(2) Through the measurement of the displacement sensor and the calculation of the internal parameters of the welding machine, the filling speed can be controlled according to the actual demand, and the propulsion force can be selected more scientifically to ensure an appropriate amount of filling metal;

(3) Use different formulas to make suitable filler materials according to the actual welding base metal material, so that the performance of the weld can be greatly improved;

(4) The full metal filling at the beginning and end of welding will not produce a V-shaped notch without metal filling;

(5) The metal in the weld is denser, and the probability of pores and cracks is greatly reduced by traditional double-shaft shoulder friction stir welding technology.

Description of drawings

Figure 1 is a structural diagram of a filled double-shaft shoulder friction stir welding device;

Figure 2 is a structural diagram of a filled double-shaft shoulder friction stir head;

Fig. 3 is a structural diagram of the rotating system;

Fig. 4 is a filling system diagram;

Figure 5 is a sectional view of the guide hole.

In Figure 1, 1 is the lower shaft shoulder; 2 is the stirring needle; 3 is the upper shaft shoulder; 4 is the filling hole; 5 is the driving gear; 6 is the driven gear; 7 is the second bearing; 8 is the sleeve; 9 is the machine 10 is the filling material pushing rod; 11 is the guide hole; 12 is the guide block; 13 is the positioning cylinder; 14 is the positioning key; 15 is the central shaft; 16 is the first bearing; 17 is the central shaft sleeve; 18 is the frame 19 is connecting rod.

Detailed ways

As shown in Figures 1 to 5, a filling-type friction stir welding device with adjustable extrusion speed of the present invention includes a frame 18 on which several linear motors are installed, and the linear motors pass through the connecting rod 19 is connected with the central shaft sleeve 17 located in the frame 18, the central shaft sleeve 17 is connected with the positioning cylinder 13 through the first bearing 16, and there are two first bearings 17, which are respectively located on the two shaft shoulders of the central shaft sleeve 17, The positioning cylinder 13 is sleeved on the central shaft 15 and rotates synchronously with the central shaft 15. The central shaft 15 plays the role of transmitting the axial force and resolving the radial force. The central shaft 15 and the positioning cylinder 13 are provided with through holes, through The positioning key 14 is inserted in the hole, and the central shaft 15 and the positioning cylinder 13 rotate synchronously through the positioning key 14. The lower end of the central shaft 15 is fixedly connected with the guide block 12, and the guide block 12 is connected with two push rods 10, and one end of the push rod 10 Inserted into the filling hole 4 of the upper shoulder 3, the filling hole 4 is filled with welding material, the diameter of the end of the filling hole 4 is smaller than the diameter of the filling hole 4, preventing the welding material in the filling hole 4 from slipping out of the filling hole 4, the upper shoulder The lower part of the 3 is connected with the stirring pin 2, and the stirring pin 2 is connected with the lower shoulder 1 to form the upper shoulder 3 for welding; the upper shoulder 3 is fixedly connected with the rotating device, and the rotating device is connected with the machine head 9 through the second bearing 7, The second bearing 7 defines the outer ring and the inner ring of the second bearing respectively by the sleeve and the pressing plate, the machine head 9 is fixed below the frame 18, the rotating device is provided with a guide hole 11, and the cross section of the guide block 12 is Rectangle, the guide block 12 moves up and down along the guide hole 11.

In the present invention, the rotating device includes a driving gear 5 and a driven gear 6, the driven gear 6 is sleeved on the upper shoulder 3, the driven gear 6 is fixedly connected with the upper shoulder 3, and the guide hole 11 is located at the top of the driven gear 6. At the top, the guide block 12 can pass through the guide hole 11 smoothly, and lubricating oil is applied therein to reduce the friction between the guide block and the guide hole. The upper shoulder 3 is designed to fill the hole 4 to fill the welding material, and the lower end of the welding material touches the workpiece and rubs against it, so that the filling material is evenly spread on the surface of the weld when filling, and is evenly stirred by the stirring needle 2. The fill enters the weld.

In the present invention, a displacement sensor is installed on the guide block 12, and the displacement of the guide block 12 measured by the displacement sensor per unit time is Δx ₂ , and the advancing speed of the guide block 12 is V ₂ =Δx ₂ /Δt, The welding speed of the upper shoulder 3 per unit time is V1=Δx ₁ /Δt, Δx ₁ is the moving distance of the upper shoulder 3, the ratio of the welding speed V ₁ to the advancing speed V ₂ is ω, and ω is equal to the given ω in the welding machine _Standard for comparison, if ω is greater than 1.1 times the ω _standard , then increase the propulsion force of the linear motor; if ω is less than 0.8 times the ω _standard , then reduce the propulsion force of the linear motor; if the ω value is consistent with the given ω _standard If the deviation exceeds 0.2 times the ω standard, the filling system is faulty, and the linear motor stops working to ensure that the welding process continues to prevent the filling system from being damaged due to excessive force. The smaller the ω value, the larger the metal filling amount, the better the weld density, and the adjustment of the extrusion speed is just by controlling the ω value.

The whole welding process can be roughly divided into three stages, welding preheating stage, welding stabilization stage, and welding finishing stage. The ω value of these three stages should be very different. In the welding preheating stage, due to the low welding temperature and slow welding speed, the value of ω should be small; in the stable stage of welding, it should be adjusted according to the specific welding conditions of the weld; The metal filling is full. Usually the relationship between the three stages ω should be: ω _ending < ω _preheating < ω _stable .

In addition, it is necessary to detect the difficulty of metal extrusion through the line energy, and calculate the value of E=r*T/V ₁ , where E is the line energy, r is the rotation speed, T is the torque, and V ₁ is the welding speed . The host machine of the welding machine inquires the maximum pressure value F _max of the linear motor from the database according to the size of E, and ensures that the pressure F of the linear motor is < F _max , which can prevent the filling metal from having poor fluidity due to small heat input and the linear motor to ensure the filling speed. Increasing the pressure F too much leads to damage to the push rod.

The invention can realize the filling of the metal with the same physical and chemical properties as the parent material in the friction stir welding process, and can achieve the purpose of improving the strength, toughness and plasticity by changing the formula of the filler. The host machine of the welding machine calculates the welding line energy by collecting parameters such as welding speed, stirring head torque, and stirring head rotation speed during the welding process, and at the same time calculates the fastest filling speed allowed by welding, thereby limiting the down pressure of the linear motor to prevent the filling metal from flowing due to fluidity. Insufficient damage to the welder.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also possible. It should be regarded as the protection scope of the present invention.

Claims (6)

1. one kind squeezes into the adjustable filled type friction stir weld device of speed, it is characterised in that：Including frame, pacify in the frame Equipped with several linear electric motors, linear electric motors are connected by connecting rod with the central axle sleeve in the frame, and central axle sleeve passes through the One bearing is connected with positioning tube, positioning tube set on center shaft and with central shaft synchronous axial system, the lower end of the central shaft is with leading Block is fixedly connected, and guide block is connected with several catch bars, and catch bar one end is inserted into the filling hole of the shaft shoulder, is filled and is filled out in hole Filled with welding material, the diameter for filling bore end is less than filling bore dia；The upper shaft shoulder is fixedly connected with rotating device, rotation Device is connected by second bearing with head, and head is fixed on below frame, and the rotating device is provided with guide hole, and guide block is along guide hole Move up and down；Displacement transducer, the displacement for the guide block that institute's displacement sensors measure in the unit interval are installed on the guide block For Δ x₂, the fltting speed of guide block is V₂=Δ x₂/ Δ t, welding speed V₁=Δ x₁/ Δ t, Δ x₁For upper shaft shoulder opposite piece table The distance of face movement, welding speed V₁With fltting speed V₂The ratio between be ω, the ω and ω given in welding machine_StandardIt is compared, if ω More than 1.1 times ω_StandardThen increase the propulsive force of linear electric motors；If ω is less than 0.8 times of ω_StandardThen reduce the propulsive force of linear electric motors.

2. according to claim 1 squeeze into the adjustable filled type friction stir weld device of speed, it is characterised in that：The rotation Rotary device includes driving gear and driven gear, and the driven gear is enclosed on the shaft shoulder, and driven gear is fixed with the upper shaft shoulder to be connected Connect, guide hole is located at the top of driven gear.

3. according to claim 1 or 2 squeeze into the adjustable filled type friction stir weld device of speed, it is characterised in that：Institute It is strip to state guide block.

4. according to claim 1 squeeze into the adjustable filled type friction stir weld device of speed, it is characterised in that：In described Mandrel and positioning tube are equipped with through hole, and positioning key is inserted in through hole, and central shaft passes through positioning key synchronous axial system with positioning tube.

5. according to claim 1 squeeze into the adjustable filled type friction stir weld device of speed, it is characterised in that：It is if described ω values and given ω_Standardω standard of the deviation more than 0.2 times then fill system failure, linear electric motors, which are stopped, to be ensured to weld Process continues so as to prevent fill system due to the excessive damage of stress.

6. the adjustable filled type friction stir weld device of speed is squeezed into according to claim 1 or 5, it is characterised in that：Weldering Termination process is divided into welding warm-up phase, welding stabilization sub stage and welding finishing phase, the ω value magnitude relationships of three phases ω_Ending＜ ω_Preheating＜ ω_{It is stable}。