A Z-axis feed drive mechanism in a Z-axis feed system

Abstract

The present invention discloses a Z-axis feed drive mechanism in a Z-axis feed system, which relates to the technical field of machine tool drive shafts, including a base, a vertical guide rail fixedly mounted on the base, a slider slidably mounted on the guide rail, a lifting platform fixedly mounted on the slider, a lead screw parallel to the guide rail and passing through the lifting platform mounted on the base, the lead screw being driven by a motor mounted on the base; the bottom end of the base is rotatably mounted on a beam fixedly connected to the machine tool; bearings matching the lead screw are fixedly mounted at positions corresponding to the bottom end of the lead screw on the base; an insert is slidably mounted on the output shaft of the motor along its axial direction, and a slot matching the insert is provided at the top end of the lead screw. When an operator detects the degree of wear between the lead screw and the lifting platform, he only needs to flip the base first and then push the push plate to disconnect the output shaft of the motor from the lead screw, without having to disassemble the lead screw, which not only improves the convenience of operation but also avoids affecting the fastening effect of fasteners due to disassembly.

Description

Technical Field

[0001] The present invention relates to the technical field of machine tool drive shafts, and in particular to a Z-axis feed drive mechanism in a Z-axis feed system. Background Art

[0002] Three-axis machine tools are the most basic type of CNC machine tool. They utilize three linear motion axes (X, Y, and Z) to achieve workpiece machining. Their core function is to control the linear movement of the tool or workpiece within three dimensions, making them suitable for machining simple geometric shapes. Each of the three axes, X, Y, and Z, is controlled by a separate feed mechanism, achieving varying degrees of displacement.

[0003] The Chinese invention patent with announcement number CN104493617B discloses a Z-axis feed system, including a power spindle device and a Z-axis feed transmission device; a spindle mounting cylinder is provided in the lower left cavity of the spindle box of the power spindle device, the spindle is installed in the spindle mounting cylinder, the knife cylinder is installed on the top left side of the spindle box, the servo drive motor is installed on the top right side of the spindle box, and the active synchronous wheel at the output end of the servo drive motor and the driven synchronous wheel at the upper end of the spindle are connected and transmitted through a synchronous belt; in the Z-axis feed transmission device, a Z-axis screw nut pair is provided in the vertical slideway on the left side of the column, and the upper end of the Z-axis screw in the Z-axis screw nut pair is connected to the output shaft of the feed servo motor; the sliders of the linear slide rails on both sides of the vertical slideway are connected to the spindle box; the Z-axis counterweight assembly is installed in the counterweight mounting cavity on the right side of the column, the Z-axis counterweight assembly is connected to one end of the counterweight chain, and the other end of the counterweight chain is connected to the spindle box.

[0004] The Chinese utility model patent with publication number CN204700626U discloses a double-screw integral feeding mechanism that can increase the Z-axis stroke, which includes a horizontally arranged crossbeam, on which a horizontal first guide rail is provided; a saddle, which is slidably mounted on the first guide rail; two parallel second guide rails, which are mounted on the saddle in a vertical direction; two screw rods, which are parallel and mounted on the saddle in a vertical direction, and the bottom ends of the two screw rods are respectively provided with parallel telescopic devices; two sliders, which are threadedly connected to the two screw rods in a one-to-one correspondence, and the two sliders are also slidably connected to the two second guide rails in a one-to-one correspondence; a spindle ram, which is connected to the two sliders; a spindle, which is mounted on the spindle ram; two motors, which are respectively driven and connected to the two screw rods in a one-to-one correspondence to make the spindle ram move in the vertical direction.

[0005] The existing Z-axis feed drive mechanism utilizes a ball screw and a saddle for transmission. Over time, the saddle inevitably wears out. This wear can lead to significant feed errors. Therefore, inspectors must regularly remove the ball screw and saddle for testing to ensure that the friction between them remains below a specified value. Existing Z-axis feed drive mechanisms are difficult to disassemble, and repeated disassembly can compromise the securement of fasteners. Summary of the Invention

[0006] The object of the present invention is to provide a Z-axis feed drive mechanism in a Z-axis feed system to solve the above-mentioned deficiencies in the prior art.

[0007] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: a Z-axis feed drive mechanism in a Z-axis feed system, comprising a base, a vertical guide rail fixedly mounted on the base, a slider slidably mounted on the guide rail, a lifting platform fixedly mounted on the slider, a lead screw parallel to the guide rail and passing through the lifting platform mounted on the base, the lead screw being driven by a motor mounted on the base; the bottom end of the base is rotatably mounted on a beam fixedly connected to the machine tool through a pin shaft; bearings matching the lead screw are fixedly mounted at positions corresponding to the bottom end of the lead screw on the base; an insert is slidably mounted on the output shaft of the motor along its axial direction, and a slot matching the insert is provided at the top end of the lead screw.

[0008] As a preferred technical solution of the present invention, a first supporting block for supporting the base is fixedly mounted on the crossbeam.

[0009] As a preferred technical solution of the present invention, a second supporting block is slidably mounted on the bottom surface of the base. When the second supporting block is in contact with the crossbeam, the lead screw is in a vertical state.

[0010] As a preferred technical solution of the present invention, a gear is fixedly sleeved on the bottom end of the lead screw, and a rack corresponding to the position of the gear is fixedly mounted on the second supporting block.

[0011] As a preferred technical solution of the present invention, the cross-section of the plug block is a regular hexagon, a support plate is fixedly installed on the top of the plug block, and a round pin is rotatably installed on the support plate; a control plate is installed on the output shaft of the motor along its radial sliding direction, and an inclined groove is provided on the control plate to cooperate with the round pin.

[0012] As a preferred technical solution of the present invention, the top surface of the slider is a horizontal plane, and marking lines corresponding to the top surface of the slider are provided on the base and the guide rail.

[0013] As a preferred technical solution of the present invention, a limit block that cooperates with the top of the screw is fixedly installed on the base, a through slot that cooperates with the control board is opened on the limit block, and a push plate corresponding to the position of the control board is slidably installed on the through slot.

[0014] As a preferred technical solution of the present invention, a protection unit for protecting the lead screw is installed between the lifting platform and the bearing, and the protection unit includes a plurality of arc-shaped plates coaxial with the lead screw.

[0015] As a preferred technical solution of the present invention, several arc-shaped plates are arranged in layers, two adjacent arc-shaped plates slide together and the outer wall of the inner arc-shaped plate fits with the inner wall of the outer arc-shaped plate; the bottom of the bottom arc-shaped plate is fixedly connected to the bearing, and the top of the top arc-shaped plate is fixedly connected to the lifting platform.

[0016] As a preferred technical solution of the present invention, a hook is fixedly installed on the inner wall of the bottom curved plate; a hanging rod is fixedly installed on the inner wall of the top curved plate, and hooks and hanging rods with staggered vertical positions are fixedly installed on the inner walls of the remaining curved plates, and the position of the hanging rod on the upper curved plate corresponds to the position of the hook on the lower curved plate; a vertical rubber strip is provided on the inner wall of the bottom curved plate corresponding to the position of the upper hanging rod, and the surface of the rubber strip is regularly concave and convex.

[0017] In the above technical solution, the present invention provides a Z-axis feed drive mechanism in a Z-axis feed system, whose base can be flipped 90 degrees relative to the machine tool. During operation, the driving screw is in a vertical state. After flipping the base 90 degrees, the screw is in a horizontal state. When the operator checks the degree of wear between the screw and the lifting platform, he only needs to flip the base first and then push the push plate to disconnect the output shaft of the motor from the screw. There is no need to disassemble the screw, which not only improves the convenience of operation but also avoids affecting the tightening effect of the fasteners due to disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0019] Figure 1 This is a first perspective view of the Z-axis feed drive mechanism in the Z-axis feed system in Example 1;

[0020] Figure 2 This is a second perspective view of the Z-axis feed drive mechanism in the Z-axis feed system in Example 1;

[0021] Figure 3 1 is a front view of the Z-axis feed drive mechanism in the Z-axis feed system in Example 1;

[0022] Figure 4 for Figure 3A magnified schematic diagram of point A in the middle;

[0023] Figure 5 Schematic diagram of the three-dimensional structure of the plug block, support plate and control board in Example 1;

[0024] Figure 6 Schematic diagram of the structure of the protection unit in Example 2;

[0025] Figure 7 for Figure 6 Enlarged schematic diagram of point B in the middle.

[0026] Description of reference numerals:

[0027] 1. Base; 2. Guide rail; 3. Slider; 4. Lifting platform; 5. Screw; 501. Slot; 6. Motor; 7. Beam; 8. Bearing; 9. Insert block; 10. First supporting block; 11. Second supporting block; 12. Gear; 13. Rack; 14. Support plate; 15. Round pin; 16. Control board; 1601. Bevel groove; 17. Limit block; 1701. Through groove; 18. Push plate; 19. Arc plate; 20. Hook; 21. Hanging rod; 22. Rubber strip. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] Example 1

[0030] like Figure 1 As shown, this embodiment provides a Z-axis feed drive mechanism in a Z-axis feed system for a three-axis machine tool, specifically comprising a base 1, on which two mutually parallel guide rails 2 are fixedly mounted. When the machine tool is in operation, the guide rails 2 are in a vertical state, and a slider 3 is slidably mounted on each guide rail 2, and a lifting platform 4 is fixedly mounted on the two sliders 3. A tool head and a driving source for driving the tool head are mounted on the lifting platform 4. A lead screw 5 is mounted on the base 1, which is parallel to the guide rail 2 and passes through the lifting platform 4. The lead screw 5 is driven by a motor 6 mounted on the base 1; the lifting platform 4 includes a nut that cooperates with the lead screw 5, and a plurality of ball bearings are installed in the nut. The specific structure is the existing technology in this field and will not be elaborated in detail here; the bottom end of the base 1 is rotatably mounted on a beam 7 fixedly connected to the machine tool body through a horizontal pin shaft; a bearing 8 that cooperates with the lead screw 5 is fixedly mounted on the base 1 at a position corresponding to the bottom end of the lead screw 5. In the working state, the motor 6 starts and drives the screw 5 to rotate. The screw 5 drives the lifting platform 4 to move along the direction of the guide rail 2 through the force between the screw 5 and the lifting platform 4, thereby driving the tool head on the lifting platform 4 to grind or groove the workpiece along the Z-axis direction.

[0031] like Figure 4 and Figure 5 As shown, an insert block 9 is axially mounted on the output shaft of motor 6, with a regular hexagonal cross-section. A slot 501 is formed at the top of lead screw 5, which mates with insert block 9. A support plate 14 is fixedly mounted on the top of insert block 9, with a round pin 15 rotatably mounted on support plate 14. A control plate 16 is radially mounted on the output shaft of motor 6, perpendicular to round pin 15, and a plate slot corresponding to control plate 16 is formed on the motor shaft. Control plate 16 also has an oblique slot 1601 that mates with round pin 15. When control plate 16 is pushed by an external force, the force between oblique slot 1601 and round pin 15 causes round pin 15, support plate 14, and insert block 9 to move relative to lead screw 5, thereby controlling the relative position of insert block 9 and lead screw 5 and separating insert block 9 from slot 501.

[0032] In the working state, a portion of the insert 9 is inserted into the slot 501. When the motor shaft rotates, the insert 9 will drive the screw 5 to rotate synchronously; in the detection state, the insert 9 is disengaged from the slot 501. When the screw 5 rotates, it will not drive the motor shaft to rotate, that is, the motor shaft will not cause resistance to the rotation of the screw 5.

[0033] like Figure 1 and Figure 2 As shown, a first support block 10 is fixedly mounted on the crossbeam 7 to support the base 1; a second support block 11 is slidably mounted on the bottom surface of the base 1. When the second support block 11 is in contact with the crossbeam 7, the screw 5 is in a vertical state; that is, in the working state, the second support block 11 supports the base 1. When the wear degree between the screw 5 and the lifting platform 4 needs to be tested, the operator turns the base 1 90 degrees and enters Figure 2 In the state shown, the lead screw 5 is horizontal, and the side wall of the base 1 is in contact with the upper surface of the first support block 10, supporting the base 1 via the first support block 10. A gear 12 is fixedly mounted on the bottom end of the lead screw 5, and a rack 13 corresponding to the position of the gear 12 is fixedly mounted on the second support block 11. In the initial state of the second support block 11, the rack 13 and the gear 12 are not in contact. That is, when the lead screw 5 is in operation, the rack 13 and the gear 12 are not in contact.

[0034] The wear between the lead screw 5 and the lifting platform 4 must be kept within a certain range. If the wear reaches a certain level, the wear will increase rapidly with continued use due to the large clearance between the lead screw 5 and the ball bearings within the lifting platform 4. Therefore, the friction between the lead screw 5 and the lifting platform 4 must be kept within a predetermined value. This friction value varies depending on the equipment and processing precision requirements. Within this predetermined friction range, when the lead screw 5 is separated from the motor shaft and subjected to an external torsional force of a predetermined magnitude, the time required for the lead screw 5 to rotate a predetermined number of times is within a predetermined time. For example, it takes 5 seconds for the lead screw 5 to rotate 2 times. If the friction between the lead screw 5 and the lifting platform 4 exceeds this predetermined value, when the lead screw 5 is separated from the motor shaft and subjected to an external torsional force of a predetermined magnitude, the increased friction will cause the lead screw 5 to rotate 2 times in more than 5 seconds. Thus, during the inspection process, after the operator separates the screw 5 from the motor shaft, the second support block 11 is kept in the initial position, and then the second support block 11 is released and the timing is started. The weight of the second support block 11 is constant. In this embodiment, the weight of the second support block 11 is 2.5 kg. The second support block 11 and the rack 13 descend synchronously under the action of gravity. The rack 13 enters a state of meshing with the gear 12, and drives the gear 12 and the screw 5 to rotate. The screw 5 synchronously drives the lifting platform 4 to move horizontally. When the rack 13 is disengaged from the gear 12, the screw 5 rotates a predetermined number of times, and the operator stops the timing. If the time from the second support block 11 starting to descend to the time the rack 13 is disengaged from the gear 12 exceeds the predetermined value, it means that the friction between the screw 5 and the lifting platform 4 exceeds the predetermined value and maintenance is required. If the time does not exceed the predetermined value, the friction between the screw 5 and the lifting platform 4 does not exceed the predetermined value and maintenance is temporarily not required.

[0035] The top surface of the slider 3 is horizontal when in operation, and both the base 1 and the guide rail 2 are provided with markings corresponding to the top surface of the slider 3. Before inspecting the wear between the lead screw 5 and the lifting platform 4, the lead screw 5 is first rotated by the motor 6 to move the slider 3 relative to the base 1 until the top surface of the slider 3 is flush with the markings.

[0036] like Figure 4As shown, the base 1 is fixedly mounted with a stopper 17 that engages with the top of the lead screw 5. The stopper 17 is provided with a through slot 1701 that engages with the control panel 16. A push plate 18 is slidably mounted on the through slot 1701, corresponding to the position of the control panel 16. When the top surface of the slider 3 is flush with the marking line, the through slot 1701 is flush with the plate slot on the motor shaft, i.e., the push plate 18 is flush with the position of the control panel 16. In this state, the operator flips the base 1 90° and pushes the push plate 18. This pushes the control panel 16, separating the insert 9 from the slot 501, thereby enabling the wear between the lead screw 5 and the lifting platform 4 to be tested. After the test is complete, the operator resets the second support block 11, and the lifting platform 4 is also reset simultaneously. The insert 9 is reinserted into the slot 501 under the action of gravity. The round pin 15 and the support plate 14 descend synchronously with the insert 9, and the control panel 16 is reset under the action of the round pin 15.

[0037] Since a large amount of dust is generated when the machine tool processes wood, and the wood cannot be directly sprayed with water to reduce dust, some dust will come into contact with the lead screw 5 and remain in the thread groove of the lead screw 5, which will undoubtedly increase the wear between the lead screw 5 and the lifting platform 4. To alleviate this problem, the following design is implemented in this embodiment.

[0038] like Figure 2 As shown, a protective unit for protecting the lead screw 5 is installed between the lifting platform 4 and the bearing 8. The protective unit includes several arc-shaped plates 19 coaxial with the lead screw 5. The arc-shaped plates 19 are arranged in layers, with adjacent arc-shaped plates 19 slidingly engaged, and the outer wall of the inner arc-shaped plate 19 abutting the inner wall of the outer arc-shaped plate 19. The bottom of the bottom-most arc-shaped plate 19 is fixedly connected to the bearing 8, and the top of the top-most arc-shaped plate 19 is fixedly connected to the lifting platform 4. In this way, when the equipment is operating, the arc-shaped plates 19 block the dust generated, reducing the dust contacting the lead screw 5. Adjacent arc-shaped plates 19 cooperate with each other through sliding grooves and slide bars to achieve sliding in a predetermined direction.

[0039] Example 2

[0040] Based on the previous embodiment, Figure 6 and Figure 7As shown, in this embodiment, a hook 20 is fixedly installed on the inner wall of the bottom curved plate 19; a hanging rod 21 is fixedly installed on the inner wall of the top curved plate 19, and the hanging rod 21 includes a vertical section and a horizontal section located at the end of the vertical section, and the upper horizontal section is fixedly connected to the inner wall of the curved plate 19; except for the bottom and top curved plates 19, hooks 20 and hanging rods 21 are fixedly installed on the inner walls of the remaining curved plates 19, and the hooks 20 and hanging rods 21 on the same curved plate 19 are staggered in the vertical direction, and the position of the hanging rod 21 on the upper curved plate 19 corresponds to the position of the hook 20 on the lower curved plate 19; a vertical rubber strip 22 is provided on the inner wall of the bottom curved plate 19 corresponding to the upper hanging rod 21, and the surface of the rubber strip 22 is regularly concave and convex. When the lifting platform 4 is at the top of its vertical travel, each hanging rod 21 is in contact with the corresponding hook 20 below it. That is, the weight of the lower curved plate 19 acts on the upper hanging rod 21 through the hook 20. In this way, when the lifting platform 4 descends, the second curved plate 19 from the bottom to the top descends relative to the bottom curved plate 19, while the relative positions of the remaining curved plates 19 remain unchanged until the hanging rod 21 on the second curved plate 19 from the bottom to the top is in contact with the top surface of the bottom curved plate 19. As the lifting platform 4 continues to descend, the third curved plate 19 from the bottom to the top begins to descend relative to the bottom curved plate 19.

[0041] It should be noted that the protective unit in this embodiment not only protects the lead screw 5 but also mitigates the vibration transmitted from the cutter head to the lifting platform 4 during operation, reducing the relative vibration between the lifting platform 4 and the lead screw 5, and further alleviating wear on the lifting platform 4 and the lead screw 5. Specifically, the cutter head transmits the vibration to the lifting platform 4, which in turn transmits the vibration to each curved plate 19. The rubber strip 22 cushions the bottom hanging rod 21, thereby providing a buffering effect on each curved plate 19 and the lifting platform 4 as a whole. At the same time, the protective unit can also transmit the vibration to the bearing 8, causing the lifting platform 4 and the lead screw 5 to produce vibrations of similar frequency, reducing wear between them.

[0042] Traditional shock absorption methods either increase the horizontal force between the guide rail 2 and the slider 3 or increase the counterweight on the lifting platform 4. However, either method will increase the load on the motor 6, which is not conducive to energy saving, and the load on the screw 5 will also increase, resulting in a poor effect in alleviating wear. In this embodiment, there is no need to increase the horizontal force between the guide rail 2 and the slider 3, nor is there any need to increase the counterweight on the lifting platform 4. Regardless of the height of the lifting platform 4, the vibration can be alleviated and part of the vibration can be transferred to the bearing 8. In addition, during the detection process, the protection unit does not significantly increase the load on the screw 5, ensuring the accuracy of the detection.

[0043] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A Z-axis feed drive mechanism in a Z-axis feed system, comprising a base (1), a vertical guide rail (2) fixedly mounted on the base (1), a slider (3) slidably mounted on the guide rail (2), a lifting platform (4) fixedly mounted on the slider (3), a lead screw (5) parallel to the guide rail (2) and passing through the lifting platform (4) mounted on the base (1), the lead screw (5) being driven by a motor (6) mounted on the base (1), and characterized in that: The bottom end of the base (1) is rotatably mounted on a beam (7) fixedly connected to the machine tool via a pin shaft; a bearing (8) that cooperates with the lead screw (5) is fixedly mounted on the base (1) at a position corresponding to the bottom end of the lead screw (5); an insert (9) is slidably mounted on the output shaft of the motor (6) along its axial direction, and a slot (501) that cooperates with the insert (9) is provided at the top end of the lead screw (5); The cross section of the plug block (9) is a regular hexagon. A support plate (14) is fixedly mounted on the top of the plug block (9). A round pin (15) is rotatably mounted on the support plate (14). A control plate (16) is slidably mounted on the output shaft of the motor (6) along its radial direction. The control plate (16) is provided with an inclined groove (1601) that cooperates with the round pin (15). A limit block (17) is fixedly mounted on the base (1) and matches the top end of the lead screw (5). A through slot (1701) is provided on the limit block (17) and matches the control board (16). A push plate (18) corresponding to the position of the control board (16) is slidably mounted on the through slot (1701). A protection unit for protecting the lead screw (5) is installed between the lifting platform (4) and the bearing (8), and the protection unit includes a plurality of arc-shaped plates (19) coaxial with the lead screw (5); A plurality of arc-shaped plates (19) are arranged in layers, and two adjacent arc-shaped plates (19) are slidably matched and the outer wall of the inner arc-shaped plate (19) fits in contact with the inner wall of the outer arc-shaped plate (19); the bottom of the bottom arc-shaped plate (19) is fixedly connected to the bearing (8), and the top of the top arc-shaped plate (19) is fixedly connected to the lifting platform (4).

2. The Z-axis feed drive mechanism in the Z-axis feed system according to claim 1, characterized in that: A first supporting block (10) for supporting the base (1) is fixedly mounted on the crossbeam (7).

3. The Z-axis feed drive mechanism in the Z-axis feed system according to claim 1, characterized in that: A second supporting block (11) is slidably mounted on the bottom surface of the base (1); when the second supporting block (11) is in contact with the crossbeam (7), the lead screw (5) is in a vertical state.

4. The Z-axis feed drive mechanism in the Z-axis feed system according to claim 1, characterized in that: The bottom end of the lead screw (5) is fixedly sleeved with a gear (12), and the second supporting block (11) is fixedly mounted with a rack (13) corresponding to the position of the gear (12).

5. The Z-axis feed drive mechanism in the Z-axis feed system according to claim 4, characterized in that: The top surface of the slider (3) is a horizontal surface, and both the base (1) and the guide rail (2) are provided with marking lines corresponding to the top surface of the slider (3).

6. The Z-axis feed drive mechanism in the Z-axis feed system according to claim 5, characterized in that: A hook (20) is fixedly installed on the inner wall of the bottom curved plate (19); a hanging rod (21) is fixedly installed on the inner wall of the top curved plate (19); hooks (20) and hanging rods (21) are fixedly installed on the inner walls of the remaining curved plates (19) at staggered positions in the vertical direction, and the position of the hanging rod (21) on the upper curved plate (19) corresponds to the position of the hook (20) on the lower curved plate (19); a vertical rubber strip (22) is provided on the inner wall of the bottom curved plate (19) at a position corresponding to the upper hanging rod (21), and the surface of the rubber strip (22) is regularly concave and convex.

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