A feed mechanism for a grinding machine and a method of adjusting the same

Abstract

The application discloses a feeding mechanism for a grinding machine and an adjusting method thereof, and belongs to the technical field of machine tool components. The feeding mechanism comprises a drag plate provided with a machining tool, a ball screw pair arranged in the drag plate, the ball screw pair comprising a screw rod arranged between two bearing seats and a nut body arranged on the screw rod, a supporting seat arranged in the drag plate, a connecting member arranged in the supporting seat and used for connecting the drag plate and the nut body, the connecting member comprising a positioning portion arranged in the supporting seat and a sleeving portion sleeved with the nut body, an installation hole arranged in the supporting seat, the positioning portion arranged in the installation hole, a supporting member arranged in the installation hole and connected with the positioning portion, and a vibration elimination member arranged on the sleeving portion opposite to the nut body and used for eliminating transverse vibration of the ball screw pair. The application solves the problems of gravity sagging caused by the self weight of the screw rod and swinging caused by the eccentricity of the central holes of the two bearing seats during the rotation of the screw rod, and ensures the stable operation and reliable precision of the screw rod.

Description

Technical Field

[0001] This invention belongs to the field of machine tool component technology, and particularly relates to a feed mechanism for a grinding machine and its adjustment method. Background Technology

[0002] When grinding a workpiece, a grinding machine needs to move back and forth for tool feed, typically using a servo motor to drive a lead screw in reciprocating motion. For medium to large machine tools, when the lead screw travel is long or the lead screw is heavy, the middle position of the lead screw may sag due to its own weight. Alternatively, if the center holes of the bearing seats at both ends of the lead screw are not concentric, it affects the horizontal straightness accuracy of the lead screw. During the rotation of the lead screw, "peaks" and "valleys" are formed along the center line, causing the moving parts to jump and vibrate laterally. This, in turn, causes vibration in the machining tool during tool feed, resulting in noticeable vibration marks on the surface of the ground workpiece, leading to unacceptable surface roughness and affecting the workpiece accuracy during grinding. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a feed mechanism for a grinding machine and its adjustment method, which solves the problems of gravity sagging caused by the weight of the lead screw and the oscillation caused by the misalignment of the center holes of the two bearing seats when the lead screw rotates, ensuring that the lead screw runs smoothly and with reliable accuracy.

[0004] The present invention is implemented as follows: On one hand, the present invention provides a feed mechanism for a grinding machine, including a slide on which a machining tool is provided, a ball screw pair for driving the slide to move on a machine bed is provided inside the slide, the ball screw pair includes a lead screw disposed between two bearing seats and a nut body disposed on the lead screw, a support seat is provided inside the slide, and a connecting member for connecting the slide and the nut body is provided inside the support seat, the connecting member includes a positioning part disposed inside the support seat and a fitting part sleeved outside the nut body;

[0005] The support base is provided with a mounting hole, the opening direction of the mounting hole is perpendicular to the moving direction of the nut body, the positioning part is provided in the mounting hole, and a support component connected to the positioning part to prevent the positioning part from sinking is provided in the mounting hole.

[0006] A vibration damping component is provided on the sleeve part relative to the nut body to eliminate the lateral vibration of the ball screw pair.

[0007] Furthermore, the vibration damping component includes an adjusting nut sleeved on the lead screw, the connecting section of the adjusting nut extending into the sleeve portion, and an elastic element and an adjusting pad being sequentially arranged between the pre-tightening end face of the adjusting nut and the force-bearing end face of the sleeve portion.

[0008] Furthermore, a sleeve is provided between the flange end of the nut body and the lead screw, and the sleeve is connected to the nut body by a flush-cut screw.

[0009] Furthermore, the elastic element is a disc spring.

[0010] Furthermore, the mounting hole includes a large-diameter section and a small-diameter section that are connected. The small-diameter section is close to the nut body. The large-diameter section and the small-diameter section form a support stepped surface. The support member is disposed in the large-diameter section and supported on the support stepped surface.

[0011] Furthermore, the length of the support member is greater than the diameter of the smaller diameter segment.

[0012] Furthermore, the supporting member is a supporting washer, and the supporting washer is connected to the positioning part by an adjusting screw.

[0013] Furthermore, the sleeve part is coaxially arranged with the nut body.

[0014] Another aspect of the present invention provides a method for adjusting the feed mechanism of a grinding machine, comprising the following steps:

[0015] S1. The feed mechanism undergoes static adjustment during assembly:

[0016] S101. Fix the dial indicator base on the bed guide rail surface, place the indicator head on the upper busbar position of the lead screw, adjust the rear nut seat, and measure and control the accuracy of the upper busbar throughout its entire stroke.

[0017] S102. After the upper busbar measurement is completed, place the dial indicator head on the side busbar of the lead screw, adjust the rear nut seat, and measure and control the accuracy of the side busbar throughout its entire length.

[0018] S103. After the upper busbar and side busbar are adjusted, tighten the screws of the nut seat and bearing seat, and then measure the accuracy of the upper busbar and side busbar to check the accuracy and prevent the accuracy from changing after tightening.

[0019] When the accuracy remains unchanged, locating pins are used to fix the nut seat and bearing seat. The locating pins are set diagonally to control two degrees of freedom.

[0020] When the accuracy changes, repeat steps S101 and S102 to adjust the upper busbar and the side busbar until the accuracy remains constant.

[0021] S2. After the feed mechanism is assembled, it begins the feed motion, and dynamic adjustments are made during the movement:

[0022] S201. Use a dial indicator to monitor the accuracy of the lower busbar and the side busbar in real time, and adjust the tightness of the adjusting screws to adjust the accuracy of the lower busbar and the side busbar until the accuracy requirements are met.

[0023] Furthermore, in step S101, the accuracy of the upper busbar is controlled at 0.005 / 1000mm throughout the entire process. The adjustment method of the nut seat after adjustment is: the adjustment shim of the bearing seat after grinding.

[0024] In step S102, the accuracy of the side busbar is controlled at 0.005 / 1000mm throughout. The adjustment method of the nut seat after adjustment is: tap the bearing seat housing and move the whole body left and right to achieve the accuracy requirements.

[0025] The specific steps of step S201 are as follows: During the movement, one reciprocating motion of the ball screw pair is recorded as a set of data, and a total of twenty sets of data are collected. Among them, after each reciprocating motion in the first to fifth sets of data, the accuracy is adjusted by adjusting the screw. After every two reciprocating motions in the sixth to fifteenth sets of data, the accuracy is adjusted by adjusting the screw. The last five sets of data are used for accuracy correction.

[0026] The advantages and technical effects of this invention are as follows: By adopting the above technical solution, the problems of gravity-induced sag caused by the weight of the lead screw and the wobbling caused by the misalignment of the center holes of the two bearing seats during lead screw rotation are solved, ensuring smooth and reliable front-to-back movement of the lead screw. When grinding workpieces, the machine is free from problems such as ripples and tool breakage, greatly improving machine tool performance.

[0027] Employing both static and dynamic adjustment methods, this approach effectively simulates real-world scenarios, providing more accurate precision feedback and closely mimicking actual operational results to ensure overall precision. It also addresses the issue of insufficient data in adjusting the gap between the upper and side busbars, improving the smoothness of their movement. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure provided in Embodiment 1 of the present invention;

[0029] Figure 2 This is a schematic diagram of the vibration damping component structure provided in Embodiment 2 of the present invention;

[0030] Figure 3 This is a schematic diagram of the connection structure between the nut body and the lead screw provided in Embodiment 3 of the present invention;

[0031] Figure 4 This is a schematic diagram of the support structure provided in Embodiment 4 of the present invention;

[0032] Figure 5 This is a schematic diagram of the connection structure between the support member and the positioning part provided in Embodiment 5 of the present invention.

[0033] In the diagram: 1. Slide plate; 2. Ball screw pair; 2-1. Screw; 2-2. Nut body; 3. Support seat; 3-1. Mounting hole; 3-2. Large diameter section; 3-3. Small diameter section; 3-4. Support stepped surface; 4. Connecting component; 4-1. Positioning part; 4-2. Fitting part; 5. Support component; 5-1. Support washer; 5-2. Adjusting screw; 6. Vibration damping component; 6-1. Adjusting nut; 6-2. Elastic element; 6-3. Adjusting shim; 7. Sleeve; 8. Flush screw. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0035] It should be noted that the terms "upper", "lower", "left", "right", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0036] Example 1

[0037] like Figure 1 As shown, this embodiment provides a feed mechanism for a grinding machine, including a slide 1 with a machining tool. A ball screw assembly 2 is disposed within the slide 1 to drive the slide 1 to move on the machine bed. The ball screw assembly 2 includes a lead screw 2-1 disposed between two bearing seats and a nut body 2-2 disposed on the lead screw 2-1. A support seat 3 is disposed within the slide 1, and a connecting member 4 for connecting the slide 1 and the nut body 2-2 is disposed within the support seat 3. The connecting member 4 includes a positioning part 4-1 disposed within the support seat 3 and a fitting part 4-2 sleeved on the outside of the nut body 2-2. Specifically, the fitting part 4-2 is coaxially arranged with the nut body 2-2.

[0038] The support base 3 is provided with a mounting hole 3-1. The opening direction of the mounting hole 3-1 is perpendicular to the moving direction of the nut body 2-2. The positioning part 4-1 is provided in the mounting hole 3-1. The mounting hole 3-1 is provided with a support member 5 connected to the positioning part 4-1 to prevent the positioning part 4-1 from sinking.

[0039] A vibration damping component 6 is provided on the sleeve part 4-2 on the side opposite to the nut body 2-2 to eliminate the lateral vibration of the ball screw pair 2.

[0040] Preferably, the nut body 2-2 is made of copper, which gives the nut body 2-2 strong wear resistance.

[0041] Preferably, when the diameter of the lead screw 2-1 exceeds 80mm, a tapered set screw is provided between the support 3 and the positioning part 4-1.

[0042] Example 2

[0043] like Figure 2 As shown, unlike Embodiment 1, the vibration damping component 6 in this embodiment includes an adjusting nut 6-1 sleeved on the lead screw 2-1. The connecting section of the adjusting nut 6-1 extends into the sleeve portion 4-2. An elastic element 6-2 and an adjusting pad 6-3 are sequentially arranged between the preload end face of the adjusting nut 6-1 and the force-bearing end face of the sleeve portion 4-2. The adjusting nut 6-1 is used to press the elastic element 6-2 and the adjusting pad 6-3 to achieve the optimal preload force and eliminate the lateral vibration of the ball screw assembly 2. When the motor starts, the moving parts have forward kinetic energy when they first move. This energy is transmitted layer by layer, causing the grinding wheel to puncture. The pressing of the elastic element 6-2, the adjusting pad 6-3, and the adjusting nut 6-1 can absorb this kinetic energy and eliminate the lateral vibration of the moving parts. Preferably, the elastic element 6-2 is a disc spring.

[0044] Preferably, the adjusting nut 6-1 is made of copper, which gives the adjusting nut 6-1 strong wear resistance.

[0045] Example 3

[0046] like Figure 3 As shown, unlike Embodiment 1, in this embodiment, a sleeve 7 is provided between the flange end of the nut body 2-2 and the lead screw 2-1. The sleeve 7 is connected to the nut body 2-2 by a flush-slit screw 8 to ensure the concentricity of the threads of the nut body 2-2, the sleeve 7 and the lead screw 2-1.

[0047] Preferably, the sleeve 7 is made of wear-resistant cast iron.

[0048] Example 4

[0049] like Figure 4 As shown, unlike Embodiment 1, the mounting hole 3-1 in this embodiment includes a large-diameter section 3-2 and a small-diameter section 3-3 that are connected. The small-diameter section 3-3 is close to the nut body 2-2. The large-diameter section 3-2 and the small-diameter section 3-3 form a support stepped surface 3-4. The support member 5 is disposed in the large-diameter section 3-2 and supported on the support stepped surface 3-4.

[0050] Specifically, the length of the support member 5 is greater than the diameter of the small diameter segment 3-3.

[0051] Example 5

[0052] like Figure 4As shown, unlike Embodiment 1, the support member 5 in this embodiment is a support washer 5-1, and the support washer 5-1 is connected to the positioning part 4-1 by an adjusting screw 5-2.

[0053] Example 6

[0054] This embodiment provides a method for adjusting the feed mechanism of a grinding machine, including the following steps:

[0055] S1. The feed mechanism undergoes static adjustment during assembly:

[0056] S101. Fix the dial indicator base on the bed guide rail surface, place the indicator head at the upper busbar position of lead screw 2-1, adjust the rear nut seat, and measure and control the accuracy of the upper busbar throughout its entire stroke.

[0057] Specifically, the accuracy of the upper busbar is controlled within 0.005 / 1000mm throughout the entire process. The adjustment method for the nut seat after adjustment is: the adjustment shim of the bearing seat after grinding.

[0058] Among them, the upper busbar refers to the busbar at the 12 o'clock position of the cross section of the lead screw 2-1.

[0059] S102. After the upper busbar measurement is completed, place the dial indicator head at the side busbar position of lead screw 2-1, adjust the rear nut seat, and measure and control the accuracy of the side busbar throughout its entire length.

[0060] Specifically, the accuracy of the side busbar is controlled within 0.005 / 1000mm. The adjustment method for the nut seat after adjustment is: tap the bearing housing and move the whole structure left and right to achieve the accuracy requirements.

[0061] Among them, the side busbar refers to the busbar in the 3 o'clock direction of the cross section of the lead screw 2-1.

[0062] S103. After the upper busbar and side busbar are adjusted, tighten the screws of the nut seat and bearing seat, and then measure the accuracy of the upper busbar and side busbar to check the accuracy and prevent the accuracy from changing after tightening.

[0063] When the accuracy remains unchanged, locating pins are used to fix the nut seat and bearing seat. The locating pins are set diagonally to control two degrees of freedom.

[0064] When the accuracy changes, repeat steps S101 and S102 to adjust the upper busbar and the side busbar until the accuracy remains constant.

[0065] S2. After the feed mechanism is assembled, it begins the feed motion, and dynamic adjustments are made during the movement:

[0066] S201. Use a dial indicator to monitor the accuracy of the lower busbar and the side busbar in real time, and adjust the tightness of the adjusting screw 5-2 to adjust the accuracy of the lower busbar and the side busbar until the accuracy requirements are met.

[0067] Specifically, during the motion, one reciprocating motion of the ball screw pair 2 is recorded as one set of data, and a total of twenty sets of data are collected. Among them, after each reciprocating motion in the first to fifth sets of data, the accuracy is adjusted by adjusting screw 5-2. After every two reciprocating motions in the sixth to fifteenth sets of data, the accuracy is adjusted by adjusting screw 5-2. The last five sets of data are used for accuracy correction.

[0068] The lower busbar refers to the busbar at the 6 o'clock position of the cross section of lead screw 2-1. The side busbar refers to the busbar at the 3 o'clock position of the cross section of lead screw 2-1.

[0069] In its initial state, the upper and side busbars of the lead screw 2-1 are already adjusted. Due to its own weight, the lead screw 2-1 tends to sag slightly in the middle position during rotation, with a maximum sag of approximately 0.05mm, and also exhibits a wobbling phenomenon during rotation. When using this device, the lead screw 2-1 initially remains stable, and its forward movement is unaffected. Upon reaching the middle position, the lead screw 2-1 tends to shift downwards. At this point, the support washer 5-1 is fixed to the positioning part 4-1 by the adjusting screw 5-2, preventing the nut body 2-2 from shifting downwards with the lead screw 2-1 and maintaining its original positional accuracy as it continues to advance. In the middle position, there is always a force that balances the weight of the lead screw 2-1, preventing it from sags and ensuring accurate feed precision.

[0070] The 0.05mm sag on lead screw 2-1 refers to its central position; it should also be adjusted to 0.05mm when lifted upwards. This adjustment can be changed at any time using adjusting screw 5-2, as the upward force will vary depending on the season and operating environment. Specific adjustments can be made during grinding. When large ripples and vibrations occur during grinding, the tightening of adjusting screw 5-2 should be increased. When small chips appear during grinding, the tightening of adjusting screw 5-2 should be decreased. After adjustment, the position can be fixed with a tapered set screw to ensure stable long-term operation of the machine tool.

[0071] By adopting the above technical solution, the problems of gravity-induced sagging caused by the weight of the lead screw 2-1 and the wobbling caused by the misalignment of the center holes of the two bearing seats during the rotation of the lead screw 2-1 were solved, ensuring smooth and reliable operation of the lead screw 2-1. When grinding workpieces, the machine operates without ripples or tool breakage, greatly improving machine tool performance.

[0072] Employing both static and dynamic adjustment methods, this approach effectively simulates real-world scenarios, providing more accurate precision feedback and closely mimicking actual operational results to ensure overall precision. It also addresses the issue of insufficient data in adjusting the gap between the upper and side busbars, improving the smoothness of their movement.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A feed mechanism for a grinding machine, comprising a slide on which a machining tool is disposed, wherein a ball screw assembly for moving the slide on a machine bed is disposed within the slide, the ball screw assembly comprising a lead screw disposed between two bearing seats and a nut body disposed on the lead screw, characterized in that, The slide plate is provided with a support base, and the support base is provided with a connecting member for connecting the slide plate and the nut body. The connecting member includes a positioning part provided in the support base and a sleeve part sleeved on the outside of the nut body. The support base is provided with a mounting hole, the opening direction of the mounting hole is perpendicular to the moving direction of the nut body, the positioning part is provided in the mounting hole, and a support component connected to the positioning part to prevent the positioning part from sinking is provided in the mounting hole. The mounting hole includes a large-diameter section and a small-diameter section that are connected. The small-diameter section is closer to the nut body. The large-diameter section and the small-diameter section form a support stepped surface. The support member is disposed in the large-diameter section and supported on the support stepped surface. The length of the support member is greater than the diameter of the small-diameter section. The supporting component is a supporting washer, and the supporting washer is connected to the positioning part by an adjusting screw; A vibration damping component is provided on the sleeve part relative to the nut body to eliminate the lateral vibration of the ball screw pair.

2. The feed mechanism for a grinding machine according to claim 1, characterized in that, The vibration damping component includes an adjusting nut sleeved on the lead screw, the connecting section of the adjusting nut extending into the sleeve, and an elastic element and an adjusting pad sequentially disposed between the pre-tightening end face of the adjusting nut and the force-bearing end face of the sleeve.

3. The feed mechanism for a grinding machine according to claim 1 or 2, characterized in that, A sleeve is provided between the flange end of the nut body and the lead screw, and the sleeve is connected to the nut body by a flush-cut screw.

4. The feed mechanism for a grinding machine according to claim 2, characterized in that, The elastic element is a disc spring.

5. The feed mechanism for a grinding machine according to claim 1, characterized in that, The sleeve part is coaxially arranged with the nut body.

6. A method for adjusting the feed mechanism of a grinding machine as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. The feed mechanism undergoes static adjustment during assembly: S101. Fix the dial indicator base on the bed guide rail surface, place the indicator head on the upper busbar position of the lead screw, adjust the rear nut seat, and measure and control the accuracy of the upper busbar throughout its entire stroke. S102. After the upper busbar measurement is completed, place the dial indicator head on the side busbar of the lead screw, adjust the rear nut seat, and measure and control the accuracy of the side busbar throughout its entire length. S103. After the upper busbar and side busbar are adjusted, tighten the screws of the nut seat and bearing seat, and then measure the accuracy of the upper busbar and side busbar to check the accuracy and prevent the accuracy from changing after tightening. When the accuracy remains unchanged, locating pins are used to fix the nut seat and bearing seat. The locating pins are set diagonally to control two degrees of freedom. When the accuracy changes, repeat steps S101 and S102 to adjust the upper busbar and the side busbar until the accuracy remains constant. S2. After the feed mechanism is assembled, it begins the feed motion, and dynamic adjustments are made during the movement: S201. Use a dial indicator to monitor the accuracy of the lower busbar and the side busbar in real time, and adjust the tightness of the adjusting screws to adjust the accuracy of the lower busbar and the side busbar until the accuracy requirements are met.

7. The adjustment method according to claim 6, characterized in that, In step S101, the accuracy of the upper busbar is controlled at 0.005 / 1000mm throughout the entire process. The adjustment method of the nut seat after adjustment is: the adjustment shim of the bearing seat after grinding. In step S102, the accuracy of the side busbar is controlled at 0.005 / 1000mm throughout. The adjustment method of the nut seat after adjustment is: tap the bearing seat housing and move the whole body left and right to achieve the accuracy requirements. The specific steps of step S201 are as follows: During the movement, one reciprocating motion of the ball screw pair is recorded as a set of data, and a total of twenty sets of data are collected. Among them, after each reciprocating motion in the first to fifth sets of data, the accuracy is adjusted by adjusting the screw. After every two reciprocating motions in the sixth to fifteenth sets of data, the accuracy is adjusted by adjusting the screw. The last five sets of data are used for accuracy correction.

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