External thread rolling machine head

Abstract

An external thread rolling machine head is provided with a first conical surface on the thread rolling shell, and a smooth inclined surface matching the first conical surface is provided on the inner surface of the expansion wheel ring, so that the external thread rolling machine head can smoothly expand the blade after the rolling process is completed. At the same time, by adjusting the front and rear position and / or rotation angle of the expansion wheel ring relative to the thread rolling machine head frame, the radial position of the thread rolling shell to the axis of the frame is adjusted, so that the thread rolling wheel of the thread rolling shell machine simultaneously moves radially, thereby being able to meet the thread rolling processing requirements of workpieces with different diameters, such as steel bars.

Description

Technical Field

[0001] The invention belongs to the technical field of external thread rolling equipment, and in particular relates to an external thread rolling machine head with high working efficiency, simple structure and the ability to process workpieces with different diameters. Background Art

[0002] At present, the external thread rolling device can only process workpieces with one outer diameter. Under the condition of the same pitch, the external thread of workpieces with different outer diameters needs to be processed by replacing the thread rolling wheel. Therefore, a set of rolling devices needs to be equipped with multiple sets of thread rolling heads, which greatly increases the cost of the device. After the processing is completed, the thread rolling head needs to be rotated in the opposite direction to remove the processed workpiece, which wastes processing time and reduces processing efficiency. Summary of the invention

[0003] The present invention provides an external thread rolling machine head, which can smoothly expand the cutter after the rolling process is completed by setting a first conical surface on the rolling shell and setting a smooth inclined surface matching the first conical surface on the inner surface of the expansion ring. At the same time, by adjusting the front and rear position and / or rotation angle of the expansion ring relative to the rolling machine head frame, the radial position of the rolling shell to the axis of the frame is adjusted, so that the rolling wheels of the rolling shell machine can simultaneously move radially, thereby meeting the needs of thread rolling processing of workpieces with different diameters, such as steel bars.

[0004] The technical solution of the present invention is as follows:

[0005] An external thread rolling machine head comprises a cylindrical frame, a thread rolling device and a wheel expansion device;

[0006] The thread rolling wheel of the thread rolling device is arranged on the frame through a thread rolling shell, a first compression spring is arranged between the thread rolling shell and the frame to generate radial movement, and a first conical surface is arranged on the outer side of the thread rolling shell, and the side with a larger diameter of the first conical surface faces forward;

[0007] The expansion wheel device is sleeved on the outer side of the thread rolling shell and the frame, and realizes the expansion and retraction operations of the thread rolling wheel by moving forward and backward along the frame, and includes an expansion wheel ring, an elastic limit assembly, a rear spring pressure ring and an elastic pre-stressing assembly; the inner surface of the expansion wheel ring is provided with a smooth inclined surface corresponding to the first conical surface, and the conical surface inclination of the smooth inclined surface in the axial direction is equal to the conical surface inclination of the first conical surface; the elastic pre-stressing assembly includes a second elastic pre-stressing pin and a second compression spring sleeved on the second elastic pre-stressing pin, one end of the second elastic pre-stressing pin is fixed to the rear spring pressure ring, and the other end is slidably connected to the axial pin hole provided on the front end surface of the expansion wheel ring;

[0008] On the frame, the expansion ring is axially adjustable in positioning through the elastic limiting assembly;

[0009] Preferably, the inner surface of the expansion ring is rotationally symmetrically provided with a plurality of smooth inclined surfaces, the number of the smooth inclined surfaces is the same as the number of the thread rolling wheel assemblies or the number of the smooth inclined surfaces is an integer multiple of the number of the thread rolling wheel assemblies; and on any radial cross-section of the expansion ring, the distance from the smooth inclined surface to the expansion ring axis gradually decreases along its circumference.

[0010] Preferably, the expansion wheel device also includes an expansion wheel sleeve fixed to the rear end of the expansion wheel ring or the expansion wheel ring is extended backward with an expansion wheel sleeve, the side wall of the expansion wheel sleeve is rotationally symmetrically provided with multiple radial holes, one end of the elastic limiting assembly is fixed to the radial holes, and the other end is an elastic pre-stressing end; correspondingly, the frame is provided with a pre-stressing groove group for clamping on the elastic pre-stressing end.

[0011] Preferably, the outer side surface of the thread rolling housing is further provided with a second conical surface with a conical surface slope greater than that of the first conical surface, and the side with a larger diameter of the second conical surface is smoothly connected with the side with a smaller diameter of the first conical surface through an arc.

[0012] Preferably, the cone slope of the first cone surface ranges from 6° to 8°.

[0013] Preferably, the first conical surface has a conical surface slope of 7°.

[0014] Preferably, each pre-pressing groove in the pre-pressing groove group is a conical pre-pressing groove or an arc-shaped pre-pressing groove.

[0015] Preferably, the expansion pulley sleeve and the expansion ring are fixed together by fastening bolts, and the expansion pulley sleeve is rotationally symmetrically provided with a plurality of graduated annular holes, and the corresponding expansion ring is provided with a plurality of bolt holes, and the fastening bolts pass through the graduated annular holes and are fastened in the bolt holes.

[0016] Preferably, the elastic limiting assembly includes a first elastic pre-compression pin, an adjusting nut and a third compression spring sleeved on the first elastic pre-compression pin, one end of the first elastic pre-compression pin is fixed to the adjusting nut and the other end is the elastic free end, the third compression spring is located between the adjusting nut and the upper boss of the elastic free end, and the lower end surface of the elastic free end is an arc shape.

[0017] Preferably, the adjusting nut is screwed onto the pulley sleeve.

[0018] Preferably, 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 second 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 front end surface of the expansion wheel ring.

[0019] Preferably, 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, and the front end of the rear spring pressure ring sliding portion extends outward from the axis with a plurality of first positioning protrusions.

[0020] Preferably, a plurality of the pre-compression groove groups are provided along the axial direction of the frame, and all the pre-compression grooves in the plurality of the pre-compression groove groups cannot be superimposed when mapped onto the same radial cross section of the frame.

[0021] Preferably, the frame is connected to the motor via a flange, the outer diameter of the side where the flange is connected to the frame is equal to the outer diameter of the frame, and a second positioning protrusion is extended outwardly from the axis on the side where the flange is connected to the motor.

[0022] The advantages of the present invention over the prior art are:

[0023] 1. The external thread rolling machine head of the present invention has a first conical surface on the outer side of the thread rolling shell, and a smooth inclined surface is provided on the inner surface of the expansion wheel ring corresponding to the first conical surface, and the cone slope of the smooth inclined surface in the axial direction is equal to the cone slope of the first conical surface; through the cooperation of the first conical surface and the smooth inclined surface, the external thread rolling machine head can smoothly expand the blade after the rolling process is completed. At the same time, by adjusting the front and rear positions of the expansion wheel ring relative to the thread rolling machine head, the radial position of the thread rolling shell to the axis of the frame is adjusted, that is, the expansion wheel can be clamped into the conical pre-stressing groove at different axial positions of the frame by the free end of the elastic limit assembly, so that the thread rolling wheel of the thread rolling shell machine can simultaneously produce radial movement, thereby being able to meet the thread rolling processing requirements of workpieces of different diameters such as steel bars.

[0024] 2. In the external thread rolling machine head described in the present invention, the inner surface of the expansion ring is rotationally symmetrically provided with a plurality of smooth inclined surfaces, the number of the smooth inclined surfaces is the same as the number of the rolling wheel assemblies or the number of the smooth inclined surfaces is an integer multiple of the number of the rolling wheel assemblies; on any cross section of the expansion ring, the distance from the smooth inclined surface to the axis of the expansion ring gradually decreases along its circumference, and by rotating the expansion ring, the smooth inclined surface forces the first conical surface to move radially, and the rolling diameter can be further changed, so that a set of rolling heads can process external threads of workpieces with a larger outer diameter range, such as steel bars.

[0025] 3. The external thread rolling machine head of the present invention sets a second conical surface with a larger conical surface slope behind the first conical surface, and makes a smooth arc transition between the first conical surface and the second conical surface, so that the backward movement of the wheel expansion ring is smoother during the rolling process. Among them, the theoretical mechanical self-locking angle of steel is generally 8.5°. Therefore, in order to make the wheel expansion ring produce a certain mechanical self-locking during the thread rolling process, reduce the design difficulty of the elastic limit assembly, and smoothly expand the wheel during the rolling process, the conical surface slope of the first conical surface is preferably 6°~8°, and more preferably 7°.

[0026] 4. The external thread rolling machine head described in the present invention has an expansion ring that needs to be adjusted forward and backward and / or the rotation angle adjusted to accurately position it at the position corresponding to the diameter of the workpiece to be processed, and at the same time needs to be able to move smoothly backward during expansion to achieve expansion. Therefore, the rear end of the expansion ring is designed with an expansion sleeve, and the expansion sleeve is designed with a dividing annular hole to achieve continuous rotation positioning of the expansion ring, thereby achieving the rolling of threads with non-standard steel bar diameters.

[0027] 5. The external thread rolling machine head of the present invention, the expansion wheel device also includes a rear spring pressure ring and a 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 fixed to the expansion wheel ring, so that when the wheel is expanded, the compression spring of the second elastic pre-pressure pin is rapidly released, and then the expansion wheel ring can quickly rebound relative to the rear spring pressure ring.

[0028] 6. The external thread rolling machine head of the present invention is designed with multiple elastic limit assemblies. The device uses a compression spring to make the first elastic pre-compression pin flexibly cooperate with the conical pre-compression groove on the frame body, so as to prevent the expansion wheel ring from sliding off due to vibration during the rib stripping process. The upper end of the first elastic pre-compression pin is fixed to the expansion wheel sleeve by an adjustment nut, and it is also convenient to adjust the locking force of the elastic limit assembly by rotating the adjustment nut to the depth of the expansion wheel sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the main cross-sectional structure of the external thread rolling machine head of the present invention;

[0030] Figure 2 It is a three-dimensional structural schematic diagram of the thread rolling wheel assembly of the external thread rolling machine head of the present invention;

[0031] Figure 3 It is a partial cross-sectional structural schematic diagram of the elastic limit assembly of the external thread rolling machine head of the present invention;

[0032] Figure 4 is a schematic diagram of a radial cross section of the external thread rolling machine head of the present invention;

[0033] Figure 5It is a schematic diagram of the top view of the external thread rolling equipment of the present invention;

[0034] Figure 6 The invention relates to the three-dimensional coordination of the stroke adjustment rod of the external thread rolling equipment, the knife expansion and contact wheel device, and the knife collection device.

[0035] The numbers in the figure are:

[0036] 1—thread rolling machine head, 11—frame, 111—conical pre-pressing groove, 12—rib stripping device, 121—rib stripping knife, 13—knife expansion device, 131—knife expansion end cover, 132—knife expansion ring, 133—knife expansion sliding sleeve,

[0037] 14—thread rolling device, 141—thread rolling wheel assembly, 1411—thread rolling housing, 1412—thread rolling wheel, A—first conical surface, B—second conical surface,

[0038] 15—inflation wheel device, 151—inflation wheel ring, C—smooth inclined surface, 1511—elastic pre-compression pin fixing portion, 1512—rear spring pressure ring sliding portion, 15121—first positioning protrusion, 152—elastic limiting component, 1521—first elastic pre-compression pin, 15211—elastic pre-compression end, 1522—adjusting nut, 1523—third compression spring, 153—inflation wheel sliding sleeve, 1531—gradient annular hole, 154—rear spring pressure ring, 155—elastic pre-compression component, 1551—second elastic pre-compression pin, 1552—second compression spring,

[0039] 2—knife-increasing wheel device, 21—knife-increasing wheel, 22—fourth elastic pre-pressing pin, 221—pressure shaft, 23—knife-increasing support,

[0040] 3—knife collecting device, 31—knife collecting support, 32—knife collecting assembly, 321—knife collecting wheel, 323—knife collecting adjustment shaft, 324—knife collecting adjustment wheel, 33—retracting wheel assembly,

[0041] 4—flange, 41—second positioning protrusion,

[0042] 5—travel adjustment rod, 51—trapezoidal groove, 52—stopper,

[0043] 6—Workpiece. DETAILED DESCRIPTION

[0044] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments.

[0045] It should be noted that the "front" mentioned in the present invention refers to the feed direction of the thread rolling head, the "rear" refers to the direction opposite to the feed direction, the "inside" refers to the axial direction close to the thread rolling head, and the "outside" refers to the axial direction away from the thread rolling head.

[0046] Example 1

[0047] An external thread rolling machine head 1, such as Figure 1 As shown, it comprises a cylindrical frame 11 and a rib stripping device 12, a knife expansion device 13, a thread rolling device 14, and a wheel expansion device 15 arranged on the frame 11;

[0048] The thread rolling device 14 includes three thread rolling wheel assemblies 141 which are rotationally symmetrically arranged on the frame 11; Figure 2 As shown, it includes a thread rolling housing 1411 and a thread rolling wheel 1412 disposed inside the thread rolling housing 1411, and the thread rolling wheel 1412 can roll relative to the thread rolling housing 1411 along the axial direction of the thread rolling wheel 1412. A first compression spring is disposed between the frame 11 and the thread rolling housing 1411, and the first compression spring enables the thread rolling housing 1411 to drive the thread rolling wheel 1412 to move radially along the frame 11, and a first conical surface A is disposed on the outer side of the thread rolling housing 1411, and the side with a larger diameter of the first conical surface A faces forward.

[0049] The wheel expansion device 15 is sleeved on the outer side of the thread rolling wheel assembly 141 and the frame 11, and the wheel expansion and retraction operations of the thread rolling wheel assembly 141 can be achieved by moving the wheel expansion device 15 forward and backward. The wheel expansion device 15 includes a wheel expansion ring 151 and an elastic limit assembly 152; on the frame 11, the wheel expansion ring 151 is axially positioned by the elastic limit assembly 152; the inner surface of the wheel expansion ring 151 corresponding to the first conical surface A is provided with a smooth inclined surface C, and the axial conical slope of the smooth inclined surface C 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 surface C, the external thread rolling machine head can be smoothly expanded after the rolling process is completed.

[0050] Preferably, the outer side surface of the thread rolling shell 1411 is also provided with a second conical surface B with a conical surface slope greater than the first conical surface A, and the side with a larger diameter of the second conical surface B is connected to the side with a smaller diameter of the first conical surface A through a circular arc smooth transition. When the wheel is expanded, the backward movement of the wheel expansion ring is smoother. Since the mechanical self-locking angle of steel (the wheel expansion ring 151, the thread rolling shell 1411, etc. are all steel) is generally 8.5°, in order to make the first conical surface A and the smooth inclined surface C produce mechanical self-locking, reduce the design difficulty of the elastic limit component 152, and enable smooth wheel expansion, the conical surface slope of the first conical surface A is preferably 6°~8°, and further preferably 7°.

[0051] Preferably, the outer surface of the frame 11 is provided with a conical pre-stressing groove 111 for elastically clamping the free end of the elastic limiting component 152. This prevents the expansion wheel ring 151 from slipping due to vibration during the rib stripping and thread rolling process. When the external thread rolling machine head is completed in the rolling process, the expansion wheel device 15 touches the expansion knife impact wheel 21, and the expansion knife impact wheel 21 applies backward pressure to the expansion wheel device 15 due to the feeding of the thread rolling machine head. When the pressure is greater than the locking force of the elastic limiting component 152 in the conical pre-stressing groove 111, the free end of the elastic limiting component 152 slides out of the conical pre-stressing groove 111, and then the expansion wheel ring 151 slides backward as a whole due to the backward pressure, and the thread rolling wheel component 141 pops out due to the lack of the pressing effect of the smooth inclined surface C.

[0052] Preferably, the expansion wheel device 15 further comprises a rear spring pressure ring 154, which is fixed to the front end surface of the expansion wheel ring 151 through an elastic pre-pressure component 155. The elastic pre-pressure component 155 comprises a second elastic pre-pressure pin 1551 and a second compression spring 1552 sleeved on the second elastic pre-pressure pin 1551. One end of the second elastic pre-pressure pin 1551 is fixed to the rear spring pressure ring 155, and the other end is a free sliding end.

[0053] The outer diameter of the rear spring ring 154 is greater than the maximum outer diameter of the blade expansion device 13 .

[0054] Preferably, the expansion ring 151 includes an elastic pre-compression pin fixing portion 1511 and a rear spring pressure ring sliding portion 1512 which are sequentially arranged in front of the expansion sleeve 153. The outer diameter of the elastic pre-compression pin fixing portion 1511 is larger than the outer diameter of the rear spring pressure ring sliding portion 1512. The front end surface of the elastic pre-compression pin fixing portion 1511 is provided with an elastic pre-compression pin sliding hole for axially sliding the free sliding end of the second elastic pre-compression pin 1551. The second compression spring 1552 is arranged between the rear spring pressure ring 154 and the elastic pre-compression pin fixing portion 1511. A plurality of the elastic pre-compression pin sliding holes are rotationally symmetrically arranged on the front end surface of the elastic pre-compression pin fixing portion 1511. A plurality of first positioning protrusions 15121 are extended outwardly from the front end of the rear spring pressure ring sliding portion 1512 toward the axis. The rear spring pressure ring 154 slides flexibly in the rear spring pressure ring sliding portion 1512. When the thread rolling machine head 1 is fed until the rear spring pressure ring 154 touches the knife expansion wheel 21 and continues to feed, after the second compression spring 1552 is compressed to the shortest, the rear spring pressure ring 154 transmits the pressure to the expansion wheel ring 151 and the expansion wheel sleeve 153, so that the free end of the elastic limit assembly 152 slides out of the conical pre-compression groove 111, and the elastic force of the second compression spring 1552 is quickly released, so that the expansion wheel ring 151 and the expansion wheel sleeve 153 quickly rebound. The blocking effect of the expansion wheel ring 151 and the expansion wheel sleeve 153 is reduced, and the efficiency and reliability of knife expansion are greatly improved.

[0055] Preferably, the wheel expansion device 15 also includes a wheel expansion sleeve 153 fixed to the rear end of the wheel expansion ring 151, or the wheel expansion ring 151 extends backward with a wheel expansion sleeve 153. The side wall of the wheel expansion sleeve 153 is rotationally symmetrically provided with a plurality of radial holes, one end of the elastic limit assembly 152 is fixed to the radial hole, and the other end is an elastic pre-stressing end 15211; the elastic pre-stressing end 15211 is snapped into the pre-stressing groove 111 on the outer surface of the frame body to achieve axial positioning of the wheel expansion ring 151 and the wheel expansion sleeve 153. At the same time, a protrusion is provided on the wheel expansion sleeve 153, and the corresponding outer surface of the frame body 11 is provided with a sliding groove that passes through from front to back. Through the cooperation of the protrusion and the sliding groove, the wheel expansion sleeve 153 can slide forward and backward along the frame body 11.

[0056] As a preference, Figure 3As shown, the elastic limiting assembly 152 includes a first elastic pre-compression pin 1521, an adjusting nut 1522 and a third compression spring 1523 sleeved on the first elastic pre-compression pin, one end of the first elastic pre-compression pin 1521 is fixed to the pulley sleeve 153 through the adjusting nut 1522, and the other end is the elastic pre-compression end 15211, and the third compression spring 1523 is arranged between the adjusting nut 1522 and the upper end surface of the elastic pre-compression end 15211. The lower end surface of the elastic pre-stressing end 15211 is in an arc shape; the elastic pre-stressing end 15211 with an arc shape is matched with the conical surface slope of the conical pre-stressing groove 111, which can not only prevent the expansion ring 151 and the expansion sleeve 153 from sliding off due to vibration during the rib stripping and thread rolling process, but also enable the first elastic pre-stressing pin 1521 to slide out of the conical pre-stressing groove 111 when subjected to a large axial pressure; thereby enabling the expansion ring 151 to slide backward on the frame 11 to achieve expansion. The adjusting nut 1522 is screwed into the radial threaded hole of the expansion sleeve 153, so that the compression force of the third compression spring 1523 can be adjusted by rotating the adjusting nut 1522 to screw into the depth of the expansion sleeve 153, thereby adjusting the locking force of the elastic limit assembly 152.

[0057] Example 2

[0058] Different from the above embodiment, Figure 4 As shown, the inner surface of the expansion ring 151 is rotationally symmetrically provided with three smooth inclined surfaces C, and the number of the smooth inclined surfaces C is the same as the number of the rolling wheel assemblies 141 or the number of the smooth inclined surfaces C is an integer multiple of the number of the rolling wheel assemblies 141. In the axial direction of the expansion ring 151, in addition to the cone slope of the smooth inclined surface C corresponding to the cone slope of the first conical surface A, on any cross section of the expansion ring 151 (the surface perpendicular to the axis of the expansion ring 151, that is, the radial cross section of the expansion ring 151), the distance from the smooth inclined surface C to the axis of the expansion ring 151 gradually decreases. By rotating the expansion ring 151, the smooth inclined surface C forces the first conical surface A to move radially, and further changes the rolling diameter of the workpiece to be processed, so that a set of rolling heads can process workpieces with a larger outer diameter range, such as the external thread of steel bars.

[0059] At this time, since the expansion ring 151 needs to be adjusted forward and backward and / or rotated at an angle to accurately locate the position corresponding to the diameter of the workpiece being processed, and at the same time needs to be able to move smoothly backward during expansion to achieve expansion; the expansion sleeve 153 is fixed to the expansion ring 151 by fastening bolts, and the expansion sleeve 153 is rotationally symmetrically provided with a plurality of graduated annular holes 1531, and the corresponding expansion ring 151 is provided with a plurality of bolt holes, and the fastening bolts pass through the graduated annular holes 1531 and are fastened in the bolt holes. It is convenient to rotate the relative angle between the expansion ring 151 and the expansion sleeve 153, so that the smooth inclined 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 the external threads of workpieces with a larger outer diameter range, such as steel bars. At the same time, the continuous rotation positioning of the expansion ring 151 can also be achieved to a certain extent, thereby realizing the rolling of threads with non-standard steel bar diameters.

[0060] Second compression spring Second compression spring Embodiment 3

[0061] Different from the above embodiment, three elastic limiting threaded holes are rotationally symmetrically arranged on the side wall of the expansion sleeve 153, the axis of the elastic limiting threaded holes is arranged along the radial direction of the expansion sleeve 153, and the adjusting nut 1522 of the elastic limiting assembly 152 is screwed into the elastic limiting threaded hole. Correspondingly, three conical pre-compression grooves 111 are arranged on the outer surface of the frame 11 to form a conical pre-compression groove group.

[0062] Preferably, a plurality of the conical pre-stressing groove groups can be provided along the axial direction of the frame 11, and when all the conical pre-stressing grooves 111 are mapped to the same radial cross section from front to back, they cannot overlap. In the optimal state, preferably, there cannot be any overlapping parts. Furthermore, the position of the thread rolling housing 1411 to the axis of the frame 11 can be adjusted by adjusting the front and rear locking positions of the expansion ring 151 relative to the frame 11, that is, the free end of the elastic limit assembly 152 can be clamped into the conical pre-stressing grooves 111 at different axial positions of the frame 11, so that the thread rolling wheel assembly 141 can simultaneously generate radial movement, thereby being able to meet the thread rolling processing requirements of workpieces of different diameters, such as steel bars.

[0063] Example 4

[0064] Different from the above-mentioned embodiment, the knife expansion device 13 of the external thread rolling machine head is sleeved on the outside of the rib stripping device 12, including a knife expansion end cover 131, a knife expansion ring 132 and a knife expansion sleeve 133. The rib stripping device 12 includes a plurality of rib stripping knives 121 arranged on the frame body, and a fourth compression spring is provided between the rib stripping knives 121 and the frame body 11, which is compressed radially along the frame body 11. The inner surface of the knife expansion ring 132 is rotationally symmetrically provided with a plurality of smooth curved surfaces corresponding to the rib stripping knives 121. On any cross section of the knife expansion ring 132, the distance from the smooth curved surface to the axis of the expansion wheel ring along its circumference gradually decreases, so that when the knife expansion ring 132 rotates relative to the knife expansion sleeve 133, the distance from the rib stripping knife 121 to the axis of the frame body 11 gradually decreases. In this way, ribs can be stripped for workpieces of different diameters. Moreover, the arrangement between the knife expansion sleeve 133 and the frame body refers to the arrangement between the expansion wheel sleeve 153 and the frame body 11.

[0065] Preferably, the outer diameter of the side where the flange 4 is connected to the frame 11 is equal to the outer diameter of the frame 11, and the side where the flange 4 is connected to the motor has a second positioning protrusion 41 extending outward from the axis. The expansion wheel device 15 can only rebound to the position where the second positioning protrusion 41 is located at most.

[0066] Example 5

[0067] An external thread rolling device, such as Figure 5-6 As shown, it includes a thread rolling machine head 1, a knife-expanding and impacting wheel device 2, a knife-collecting device 3, a hydraulic feeding device, a motor and a frame. The hydraulic feeding device, the knife-expanding and impacting wheel device 2 and the knife-collecting device 3 are fixed on the frame, and the motor and the thread rolling machine head 1 are fixed on the mobile platform at the mobile end of the hydraulic feeding device. The hydraulic feeding device provides the thread rolling machine head 1 with power to move forward and backward, thereby driving the thread rolling machine head 1 to complete rib stripping feeding, thread rolling feeding and knife-collecting operations. The motor is connected to the thread rolling machine head 1 through a flange 4, driving the thread rolling machine head 1 to rotate, completing rotary rib stripping and rotary thread rolling.

[0068] The external thread rolling device also includes a stroke adjustment rod 5 used in conjunction with the knife collection device 3 and the knife expansion and contact wheel device 2. Figure 6 As shown, the stroke adjustment rod 5 is fixed on the moving platform of the hydraulic feeding device and moves with the thread rolling machine head 1. The stroke adjustment rod 5 is provided with a trapezoidal groove 51 and a stopper 52, and the stopper 52 is arranged in front of the trapezoidal groove 51.

[0069] The knife collecting device 3 comprises a knife collecting support 31 arranged on the frame, and a knife collecting assembly 32 and a wheel collecting assembly 33 are arranged on the knife collecting support 31.

[0070] The knife collection assembly 32 includes a knife collection wheel 321, a third elastic pre-compression pin, a knife collection adjustment shaft 323 and a knife collection adjustment wheel 324, and a fifth compression spring is provided between the third elastic pre-compression pin and the knife collection support 31. The third elastic pre-compression pin is vertically arranged with the knife collection adjustment shaft 323, and the knife collection adjustment wheel 324 is mounted on the knife collection adjustment shaft 323.

[0071] During the knife-retracting stroke, when the knife-retracting adjustment wheel 324 is located in the trapezoidal groove 51, the fifth compression spring is in a relaxed state, and the knife-retracting contact wheel 321 is in a built-in position relative to the knife-retracting support 31, completing the knife-retracting.

[0072] During the feeding stroke, the knife-collecting adjustment wheel 324 rolls out from the trapezoidal groove 51, and then the outer side surface of the stroke adjustment rod 5 makes the fifth compression spring in a compressed state, and the knife-collecting contact wheel 321 is in an outward position relative to the knife-collecting support 31, which does not affect the axial feeding of the expansion wheel device 15.

[0073] The knife-increasing wheel device 2 includes a knife-increasing wheel 21, a fourth elastic pre-compression pin 22 and a knife-increasing support 23, a sixth compression spring is provided between the fourth elastic pre-compression pin 22 and the knife-increasing support 23, the knife-increasing wheel 21 is provided at one end of the fourth elastic pre-compression pin 22, and a pressure shaft 221 extends outwardly through the knife-increasing support 23 at the other end.

[0074] During the rib stripping feeding stroke, the block 52 presses the pre-compression pin 22 inward, the sixth compression spring is in a compressed state, and the knife-raising wheel 21 is in an internal position relative to the knife-raising support 23, so that after the rib stripping is completed, the knife-raising device 13 contacts the knife-raising wheel 21 to complete the knife-raising.

[0075] When the knife expansion is completed, the stroke adjustment rod 5 is fed forward to just make the pre-compression pin 22 disengage from the block 52, and then the sixth compression spring returns to the relaxed state, so that the pre-compression pin 22 and the knife expansion wheel 21 are reset to the external position, without affecting the thread rolling machine head 1 to continue to feed forward with the rib stripping device 12 for thread rolling.

[0076] During the thread rolling feeding stroke, the knife expansion wheel 21 can still touch the rear spring ring 154 (the outer diameter of the rear spring ring 154 is larger than the maximum outer diameter of the knife expansion device 13) in the external position, thereby completing the expansion wheel.

[0077] Example 6

[0078] The method for rolling the external thread of a steel bar using the external thread rolling equipment comprises the following steps:

[0079] S1, obtaining the diameter R of the workpiece 6 to be processed, and changing the contact position between the first conical surface A and the smooth inclined surface C by adjusting the position and / or rotation angle of the expansion ring 151 relative to the frame 11, so that the thread rolling wheel assembly 141 moves radially, so that the radial distance between the thread rolling wheels 1412 is just enough to process the workpiece 6 with a diameter of R;

[0080] S2, clamp the workpiece 6 with a vise, the thread rolling machine head 1 rotates forward under the drive of the motor, and at the same time, feeds forward along the axial direction of the workpiece 6 under the drive of the hydraulic feeding device; when the rib stripping knife 121 touches the workpiece, the rib stripping begins, and the rib stripping is completed when the knife expansion device 13 touches the knife expansion wheel 21; at the same time, as the thread rolling machine head 1 continues to feed, the knife expansion wheel 21 generates a backward pressure on the knife expansion device 13, and when the pressure is greater than the preload force of the knife expansion sliding sleeve 133, the knife expansion device 13 rebounds, and the rib stripping knife 121 expands radially and separates from the workpiece 6, completing the knife expansion;

[0081] S3, the thread rolling machine head 1 continues to feed, and the thread rolling process is carried out. The rear spring pressure ring 154 of the expansion wheel device 15 touches the expansion knife contact wheel 21, and the feeding continues. When the third compression spring 1523 is compressed to the limit position, the thread rolling process is completed; at the same time, as the thread rolling machine head 1 continues to feed, the expansion knife contact wheel 21 generates a backward pressure on the expansion wheel device 15. When the pressure is greater than the preload force of the expansion wheel sleeve 153, the expansion wheel device 15 quickly rebounds, and the rolling wheel assembly 141 expands radially, so that the workpiece 6 is separated from the rolling wheel 1412, and the expansion wheel is completed;

[0082] S4, stop feeding and quickly move back, the knife collecting device 3 quickly resets the wheel expansion device 15 and the knife expansion device 13 to the knife collecting position, and takes out the workpiece from the vise.

[0083] It should be noted that the above-described specific embodiments can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described 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 replaced by equivalents. In short, all technical solutions and changes that do not deviate from the spirit and scope of the present invention should be included in the protection scope of the patent of the present invention.

Claims

1. An external thread rolling machine head, characterized in that: It includes a cylindrical frame, a thread rolling device and a wheel expansion device; The thread rolling wheel of the thread rolling device is arranged on the frame through a thread rolling shell, a first compression spring is arranged between the thread rolling shell and the frame, and a first conical surface is arranged on the outer side of the thread rolling shell, and the side with a larger diameter of the first conical surface faces forward; The expansion wheel device is sleeved on the outer side of the thread rolling shell and the frame, and realizes the expansion and retraction operation of the thread rolling wheel by moving forward and backward along the frame, and includes an expansion wheel ring, an elastic limit assembly, a rear spring pressure ring and an elastic pre-stressing assembly; the inner surface of the expansion wheel ring is provided with a smooth inclined surface corresponding to the first conical surface, and the conical surface inclination of the smooth inclined surface in the axial direction is equal to the conical surface inclination of the first conical surface; the elastic pre-stressing assembly includes a second elastic pre-stressing pin and a second compression spring sleeved on the second elastic pre-stressing pin, one end of the second elastic pre-stressing pin is fixed to the rear spring pressure ring, and the other end is slidably connected to the pin hole of the expansion wheel ring; On the frame, the expansion ring is axially adjustable in positioning through the elastic limiting assembly.

2. The external thread rolling machine head according to claim 1, characterized in that: The inner surface of the expansion ring is rotationally symmetrically provided with a plurality of smooth inclined surfaces, the number of the smooth inclined surfaces is the same as the number of the thread rolling wheels or the number of the smooth inclined surfaces is an integer multiple of the number of the thread rolling wheels; and on any radial cross section of the expansion ring, the distance from the smooth inclined surface to the axis of the expansion ring gradually decreases along its circumference.

3. The external thread rolling machine head according to claim 1 or 2, characterized in that: The expansion wheel device also includes an expansion wheel sleeve fixed to the rear end of the expansion wheel ring or an expansion wheel sleeve extending backward from the expansion wheel ring, and the side wall of the expansion wheel sleeve is rotationally symmetrically provided with multiple radial holes, one end of the elastic limiting component is fixed to the radial hole, and the other end is an elastic pre-stressing end; correspondingly, the frame is provided with a pre-stressing groove group for clamping on the elastic pre-stressing end.

4. The external thread rolling machine head according to claim 1 or 2, characterized in that: The outer side surface of the thread rolling housing is also provided with a second conical surface with a conical surface slope greater than that of the first conical surface, and the side with a larger diameter of the second conical surface is smoothly connected with the side with a smaller diameter of the first conical surface through an arc.

5. The external thread rolling machine head according to claim 1 or 2, characterized in that: The cone slope of the first cone surface ranges from 6° to 8°.

6. The external thread rolling machine head according to claim 5, characterized in that: The first conical surface has a conical surface slope of 7°.

7. The external thread rolling machine head 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 machine head according to claim 3, characterized in that: The expansion pulley sleeve and the expansion ring are fixed together by fastening bolts. The expansion pulley sleeve is rotationally symmetrically provided with a plurality of graduated annular holes, and the corresponding expansion ring is provided with a plurality of bolt holes. The fastening bolts pass through the graduated annular holes and are fastened in the bolt holes.

9. The external thread rolling machine head according to claim 3, characterized in that: The elastic limiting assembly includes a first elastic pre-compression pin, an adjusting nut and a third compression spring sleeved on the first elastic pre-compression pin, one end of the first elastic pre-compression pin is fixed to the adjusting nut and the other end is an elastic free end, the third compression spring is located between the adjusting nut and the upper boss of the elastic free end, and the lower end surface of the elastic free end is an arc shape.

10. The external thread rolling machine head according to claim 9, characterized in that: The adjusting nut is screwed to the expansion pulley sleeve.

11. The external thread rolling machine head 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.

12. The external thread rolling machine head according to claim 3, characterized in that: A plurality of pre-compression groove groups are provided along the axial direction of the frame, and all pre-compression grooves in the plurality of pre-compression groove groups cannot be superimposed when mapped onto the same radial cross section of the frame.

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