A pre-tightening buffer damper posture reset precision adjusting device and a process method thereof

Abstract

The application relates to a pre-tightening buffer damper posture reset precision adjusting device, which is characterized in that a cylindrical supporting part is fixedly installed on the upper surface of a supporting plate; a bearing bush is fixedly installed on the bottom surface of the supporting plate; a brush DC motor is installed on the bottom plate; the brush DC motor drives an axial push rod; the upper end of the axial push rod penetrates through the bearing bush and extends into the bottom of the supporting part; a bearing pressing plate is packaged on the bottom surface of the bearing bush. The rising or retraction of the push rod device is realized by changing the voltage of the axial push rod brush DC motor; the axial push rod moves up and down along the DC bearing installed in the bearing bush, and the stroke range of the axial push rod is completed; a recess-shaped positioning end with a pre-tightening buffer damper shaft bottom opening is arranged on the upper end surface of the axial push rod. The application also relates to a pre-tightening buffer damper posture reset precision adjusting process method, which optimizes and improves the adjusting process, improves the assembly precision, and improves the product quality.

Description

Technical Field

[0001] This invention belongs to the field of assembly and adjustment technology of pre-tightened buffer dampers for precision instruments, and in particular, it relates to a device and process method for adjusting the attitude reset accuracy of a pre-tightened buffer damper. Background Technology

[0002] Based on Stewart's design philosophy, the parallel buffer device features a simple and compact structure, capable of significantly unloading impact loads from any direction. Its main component, the preloaded damper, effectively achieves high static stiffness and low dynamic stiffness. Attitude reset accuracy refers to the accuracy achieved when the equipment is subjected to a large impact load. The preloaded damper in the parallel buffer base engages, stretching or compressing, causing equipment displacement. After the impact, the preloaded damper, under the action of elastic force, returns to its initial state, and the equipment returns to its initial technical condition. The factors affecting attitude reset accuracy are related to the assembly process of the preloaded damper. To ensure high attitude reset accuracy of the equipment relative to the buffer base, high requirements are placed on the assembly accuracy of the preloaded damper, necessitating optimization and improvement of its assembly and adjustment process. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a pre-tightened buffer damper attitude reset accuracy assembly and adjustment device, which optimizes and improves the assembly and adjustment process, improves assembly accuracy, and thus improves product quality.

[0004] The present invention also aims to provide a process for adjusting the attitude reset accuracy of a pre-tightened buffer damper.

[0005] The technical problem solved by this invention is achieved through the following technical solution: A device for adjusting the attitude reset accuracy of a preloaded damper includes a support member, a support plate, a column, and a base plate. The column is fixedly installed between the support plate and the base plate. A cylindrical support member is fixedly installed on the upper surface of the support plate. A bearing bushing is fixedly installed on the bottom surface of the support plate. A brushed DC motor is installed on the base plate. The brushed DC motor drives an axial push rod. The upper end of the axial push rod passes through the bearing bushing and extends to the bottom of the support member. A bearing pressure plate is sealed on the bottom surface of the bearing bushing. The voltage change of the brushed DC motor of the axial push rod realizes the raising or retracting of the push rod device, pushing the axial push rod to move up and down along the DC bearing installed in the bearing bushing, completing the stroke range of the axial push rod. A groove-shaped positioning end with an opening at the bottom of the preloaded damper spindle is formed on the upper end surface of the axial push rod.

[0006] A method for adjusting the attitude reset accuracy of a pre-tightened buffer damper includes the following steps: 1) Assembly of the spring preload core component: 1.1 Install the second axial sleeve along the upper end of the mandrel. It is a clearance fit, with flexible sliding and no jamming. Install the spring along the upper end of the mandrel so that the installed end of the spring fits against the outside of the upper end of the second axial sleeve. Then install the first axial sleeve along the upper end of the mandrel so that the installed end of the first axial sleeve fits against the inside of the upper end of the spring. 1.2 Place the assembly assembled in step 1.1 in the support of the assembly and adjustment device. Place the lower end of the mandrel on the positioning end of the axial push rod. Clamp the upper end face of the first axial sleeve on the upper shoulder inside the cavity of the support. Start the brushed DC motor of the axial push rod. The push rod device extends to push the axial push rod to move vertically along the axis, pushing the mandrel upward. The first axial sleeve is clamped on the inner wall at the upper end of the support, causing the spring to deform elastically, compressing the length of the spring, and the mandrel extends out through the through-hole of the first axial sleeve. 1.3 Screw a locking nut along the upper end of the mandrel into the stop of the mandrel. Screw in the second locking nut until its end face abuts against the end face of the first locking nut to achieve double-nut interlocking. Install the transition piece to protect the fine-thread on the right end of the mandrel during subsequent adjustments. After installation, a spring pre-tightening core assembly is formed. 1.4 Take out the spring pre-tightening core assembly from the assembly and adjustment device and wait for the next adjustment test. 2) Adjustment and test of the spring pre-tightening core assembly: 2.1 Use a press to conduct a pressure test on the assembled spring pre-tightening core assembly. Place the assembled spring pre-tightening core assembly on the support tooling. The support tooling supports on the lower end face of the second axial sleeve. The lower end of the mandrel is in the hollow of the support tooling. Use the control panel of the press to control the press body so that the press ram continuously compresses 4 mm starting from the initial position where the top of the mandrel is located. Measure the force-displacement curve. The inflection point of the pre-tightening force is near 1202.5 N, which is equivalent to the set value and meets the design requirements. 2.2 During the pressure test, an unsatisfactory curve may appear, and the change in force during compression is discontinuous. The reason is the jamming caused by improper assembly of the spring in the spring pre-tightening core assembly. When this phenomenon occurs, it is necessary to disassemble and assemble the components of the spring pre-tightening core assembly and then check and修整 the spring mating relationship until an ideal curve is obtained. 2.3 Re-assemble the修整 spring using the assembly process steps and conduct a pressure test. The pressure-displacement curve shown by the ideal curve is considered qualified. 3) Compensate for the length error of the spring pre-tightening core assembly: The spring preloading core component determines the preloading force of the preloading buffer damper. The spring is compressed by the locking nut to ensure the set initial preloading force. The limiting outer shell plays a limiting role. Assembly adjustment pads are added in the limiting outer shell for length error compensation. Axial play is not allowed, otherwise it will affect the attitude reset accuracy of the entire buffer device. By adjusting the adjustment pads, compensation can be made for the actual machining dimensional errors of the parts, effectively reducing the structural pose error caused by the length error of the rod component.

[0007] Moreover, it also includes step 4) the adjustment pad thickness adjustment step: According to the circumferential rotational flexibility of the limiting outer shell and the spring preloading core component, the thickness of the adjustment pad is finely adjusted. The limiting outer shell is fixed, and a purchased torque wrench is used to turn the transition piece to rotate the spring preloading core component. There will be a measured frictional force F2 between the outer end face of the guide sleeve and the contact surface (27) of the two end covers. Compared with the ideal frictional force F3, there are three change situations during the adjustment process. The measured thickness of the adjustment pad is C0, and the ideal thickness of the adjustment pad is C. That is, the relationship between F2 and F3 is: (1) When F2 < F3, C0 > C, the spring preloading core component and the limiting outer shell do not have effective contact, and the circumferential rotation of the limiting outer shell is too flexible. The thickness C of the adjustment pad needs to be moderately reduced by grinding. (2) When F2 > F3, C0 < C, the spring preloading core component is further squeezed by the limiting outer shell, the spring preloading force increases, the limiting outer shell cannot rotate, but the spring preloading core component is relatively easy to rotate. The rod component needs to be disassembled and adjusted. (3) When F2 and F3 are close, C0 = C, which is the ideal state of adjustment. At this time, the spring preloading core component is relatively difficult to rotate, and the limiting outer shell has a certain degree of rotational freedom.

[0008] The advantages and beneficial effects of the present invention are: 1. The attitude reset accuracy assembly and adjustment device and its process method of the preloading buffer damper of the present invention, aiming at the assembly difficulty of ensuring attitude accuracy, through analyzing the preloading and limiting structure, introducing the selection and adjustment process method of the buffer body spring into the assembly of the buffer damper; selecting the spring preloading core within the design range through pressure testing, combining the dimensional chain and force analysis of the parts, calculating the thickness compensation value of the assembly adjustment pad, and compensating the length error of the spring preloading core by adjusting the thickness of the adjustment gasket to improve the assembly accuracy. Brief Description of the Drawings

[0009] Figure 1 It is a schematic diagram of the preloading and limiting structure of the present invention; Figure 2 It is a schematic diagram of the structure of the spring preloading core pressing device of the present invention; Figure 3This is a half-sectional structural diagram of the spring pre-tightening core pressing device of the present invention; Figure 4 This is a schematic diagram of the spring preload core pressure testing structure of the present invention; Figure 5a This is a schematic diagram of the spring preload core force-displacement curve obtained by the present invention (a non-ideal curve); Figure 5b This is a schematic diagram of the spring preload core force-displacement curve obtained by the present invention (ideal curve); Figure 6 This is a schematic diagram of the pre-tightened buffer damper structure of the present invention; Figure 7 This is a schematic diagram of the forces acting on the pre-tightened buffer damper during the installation and adjustment process of the present invention.

[0010] Explanation of reference numerals in the attached figures 1-Spring preload core component, 2-Limiting housing, 3-First axial sleeve, 4-Second axial sleeve, 5-Mandrel, 6-Spring, 7-Locking nut, 8-Transition piece, 9-Support piece, 10-Support plate, 11-Column, 12-Base plate, 13-Bearing bushing, 14-Axial push rod, 15-Electric push rod, 16-Bearing pressure plate, 17-Brushed DC motor, 18-Linear bearing body, 19-Pressing rod, 20-Support fixture, 21-Control panel, 22-Pressing body, 23-Damper end cover, 24-Front end cover, 25-Outer cylinder, 26-Adjusting pad, 27-Contact surface. Detailed Implementation

[0011] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0012] A pre-tightened buffer damper attitude reset accuracy adjustment device, comprising a pre-tightened buffer damper and an adjustment device, has the following specific structure: The above-mentioned pre-tightened buffer damper, such as Figure 1 As shown, its structure includes a spring preload core assembly 1 and a limiting shell 1. The spring preload core assembly includes a spindle 5, a spring 6, a first axial sleeve 3, a second axial sleeve 4, a locking nut 7, and a transition piece 8. The second axial sleeve is inserted into the spindle and axially positioned with a retaining plate made at the bottom of the spindle. The spring is fitted on the second axial sleeve. The first axial sleeve is fitted on the upper part of the spring and the spindle. The upper end of the spindle has threads. The locking nut is installed on the upper part of the spindle. The spring is preloaded by the first axial sleeve. The transition piece is installed on the upper part of the locking nut to protect the fine threads at the upper end of the spindle.

[0013] The specific structure of the assembly and adjustment device, such as Figure 2As shown, the device includes a support member 9, a support plate 10, a column 11, and a base plate 12. The column is fixedly installed between the support plate and the base plate. A cylindrical support member is fixedly installed on the upper surface of the support plate. A bearing bushing 13 is fixedly installed on the bottom surface of the support plate. A brushed DC motor 17 is installed on the base plate. The brushed DC motor drives an electric push rod 14, which in turn drives an electric push rod 15. The upper end of the axial push rod passes through the bearing bushing and the linear bearing body 18 and extends into the bottom of the support member. A bearing pressure plate 16 is sealed on the bottom surface of the bearing bushing. The voltage change of the brushed DC motor of the axial push rod realizes the raising or lowering of the push rod device, pushing the axial push rod to move up and down along the DC bearing body 18 installed in the bearing bushing, thus completing the stroke range of the axial push rod.

[0014] A groove-shaped positioning end with an opening at the bottom of the preloaded buffer damper spindle is formed on the upper end face of the axial push rod.

[0015] The pre-tightened buffer damper attitude reset accuracy adjustment process of the present invention includes the following steps: 1) Assembly of the spring preload core component: 1.1 The second axial sleeve is installed along the upper end of the mandrel, which is a clearance fit, allowing for flexible sliding without jamming; the spring is installed along the upper end of the mandrel, so that the installed end of the spring is in contact with the outer upper end of the second axial sleeve; the first axial sleeve is then installed along the upper end of the mandrel, so that the installed end of the first axial sleeve is in contact with the inner upper end of the spring.

[0016] 1.2 Place the components assembled in step 1.1 into the support of the assembly and adjustment device. Place the lower end of the mandrel on the positioning end of the axial push rod. Secure the upper end face of the first axial sleeve to the upper shoulder of the inner cavity of the support. Start the brushed DC motor of the axial push rod. The push rod device extends and pushes the axial push rod to move vertically along the axial direction, pushing the mandrel to move upward. The first axial sleeve is secured to the upper inner wall of the support, causing the spring to deform elastically and compress its length. The mandrel extends out through the through hole of the first axial sleeve.

[0017] 1.3 Screw a locking nut into the stop of the mandrel along the upper end; screw the second locking nut into the end face of the first locking nut until they are close together to achieve double nut interlocking; install the transition piece to protect the fine thread on the right end of the mandrel during subsequent adjustments, and after installation, a spring preload core component is formed. 1.4 Remove the spring preload core component from the self-adjusting device and wait for the next adjustment and testing step. 2) Adjustment test of the core spring preload component: 2.1 Use a press to perform a pressure test on the assembled spring preload core component, such as... Figure 4As shown in the figure, a cylindrical hollow support tooling is designed. The assembled spring pre-tightening core component is placed on the support tooling. The support tooling supports on the lower end face of the second axial sleeve. The lower end of the mandrel is in the hollow part of the support tooling 20. The control panel 21 of the press is used to control the press main body 22, so that the press ram 19 continuously compresses 4 mm starting from the initial position where the top end of the mandrel is located. The measured force-displacement curve is shown in Figure 5. Its pre-tightening force inflection point is near 1202.5 N, which is equivalent to the set value and meets the design requirements.

[0018] 2.2 During the pressure test, an不理想 curve as shown in Figure 5 may appear. The change of force during compression is discontinuous. The reason is the jamming caused by improper assembly of the spring in the spring pre-tightening core component. When this phenomenon occurs, it is necessary to disassemble and assemble the spring pre-tightening core component and then check and修整 the spring fitting relationship until the ideal curve in Figure 5 is achieved.

[0019] 2.3 Re-assemble the修整 spring using the assembly process steps and conduct a pressure test. The pressure-displacement curve shown in the ideal curve in Figure 5 is considered qualified.

[0020] 3) Compensate for the length error of the spring pre-tightening core component: The spring pre-tightening core component determines the pre-tightening force of the pre-tightening buffer damper. The set initial pre-pressure is ensured by tightening the spring with a lock nut. The limit housing plays a limiting role and is the positioning reference of the pre-tightening buffer damper. An assembly adjustment pad is added in the limit housing. It is the closed-loop part of the limit housing dimension chain and the adjustment part to meet the force performance index, and is used for length error compensation. Axial end play is not allowed, otherwise it will affect the attitude reset accuracy of the entire buffer device.

[0021] Step 4) Fine-tune the thickness of the adjustment pad: As Figure 6 shown in the figure, a limit housing is arranged outside the spring pre-tightening core component. The limit housing is composed of a damper end cover 23, an outer cylinder 25, an adjustment pad 26 and a front end cover 24. The outer cylinder is sleeved outside the spring of the spring pre-tightening core component. The front end cover is sleeved on the transition part and then fixed to the outer cylinder. After the axial dimension of the mandrel is processed according to the drawing, when assembled, the accumulated dimension chains, the axial dimension error is greater than the dimension between the outer end faces of the two guide sleeves of the spring pre-tightening core component. The spring pre-tightening core component has a slight end play in the limit housing.

[0022] Fine-tune the thickness of the adjustment pad according to the circumferential rotational flexibility between the limit housing and the spring pre-tightening core component. Fix the limit housing and use the purchased torque wrench to turn the transition part to rotate the spring pre-tightening core component. There will be a measured frictional force F2 between the contact surface 27 between the outer end face of the guide sleeve and the two end covers. As Figure 7As shown, compared with the frictional force F3 in the ideal state (the frictional force generated by calculating the pre-tightening force set by the spring pre-tightening core component), there are three change situations during the adjustment process. The measured thickness of the adjustment pad is C0, and the ideal thickness of the adjustment pad is C. That is, the relationship between F2 and F3 is as follows: (1) When F2 < F3, C0 > C. The spring pre-tightening core component and the limit housing are not in effective contact, and the circumferential rotation of the limit housing is too flexible. It is necessary to appropriately reduce the thickness C of the adjustment pad by grinding.

[0023] (2) When F2 > F3, C0 < C. The spring pre-tightening core component is further squeezed by the limit housing, the spring pre-tightening force increases, the limit housing cannot rotate, but the spring pre-tightening core component is relatively easy to rotate. It is necessary to disassemble and adjust the rod component.

[0024] (3) When F2 is close to F3, C0 = C. This is the ideal state of adjustment. At this time, the spring pre-tightening core component is relatively difficult to rotate, and the limit housing has a certain degree of rotational freedom.

[0025] By adjusting the adjustment pad, it is possible to compensate for the actual machining dimension error of the parts, and effectively reduce the structural pose error caused by the length error of the rod component.

[0026] The length error compensation method proposed by the present invention has strong operability. The buffer device assembled according to this method has excellent attitude reset accuracy and is widely used in the assembly of pre-tightening parallel buffer devices with high attitude accuracy requirements.

[0027] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art can understand that various substitutions, changes, and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the content disclosed in the embodiments and drawings.

Claims

1. A method for adjusting the attitude reset accuracy of a pre-tightened buffer damper, characterized in that: The device for adjusting the attitude reset accuracy of the pre-tightened buffer damper includes a support member (9), a support plate (10), a column (11), and a base plate (12). The column (11) is fixedly installed between the support plate (10) and the base plate (12). A cylindrical support member (9) is fixedly installed on the upper surface of the support plate (10). A bearing bushing (13) is fixedly installed on the bottom surface of the support plate (10). A brushed DC motor (17) is installed on the base plate (12). The brushed DC motor (17) drives an axial push rod (14). 4) The upper end passes through the bearing bushing (13) and extends to the bottom of the support (9). The bearing pressure plate (16) is sealed on the bottom surface of the bearing bushing (13). The axial push rod (14) is raised or retracted by the change of voltage of the brushed DC motor (17). The axial push rod (14) is pushed to move up and down along the linear bearing body installed in the bearing bushing (13) to complete the stroke range of the axial push rod (14). A groove-shaped positioning end is made on the upper end face of the axial push rod (14) to cooperate with the bottom plate of the pre-tightened buffer damper spindle (5). The process includes the following steps: Step 1) Assembly of the spring preload core assembly (1): 1.1 Insert the second axial sleeve (4) along the upper end of the mandrel (5). It is a clearance fit, which allows for flexible sliding without jamming. Insert the spring (6) along the upper end of the mandrel (5) so that the insertion end of the spring (6) is in contact with the outer upper end of the second axial sleeve (4). Then insert the first axial sleeve (3) along the upper end of the mandrel (5) so that the insertion end of the first axial sleeve (3) is in contact with the inner upper end of the spring (6). 1.2 Place the components assembled in step 1.1 into the support (9) of the assembly and adjustment device. Place the lower end of the spindle (5) on the positioning end of the axial push rod (14). Secure the upper end face of the first axial sleeve (3) to the upper shoulder of the inner cavity of the support (9). Start the brushed DC motor (17) of the axial push rod (14). The push rod device extends and pushes the axial push rod (14) to move vertically along the axial direction, pushing the spindle (5) to move upward. The first axial sleeve (3) is secured to the upper inner wall of the support (9), causing the spring (6) to deform elastically. The length of the spring (6) is compressed, and the spindle (5) extends out through the through hole of the first axial sleeve (3). 1.3 Screw a locking nut (7) into the stop of the mandrel (5) along the upper end of the mandrel (5); screw a second locking nut into the end face of the first locking nut (7) until they are close together, so as to achieve double nut interlocking; install the transition piece (8) to protect the fine thread on the right end of the mandrel (5) in subsequent adjustments, and after installation, a spring preload core assembly (1) is formed. 1.4 Remove the spring preload core assembly (1) from the self-adjusting device and wait for the next adjustment test; Step 2) Adjustment test of the spring preload core assembly (1): 2.1 Use a press to conduct a pressure test on the assembled spring pre-tightening core component (1). Place the assembled spring pre-tightening core component (1) on the support tooling (20). The support tooling (20) supports on the lower end face of the second axial sleeve (4). The lower end of the mandrel (5) is in the hollow of the support tooling (20). Use the control panel (21) of the press to control the press main body (22), so that the press ram (19) continuously compresses 4 mm starting from the initial position where the top end of the mandrel (5) is located. The measured force-displacement curve has a pre-tightening force inflection point near 1202.5 N, which is equivalent to the set value and meets the design requirements. 2.2 During the pressure test, an不理想 curve may occur, and the change of force during compression is discontinuous. The reason is the jamming caused by improper assembly of the spring (6) in the spring pre-tightening core component (1). When this phenomenon occurs, it is necessary to disassemble and assemble the spring pre-tightening core component (1) and then check and修整 the mating relationship of the spring (6) until an理想 curve is obtained. 2.3 Re-assemble the修整 spring (6) using the assembly process steps and conduct a pressure test. The pressure-displacement curve shown by the理想 curve is considered qualified. Step 3) Compensate for the length error of the spring pre-tightening core component (1): The spring pre-tightening core component (1) determines the pre-tightening force of the pre-tightening buffer damper. The spring (6) is compressed by two lock nuts to ensure the set initial pre-pressure. An outer limiting shell (2) is provided outside the spring pre-tightening core component (1), and the outer limiting shell (2) plays a limiting role. Assembly adjustment pads are added in the outer limiting shell (2) for length error compensation, and axial movement is not allowed. Through the adjustment of the adjustment pads, compensate for the actual machining dimension error of the parts and reduce the structural pose error caused by the length error of the spring pre-tightening core component (1).

2. According to the pre-tightening buffer damper attitude reset accuracy assembly and adjustment process method described in claim 1, it is characterized in that: It further includes step 4) Adjustment pad thickness adjustment step: Fine-tune the thickness of the adjustment pad according to the circumferential rotation flexibility of the outer limiting shell (2) and the spring pre-tightening core component (1). Fix the outer limiting shell (2), and use a torque wrench to turn the transition piece to rotate the spring pre-tightening core component (1). There will be a measured frictional force F2 between the outer end face of the guide sleeve and the contact surface (27) of the two end covers. Compared with the ideal frictional force F3, there are three change situations during the adjustment process. The measured thickness of the adjustment pad is C0, and the ideal thickness of the adjustment pad is C. That is, the relationship between F2 and F3 is: (1) When F2 < F3, C0 > C, the spring pre-tightening core component (1) and the outer limiting shell (2) do not have effective contact, and the circumferential rotation of the outer limiting shell (2) is too flexible. It is necessary to use the grinding method to moderately reduce the thickness C0 of the adjustment pad. (2) When F2 > F3, C0 < C, the spring pre-tightening core component (1) is further squeezed by the outer limiting shell (2), the spring pre-tightening force increases, the outer limiting shell (2) cannot rotate, but the spring pre-tightening core component (1) is relatively easy to rotate. It is necessary to disassemble and assemble and adjust the spring pre-tightening core component (1). (3) When F2 and F3 are close, C0=C, which is the ideal state of adjustment. At this time, the spring preload core component (1) is difficult to rotate, and the limiting shell (2) has a certain degree of rotational freedom.

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