Drawing force testing mechanism and method for ball spline shaft

Abstract

The invention relates to the technical field of drawing force testing, in particular to a drawing force testing mechanism and method for a ball spline shaft. The drawing force testing mechanism comprises a tray, a first clamp and a second clamp; the second clamp can move relative to the first clamp so as to realize drawing of the ball spline shaft; an outer shaft clamping jaw and a floating mechanism are arranged on the second clamp, and the second clamp clamps the outer shaft through the outer shaft clamping jaw; when the first clamp and the outer shaft clamping jaw clamp the inner shaft and the outer shaft respectively, the outer shaft clamping jaw can move in the moving direction perpendicular to the second clamp through the floating mechanism so as to keep the inner shaft and the outer shaft in a coaxial state. The drawing force testing method is applied to the drawing force testing mechanism. After the inner shaft and the outer shaft are clamped by the first clamp and the second clamp respectively, the axis of the outer shaft is corrected through the floating mechanism, so that the inner shaft and the outer shaft are kept in a coaxial state, the drawing force of the ball spline shaft is tested, and the test accuracy can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of drawing force testing, and more specifically, to a drawing force testing mechanism and method for a ball spline shaft. Background Art

[0002] When testing the moving force of the inner shaft of a ball spline shaft within the outer shaft raceway, in a turntable, the positioning accuracy of the tray is not high. When the turntable transports the outer shaft to the detection station, the inner shaft and outer shaft of the ball spline shaft are not concentric with the two jaws of the drawing force testing mechanism, which has a certain impact on the measurement and monitoring of the drawing force. Summary of the Invention

[0003] In view of the above problems existing in the prior art, the present invention provides a drawing force testing mechanism and method for a ball spline shaft.

[0004] To solve the above technical problems, the present invention is solved by the following technical solutions:

[0005] In a first aspect, a drawing force testing mechanism for a ball spline shaft is provided, which includes a tray for supporting the ball spline shaft, and a first fixture and a second fixture respectively arranged on both sides of the tray;

[0006] The first fixture and the second fixture are respectively used for clamping the inner shaft and the outer shaft of the ball spline shaft, and the second fixture is movable relative to the first fixture to achieve the drawing of the ball spline shaft;

[0007] An outer shaft jaw and a floating mechanism are arranged on the second fixture, and the second fixture clamps the outer shaft through the outer shaft jaw;

[0008] When the first fixture and the outer shaft jaw respectively clamp the inner shaft and the outer shaft, the outer shaft jaw can move through the floating mechanism in a direction perpendicular to the moving direction of the second fixture to keep the inner shaft and the outer shaft in a coaxial state.

[0009] Preferably, both the first fixture and the second fixture are arranged on the test device body; a driving device connected to the first fixture and / or the second fixture is also arranged on the test device body to realize the relative movement of the first fixture and the second fixture.

[0010] Preferably, the second fixture further includes a pneumatic jaw that cooperates with the outer shaft jaw for clamping.

[0011] Preferably, the floating mechanism is a crossed roller guide.

[0012] Preferably, both the outer shaft jaw and the pneumatic jaw are arranged on the side of the crossed roller guide facing the first fixture.

[0013] Preferably, the second fixture further includes a centering cylinder disposed on a side of the crossed roller guide rail away from the first fixture; a through hole is provided on the crossed roller guide rail;

[0014] When the output shaft of the centering cylinder extends into the through hole, the crossed roller guide rail is limited in a direction perpendicular to the moving direction of the second fixture; when the output shaft of the centering cylinder moves out of the through hole, the crossed roller guide rail can move in a direction perpendicular to the moving direction of the second fixture to adjust the axis of the outer shaft to be coaxial with the axis of the inner shaft.

[0015] Preferably, a tension and compression sensor is provided at the first fixture and / or the second fixture.

[0016] In a second aspect, a method for testing the pulling force of a ball spline shaft is provided, which is applied to the above pulling force testing mechanism, and includes

[0017] Clamping the inner shaft and the outer shaft of the ball spline shaft by the first fixture and the second fixture respectively;

[0018] When the inner shaft and the outer shaft are not coaxial, adjusting the axis of the outer shaft through the floating mechanism on the second fixture; when the inner shaft and the outer shaft are coaxial, driving the first fixture and the second fixture to move away from each other to test the pulling force between the inner shaft and the outer shaft.

[0019] Preferably, adjusting the axis of the outer shaft through the floating mechanism on the second fixture specifically includes

[0020] Driving the second fixture to move closer to the first fixture to release the limit of the floating mechanism by the centering cylinder.

[0021] Preferably, after the second fixture adjusts the axis of the outer shaft through the floating mechanism, driving the second fixture to move away from the first fixture to limit the floating mechanism by the centering cylinder.

[0022] The present invention has at least the following beneficial effects:

[0023] Through the mutual cooperation of the first fixture, the second fixture and the floating mechanism, the present application can, after the first fixture and the second fixture clamp the inner shaft and the outer shaft respectively, correct the axis of the outer shaft through the floating mechanism to keep the inner shaft and the outer shaft in a coaxial state, and then perform a pulling force test on the ball spline shaft, which can preferably improve the accuracy of the test. Description of the Drawings

[0024] Figure 1 Shows a schematic diagram of the pulling force testing mechanism in some embodiments of the present application;

[0025] Figure 2 shows Figure 1 The partial enlarged view at position A in

[0026] Figure 3 shows the schematic diagram of the crossed roller guide and the centering cylinder in some embodiments of the present application;

[0027] Figure 4 shows the partial structural schematic diagram of the crossed roller guide in some embodiments of the present application;

[0028] Figure 5 shows the partial cross-sectional view of the drawing force testing mechanism in some embodiments of the present application;

[0029] Figure 6 shows the partial cross-sectional view of the drawing force testing mechanism with the centering cylinder hidden in some embodiments of the present application;

[0030] Figure 7 shows the flowchart of the drawing force testing method in some embodiments of the present application.

[0031] The names of the parts referred to by each numerical label in the drawings are as follows:

[0032] 100, ball spline shaft; 110, inner shaft; 120, outer shaft; 200, test device body; 210, first fixture; 220, second fixture; 221, outer shaft jaw; 222, crossed roller guide; 222a, support plate; 222b, ball guide; 222c, through hole; 223, air gripper; 224, centering cylinder; 230, tray; 240, driving device. Detailed implementation manners

[0033] To further understand the content of the present invention, the present invention will be described in detail with reference to the drawings and embodiments. It should be understood that the embodiments are only for explaining the present invention rather than limiting it.

[0034] In the first aspect, as shown in Figures 1-6 , this embodiment provides a drawing force testing mechanism for a ball spline shaft 100, including a first fixture 210, a second fixture 220 and a tray 230. Among them, the tray 230 is used to support the ball spline shaft 100. The first fixture 210 and the second fixture 220 are respectively arranged on both sides of the tray 230, and the first fixture 210 can clamp the inner shaft 110 of the ball spline shaft 100, and the second fixture 220 can clamp the outer shaft 120 of the ball spline shaft 100. Further, the second fixture 220 can move relative to the first fixture 210, and when the second fixture 220 moves away from the first fixture 210, a drawing force test can be performed between the inner shaft 110 and the outer shaft 120.

[0035] In order to improve the accuracy of the drawing force test between the inner shaft 110 and the outer shaft 120, an outer shaft jaw 221 and a floating mechanism are provided on the second fixture 220. Among them, the second fixture 220 clamps the outer shaft 120 through the outer shaft jaw 221. And when the first fixture 210 and the second fixture 220 clamp the ball spline shaft 100, the floating mechanism can correct the axis of the outer shaft 120 so that the axis of the outer shaft 120 can be coaxial with the axis of the inner shaft 110.

[0036] Further, when the first fixture 210 and the second fixture 220 clamp the inner shaft 110 and the outer shaft 120 of the ball spline shaft 100, if the axes of the inner shaft 110 and the outer shaft 120 are not coaxial, the outer shaft 120 will have a restoring force to restore the coaxial state with the inner shaft 110. Since the inner shaft 110 and the outer shaft 120 are respectively clamped by the first fixture 210 and the outer shaft jaw 221, the outer shaft 120 will generate a thrust on the outer shaft jaw 221 under the action of this restoring force. And the outer shaft jaw 221 is connected to the floating mechanism, and the floating mechanism has a degree of freedom in the direction perpendicular to the moving direction of the second fixture 220. Therefore, the outer shaft 120 has a thrust on the outer shaft jaw 221, making the outer shaft jaw 221 have a thrust on the floating mechanism. Furthermore, the floating mechanism will move, and then the outer shaft jaw 221 will move in the direction perpendicular to the moving direction of the second fixture 220, and then the axis of the outer shaft 120 can be corrected, so that the outer shaft 120 can be restored to the coaxial state with the inner shaft 110.

[0037] It can be understood that through the mutual cooperation of the first fixture 210, the second fixture 220 and the floating mechanism, after the first fixture 210 and the second fixture 220 clamp the inner shaft 110 and the outer shaft 120 respectively, the inner shaft 110 and the outer shaft 120 can be kept in a coaxial state, and then the drawing force test of the ball spline shaft 100 can be carried out, which can preferably improve the accuracy of the test.

[0038] In some embodiments, the drawing force test mechanism further includes a test device body 200. Among them, the first fixture 210 and the second fixture 220 are both arranged on the test device body 200, and the first fixture 210 and the second fixture 220 are arranged opposite to each other. Further, the tray 230 can also be directly arranged on the test device body 200, or can be arranged outside and extend into the space between the first fixture 210 and the second fixture 220.

[0039] Further, a driving device 240 is provided on the main body 200 of the testing device. The driving device 240 can be connected to at least one of the first fixture 210 and the second fixture 220. By means of the driving device 240, the first fixture 210 and / or the second fixture 220 can be driven to move, so as to realize the mutual approach or mutual separation between the first fixture 210 and the second fixture 220, and further, the pulling force test on the ball spline shaft 100 can be realized. Further, the driving device 240 can be a motor or a cylinder, etc., and no special limitation is made thereto.

[0040] In some embodiments, the second fixture 220 further includes a pneumatic gripper 223. The pneumatic gripper 223 can cooperate with the outer shaft gripper 221 for clamping operations. Specifically, when the second fixture 220 clamps the outer shaft 120, the outer shaft gripper 221 and the pneumatic gripper 223 can clamp the outer shaft 120 simultaneously, thereby improving the stability of the second fixture 220 for clamping the outer shaft 120. When the first fixture 210 and the second fixture 220 perform a pulling force test on the ball spline shaft 100, the second fixture 220 is not easily separated from the outer shaft 120, making the test more stable and accurate.

[0041] In some embodiments, the crossed roller guide 222 is used as a floating mechanism. In this embodiment, the crossed roller guide 222 has three support plates 222a. A ball guide rail 222b is arranged between two adjacent support plates 222a. Through the arrangement of the ball guide rail 222b, the relative sliding between two adjacent support plates 222a can be realized. Since the number of support plates 222a in this embodiment is three, a total of two groups of ball guide rails 222b are arranged, and the arrangement directions of the two groups of ball guide rails 222b are different, so that the crossed roller guide 222 has degrees of freedom in two directions.

[0042] Further, when the outer shaft gripper 221 receives the thrust of the outer shaft 120, the outer shaft gripper 221 will transmit the thrust to the crossed roller guide 222. Further, the three support plates 222a in the crossed roller guide 222 will move relatively, so that the axis of the outer shaft 120 can be adjusted in a direction perpendicular to the moving direction of the second fixture 220, realizing the correction of the axis of the outer shaft 120, and further enabling the inner shaft 110 and the outer shaft 120 to maintain a coaxial state.

[0043] In some embodiments, both the outer shaft jaw 221 and the air jaw 223 are provided on the side of the crossed roller guide 222 facing the first fixture 210. In this embodiment, the air jaw 223 is located between the outer shaft jaw 221 and the crossed roller guide 222. That is to say, the outer shaft jaw 221 is indirectly connected to the crossed roller guide 222 through the air jaw 223. It can be understood that the crossed roller guide 222 can achieve the position movement of the outer shaft jaw 221 and the air jaw 223, while the positions between the outer shaft jaw 221 and the air jaw 223 are relatively fixed.

[0044] In some embodiments, a through hole 222c is provided in the crossed roller guide 222, and the through hole 222c penetrates through the crossed roller guide 222. The second fixture 220 further includes a centering cylinder 224, and the centering cylinder 224 is provided on the side of the crossed roller guide 222 away from the first fixture 210.

[0045] Furthermore, when the output shaft of the centering cylinder 224 extends into the through hole 222c, due to the resistance of the output shaft of the centering cylinder 224, the support plate 222a in the crossed roller guide 222 can be limited, so that the adjacent support plates 222a cannot slide relative to each other. When the output shaft of the centering cylinder 224 moves out of the through hole 222c, the limitation on the support plate 222a in the crossed roller guide 222 can be released, so that the adjacent support plates 222a can slide relative to each other through the ball guide 222b.

[0046] It can be understood that when actually performing a pulling force test on the ball spline shaft 100, first, the output shaft of the centering cylinder 224 is extended into the through hole 222c to limit the crossed roller guide 222. The ball spline shaft 100 is placed on the tray 230, and the first fixture 210 and the second fixture 220 are driven to approach each other so that the first fixture 210 clamps the inner shaft 110 and the second fixture 220 clamps the outer shaft 120. When the inner shaft 110 and the outer shaft 120 are in a coaxial state, the first fixture 210 and the second fixture 220 are driven to move away from each other, thereby realizing the pulling force test on the ball spline shaft 100. When the inner shaft 110 and the outer shaft 120 are not coaxial, the output shaft of the centering cylinder 224 is removed from the through hole 222c to release the limit of the centering cylinder 224 on the crossed roller guide 222. Then, under the push of the outer shaft 120, the outer shaft jaw 221 and the air claw 223 move in a direction perpendicular to the moving direction of the second fixture 220 through the crossed roller guide 222, thereby realizing the automatic correction of the axis of the outer shaft 120 and keeping the inner shaft 110 and the outer shaft 120 in a coaxial state. Then, the output shaft of the centering cylinder 224 is extended into the through hole 222c again to limit the crossed roller guide 222 by the centering cylinder 224 to avoid the shaking of the outer shaft 120. Furthermore, the first fixture 210 and the second fixture 220 move away from each other to realize the pulling force test on the ball spline shaft 100.

[0047] In some embodiments, a tensile and compressive force sensor (not shown in the figure) is provided on the first fixture 210 and / or the second fixture 220. When the first fixture 210 and the second fixture 220 move away from each other to perform a pulling force test on the ball spline shaft 100, the pulling force applied to the ball spline shaft 100 can be conveniently and quickly obtained through the tensile and compressive force sensor.

[0048] In a second aspect, in combination with Figure 7 As shown, the present embodiment further provides a method for testing the pulling force of the ball spline shaft 100. This method is applied to the above-mentioned pulling force test mechanism of the ball spline shaft 100. Specifically, the method includes,

[0049] Step S100: Clamp the inner shaft 110 and the outer shaft 120 of the ball spline shaft 100 through the first fixture 210 and the second fixture 220 respectively;

[0050] Step S200: When the inner shaft 110 and the outer shaft 120 are coaxial, drive the first fixture 210 and the second fixture 220 to move away from each other to test the pulling force between the inner shaft 110 and the outer shaft 120; when the inner shaft 110 and the outer shaft 120 are not coaxial, adjust the axis of the outer shaft 120 through the floating mechanism on the second fixture 220.

[0051] In some embodiments, in step S200, the axis of the outer shaft 120 is adjusted by the floating mechanism on the second fixture 220. Specifically, the second fixture 220 is driven to move closer to the first fixture 210, so that the centering cylinder 224 releases the limit on the floating mechanism.

[0052] In some embodiments, in step S200, after the axis of the outer shaft 120 is adjusted by the floating mechanism on the second fixture 220, the second fixture 220 is driven to move away from the first fixture 210, so that the centering cylinder 224 limits the floating mechanism.

[0053] In summary, the above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the patent of the present invention.

Claims

1. The pull-out force testing mechanism of the ball spline shaft is characterized by: It comprises a tray for supporting a ball spline shaft, and a first clamp and a second clamp respectively arranged on both sides of the tray; The first clamp and the second clamp are used to clamp the inner shaft and the outer shaft of the ball spline shaft respectively, and the second clamp can move relative to the first clamp to achieve drawing of the ball spline shaft; The second clamp is provided with an outer shaft clamping jaw and a floating mechanism, and the second clamp clamps the outer shaft through the outer shaft clamping jaw; When the first clamp and the outer shaft clamp respectively clamp the inner shaft and the outer shaft, the outer shaft clamp can move in a direction perpendicular to the movement direction of the second clamp through the floating mechanism to keep the inner shaft and the outer shaft in a coaxial state.

2. The pull-out force testing mechanism according to claim 1, characterized in that: The first fixture and the second fixture are both arranged on the test device body; the test device body is also provided with a driving device connected to the first fixture and / or the second fixture to achieve relative movement of the first fixture and the second fixture.

3. The pull-out force testing mechanism according to claim 1, characterized in that: The second clamp also includes an air gripper that cooperates with the outer shaft gripper for clamping.

4. The pull-out force testing mechanism according to claim 3, characterized in that: The floating mechanism is a cross roller guide.

5. The pull-out force testing mechanism according to claim 4, characterized in that: The outer shaft clamp and the air clamp are both arranged on a side of the cross roller guide rail facing the first clamp.

6. The pull-out force testing mechanism according to claim 4, characterized in that: The second fixture further comprises a centering cylinder arranged on a side of the cross roller guide rail away from the first fixture; a through hole is arranged on the cross roller guide rail; When the output shaft of the centering cylinder extends into the through hole, the cross roller guide is limited in a direction perpendicular to the movement direction of the second clamp; when the output shaft of the centering cylinder moves out of the through hole, the cross roller guide can move in a direction perpendicular to the movement direction of the second clamp to adjust the axis of the outer shaft to remain coaxial with the axis of the inner shaft.

7. The pull-out force testing mechanism according to claim 1, characterized in that: The first clamp and / or the second clamp is provided with a tension and pressure sensor.

8. A method for testing the pull-out force of a ball spline shaft, characterized in that: Applicable to the pull-out force testing mechanism described in any one of claims 1 to 7, include, Clamp the inner shaft and the outer shaft of the ball spline shaft respectively by a first clamp and a second clamp; When the inner shaft and the outer shaft are not coaxial, the axis of the outer shaft is adjusted by the floating mechanism on the second fixture; when the inner shaft and the outer shaft are coaxial, the first fixture and the second fixture are driven away from each other to test the pulling force between the inner shaft and the outer shaft.

9. The pull-out force testing method according to claim 8, characterized in that: The axis of the outer shaft is adjusted by the floating mechanism on the second fixture, specifically including: The second clamp is driven to move close to the first clamp, so that the centering cylinder releases the limit on the floating mechanism.

10. The pull-out force testing method according to claim 9, characterized in that: After the second fixture adjusts the axis of the outer shaft through the floating mechanism, the second fixture is driven to move away from the first fixture, so that the centering cylinder limits the floating mechanism.

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