Tension and compression two-way force transmission device and operation method

Abstract

The invention belongs to the technical field of wind tunnel balances of aviation weather dynamic experiment measurement equipment, and particularly relates to a tension-compression bidirectional force transmission device and an operation method. The tension-compression bidirectional force transmission device comprises a pull rod with a conical matching surface, an upper knife edge, a middle knife edge, a lower knife edge, a pull rod locking nut, a first connecting rod, a force sensor, a second connecting rod, a spring box, a third connecting rod and an electric cylinder motor integrated body; according to the invention, a series knife edge structure is used for loading the compression force, a built-in pull rod structure is used for loading in the stretching direction, then one set of force transmission device is used for completing bidirectional loading of the wind tunnel balance, the technical scheme that two sets of force transmission devices are adopted for bidirectional loading in the past is replaced, the space occupation of the system is reduced, and the equipment cost is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of wind tunnel balances for aerospace aerodynamic experimental measurement equipment, and specifically relates to a tension-compression bidirectional force transmission device and an operating method. Background Art

[0002] Wind tunnel balances are used to measure the aerodynamic loads acting on aircraft in wind tunnel tests. According to the working principle, they can be divided into mechanical balances, fiber optic balances, piezoelectric balances, strain balances, etc. The strain balance is currently commonly used. The strain balance adopts the principle of strain electrical measurement. Strain gauges are attached to sensitive elements to form an electrical bridge. The strain of the material body under load deformation is converted into an electrical signal for measurement. The mapping relationship between load and electrical signal is established through pre-calibration. The aerodynamic load of the aircraft can be calculated according to the measured electrical signal and the relationship obtained during calibration.

[0003] The calibration of a wind tunnel balance to obtain the coefficient of relationship between its output load and voltage is one of the key steps in developing a wind tunnel balance. The commonly used wind tunnel balance calibration method is to install the wind tunnel balance on a special calibration frame, install a special loading head on the balance, apply a predetermined load to the loading point on the loading head through a force-applying mechanism, and simultaneously record the load value of the balance and the output signal of the balance, and then use mathematical methods to calculate the coefficient of relationship between the load and the signal.

[0004] With the development of electronic technology, computer technology, control and measurement technology, the capabilities and automation of balance calibration equipment in loading, measurement and data processing have been greatly improved. A number of various types of automatic calibration equipment have been developed at home and abroad. Computers are used for centralized control, and weights, electric cylinders, hydraulic cylinders, etc. are used for automatic loading. In order to reduce the coupling interference of directional force loading, the force transmission device design mainly adopts flexible force transmission methods such as steel belts, flexible rods or universal ball joint bearings. The main defect of this method is that it can only carry out unidirectional tensile loading, resulting in the need to use two sets of devices to achieve bidirectional loading of the balance. The overall equipment will be more complicated and occupy a large space, and the equipment cost is higher. Summary of the invention

[0005] In response to the problem that existing force transmission devices are unable to achieve bidirectional loading of tension and compression, the present application proposes a bidirectional force transmission device for tension and compression and an operating method, which adopts a series knife-edge structure to load the compressive force and a built-in pull rod structure to load in the tensile direction, thereby achieving the purpose of completing bidirectional loading of the wind tunnel balance with one set of devices.

[0006] Technical solution 1 adopted in this application: A tension and compression bidirectional force transmission device, comprising a pull rod with a tapered mating surface, an upper knife edge, a middle knife edge, a lower knife edge, a pull rod locking nut, a first connecting rod, a force sensor, a second connecting rod, a spring box, a third connecting rod, and an electric cylinder motor integrated body; The upper cutting edge, the middle cutting edge and the lower cutting edge are coaxially arranged in sequence from top to bottom, and a tie rod locking nut is fixedly installed at the lower part of the lower cutting edge. The tie rod with a tapered fitting surface passes through the upper cutting edge, the middle cutting edge and the lower cutting edge in sequence, and is threadedly connected with the tie rod locking nut. The tie rod with a tapered fitting surface is coaxially arranged with the upper cutting edge; the tie rod locking nut is connected with the first connecting rod, the force sensor, the second connecting rod, the spring box, the third connecting rod, and the electric cylinder motor integrated body in sequence.

[0007] Furthermore, the upper part of the pull rod with a tapered fitting surface is a tapered structure, and the top surface of the pull rod with a tapered fitting surface has an "I"-shaped groove; the upper end of the upper cutting edge is a flange structure end, and the flange structure end is connected to the loading head used for wind tunnel balance calibration; an inner tapered hole is arranged inside the flange structure end, and the tapered structure cooperates with the inner tapered hole; the lower end of the upper cutting edge, the upper and lower ends of the middle cutting edge, and the upper end of the lower cutting edge are all cutting edge structures; the cutting edge structure of the middle cutting edge cooperates with the cutting edge structure of the upper cutting edge and the cutting edge structure of the lower cutting edge to transmit the clamping force; the upper end of the pull rod locking nut is a flange structure, and the flange structure is fixedly installed on the lower cutting edge, and the pull rod locking nut has an upper threaded hole and a lower threaded hole, the upper threaded hole is threadedly connected to the lower end of the pull rod with a tapered fitting surface, and the lower threaded hole is threadedly connected to the first connecting rod.

[0008] Furthermore, a 20 mm deep avoidance groove is provided on the top surface of the upper blade.

[0009] Technical solution 2 adopted in this application: The present application also discloses an operation method of a tension-compression bidirectional force transmission device, which is implemented by using a tension-compression bidirectional force transmission device described in technical solution 1, and comprises the following steps: Step 1: Prepare a bidirectional force transmission device for tension and compression, and ensure that the tie rod with a tapered mating surface passes through the upper cutting edge, the middle cutting edge, and the lower cutting edge in sequence along the center and is threadedly fastened to the tie rod locking nut; when the upper cutting edge, the middle cutting edge, and the lower cutting edge are pressed, the tie rod with a tapered mating surface is separated from the inner and outer conical surfaces of the upper cutting edge; connect the flange of the upper cutting edge to the loading head of the calibrated balance; Step 2: The drive motor rotates to make the electric cylinder contract, the middle blade and the upper blade gradually separate, and the pull rod with the tapered mating surface moves downward until the tapered structure and the inner tapered hole are pressed together, while monitoring the output force value of the sensor. When the predetermined tensile load is reached, the motor stops running. At this time, the force transmitted by the tension and compression bidirectional force transmission device is the tensile force; Step 3: Drive the motor to rotate to extend the electric cylinder, and the pull rod with the tapered mating surface moves upward. The tapered surface and the inner tapered surface of the upper cutting edge are gradually separated, and the middle cutting edge and the upper cutting edge are gradually compressed until they are tightly fitted with the cutting edge of the lower cutting edge. At the same time, the output force value of the sensor is monitored. When the predetermined compression load is reached, the motor stops running. At this time, the force transmitted by the tension and compression bidirectional force transmission device is the compression force.

[0010] This application has the following beneficial effects: This application adopts a combination of a knife-edge structure and a pull rod to realize the bidirectional loading of tension and compression of the load force during the calibration of the wind tunnel balance. A set of force transmission devices can be used to realize the bidirectional calibration loading of the balance force, which is used to replace the previous technical solution of using two sets of force transmission devices for bidirectional loading. While ensuring flexible force transmission, it realizes force transmission in both the tensile and compressive directions, effectively reducing costs and reducing the space occupied by the equipment. The combined application of the pull rod and the knife edge realizes the transmission of the force transmission device in both the pulling and compressing directions, while ensuring that the force transmission device has good flexibility, avoiding the coupling interference of multiple force transmission devices being loaded simultaneously during the calibration of the wind tunnel balance, and improving the accuracy of the balance calibration. The centering effect of the conical surface fit and the knife edge fit is used to ensure the accuracy of the force application point. The high-precision sensor monitors the magnitude of the force to ensure the accuracy of the force value applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is an axonometric diagram of the tension and compression bidirectional force transmission device of the present application; Figure 2 This is an assembly diagram of the tension and compression bidirectional force transmission device of the present application; Figure 3 The transmission tension state diagram of this application; Figure 4 This is the transmission pressure state diagram of this application.

[0012] In the figure: 1-tie rod with tapered mating surface, 2-upper cutting edge, 3-middle cutting edge, 4-lower cutting edge, 5-tie rod locking nut, 6-first connecting rod, 7-force sensor, 8-second connecting rod, 9-spring box, 10-third connecting rod, 11-electric cylinder motor integrated body. DETAILED DESCRIPTION

[0013] The present application will be described in detail below in conjunction with the accompanying drawings, but it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of the structure and technical common knowledge is omitted to avoid unnecessary confusion of the concept of the present application.

[0014] Embodiment 1: Combination Figure 1-4The present application discloses a tension and compression bidirectional force transmission device, including a pull rod 1 with a tapered mating surface, an upper knife edge 2, a middle knife edge 3, a lower knife edge 4, a pull rod locking nut 5, a first connecting rod 6, a force sensor 7, a second connecting rod 8, a spring box 9, a third connecting rod 10, and an electric cylinder motor integrated body 11; The upper cutting edge 2, the middle cutting edge 3, and the lower cutting edge 4 are coaxially arranged from top to bottom, and a tie rod locking nut 5 is fixedly installed at the lower part of the lower cutting edge 4. The tie rod 1 with a tapered fitting surface passes through the upper cutting edge 2, the middle cutting edge 3, and the lower cutting edge 4 in sequence, and is threadedly connected with the tie rod locking nut 5. The tie rod 1 with a tapered fitting surface is coaxially arranged with the upper cutting edge 2; the tie rod locking nut 5 is connected with the first connecting rod 6, the force sensor 7, the second connecting rod 8, the spring box 9, the third connecting rod 10, and the electric cylinder motor assembly 11 in sequence.

[0015] Furthermore, the upper part of the pull rod 1 with a tapered fitting surface is a tapered structure, and the top surface of the pull rod 1 with a tapered fitting surface has an "I"-shaped groove; the upper end of the upper cutting edge 2 is a flange structure end, and the flange structure end is connected to the loading head used for wind tunnel balance calibration; an inner tapered hole is arranged inside the flange structure end, and the tapered structure cooperates with the inner tapered hole; the lower end of the upper cutting edge 2, the upper and lower ends of the middle cutting edge 3 and the upper end of the lower cutting edge 4 are all cutting edge structures; the cutting edge structure of the middle cutting edge 3 cooperates with the cutting edge structure of the upper cutting edge 2 and the cutting edge structure of the lower cutting edge 4 to transmit the clamping force; the upper end of the pull rod locking nut 5 is a flange structure, and the flange structure is fixedly installed on the lower cutting edge 4, and the pull rod locking nut 5 has an upper threaded hole and a lower threaded hole, the upper threaded hole is threadedly connected to the lower end of the pull rod 1 with a tapered fitting surface, and the lower threaded hole is threadedly connected to the first connecting rod 6.

[0016] Furthermore, a 20 mm deep avoidance groove is provided on the top surface of the upper blade 2 to prevent the pull rod 1 with a tapered mating surface from moving upward to the loading head when the pressure is transmitted.

[0017] Embodiment 2: The present application also discloses an operation method of a tension-compression bidirectional force transmission device, which is implemented by using a tension-compression bidirectional force transmission device described in Example 1, and comprises the following steps: Step 1: Prepare a bidirectional force transmission device for tension and compression, and ensure that the tie rod 1 with a tapered mating surface passes through the upper blade 2, the middle blade 3, and the lower blade 4 in sequence along the center and is threadedly fastened to the tie rod locking nut 5; when the upper blade 2, the middle blade 3, and the lower blade 4 are pressed, the inner and outer cone surfaces of the tie rod 1 with a tapered mating surface and the upper blade 2 are separated; connect the flange of the upper blade 2 to the loading head of the calibrated balance; Step 2: Drive the motor to rotate, so that the electric cylinder contracts, the middle blade 3 and the upper blade 2 gradually separate, and the pull rod 1 with the tapered mating surface moves downward until the tapered structure and the inner tapered hole are pressed together, and the output force value of the sensor is monitored at the same time. When the predetermined tensile load is reached, the motor stops running. At this time, the force transmitted by the tension and compression bidirectional force transmission device is the tensile force; Step three, drive the motor to rotate to make the electric cylinder extend, and the pull rod 1 with the tapered mating surface moves upward. The tapered surface and the inner tapered surface of the upper cutting edge 2 are gradually separated, and the middle cutting edge 3 and the upper cutting edge 2 are gradually compressed until they are tightly mated with the cutting edge of the lower cutting edge 4. At the same time, monitor the output force value of the sensor. When the predetermined compression load is reached, the motor stops running. At this time, the force transmitted by the tension and compression bidirectional force transmission device is the compression force.

[0018] Working principle and process: This application is mainly used for tension and compression bidirectional loading during wind tunnel balance calibration. The main structure is a pull rod with a conical surface combined with three knife edges. Its working principle is: when the tension and compression bidirectional force transmission device is subjected to tension, the knife edge structure separates, and the pull rod with a conical surface bears the force and transmits the tension to the calibrated balance. When the tension and compression bidirectional force transmission device is subjected to pressure, the pull rod with a conical mating surface separates from the connecting end, and the three knife edge structures are compressed together to transmit the pressure to the calibrated balance. Finally, a set of force transmission devices is used to complete the loading of positive and negative forces on the balance.

[0019] The above embodiments are merely illustrative of the principles and effects of the present application, and are not intended to limit the present application. Anything within the technical concept disclosed in the present application, and any simple replacement or change based on the technical solution of the present application, shall fall within the protection scope of the present application.

Claims

1. A tension and compression bidirectional force transmission device, characterized in that: It comprises a pull rod with a tapered mating surface (1), an upper cutting edge (2), a middle cutting edge (3), a lower cutting edge (4), a pull rod locking nut (5), a first connecting rod (6), a force sensor (7), a second connecting rod (8), a spring box (9), a third connecting rod (10), and an electric cylinder motor integrated body (11); The upper blade (2), the middle blade (3), and the lower blade (4) are coaxially arranged in sequence from top to bottom; a tie rod locking nut (5) is fixedly installed at the lower part of the lower blade (4); the tie rod (1) with a tapered fitting surface passes through the upper blade (2), the middle blade (3), and the lower blade (4) in sequence, and is threadedly connected to the tie rod locking nut (5); the tie rod (1) with a tapered fitting surface is coaxially arranged with the upper blade (2); the tie rod locking nut (5) is connected with the first connecting rod (6), the force sensor (7), the second connecting rod (8), the spring box (9), the third connecting rod (10), and the electric cylinder motor assembly (11) in sequence.

2. The tension and compression bidirectional force transmission device according to claim 1, characterized in that: The upper part of the pull rod with a tapered fitting surface (1) is a tapered structure, and the top surface of the pull rod with a tapered fitting surface (1) has an "I"-shaped groove; the upper end of the upper blade (2) is a flange structure end, and the flange structure end is connected to a loading head for wind tunnel balance calibration; an inner tapered hole is arranged inside the flange structure end, and the tapered structure cooperates with the inner tapered hole; the lower end of the upper blade (2), the upper and lower ends of the middle blade (3) and the upper end of the lower blade (4) are all blade structures; the blade structure of the middle blade (3) cooperates with the blade structure of the upper blade (2) and the blade structure of the lower blade (4) to transmit the clamping force; the upper end of the pull rod locking nut (5) is a flange structure, and the flange structure is fixedly mounted on the lower blade (4); the pull rod locking nut (5) has an upper threaded hole and a lower threaded hole, the upper threaded hole is threadedly connected to the lower end of the pull rod with a tapered fitting surface (1), and the lower threaded hole is threadedly connected to the first connecting rod (6).

3. The tension and compression bidirectional force transmission device according to claim 2 is characterized in that: A 20 mm deep avoidance groove is provided on the top surface of the upper blade (2).

4. An operating method of the tension and compression bidirectional force transmission device according to claim 3, characterized in that: The following steps are involved: Step 1: Prepare a bidirectional force transmission device for tension and compression, and ensure that the tie rod (1) with a tapered mating surface passes through the upper blade (2), the middle blade (3), and the lower blade (4) in sequence along the center and is threadedly fastened to the tie rod locking nut (5); when the upper blade (2), the middle blade (3), and the lower blade (4) are pressed, the inner and outer tapered surfaces of the tie rod (1) with a tapered mating surface and the upper blade (2) are separated; connect the flange of the upper blade (2) to the loading head of the calibrated balance; Step 2: The drive motor rotates to cause the electric cylinder to contract, the middle blade (3) and the upper blade (2) gradually separate, and the pull rod (1) with the tapered mating surface moves downward until the tapered structure and the inner tapered hole are mated and pressed together, while monitoring the output force value of the sensor. When the predetermined tensile load is reached, the motor stops running. At this time, the force transmitted by the tension-compression bidirectional force transmission device is a tensile force; Step 3: The drive motor rotates to extend the electric cylinder, and the pull rod (1) with the tapered mating surface moves upward. The tapered surface and the inner tapered surface of the upper blade (2) are gradually separated, and the middle blade (3) and the upper blade (2) are gradually compressed until they are tightly mated with the blade of the lower blade (4). At the same time, the output force value of the sensor is monitored. When the predetermined compression load is reached, the motor stops running. At this time, the force transmitted by the tension and compression bidirectional force transmission device is a compression force.

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