A plunger and sliding shoe inner and outer spherical surface roundness detection device and method

Abstract

This invention relates to a device and method for detecting the roundness of the inner and outer spherical surfaces of a plunger and a slipper. The slipper detection assembly contains a first spring, and its upper end is equipped with a slipper test head assembly, which includes a fixed slipper test head and a floating slipper test head. The fixed slipper test head is fixed to the upper end of the slipper detection assembly, and the lower end of the floating slipper test head is connected to the first spring, while its upper end is inserted into the fixed slipper test head. The plunger detection assembly contains a second spring, and its upper end is equipped with a ball head test head assembly, which includes a fixed ball head test head and a floating ball head test head. The fixed ball head test head is fixed to the upper end of the plunger detection assembly, and the lower end of the floating ball head test head is connected to the second spring, while its upper end is inserted into the fixed ball head test head. Force sensors are located at the bottom of both the first and second springs. This invention can quickly detect and obtain the outer spherical radius of the plunger ball head and the inner spherical radius of the slipper.

Description

Technical Field

[0001] This invention relates to the field of hydraulic component testing technology, specifically to a device and method for testing the roundness of the inner and outer spherical surfaces of a plunger and a slipper. Background Technology

[0002] Various pumps and hydraulic motors are important power and actuators in hydraulic systems, and are widely used in industrial machinery. The piston slipper assembly is an important component of the pump or motor. When the pump or motor rotates at high speed, the piston slipper assembly is tightly attached to the swashplate and moves with the cylinder. During the pump or motor's operating cycle, forces such as centrifugal force, slipper pair friction, and contact force between the piston and cylinder bore are generated, and their magnitude and direction change at any time. These forces affect the reliability of the core components inside the pump or motor.

[0003] like Figures 1-3 As shown, the plunger slipper assembly includes a slipper and a plunger. The plunger's ball head is wrapped into the slipper using a pressing and ball-wrapping process, allowing the ball head to rotate flexibly within a certain angle range to adapt to the movement of the swashplate and cylinder block. However, in actual production, due to issues with the roundness of the inner and outer spherical surfaces of the plunger slipper, the pressed and wrapped plunger slipper assembly often experiences problems such as inflexible rotation, jamming, ball head wear, and breakage. Therefore, the roundness inspection of the inner and outer spherical surfaces of the plunger and slipper is crucial, as it affects the assembly and use of subsequent products. However, in existing technologies, the roundness inspection of the inner and outer spherical surfaces of the plunger and slipper is mainly done manually, which is not only inefficient but also prone to errors. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for detecting the roundness of the inner and outer spherical surfaces of a plunger and a slipper, which can quickly detect the outer spherical radius of the plunger head and the inner spherical radius of the slipper, thereby improving detection efficiency and accuracy.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A device for detecting the roundness of the inner and outer spherical surfaces of a plunger and a slipper includes a slipper detection assembly and a plunger detection assembly. The slipper detection assembly contains a first spring. The upper end of the slipper detection assembly has a slipper test head assembly, which includes a fixed slipper test head and a floating slipper test head. The fixed slipper test head is sleeve-shaped and fixed to the upper end of the slipper detection assembly. The lower end of the floating slipper test head is connected to the first spring, and its upper end is inserted into the fixed slipper test head. During detection, the upper ends of both the fixed and floating slipper test heads abut against the inner spherical surface of the slipper's underside. The plunger detection assembly has a second spring inside. The upper end of the plunger detection assembly has a ball head test head assembly, which includes a fixed ball head test head and a floating ball head test head. The fixed ball head test head is sleeve-shaped and fixed to the upper end of the plunger detection assembly. The lower end of the floating ball head test head is connected to the second spring, and the upper end is inserted into the fixed ball head test head. During detection, the upper ends of both the fixed ball head test head and the floating ball head test head abut against the outer spherical surface of the plunger ball head at the lower end of the plunger. Force sensors are provided at the bottom of the first spring and the bottom of the second spring, and the force sensors are connected to the control system.

[0007] The slipper detection assembly is provided with a first mounting base, which is vertically disposed on the base. The first mounting base is provided with a first receiving cavity, and the first spring and the slipper test head assembly are both disposed in the first receiving cavity. The slipper fixed test head in the slipper test head assembly is fixed at the upper opening of the first receiving cavity, and the upper end of the slipper fixed test head is higher than the upper surface of the first mounting base. When the first spring is in a naturally extended state, the upper end of the slipper floating test head is higher than the upper end of the slipper fixed test head.

[0008] The plunger detection assembly is provided with a second mounting base, which is vertically disposed on the base. The second mounting base is provided with a second receiving cavity, and the second spring and the ball head test head assembly are both disposed in the second receiving cavity. The ball head fixed test head in the ball head test head assembly is fixed at the upper opening of the second receiving cavity, and the inner diameter of the ball head fixed test head is smaller than the diameter of the plunger ball head. When the second spring is in a naturally extended state, the upper end of the ball head floating test head is flush with the upper end of the ball head fixed test head.

[0009] Both the slipper detection component and the plunger detection component are mounted on a base, and the base is equipped with a display screen that is connected to the control system.

[0010] A method for detecting the roundness of the inner and outer spherical surfaces of the plunger and slipper, according to the aforementioned plunger and slipper, includes the following steps:

[0011] Step 1: Determine the first rated spring constant s1 of the first spring and the second rated spring constant s2 of the second spring;

[0012] Step 2: Place the slipper on the slipper detection assembly and the plunger on the plunger detection assembly. Obtain the spring force Fa of the first spring and the spring force Fb of the second spring through the force sensor. Obtain the compression Ha of the first spring according to Hooke's law and the first calibration elastic coefficient s1 obtained in Step 1. Obtain the compression Hb of the second spring according to Hooke's law and the second calibration elastic coefficient s2 obtained in Step 1.

[0013] Step 3: Calculate the measured value of the inner spherical radius Ra on the lower side of the slipper and the measured value of the outer spherical radius Rb of the plunger head according to the following formula (3):

[0014]

[0015]

[0016] Step 4: Repeat steps 2 and 3 to obtain multiple Ra measurements and multiple Rb measurements. Then, take the maximum and minimum values ​​of the Ra measurements, divide them by 2, and average them to obtain the Ra value. Similarly, take the maximum and minimum values ​​of the Rb measurements, divide them by 2, and average them to obtain the Rb value.

[0017] Step 5: Compare the Ra and Rb values ​​obtained in Step 4 and determine the matching degree between the outer spherical surface of the plunger ball head and the inner spherical surface of the slipper.

[0018] In step one, multiple first ball gauge templates with radius Ra and multiple second ball gauge templates with radius Rb are manufactured. The first ball gauge templates are placed sequentially on the slipper test head assembly to obtain the detection spring force Fa of multiple first springs, and the second ball gauge templates are placed sequentially on the ball head test head assembly to obtain the detection spring force Fb of multiple second springs. Since the radii of the first and second ball gauge templates are known, the compression Ha of multiple first springs and the compression Hb of multiple second springs are calculated according to the following formula (3):

[0019]

[0020]

[0021] Then, according to Hooke's Law, the elastic coefficients s1' of the first springs and s2' of the second springs are obtained. The average value of each s1' is then calculated to obtain the first calibrated elastic coefficient s1, and the average value of each s2' is calculated to obtain the second calibrated elastic coefficient s2.

[0022] The advantages and positive effects of this invention are as follows:

[0023] 1. This invention utilizes Hooke's Law and the geometric relationships of related components to quickly calculate the outer spherical radius of the plunger ball head and the inner spherical radius of the slipper by detecting the spring force values ​​in the detection components of each component, thus greatly improving detection efficiency.

[0024] 2. In the testing process of this invention, the average elastic coefficient of the spring is first calibrated using a customized ball gauge template, and multiple radius measurements are obtained during testing. Finally, the maximum and minimum values ​​are averaged to obtain the final radius measurement value, so as to ensure the measurement accuracy to the greatest extent. After actual verification, the measurement accuracy of this invention is ±0.002mm. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention.

[0026] Figure 2 for Figure 1 Enlarged diagram of point A in the diagram.

[0027] Figure 3 for Figure 1 Enlarged diagram at point B in the diagram.

[0028] Figure 4 This is a schematic diagram of the workflow of the present invention.

[0029] Among them, 1 is the base, 2 is the slipper detection assembly, 201 is the first mounting base, 202 is the first spring, 203 is the slipper test head assembly, 2031 is the slipper fixed test head, 2032 is the slipper floating test head, 3 is the plunger detection assembly, 301 is the second mounting base, 302 is the second spring, 303 is the ball head test head assembly, 3031 is the ball head fixed test head, 3032 is the ball head floating test head, 4 is the slipper, 5 is the plunger, 501 is the plunger ball head, and 6 is the display screen. Detailed Implementation

[0030] The invention will now be described in further detail with reference to the accompanying drawings.

[0031] like Figures 1-4As shown, the present invention includes a base 1 and a slipper detection assembly 2 and a plunger detection assembly 3 disposed on the base 1. The slipper detection assembly 2 has a first spring 202 inside, and a slipper test head assembly 203 is provided at the upper end of the slipper detection assembly 2. The slipper test head assembly 203 includes a fixed slipper test head 2031 and a floating slipper test head 2032. The fixed slipper test head 2031 is sleeve-shaped and fixed to the upper end of the slipper detection assembly 2. The lower end of the floating slipper test head 2032 is connected to the first spring 202, and the upper end is inserted into the fixed slipper test head 2031. During detection, the fixed slipper test head 2031 and the floating slipper test head 2032... The upper ends of the plunger 32 abut against the inner spherical surface of the lower side of the slipper 4. A second spring 302 is provided inside the plunger detection assembly 3. A ball head test head assembly 303 is provided at the upper end of the plunger detection assembly 3, and the ball head test head assembly 303 includes a fixed ball head test head 3031 and a floating ball head test head 3032. The fixed ball head test head 3031 is sleeve-shaped and fixed to the upper end of the plunger detection assembly 3. The lower end of the floating ball head test head 3032 is connected to the second spring 302, and the upper end is inserted into the fixed ball head test head 3031. During detection, the upper ends of both the fixed ball head test head 3031 and the floating ball head test head 3032 abut against the outer spherical surface of the plunger ball head 501 at the lower end of the plunger 5. Force sensors are provided at the bottom of both the first spring 202 and the second spring 302, and these force sensors are connected to the control system of the present invention.

[0032] like Figure 1 As shown, the slipper detection assembly 2 is provided with a first mounting base 201, and the first mounting base 201 is vertically disposed on the base 1. The first mounting base 201 is provided with a first receiving cavity, and the first spring 202 and the slipper test head assembly 203 are both disposed in the first receiving cavity. The slipper fixing test head 2031 in the slipper test head assembly 203 is fixed at the upper opening of the first receiving cavity, and as shown... Figures 1-2 As shown, the height of the upper end of the fixed test head 2031 is higher than the upper surface of the first mounting base 201. When the first spring 202 is in a naturally extended state, the upper end of the floating test head 2032 is higher than the upper end of the fixed test head 2031, so that the inner spherical surface of the lower side of the slipper 4 can be fastened onto the slipper test head assembly 203 and abut against the floating test head 2032. The upper surface of the first mounting base 201 limits the downward displacement of the slipper 4.

[0033] like Figure 1As shown, the plunger detection assembly 3 is provided with a second mounting base 301, and the second mounting base 301 is vertically disposed on the base 1. The second mounting base 301 is provided with a second receiving cavity, and the second spring 302 and the ball head test head assembly 303 are both disposed in the second receiving cavity. The ball head fixing test head 3031 in the ball head test head assembly 303 is fixed at the upper opening of the second receiving cavity, and as shown... Figure 1 and Figure 3 As shown, the inner diameter of the ball head fixed test head 3031 is smaller than the diameter of the plunger ball head 501. When the second spring 302 is in its natural extended state, the upper end of the ball head floating test head 3032 is flush with the upper end of the ball head fixed test head 3031, so that the outer spherical surface of the plunger ball head 501 abuts against the ball head floating test head 3032 and compresses it into the ball head fixed test head 3031. The upper end of the ball head fixed test head 3031 limits the downward displacement of the plunger ball head 501.

[0034] like Figure 1 As shown, the base 1 is equipped with a display screen 6 which is connected to the control system. Figure 4 As shown, the results of the calculation and analysis by the control system of the present invention can be displayed on the display screen 6 in real time.

[0035] In this embodiment, the base 1 is made of marble, and each corner of its bottom is provided with rubber shock-absorbing pads to buffer external vibrations of the instrument and improve the instrument's testing accuracy.

[0036] The working principle of this invention is as follows:

[0037] like Figure 2 and Figure 3 As shown, the design purpose of this invention is to achieve rapid measurement of the inner spherical radius Ra of the lower side of the slipper 4 and the outer spherical radius Rb of the plunger ball head 501, thereby determining the dimensional conditions of the inner spherical surface of the slipper 4 and the outer spherical surface of the plunger ball head 501, and reducing the failure rate after assembly.

[0038] like Figure 2 and Figure 3 As shown, the measurement principle of this invention is based on the fact that the fixed test head has a fixed chord length L1 after contacting the spherical surface, and the floating test head has a fixed chord length L2 after contacting the spherical surface. The compression of the floating test head with different diameters is different. Since the spring force F and the spring compression (bow height) H are linearly related, the compression value H (bow height) is obtained by accurately detecting the spring force according to Hooke's Law, and then the required R value is indirectly calculated according to the geometric relationship. Hooke's Law is a well-known technology in this field, and its calculation is shown in the following formula (1):

[0039] F×s=H (1);

[0040] In equation (1) above, s is the elastic coefficient.

[0041] And such Figure 2 and Figure 3 As shown, the geometric relationship between L1, L2, H and the sphere R to be measured is shown in equation (2):

[0042]

[0043] In this embodiment, L1 is 5.23mm, L2 is 4.81mm, and the initial value of R is 5.45mm, which increases in increments of 0.0005mm each time. The change range of H can be obtained by calculating using the above formula (2). For every 0.0005mm change in R, that is, a 0.001mm change in diameter, the change range of H is 0.002478mm to 0.002871mm, which is more than twice the diameter change range of 0.001mm. Therefore, by detecting H, the value of R can be reflected more accurately.

[0044] like Figure 2 and Figure 3 As shown, assuming the fixed chord length of the fixed test head 2031 is L1a, the fixed chord length of the floating test head 2032 is L2a, the fixed chord length of the ball head fixed test head 3031 is L1b, the fixed chord length of the floating test head 3032 is L2b, s1 is the elastic coefficient of the first spring 202, and s2 is the elastic coefficient of the second spring 302.

[0045] The detection method of the present invention includes the following steps:

[0046] Step 1: Determine the first rated elastic coefficient s1 of the first spring 202 and the second rated elastic coefficient s2 of the second spring 302, specifically as follows:

[0047] Multiple first ball gauge templates with radius Ra and multiple second ball gauge templates with radius Rb are manufactured. The first ball gauge templates are placed sequentially on the slipper test head assembly 203 to obtain the detection spring force Fa of multiple first springs 202. The second ball gauge templates are placed sequentially on the ball head test head assembly 303 to obtain the detection spring force Fb of multiple second springs 302. Since the radii of the first ball gauge templates and the radii of the second ball gauge templates are known, the compression amount Ha of multiple first springs 202 and the compression amount Hb of multiple second springs 202 are obtained according to the following formula (3). Then, the elastic coefficients s1' of multiple first springs 202 and the elastic coefficients s2' of multiple second springs 302 are obtained according to Hooke's Law in the above formula (1). Then, the average value of each s1' is calculated to obtain the first calibration elastic coefficient s1, and the average value of each s2' is calculated to obtain the second calibration elastic coefficient s2.

[0048] Step 2: Place the slipper 4 on the slipper detection assembly 2 and the plunger 5 on the plunger detection assembly 3. Obtain the spring force Fa of the first spring 202 and the spring force Fb of the second spring 302 through the force sensor. Calculate the compression Ha of the first spring 202 according to Hooke's Law (1) and the first calibration elastic coefficient s1 obtained in Step 1. Calculate the compression Hb of the second spring 302 according to Hooke's Law (1) and the second calibration elastic coefficient s2 obtained in Step 1.

[0049] Step 3: Calculate the measured value of the inner spherical radius Ra on the lower side of the slipper 4 and the measured value of the outer spherical radius Rb of the plunger ball head 501 according to the following formula (3):

[0050]

[0051]

[0052] The Ra and Rb data are displayed directly on the display screen 6.

[0053] Step 4: Repeat steps 2 and 3 to obtain multiple Ra and multiple Rb measurements. Then, take the maximum and minimum values ​​of the Ra measurements, divide them by 2, and average them to obtain the Ra value. Similarly, take the maximum and minimum values ​​of the Rb measurements, divide them by 2, and average them to obtain the Rb value.

[0054] Step 5: Compare the Ra and Rb values ​​obtained in Step 4 and determine the matching degree between the outer spherical surface of the plunger ball head 501 and the inner spherical surface of the slipper 4.

Claims

1. A device for detecting the roundness of the inner and outer spherical surfaces of a plunger and a slipper, characterized in that: The system includes a slipper detection assembly (2) and a plunger detection assembly (3). The slipper detection assembly (2) has a first spring (202) inside. The upper end of the slipper detection assembly (2) has a slipper test head assembly (203). The slipper test head assembly (203) includes a slipper fixed test head (2031) and a slipper floating test head (2032). The slipper fixed test head (2031) is sleeve-shaped and fixed to the upper end of the slipper detection assembly (2). The lower end of the slipper floating test head (2032) is connected to the first spring (202), and the upper end is inserted into the slipper fixed test head (2031). During testing, the upper ends of both the slipper fixed test head (2031) and the slipper floating test head (2032) abut against the inner spherical surface of the lower side of the slipper (4). The plunger detection assembly (3) has a first spring (202) inside. Two springs (302), the upper end of the plunger detection assembly (3) is provided with a ball head test head assembly (303), and the ball head test head assembly (303) includes a ball head fixed test head (3031) and a ball head floating test head (3032). The ball head fixed test head (3031) is sleeve-shaped and fixed to the upper end of the plunger detection assembly (3). The lower end of the ball head floating test head (3032) is connected to the second spring (302), and the upper end is inserted into the ball head fixed test head (3031). During detection, the upper ends of the ball head fixed test head (3031) and the upper ends of the ball head floating test head (3032) abut against the outer spherical surface of the plunger ball head (501) at the lower end of the plunger (5). The bottom of the first spring (202) and the bottom of the second spring (302) are both provided with force sensors, and the force sensors are connected to the control system. The slipper detection assembly (2) is provided with a first mounting base (201), and a first accommodating cavity is provided in the first mounting base (201). The first spring (202) and the slipper test head assembly (203) are both located in the first accommodating cavity. The slipper fixed test head (2031) in the slipper test head assembly (203) is fixed at the upper opening of the first accommodating cavity. The upper height of the slipper fixed test head (2031) is higher than the upper surface of the first mounting base (201). When the first spring (202) is in a naturally extended state, the upper end of the slipper floating test head (2032) is higher than the upper end of the slipper fixed test head (2031). The plunger detection assembly (3) is provided with a second mounting base (301), and the second mounting base (301) is provided with a second accommodating cavity. The second spring (302) and the ball head test head assembly (303) are both located in the second accommodating cavity. The ball head fixed test head (3031) in the ball head test head assembly (303) is fixed at the upper opening of the second accommodating cavity. The inner diameter of the ball head fixed test head (3031) is smaller than the diameter of the plunger ball head (501). When the second spring (302) is in a naturally extended state, the upper end of the ball head floating test head (3032) is flush with the upper end of the ball head fixed test head (3031).

2. The plunger and slipper inner and outer spherical roundness detection device according to claim 1, characterized in that: The slipper detection component (2) and the plunger detection component (3) are both mounted on a base (1), and the base (1) is equipped with a display screen (6) connected to the control system.

3. A method for detecting the roundness of the inner and outer spherical surfaces of the plunger and slipper according to claim 1, characterized in that: Includes the following steps: Step 1: Determine the first rated elastic coefficient s1 of the first spring (202) and the second rated elastic coefficient s2 of the second spring (302); Step 2: Place the slipper (4) on the slipper detection assembly (2) and the plunger (5) on the plunger detection assembly (3). Obtain the spring force Fa of the first spring (202) and the spring force Fb of the second spring (302) through the force sensor. Obtain the compression amount Ha of the first spring (202) according to Hooke's law and the first calibration elastic coefficient s1 obtained in Step 1. Obtain the compression amount Hb of the second spring (302) according to Hooke's law and the second calibration elastic coefficient s2 obtained in Step 1. Step 3: Calculate the inner spherical radius Ra of the lower side of the slipper (4) and the outer spherical radius Rb of the plunger ball head (501) according to the following formula (3): ； （3）； In the above formula (3), the fixed chord length of the fixed test head (2031) is L1a, the fixed chord length of the floating test head (2032) is L2a, the fixed chord length of the fixed test head (3031) is L1b, and the fixed chord length of the floating test head (3032) is L2b. Step 4: Repeat steps 2 and 3 to obtain multiple Ra measurements and multiple Rb measurements. Then, take the maximum and minimum values ​​of the Ra measurements, divide them by 2, and average them to obtain the Ra value. Similarly, take the maximum and minimum values ​​of the Rb measurements, divide them by 2, and average them to obtain the Rb value. Step 5: Compare the Ra and Rb values ​​obtained in Step 4 and determine the matching degree between the outer spherical surface of the plunger ball head (501) and the inner spherical surface of the slipper (4).

4. The method for detecting the roundness of the inner and outer spherical surfaces of the plunger and slipper according to claim 3, characterized in that: In step one, multiple first ball gauge templates with radius Ra and multiple second ball gauge templates with radius Rb are manufactured. The first ball gauge templates are placed sequentially on the slipper test head assembly (203) to obtain the detection spring force Fa of multiple first springs (202). The second ball gauge templates are placed sequentially on the ball head test head assembly (303) to obtain the detection spring force Fb of multiple second springs (302). Since the radii of the first and second ball gauge templates are known, the compression Ha of the multiple first springs (202) and the compression Hb of the multiple second springs (302) are calculated according to the following formula (3): ； （3）； Then, according to Hooke's Law, the elastic coefficients s1' of multiple first springs (202) and s2' of multiple second springs (302) are obtained. Then, the average value of each s1' is calculated to obtain the first calibrated elastic coefficient s1, and the average value of each s2' is calculated to obtain the second calibrated elastic coefficient s2.

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