A small-head screw thread rolling device and an anti-skew thread rolling method

Abstract

The present invention discloses a small head screw thread rolling device, comprising a thread rolling mechanism, a feeding mechanism arranged on the right side of the thread rolling mechanism, a loading mechanism connected to the feeding mechanism at one end and connected to the right side of the thread rolling mechanism at the other end, a feeding mechanism arranged at the lower left side of the thread rolling mechanism, and also comprising an anti-skew mechanism arranged in the loading mechanism and the thread rolling mechanism, and a blocking mechanism arranged at the end of the entrance end of the thread rolling mechanism. The anti-skew mechanism comprises a blocking plate close to one side of the small head screw, a supporting plate cushioned on the lower end face of the small head screw, a first pressure rod pressed on the upper end face of the small head screw, and a second pressure rod pressed on the upper end face of the small head screw, wherein the blocking plate, the supporting plate, and the first pressure rod are used to position the small head screw during feeding to prevent the small head screw from being skewed or bouncing, and the second pressure rod is arranged on the upper side of the thread rolling mechanism to prevent the small head screw from being skewed or bouncing during thread rolling. This solution solves the problem that small head screws cannot be unloaded, and improves the working efficiency and product qualification rate of thread rolling processing.

Description

Technical Field

[0001] The invention relates to the field of screw processing, and in particular to a small-head screw thread rolling device and an anti-skew thread rolling method. Background Art

[0002] For existing standard head screws, the head diameter of the screw is larger than the nominal diameter of the screw. When the difference between the head diameter and the nominal diameter is large, the thread processing is usually carried out by using a vibration plate + nail bridge cutting method.

[0003] However, if Figure 1 As shown, it is a cylindrical head machine screw. The characteristics of this screw are that the head diameter D1 is equal to the nominal diameter D2 of the thread (the nominal diameter of the thread, except for the pipe thread, which uses the inner diameter of the through pipe as the nominal diameter, the nominal diameter of other threads is the major diameter of the thread as the nominal diameter), and the thread length tolerance is relatively small. We call this screw a small head screw 1. In actual processing, the major diameter is generally smaller than the nominal diameter. The common processing calculation formula is: major diameter = nominal diameter - (0.13~0.15)P. This difference is formed when the tool cuts the material, and this difference is also the tolerance.

[0004] The existing small-head screws have the following defects: when rolling the threads (referring to rolling the threads) with a rolling machine, due to the small head diameter, the lower support surface is insufficient, the material is not cut smoothly, the nail bridge is stuck, the screw is skewed, and the material cannot be cut. It is impossible to use the vibration plate + nail bridge cutting method for thread processing.

[0005] In response to these problems, we have invented a small-head screw thread rolling device and an anti-skew thread rolling method to solve the above-mentioned defects. Summary of the invention

[0006] The invention aims to solve the problem that when the existing small head screws are rolled with a thread rolling machine, the lower support surface is insufficient, the material is not cut smoothly, the nail bridge is stuck, the screw is skewed, and the material cannot be cut, and the vibration plate + nail bridge cutting method cannot be used for thread processing. The specific solution is as follows:

[0007] A small head screw thread rolling device includes a thread rolling mechanism, a feeding mechanism arranged on the right side of the thread rolling mechanism, a loading mechanism connected to the feeding mechanism at one end and connected to the inlet end of the right side of the thread rolling mechanism at the other end, a discharging mechanism arranged below the outlet end on the left side of the thread rolling mechanism, and also includes an anti-skew mechanism arranged in the feeding mechanism and the thread rolling mechanism, and a material blocking mechanism arranged at the end of the inlet end of the thread rolling mechanism. The anti-skew mechanism includes a blocking plate close to one side of the small head screw, a supporting plate cushioned on the lower end face of the small head screw, a first pressure rod pressed on the upper end face of the small head screw, and a second pressure rod pressed on the upper end face of the small head screw, wherein the blocking plate, the supporting plate, and the first pressure rod are arranged in the feeding mechanism, and are used to position the small head screw during feeding, and prevent the small head screw from being skewed or bouncing, and the second pressure rod is arranged on the upper side of the thread rolling mechanism, and is used to prevent the small head screw from being skewed or bouncing during thread rolling. The material blocking mechanism is a material blocking rod.

[0008] Furthermore, the thread rolling mechanism includes a movable thread rolling plate assembly arranged at the front side of the machine tool, and a fixed thread rolling plate assembly arranged opposite to the movable thread rolling plate assembly and fixed at the rear side of the machine tool.

[0009] Furthermore, the feeding mechanism includes a vibration plate and a material guide tube. The vibration plate is arranged on the right side of the machine tool. The feeding end of the material guide tube is connected to the vibration plate, and the discharging end of the material guide tube is connected to the feeding mechanism. The inner diameter of the material guide tube matches the head diameter of the small head screw.

[0010] Furthermore, the feeding mechanism includes a feeding rail and a pusher knife located in the feeding rail. The pusher knife and the movable thread rolling plate assembly are vertically arranged. The top of the pusher knife is the discharge end port of the guide tube. The front end of the pusher knife is close to the side of the rod body of the small-head screw in the feeding rail. The pusher knife moves back and forth in the feeding rail, and pushes the small-head screws that fall vertically from the discharge end port of the guide tube into the thread rolling mechanism one by one.

[0011] Furthermore, the feeding rail is composed of a rail plate and a right side surface of a fixed rolling plate assembly.

[0012] Furthermore, the pusher knife is L-shaped in appearance, and a rectangular notch is provided at the front lower part thereof.

[0013] Furthermore, the baffle is an arc-shaped elastic sheet, whose arc surface is parallel to the Y plane, the tail end of the baffle is fixed on the machine tool, the front end of the baffle is tightly clamped on the small head side of the small head screw in the loading rail, and moves toward the movable rubbing plate assembly together with the small head screw along with the push knife.

[0014] Furthermore, the support plate is an inverted T-shape, including a support plate and a fixing seat for fixing the support plate, the fixing seat is fixed on the machine tool, the support plate is located in the rectangular notch of the push knife and is parallel to the bottom of the loading rail, the upper end of the support plate supports the lower end face of the small head screw, one side of the support plate is close to the side of the rectangular notch, and the other side of the support plate is close to the rolling surface of the movable rolling plate assembly.

[0015] Furthermore, the first pressure rod is fixed to the fixed screw of the fixed rolling plate assembly, the second pressure rod is fixed to the machine tool, and the discharge end of the material guide pipe is fixed to the fixed screw of the fixed rolling plate assembly through a fixed bracket. The material blocking rod is fixed to the fixed screw of the movable rolling plate assembly.

[0016] Based on the above-mentioned anti-skew thread rolling method of the small head screw thread rolling device, the following steps are performed:

[0017] Step 1, the feeding end of the guide pipe is connected to the vibration plate, the discharging end of the guide pipe is vertically fixed above the pusher, and the gap between the discharging end and the top of the pusher is less than half of the total length of the small head screw; the outer diameter of the head of the small head screw matches the inner diameter of the guide pipe, and the small head screws in the guide pipe move one by one to the discharging end;

[0018] Step 2, when the front end of the pusher moves back to outside the discharge port, the small head screw exposed from the discharge port automatically falls into the loading rail;

[0019] Step 3, the lower end surface of the small head screw in the feeding rail abuts against the upper side of the support plate of the support sheet, the rear side of the rod body of the small head screw abuts against the front end of the pusher, and the front side of the small head of the small head screw is clamped by the front end of the baffle;

[0020] Step 4, the small head screw in the feeding rail moves along the feeding rail and the support plate toward the movable rubbing plate assembly under the forward thrust of the push knife. During the whole movement process, the small head screw keeps vertical movement, the upper end of the small head screw abuts against the first pressure rod, the front side of the small head screw moves forward together with the baffle plate and the rear side of the small head screw moves forward together with the push knife. When the small head screw abuts against the rubbing surface of the entrance end of the movable rubbing plate assembly, the front end of the baffle plate leaves the front side of the small head of the small head screw, and the small head screw moves out of the feeding rail but remains on the end of the support plate, and the rear side of the small head screw continues to abut against the push knife.

[0021] Step 5, after the small head screw abuts against the thread rolling surface of the entrance end, the front and rear sides of the rod body of the small head screw are clamped by the thread rolling surface and the pusher at the same time, and the small head screw follows the leftward rubbing force of the movable thread rolling plate assembly, enters between the fixed thread rolling plate assembly and the movable thread rolling plate assembly, and starts the thread rolling process;

[0022] Step 6, during the thread rolling process, the upper end of the small head screw abuts against the second pressure rod to ensure that the small head screw will not be skewed or bounced when rolling. At the same time, the stopper rod on the right side of the movable thread rolling plate assembly can prevent the small head screw from rebounding when the movable thread rolling plate assembly moves left and right;

[0023] Step 7, after the thread rolling process is completed, the small head screw automatically falls into the unloading mechanism located at the lower left of the outlet end of the fixed thread rolling plate assembly.

[0024] In summary, the technical solution of the present invention has the following beneficial effects:

[0025] This solution solves the problem that when the existing small-head screws are threaded with a thread rolling machine, the material cannot be cut due to the small head diameter, insufficient lower support surface, uneven feeding, nail bridge jamming, and screw skew, and the vibration plate + nail bridge cutting method cannot be used for thread processing. The guide tube of this solution replaces the nail bridge structure of the existing method, effectively solving the problem that the small-head screws cannot be cut. The inner diameter of the guide tube is slightly larger than the outer diameter of the small head of the small-head screw, ensuring that the small-head screws in the tube move one after another along the inner wall of the tube. The structure of the material end of the guide tube is perpendicular to the feeding rail track, ensuring that the small-head screw is in a vertical state when it automatically enters the feeding rail track. The structural design of the push knife, baffle, support plate, and first pressure rod, as well as the simultaneous action on the small-head screw around, ensure that the small-head screw moves vertically along the feeding rail track to the movable thread rolling plate assembly in the feeding mechanism without skewing or bouncing, thereby enhancing the stability of the movement of the small-head screw. The structural design of the second pressure rod and the material blocking rod ensures that the small head screw will not be skewed, bounced, or rebound during the thread rolling process, thereby improving the work efficiency and product qualification rate of the small head screw thread rolling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only part of the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative labor.

[0027] Figure 1 It is a schematic diagram of the structure of the small head screw of the present invention;

[0028] Figure 2 A top view of a small head screw thread rolling device according to the present invention;

[0029] Figure 3 This is a structural diagram of a pusher knife and a support plate of a small-head screw thread rolling device of the present invention.

[0030] Description of reference numerals:

[0031] 1- small head screw, 2- baffle, 3- support plate, 4- first pressure rod, 5- second pressure rod, 6- machine tool, 7- movable rubbing plate assembly, 8- fixed rubbing plate assembly, 9- vibration plate, 10- material guide pipe, 11- feeding rail, 12- pushing knife, 13- material baffle rod, 14- unloading mechanism, 31- support plate, 32- fixed seat, 71- rubbing surface, 87- fixed screw, 101- fixed bracket, 111- rail plate, 121- rectangular notch, D1- head diameter, D2- nominal diameter, D3- inner diameter. DETAILED DESCRIPTION

[0032] The technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In order to help understand the content of this patent, Figure 2 For reference, the left side in the figure is defined as left, the right side in the figure is defined as right, the top in the figure is defined as front, and the bottom in the figure is defined as back.

[0034] like Figures 1 to 3 As shown, a small head screw thread rolling device includes a thread rolling mechanism, a feeding mechanism arranged on the right side of the thread rolling mechanism, a feeding mechanism connected to the feeding mechanism at one end and connected to the inlet end of the right side of the thread rolling mechanism at the other end, a feeding mechanism 14 arranged below the outlet end on the left side of the thread rolling mechanism, and also includes an anti-skew mechanism arranged in the feeding mechanism and the thread rolling mechanism, and a material blocking mechanism arranged at the end of the inlet end of the thread rolling mechanism. Preferably, the material blocking mechanism is a material blocking rod 13. The anti-skew mechanism includes a blocking piece 2 close to one side of the small head screw 1, a supporting piece 3 cushioned on the lower end face of the small head screw 1, a first pressing rod 4 pressed on the upper end face of the small head screw 1, and a second pressing rod 5 pressed on the upper end face of the small head screw 1, wherein the blocking piece 2, the supporting piece 3, and the first pressing rod 4 are arranged in the feeding mechanism, and are used to position the small head screw 1 during feeding, and prevent the small head screw 1 from being skewed or bounced, and the second pressing rod 5 is arranged on the upper side of the thread rolling mechanism, and is used to prevent the small head screw 1 from being skewed or bounced during thread rolling.

[0035] Furthermore, the thread rolling mechanism includes a movable thread rolling plate assembly 7 arranged at the front side of the machine tool 6, and a fixed thread rolling plate assembly 8 arranged opposite to the movable thread rolling plate assembly 7 and fixed at the rear side of the machine tool 6.

[0036] Furthermore, the feeding mechanism includes a vibration plate 9 and a material guide tube 10. The vibration plate 9 is arranged on the right side of the machine tool 6. The feeding end of the material guide tube 10 is connected to the vibration plate 9, and the discharging end of the material guide tube 10 is connected to the feeding mechanism. The inner diameter D3 of the material guide tube 10 matches the head diameter D1 of the small head screw 1 and satisfies: (D3-D1)≥0.8~1.0mm.

[0037] Furthermore, the feeding mechanism includes a feeding rail 11 and a pusher knife 12 located in the feeding rail 11. The pusher knife 12 is vertically arranged to the movable thread rolling plate assembly 7. The top of the pusher knife 12 is the discharge end port of the guide tube. The front end of the pusher knife 12 is close to the side of the rod body of the small head screw 1 in the feeding rail 11. The pusher knife 12 moves back and forth (that is, moves forward and backward) in the feeding rail 11, and pushes the small head screws 1 that fall vertically from the discharge end port of the guide tube 10 into the thread rolling mechanism one by one through the feeding rail 11.

[0038] Furthermore, the feeding rail 11 is composed of a rail plate 111 and the right side surface of the fixed rolling plate assembly 8 .

[0039] Furthermore, the pusher knife 12 is L-shaped in appearance, and a rectangular notch 121 is provided at the front lower portion thereof.

[0040] Furthermore, the baffle 2 is an arc-shaped elastic sheet, whose arc surface is parallel to the Y plane, and the tail end of the baffle 2 is fixed to the machine tool 6 by screws, and the front end of the baffle 2 is tightly clamped on the side of the small head of the small head screw 1 in the feeding rail 11 (referring to the front side), and moves with the small head screw 1 along with the pusher 12 toward the movable rolling plate assembly 7. The front end length and angle of the baffle 2 are precisely designed so that when the pusher 12 pushes the small head screw 1 close to the movable rolling plate assembly 7, the front end of the baffle 2 leaves the front side of the small head of the small head screw 1.

[0041] Furthermore, the support plate 3 is an inverted T-shape, including a support plate 31 and a fixing seat 32 for fixing the support plate 31, the fixing seat 32 is fixed on the machine tool 6, the support plate 31 is located in the rectangular notch 121 of the push knife 12 and is located parallel to the bottom of the loading rail 11, the upper end of the support plate 31 supports the lower end face of the small head screw 1, one side of the support plate 31 (i.e. the rear side) is close to the side edge (rear side edge) of the rectangular notch 121, and the other side of the support plate 31 (i.e. the front side) is close to the rolling surface 71 of the movable rolling plate assembly 7.

[0042] Furthermore, the first pressure rod 4 is fixed to the fixed screw 87 of the fixed rubbing plate assembly 8, the second pressure rod 5 is fixed to the machine tool 6, the discharge end of the material guide tube 10 is fixed to the fixed screw 87 of the fixed rubbing plate assembly 8 through the fixed bracket 101, and the material blocking rod 13 is fixed to the right fixed screw 87 of the movable rubbing plate assembly 7.

[0043] Based on the above-mentioned anti-skew thread rolling method of the small head screw thread rolling device, the following steps are performed:

[0044] Step 1, set the feeding end of the guide tube 10 to be connected to the vibration plate 9, the discharging end of the guide tube 10 is vertically fixed above the pusher 12, and the gap between the discharging end and the top of the pusher 12 is less than half of the total length of the small head screw 1; the head outer diameter D1 of the small head screw 1 matches the inner diameter D3 of the guide tube 10, and the small head screws 1 in the guide tube 10 move one by one to the discharging end;

[0045] Step 2, when the front end of the pusher 12 retreats to outside the discharge port, the small head screw 1 exposed from the discharge port automatically falls into the loading rail 11;

[0046] Step 3, the lower end surface of the small head screw 1 in the feeding rail 11 abuts against the upper side of the support plate 31 of the support sheet 3, the rear side of the rod body of the small head screw 1 abuts against the front end of the pusher 12, and the front side of the small head of the small head screw 1 is clamped by the front end of the baffle 2;

[0047] Step 4, the small head screw 1 in the feeding rail 11 moves along the feeding rail 11 and the support plate 31 to the movable thread rolling plate assembly 7 under the forward thrust of the push knife 12. During the whole movement process, the small head screw 1 keeps vertical movement, the upper end of the small head screw 1 abuts against the first pressure rod 4, the front side of the small head screw 1 moves forward together with the baffle plate 2 and the rear side of the small head screw 1 moves forward together with the push knife 12. When the small head screw 1 abuts against the thread rolling surface 71 at the entrance end of the movable thread rolling plate assembly 7, the front end of the baffle plate 2 leaves the front side of the small head of the small head screw 1, and the small head screw 1 moves out of the feeding rail 11, but is still on the end of the support plate 31, and the rear side of the small head screw 1 continues to abut against the push knife 12.

[0048] Step 5, after the small head screw 1 abuts against the thread rolling surface 71 at the entrance end, the front and rear sides of the rod body of the small head screw 1 are clamped by the thread rolling surface 71 and the pusher 12 at the same time, and the small head screw 1 follows the leftward rubbing force of the movable thread rolling plate assembly 7, enters between the fixed thread rolling plate assembly 8 and the movable thread rolling plate assembly 7 (that is, is clamped between the two thread rolling surfaces), and starts the thread rolling process;

[0049] Step 6, during the thread rolling process, the upper end of the small head screw 1 abuts against the second pressure rod 5, ensuring that the small head screw 1 will not be skewed or bounced when rolling. At the same time, the stop rod 13 on the right side of the movable thread rolling plate assembly 7 can prevent the rebound of the small head screw 1 when the movable thread rolling plate assembly 7 moves left and right (under normal circumstances, the small head screw 1 moves from right to left, and sometimes the small head screw 1 will stick to the fixed thread rolling plate assembly 8, and the stop rod 13 will work at this time);

[0050] Step 7, after the thread rolling process is completed, the small head screw 1 automatically falls into the unloading mechanism 14 arranged at the lower left of the outlet end of the fixed thread rolling plate assembly 8.

[0051] In summary, the technical solution of the present invention has the following beneficial effects:

[0052] This solution solves the problem that when existing small-head screws are threaded with a thread rolling machine, due to the small head diameter, insufficient lower support surface, uneven feeding, nail bridge jamming, and screw crookedness, the material cannot be cut, and the thread processing cannot be performed using the vibration plate + nail bridge cutting method. The guide tube 10 of the present solution replaces the nail bridge structure of the existing method, effectively solving the problem that the small-head screw 1 cannot be unloaded. The inner diameter D3 of the guide tube 10 is slightly larger than the outer diameter of the small head of the small-head screw 1 (that is, the head diameter D1), ensuring that the small-head screws 1 in the tube move one after another along the inner wall of the tube. The structure in which the material end of the guide tube 10 is perpendicular to the feed rail 11 ensures that the small-head screw 1 is in a vertical state when automatically entering the feed rail 11. The structural design of the push knife 12, the baffle plate 2, the support plate 3, and the first pressure rod 4, as well as the simultaneous action on the small-head screw 1 around, ensure that the small-head screw 1 in the feeding mechanism moves vertically along the feed rail 11 toward the movable rubbing plate assembly 7 without skewing or bouncing, thereby enhancing the stability of the movement of the small-head screw 1. The structural design of the second pressure rod 5 and the material blocking rod 13 ensures that the small head screw 1 will not be skewed, bounced, or rebounded during the thread rolling process, thereby improving the work efficiency and product qualification rate of the thread rolling process of the small head screw 1.

[0053] The above-described implementation methods do not constitute a limitation on the protection scope of the technical solution. Any modification, equivalent replacement and improvement made within the spirit and principle of the above-described implementation methods shall be included in the protection scope of the technical solution.

Claims

1. A small head screw thread rolling device, characterized in that: It includes a thread rolling mechanism, a feeding mechanism arranged on the right side of the thread rolling mechanism, a loading mechanism connected to the feeding mechanism at one end and connected to the inlet end of the right side of the thread rolling mechanism at the other end, a unloading mechanism arranged below the outlet end on the left side of the thread rolling mechanism, and also includes an anti-skew mechanism arranged in the feeding mechanism and the thread rolling mechanism, and a blocking mechanism arranged at the end of the inlet end of the thread rolling mechanism; the anti-skew mechanism includes a blocking piece close to one side of the small head screw, a supporting piece cushioned on the lower end face of the small head screw, a first pressure rod pressed on the upper end face of the small head screw, and a second pressure rod pressed on the upper end face of the small head screw, wherein the blocking piece, the supporting piece and the first pressure rod are arranged in the feeding mechanism, and are used to position the small head screw during feeding to prevent the small head screw from skewing or bouncing, and the second pressure rod is arranged on the upper side of the thread rolling mechanism, and is used to prevent the small head screw from skewing or bouncing during thread rolling; the blocking mechanism is a blocking rod; The thread rolling mechanism comprises a movable thread rolling plate assembly arranged at the front side of the machine tool, and a fixed thread rolling plate assembly arranged opposite to the movable thread rolling plate assembly and fixed at the rear side of the machine tool; The feeding mechanism comprises a feeding rail, a pusher knife located in the feeding rail, the pusher knife and the movable thread rolling plate assembly are arranged vertically, the upper part of the pusher knife is the discharge end port of the guide tube, the front end of the pusher knife is close to the side of the rod body of the small head screw in the feeding rail, the pusher knife moves back and forth in the feeding rail, and pushes the small head screws that fall vertically from the discharge end port of the guide tube into the thread rolling mechanism one by one; The baffle is an arc-shaped elastic sheet, whose arc surface is parallel to the Y plane. The tail end of the baffle is fixed on the machine tool, and the front end of the baffle is tightly clamped on the small head side of the small head screw in the feeding rail, and moves with the pusher knife toward the movable rubbing plate assembly together with the small head screw; The support plate is in an inverted T-shape, including a support plate and a fixing seat for fixing the support plate, the fixing seat is fixed on the machine tool, the support plate is located in the rectangular notch of the pusher knife and is parallel to the lower end of the feed rail, the upper end of the support plate supports the lower end surface of the small head screw, one side of the support plate is close to the side of the rectangular notch, and the other side of the support plate is close to the rolling surface of the movable rolling plate assembly; The first pressure rod is fixed on the fixed screw rod of the fixed rubbing plate assembly; the material blocking rod is fixed on the fixed screw rod of the movable rubbing plate assembly.

2. A small head screw thread rolling device according to claim 1, characterized in that: The feeding mechanism includes a vibration plate and a guide tube. The vibration plate is arranged on the right side of the machine tool. The feeding end of the guide tube is connected to the vibration plate, and the discharging end of the guide tube is connected to the feeding mechanism. The inner diameter of the guide tube matches the head diameter of the small head screw.

3. A small head screw thread rolling device according to claim 2, characterized in that: The feeding rail is composed of a rail plate and a right side surface of a fixed thread rolling plate assembly.

4. A small head screw thread rolling device according to claim 3, characterized in that: The second pressure rod is fixed on the machine tool, and the discharge end of the material guide pipe is fixed on the fixed screw of the rubbing plate assembly through a fixed bracket.

5. A method for preventing crooked thread rolling of a small head screw thread rolling device according to claim 4, characterized in that: Follow these steps: Step 1, the feeding end of the guide pipe is connected to the vibration plate, the discharging end of the guide pipe is vertically fixed above the pusher, and the gap between the discharging end and the top of the pusher is less than half of the total length of the small head screw; the outer diameter of the head of the small head screw matches the inner diameter of the guide pipe, and the small head screws in the guide pipe move one by one to the discharging end; Step 2, when the front end of the pusher moves back to outside the discharge port, the small head screw exposed from the discharge port automatically falls into the loading rail; Step 3, the lower end surface of the small head screw in the feeding rail abuts against the upper side of the support plate of the support sheet, the rear side of the rod body of the small head screw abuts against the front end of the pusher, and the front side of the small head of the small head screw is clamped by the front end of the baffle; Step 4, the small head screw in the feeding rail moves along the feeding rail and the support plate toward the movable rubbing plate assembly under the forward thrust of the push knife. During the whole movement process, the small head screw keeps vertical movement, the upper end of the small head screw abuts against the first pressure rod, the front side of the small head screw moves forward together with the baffle plate and the rear side of the small head screw moves forward together with the push knife. When the small head screw abuts against the rubbing surface of the entrance end of the movable rubbing plate assembly, the front end of the baffle plate leaves the front side of the small head of the small head screw, and the small head screw moves out of the feeding rail but remains on the end of the support plate, and the rear side of the small head screw continues to abut against the push knife. Step 5, after the small head screw abuts against the thread rolling surface of the entrance end, the front and rear sides of the rod body of the small head screw are clamped by the thread rolling surface and the pusher at the same time, and the small head screw follows the leftward rubbing force of the movable thread rolling plate assembly, enters between the fixed thread rolling plate assembly and the movable thread rolling plate assembly, and starts the thread rolling process; Step 6, during the thread rolling process, the upper end of the small head screw abuts against the second pressure rod to ensure that the small head screw will not be skewed or bounced when rolling. At the same time, the stopper rod on the right side of the movable thread rolling plate assembly can prevent the small head screw from rebounding when the movable thread rolling plate assembly moves left and right; Step 7, after the thread rolling process is completed, the small head screw automatically falls into the unloading mechanism located at the lower left of the outlet end of the fixed thread rolling plate assembly.

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