A linear displacement measuring device

Abstract

The present invention relates to the technical field of displacement measurement, and particularly relates to a linear displacement measurement device, which comprises a fixed seat and a measuring shaft capable of lifting and sliding on the fixed seat; a displacement measurement component for measuring the distance between the measuring shaft and a reference position is arranged on the fixed seat; and a lifting component is arranged on the fixed seat. When the present invention is used, it can enable the measuring head to provide a stable measurement for the object to be measured, and in addition to accurately measuring the size of the part, it can also prevent the surface deformation of the part to be measured.

Description

Technical Field

[0001] The present invention relates to the technical field of displacement measurement, and particularly relates to a linear displacement measurement device. Background Art

[0002] Grating linear displacement sensors are widely used in various precision dimension measurements. For the measurement of the dimensions of conventional mechanical parts, the traditional grating linear displacement sensor measurement device can well meet the basic application requirements.

[0003] Usually, the measurement device uses the self-weight of the linear sensor or a spring to apply a force to the measurement shaft, so as to obtain the necessary contact pressure (measurement force) of the measurement contact head on the measured part. The resulting measurement force is often relatively large (for example, more than 1 N) or, due to the force applied by the spring, the measurement force varies at different strokes.

[0004] However, in many special precision parts, such as thin and light parts, soft material parts, elastic parts, etc., an excessive measurement force will cause deformation of the structure or surface of the measured part, resulting in distortion of the measurement result. At the same time, the varying measurement force will also cause a serious loss of measurement repeatability accuracy. Summary of the Invention

[0005] The purpose of the present invention is to provide a linear displacement measurement device in view of the defects and deficiencies of the prior art.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A linear displacement measurement device of the present invention includes a fixed seat and a measuring shaft that can slide up and down on the fixed seat; a displacement measurement component for measuring the distance between the measuring shaft and a reference position is provided on the fixed seat; a lifting component is provided on the fixed seat.

[0008] Further, the lifting component can not only lift the measuring shaft upward but also provide a supporting force that is not sufficient to lift the measuring shaft.

[0009] Further, the lifting component includes a lifting seat that can slide on the fixed seat, a lifting mechanism for driving the lifting seat to move up and down, and a swing rod connected to the lifting seat.

[0010] Further, the rod body of the swing rod is rotatably connected to the lifting seat through a rotating shaft.

[0011] Further, a weight component is provided on the swing rod; a swing rod position detection component is provided on the fixed seat; the swing rod position detection component generates a signal when the detected inclination angle of the swing rod reaches a set value; the swing rod position detection component includes a lever position switch fixed on the lifting seat and a lever shutter provided on the rod body of the swing rod.

[0012] Further, the counterweight assembly includes an adjusting screw rod fixed on the swing rod and a counterweight block threadedly connected to the adjusting screw rod.

[0013] Further, the counterweight block is provided with a threaded hole; a locking bolt that presses against the adjusting screw rod is threadedly connected in the threaded hole.

[0014] Further, an upper limit switch is fixed on the fixed seat; a lifting limit shielding plate is fixed on the lifting seat.

[0015] Further, rollers are arranged on the measuring shaft; the roller bodies of the rollers press against the upper surface of the swing rod; the rollers are fixed on the measuring shaft through roller fixing seats.

[0016] Further, the displacement measurement assembly includes a grating plate fixed on the measuring shaft and a grating encoder fixed on the fixed seat; guide wheels are arranged on both side surfaces of the grating plate; the guide wheels are fixed on the encoder seat.

[0017] After adopting the above structure, the beneficial effects of the present invention are as follows: A linear displacement measurement device described in the present invention includes a fixed seat and a measuring shaft that can slide up and down on the fixed seat; a displacement measurement assembly for measuring the distance between the measuring shaft and a reference position is arranged on the fixed seat; a lifting assembly is arranged on the fixed seat. When using the present invention, a guide sleeve slidably connected to the measuring shaft is connected to the fixed seat; the fixed seat is composed of two vertical plates and multiple side plates fixed between the two vertical plates; the measuring shaft is lifted to the original position by the lifting assembly, and then a measured object is placed below the measuring head. The measuring shaft is slowly lowered through the lifting assembly until before the measuring head contacts the measured object, the supporting force received by the measuring shaft from the lifting assembly is always F, and this F is equal to the self-weight G of the measuring shaft. When the measuring head contacts the measured object, analyze the forces on the measuring shaft. The self-weight G of the measuring shaft, the supporting force f received by the measuring shaft from the lifting assembly, and the supporting force N from the measured object on the measuring shaft, the resultant force of the three is zero; when the supporting force f of the lifting assembly on the measuring shaft reaches a set value; measure the current displacement value through the displacement measurement assembly and compare it with the initial value to obtain the size of the measured object. It can enable the measuring head to provide a stable measurement for the measured object, and in addition to accurately measuring the size of the part, it can also prevent the surface of the measured part from deforming. Description of the Drawings

[0018] Figure 1 is the front view of the present invention;

[0019] Figure 2 is the top view of the present invention;

[0020] Figure 3 is the connection structure diagram of the lifting seat and the swing rod;

[0021] Figure 4It is a connection structure diagram of a grating plate, a measuring shaft and an encoder seat;

[0022] Explanation of reference numerals:

[0023] 1. Grating plate; 2. Guide wheel; 3. Grating encoder; 4. Lifting seat; 5. Roller; 6. Swing rod;

[0024] 7. Measuring shaft; 8. Guide sleeve; 9. Measuring head; 10. Guide rod; 11. Lead screw; 12. Side plate;

[0025] 13. Vertical plate; 14. Motor; 15. Counterweight; 16. Driving pulley; 17. Transmission belt;

[0026] 18. Driven pulley; 19. Upper limit switch; 20. Lever position switch;

[0027] 21. Lifting limit baffle; 22. Lever baffle; 23. Rotating shaft; 24. Adjusting lead screw;

[0028] 25. Locking bolt; 26. Roller fixing seat; 27. Encoder seat. Detailed implementation manners

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] As Figures 1 to 4 shown, a linear displacement measuring device according to the present invention includes a fixed seat and a measuring shaft 7 that can slide up and down on the fixed seat; a measuring head 9 is fixed to the bottom end of the measuring shaft 7: a displacement measuring component for measuring the distance between the measuring shaft 7 and a reference position is provided on the fixed seat; a lifting component is provided on the fixed seat; a guide sleeve 8 slidably connected to the measuring shaft 7 is connected to the fixed seat; the fixed seat is composed of two vertical plates 13 and a plurality of side plates 12 fixed between the two vertical plates 13; the measuring shaft 7 is lifted to the original position by the lifting component, and then the object to be measured is placed below the measuring head 9, and the measuring shaft 7 is slowly lowered by the lifting component until before the measuring head 9 contacts the object to be measured, the supporting force on the measuring shaft 7 by the lifting component is always F, and this F is equal to the self-gravity G of the measuring shaft 7. When the measuring head 9 contacts the object to be measured, the forces on the measuring shaft 7 are analyzed. The self-gravity G of the measuring shaft 7, the supporting force f on the measuring shaft 7 by the lifting component, and the supporting force N of the object to be measured on the measuring shaft 7, the resultant force of the three is zero; when the supporting force f of the lifting component on the measuring shaft 7 reaches a set value; the current displacement value is measured by the displacement measuring component and compared with the initial value to obtain the size of the object to be measured. It can enable the measuring head 9 to provide a stable measurement for the object to be measured, and in addition to accurately measuring the size of the part, it can also prevent the surface deformation of the part to be measured.

[0031] As a preferred embodiment of the present invention, the lifting component can not only lift the measuring shaft 7 upward but also provide a supporting force insufficient to lift the measuring shaft 7 for the measuring shaft 7; the lifting component can provide a supporting force f for the measuring shaft 7, and during the measurement process, the supporting force is less than the gravity G of the measuring shaft 7, and G - f is equal to the contact pressure of the measuring head 9 on the object to be measured; when measurement is not required, f is greater than G, and the measuring shaft 7 is lifted by a certain height.

[0032] As a preferred embodiment of the present invention, the lifting component includes a lifting seat 4 that can slide on the fixed seat, a lifting mechanism that drives the lifting seat 4 to move up and down, and a swing rod 6 connected to the lifting seat 4; the lifting mechanism includes a guide rod 10 fixed on the fixed seat, a lead screw 11 rotatably connected to the fixed seat, a motor 14 fixed on the fixed seat, a driving pulley 16 connected to the output end of the motor 14, a driven pulley 18 connected to the lead screw 11, and a transmission belt 17 tensioned between the driving pulley 16 and the driven pulley 18; a lead screw nut threadedly connected to the lead screw 11 is connected to the lifting seat 4, and the lifting seat 4 is slidably connected to the guide rod 10; after the motor 14 is started, the lead screw 11 is driven to rotate through the driving pulley 16, the transmission belt 17, and the driven pulley 18, and the swing rod 6 on the lifting seat 4 moves up and down along the axial direction of the guide rod 10.

[0033] As a preferred embodiment of the present invention, the rod body of the swing rod 6 is rotatably connected to the lifting seat 4 through a rotating shaft 23.

[0034] As a preferred embodiment of the present invention, a weight component is provided on the swing rod 6; a swing rod position detection component is provided on the fixed seat; the swing rod position detection component generates a signal when the inclination angle of the detection swing rod 6 reaches a set value; the swing rod position detection component includes a lever position switch 20 fixed on the lifting seat 4 and a lever shutter 22 provided on the rod body of the swing rod 6; a stopper is provided on the lifting seat 4. Since the swing rod 6 will tilt to the left in the initial state and press on this stopper, the stopper stops the swing rod 6 from tilting further to the left to ensure that enough supporting force can be provided for the measuring shaft 7; when the lever shutter 22 disengages from the sensing position of the lever position switch 20, the lever position switch 20 generates a signal, causing the lifting mechanism to stop moving. At this time, the moment provided by the swing rod 6 to the measuring shaft 7 is a known set value, indirectly determining the pressure of the measuring head 9 on the surface of the object to be measured.

[0035] As a preferred embodiment of the present invention, the weight component includes an adjusting lead screw 24 fixed on the swing rod 6 and a weight block 15 threadedly connected to the adjusting lead screw 24; by rotating the weight block 15 on the adjusting lead screw 24, the force arm of the weight block 15 is changed, and the moment of the swing rod 6 on the measuring shaft 7 is changed. Since the force arm of the swing rod 6 acting on the measuring shaft 7 is a fixed value, the force of the swing rod 6 on the measuring shaft 7 is indirectly adjusted, thereby adjusting the pressure of the measuring head 9 on the surface of the object to be measured.

[0036] As a preferred embodiment of the present invention, a threaded hole is provided on the counterweight block 15; a locking bolt 25 that presses against the adjusting screw rod 24 is threadedly connected in the threaded hole; the locking bolt 25 can further lock the counterweight block 15 on the adjusting screw rod 24 to prevent the counterweight block 15 from loosening.

[0037] As a preferred embodiment of the present invention, an upper limit switch 19 is fixed on the fixed seat; a lifting limit shielding plate 21 is fixed on the lifting seat 4; after the lifting limit shielding plate 21 shields the upper limit switch 19, the lifting device stops moving.

[0038] As a preferred embodiment of the present invention, rollers 5 are provided on the measuring shaft 7; the roller bodies of the rollers 5 press against the upper surface of the swing rod 6; the rollers 5 are fixed on the measuring shaft 7 through roller fixing seats 26; the number of the rollers 5 is two; the front end of the swing rod 6 is a U-shaped arm; the two rollers 5 respectively press against the two arms of the U-shaped arm.

[0039] As a preferred embodiment of the present invention, the displacement measurement assembly includes a grating plate 1 fixed on the measuring shaft 7 and a grating encoder 3 fixed on the fixed seat; guide wheels 2 are provided on both side surfaces of the grating plate 1; the guide wheels 2 are fixed on an encoder seat 27; the encoder seat 27 is fixed on the vertical plate 13, and the grating plate 1 is also a part of the measuring shaft 7. When calculating the gravity of the measuring shaft 7, the gravity of the grating plate 1 needs to be added. Specific Embodiment 1

[0041] A guide sleeve 8 is provided on the vertical plate 13 of the fixed seat. A measuring shaft 7 is slidably connected in the guide sleeve 8. A roller fixing seat 26 is fixed on the shaft body of the measuring shaft 7. Rollers 5 are provided on both sides of the roller fixing seat 26. A grating plate 1 is fixed at the top end of the measuring shaft 7. A grating encoder 3 is fixed through the encoder seat 27, and the displacement of the grating plate 1 can be measured. A guide rod 10 provided on the vertical plate 13, a lead screw 11 rotatably connected to the fixed seat, a motor 14 fixed on the fixed seat, a driving pulley 16 connected to the output end of the motor 14, a driven pulley 18 connected to the lead screw 11, and a transmission belt 17 tensioned between the driving pulley 16 and the driven pulley 18; a nut on the lifting seat 4 is threadedly connected to the lead screw 11, and the guide rod 10 is slidably connected to the lifting seat 4; a lifting limit shielding plate 21 is fixed on the lifting seat 4, and an upper limit switch 19 is fixed on the vertical plate 13; the rod body of the swing rod 6 is rotatably connected to the lifting seat 4 through a rotating shaft 23 to form a lever. One end of the lever abuts against the roller 5, and a counterweight block 15 is provided at the other end of the lever; a lever position switch 20 is provided on the lifting seat 4, and a lever shielding plate 22 is provided on the swing rod 6; a stop block is provided on the lifting seat 4.

[0042] Working principle: As Figure 1As shown, rollers 5 are provided on both sides of the roller fixing seat 26 and are pressed against the swing rod 6. After the swing rod 6 is limited by the stopper, it cannot continue to rotate counterclockwise. Therefore, when the probe 9 is not in contact with the object to be measured, it forms a support for the measuring shaft 7. After the motor 14 is started, the swing rod 6 on the lifting seat 4 is driven by the driving pulley 16, the transmission belt 17 and the driven pulley 18 to drive the screw rod 11 to rotate and descend along the axial direction of the guide rod 10. The grating plate 1, the swing rod 6 and the measuring shaft 7 move downward together. During the descent, the swing rod 6 does not move at all times; when the probe 9 just contacts the object to be measured, the probe 9 receives the supporting force of the object to be measured, but the lifting seat 4 still needs to continue to descend. Due to the action of the counterweight 15, the swing rod 6 does not separate from the roller 5 but is supported on the roller 5; so the swing rod 6 rotates clockwise, and the torque generated by the counterweight 15 acts on the roller 5, forming a pressure on the measuring shaft 7 in the direction perpendicular to the contact surface of the swing rod 6. The component of this pressure in the axial direction of the measuring shaft 7 is equal to its f, the total gravity of the measuring shaft 7 and the grating plate 1 is G, and the supporting force of the object to be measured on the measuring shaft 7 is N; when the swing rod 6 is in the horizontal state, the lever shutter 22 just disengages from the lever position switch 20, and the lever position switch 20 generates an electrical signal to stop the motor 14 and the swing rod 6 stops swinging. At this time, the supporting force of the swing rod 6 on the measuring shaft 7 is at the maximum value; and every time the swing rod 6 is in the horizontal position, the support of the swing rod 6 on the measuring shaft 7 is equal, and the measuring force at different strokes will not change either; the circuit components of the grating encoder 3 collect, amplify and perform AD conversion on the optoelectronic signal through the grating plate 1, convert it into a displacement digital value, and compare it with the data of the measurement reference surface to obtain the size of the measured part. After the measurement is completed, the motor 14 is started, and the swing rod 6 on the lifting seat 4 is driven by the driving pulley 16, the transmission belt 17 and the driven pulley 18 to drive the screw rod 11 to rotate and rise along the axial direction of the guide rod 10. The swing rod 6 swings counterclockwise until the swing rod 6 touches the stopper, then the swing rod 6 hangs the measuring shaft 7 and drives the measuring shaft 7 to rise until the lifting limit shutter 21 blocks the upper limit switch 19, and then the motor 14 stops rotating, completing a process.

[0043] The above is only the preferred embodiment of the present invention. Therefore, all equivalent changes or modifications made according to the structure, features and principles described in the scope of the present invention patent application are included in the scope of the present invention patent application.

Claims

1. A linear displacement measuring device, which comprises a fixed base and a measuring shaft (7) capable of lifting and sliding on the fixed base; characterized in that: A displacement measurement component for measuring the distance between the measuring shaft (7) and the reference position is provided on the fixed seat; a lifting component is provided on the fixed seat; the lifting component includes a lifting seat (4) capable of sliding on the fixed seat, a lifting mechanism for driving the lifting seat (4) to perform lifting motion, and a swing rod (6) connected to the lifting seat (4); a counterweight component is provided on the swing rod (6); a swing rod position detection component is provided on the fixed seat; the swing rod position detection component generates a signal when the inclination angle of the detection swing rod (6) reaches a set value; the swing rod position detection component includes a lever position switch (20) fixed on the lifting seat (4) and a lever shielding plate (22) provided on the rod body of the swing rod (6); the counterweight component includes an adjusting screw rod (24) fixed on the swing rod (6) and a counterweight block (15) threadedly connected to the adjusting screw rod (24); a threaded hole is provided on the counterweight block (15); a locking bolt (25) that presses against the adjusting screw rod (24) is threadedly connected in the threaded hole.

2. The linear displacement measuring device according to claim 1, wherein: In addition to being able to lift the measuring shaft (7) upward, the lifting component can also provide a supporting force that is not sufficient to lift the measuring shaft (7).

3. The linear displacement measuring device according to claim 2, wherein: The rod body of the swing rod (6) is rotatably connected to the lifting seat (4) through a rotating shaft (23).

4. A linear displacement measuring device according to claim 1, characterized in that: An upper limit switch (19) is fixed on the fixed seat; a lifting limit shielding plate (21) is fixed on the lifting seat (4).

5. A linear displacement measuring device according to claim 1, characterized in that: A roller (5) is provided on the measuring shaft (7); the wheel body of the roller (5) presses against the upper surface of the swing rod (6); the roller (5) is fixed on the measuring shaft (7) through a roller fixing seat (26).

6. A linear displacement measuring device according to claim 1, characterized in that: The displacement measurement component includes a grating plate (1) fixed on the measuring shaft (7) and a grating encoder (3) fixed on the fixed seat; guide wheels (2) are provided on both side surfaces of the grating plate (1); the guide wheels (2) are fixed on an encoder seat (27).

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