CN104729776B - piezoelectric actuator thrust force measuring device and measuring method - Google Patents

Abstract

A piezoelectric actuator thrust force measurement device and measurement method, the system includes an external frame, an actuating part arranged in the external frame, a force-sensitive part and a displacement control part arranged in the external frame and sequentially connected to the lower end of the actuating part , the piezoelectric actuator to be tested, the connecting parts of the actuator and the connecting spring, one end of the connecting spring is connected to the external frame, and the adjusting bolt is penetrated from the lower end of the external frame and connected to the connecting spring, which is used to adjust the position and actuation of the connecting spring The first displacement sensor and the second displacement sensor are respectively located outside the outer frame and placed on both sides of the displacement control part and connected to the input end of the controller, and the output end of the controller is connected to the actuating part; the present invention also The measuring method is disclosed; the present invention solves the problem that the thrust force of the current piezoelectric actuator cannot be measured, fills up the blank of measuring technology, and has the characteristics of high measuring precision, good stability and convenient use.

Description

Measuring device and method for thrust force of piezoelectric actuator

technical field

The invention relates to a measuring device, in particular to a thrust force measuring device and a measuring method of a piezoelectric actuator.

Background technique

In recent years, with the rapid development of micro-nano technology, micro-displacement piezoelectric actuators have been widely used in the technical fields of optics, electronics, aviation, aerospace, machinery manufacturing, medicine and genetic engineering. Due to the stiffness of the piezoelectric actuator itself, the output force of the actuator will vary with the output displacement: when the output displacement is 0, the external output force can reach the maximum value. At this time, the force on the actuator (which is numerically equal to the external output force) is called the blocking force (Blocking Force) of the actuator. This force is generally used to measure the ability of the actuator to output force. But there is no measurement system directly used to measure the blocking force of the actuator at present. This is because measuring the thrust force of the actuator requires the use of a force sensor, and the force sensor needs to obtain the force information of the force sensor by sensing the deformation of the sensitive element in the sensor. However, when the actuator is in the blocking state, it does not output external displacement, and at this time, the sensitive element of the load cell cannot be deformed to measure the output force of the actuator. Therefore, the current force sensor cannot be used to measure the blocking force (Blocking Force) of the piezoelectric actuator.

Contents of the invention

The purpose of the present invention is to fill the gap in the above-mentioned measurement technology, to provide a piezoelectric actuator thrust force measurement device and measurement method, which solves the problem that the current piezoelectric actuator thrust force cannot be measured, and has the advantages of high measurement precision, stable Good performance and easy to use.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A piezoelectric actuator thrust measuring device, comprising an external frame 1, an actuating part 2 arranged in the external frame 1, a force sensitive part 3 arranged in the external frame 1 and connected to the lower end of the actuating part 2 in sequence, The displacement control part 4, the piezoelectric actuator to be tested 11, the actuator connecting part 5 and the connecting spring 8, one end of the connecting spring 8 is connected to the external frame 1, and the adjusting bolt 9 is penetrated from the lower end of the external frame 1 and connected to the connecting spring 8. It is used to adjust the position of the connection spring 8 and connect and fix it with the actuator connection part 5. The force sensitive part 3 is provided with a first elastic element 12 and a second elastic element 13, and the first elastic element 12 is attached with The first strain gauge 16 and the second strain gauge 17, the second elastic element 13 is pasted with the third strain gauge 14 and the fourth strain gauge 15, the first strain gauge 16, the second strain gauge 17, the third strain gauge 14 and the fourth strain gauge 15 form a Whiston full bridge; the first displacement sensor 6 and the second displacement sensor 7 are respectively located outside the outer frame 1 and placed on both sides of the displacement control part 4, and the input end of the controller 10 is connected to the first The output end of the displacement sensor 6 and the second displacement sensor 7 is connected to the actuating part 2, and the actuating part 2 is controlled by the controller 10 to output linear displacement and force.

In the measurement method of the piezoelectric actuator thrust measuring device described above, before starting the measurement, the connecting spring 8 is first adjusted through the adjusting bolt 9, so that the connecting spring 8 is connected to the actuator connecting part at the lower end of the piezoelectric actuator 11 to be tested. 5 is fixedly connected to adapt to piezoelectric actuators with different sizes; during measurement, since the lower end of the piezoelectric actuator 11 to be tested has been fixed by the actuator connecting part 5, if the piezoelectric actuator 11 to be tested output displacement, which will be transmitted to the displacement control part 4 and measured by the first displacement sensor 6 and the second displacement sensor 7; when the thrust force of the piezoelectric actuator needs to be measured, the controller 10 collects the first displacement The displacement signals measured by the sensor 6 and the second displacement sensor 7, and output control signals to control the actuating part 2 to output linear displacement and force, and make the piezoelectric actuator 11 to be measured by applying pressure to the piezoelectric actuator 11 to be measured. The displacement remains at 0; when the actuating part 2 is working, the force sensitive part 3 will be deformed due to the output linear displacement and force, through the first elastic element 12 and the second elastic element 13 and the first elastic element attached to the elastic element. A strain gauge 16, a second strain gauge 17, a third strain gauge 14 and a fourth strain gauge 15, and the deformation is related to the output force of the actuator, through the first strain gauge 16, the second strain gauge 17, the third strain gauge The deformation measured by the strain gauge 14 and the fourth strain gauge 15 can calculate the force when the output displacement of the piezoelectric actuator is 0, that is, the thrust force.

The invention aims at the gap in measurement technology and solves the problem that the thrust force of piezoelectric actuators cannot be measured at present. It has the characteristics of high measurement precision, good stability and convenient use.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the measurement system of the present invention.

Fig. 2 is a perspective view of the measuring system of the present invention.

Fig. 3 is a working diagram of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figures 1 and 2, a piezoelectric actuator thrust measuring device of the present invention includes an external frame 1, an actuating part 2 arranged in the external frame 1, arranged in the external frame 1 and connected in sequence The force sensitive part 3 at the lower end of the actuating part 2, the displacement control part 4, the piezoelectric actuator 11 to be tested, the actuator connecting part 5 and the connecting spring 8, one end of the connecting spring 8 is connected to the outer frame 1, and the adjusting bolt 9 is connected to the external frame 1. The lower end of the outer frame 1 penetrates and connects the connecting spring 8, which is used to adjust the position of the connecting spring 8 and connect and fix it with the actuator connecting part 5. The first elastic element 12 and the second elastic element 3 are arranged on the force sensitive part 3. Element 13, a first strain gauge 16 and a second strain gauge 17 are attached to the first elastic element 12, a third strain gauge 14 and a fourth strain gauge 15 are attached to the second elastic element 13, the first strain gauge 16 , the second strain gauge 17, the third strain gauge 14 and the fourth strain gauge 15 form a Whiston full bridge; the first displacement sensor 6 and the second displacement sensor 7 are respectively located outside the outer frame 1 and placed on both sides of the displacement control part 4 On the side, the input end of the controller 10 is connected to the first displacement sensor 6 and the second displacement sensor 7, and the output end is connected to the actuating part 2, and the actuating part 2 is controlled by the controller 10 to output linear displacement and force.

As shown in Figure 3, the measurement method of the piezoelectric actuator thrust measuring device of the present invention, before starting the measurement, first adjust the connecting spring 8 by adjusting the bolt 9, so that the connecting spring 8 is connected to the piezoelectric actuator 11 to be tested. The actuator connection part 5 at the lower end is fixedly connected to adapt to piezoelectric actuators with different sizes; during measurement, since the lower end of the piezoelectric actuator 11 to be tested has been fixed by the actuator connection part 5, if the The piezoelectric actuator 11 outputs displacement, which will be transmitted to the displacement control part 4 and measured by the first displacement sensor 6 and the second displacement sensor 7; when it is necessary to measure the thrust force of the piezoelectric actuator, the The controller 10 collects the displacement signals measured by the first displacement sensor 6 and the second displacement sensor 7, and outputs a control signal to control the actuating part 2 to output linear displacement and force. By applying pressure to the piezoelectric actuator 11 to be measured, the The displacement of the piezoelectric actuator 11 remains at 0; when the actuating part 2 is working, due to the output linear displacement and force, the force sensitive part 3 will be deformed, through the first elastic element 12 and the second elastic element 13 and the pasting The first strain gauge 16, the second strain gauge 17, the third strain gauge 14 and the fourth strain gauge 15 above the elastic element, and the deformation is related to the output force of the actuator, through the first strain gauge 16, the second strain gauge The second strain gauge 17, the third strain gauge 14 and the fourth strain gauge 15 can measure the deformation to calculate the force when the output displacement of the piezoelectric actuator is 0, that is, the blocking force (Blocking force), the calculation formula is:

Among them, ε is the measured strain of the elastic sensitive element, b is the width of the elastic sensitive element, h is the thickness of the elastic sensitive element, l is the length of the elastic sensitive element, and E is the elastic modulus of the material used.

Claims (2)

1. The piezoelectric actuator thrust measuring device is characterized in that: it includes an external frame (1), an actuating part (2) arranged in the external frame (1), is arranged in the external frame (1) and connected in sequence The force sensitive part (3), the displacement control part (4), the piezoelectric actuator to be tested (11), the actuator connecting part (5) and the connecting spring (8) at the lower end of the actuating part (2) are connected One end of the spring (8) is connected to the outer frame (1), and the adjusting bolt (9) penetrates through the lower end of the outer frame (1) and connects to the connecting spring (8), which is used to adjust the position of the connecting spring (8) and the actuator The connecting parts (5) are connected and fixed, the force sensitive part (3) is provided with a first elastic element (12) and a second elastic element (13), and a first strain gauge is attached to the first elastic element (12) (16) and the second strain gauge (17), the third strain gauge (14) and the fourth strain gauge (15) are pasted on the second elastic element (13), the first strain gauge (16), the second The strain gauge (17), the third strain gauge (14) and the fourth strain gauge (15) form a Whiston full bridge; the first displacement sensor (6) and the second displacement sensor (7) are respectively located on the outer frame (1) Outside and placed on both sides of the displacement control part (4), the input end of the controller (10) is connected to the first displacement sensor (6) and the second displacement sensor (7), and the output end is connected to the actuating part (2). The component (2) is controlled by the controller (10) to output linear displacement and force. 2. The measuring method of the piezoelectric actuator thrust measuring device according to claim 1, characterized in that: before starting the measurement, the connecting spring (8) is first adjusted by the adjusting bolt (9), so that the connecting spring (8) is connected to the The actuator connecting part (5) at the lower end of the piezoelectric actuator (11) is fixedly connected to adapt to piezoelectric actuators with different sizes; during measurement, since the lower end of the piezoelectric actuator (11) to be tested has is fixed by the actuator connecting part (5), therefore, if the piezoelectric actuator to be measured (11) outputs a displacement, the displacement will be transmitted to the displacement control part (4) and controlled by the first displacement sensor (6) and The second displacement sensor (7) is measured; When it is necessary to measure the thrust force of the piezoelectric actuator, the displacement signal measured by the first displacement sensor (6) and the second displacement sensor (7) is collected by the controller (10), And output the control signal to control the actuating part (2) to output linear displacement and force, and keep the displacement of the piezoelectric actuator (11) to be measured at 0 by applying pressure to the piezoelectric actuator (11) to be measured; When the part (2) works, due to the output linear displacement and force, the force sensitive part (3) will be deformed, through the first elastic element (12) and the second elastic element (13) and the first elastic element attached to the elastic element A strain gauge (16), a second strain gauge (17), a third strain gauge (14) and a fourth strain gauge (15), and the deformation is related to the output force of the actuator, through the first strain gauge (16 ), the second strain gauge (17), the third strain gauge (14) and the fourth strain gauge (15) measure the deformation and can calculate the force when the output displacement of the piezoelectric actuator is 0, that is, the thrust force. The formula is: ${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; l</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; k</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; Ebh</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}{\mathrm{<span\; class="notranslate">\; 12</span>}\mathrm{<span\; class="notranslate">\; l</span>}}$ Among them, ε is the measured strain of the elastic sensitive element, b is the width of the elastic sensitive element, h is the thickness of the elastic sensitive element, l is the length of the elastic sensitive element, and E is the elastic modulus of the material used.