CN107219166B - A kind of determination method of friction coefficient - Google Patents

Abstract

The present invention provides a kind of measuring methods of coefficient of friction, are related to mechanical engineering field.The measuring method of coefficient of friction, which includes: that the first determination unit is fixed, pulls the first plate, detect the first value of thrust of the first plate first pulling force suffered relative to the movement of the first determination unit, the third value of thrust of the second plate of detection third pulling force suffered relative to the movement of the second determination unit；Second value of thrust of the first determination unit rotation the first plate of detection second pulling force suffered relative to the movement of the first determination unit, detects fourth value of thrust of second plate relative to the 4th pulling force suffered by the second determination unit；Flange coefficient of friction is calculated according to third value of thrust；Die entrance area coefficient of friction is calculated according to the first value of thrust, the second value of thrust, third value of thrust and the 4th value of thrust.Measuring friction coefficient device provided by the invention and equipment can detect flange coefficient of friction and die entrance area coefficient of friction simultaneously, improve the working efficiency of measuring friction coefficient device.

Description

A kind of determination method of friction coefficient

technical field

The invention relates to the field of mechanical engineering, in particular to a method for measuring friction coefficient.

Background technique

Due to the outstanding performance of numerical simulation technology in shortening the product design cycle and saving production costs, it has been widely used in the optimization design of sheet metal forming. The accuracy of the simulation results depends on the correct contact model, in which the friction model plays a decisive role.

At present, the friction model is usually established by means of experimental measurement. In the numerical simulation of sheet metal forming, the same friction model is usually used to describe the friction characteristics of the flange area and the die fillet area. In fact, the friction characteristics of the flange area and the die fillet area are obviously different. In the numerical simulation of sheet metal forming, a friction model is used to describe the friction characteristics of these two regions, which causes the simulation results to be distorted. In order to establish a friction model that can accurately describe the friction characteristics of various parts in the actual sheet metal forming process, a device and method that can provide accurate simulation of the friction characteristics of the flange area and the die fillet area during the sheet metal forming process are required.

In response to the above requirements, many devices for measuring friction characteristics in sheet metal forming have appeared in recent years. The more typical friction test devices and methods are as follows:

1. With the help of the flat sliding friction experiment between the stretching machine and the fixture, this method can effectively measure the friction characteristics between the sheet metal in the flange area and the mold.

2. Pull-bending friction test, this method makes one end of the sheet fixed by a fixture, and the other end is connected to the stretching machine, and the friction test is carried out by the elongation and deformation of the sheet, and the deformation resistance of the sheet through the fillet is not removed. The effect is inconsistent with the actual working conditions.

3. The probe method friction test system, this method measures the friction coefficient by installing a probe sensor on the mold. The installation of the probe sensor is destructive to the mold, and the cost is high, and it is not suitable to install the probe at the rounded corner of the die.

4. Disc-pin friction experiment, this method is only suitable for simulating the friction characteristics of the flange area.

These friction testing devices and methods can only measure the friction of one area in the flange area or the corner of the die during sheet metal forming, and cannot detect the friction coefficient of the flange area and the corner area of the die at the same time, resulting in The working efficiency of the friction coefficient determination method is low.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a friction coefficient measurement method, which can simultaneously detect the friction coefficient of the flange area and the friction coefficient of the concave die fillet area, thereby improving the working efficiency of the friction coefficient measurement method.

The present invention provides a technical scheme:

A method for measuring the friction coefficient, which is used for measuring the friction coefficient of the plate to be tested during the plate forming process, the friction coefficient includes the friction coefficient of the flange area and the friction coefficient of the concave die fillet area, and the plate to be tested includes the interconnected For the first plate and the second plate, the method for measuring the friction coefficient includes:

Fix the first measurement unit, pull the first plate, detect the first tension value of the first tension force of the first plate relative to the movement of the first measurement unit, and detect the relative movement of the second plate relative to the first tension value. 2. The third tensile force value of the third tensile force subjected to the movement of the measuring unit, wherein the first measuring unit abuts against the first plate, and the second measuring unit abuts against the second plate;

Pull the first plate, the first measurement unit rotates, detect the second tension value of the second tension force of the first plate relative to the movement of the first measurement unit, and detect the relative movement of the second plate relative to the The fourth tensile force value of the fourth tensile force suffered by the second measuring unit;

calculating the friction coefficient of the flange area according to the third tensile force value;

The friction coefficient of the die fillet area is calculated according to the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value.

Further, in a preferred embodiment of the present invention, the second measuring unit includes a first mold plate and a second mold plate, and the plate to be measured is clamped between the first mold plate and the second mold Between the plates, pulling the second sheet can move relative to the first die plate and the second die plate.

Further, in a preferred embodiment of the present invention, the step of calculating the friction coefficient of the flange area according to the third tensile force value includes:

According to the formula:

Calculate the friction coefficient of the flange area, where f is the friction coefficient of the flange area, F ₃ is the third tensile force value, F _N is the positive pressure of the second measuring unit on the second plate, 2 is the number of the first mold plate and the second mold plate.

Further, in a preferred embodiment of the present invention, the first measuring unit includes a cylindrical mold, and the first plate is abutted against the outer surface of the cylindrical mold.

Further, in a preferred embodiment of the present invention, the die fillet is calculated according to the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value The steps to determine the coefficient of friction of the zone include:

Calculate the friction force according to the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value;

The friction coefficient of the die fillet area is calculated according to the friction force.

Further, in a preferred embodiment of the present invention, the step of calculating the friction force according to the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value includes the following steps: :

calculating the fillet resistance of the second plate relative to the movement of the second measuring unit according to the first tensile force value and the third tensile force value;

calculating the deformation resistance of the second plate relative to the movement of the second measuring unit according to the second tensile force value and the fourth tensile force value;

The frictional force is calculated according to the deformation resistance and the fillet resistance.

Further, in a preferred embodiment of the present invention, the step of calculating the fillet resistance of the second sheet through the second measuring unit according to the first tensile force value and the third tensile force value includes:

According to the formula:

|F ₃ -F ₁ |=F _c

The fillet resistance is calculated, wherein F _C is the fillet resistance, F ₃ is the third pulling force value, and F ₁ is the first pulling force value.

Further, in a preferred embodiment of the present invention, the step of calculating the deformation resistance of the second plate through the second measuring unit according to the second tensile force value and the fourth tensile force value includes:

According to the formula:

|F ₄ -F ₂ |=F _B

The deformation resistance is calculated, wherein F _B is the deformation resistance, F ₄ is the fourth tensile force value, and F ₂ is the second tensile force value.

Further, in a preferred embodiment of the present invention, the step of calculating the friction force according to the deformation resistance and the fillet resistance includes:

According to the formula:

|F _C -F _B |=F _R

The friction force is calculated, _{wherein FB} is the deformation resistance, _FC is the corner resistance, and FR is the friction force.

Further, in a preferred embodiment of the present invention, the step of calculating the friction coefficient of the die fillet area according to the friction force includes:

According to the formula:

Calculate the friction coefficient of the die fillet area, where u is the friction coefficient of the die fillet area, a is the bending angle of the second sheet when it passes through the second measuring unit, F _R is the friction force, F ₃ is the third tension value, and F ₁ is the first tension value.

The beneficial effect of the method for determining the coefficient of friction provided by the present invention is: in the present invention, the first measuring unit is fixed, and the first tensile force value of the first tensile force that the first plate can be moved relative to the first measuring unit is detected, and the The third tensile force value of the third tensile force that the second plate can move relative to the second measuring unit; the first measuring unit rotates to detect the second tensile force that the first plate can move relative to the first measuring unit. The tensile force value is used to detect the fourth tensile force value of the second plate relative to the fourth tensile force that the second measuring unit is subjected to; calculate the friction coefficient of the flange area according to the third tensile force value; The third and fourth tension values are used to calculate the friction coefficient in the fillet area of the die. In the present invention, the friction coefficient of the flange area and the friction coefficient of the concave die fillet area can be detected at the same time, thereby improving the working efficiency of the method for measuring the friction coefficient.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore do not It should be regarded as a limitation of the scope, and for those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a friction coefficient measuring device provided in an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a base of a friction coefficient measuring device provided in an embodiment of the present invention.

3 is a schematic structural diagram of a first die set of a first measuring unit of a friction coefficient measuring device provided in an embodiment of the present invention.

4 is a schematic structural diagram of a cylindrical die of a first die set of a first measuring unit of a friction coefficient measuring device provided in an embodiment of the present invention.

5 is a schematic structural diagram of a bearing of a first die set of a first measuring unit of a friction coefficient measuring device provided in an embodiment of the present invention.

FIG. 6 is a schematic structural diagram of a traction device of a friction coefficient measuring device provided in an embodiment of the present invention.

FIG. 7 is a schematic structural diagram of a clamp system of a friction coefficient measuring device provided in an embodiment of the present invention.

FIG. 8 is a block diagram of the composition of a friction coefficient measuring device provided by an embodiment of the present invention.

FIG. 9 is a flowchart of a method for determining a coefficient of friction provided by an embodiment of the present invention.

FIG. 10 is a flowchart of sub-steps of step S600 of the friction coefficient determination method provided by the embodiment of the present invention.

FIG. 11 is a flowchart of sub-steps of step S610 of the friction coefficient determination method provided by the embodiment of the present invention.

Icon: 10-friction coefficient measuring device; 100-base; 110-first fixing part; 112-first base plate; 1122-groove; 114-support part; 116-cavity; 120-base plate; 130-support plate ; 132-through hole; 134-pin hole; 140-limiting piece; 142-positioning part; 144-abutting part; 200-first measuring unit; 210-first detection device; 220-first die set; - Cylindrical mold; 2222 - first keyway; 2224 - second keyway; 224 - rotating shaft; 226 - bearing; 2262 - bearing body; 310-The second detection device; 320-Pressure device; 330-The second die set; 332-The first die plate; 334-The second die plate; 430-top plate; 440-connector; 500-clamp system; 510-holding part; 520-connecting part; 530-second fixing part; 532-first baffle; 534-second baffle; 536-connecting column ; 538-fixing buckle; 539-accommodating cavity; 600-display terminal; 20-plate to be tested; 21-first plate; 22-second plate.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "inside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or when the product of the invention is used. Orientation or positional relationship that is usually placed, or the orientation or positional relationship that is commonly understood by those skilled in the art, is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation , constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

Furthermore, the terms "first", "second", etc. are only used to differentiate the description and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "arrangement" and "connection" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection, or It can be connected in one piece; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Example

Referring to FIG. 1, this embodiment provides a method for determining the coefficient of friction. The method for determining the coefficient of friction provided by this embodiment can simultaneously detect the coefficient of friction in the flange area and the coefficient of friction in the fillet area of the die, which improves the method for determining the coefficient of friction. work efficiency.

The friction coefficient measurement method provided in this embodiment is completed by the friction coefficient measurement device 10 .

In this embodiment, the friction coefficient measuring device 10 is used to measure the friction coefficient of the plate 20 to be tested during the plate forming process. The plate to be tested 20 includes a first plate 21 and a second plate 22 that are connected to each other, and the friction coefficient includes the flange area. The coefficient of friction and the coefficient of friction in the fillet area of the die, in this embodiment, the first plate 21 is used to detect the coefficient of friction in the fillet area of the die, and the second plate 22 is used to detect the coefficient of friction in the flange area.

It should be noted that, in this embodiment, the plate to be tested 20 includes a first plate 21 and a second plate 22, but it is not limited to this. In other embodiments of the present invention, the plate to be tested 20 may also include a third plate and the fourth plate, the solutions equivalent to this embodiment, which can achieve the effect of this embodiment, are all within the protection scope of the present invention.

In this embodiment, the width of the first plate 21 and the second plate 22 is 0.034-0.4 times the length.

In this embodiment, the friction coefficient measuring device 10 includes a base 100 , a clamp system 500 , a traction device 400 , a first measuring unit 200 and a second measuring unit 300 respectively disposed on the base 100 .

The pulling device 400 is used for pulling the first plate 21 to move the first plate 21 relative to the first measuring unit 200 and to drive the first plate 21 to move relative to the second measuring unit 300 .

The first measurement unit 200 is movably connected to the base 100 for applying pressure to the first plate 21 and for measuring the relative movement of the first plate 21 to the first measurement unit when the first measurement unit 200 and the base 100 are relatively stationary. 200 The first pulling force value of the first pulling force experienced by the movement. The first measuring unit 200 is further configured to measure the second tensile force value of the second tensile force that the first plate 21 moves relative to the first measuring unit 200 when the first measuring unit 200 moves relative to the base 100 .

The second measuring unit 300 is used for applying pressure to the second plate 22 , and is used for measuring the third pressure on the second plate 22 relative to the movement of the second measuring unit 300 when the first measuring unit 200 and the base 100 are relatively stationary. The third pulling force value of the pulling force is also used to measure the fourth pulling force value of the fourth pulling force that the second plate 22 receives relative to the second measuring unit 300 when the first measuring unit 200 moves relative to the base 100 .

The clamp system 500 is rotatably connected with the base 100 , and the clamp system 500 is used for fixing the second plate 22 to make the second plate 22 move linearly.

Please refer to FIG. 1 and FIG. 2 , in this embodiment, the base 100 includes a first fixing portion 110 , a bottom plate 120 , two supporting plates 130 and a limiting member 140 . The two supporting plates 130 are both connected to the bottom plate 120 . The two support plates 130 are disposed opposite to each other, and the two support plates 130 are provided with through holes 132 and pin holes 134 . Both the through holes 132 and the pin holes 134 are matched with the first measuring unit 200 , and the first fixing portion 110 and the bottom plate 120 are separated from each other. One end of each support plate 130 is connected, and each of the second measurement units 300 is connected to the first fixing portion 110 . The limiting member 140 is connected to one end of the bottom plate 120 away from the two supporting plates 130 , and the limiting member 140 is connected to the fixture system 500 to fix the fixture system 500 .

In this embodiment, the first fixing portion 110 includes a first substrate 112 and a supporting portion 114 , a groove 1122 is formed on the first substrate 112 , the second measuring unit 300 is arranged in the groove 1122 , and the second measuring unit 300 and the The support portion 114 is connected, the first substrate 112 and the support portion 114 form a cavity 116 , and the first plate 21 and the second measurement unit 300 pass through the cavity 116 .

The limiting member 140 includes a positioning portion 142 and a resisting portion 144. The positioning portion 142 is connected to one side of the bottom plate 120, the resisting portion 144 is connected to the other side of the bottom plate 120, and the fixture system 500 is connected to the positioning portion 142, so that the fixture system 500 is rotatable relative to the base plate 120 . When the clamp system 500 is rotated to be parallel to the width direction of the base plate 120 , the abutting portion 144 abuts against the clamp system 500 , so that the clamp system 500 is fixed relative to the base plate 120 .

In this embodiment, the first measurement unit 200 includes a first detection device 210 and a first die set 220 . The first detection device 210 is connected to the first plate 21 , and the first die set 220 abuts against the first plate 21 .

In this embodiment, the first detection device 210 is a tension sensor.

Please refer to FIG. 3 , in this embodiment, the first die set 220 includes a cylindrical die 222 , a rotating shaft 224 , a bearing 226 and a fixing pin 228 , the bearing 226 is sleeved on the rotating shaft 224 , and the cylindrical die 222 is sleeved At the bearing 226 , the cylindrical mold 222 abuts against the second plate 22 . The bearing 226 cooperates with the through hole 132 so that the cylindrical mold 222 can rotate relative to the base 100 . Attached to the cylindrical mold 222 is a securing pin 228 that engages with the optional pin hole 134 to secure the cylindrical mold 222 .

Referring to FIG. 4 , in this embodiment, the cylindrical mold 222 is provided with a first key groove 2222 and a second key groove 2224 , the first key groove 2222 is matched with the bearing 226 , and the second key groove 2224 is matched with the fixing pin 228 .

Referring to FIG. 5 , in this embodiment, the bearing 226 includes a bearing body 2262 and an outer circular protrusion 2264 , the outer circular protrusion 2264 is disposed on the bearing body 2262 , and the outer circular protrusion 2264 is matched with the first key groove 2222 , so that the The bearing 226 is fixedly connected to the cylindrical mold 222 .

In this embodiment, when the pulling device 400 pulls the first plate 21 to move, the cylindrical mold 222 can rotate relative to the base 100 or be stationary.

In this embodiment, the pulling device 400 pulls the first plate 21 to move, the bearing 226 cooperates with the through hole 132 , the cylindrical mold 222 rotates under the force of the first plate 21 , the fixing pin 228 and the second key groove 2224 and the pin The holes 134 cooperate to secure the cylindrical mold 222 relative to the base 100 .

In this embodiment, the cylindrical mold 222 is cylindrical. The first plate 21 abuts against the outer surface of the cylindrical mold 222 .

In this embodiment, when the fixing pin 228 is engaged with the pin hole 134 , the cylindrical mold 222 is stationary relative to the base 100 , and the first detection device 210 detects the pressure of the first plate 21 when it moves relative to the cylindrical mold 222 . The first pull value of the first pull.

When the fixing pin 228 is not matched with the pin hole 134, and the cylindrical mold 222 can rotate relative to the base 100, the first detection device 210 can detect the first plate 21 when it moves relative to the cylindrical mold 222. The second pull value of the second pull.

Please continue to refer to FIG. 1 , in this embodiment, the second measuring unit 300 includes a second detecting device 310 , a pressing device 320 and a second die set 330 , and the second detecting device 310 is respectively connected to the first plate 21 and the second plate 22 is connected, the second die set 330 is connected with the second plate 22 , and the pressing device 320 is connected with the second die set 330 .

The second mold set 330 includes a first mold plate 332 and a second mold plate 334 . The first mold plate 332 and the second mold plate 334 are both connected to the first fixing portion 110 , and the second plate 22 is clamped to the first mold plate 332 Between the second mold plate 334 and the second mold plate 334 , the pressing device 320 is connected to the first mold plate 332 .

In this embodiment, the first mold plate 332 is disposed in the groove 1122 , the second mold plate 334 is connected to the support portion 114 , and the first plate 21 and the first mold plate 332 pass through the cavity 116 .

In the present embodiment, when the fixing pin 228 is engaged with the pin hole 134, the cylindrical mold 222 is stationary relative to the base 100, and the second detection device 310 detects the second plate 22 relative to the first mold plate 332 and the second mold The third pulling force value of the third pulling force when the plate 334 moves.

When the fixing pin 228 is not matched with the pin hole 134, and the cylindrical mold 222 can rotate relative to the base 100, the second detection device 310 can detect the second plate 22 relative to the first mold plate 332 and the second mold plate 334 The fourth pulling force value of the fourth pulling force when exercising.

In this embodiment, the second detection device 310 is a tension sensor.

The pressurizing device 320 is an electro-hydraulic servo loading cylinder.

It should be noted that, in this embodiment, the pressurizing device 320 is an electro-hydraulic servo loading cylinder, but it is not limited to this. In other embodiments of the present invention, the pressurizing device 320 may also be other devices that can apply pressure. Solutions equivalent to this embodiment, which can achieve the effects of this embodiment, are all within the protection scope of the present invention.

6, the traction device 400 includes a bracket 410, a servo electric cylinder 420, a top plate 430 and a connector 440. The top plate 430 is connected to one end of the bracket 410, the servo electric cylinder 420 is connected to the top plate 430, and one side of the connector 440 is connected to the servo The electric cylinder 420 is fixedly connected and movably connected with the bracket 410 , and the other side of the connector 440 is connected with the first plate 21 .

In this embodiment, the side of the connector 440 away from the servo electric cylinder 420 is connected to the first plate 21 through the first detection device 210 .

Please refer to FIG. 7 , the clamp system 500 includes a holding part 510 , a connecting part 520 and a second fixing part 530 , the holding part 510 and the connecting part 520 are both connected with the second fixing part 530 , and the connecting part 520 is rotatably connected with the positioning part 142 , so that the second fixing portion 530 can be rotated relative to the base. When the second fixing portion 530 is rotated to be parallel to the width direction of the bottom plate 120 , the abutting portion 144 is abutted against the holding portion 510 , so that the second fixing portion 530 is relatively The bottom plate 120 is fixed.

The second fixing portion 530 includes a first baffle 532 , a second baffle 534 , a connecting post 536 and a fixing buckle 538 . The first baffle 532 and the second baffle 534 are connected by a connecting column 536 , a accommodating cavity 539 is formed between the first baffle 532 , the second baffle 534 and the connecting column 536 , the second plate 22 and the first mold plate 332 Pass through the accommodating cavity 539 . The fixing part can make the second plate 22 move in a straight line when it moves relative to the first mold plate 332 and the second mold plate 334 , so as to ensure the accuracy of measurement.

Referring to FIG. 8 , in this embodiment, the friction coefficient measuring device 10 further includes a display terminal 600 , and the display terminal 600 is connected to the first detection device 210 and the second detection device 310 for displaying the first tensile force value, the second The second tension value, the third tension value and the fourth tension value.

In this embodiment, the third tensile force value is equal to the fourth tensile force value. The friction coefficient of the flange area can be calculated according to the third or fourth pull force value, and the friction coefficient of the die fillet area can be calculated according to the first pull force value, the second pull force value, the third pull force value and the fourth pull force value.

In this embodiment, the first plate 21 moves relative to the cylindrical mold 222 , and the cylindrical mold 222 is stationary relative to the base 100 or the first plate 21 moves to generate different resistances. When the cylindrical mold 222 moves relative to the base 100 , the movement of the first sheet 21 relative to the cylindrical mold 222 only generates deformation resistance. When the cylindrical mold 222 is stationary relative to the base 100 , the movement of the first plate 21 relative to the cylindrical mold 222 generates fillet resistance, and the fillet resistance includes deformation resistance and friction resistance.

Please refer to Fig. 9, the concrete working process of the friction coefficient determination method provided by this embodiment is as follows:

In step S100 , the first measuring unit 200 is fixed, the first plate 21 is pulled, and the first tensile force value of the first pulling force that the first plate 21 can move relative to the first measuring unit 200 is detected.

In this embodiment, the cylindrical mold 222 is fixed relative to the base 100 , the first plate 21 is pulled by the pulling device 400 to move the first plate 21 relative to the cylindrical mold 222 , and the first detection device 210 detects the first plate 21 . The first pulling force value of the first pulling force that a plate 21 moves.

Step S200 , fix the first measuring unit 200 , pull the first plate 21 to drive the second plate 22 to move, and detect the third pulling force of the second plate 22 relative to the third pulling force of the second measuring unit 300 value.

In this embodiment, the cylindrical mold 222 is fixed relative to the base 100 , the pulling device 400 pulls the first plate 21 and drives the second plate 22 to move relative to the first mold plate 332 and the second mold plate 334 . The detection device 310 detects the third tensile force value of the third tensile force that the second plate 22 moves relative to the first mold plate 332 and the second mold plate 334 .

Step S300 , pulling the first plate 21 to make the first measuring unit 200 rotate, and detecting the second tensile force value of the second pulling force that the first plate 21 can move relative to the first measuring unit 200 .

In this embodiment, the cylindrical mold 222 is rotatable relative to the base 100, the pulling device 400 pulls the first plate 21 to move the first plate 21 relative to the cylindrical mold 222, and the first detection device 210 detects the first plate 21. The third tensile force value of the third tensile force for the movement of the plate 21 .

Step S400 , pulling the first plate 21 to rotate the first measuring unit 200 , and detecting a fourth tensile force value of the second plate 22 relative to the fourth tensile force that the second measuring unit 300 can receive.

In this embodiment, the cylindrical mold 222 can be rotated relative to the base 100, and the pulling device 400 pulls the first plate 21 and drives the second plate 22 to move relative to the first mold plate 332 and the second mold plate 334. The second detection device 310 detects the fourth tensile force value of the fourth tensile force that the second plate 22 moves relative to the first mold plate 332 and the second mold plate 334 .

It should be understood that, in other embodiments of the present invention, steps S100 and S200 and steps S300 and S400 in the method for determining the friction coefficient of the present invention may be interchanged, and steps S300 and S400 may be performed first and then steps S100 and S200 may be performed.

In step S500, the friction coefficient of the flange area is calculated according to the third tensile force value.

In this embodiment, according to the formula Calculate the friction coefficient of the flange area;

Where f is the friction coefficient of the flange area, F ₃ is the third tensile force value, and F _N is the positive pressure of the second measuring unit 300 on the second plate 22 .

In this embodiment, the friction coefficient of the flange area may be calculated by the processor according to the third tensile force value, and the friction coefficient of the flange area may be calculated manually.

Step S600, calculating the friction coefficient of the fillet area of the die according to the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value.

In this embodiment, a formula is used to calculate the friction coefficient of the fillet area of the die according to the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value.

Please refer to FIG. 10 , in step S610 , the friction force is calculated according to the first tension value, the second tension value, the third tension value and the fourth tension value.

In this embodiment, the friction force is first calculated by formulas according to the first tension value, the second tension value, the third tension value and the fourth tension value, and then the friction coefficient in the fillet area of the die is further calculated.

Please refer to FIG. 11, step S611, calculating the fillet resistance of the second plate 22 passing through the second measuring unit 300 according to the first tensile force value and the third tensile force value;

In this embodiment, according to the formula:

|F ₃ -F ₁ |=F _c

Calculate the fillet resistance. Among them, FC is the fillet resistance, F3 is the third pulling force value, and F1 is the first pulling force value.

Step S612, calculating the deformation resistance of the second plate 22 through the second measuring unit 300 according to the second tensile force value and the fourth tensile force value;

In this example, the formula is used:

|F ₄ -F ₂ |=F _B

The deformation resistance is calculated, where FB is the deformation resistance, F4 is the fourth tension value, and F2 is the second tension value.

It should be understood that, in other embodiments of the present invention, step S206 and step S207 in the method for determining the friction coefficient of the present invention may be interchanged, and step S207 may be performed first and then step S206.

In step S613, the friction force is calculated according to the deformation resistance and the fillet resistance.

In this embodiment, according to the formula:

|F _C -F _B |=F _R

Calculate the friction force, where _FR is the friction force.

Please continue to refer to FIG. 10 , in step S620 , the friction coefficient of the fillet area of the die is calculated according to the friction force.

In this example, the formula is used:

Calculate the coefficient of friction in the die fillet area.

Wherein u is the friction coefficient of the die fillet area, a is the bending angle of the second plate 22 when it passes through the second measuring unit 300, F _R is the friction force, F ₃ is the third tensile force value, and F ₁ is the The first pull value.

It should be understood that, in other embodiments of the present invention, step S620 and steps S610-S613 in the friction coefficient determination method of the present invention can be interchanged, and steps S610-S613 can be performed first and then step S620.

The working principle of the friction coefficient determination method provided in this embodiment: In this embodiment, when the fixing pin 228 is matched with the pin hole 134 , the cylindrical mold 222 is stationary relative to the base 100 , and the pulling device 400 pulls the first plate 21 movement to drive the second plate 22 to move. The first detection device 210 detects the first tensile force value of the first tensile force when the first plate 21 moves relative to the cylindrical mold 222, and the second detection device 310 detects the second plate 22 relative to the first mold plate 332 and the first tensile force. The third pulling force value of the third pulling force for the movement of the second die plate 334 . When the fixing pin 228 is not matched with the pin hole 134 , the cylindrical mold 222 can rotate relative to the base 100 , and the pulling device 400 pulls the first plate 21 to move, so as to drive the second plate 22 to move. The first detection device 210 detects the second tensile force value of the second tensile force when the first plate 21 moves relative to the cylindrical mold 222, and the second detection device 310 detects the second plate 22 relative to the first mold plate 332 and the second tensile force. The fourth pulling force value of the fourth pulling force for the movement of the second die plate 334 . Calculate the friction coefficient of the flange area according to the third tension value or the fourth tension value, and calculate the friction coefficient of the die fillet area according to the first tension value, the second tension value, the third tension value and the fourth tension value.

To sum up, in the friction coefficient measurement method provided in this embodiment, in this embodiment, the first measurement unit 200 is movably connected with the base 100 to apply pressure to the first plate 21 , and the second measurement unit 300 is used for the measurement of the first plate 21 . The two plates 22 exert pressure, and when the first measuring unit 200 and the base 100 are relatively stationary, the first pulling force value of the first pulling force of the first plate 21 moving relative to the first measuring unit 200 is measured; the first measuring unit 200 The third tensile force value of the third tensile force experienced by the movement of the second plate 22 relative to the second measuring unit 300 is measured. When the first measuring unit 200 moves relative to the base 100, the second tensile force value of the second tensile force of the first plate 21 relative to the movement of the first measuring unit 200 is measured, and the second measuring unit 300 measures the relative The fourth tensile force value of the fourth tensile force subjected to the movement of the second measuring unit 300 . And calculate the friction coefficient of flange area according to the third tension value or fourth tension value, and calculate the friction coefficient of the die fillet area according to the first tension value, the second tension value, the third tension value and the fourth tension value. The friction coefficient determination method provided by the invention can simultaneously detect the friction coefficient of the flange area and the friction coefficient of the die fillet area, thereby improving the working efficiency of the friction coefficient determination method.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A method for measuring the coefficient of friction, for measuring the coefficient of friction of the plate to be measured in the plate forming process, the coefficient of friction comprising the coefficient of friction in the flange area and the coefficient of friction in the concave die fillet area, and the plate to be measured includes a mutual coefficient of friction. The connected first plate and the second plate are characterized in that the friction coefficient measuring device comprises a base, a traction device respectively arranged on the base, a first measuring unit and a second measuring unit, the first measuring unit and the second measuring unit. The measuring unit is movably connected with the base, and the method for measuring the friction coefficient includes: Fixing the first measuring unit, the pulling device pulls the first plate to drive the second plate to move, and detects the first pulling force of the first plate relative to the movement of the first measuring unit The first tensile force value is detected, and the third tensile force value of the third tensile force experienced by the movement of the second plate relative to the second measuring unit is detected, wherein the first measuring unit is in abutment with the first plate, and the The second measuring unit is in abutment with the second plate; The pulling device pulls the first plate, so that the first measuring unit rotates, detects a second pulling force value of the second pulling force that the first plate moves relative to the first measuring unit, and detects the The fourth tensile force value of the second plate relative to the fourth tensile force experienced by the second measuring unit; calculating the friction coefficient of the flange area according to the third tensile force value; The friction coefficient of the die fillet area is calculated according to the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value. 2 . The method for measuring friction coefficient according to claim 1 , wherein the second measuring unit comprises a first die plate and a second die plate, and the plate to be measured is clamped on the first die plate. 3 . and the second mold plate, the second plate can be moved relative to the first mold plate and the second mold plate by pulling the second plate. 3. the measuring method of friction coefficient according to claim 2 is characterized in that, the described step of calculating described flange area friction coefficient according to described third tension value comprises: According to the formula: Calculate the friction coefficient of the flange area; Wherein, f is the friction coefficient of the flange area, F ₃ is the third tensile force value, F _N is the positive pressure of the second measuring unit on the second plate, and the value 2 is the first die plate and the sum of the number of the second die plate. 4 . The method for measuring friction coefficient according to claim 1 , wherein the first measuring unit comprises a cylindrical mold, and the first plate abuts against the outer surface of the cylindrical mold. 5 . 5 . The method for measuring friction coefficient according to claim 1 , wherein the calculation is based on the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value. 6 . The steps of the friction coefficient of the die fillet area include: Calculate the friction force according to the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value; The friction coefficient of the die fillet area is calculated according to the friction force. 6 . The method for measuring friction coefficient according to claim 5 , wherein the calculation is based on the first tensile force value, the second tensile force value, the third tensile force value and the fourth tensile force value. 7 . The steps to generate friction include: calculating the fillet resistance of the second plate relative to the movement of the second measuring unit according to the first tensile force value and the third tensile force value; calculating the deformation resistance of the second plate relative to the movement of the second measuring unit according to the second tensile force value and the fourth tensile force value; The frictional force is calculated according to the deformation resistance and the fillet resistance. 7. The method for measuring friction coefficient according to claim 6, wherein the step of calculating the fillet resistance of the second plate through the second measuring unit according to the first tensile force value and the third tensile force value comprises: According to the formula: |F ₃ -F ₁ |=F _c The fillet resistance is calculated, wherein F _C is the fillet resistance, F ₃ is the third pulling force value, and F ₁ is the first pulling force value. 8 . The method for measuring friction coefficient according to claim 6 , wherein the step of calculating the deformation resistance of the second plate through the second measuring unit according to the second tensile force value and the fourth tensile force value comprises the following steps: 9 . : According to the formula: |F ₄ -F ₂ |=F _B The deformation resistance is calculated, wherein F _B is the deformation resistance, F ₄ is the fourth tensile force value, and F ₂ is the second tensile force value. 9. The method for measuring friction coefficient according to claim 6, wherein the step of calculating the friction force according to the deformation resistance and the fillet resistance comprises: According to the formula: |F _C -F _B |=F _R The friction force is calculated, _{wherein FB} is the deformation resistance, _FC is the corner resistance, and FR is the friction force. 10. The method for measuring friction coefficient according to claim 5, wherein the step of calculating the friction coefficient of the die fillet area according to the friction force comprises: According to the formula: Calculate the friction coefficient of the die fillet area, where u is the friction coefficient of the die fillet area, a is the bending angle of the second sheet when it passes through the second measuring unit, F _R is the friction force, F ₃ is the third tension value, and F ₁ is the first tension value.