A span measuring instrument

Abstract

The invention discloses a cross-rod distance measuring instrument, comprising an upper box body and a lower box body, a control screen and two groups of detection units with the same structure; each group of detection units comprises a worm, a first bearing seat, a first motor, a worm wheel, a first lead screw, a second motor, a second bearing seat, a second lead screw, a slider, a probe connecting rod and a probe; the control screen controls the operation of the first motor and the second motor; the operation of the first motor enables the first lead screw to move in the vertical direction to adjust the height of the probe; the operation of the second motor enables the slider to move in the horizontal direction to adjust the distance between the probe and the flexible wheel. The invention can improve the efficiency and accuracy of the flexible wheel cross-rod distance detection, so that the combination of the rigid wheel, the flexible wheel and the cam in the assembly and matching of the harmonic reducer is more in line with the design requirements, and the assembly efficiency of the harmonic reducer and the stability of the performance of the harmonic reducer are improved.

Description

Technical Field

[0001] The invention relates to the field of harmonic reducers, and in particular to a span-rod distance measuring instrument for a flexible wheel in a harmonic reducer. Background Art

[0002] Harmonic reducer is a kind of high-precision reducer, which is now mostly used in high-precision instruments. Harmonic reducer has the characteristics of high precision, simple structure and large transmission ratio. Among the harmonic reducers, the flexible wheel, the rigid wheel and the cam are the three most critical components. The sizes of these three components must match each other to achieve the best performance of the harmonic reducer. Among them, the flexible wheel is a thin-walled part, which will be deformed after assembly. In order to avoid interference, the flexible wheel teeth must be axially modified, so the span of the flexible wheel teeth at each position in the axial direction is different. Therefore, when measuring the span of the flexible wheel, the skills and experience of the inspectors are required to be high. If the measuring tool is not level enough or the measurement position is wrong, the measurement result will be greatly deviated, resulting in poor coordination between the flexible wheel and the rigid wheel during assembly and selection, affecting the performance of the harmonic reducer. In addition, when inspecting, it will take a lot of time for the inspectors to find the correct position and level, which affects the efficiency.

[0003] In addition, the measuring part of the current probe for measuring the cross-rod distance is mostly spherical. However, since the teeth of the harmonic flexible wheel are very small, the ball diameter of the measuring part is also very small. The connection between the measuring part and the probe is very weak and can easily break during use. Moreover, the probe with such a small-diameter ball head is expensive, which increases the manufacturing cost of the product. Summary of the invention

[0004] In order to solve the problems mentioned in the above background technology, the present invention provides a cross-rod distance measuring instrument, comprising an upper box body and a lower box body, a control panel and two groups of detection units with the same structure;

[0005] The two groups of detection units are symmetrically arranged on the lower box; each group of detection units includes a worm, a first bearing seat, a first motor, a worm wheel, a first lead screw, a second motor, a second bearing seat, a second lead screw, a slider and a probe; the upper box is arranged on the upper surface of the lower box, and the upper box is symmetrically provided with an upper box containing cavity matching the two groups of detection units; the upper box containing cavity provides space and protection for the up and down movement of the first lead screw; the upper surface of the upper box is also provided with a three-jaw chuck for placing a flexible wheel;

[0006] One end of the worm is mounted on the lower housing through a bearing, and the other end of the worm is connected to the first bearing seat through a bearing, and the first bearing seat is mounted on the lower housing through screws; the first motor is mounted on the first bearing seat through screws and connected to the worm; the worm wheel is mounted on the lower housing through a bearing and meshes with the worm; the inner hole of the worm wheel is provided with an internal thread, the outer diameter of the first lead screw is provided with an external thread, the first lead screw is sleeved in the inner hole of the worm wheel, and the external thread of the first lead screw matches the internal thread of the worm wheel;

[0007] The second motor is installed on the top of the first screw by screws; the outer diameter of the second screw is provided with an external thread, the slider is provided with an inner hole, the inner hole of the slider is provided with an internal thread, and the external thread of the second screw matches the internal thread of the slider; the second screw is installed on the second bearing seat through a bearing, the second bearing seat is fixed to the top of the first screw by screws, and the second screw is connected to the second motor by transmission; the slider is provided with a probe connecting rod, and the probe is fixed at the end of the probe connecting rod.

[0008] The top of the first lead screw is a platform for fixing the second bearing seat.

[0009] As a preferred embodiment of the present invention, the two groups of detection units operate synchronously, and the first motors of the two groups of detection units are controlled by the same group of buttons in the control panel. This group has two buttons, respectively marked as up and down. When the buttons are pressed, the first motors of the two groups of detection units operate synchronously at the same time, ensuring that the first lead screws of the two groups of detection units can move longitudinally synchronously; the second motors of the two groups of detection units are controlled by the same group of buttons in the control panel. This group has two buttons, respectively marked as left and right. When the buttons are pressed, the second motors of the two groups of detection units operate synchronously at the same time, ensuring that the second lead screws of the two groups of detection units can move laterally synchronously.

[0010] As a preferred embodiment of the present invention, after the cross-rod distance measuring instrument is installed, the two probes are in contact with each other, the initial position is set to 0, the rotation speed of the second motor is stable, and it is connected to the control screen through a connecting line. The connecting line transmits the data of the number of turns of the motor each time it runs to the control screen. The control screen calculates the horizontal movement distance of the second lead screw after each operation of the second motor based on the circle data of the motor and the pitch of the second lead screw, thereby obtaining the distance between the two probes and displaying it on the control screen to indicate the cross-rod distance; the control screen will take into account the distance that the probes are retracted when calculating the distance between the two probes to obtain an accurate cross-rod distance.

[0011] As a preferred embodiment of the present invention, the two ends of the worm are on the same horizontal plane. An inner hole is provided in the probe connecting rod, and an inner thread is provided in the inner hole of the probe connecting rod. The probe is provided with an outer thread. The probe is connected and fixed to the probe connecting rod on the slider through the thread, so that the probe can be easily replaced. The measuring part of the probe is conical in shape. The conical measuring part has low cost and will not be easily broken. The generatrix angle of the cone of the probe is the same as the pressure angle of the measured flexible wheel teeth, ensuring that the measuring part of the probe is completely in contact with the flexible wheel teeth during measurement. This can ensure that the measuring part is completely in contact with the flexible wheel teeth during measurement, thereby improving the measurement accuracy.

[0012] The probe connecting rod is used to connect the probe and one end of the probe is provided with an elastic telescopic shell. The slider, the probe connecting rod and the probe form a contact sensor. When the probe contacts the flexible wheel teeth, the probe will retract. The retraction action of the probe will generate a signal, which is transmitted to the control panel through the connecting line. The control panel will control the second motor to stop, which can prevent the probe from hitting the flexible wheel, causing damage to the probe and deformation of the flexible wheel, thereby ensuring the accuracy of the measurement results.

[0013] As a preferred embodiment of the present invention, the three-jaw chuck is arranged between the two containing cavities of the upper box body and the center of the three-jaw chuck is in the same plane as the center of the sphere of the probe; when the flexible wheel is placed on the three-jaw chuck and clamped, the center of the flexible wheel is also in the same plane as the center of the sphere of the probe, so that when measuring, the probe measures the opposite side teeth of the flexible wheel, which saves the time of finding the opposite side teeth of the flexible wheel and improves the detection efficiency.

[0014] As a preferred solution of the present invention, the lower box body is provided with a concave cavity, and the two groups of detection units are symmetrically arranged in the concave cavity of the lower box body.

[0015] The present invention can improve the efficiency and accuracy of the detection of the span of the flexible wheel, so that the combination of the rigid wheel, the flexible wheel and the cam during the assembly and matching of the harmonic reducer can better meet the design requirements, thereby improving the assembly efficiency of the harmonic reducer and the stability of the performance of the harmonic reducer. The measuring part of the probe used in the present invention is conical in shape, the conical measuring part is low in cost and will not easily break and damage, and the generatrix angle of the cone is the same as the pressure angle of the flexible wheel teeth to be measured, so that the measuring part can be completely fitted with the flexible wheel teeth during measurement, thereby improving the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the external structure of the present invention;

[0017] Figure 2 It is a schematic diagram of the external structure of the present invention;

[0018] Figure 3 It is a schematic diagram of the internal structure of the present invention;

[0019] Figure 4It is a schematic diagram of the local structure of the present invention;

[0020] Figure 5 It is a cross-sectional view of the internal structure of the present invention.

[0021] In the figure: 1. upper box; 1-1. upper box cavity; 2. lower box; 3. control panel; 4. three-jaw chuck; 5. flexible wheel; 6. worm; 7. first bearing seat; 8. first motor; 9. worm wheel; 10. first lead screw; 11. second motor; 12. second bearing seat; 13. second lead screw; 14. slider; 15. probe connecting rod; 16. probe. DETAILED DESCRIPTION

[0022] The present invention is further described and illustrated below in conjunction with specific embodiments. The embodiments are merely exemplary of the present disclosure and do not define the scope of limitation. The technical features of each embodiment of the present invention may be combined accordingly without conflicting with each other.

[0023] A cross-rod distance measuring instrument comprises an upper box body 1 and a lower box body 2, a control panel 3 and two groups of detection units with the same structure;

[0024] like Figure 5 As shown, the lower box body 2 is provided with a concave cavity, and the two groups of detection units are symmetrically arranged in the concave cavity of the lower box body 2; each group of detection units includes a worm 6, a first bearing seat 7, a first motor 8, a worm wheel 9, a first screw 10, a second motor 11, a second bearing seat 12, a second screw 13, a slider 14 and a probe 16; the upper box body 1 is arranged on the upper surface of the lower box body 2, as shown in FIG. Figure 1 As shown, the upper box body 1 is symmetrically provided with an upper box body containing cavity 1-1 matching the two sets of detection units; the upper box body containing cavity 1-1 provides space and protection for the up and down movement of the first lead screw 10; the upper surface of the upper box body 1 is also provided with a three-jaw chuck 4 for placing the flexible wheel 5;

[0025] like Figure 3 As shown, one end of the worm 6 is mounted on the lower housing 2 through a bearing, and the other end of the worm 6 is connected to the first bearing seat 7 through a bearing, and the first bearing seat 7 is mounted on the lower housing 2 through screws; the first motor 8 is mounted on the first bearing seat 7 through screws and connected to the worm 6; the worm wheel 9 is mounted on the lower housing 2 through a bearing and meshes with the worm 6; the inner hole of the worm wheel 9 is provided with an internal thread, and the outer diameter of the first lead screw 10 is provided with an external thread, the first lead screw 10 is sleeved in the inner hole of the worm wheel 9, and the external thread of the first lead screw 10 matches the internal thread of the worm wheel 9;

[0026] like Figure 4As shown, the second motor 11 is installed on the top of the first screw 10 by screws; the outer diameter of the second screw 13 is provided with an external thread, the slider 14 is provided with an inner hole, the inner hole of the slider 14 is provided with an internal thread, and the external thread of the second screw 13 matches the internal thread of the slider 14; the second screw 13 is installed on the second bearing seat 12 through a bearing, the second bearing seat 12 is fixed to the top of the first screw 10 by screws, and the second screw 13 is connected to the second motor 11 in transmission; the slider 14 is provided with a probe connecting rod, and the probe 16 is fixed at the end of the probe connecting rod.

[0027] The first motor 8 and the second motor 11 are connected to the control panel 3 through a control line. The control panel 3 controls the operation of the first motor 8 and the second motor 11. The control panel 3 is installed on the upper surface of the upper box body 1. The operation of the first motor 8 enables the first lead screw 10 to move in the vertical direction to adjust the height of the probe 16, and the height of the probe 16 is displayed on the control panel 3. The operation of the second motor 11 enables the slider 14 to move in the horizontal direction to adjust the distance between the probe 16 and the flexible wheel 5, and the distance between the probe 16 and the flexible wheel 5 is displayed on the control panel 3 to indicate the cross-rod distance. The two groups of detection units operate synchronously, and the first motors of the two groups of detection units are controlled by the same group of buttons in the control panel. This group has two buttons, marked as up and down respectively. When the buttons are pressed, the first motors of the two groups of detection units operate synchronously at the same time, ensuring that the first lead screws of the two groups of detection units can move synchronously longitudinally; the second motors of the two groups of detection units are controlled by the same group of buttons in the control panel. This group has two buttons, marked as left and right respectively. When the buttons are pressed, the second motors of the two groups of detection units operate synchronously at the same time, ensuring that the second lead screws of the two groups of detection units can move synchronously laterally.

[0028] The two ends of the worm 6 are on the same horizontal plane. An inner hole is provided in the probe connecting rod, and the inner hole of the probe connecting rod is provided with an internal thread. The probe 16 is provided with an external thread. The probe 16 is connected and fixed to the probe connecting rod on the slider 14 through a thread. The top of the first screw 10 is a platform for fixing the second bearing seat 12. The probe 16 is connected and fixed to the probe connecting rod 15 on the slider 14 through a thread, so that the probe 16 can be easily replaced. The measuring part of the probe 16 is conical in shape. The conical measuring part has low cost and will not be easily broken. The generatrix angle of the cone of the probe is the same as the pressure angle of the measured flexible wheel teeth, ensuring that the measuring part of the probe is completely in contact with the flexible wheel teeth during measurement. This can ensure that the measuring part is completely in contact with the flexible wheel teeth during measurement, thereby improving the measurement accuracy.

[0029] The probe connecting rod is used to connect the probe, and one end of the probe is provided with an elastic telescopic housing. The slider, the probe connecting rod and the probe form a contact sensor. When the probe contacts the flexible wheel teeth, the probe will retract, and the retracting action of the probe will generate a signal. The signal is transmitted to the control panel through the connecting line, and the control panel will control the second motor to stop, so as to prevent the probe from hitting the flexible wheel, causing damage to the probe and deformation of the flexible wheel, thereby ensuring the accuracy of the measurement result.

[0030] After the cross-rod distance measuring instrument is installed, the two probes are in contact with each other, the initial position is set to 0, the speed of the second motor is stable, and the second motor is connected to the control screen through a connecting line. The connecting line transmits the data of the number of turns of the motor each time to the control screen. The control screen calculates the horizontal movement distance of the second lead screw after each operation of the second motor according to the motor turn data and the pitch of the second lead screw, thereby obtaining the distance between the two probes and displaying it on the control screen to indicate the cross-rod distance; when the probe (16) contacts the flexible wheel teeth, the probe (16) will retract 0.01 mm. When the sensor receives the movement of the probe (16) retracting, it will transmit the signal to the control screen (3) through the connecting line. The control screen (3) will control the second motor (11) to stop, so as to prevent the probe from hitting the flexible wheel, causing damage to the probe (16) and deformation of the flexible wheel (5), thereby ensuring the accuracy of the measurement result. When calculating the distance between the two probes, the control screen will take into account the 0.01 mm distance of the probe retraction to obtain an accurate cross-rod distance.

[0031] like Figure 2 As shown, the three-jaw chuck 4 is arranged between the two containing cavities of the upper box body 1 and the center of the three-jaw chuck 4 is in the same plane as the center of the sphere of the probe 16; when the flexible wheel 5 is placed on the three-jaw chuck 4 and clamped, the center of the flexible wheel 5 is also in the same plane as the center of the sphere of the probe 16, so that when measuring, the probe measures the opposite side teeth of the flexible wheel 5, which saves the time of finding the opposite side teeth of the flexible wheel and improves the detection efficiency.

[0032] Example 1

[0033] The flexible wheel 5 is placed on the three-jaw chuck 4 and clamped. A group of buttons marked as up and down are set in the control screen 3 to control the first motors 8 of the two detection units to run synchronously at the same time. The first motor 8 rotates to drive the worm 6 to rotate. The worm 6 engages with the turbine 9 to rotate the turbine 9. The internal thread of the turbine 9 and the first lead screw 10 produce relative motion, so that the first lead screws 10 of the two detection units can move longitudinally synchronously. At the same time, the height value of the probe 16 will be displayed on the control screen 3, so that the probe 16 is adjusted to the designed measurement height of the flexible wheel 5. Then, through a group of buttons marked as left and right in the control panel 3, the second motors 11 of the two detection units are controlled to rotate to drive the second lead screws 13 of the two detection units to rotate. The second lead screws 13 and the internal threads of the slider 14 produce relative motion, so that the sliders 14 of the two detection units can move synchronously horizontally, so that the probe 16 touches the teeth of the flexible wheel 5 to measure the cross-rod distance. When the probe 16 touches the flexible wheel teeth, the probe 16 will retract 0.01mm, and the retraction action of the probe 16 will generate a signal, which is transmitted to the control panel 3 through the connecting line. The control panel 3 controls the second motor 11 to stop rotating, so as to prevent the probe 16 from hitting the flexible wheel 5, causing damage to the probe 16, and deformation of the flexible wheel 5, thereby ensuring the accuracy of the measurement results. At the same time, the distance between the two probes 16 will be displayed on the control panel 3, and the 0.01mm distance of the probe retraction will be considered and displayed on the internal control panel 3 to represent the value of the cross-rod distance, so as to obtain the cross-rod distance of the flexible wheel 5.

[0034] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A span measuring instrument, characterized in that: It comprises an upper box body (1), a lower box body (2), a control panel (3) and two groups of detection units with the same structure; Two groups of detection units are symmetrically arranged on the lower box body (2); each group of detection units comprises a worm (6), a first bearing seat (7), a first motor (8), a worm wheel (9), a first lead screw (10), a second motor (11), a second bearing seat (12), a second lead screw (13), a slider (14), a probe connecting rod (15) and a probe (16); The upper box body (1) is arranged on the upper surface of the lower box body (2), and the upper box body (1) is symmetrically provided with upper box body containing cavities (1-1) matching the two groups of detection units; the upper box body containing cavity (1-1) provides space and protection for the up and down movement of the first lead screw (10); the upper surface of the upper box body (1) is also provided with a three-jaw chuck (4) for placing the flexible wheel (5) to be tested; the three-jaw chuck (4) is arranged between the two containing cavities of the upper box body (1), and the center of the three-jaw chuck (4) and the center of the sphere of the probe (16) are on the same plane; One end of the worm (6) is mounted on the lower housing (2) via a bearing, and the other end of the worm (6) is connected to a first bearing seat (7) via a bearing, and the first bearing seat (7) is mounted on the lower housing (2); the first motor (8) is mounted on the first bearing seat (7) and connected to the worm (6); the worm wheel (9) is mounted on the lower housing (2) via a bearing and meshes with the worm (6); the inner hole of the worm wheel (9) is provided with an internal thread, the outer diameter of the first lead screw (10) is provided with an external thread, the first lead screw (10) is vertically sleeved in the inner hole of the worm wheel (9), and the external thread of the first lead screw (10) matches the internal thread of the worm wheel (9); The second motor (11) is mounted on the top of the first lead screw (10); the second lead screw (13) is provided with an external thread, the slider (14) is provided with an inner hole with an internal thread, and the external thread of the second lead screw (13) matches the internal thread of the slider (14); the second lead screw (13) is mounted on the second bearing seat (12) via a bearing, the second bearing seat (12) is fixed on the top of the first lead screw (10), and the second lead screw (13) is transmission-connected to the second motor (11); a probe connecting rod is horizontally arranged on the slider (14), and the probe (16) is fixed at the end of the probe connecting rod (15); The first motor (8) and the second motor (11) are connected to the control panel (3) via control lines; The two detection units are operated synchronously. The first motors (8) of the two detection units are controlled by the same set of buttons in the control panel (3). The set has two buttons, marked as up and down respectively. When the buttons are pressed, the first motors (8) of the two detection units are operated synchronously at the same time, ensuring that the first lead screws (10) of the two detection units can move longitudinally synchronously. The second motors (11) of the two detection units are controlled by the same set of buttons in the control panel (3). The set has two buttons, marked as left and right respectively. When the buttons are pressed, the second motors (11) of the two detection units are operated synchronously at the same time, ensuring that the second lead screws (13) of the two detection units can move laterally synchronously. The probe connecting rod is provided with an inner hole, the inner hole of the probe connecting rod is provided with an inner thread, the probe (16) is provided with an outer thread, and the probe (16) is connected and fixed to the probe connecting rod via the thread; the measuring portion of the probe (16) is in the shape of a cone, the generatrix angle of the cone of the probe is the same as the pressure angle of the flexspline tooth to be measured, so as to ensure that the measuring portion of the probe (16) is completely fitted with the flexspline tooth during measurement.

2. A span distance measuring instrument according to claim 1, characterized in that: The two ends of the worm (6) are on the same horizontal plane.

3. A span distance measuring instrument according to claim 1, characterized in that: An elastic telescopic housing is provided at one end of the probe connecting rod (15) for connecting to the probe (16); the slider (14), the probe connecting rod (15) and the probe (16) form a contact sensor and are connected to the control panel (3) via wiring.

4. A span distance measuring instrument according to claim 1, characterized in that: The top of the first lead screw (10) is a platform for fixing the second bearing seat (12).

5. A span distance measuring instrument according to claim 1, characterized in that: The control panel (3) is mounted on the upper surface of the upper box body (1).

6. A span distance measuring instrument according to claim 1, characterized in that: The upper surface of the lower box body (2) is provided with a concave cavity, and the two groups of detection units are symmetrically arranged in the concave cavity of the lower box body (2).

7. A span distance measuring instrument according to claim 3, characterized in that: After the cross-bar distance measuring instrument is installed, the two probes (16) are in contact with each other, the initial position is set to 0, the speed of the second motor (11) is stable, and the second motor (11) is connected to the control screen (3) through a connecting line. The connecting line transmits the data of the number of revolutions of the motor in each operation to the control screen (3). The control screen (3) calculates the horizontal movement distance of the second lead screw (13) after each operation of the second motor (11) according to the revolution data of the motor and the pitch of the second lead screw (13), thereby obtaining the distance between the two probes and displaying it on the control screen (3) to indicate the cross-bar distance; when the probe (16) contacts the flexible wheel teeth, the probe (16) will retract, and when the sensor receives the movement of the probe (16) retracting, it will transmit a signal to the control screen (3) through the connecting line, and the control screen (3) will control the second motor (11) to stop; when calculating the distance between the two probes, the control screen (3) will take the retracted distance of the probe (16) into consideration to obtain an accurate cross-bar distance.

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