External circulation ball screw

Abstract

The invention relates to the technical field of ball screws, in particular to an external circulation ball screw which comprises a screw body, a threaded groove, a dustproof sealing disc and an external nut shell and further comprises a circulation pipe, a ball control box, a top base, a channel intercepting assembly, a ball limiting assembly, a transverse moving ring, a circulation connecting pipe and light balls. The interior of the circulating pipe communicates with the threaded groove, the ball control box is installed between the ends of the circulating pipe, the channel intercepting assembly is installed in the ball control box, a circulating connecting pipe is installed in the ball control box, and a ball channel is formed between the interior of the circulating connecting pipe and the circulating pipe. The ball limiting assembly is installed between one end in the ball control box and the circulating connecting pipe close to the end. The working efficiency and the printing precision of the 3D printing equipment are fully guaranteed by limiting the balls when the lead screw stops rotating and preventing the balls from continuously moving under the inertia effect.

Description

Technical Field

[0001] The invention relates to the technical field of ball screws, in particular to an external circulation ball screw. Background Art

[0002] Ball screw transmission refers to a screw transmission that uses continuously filled balls as an intermediate between a screw with a spiral groove and a nut to convert the sliding friction between the screw and the nut into rolling friction. Compared with other transmission mechanisms, ball screws have high transmission efficiency, low heat generation, long service life, high positioning accuracy, stable operation, and no creeping at low speeds. One of the biggest features is that it has no self-locking ability and has reversibility of transmission, that is, it can convert rotary motion into linear motion, and also convert linear motion into rotary motion. Ball screws can be divided into external circulation ball screws, internal circulation ball screws, semi-external circulation ball screws, and single-circuit ball screws. The return path of the ball of the external circulation ball screw is located outside the screw, which is suitable for high-load and high-speed scenarios, such as CNC machine tools, laser cutting machines, industrial robots, 3D printing equipment and other devices.

[0003] When an external circulation ball screw is used on a 3D printing device to drive the movement of the nozzle, due to the high movement speed of the external circulation ball screw, when the ball nut drives the nozzle to move to the stop position, the ball nut and the nozzle need to stop at a certain speed. However, under the action of inertia, the ball will continue to roll forward along the circulation pipe, causing the screw to continue to rotate a certain angle. At the same time, the ball nut drives the nozzle of the 3D printing device to continue to move, causing the nozzle to be unable to stop at the recorded stop position. When the 3D printing device continues to start, the nozzle is not in the recorded stop position, so the subsequent printing accuracy of the 3D printing device cannot be guaranteed.

[0004] In order to prevent the ball from moving forward under the action of inertia, which may cause the subsequent printing accuracy of the 3D printing equipment to be unable to be guaranteed, the existing technology often uses a circuit control system to gradually and significantly reduce the speed of the driving screw motor before the nozzle is about to move to a specific position to reduce the inertia of the ball. However, reducing the motor speed in advance will slow down the nut and the nozzle, which means that it will take more time for the nozzle to move a certain distance, which will limit the working efficiency of the 3D printing equipment, especially affecting the efficiency of high-frequency and intermittent printing work.

[0005] Therefore, an external circulation ball screw is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide an external circulation ball screw, which limits the ball when the screw stops rotating to prevent the ball from continuing to move under the action of inertia. This solves the problem that when the external circulation ball screw stops rotating, the ball continues to drive the nozzle to move under the action of inertia, and the screw rotation speed needs to be reduced in advance, resulting in limited working efficiency of the 3D printing equipment. The working efficiency of the 3D printing equipment can be fully guaranteed, and there is no need to adjust the nozzle spraying speed to adapt to the screw rotation speed.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An external circulation ball screw, comprising a screw, a threaded groove, a dustproof sealing disk, an external nut housing, a circulation pipe, a ball control box, a top seat, a channel interception assembly, a ball limit assembly, a traverse ring, a circulation connecting pipe and a lightweight ball, wherein the circulation pipe is mounted on the external nut housing, and the interior of the circulation pipe is communicated with the threaded groove, the ball control box is mounted between the ends of the circulation pipe, the channel interception assembly is mounted inside the ball control box, a circulation connecting pipe is installed inside the ball control box, and the interior of the circulation connecting pipe is connected to the circulation pipe A ball channel is formed between the two, and the ball limit assembly is installed between one end inside the ball control box and the circulation connecting pipe close to the end, the transverse ring is installed at the end of the ball limit assembly, and the outer periphery of the transverse ring is fitted with the channel interception assembly, and the end of the transverse ring is fitted with the end of the circulation connecting pipe. The lightweight balls are arranged in the ball channel and the inner thread groove of the external nut shell. When the screw drive device stops, the channel interception assembly moves up and pushes the transverse ring to move horizontally. The ball limit assembly limits the movement of the lightweight balls when squeezed by the transverse ring.

[0009] Compared with other types of ball screws, the biggest advantage of the external circulation ball screw is that it provides excellent positioning accuracy and large load-bearing capacity, and is suitable for equipment with high precision requirements. For this reason, in 3D printing equipment with high precision requirements, the use of an external circulation ball screw can effectively ensure the 3D printing accuracy. Then, because the external circulation ball screw can move at high speed, it has the following disadvantages: the ball inside the ball nut moves at high speed. When the screw stops rotating, under the action of inertia, the ball has a tendency to continue to move and will produce a slight displacement, which will cause the position control of the 3D printing equipment to be difficult to control. In the prior art, the method of reducing the screw speed in advance is often used to reduce the influence of inertia on the printing accuracy. However, when reducing the screw speed, it is necessary to change the discharge speed of the nozzle synchronously, resulting in a decrease in the efficiency of the 3D printing equipment. At the same time, the control factors increase, which is more likely to have an adverse effect on the printing accuracy. For this reason, the technical solution adopts the method of limiting the ball inside the screw nut when the screw stops rotating, and the screw can be quickly stopped when rotating at high speed by offsetting the inertia effect, and the printing accuracy of the 3D printing equipment is ensured.

[0010] Preferably, the channel interception assembly includes a limit column, a lifting seat, an electromagnet and a magnetic shielding plate, the magnetic shielding plate is installed on the surface of the top seat, the electromagnet is fitted on the bottom of the magnetic shielding plate, the limit column is installed between the bottom of the electromagnet and the ball control box, the lifting seat is arranged inside the ball control box, and the limit column passes through the lifting seat, the two ends of the lifting seat are respectively fitted with two transverse rings, and when the electromagnet power is turned on, the lifting seat moves up along the limit column and pushes the transverse ring to both sides.

[0011] When the screw stops rotating, the synchronous switch connected to the screw drive device disconnects the power supply of the drive device and simultaneously connects the power supply of the channel interception component. The lifting seat is adsorbed and moved upward along the limit seat through the magnetic force of the electromagnet. When the limit seat moves upward, it pushes the transverse movement ring horizontally to both sides. The transverse movement ring is misaligned with the ball channel and prevents the lightweight ball from continuing to pass through the ball channel. By preventing the ball from continuing to move, the printing accuracy of the 3D printing equipment can be effectively guaranteed.

[0012] Preferably, the ball limit assembly includes a limit rod, an arc strip, a connecting rod and an insertion strip, the limit rod is installed at one end inside the ball control box, the arc strips are arranged side by side in the corresponding circulation connecting tube, and the inner circumference of the circulation connecting tube is provided with an arc groove adapted to the arc strip, and the arc groove is provided with a through hole with an isosceles trapezoidal cross-section in top view, the side wall of the arc strip is connected with a through rod passing through the through hole, the through rod is located at one end of the outer side of the circulation connecting tube and a docking seat is installed, the side wall of the docking seat is provided with a conical groove, the outer circumference of the through rod is sleeved with a third spring located in the arc groove, the connecting rod is installed on one end of the limit rod close to the transverse ring, the insertion strip is installed at the end of the connecting rod, and the side wall of the insertion strip is provided with a conical protrusion arranged at the same height as the conical groove.

[0013] When the transverse ring moves horizontally under the action of the channel interception assembly, it will squeeze the ball limit assembly, thereby causing the ball limit assembly to move horizontally. When the insert strip is detached from the docking seat, the through rod can swing horizontally, thereby allowing the arc strip to move into the arc groove and fit tightly around the lightweight ball after changing its angle, thereby limiting the lightweight ball in the ball channel. By assisting in improving the limiting effect of the lightweight ball, the lightweight ball is prevented from continuing to move under the action of inertia, thereby further improving the printing accuracy of the 3D printing equipment.

[0014] Preferably, the lifting seat includes a box body, an iron block, a first spring and a side plate, the iron block is arranged inside the box body, the first spring is sleeved on the outer periphery of the limiting column, and the first spring abuts between the top of the iron block and the box body, and the side plate is installed on the side wall of the box body.

[0015] When the electromagnet is powered on and subjected to the magnetic force, the iron block squeezes the first spring and moves up to the highest point in the box, and then drives the box up together, so that the box pushes the transverse movement ring to both sides when moving up. After the electromagnet is powered off, the first spring quickly resets and bounces the iron block downward, so that the iron block can be quickly reset, and under the action of the inertia of the iron block, the reset of the box can be accelerated, so that the transverse movement ring can be quickly reset, so as to ensure that the lightweight ball can continue to move in the ball channel, so that the 3D printing equipment can be quickly reset and used later.

[0016] Preferably, both ends of the box body are constructed with arc surfaces, and the radius of the arc surface is equal to the radius of the outer circumference of the transverse ring.

[0017] Under the action of the arc surface, both ends of the box can fit tightly with the transverse ring, ensuring that the lightweight balls can smoothly pass through the inside of the transverse ring in a static state, preventing the transverse ring from shaking when the lightweight balls pass through the inside of the transverse ring, thereby affecting the smooth movement of the lightweight balls.

[0018] Preferably, a second spring is sleeved on the outer periphery of the limiting column, and the second spring abuts between the bottom of the electromagnet and the top of the lifting seat.

[0019] When the lifting seat moves upward as a whole, the second spring will be squeezed. When the electromagnet is powered off, the lifting seat without magnetic force cannot exert pressure on the second spring. At this time, the elastic force of the second spring can accelerate the resetting of the lifting seat, thereby ensuring that the subsequent 3D printing equipment can be started and used smoothly.

[0020] Preferably, the ball limit assembly further comprises an arc block, which is symmetrically mounted on the top and bottom surfaces inside the ball control box, and the surface of the arc block is provided with an arc surface adapted to the outer periphery of the transverse ring.

[0021] The arc block can be used to limit the transverse movement ring to prevent the transverse movement ring from moving excessively, which would cause the limit rod to be over-extruded and the return spring to lose its elasticity.

[0022] Preferably, the limit rod includes a cylinder, a return spring, a sleeve and a sliding rod, the return spring is arranged in the cylinder, the sleeve is arranged inside the cylinder, and the side wall of the sleeve abuts against the end of the return spring, the sliding rod is installed on the side wall of the sleeve, and the sliding rod extends to the outside of the cylinder.

[0023] When in use, the limit rod can provide support for the transverse shift ring from the side away from the box body, and provide thrust for the transverse shift ring when the transverse shift ring needs to be reset later, ensuring that the transverse shift ring can be reset smoothly, allowing the lightweight balls to circulate smoothly through the ball channel.

[0024] Preferably, a round rod located inside the return spring is installed on the inner circumference of the cylinder, and a cylindrical groove adapted to the round rod is constructed on the inner circumference of the slide rod.

[0025] Under the action of the round rod, the moving trajectory of the slide bar can be restricted to ensure the horizontal and linear movement of the slide bar, effectively improving the structural strength of the limit rod.

[0026] Preferably, the lightweight ball includes a steel shell and a lightweight metal ball, and the steel shell is wrapped and fitted around the outer circumference of the lightweight metal ball.

[0027] The lightweight metal ball is made of titanium, the density of which is about 4.5g / cm 3 , while the density of steel is about 7.8g / cm 3 The melting point of titanium is about 1,668°C, which is higher than the melting point of steel. After the lightweight metal ball is made, the steel shell is wrapped around the outer periphery of the lightweight metal ball by casting. Under the premise of ensuring the strength of the lightweight ball, the mass of the lightweight ball can be reduced, thereby reducing the adverse effects of inertia on the printing accuracy of the 3D printing equipment. The outer steel shell can be positioned with the help of magnetic force, thereby avoiding the tendency of the lightweight ball to continue to move.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention provides a channel interception assembly and a transverse shift ring. When the power supply of the screw drive device is disconnected, the power supply of the channel interception assembly is synchronously turned on. The channel interception assembly moves upward through the magnetic force and pushes the transverse shift ring to both sides, so that the transverse shift ring and the ball channel are misaligned, thereby preventing the lightweight ball from continuing to pass through the ball channel and preventing the lightweight ball from continuing to move under the action of inertia, causing the nozzle to continue to move with the external nut housing. This can achieve the goal of quickly stopping the rotation of the screw and effectively ensure the printing accuracy of the 3D printing equipment.

[0030] 2. The present invention provides a ball limit assembly and a transverse movement ring. When the transverse movement ring moves horizontally due to the action of the channel interception assembly, the ball limit assembly can be activated by an extrusion action, so that the arc bar in the ball limit assembly can move into the arc groove. After the arc bar adaptively rotates, it fits tightly on the outer periphery of the lightweight ball, limits the lightweight ball in the ball channel, and assists in improving the limiting effect of the lightweight ball, preventing the lightweight ball from continuing to move under the action of inertia, thereby further improving the printing accuracy of the 3D printing equipment.

[0031] 3. The lightweight balls provided in the present invention can significantly reduce weight while keeping the overall volume unchanged and ensuring structural strength. Therefore, the lightweight balls have less inertia when moving and are easier to stop, which helps to reduce the burden on the channel interception component and the ball limit component, thereby effectively extending the overall service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 is a cross-sectional view of the ball control box of the present invention;

[0034] Figure 3 A cross-sectional view of the ball control box of the present invention in a static state;

[0035] Figure 4 For the present invention Figure 3 A magnified view of the structure at center;

[0036] Figure 5 A cross-sectional view of the ball control box of the present invention in the operating state;

[0037] Figure 6 It is a structural schematic diagram of the lifting seat of the present invention;

[0038] Figure 7 is a cross-sectional schematic diagram of a limiting rod of the present invention;

[0039] Figure 8 It is a cross-sectional view of the lightweight ball of the present invention.

[0040] In the figure: 1, screw rod; 2, thread groove; 3, dustproof sealing disk; 4, external nut housing; 5, circulation pipe; 6, ball control box; 7, top seat; 8, channel interception assembly; 81, limit column; 82, lifting seat; 821, box body; 8211, arc surface; 822, iron block; 823, first spring; 824, side plate; 83, second spring; 84, electromagnet; 85, magnetic shielding plate; 9, ball limit assembly; 91, limit rod; 911, cylinder; 912, Return spring; 913, round rod; 914, sleeve plate; 915, slide rod; 92, arc block; 93, arc strip; 931, through rod; 932, third spring; 933, docking seat; 9331, conical groove; 94, connecting rod; 95, insert strip; 951, conical protrusion; 10, transverse ring; 11, circulation connecting pipe; 111, arc groove; 112, through hole; 12, lightweight ball; 121, steel housing; 122, lightweight metal ball; 13, ball channel. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments 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.

[0042] See also Figures 1 to 8 The present invention provides an external circulation ball screw, and the technical solution is as follows:

[0043] Reference Figure 1 and Figure 2 , Figure 2 In order to facilitate the viewing of the lightweight ball 12 and the ball channel 13, the lightweight ball 12 is only shown in the ball channel 13 on one side. In a normal state, the lightweight balls 12 are connected to each other and distributed in the ball channel 13. An external circulation ball screw comprises a screw 1, a threaded groove 2, a dustproof sealing disk 3, and an external nut housing 4. The threaded groove 2 is opened on the outer periphery of the screw 1, the dustproof sealing disk 3 is sleeved on the outer periphery of the screw 1, the external nut housing 4 is located on the outside of the screw 1, and the dustproof sealing disk 3 is located at the end of the external nut housing 4. It also includes a circulation pipe 5, a ball control box 6, a top seat 7, a channel interception component 8, and a ball limit group Parts 9, traverse ring 10, circulation connecting tube 11 and light ball 12, circulation tube 5 is installed on external nut housing 4, and the inside of circulation tube 5 is communicated with thread groove 2, light ball 12 located in thread groove 2 on the inner side of external nut housing 4 can enter circulation tube 5, ball control box 6 is installed between ends of circulation tube 5, channel interception assembly 8 is installed inside ball control box 6, circulation connecting tube 11 is installed inside ball control box 6, and ball channel 13 is formed between the inside of circulation connecting tube 11 and circulation tube 5, light ball 12 in circulation tube 5 can pass through ball channel 13 and continue along thread groove 2 The ball limit assembly 9 is installed between one end inside the ball control box 6 and the circulation connection pipe 11 near the end. The ball limit assembly 9 is divided into two groups, which are respectively located on both sides of the channel interception assembly 8. The transverse ring 10 is installed at the end of the ball limit assembly 9, and the outer periphery of the transverse ring 10 is in contact with the channel interception assembly 8. The end of the transverse ring 10 is in contact with the end of the circulation connection pipe 11. During the continuous movement of the lightweight ball 12, it can smoothly pass through the inner periphery of the transverse ring 10. The lightweight ball 12 is set in the ball channel 13 and the inner thread groove 2 of the external nut housing 4. When the screw rod 1 drives the equipment to stop, the channel interception assembly 8 moves up. The screw rod 1 driving device and the channel interception component 8 are both connected to the synchronization switch. When the synchronization switch connects the power of the screw rod 1 driving device, the power of the channel interception component 8 is disconnected, and when the power of the channel interception component 8 is connected, the power of the screw rod 1 driving device is disconnected; when the power of the screw rod 1 driving device is disconnected, the power of the channel interception component 8 is connected, thereby starting the channel interception component 8. After the channel interception component 8 is started, it pushes the transverse ring 10 to move horizontally. The horizontal balance of the transverse ring 10 easily squeezes the ball limit assembly 9, so that the ball limit assembly 9 starts immediately. When the ball limit assembly 9 is squeezed by the transverse ring 10, it limits the movement of the lightweight ball 12.

[0044] As an embodiment of the present invention, refer to Figure 2 , Figure 3 and Figure 5The channel interception component 8 includes a limit column 81, a lifting seat 82, an electromagnet 84 and a magnetic shielding plate 85. The magnetic shielding plate 85 is installed on the surface of the top seat 7. The magnetic shielding plate 85 is located on the surface of the top seat 7 to avoid the influence of magnetic force on the metal spray containing iron, cobalt, nickel and the like ejected by the nozzle of the 3D printing device. The electromagnet 84 is fitted on the bottom of the magnetic shielding plate 85. The limit column 81 is installed between the bottom of the electromagnet 84 and the ball control box 6. The lifting seat 82 is arranged inside the ball control box 6, and the limit column 81 passes through the lifting seat 82. The limit column 81 limits the moving trajectory of the lifting seat 82 so that the lifting seat 82 moves in the vertical direction. , and no rotation will occur. The two ends of the lifting seat 82 are respectively fitted with the two transverse rings 10. When the power of the electromagnet 84 is turned on, the lifting seat 82 moves up along the limit column 81, and the contact area between the lifting seat 82 and the transverse ring 10 is reduced, so that the transverse ring 10 moves horizontally along the inner wall of the ball control box 6. After the power of the electromagnet 84 is turned on, the lifting seat 82 is attracted to move upward by magnetic force. When the lifting seat 82 moves upward, the lifting seat 82 will push the transverse ring 10 to both sides, so that the transverse ring 10 fits the inner wall of the ball control box 6 and moves horizontally in a straight line. When the transverse ring 10 moves horizontally, it presses the ball limit assembly 9 and starts the ball limit assembly 9 synchronously.

[0045] As an embodiment of the present invention, refer to Figure 2 , Figure 3 and Figure 5The ball limit assembly 9 includes a limit rod 91, an arc strip 93, a connecting rod 94 and an insert strip 95. The limit rod 91 is installed at one end inside the ball control box 6. The arc strip 93 is arranged side by side in the corresponding circulation connection pipe 11, and the inner circumference of the circulation connection pipe 11 is provided with an arc groove 111 adapted to the arc strip 93. A through hole 112 with an isosceles trapezoidal cross section in top view is provided in the arc groove 111. The depth of the arc groove 111 is greater than the thickness of the arc strip 93. The side wall of the arc strip 93 is connected with a through rod 931 that penetrates the through hole 112. The through rod 931 is located outside the circulation connection pipe 11. A docking seat 933 is installed at one end, and a conical groove 9331 is opened on the side wall of the docking seat 933. The docking seat 933 is set to a hemispherical surface on the side close to the circulation connection pipe 11. After the docking seat 933 loses the limiting effect of the limit rod 91, the docking seat 933 can be fitted to the outer periphery of the circulation connection pipe 11 and swing horizontally. The through rod 931 swings horizontally in the through hole 112. The outer periphery of the through rod 931 is sleeved with a third spring 932 located in the arc groove 111. The third spring 932 is supported between the arc strip 93 and the circulation connection pipe 11 to prevent the arc from being lost after the docking seat 933 loses the limitation of the limit rod 91. The strip 93 swings freely in the arc groove 111; the connecting rod 94 is installed at the end of the limit rod 91 close to the transverse ring 10, and the insertion strip 95 is installed at the end of the connecting rod 94, and the side wall of the insertion strip 95 is provided with a conical protrusion 951 set at the same height as the conical groove 9331; in the static state, the conical protrusion 951 on the side wall of the insertion strip 95 extends into the conical groove 9331 of the docking seat 933, and the arc strip 93 cannot deflect to one side at this time; when the transverse ring 10 moves horizontally to squeeze the limit rod 91, the limit rod 91 drives the insertion strip 95 to move toward the end of the ball control box 6 through the connecting rod 94, and the conical protrusion 951 on the side wall of the insertion strip 95 The protrusion 951 is separated from the conical groove 9331 of the docking seat 933. At this time, the arc strip 93 together with the through rod 931 can swing horizontally along the through hole 112, so that after the arc strip 93 rotates a certain angle, it fits the outer periphery of the lightweight ball 12 in the ball channel 13. The rotated arc strip 93 can intercept the lightweight ball 12 at the rear, thereby assisting in limiting the lightweight ball 12; when the power supply of the channel interception component 8 is disconnected, under the action of the limiting rod 91, the transverse ring 10 can be pushed in the reverse direction, so that after the channel interception component 8 moves down and resets, the transverse ring 10 continues to fit the side wall of the lifting seat 82.

[0046] As an embodiment of the present invention, refer to Figure 5 and Figure 6The lifting seat 82 includes a box body 821, an iron block 822, a first spring 823 and a side plate 824. The iron block 822 is arranged inside the box body 821, the first spring 823 is sleeved on the outer periphery of the limiting column 81, and the first spring 823 is abutted between the top of the iron block 822 and the box body 821, and the side plate 824 is installed on the side wall of the box body 821. The box body 821 is made of lightweight and high-strength polycarbonate, which has a lower density than general metal materials and has better impact resistance. After the power of the electromagnet 84 is turned on, the iron block 822 is attracted to move up under the magnetic force of the electromagnet 84. When the iron block 822 moves to the highest point, the first spring 823 is in a compressed state. When the magnetic force is lost, the compressed first spring 823 quickly resets, and the iron block 822 quickly moves down under the elastic force of the first spring 823 and its own gravity, and drives the lifting seat 82 to move to the lowest point, losing the pushing effect on the transverse moving ring 10.

[0047] As an embodiment of the present invention, refer to Figure 6 Both ends of the box body 821 are constructed with arc surfaces 8211, and the radius of the arc surface 8211 is equal to the outer radius of the transverse ring 10. In a static state, both ends of the box body 821 are in contact with the corresponding transverse ring 10, and when the lightweight ball 12 quickly passes through the inner side of the transverse ring 10, the transverse ring 10 is prevented from shaking.

[0048] As an embodiment of the present invention, refer to Figure 5 A second spring 83 is sleeved on the outer periphery of the limiting column 81, and the second spring 83 abuts between the bottom of the electromagnet 84 and the top of the lifting seat 82. When the lifting seat 82 moves up, it will squeeze the second spring 83. After the magnetic force is lost, the elastic force of the second spring 83 can accelerate the reset of the lifting seat 82.

[0049] As an embodiment of the present invention, refer to Figure 2 The ball limit assembly 9 also includes an arc block 92, which is symmetrically installed on the top and bottom surfaces inside the ball control box 6. The surface of the arc block 92 is provided with an arc surface adapted to the outer periphery of the transverse ring 10. The arc block 92 limits the horizontal movement distance of the transverse ring 10 to exceed the diameter of the transverse ring 10, thereby preventing the transverse ring 10 from excessively displacing and causing the lightweight balls 12 to move between the circulating connecting pipes 11 through the gaps at the transverse ring 10.

[0050] As an embodiment of the present invention, refer to Figure 7The limiting rod 91 includes a cylinder 911, a return spring 912, a sleeve plate 914 and a slide rod 915. The return spring 912 is arranged in the cylinder 911, the sleeve plate 914 is arranged inside the cylinder 911, and the side wall of the sleeve plate 914 abuts against the end of the return spring 912. The slide rod 915 is installed on the side wall of the sleeve plate 914, and the slide rod 915 extends to the outside of the cylinder 911. The inner circumference of the cylinder 911 is installed with a round rod 913 located inside the return spring 912, and the inner circumference of the slide rod 915 is configured with a round rod 913 adapted to the round rod 913. Column groove, when the transverse moving ring 10 produces horizontal displacement under the action of the channel interception assembly 8, the transverse moving ring 10 drives the sliding rod 915 to move, and the sliding rod 915 moves toward the inside of the cylinder 911, and the sleeve plate 914 applies pressure to the reset spring 912. When the transverse moving ring 10 is reset, the sleeve plate 914 can be pushed under the action of the reset spring 912 to assist in quickly resetting the transverse moving ring 10; in the static state, the limit rod 91 can support the transverse moving ring 10 from the side of the transverse moving ring 10 away from the channel interception assembly 8 to ensure the stability of the transverse moving ring 10 in the static state.

[0051] As an embodiment of the present invention, refer to Figure 7 The lightweight ball 12 includes a steel shell 121 and a lightweight metal ball 122. The steel shell 121 is wrapped and attached to the outer periphery of the lightweight metal ball 122. During manufacturing, the lightweight metal ball 122 made of titanium metal on the inside is first manufactured, and then the steel shell 121 is cast on the outer periphery of the lightweight metal ball 122.

[0052] Working principle: When the 3D printing device is in normal working state, the screw 1 rotates at a constant speed under the action of the driving device. At this time, the lightweight ball 12 on the inner side of the external nut housing 4 moves along the thread groove 2, continuously passing through the circulation pipe 5, the inner side of the traverse ring 10 and the circulation connecting pipe 11, so that the external nut housing 4 moves horizontally;

[0053] When the 3D printing device moves with the external nut shell 4 and needs to be stopped, in order to prevent the lightweight ball 12 from continuing to move under the action of inertia, the traverse ring 10 and the ball channel 13 are misaligned to prevent the nozzle of the 3D printing device from continuing to move with the external nut shell 4 under the action of inertia of the lightweight ball 12, so as to avoid printing errors caused by the nozzle not being in the recorded stop position when the 3D printing device is started later; at this time, the synchronous switch disconnects the power supply of the driving device of the screw rod 1, and at the same time disconnects the channel interception component 8 When the power is turned on and the channel interception assembly 8 is powered on, the electromagnet 84 instantly generates sufficient magnetic force to attract the iron block 822 to move upward together with the box body 821. When the box body 821 moves upward, it squeezes and pushes the transverse ring 10 toward the inner end of the ball control box 6. The transverse ring 10 moves horizontally along the upper and lower surfaces of the inner side of the ball control box 6. When the transverse ring 10 is displaced, it is misaligned with the ball channel 13. The subsequent lightweight balls 12 are blocked by the transverse ring 10 and cannot continue to move, thereby preventing the lightweight balls 12 from continuing to move due to inertia.

[0054] When the transverse ring 10 is displaced, in order to further enhance the limiting effect on the lightweight ball 12 and reduce the impact effect of the lightweight ball 12 on the transverse ring 10; when the transverse ring 10 is displaced, it drives the sliding rod 915 and the connecting rod 94 to move horizontally together, so that the inserting strip 95 is separated from the docking seat 933. After losing the restriction of the inserting strip 95, the lightweight ball 12 squeezes the arc strip 93, and the through rod 931 swings horizontally in the through hole 112, thereby driving the docking seat 933 and the arc strip 93 in the arc groove 111 to adapt to the displacement of the lightweight ball 12 and swing to one side. After the arc strip 93 swings, it fits the outer periphery of the lightweight ball 12, and the arc strip 93 deviates from the ball channel 13, and intercepts the subsequent lightweight ball 12, turning the lightweight ball 12 into a stationary state;

[0055] When the subsequent 3D printing device needs to be restarted, it is necessary to disconnect the power supply of the channel interception component 8 and connect the power supply of the screw rod 1 driving device to reset the transverse ring 10, so that the lightweight ball 12 can move in the ball channel 13 through the inner circumference of the transverse ring 10; the synchronous switch connects the power supply of the driving device of the screw rod 1 and disconnects the power supply of the channel interception component 8 at the same time. When the power supply of the channel interception component 8 is disconnected, the lifting seat 82 loses the magnetic attraction of the electromagnet 84 and moves downward, and the transverse ring 10 and the side of the box 821 are The wall contact area gradually increases. During this process, after the limit rod 91 loses the extrusion of the transverse ring 10, the sleeve plate 914 and the slide rod 915 extend horizontally under the action of the reset spring 912, and slowly push the transverse ring 10 toward the side of the box body 821, so that the transverse ring 10 slowly returns to between the two corresponding ends of the circulation connecting pipes 11, and the inner periphery of the transverse ring 10 is connected with the ball channel 13. When the screw rod 1 rotates under the action of the driving device, the lightweight balls 12 can continue to circulate along the ball channel 13 and the inner periphery of the transverse ring 10.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An external circulation ball screw, comprising a screw (1), a thread groove (2), a dustproof sealing disk (3), and an external nut housing (4), characterized in that: It also includes a circulation pipe (5), a ball control box (6), a top seat (7), a channel interception assembly (8), a ball stop assembly (9), a transverse ring (10), a circulation connection pipe (11) and a lightweight ball (12), wherein the circulation pipe (5) is mounted on the external nut housing (4), and the interior of the circulation pipe (5) is connected to the threaded groove (2), the ball control box (6) is mounted between the ends of the circulation pipe (5), the channel interception assembly (8) is mounted inside the ball control box (6), a circulation connection pipe (11) is mounted inside the ball control box (6), and a ball channel (13) is formed between the interior of the circulation connection pipe (11) and the circulation pipe (5), and the ball stop assembly (9) is mounted on the top seat (7), and a ball stop assembly (10) is mounted on the top seat (7), and a circulation connection pipe (11) is mounted on the top seat (7), and a ball stop assembly (9) is mounted on the bottom seat (7), and a ball stop assembly (10) is mounted on the bottom seat (7), and a ball stop assembly (11) is mounted on the top seat (7), and a ball stop assembly (11) is mounted on the top seat (7), and a ball stop assembly (13) is formed between the interior of the circulation connection pipe (11) and the circulation pipe (5). The assembly (9) is installed between one end inside the ball control box (6) and a circulation connection pipe (11) near the end, the transverse ring (10) is installed at the end of the ball limit assembly (9), and the outer periphery of the transverse ring (10) is in contact with the channel interception assembly (8), the end of the transverse ring (10) is in contact with the end of the circulation connection pipe (11), the lightweight ball (12) is arranged in the ball channel (13) and the inner thread groove (2) of the external nut housing (4), when the screw rod (1) drives the device to stop, the channel interception assembly (8) moves upward, and pushes the transverse ring (10) to move horizontally, and the ball limit assembly (9) is squeezed by the transverse ring (10) to limit the movement of the lightweight ball (12).

2. The external circulation ball screw according to claim 1, characterized in that: The channel interception component (8) includes a limit column (81), a lifting seat (82), an electromagnet (84) and a magnetic shielding plate (85), wherein the magnetic shielding plate (85) is installed on the surface of the top seat (7), the electromagnet (84) is installed in a close fit on the bottom of the magnetic shielding plate (85), the limit column (81) is installed between the bottom of the electromagnet (84) and the ball control box (6), the lifting seat (82) is arranged inside the ball control box (6), and the limit column (81) passes through the lifting seat (82), and the two ends of the lifting seat (82) are respectively in close fit with two transverse rings (10), and when the electromagnet (84) is powered on, the lifting seat (82) moves up along the limit column (81) and pushes the transverse rings (10) to both sides.

3. The external circulation ball screw according to claim 2, characterized in that: The ball limiting assembly (9) comprises a limiting rod (91), an arc strip (93), a connecting rod (94) and an inserting strip (95); the limiting rod (91) is mounted at one end inside the ball control box (6); the arc strip (93) is arranged side by side in a corresponding circulation connecting pipe (11); an arc groove (111) adapted to the arc strip (93) is provided on the inner circumference of the circulation connecting pipe (11); a through hole (112) having an isosceles trapezoidal cross section in top view is provided in the arc groove (111); a through hole (112) penetrating through the through hole (112) is connected to the side wall of the arc strip (93); The through rod (931) is provided with a docking seat (933) at one end of the through rod (931) located outside the circulation connection pipe (11), a conical groove (9331) is provided on the side wall of the docking seat (933), a third spring (932) located in the arc groove (111) is sleeved on the outer periphery of the through rod (931), the connecting rod (94) is installed at one end of the limit rod (91) close to the transverse ring (10), the inserting strip (95) is installed at the end of the connecting rod (94), and a conical protrusion (951) arranged at the same height as the conical groove (9331) is provided on the side wall of the inserting strip (95).

4. The external circulation ball screw according to claim 3, characterized in that: The lifting seat (82) comprises a box body (821), an iron block (822), a first spring (823) and a side plate (824); the iron block (822) is arranged inside the box body (821); the first spring (823) is sleeved on the outer periphery of the limiting column (81), and the first spring (823) is abutted between the top of the iron block (822) and the box body (821); and the side plate (824) is installed on the side wall of the box body (821).

5. The external circulation ball screw according to claim 4, characterized in that: Both ends of the box body (821) are constructed with arcuate surfaces (8211), and the radius of the arcuate surface (8211) is equal to the radius of the outer circumference of the transverse ring (10).

6. The external circulation ball screw according to claim 5, characterized in that: A second spring (83) is sleeved on the outer periphery of the limiting column (81), and the second spring (83) abuts between the bottom of the electromagnet (84) and the top of the lifting seat (82).

7. The external circulation ball screw according to claim 6, characterized in that: The ball limit assembly (9) also includes an arc block (92), which is symmetrically installed on the top and bottom surfaces inside the ball control box (6), and the surface of the arc block (92) is provided with an arc surface that is compatible with the outer periphery of the transverse ring (10).

8. The external circulation ball screw according to claim 3, characterized in that: The limiting rod (91) comprises a cylinder (911), a return spring (912), a sleeve plate (914) and a slide rod (915); the return spring (912) is arranged in the cylinder (911); the sleeve plate (914) is arranged inside the cylinder (911), and the side wall of the sleeve plate (914) abuts against the end of the return spring (912); the slide rod (915) is installed on the side wall of the sleeve plate (914), and the slide rod (915) extends to the outside of the cylinder (911).

9. The external circulation ball screw according to claim 8, characterized in that: A round rod (913) located inside the return spring (912) is installed on the inner circumference of the cylinder (911), and a cylindrical groove adapted to the round rod (913) is constructed on the inner circumference of the slide rod (915).

10. The external circulation ball screw according to claim 9, characterized in that: The lightweight ball (12) comprises a steel shell (121) and a lightweight metal ball (122), wherein the steel shell (121) is wrapped and attached to the outer circumference of the lightweight metal ball (122).

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