An external thread rolling device and its thread rolling method

Abstract

An external thread rolling device and its thread rolling method. By setting a first conical surface on the rolling die housing and a matching smooth inclined curved surface on the inner surface of the expanding wheel ring, the external thread rolling device can smoothly expand the tool after the rolling process is completed. At the same time, by adjusting the front-back position and / or rotation angle of the expanding wheel ring relative to the rolling die head frame body, the radial position of the rolling die housing to the axis of the frame body is adjusted, so that the rolling die housing and the rolling die wheels generate radial movement simultaneously, and thus can meet the thread rolling processing requirements of workpieces with different diameters, such as steel bars.

Description

Technical Field

[0001] The present invention belongs to the technical field of external thread rolling equipment, and particularly relates to an external thread rolling equipment with high working efficiency, simple structure and capable of processing workpieces with different diameters, and its thread rolling method. Background Art

[0002] At present, the external thread rolling device can only process workpieces with one outer diameter. When the pitch is the same, to process the external threads of workpieces with different outer diameters, the rolling dies need to be replaced. Therefore, a set of rolling devices needs to be equipped with multiple sets of rolling heads, which greatly increases the device cost. And after the processing is completed, the rolling head needs to be rotated in the reverse direction to withdraw the processed workpiece, wasting processing time and reducing processing efficiency. Summary of the Invention

[0003] The present invention provides an external thread rolling equipment and its thread rolling method. By setting a first conical surface on the rolling die housing and a matching smooth inclined curved surface on the inner surface of the expanding wheel ring, the external thread rolling equipment can smoothly expand the tool after the rolling process. At the same time, by adjusting the front-back position and / or rotation angle of the expanding wheel ring relative to the headstock of the rolling die, the radial position of the rolling die housing to the axis of the frame is adjusted, so that the rolling die housing and the rolling dies move radially at the same time, thereby meeting the rolling processing requirements of workpieces with different diameters such as steel bars.

[0004] The technical solution of the present invention is as follows: An external thread rolling equipment includes

[0005] A rolling die head, which is driven to rotate by a motor; includes a cylindrical frame, a rolling die device and an expanding wheel device;

[0006] The rolling dies of the rolling die device are arranged on the frame through a rolling die housing. A first compression spring is arranged between the rolling die housing and the frame. A first conical surface is arranged on the outer side of the rolling die housing, and the side with a larger diameter of the first conical surface faces forward;

[0007] An expanding wheel device, which is sleeved on the outer sides of the rolling die housing and the frame, and realizes the expanding and retracting operations of the rolling dies by moving back and forth along the frame, including an expanding wheel ring and an elastic limiting component; a smooth inclined curved surface corresponding to the first conical surface is arranged on the inner surface of the expanding wheel ring, and the conical slope of the smooth inclined curved surface in the axial direction is equal to the conical slope of the first conical surface;

[0008] Through the elastic limiting component, the expanding wheel ring realizes axially adjustable positioning on the frame;

[0009] A hydraulic feeding device, whose moving end is provided with a moving platform for driving the rolling die head and the motor to move back and forth;

[0010] Fixed frame for carrying the fixed end of the hydraulic feeding device.

[0011] Preferably, a plurality of the smooth inclined surfaces are rotationally symmetrically arranged on the inner surface of the expanding wheel ring, and the number of the smooth inclined surfaces is the same as the number of the thread rolling wheel assemblies or an integer multiple of the number of the thread rolling wheel assemblies; and in any radial section of the expanding wheel ring, the distance from the smooth inclined surface to the axis of the expanding wheel ring gradually decreases along its circumferential direction.

[0012] Preferably, the expanding wheel device further includes an expanding wheel sliding sleeve fixed to the rear end of the expanding wheel ring or the expanding wheel ring extends rearward to form an expanding wheel sliding sleeve. A plurality of radial holes are rotationally symmetrically arranged on the side wall of the expanding wheel sliding sleeve. One end of the elastic limiting component is fixed to the radial hole, and the other end is an elastically pre-pressed end; correspondingly, a pre-pressing groove group for clamping the elastically pre-pressed end is arranged on the frame body.

[0013] Preferably, a second conical surface with a conical slope greater than that of the first conical surface is further arranged on the outer side surface of the thread rolling housing, and the larger diameter side of the second conical surface is smoothly butted with the smaller diameter side of the first conical surface through an arc.

[0014] Preferably, the conical slope range of the first conical surface is 6° - 8°.

[0015] Preferably, the conical slope of the first conical surface is 7°.

[0016] Preferably, each pre-pressing groove in the pre-pressing groove group is a conical pre-pressing groove or an arc-shaped pre-pressing groove.

[0017] Preferably, the expanding wheel sliding sleeve and the expanding wheel ring are fixed together by fastening bolts. A plurality of indexing annular holes are rotationally symmetrically arranged on the expanding wheel sliding sleeve, and a plurality of bolt holes are arranged on the corresponding expanding wheel ring. The fastening bolts pass through the indexing annular holes and are fastened in the bolt holes.

[0018] Preferably, the elastic limiting component includes a first elastically pre-pressed pin, an adjusting nut, and a second compression spring sleeved on the first elastically pre-pressed pin. One end of the first elastically pre-pressed pin is fixed to the adjusting nut, and the other end is the elastically free end. The second compression spring is located between the adjusting nut and the upper boss of the elastically free end, and the lower end surface of the elastically free end is arc-shaped.

[0019] Preferably, the adjusting nut is screwed on the expanding wheel sliding sleeve.

[0020] Preferably, the expanding wheel device further includes a rear spring pressing ring and an elastic preloading assembly. The elastic preloading assembly includes a second elastic preloading pin and a third compression spring sleeved on the second elastic preloading pin. One end of the second elastic preloading pin is fixed to the rear spring pressing ring, and the other end is slidably connected to an axial pin hole provided on the front end face of the expanding wheel ring.

[0021] Preferably, the expanding wheel ring includes an elastic preloading pin fixing portion and a rear spring pressing ring sliding portion arranged in front of the expanding wheel sleeve in sequence. The outer diameter of the elastic preloading pin fixing portion is larger than that of the rear spring pressing ring sliding portion. A plurality of elastic preloading pin sliding holes are provided on the front end face of the elastic preloading pin fixing portion. A plurality of first positioning protrusions extend outward from the axis at the front end of the rear spring pressing ring sliding portion.

[0022] Preferably, along the axial direction of the frame body, a plurality of the preloading groove groups are provided. When all the preloading grooves in the plurality of preloading groove groups are mapped to the same radial section of the frame body, they cannot be superimposed.

[0023] Preferably, it further includes a rib stripping device and a tool expanding device. The tool expanding device includes a tool expanding sleeve and a tool expanding ring provided at the front end of the tool expanding sleeve. The rib stripping device includes a plurality of rib stripping knives provided on the frame body. A fourth compression spring compressed along the radial direction of the frame body is provided between the rib stripping knife and the frame body. A plurality of smooth curved surfaces are rotationally symmetrically provided on the inner surface of the tool expanding ring corresponding to the rib stripping knife. On any cross section of the tool expanding ring, the distance from the smooth curved surface to the axis of the expanding wheel ring gradually decreases along the circumferential direction thereof, so that the distance from the rib stripping knife to the axis of the expanding wheel ring gradually decreases.

[0024] Preferably, the tool expanding device further includes a tool expanding positioning end cover provided at the front side of the tool expanding ring.

[0025] Preferably, the frame body is connected to the motor through a flange. The outer diameter of the side of the flange connected to the frame body is equal to the outer diameter of the frame body. A second positioning protrusion extends outward from the axis at the side of the flange connected to the motor.

[0026] Preferably, the external thread rolling equipment further includes a tool retracting device, a tool expanding collision wheel device and a stroke adjusting rod. The stroke adjusting rod is fixed on the moving platform of the hydraulic feeding device. A trapezoidal groove and a stop block provided in front of the trapezoidal groove are provided on the stroke adjusting rod. The tool retracting device includes a tool retracting support provided on the machine frame. A tool retracting assembly and a wheel retracting assembly are provided on the tool retracting support.

[0027] Preferably, the tool retraction assembly includes a tool retraction contact wheel, a third elastic preloading pin, a tool retraction adjustment shaft, and a tool retraction adjustment wheel. A fifth compression spring is provided between the third elastic preloading pin and the tool retraction support; the third elastic preloading pin is perpendicular to the tool retraction adjustment shaft, and the tool retraction adjustment wheel is installed on the tool retraction adjustment shaft; during tool retraction, the tool retraction adjustment wheel is located within the trapezoidal groove, such that the fifth compression spring is in a relaxed state, and the first tool retraction contact wheel is in an internal position relative to the tool retraction support; during feeding, the tool retraction adjustment wheel rolls out of the trapezoidal groove, and then the outer side surface of the stroke adjustment rod causes the fifth compression spring to be in a compressed state, and the tool retraction contact wheel is in an external position relative to the tool retraction support.

[0028] Preferably, the tool expansion contact wheel device includes a tool expansion contact wheel, a fourth elastic preloading pin, and a tool expansion support. A sixth compression spring is provided between the fourth elastic preloading pin and the tool expansion support. One end of the fourth elastic preloading pin is provided with the tool expansion contact wheel, and the other end extends outward through the tool expansion support with a pressing shaft 221; during rib stripping and feeding, the block presses the preloading pin inward, the sixth compression spring is in a compressed state, and the tool expansion contact wheel is in an internal position relative to the tool expansion support, such that the tool expansion device contacts the tool expansion contact wheel; when the tool expansion is completed, the stroke adjustment rod advances just enough to disengage the preloading pin from the block, and the sixth compression spring returns to a relaxed state, causing the preloading pin and the tool expansion contact wheel to return to an external position.

[0029] Preferably, the outer diameter of the rear elastic pressing ring is greater than the maximum outer diameter of the tool expansion device, and the tool expansion contact wheel can still touch the rear elastic pressing ring in the external position.

[0030] A method for thread rolling using the above external thread rolling equipment includes the following steps:

[0031] S1. Obtain the diameter R of the workpiece to be processed. By adjusting the position and / or rotation angle of the expansion wheel ring relative to the frame body, change the contact position between the first conical surface and the smooth inclined curved surface, so that the thread rolling wheel assembly moves radially, such that the radial distance between the thread rolling wheels is just enough to process a workpiece with a diameter of R.

[0032] S2. Clamp the workpiece with a vise. The thread rolling head rotates forward under the drive of a motor and simultaneously advances along the axial direction of the workpiece under the drive of a hydraulic feeding device; when the rib stripping tool touches the workpiece, rib stripping starts, and rib stripping is completed until the tool expansion device touches the tool expansion contact wheel; at the same time, since the thread rolling head continues to feed, the backward pressing force generated by the tool expansion contact wheel on the tool expansion device, when this pressing force is greater than the pre-tightening force of the tool expansion sliding sleeve, the tool expansion device rebounds backward, and the rib stripping tool expands radially and separates from the workpiece to complete tool expansion.

[0033] S3. The thread rolling head continues to feed for thread rolling. When the expanding wheel device touches the tool expanding wheel and continues to feed, when the second compression spring is compressed to the limit position, the thread rolling is completed. At the same time, due to the continuous feeding of the thread rolling head, the backward pressing force generated by the tool expanding wheel on the expanding wheel device, when this pressing force is greater than the pre-tightening force of the expanding wheel sliding sleeve, the expanding wheel device rebounds quickly, and the thread rolling wheel assembly expands radially, separating the workpiece from the thread rolling wheel to complete the expanding of the wheel.

[0034] S4. Stop feeding and quickly move backward. The tool retracting device quickly resets the expanding wheel device and the tool expanding device to the tool retracting position, and takes out the workpiece from the vise.

[0035] The advantages of the present invention over the prior art are as follows:

[0036] 1. In the external thread rolling equipment and its thread rolling method of the present invention, the outer side of the thread rolling housing is provided with a first conical surface, and the inner surface of the expanding wheel ring corresponding to the first conical surface is provided with a smooth inclined curved surface, and the taper of the smooth inclined curved surface in the axial direction is equal to the taper of the first conical surface. Through the cooperation of the first conical surface and the smooth inclined curved surface, the external thread rolling equipment can smoothly expand the tool after the rolling process is completed. At the same time, by adjusting the front and rear positions of the expanding wheel ring relative to the thread rolling head, and further adjusting the radial position of the thread rolling housing to the axis of the frame, that is, the free end of the elastic limiting component can be used to clamp the expanding wheel into the conical pre-pressing grooves at different axial positions of the frame, so that the thread rolling housing and the thread rolling wheel move radially at the same time, and thus can meet the thread rolling processing requirements of workpieces with different diameters such as steel bars.

[0037] 2. In the external thread rolling equipment and its thread rolling method of the present invention, the inner surface of the expanding wheel ring is rotationally symmetrically provided with a plurality of smooth inclined curved surfaces, and the number of the smooth inclined curved surfaces is the same as the number of the thread rolling wheel assemblies or the number of the smooth inclined curved surfaces is an integer multiple of the number of the thread rolling wheel assemblies. On any cross-section of the expanding wheel ring, the distance from the smooth inclined curved surface to the axis of the expanding wheel ring gradually decreases along the circumferential direction. By rotating the expanding wheel ring, the smooth inclined curved surface forces the first conical surface to move radially, and thus can further change the rolling diameter, so that a set of thread rolling heads can process the external threads of workpieces with a larger outer diameter range such as steel bars.

[0038] 3. For the external thread rolling equipment and its thread rolling method of the present invention, by arranging a second conical surface with a larger conical slope behind the first conical surface, and making a smooth arc transition between the first conical surface and the second conical surface, when the expanding wheel, the backward movement of the expanding wheel ring is smoother. Among them, the theoretical mechanical self-locking angle of steel is generally 8.5°. Therefore, in order to make the expanding wheel ring generate a certain mechanical self-locking during thread rolling processing, reduce the design difficulty of the elastic limiting component, and at the same time be able to expand the wheel smoothly when expanding the wheel, the conical slope of the first conical surface is preferably 6° - 8°, and further preferably 7°.

[0039] 4. For the external thread rolling equipment and its thread rolling method of the present invention, since the expanding wheel ring needs to be adjusted forward and backward and / or the rotation angle adjusted to accurately position to the position corresponding to the diameter of the workpiece to be processed, and at the same time needs to be able to move backward smoothly when expanding the wheel to achieve wheel expansion. Therefore, a sliding sleeve for the expanding wheel is designed at the rear end of the expanding wheel ring, and a graduated annular hole is designed on the sliding sleeve for the expanding wheel, which can realize the continuous rotational positioning of the expanding wheel ring, and thus realize the rolling of threads with non-standard steel bar diameters.

[0040] 5. For the external thread rolling equipment and its thread rolling method of the present invention, the expanding wheel device further includes a rear spring pressing ring and a second elastic pre-pressing pin. One end of the second elastic pre-pressing pin is fixed to the rear spring pressing ring, and the other end is fixed to the expanding wheel ring. When expanding the wheel, the compression spring of the second elastic pre-pressing pin is rapidly released, and thus the expanding wheel ring can rapidly spring backward relative to the rear spring pressing ring.

[0041] 6. For the external thread rolling equipment and its thread rolling method of the present invention, by designing a plurality of elastic limiting components, the device uses a compression spring to make the first elastic pre-pressing pin flexibly cooperate with the conical pre-pressing groove on the frame body, so as to prevent the expanding wheel ring from slipping due to vibration during the rib peeling process. The upper end of the first elastic pre-pressing pin is fixed to the sliding sleeve for the expanding wheel through an adjusting nut, and it is also convenient to adjust the locking force of the elastic limiting component by rotating the adjusting nut to adjust the depth of the adjusting nut screwed onto the sliding sleeve for the expanding wheel.

[0042] 7. For the external thread rolling equipment and its thread rolling method of the present invention, by arranging a trapezoidal groove and a stop block on the stroke adjusting rod, and cooperating with the tool retracting device and the tool expanding and wheel expanding collision device, automatic tool retraction, automatic tool expansion and automatic wheel expansion are realized, with a simple structure, flexible cooperation and high reliability. Description of the Drawings

[0043] Figure 1 is the top view structural schematic diagram of the external thread rolling equipment and its thread rolling method of the present invention;

[0044] Figure 2 is the front view sectional structural schematic diagram of the external thread rolling equipment and its thread rolling method of the present invention;

[0045] Figure 3 It is a three-dimensional structure schematic diagram of the thread rolling wheel assembly of the external thread rolling equipment and its thread rolling method described in the present invention;

[0046] Figure 4 It is a partial sectional structure schematic diagram of the elastic limit component of the external thread rolling equipment and its thread rolling method described in the present invention;

[0047] Figure 5 It is a radial sectional schematic diagram of the thread rolling head of the external thread rolling equipment and its thread rolling method described in the present invention;

[0048] Figure 6 It is a three-dimensional mating structure schematic diagram of the stroke adjustment rod, the tool expanding collision wheel device and the tool retracting device of the external thread rolling equipment and its thread rolling method described in the present invention.

[0049] The reference numerals in the figure are as follows:

[0050] 1 - Thread rolling head, 11 - Frame body, 111 - Conical pre-pressing groove, 12 - Rib stripping device, 121 - Rib stripping tool, 13 - Tool expanding device, 131 - Tool expanding end cover, 132 - Tool expanding ring, 133 - Tool expanding sliding sleeve,

[0051] 14 - Thread rolling device, 141 - Thread rolling wheel assembly, 1411 - Thread rolling outer shell, 1412 - Thread rolling wheel, A - First conical surface, B - Second conical surface,

[0052] 15 - Wheel expanding device, 151 - Wheel expanding ring, C - Smooth inclined curved surface, 1511 - Elastic pre-pressing pin fixing part, 1512 - Rear elastic pressing ring sliding part, 15121 - First positioning protrusion, 152 - Elastic limit component, 1521 - First elastic pre-pressing pin, 15211 - Elastic pre-pressing end, 1522 - Adjusting nut, 1523 - Second compression spring, 153 - Wheel expanding sliding sleeve, 1531 - Indexing annular hole, 154 - Rear elastic pressing ring, 155 - Elastic pre-pressing assembly, 1551 - Second elastic pre-pressing pin, 1552 - Third compression spring,

[0053] 2 - Tool expanding collision wheel device, 21 - Tool expanding collision wheel, 22 - Fourth elastic pre-pressing pin, 221 - Pressing shaft, 23 - Tool expanding support,

[0054] 3 - Tool retracting device, 31 - Tool retracting support, 32 - Tool retracting assembly, 321 - Tool retracting collision wheel, 323 - Tool retracting adjustment shaft, 324 - Tool retracting adjustment wheel, 33 - Wheel retracting assembly,

[0055] 4 - Flange, 41 - Second positioning protrusion,

[0056] 5 - Stroke adjustment rod, 51 - Trapezoidal groove, 52 - Stopper,

[0057] 6 - Workpiece. Detailed implementation mode

[0058] For the convenience of understanding the present invention, the present invention will be described in more detail below in conjunction with the accompanying drawings and specific embodiments.

[0059] It should be noted that in the present invention, "front" refers to the feed direction of the thread rolling head, "rear" refers to the direction opposite to the feed direction, "inner" refers to the direction close to the axis of the thread rolling head, and "outer" refers to the direction away from the axis of the thread rolling head.

[0060] Embodiment 1

[0061] An external thread rolling device, as Figure 1-2 shown, includes a thread rolling head 1, a tool expanding collision wheel device 2, a tool retracting device 3, a hydraulic feed device, a motor and a frame. The hydraulic feed device, the tool expanding collision wheel device 2 and the tool retracting device 3 are fixed on the frame, and the motor and the thread rolling head 1 are fixed on the moving platform at the mobile end of the hydraulic feed device. The hydraulic feed device provides the power for the front and back movement of the thread rolling head 1, and then drives the thread rolling head 1 to complete the rib stripping feed, thread rolling feed and tool retracting operations. The motor is connected to the thread rolling head 1 through a flange 4 to drive the thread rolling head 1 to rotate and complete the rotary rib stripping and rotary thread rolling.

[0062] The thread rolling head 1 includes a cylindrical frame body 11 and a rib stripping device 12, a tool expanding device 13, a thread rolling device 14 and a tool expanding wheel device 15 provided on the frame body 11;

[0063] The thread rolling device 14 includes 3 thread rolling wheel assemblies 141 symmetrically arranged in rotation on the frame body 11; the thread rolling wheel assembly 141 is as Figure 3 shown, including a thread rolling outer shell 1411 and a thread rolling wheel 1412 arranged inside the thread rolling outer shell 1411. The thread rolling wheel 1412 can roll axially relative to the thread rolling outer shell 1411. A first compression spring is provided between the frame body 11 and the thread rolling outer shell 1411, and the first compression spring enables the thread rolling outer shell 1411 to drive the thread rolling wheel 1412 to generate radial movement along the frame body 11. A first conical surface A is provided on the outer side surface of the thread rolling outer shell 1411, and the side with the larger diameter of the first conical surface A faces forward.

[0064] Fifteen expanding wheel devices 15 are sleeved on the outside of the thread rolling wheel assembly 141 and the frame body 11. The expanding and retracting operations of the thread rolling wheel assembly 141 can be realized by moving the expanding wheel device 15 forward and backward. The expanding wheel device 15 includes an expanding wheel ring 151 and an elastic limiting component 152. On the frame body 11, the expanding wheel ring 151 is axially positioned through the elastic limiting component 152. The inner surface of the expanding wheel ring 151 corresponding to the first conical surface A is provided with a smooth inclined curved surface C, and the conical slope of the smooth inclined curved surface C in the axial direction is equal to the conical slope of the first conical surface A. Through the cooperation of the first conical surface A and the smooth inclined curved surface C, the external thread rolling equipment can expand the wheel smoothly after the rolling process is completed.

[0065] Preferably, the outer side surface of the thread rolling shell 1411 is further provided with a second conical surface B whose conical slope is greater than that of the first conical surface A. The larger diameter side of the second conical surface B is smoothly transitioned and docked with the smaller diameter side of the first conical surface A through an arc. When expanding the wheel, the backward movement of the expanding wheel ring is smoother. Since the mechanical self-locking angle of steel (the expanding wheel ring 151, the thread rolling shell 1411, etc. are all made of steel) is generally 8.5°, in order to make the first conical surface A and the smooth inclined curved surface C generate mechanical self-locking, reduce the design difficulty of the elastic limiting component 152, and be able to expand the wheel smoothly, the conical slope of the first conical surface A is preferably 6° - 8°, and more preferably 7°.

[0066] Preferably, a conical pre-pressing groove 111 for elastically clamping the free end of the elastic limiting component 152 is provided on the outer surface of the frame body 11. To prevent the expanding wheel ring 151 from slipping due to vibration during the rib peeling and thread rolling processes. And when the external thread rolling equipment can complete the rolling process, the expanding wheel device 15 touches the expanding tool collision wheel 21. The expanding tool collision wheel 21 applies a backward pressure to the expanding wheel device 15 due to the feeding of the thread rolling headstock. When this pressure is greater than the locking force of the elastic limiting component 152 in the conical pre-pressing groove 111, the free end of the elastic limiting component 152 slides out of the conical pre-pressing groove 111. Furthermore, the expanding wheel ring 151 slides backward as a whole due to this backward pressure, and the thread rolling wheel assembly 141 pops outwards because there is no pressing effect of the smooth inclined curved surface C.

[0067] Preferably, the expanding wheel device 15 further includes an expanding wheel sliding sleeve 153 fixed to the rear end of the expanding wheel ring 151, or the expanding wheel ring 151 extends backward to form the expanding wheel sliding sleeve 153. The side wall of the expanding wheel sliding sleeve 153 is rotationally symmetrically provided with a plurality of radial holes. One end of the elastic limiting component 152 is fixed to the radial hole, and the other end is an elastic preloading end 15211; the elastic preloading end 15211 is clamped in the preloading groove 111 on the outer surface of the frame body, realizing the axial positioning of the expanding wheel ring 151 and the expanding wheel sliding sleeve 153. At the same time, the expanding wheel sliding sleeve 153 is provided with a convex block, and a through groove is provided on the outer surface of the corresponding frame body 11 in the front-back direction. Through the cooperation of the convex block and the groove, the expanding wheel sliding sleeve 153 can slide back and forth along the frame body 11.

[0068] Preferably, as Figure 4 shown, the elastic limiting component 152 includes a first elastic preloading pin 1521, an adjusting nut 1522, and a second compression spring 1523 sleeved on the first elastic preloading pin. One end of the first elastic preloading pin 1521 is fixed to the expanding wheel sliding sleeve 153 through the adjusting nut 1522, and the other end is the elastic preloading end 15211. The second compression spring 1523 is arranged between the adjusting nut 1522 and the upper end surface of the elastic preloading end 15211. The lower end surface of the elastic preloading end 15211 is arc-shaped; the arc-shaped elastic preloading end 15211 is matched with the taper of the conical preloading groove 111, which can not only prevent the expanding wheel ring 151 and the expanding wheel sliding sleeve 153 from slipping due to vibration during rib peeling and thread rolling, but also enable the first elastic preloading pin 1521 to slide out of the conical preloading groove 111 when subjected to a large axial pressure; thereby enabling the expanding wheel ring 151 to slide backward on the frame body 11 to realize wheel expansion. The adjusting nut 1522 is screwed into the radial threaded hole of the expanding wheel sliding sleeve 153, which is convenient for adjusting the depth of the adjusting nut 1522 screwed into the expanding wheel sliding sleeve 153 by rotating the adjusting nut 1522, adjusting the pressing force of the second compression spring 1523, and further adjusting the locking force of the elastic limiting component 152.

[0069] Embodiment 2

[0070] Differently from the above embodiment, as Figure 5As shown, the inner surface of the expanding wheel ring 151 is rotationally symmetrically provided with three smooth inclined curved surfaces C. The number of the smooth inclined curved surfaces C is the same as the number of the thread rolling wheel assemblies 141 or the number of the smooth inclined curved surfaces C is an integer multiple of the number of the thread rolling wheel assemblies 141. Axially of the expanding wheel ring 151, except that the taper of the smooth inclined curved surface C corresponds to the taper of the first conical surface A, on any cross-section of the expanding wheel ring 151 (the surface perpendicular to the axis of the expanding wheel ring 151, that is, the radial cross-section of the expanding wheel ring 151), the distance from the smooth inclined curved surface C to the axis of the expanding wheel ring 151 gradually decreases. By rotating the expanding wheel ring 151, the smooth inclined curved surface C forces the first conical surface A to move radially, and further, the thread rolling diameter of the workpiece to be processed can be changed, so that a set of thread rolling heads can process workpieces with a larger outer diameter range, such as the external threads of steel bars.

[0071] At this time, since the expanding wheel ring 151 needs to be adjusted forward and backward and / or the rotation angle needs to be adjusted to accurately position to the position corresponding to the diameter of the workpiece to be processed, and at the same time, it needs to be able to move backward smoothly when expanding the wheel to realize wheel expansion; the expanding wheel sleeve 153 is fixed to the expanding wheel ring 151 by fastening bolts. The expanding wheel sleeve 153 is rotationally symmetrically provided with a plurality of indexing annular holes 1531. Corresponding bolt holes are provided on the expanding wheel ring 151. The fastening bolts pass through the indexing annular holes 1531 and are fastened in the bolt holes. It is convenient to rotate the relative angle between the expanding wheel ring 151 and the expanding wheel sleeve 153, so that the smooth inclined curved surface C forces the first conical surface A to move radially, further changing the thread rolling diameter, so that a set of thread rolling heads can process workpieces with a larger outer diameter range, such as the external threads of steel bars. At the same time, to a certain extent, the continuous rotational positioning of the expanding wheel ring 151 can also be realized, and further, the rolling of the threads with non-standard steel bar diameters can be realized.

[0072] Preferably, the expanding wheel device 15 further includes a rear elastic pressing ring 154. The rear elastic pressing ring is fixed to the front end face of the expanding wheel ring 151 through an elastic preloading assembly 155. The elastic preloading assembly 155 includes a second elastic preloading pin 1551 and a third compression spring 1552 sleeved on the second elastic preloading pin 1551. One end of the second elastic preloading pin 1551 is fixed to the rear elastic pressing ring 155, and the other end is a free sliding end.

[0073] The outer diameter of the rear elastic pressing ring 154 is larger than the maximum outer diameter of the tool expanding device 13.

[0074] Preferably, the expanding wheel ring 151 includes an elastic preloading pin fixing portion 1511 and a rear elastic pressing ring sliding portion 1512 that are sequentially arranged in front of the expanding wheel sliding sleeve 153. The outer diameter of the elastic preloading pin fixing portion 1511 is greater than the outer diameter of the rear elastic pressing ring sliding portion 1512. The front end face of the elastic preloading pin fixing portion 1511 is provided with an elastic preloading pin sliding hole for axially sliding the free sliding end of the second elastic preloading pin 1551. The third spring 1552 is arranged between the rear elastic pressing ring 154 and the elastic preloading pin fixing portion 1511. On the front end face of the elastic preloading pin fixing portion 1511, a plurality of the elastic preloading pin sliding holes are rotationally symmetrically arranged. The front end of the rear elastic pressing ring sliding portion 1512 extends outward from the axis with a plurality of first positioning protrusions 15121. The rear elastic pressing ring 154 flexibly slides within the rear elastic pressing ring sliding portion 1512. When the thread rolling head 1 feeds until the rear elastic pressing ring 154 touches the tool expanding collision wheel 21 and continues to feed, after the retracting spring 1552 is compressed to the shortest, the rear elastic pressing ring 154 transfers the pressure to the expanding wheel ring 151 and the expanding wheel sliding sleeve 153, so that the free end of the elastic limiting component 152 slides out of the conical preloading groove 111, and the elastic force of the third spring 1552 is quickly released, causing the expanding wheel ring 151 and the expanding wheel sliding sleeve 153 to quickly rebound backward. The blocking effect of the expanding wheel ring 151 and the expanding wheel sliding sleeve 153 is reduced, and the efficiency and reliability of tool expansion are greatly improved.

[0075] Embodiment 3

[0076] Differently from the above embodiment, three elastic limiting threaded holes are rotationally symmetrically arranged on the side wall of the expanding wheel sliding sleeve 153. The axes of the elastic limiting threaded holes are arranged along the radial direction of the expanding wheel sliding sleeve 153. The adjusting nut 1522 of the elastic limiting component 152 is screwed into the elastic limiting threaded hole. Three conical preloading grooves 111 are formed on the outer surface of the corresponding frame body 11 to form a conical preloading groove group.

[0077] Preferably, along the axial direction of the frame body 11, a plurality of the conical preloading groove groups can be provided. When all the conical preloading grooves 111 are mapped to the same radial section before and after, they cannot overlap. In the optimal state, it is preferably that there is no overlapping part. Furthermore, by adjusting the front and rear locking positions of the expanding wheel ring 151 relative to the frame body 11, the position of the thread rolling outer shell 1411 relative to the axis of the frame body 11 can be adjusted. That is, by clamping the free end of the elastic limiting component 152 into the conical preloading grooves 111 at different axial positions of the frame body 11, the thread rolling wheel assembly 141 can be radially moved simultaneously, so as to meet the thread rolling processing requirements of workpieces with different diameters, such as steel bars.

[0078] Embodiment 4

[0079] Different from the above embodiments, the tool expanding device 13 of the external thread rolling equipment is sleeved outside the rib peeling device 12, and includes a tool expanding end cover 131, a tool expanding ring 132 and a tool expanding sliding sleeve 133. The rib peeling device 12 includes a plurality of rib peeling knives 121 arranged on the frame body. A fourth compression spring compressed radially along the frame body 11 is provided between the rib peeling knives 121 and the frame body 11. Corresponding to the rib peeling knives 121, a plurality of smooth curved surfaces are rotationally symmetrically arranged on the inner surface of the tool expanding ring 132. On any cross-section of the tool expanding ring 132, the distance from the smooth curved surface to the axis of the tool expanding ring gradually decreases along its circumferential direction. When the tool expanding ring 132 rotates relative to the tool expanding sliding sleeve 133, the distance from the rib peeling knives 121 to the axis of the frame body 11 gradually decreases. Thus, ribs can be peeled for workpieces with different diameters. Moreover, the setting manner of the tool expanding sliding sleeve 133 and the frame body refers to the setting manner of the tool expanding sliding sleeve 153 and the frame body 11.

[0080] Preferably, the outer diameter of the side of the flange 4 connected to the frame body 11 is equal to the outer diameter of the frame body 11, and a second positioning protrusion 41 extends outward from the side of the flange 4 connected to the motor towards the axis. The tool expanding device 15 can only rebound backward to the position where the second positioning protrusion 41 is located at most.

[0081] Embodiment 5

[0082] The external thread rolling equipment further includes a stroke adjustment rod 5 used in cooperation with the tool retracting device 3 and the tool expanding collision wheel device 2. As Figure 6 shown, the stroke adjustment rod 5 is fixed on the moving platform of the hydraulic feeding device and moves together with the thread rolling head 1. The stroke adjustment rod 5 is provided with a trapezoidal groove 51 and a stop block 52, and the stop block 52 is arranged in front of the trapezoidal groove 51.

[0083] The tool retracting device 3 includes a tool retracting support 31 arranged on the machine frame. A tool retracting assembly 32 and a tool retracting wheel assembly 33 are arranged on the tool retracting support 31.

[0084] The tool retracting assembly 32 includes a tool retracting collision wheel 321, a third elastic preloading pin 322, a tool retracting adjustment shaft 323 and a tool retracting adjustment wheel 324. A fifth compression spring is provided between the third elastic preloading pin 322 and the tool retracting support 31. The third elastic preloading pin 322 is perpendicular to the tool retracting adjustment shaft 323, and the tool retracting adjustment wheel 324 is installed on the tool retracting adjustment shaft 323.

[0085] During the tool retracting stroke, when the tool retracting adjustment wheel 324 is located in the trapezoidal groove 51, the fifth compression spring is in a relaxed state, and the tool retracting collision wheel 321 is in an internal position relative to the tool retracting support 31, completing the tool retracting.

[0086] During the feed stroke, the tool retraction adjustment wheel 324 rolls out of the trapezoidal groove 51, and then the outer side surface of the stroke adjustment rod 5 compresses the fifth compression spring. The tool retraction contact wheel 321 is in an external position relative to the tool retraction support 31, without affecting the axial feed of the expanding wheel device 15.

[0087] The tool expanding contact wheel device 2 includes a tool expanding contact wheel 21, a fourth elastic preloading pin 22, and a tool expanding support 23. A sixth compression spring is provided between the fourth elastic preloading pin 22 and the tool expanding support 23. One end of the fourth elastic preloading pin 22 is provided with the tool expanding contact wheel 21, and the other end extends outward through the tool expanding support 23 with a pressing shaft 221.

[0088] During the rib peeling feed stroke, the stop block 52 presses the preloading pin 22 inward, the sixth compression spring is in a compressed state, and the tool expanding contact wheel 21 is in an internal position relative to the tool expanding support 23, facilitating the contact between the tool expanding device 13 and the tool expanding contact wheel 21 after rib peeling is completed, and then completing tool expansion.

[0089] When tool expansion is completed, the stroke adjustment rod 5 advances just enough to disengage the preloading pin 22 from the stop block 52, and then the sixth compression spring returns to its relaxed state, causing the preloading pin 22 and the tool expanding contact wheel 21 to reset to the external position, without affecting the continued forward feed of the thread rolling head 1 with the rib peeling device 12 for thread rolling feed.

[0090] During the thread rolling feed stroke, the tool expanding contact wheel 21 in the external position can still touch the rear elastic pressing ring 154 (the outer diameter of the rear elastic pressing ring 154 is greater than the maximum outer diameter of the tool expanding device 13), and then the expanding wheel is completed.

[0091] Embodiment 6

[0092] A method for rolling the external thread of a steel bar using the above external thread rolling equipment includes the following steps:

[0093] S1. Obtain the diameter R of the workpiece 6 to be processed. By adjusting the position and / or rotation angle of the expanding wheel ring 151 relative to the frame body 11, change the contact position between the first conical surface A and the smooth inclined curved surface C, so that the thread rolling wheel assembly 141 moves radially, and make the radial distance between the thread rolling wheels 1412 just be able to process the workpiece 6 with a diameter of R;

[0094] S2. Clamp the workpiece 6 with a bench vice. The thread rolling head 1 rotates forward driven by the motor and simultaneously feeds forward along the axial direction of the workpiece 6 driven by the hydraulic feeding device. When the rib stripping tool 121 touches the workpiece, rib stripping starts and continues until the rib stripping is completed when the expanding tool device 13 touches the expanding tool contact wheel 21. At the same time, since the thread rolling head 1 continues to feed, the backward reaction force generated by the expanding tool contact wheel 21 on the expanding tool device 13 causes the expanding tool device 13 to spring back when this reaction force is greater than the pre-tightening force of the expanding tool sliding sleeve 133. The rib stripping tool 121 expands radially and separates from the workpiece 6 to complete tool expansion.

[0095] S3. The thread rolling head 1 continues to feed for thread rolling. The rear spring pressing ring 154 of the expanding wheel device 15 touches the expanding tool contact wheel 21. When the second compression spring 1523 is compressed to the limit position during continuous feeding, the thread rolling is completed. At the same time, since the thread rolling head 1 continues to feed, the backward reaction force generated by the expanding tool contact wheel 21 on the expanding wheel device 15 causes the expanding wheel device 15 to spring back quickly when this reaction force is greater than the pre-tightening force of the expanding wheel sliding sleeve 153. The thread rolling wheel assembly 141 expands radially to separate the workpiece 6 from the thread rolling wheel 1412 to complete wheel expansion.

[0096] S4. Stop feeding and quickly move backward. The tool retracting device 3 quickly resets the expanding wheel device 15 and the expanding tool device 13 to the tool retracting position, and the workpiece is taken out from the bench vice.

[0097] It should be noted that the above specific embodiments can enable those skilled in the art to understand the present invention more comprehensively, but do not limit the present invention in any way. Therefore, although this specification has described the present invention in detail with reference to the drawings and embodiments, those skilled in the art should understand that the present invention can still be modified or equivalently replaced. In short, all technical solutions and their changes that do not depart from the spirit and scope of the present invention should be covered by the protection scope of this invention patent.

Claims

1. An external thread rolling device, characterized in that, including a thread rolling head, which is driven to rotate by a motor; it includes a cylindrical frame body, a thread rolling device and a wheel expanding device; the thread rolling wheels of the thread rolling device are arranged on the frame body through a thread rolling outer shell, a first compression spring is arranged between the thread rolling outer shell and the frame body, a first conical surface is arranged on the outer side surface of the thread rolling outer shell, and the side with a larger diameter of the first conical surface faces forward; a wheel expanding device, sleeved on the outer sides of the thread rolling outer shell and the frame body, and realizing the wheel expanding and wheel retracting operations of the thread rolling wheels by moving back and forth along the frame body, including a wheel expanding ring and an elastic limiting component; the inner surface of the wheel expanding ring is provided with a smooth inclined curved surface corresponding to the first conical surface, and the conical slope of the smooth inclined curved surface in the axial direction is equal to the conical slope of the first conical surface; through the elastic limiting component, the wheel expanding ring realizes axially adjustable positioning on the frame body; a hydraulic feeding device, the moving end of which is provided with a moving platform for driving the thread rolling head and the motor to move back and forth; a fixed frame for carrying the fixed end of the hydraulic feeding device.

2. The external thread rolling equipment according to claim 1, characterized in that a plurality of smooth inclined curved surfaces are rotationally symmetrically arranged on the inner surface of the wheel expanding ring, the number of the smooth inclined curved surfaces is the same as the number of the thread rolling wheels or the number of the smooth inclined curved surfaces is an integer multiple of the number of the thread rolling wheels; and on any radial section of the wheel expanding ring, the distance from the smooth inclined curved surface to the axis of the wheel expanding ring gradually decreases along its circumference.

3. The external thread rolling equipment according to claim 1 or 2, characterized in that the wheel expanding device further includes a wheel expanding sliding sleeve fixed to the rear end of the wheel expanding ring or the wheel expanding ring extends backward to form a wheel expanding sliding sleeve, a plurality of radial holes are rotationally symmetrically arranged on the side wall of the wheel expanding sliding sleeve, one end of the elastic limiting component is fixed to the radial hole, and the other end is an elastically pre-pressed end; correspondingly, a pre-pressing groove group for clamping the elastically pre-pressed end is arranged on the frame body.

4. The external thread rolling equipment according to claim 1 or 2, characterized in that, a second conical surface with a conical slope greater than that of the first conical surface is further arranged on the outer side surface of the thread rolling outer shell, and the side with a larger diameter of the second conical surface is smoothly butted with the side with a smaller diameter of the first conical surface through an arc.

5. The external thread rolling equipment according to claim 1 or 2, characterized in that, the conical slope range of the first conical surface is 6° - 8°.

6. The external thread rolling equipment according to claim 5, characterized in that, the conical slope of the first conical surface is 7°.

7. The external thread rolling equipment according to claim 3, characterized in that, each pre-pressing groove in the pre-pressing groove group is a conical pre-pressing groove or an arc-shaped pre-pressing groove.

8. The external thread rolling equipment according to claim 3, characterized in that, the wheel expanding sliding sleeve and the wheel expanding ring are fixed together through fastening bolts, a plurality of indexing annular holes are rotationally symmetrically arranged on the wheel expanding sliding sleeve, and a plurality of bolt holes are arranged on the corresponding wheel expanding ring, and the fastening bolts pass through the indexing annular holes and are fastened in the bolt holes.

9. The external thread rolling equipment according to claim 3, characterized in that, the elastic limiting component includes a first elastically pre-pressed pin, an adjusting nut and a second compression spring sleeved on the first elastically pre-pressed pin, one end of the first elastically pre-pressed pin is fixed to the adjusting nut and the other end is an elastically free end, the second compression spring is between the adjusting nut and the upper convex platform of the elastically free end, and the lower end surface of the elastically free end is arc-shaped.

10. The external thread rolling equipment according to claim 9, characterized in that the adjusting nut is screwed on the wheel expanding sliding sleeve.

11. The external thread rolling equipment according to claim 1 or 2, characterized in that, The expansion wheel device also includes a rear spring pressure ring and an elastic pre-pressure assembly, the elastic pre-pressure assembly includes a second elastic pre-pressure pin and a third compression spring sleeved on the second elastic pre-pressure pin, one end of the second elastic pre-pressure pin is fixed to the rear spring pressure ring, and the other end is slidably connected to the axial pin hole set on the front end surface of the expansion wheel ring.

12. The external thread rolling equipment according to claim 3, characterized in that, The expansion ring includes an elastic pre-compression pin fixing portion and a rear spring pressure ring sliding portion which are sequentially arranged in front of the expansion sleeve. The outer diameter of the elastic pre-compression pin fixing portion is larger than the outer diameter of the rear spring pressure ring sliding portion. The front end surface of the elastic pre-compression pin fixing portion is provided with a plurality of elastic pre-compression pin sliding holes. The front end of the rear spring pressure ring sliding portion extends outward from the axis with a plurality of first positioning protrusions.

13. The external thread rolling equipment according to claim 1 or 2, characterized in that, It also includes a rib stripping device and a knife expanding device, the knife expanding device includes a knife expanding sleeve and a knife expanding ring arranged at the front end of the knife expanding sleeve, the rib stripping device includes a plurality of rib stripping knives arranged on the frame body, a fourth compression spring compressed along the radial direction of the frame body is provided between the rib stripping knife and the frame body, and a plurality of smooth curved surfaces are rotationally symmetrically provided on the inner surface of the knife expanding ring corresponding to the rib stripping knife, on any cross section of the knife expanding ring, the distance from the smooth curved surface to the axis of the expanding wheel ring along its circumference gradually decreases, so that the distance from the rib stripping knife to the axis of the expanding wheel ring gradually decreases.

14. The external thread rolling equipment according to claim 1 or 2, characterized in that It also includes a knife-retracting device, a knife-stretching and wheel-colliding device and a stroke adjustment rod; the stroke adjustment rod is fixed on the mobile platform of the hydraulic feed device, the stroke adjustment rod is provided with a trapezoidal groove and a stopper arranged in front of the trapezoidal groove, the knife-retracting device includes a knife-retracting support arranged on the frame, and the knife-retracting support is provided with a knife-retracting assembly and a wheel-retracting assembly.

15. The external thread rolling equipment according to claim 14, characterized in that, The knife-collecting assembly comprises a knife-collecting contact wheel, a third elastic pre-compression pin, a knife-collecting adjustment shaft and a knife-collecting adjustment wheel, a fifth compression spring being arranged between the third elastic pre-compression pin and the knife-collecting support; the third elastic pre-compression pin is arranged vertically to the knife-collecting adjustment shaft, and the knife-collecting adjustment wheel is installed on the knife-collecting adjustment shaft; when the knife is collected, the knife-collecting adjustment wheel is located in the trapezoidal groove, so that the fifth compression spring is in a relaxed state, and the knife-collecting contact wheel is in an internal position relative to the knife-collecting support; when feeding, the knife-collecting adjustment wheel rolls out of the trapezoidal groove, and then the outer side surface of the stroke adjustment rod makes the fifth compression spring in a compressed state, and the knife-collecting contact wheel is in an external position relative to the knife-collecting support.

16. The external thread rolling equipment according to claim 14, characterized in that, The knife-expanding wheel device comprises a knife-expanding wheel, a fourth elastic pre-compression pin and a knife-expanding support, a sixth compression spring is arranged between the fourth elastic pre-compression pin and the knife-expanding support, the knife-expanding wheel is arranged at one end of the fourth elastic pre-compression pin, and a pressure shaft is extended outward through the other end through the knife-expanding support; during rib peeling feeding, the block presses the pre-compression pin inward, the sixth compression spring is in a compressed state, and the knife-expanding wheel is in an internal position relative to the knife-expanding support, so that the knife-expanding device contacts the knife-expanding wheel; when the knife-expanding is completed, the stroke adjustment rod is fed forward until the pre-compression pin just disengages from the block, and the sixth compression spring resumes the relaxed state, so that the pre-compression pin and the knife-expanding wheel are reset to the external position.

17. The external thread rolling equipment according to claim 16, characterized in that, The expanding wheel device further includes a rear spring pressing ring and an elastic preloading assembly. The elastic preloading assembly includes a second elastic preloading pin and a third compression spring sleeved on the second elastic preloading pin. One end of the second elastic preloading pin is fixed to the rear spring pressing ring, and the other end is slidably connected to an axial pin hole provided on the front end face of the expanding wheel ring. The outer diameter of the rear spring pressing ring is greater than the maximum outer diameter of the tool expanding device, and the tool expanding collision wheel can still touch the rear spring pressing ring in the external position.

18. A method for thread rolling using the external thread rolling equipment according to any one of claims 1-17, comprising the following steps: S1. Obtain the diameter R of the workpiece to be processed. By adjusting the position and / or rotation angle of the expanding wheel ring relative to the frame body, change the contact position between the first conical surface and the smooth inclined curved surface, so that the thread rolling wheel assembly moves radially, so that the radial distance between the thread rolling wheels is just enough to process a workpiece with a diameter of R. S2. Clamp the workpiece with a vise. The thread rolling head rotates forward under the drive of the motor and simultaneously feeds forward along the axial direction of the workpiece under the drive of the hydraulic feeding device; when the rib stripping tool touches the workpiece, rib stripping starts until the tool expanding device touches the tool expanding collision wheel, and the rib stripping is completed; at the same time, since the thread rolling head continues to feed, the backward pressing force generated by the tool expanding collision wheel on the tool expanding device, when this pressing force is greater than the pre-tightening force of the tool expanding sliding sleeve, the tool expanding device rebounds backward, the rib stripping tool expands radially and separates from the workpiece, and the tool expanding is completed. S3. The thread rolling head continues to feed for thread rolling. When the expanding wheel device touches the tool expanding collision wheel and continues to feed, when the second compression spring is compressed to the limit position, the thread rolling is completed; at the same time, since the thread rolling head continues to feed, the backward pressing force generated by the tool expanding collision wheel on the expanding wheel device, when this pressing force is greater than the pre-tightening force of the expanding wheel sliding sleeve, the expanding wheel device quickly rebounds backward, the thread rolling wheel assembly expands radially, and the workpiece is separated from the thread rolling wheels, and the expanding wheel is completed. S4. Stop feeding and quickly move backward. The tool retracting device quickly resets the expanding wheel device and the tool expanding device to the tool retracting position, and takes out the workpiece from the vise.

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