Camshaft angular positioning device for numerical control machining center
Patent Information
- Application Number
- CN202522264653.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-27
- Publication Date
- 2026-10-20
- Estimated Expiration
- 2035-10-27
AI Technical Summary
凸轮轴在数控加工中心上进行车削加工时，需要将凸轮轴稳定的水平架设在指定的工位上，而且需要保证加工时，凸轮轴工件无论是在轴向方向上还是在角向方向上都不能发生任何移位，否则就有可能造成车削刀具发生“崩刀”或者加工出来的凸轮轴不合格，通常来说凸轮轴在轴向方向上的定位相对容易，而在角向方向上的定位往往存在一定的难度，因为刀具对凸轮轴的轴表面及凸轮结构表面进行车削加工时，凸轮轴角向方向上会受到相当大的旋转扭矩，然而为了避免凸轮轴端部受压变形，凸轮轴端部的夹持力度又不能太大，目前加工中心的工作台上又缺乏相应的凸轮轴角向定位装置，因此，加工过程中存在凸轮轴发生角向扭转的风险，难以保证凸轮轴的加工质量，而且还容易造成刀具损坏，因此，很有必要专门为加工中心设计一种凸轮轴角向定位装置
本实用新型提供的一种数控加工中心用凸轮轴角向定位装置，能够准确的保证凸轮轴在加工中心定位工装上轴向定位以及角向定位，可以有效保护加工中心的车削刀具，尽可能的降低“崩刀”故障的发生，同时能够有效的保证凸轮轴的加工质量，提高凸轮轴产品加工的整体品质保障和经济效益。
Smart Images
Figure CN224866867U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of camshaft machining technology, specifically relating to a camshaft angular positioning device for CNC machining centers. Background Technology
[0002] The camshaft is a crucial component of an internal combustion engine. Its manufacturing process involves multiple steps, including billet casting, rough machining, semi-finishing, finishing, and final finishing. Semi-finishing of the camshaft is typically performed on CNC machining centers. The "camshaft rotation angle" refers to the relative rotation angle of the camshaft in an internal combustion engine, used to control the opening and closing of valves, thus affecting the engine's intake and exhaust processes. The camshaft rotation angle is closely related to engine performance, combustion efficiency, and emissions; therefore, precise control of its rotation angle is essential in engine design and tuning to ensure optimal combustion efficiency and power output. When a camshaft is machined on a CNC machining center, it needs to be stably and horizontally mounted on a designated workstation. Furthermore, it must be ensured that the camshaft workpiece does not shift in either the axial or angular directions during machining. Otherwise, the turning tool may break or the machined camshaft may be defective. Generally, axial positioning of the camshaft is relatively easy, but angular positioning is often more challenging. This is because when the tool turns the camshaft's shaft surface and cam structure surface, the camshaft is subjected to considerable rotational torque in the angular direction. However, to avoid deformation of the camshaft end, the clamping force at the camshaft end cannot be too large. Currently, machining centers lack corresponding camshaft angular positioning devices on their worktables. Therefore, there is a risk of camshaft angular torsion during machining, making it difficult to guarantee the machining quality and easily causing tool damage. Thus, it is essential to design a camshaft angular positioning device specifically for machining centers. Utility Model Content
[0003] In response to the above situation, this utility model provides a camshaft angular positioning device for CNC machining centers, which can not only ensure the stable positioning of the camshaft in the axial direction, but also effectively ensure the possible positioning of the camshaft in the angular direction, thus effectively avoiding equipment failure and product quality problems caused by workpiece displacement during camshaft machining.
[0004] To achieve the above objectives, the present invention adopts the following technical solution: A camshaft angular positioning device for a CNC machining center includes a camshaft, a machining center, a worktable, and a cutting tool. The worktable is provided with a rotary chuck for clamping the head end of the camshaft and a rotary ejector for pressing the tail end of the camshaft. The rotary chuck is rotatably connected to the upper right side of the worktable via a drive motor. The rotary ejector is rotatably connected to the upper left side of the worktable via a support base. A positioning fixture for clamping the camshaft is provided between the support base and the drive motor. The positioning fixture includes a head bracket and a tail bracket for cooperating to lift the head and tail ends of the camshaft, and a middle pressing bracket for supporting, lifting, and axially positioning the camshaft. The central top-pressure bracket includes an L-shaped mounting base, a top-pressure slider, and a top-pressure cylinder. The L-shaped mounting base is fixedly connected to the top of the workbench. The top-pressure slider is slidably mounted on the upper right horizontal side wall of the L-shaped mounting base. The top-pressure cylinder is horizontally mounted on the left side of the vertical side wall of the L-shaped mounting base. The piston rod of the top-pressure cylinder passes through the vertical side wall of the L-shaped mounting base and connects to the top-pressure slider. The top of the top-pressure slider is provided with a V-shaped groove, which is engaged between the two cam structures in the middle of the camshaft. When the top-pressure cylinder pushes the top-pressure slider to the right, the top right side wall of the top-pressure slider can exert a rightward pushing force on the left side wall of the right cam structure. The left side wall of the rotary chuck is provided with a clamping and positioning mechanism, and an angular positioning mechanism for angular positioning of the head end of the camshaft. The clamping and positioning mechanism includes two symmetrically arranged positioning arms that can form a clamping and enveloping effect on the circumferential surface of the head end of the camshaft. The ends of the two positioning arms are provided with C-shaped grooves that match the circumferential surface of the head end of the camshaft. The angular positioning mechanism includes a positioning connecting seat located between the two positioning arms. A central positioning pin for positioning the center hole of the end face of the camshaft is fixedly provided in the middle of the positioning connecting seat. An eccentric positioning pin for positioning the angular positioning groove of the camshaft is provided on one side of the central positioning pin. Furthermore, the positioning fixture includes a fixed base plate fixedly connected to the worktable. The head bracket and the tail bracket have the same structure, including an L-shaped positioning seat locked to the fixed base plate and a V-shaped support plate connected above the L-shaped positioning seat. The upper end of the V-shaped support plate is provided with a second V-shaped slot. The second V-shaped slots of the head bracket and the tail bracket are respectively engaged between the two cam structures at the head end and the two cam structures at the tail end of the camshaft.
[0005] Furthermore, the vertical sidewall of the L-shaped positioning seat is provided with two vertically extending adjustment holes, and two adjustment screws are respectively inserted through the two adjustment holes. The V-shaped support plate is provided with corresponding locking screw holes, which are used to realize the up-and-down sliding adjustment of the V-shaped support plate on one side of the vertical sidewall of the L-shaped positioning seat, thereby realizing the overall extension and retraction adjustment of the support height of the head bracket and the tail bracket.
[0006] Furthermore, a linear slide rail extending in the left-right direction is fixedly laid on the horizontal side wall of the L-shaped mounting base, and a linear slider is provided at the bottom of the top-pressing slider to enable the top-pressing slider to slide left and right along the upper surface of the horizontal side wall of the L-shaped mounting base under the action of the top-pressing cylinder.
[0007] Furthermore, a pair of rollable support rollers are symmetrically arranged on the inner sides of the two side walls of the V-shaped groove, and the inner upper roller surfaces of the two support rollers are in rolling contact with the lower circumferential surface of the camshaft.
[0008] Furthermore, the top right side wall of the pressing slider is provided with a bullseye ball that can roll in all directions, and the top right side wall of the pressing slider pushes the left side wall of the right cam structure through the bullseye ball.
[0009] Furthermore, the bottom of the L-shaped positioning seat is locked to the fixed base plate via an adjusting base plate. The adjusting base plate, the L-shaped positioning seats of the head bracket and the tail bracket are all locked to the fixed base plate via "U"-shaped sliding nuts. The fixed base plate is provided with "U"-shaped transverse track grooves that allow the sliding nuts to slide left and right. That is, the left and right positions of the head bracket, the tail bracket and the middle top pressure bracket on the worktable can all be adjusted.
[0010] Furthermore, a radially convex longitudinal track groove is formed on the left side wall of the rotary chuck. Two convex locking nuts are fitted within the longitudinal track groove. The two positioning arms are correspondingly locked to the rotary chuck via locking bolts and the two locking nuts. The circumferential distance between the two positioning arms can be adjusted appropriately to accommodate the head diameter of camshafts of different specifications.
[0011] Furthermore, each of the four corners of the positioning connector is fixedly connected to the rotary chuck by fixing bolts. The central positioning post and the eccentric positioning pin are integrally fixed to the positioning connector. A central hole is opened at the center of the end face of the camshaft head end. The central positioning post is shaped like a frustum cone, which facilitates its insertion into the central hole. A semi-circular notch-shaped angular positioning groove is opened on the end face of the camshaft on one side of the central hole. The eccentric positioning pin is cylindrical and can be just locked into the angular positioning groove to prevent the camshaft from rotating in the circumferential direction, thereby realizing angular positioning during camshaft machining.
[0012] This utility model also includes other components that enable its normal use, all of which are conventional means in the field. In addition, any devices or components not limited in this utility model adopt the prior art in the field.
[0013] The beneficial effects of this utility model are as follows: This utility model provides a camshaft angular positioning device for CNC machining centers, which can accurately ensure the axial and angular positioning of the camshaft on the positioning fixture of the machining center. It can effectively protect the turning tools of the machining center, minimize the occurrence of "tool breakage" failure, and effectively ensure the machining quality of the camshaft, thereby improving the overall quality assurance and economic benefits of camshaft product machining. Attached Figure Description
[0014] Figure 1 This is a three-dimensional structural diagram of the camshaft in this utility model; Figure 2 This is a schematic diagram of the angular positioning device in the embodiment; Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure along the AA direction; Figure 4 for Figure 2 A schematic diagram of the cross-sectional structure along the BB direction; Figure 5 for Figure 2 A schematic diagram of the cross-sectional structure along the CC direction; Figure 6 for Figure 2 Enlarged structural diagram of section D in the middle; Figure 7 for Figure 2 Enlarged structural diagram of section E. Detailed Implementation
[0015] The present invention will now be clearly described with reference to the accompanying drawings and specific embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art based on the embodiments of the present invention without creative effort to obtain all other embodiments should be included within the protection scope of the present invention.
[0016] In the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "inner," "outer," "center," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0017] Example like Figure 1-7 As shown, a camshaft angular positioning device for a CNC machining center includes a camshaft 1, a machining center, a worktable 2, and a cutting tool 3. The worktable is equipped with a rotary chuck 4 for clamping the head end of the camshaft and a rotary ejector 5 for pressing the tail end of the camshaft. The rotary chuck is rotatably connected to the upper right side of the worktable via a drive motor 6. The rotary ejector is rotatably connected to the upper left side of the worktable via a support base 7. A positioning fixture for clamping the camshaft is provided between the support base and the drive motor. The positioning fixture includes a head bracket and a tail bracket for supporting and lifting the head and tail ends of the camshaft, and a central pressing bracket for supporting, lifting, and axially positioning the camshaft. The camshaft, the worktable of the machining center, and the cutting tool described above are all prior art and will not be described in detail here.
[0018] The central top-pressing bracket includes an L-shaped mounting base 8, a top-pressing slider 9, and a top-pressing cylinder 10. The L-shaped mounting base is fixedly connected to the top of the worktable. The top-pressing slider is slidably mounted on the upper right horizontal side wall of the L-shaped mounting base. The top-pressing cylinder is horizontally mounted on the left side of the vertical side wall of the L-shaped mounting base. The piston rod of the top-pressing cylinder passes through the vertical side wall of the L-shaped mounting base and connects to the top-pressing slider. The top of the top-pressing slider is provided with a V-shaped groove 11, which is engaged between the two cam structures 34 in the middle of the camshaft. When the top-pressing cylinder pushes the top-pressing slider to the right, the top right side wall of the top-pressing slider can exert a rightward pushing force on the left side wall of the right cam structure. The above is the overall structural setting of the axial top-pressing positioning mechanism of the camshaft, which is used to push the camshaft to the right along the axial direction and press it against the rotating chuck.
[0019] The left side wall of the rotary chuck is provided with a clamping and positioning mechanism, and an angular positioning mechanism for angular positioning of the head end of the camshaft. The clamping and positioning mechanism includes two symmetrically arranged positioning arms 12 that can form a clamping and enveloping effect on the circumferential surface of the head end of the camshaft. The two ends of the two positioning arms are provided with C-shaped grooves 13 that match the circumferential surface of the head end of the camshaft. The diameter of the semi-enclosed circle formed by the two C-shaped grooves matches the diameter of the head end of the camshaft, which is used to envelop and clamp the head end of the camshaft, but does not form a squeezing and clamping effect on the outer circumferential surface of the head end, so as not to cause the risk of squeezing and deformation of the camshaft. The angular positioning mechanism includes a positioning connecting seat 14 located between the two positioning arms. A central positioning post 15 for positioning the center hole 35 of the end face of the camshaft is fixedly provided in the middle of the positioning connecting seat. An eccentric positioning pin 16 for positioning the angular positioning groove 36 of the camshaft is provided on one side of the central positioning post. Specifically, the positioning fixture includes a fixed base plate 17 fixedly connected to the worktable. The head bracket and the tail bracket have the same structure, including an L-shaped positioning seat 18 locked to the fixed base plate, and a V-shaped support plate 19 connected above the L-shaped positioning seat. The upper end of the V-shaped support plate is provided with a V-shaped groove 20. The V-shaped grooves 20 of the head bracket and the tail bracket are respectively engaged between the two cam structures at the head end and the two cam structures at the tail end of the camshaft.
[0020] Specifically, the vertical sidewall of the L-shaped positioning seat has two vertically extending adjustment holes 21, and two adjustment screws 22 are inserted through the two adjustment holes respectively. The V-shaped support plate has corresponding locking screw holes 23, which are used to realize the up-and-down sliding adjustment of the V-shaped support plate on one side of the vertical sidewall of the L-shaped positioning seat, thereby realizing the overall support height adjustment of the head bracket and the tail bracket.
[0021] Specifically, a linear slide rail 24 extending in the left-right direction is fixedly laid on the horizontal side wall of the L-shaped mounting base, and a linear slider 25 is provided at the bottom of the top-pressing slider to enable the top-pressing slider to slide left and right along the upper surface of the horizontal side wall of the L-shaped mounting base under the action of the top-pressing cylinder.
[0022] Specifically, a pair of rolling support rollers 26 are symmetrically arranged on the inner sides of the two side walls of the V-shaped groove. The inner upper roller surfaces of the two support rollers are in rolling contact with the lower circumferential surface of the camshaft, changing sliding friction into rolling friction, reducing the friction between the circumferential surface of the camshaft and the V-shaped groove of the top pressing slider. When the camshaft is rotated for processing, the middle top pressing bracket plays the main supporting role for the camshaft, while the head bracket and tail bracket only play an auxiliary balancing support role.
[0023] Specifically, the top right side wall of the pressing slider is provided with a bullseye ball 27 that can roll in all directions. The top right side wall of the pressing slider pushes the left side wall of the right cam structure through the bullseye ball, changing the sliding friction into rolling friction, which is used to reduce the friction between the cam structure and the pressing slider.
[0024] Specifically, the bottom of the L-shaped positioning seat is locked to the fixed base plate via an adjusting base plate 28. The adjusting base plate, the L-shaped positioning seats of the head bracket and the tail bracket are all locked to the fixed base plate via connecting screws and U-shaped sliding nuts 29. The fixed base plate is provided with U-shaped transverse track grooves 30 that allow the sliding nuts to slide left and right. That is, the left and right positions of the head bracket, the tail bracket and the middle top pressure bracket on the worktable can be adjusted to adapt to the processing requirements of camshafts of different specifications.
[0025] It should be noted that the top lateral thickness of the V-shaped support plate of the head bracket and the tail bracket, as well as the top lateral thickness of the top pressing slider of the middle pressing bracket, are all less than the spacing between the two cam structures on the camshaft. This is to ensure that the camshaft has a certain amount of lateral movement allowance. Furthermore, the spacing allowance between the pressing slider and the cam structures on its left and right sides is less than the spacing allowance between the head bracket and the tail bracket and the camshafts on its left and right sides. This is to ensure that the pressing slider will not be interfered with by the head bracket and the tail bracket when it pushes the right cam structure to the right.
[0026] Specifically, a radially convex longitudinal track groove 31 is formed on the left side wall of the rotary chuck. Two convex locking nuts 32 are fitted into the longitudinal track groove. The two positioning arms are correspondingly locked to the rotary chuck by locking bolts and the two locking nuts. The circumferential distance between the two positioning arms can be adjusted by loosening the locking bolts, manually sliding the two positioning arms, and then locking them again to accommodate the head diameter of different camshafts. During adjustment, care should be taken to ensure that the center of the C-shaped groove of the two positioning arms is on the central axis of the camshaft.
[0027] Specifically, each of the four corners of the positioning connector is fixedly connected to the rotary chuck by a fixing bolt 33. The central positioning post and the eccentric positioning pin are integrally fixed to the positioning connector. A central hole is provided at the center of the end face of the camshaft head. The central positioning post is shaped like a frustum of a cone, which facilitates its insertion into the central hole. A semi-circular notch-shaped angular positioning groove is provided on the end face of the camshaft on one side of the central hole. The eccentric positioning pin is cylindrical and can be fitted into the angular positioning groove to prevent the camshaft from rotating in the circumferential direction, thereby achieving angular positioning during camshaft machining.
[0028] The working principle of this utility model is as follows: When clamping the camshaft to be processed onto the CNC machining center, first insert the head end of the camshaft into the two C-shaped slots between the two positioning arms of the rotary chuck in an inclined direction. At the same time, observe that the angular positioning slot of the camshaft is aligned with the eccentric positioning pin. Then, flatten the camshaft, and the eccentric positioning pin will just fit into the angular positioning slot, thus achieving angular positioning of the camshaft. The center positioning pin will just fit into the center hole of the camshaft, and the head bracket will just fit into the gap between the two cam structures at the head end of the camshaft, and the tail bracket will just fit into the gap between the two cam structures at the tail end of the camshaft. Then, control the top pressure cylinder to push the top pressure slider to the right to push against the cam structure on its right side, so that the entire camshaft is pressed to the right along the axial direction, further consolidating the tightness of the fit between the center hole of the camshaft and the center positioning pin, as well as the fit accuracy between the angular positioning slot of the camshaft and the eccentric positioning pin, thereby comprehensively achieving reliable positioning of the camshaft on the positioning fixture of the machining center.
[0029] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.
Claims
1. A camshaft angular positioning device for a CNC machining center, comprising a camshaft, a machining center, a worktable, and a cutting tool, wherein the worktable is provided with a rotary chuck for clamping the head end of the camshaft and a rotary ejector for pressing the tail end of the camshaft; the rotary chuck is rotatably connected to the upper right side of the worktable via a drive motor; the rotary ejector is rotatably connected to the upper left side of the worktable via a support base; a positioning fixture for clamping the camshaft is provided between the support base and the drive motor, characterized in that: The positioning fixture includes a head bracket and a tail bracket for cooperating with the head and tail ends of the camshaft, and a middle pressing bracket for supporting, lifting and axially positioning the camshaft. The central top-pressure bracket includes an L-shaped mounting base, a top-pressure slider, and a top-pressure cylinder. The L-shaped mounting base is fixedly connected to the top of the workbench. The top-pressure slider is slidably mounted on the upper right horizontal side wall of the L-shaped mounting base. The top-pressure cylinder is horizontally mounted on the left side of the vertical side wall of the L-shaped mounting base. The piston rod of the top-pressure cylinder passes through the vertical side wall of the L-shaped mounting base and connects to the top-pressure slider. The top of the top-pressure slider is provided with a V-shaped groove, which is engaged between the two cam structures in the middle of the camshaft. When the top-pressure cylinder pushes the top-pressure slider to the right, the top right side wall of the top-pressure slider can exert a rightward pushing force on the left side wall of the right cam structure. The left side wall of the rotary chuck is provided with a clamping and positioning mechanism, and an angular positioning mechanism for angular positioning of the head end of the camshaft. The clamping and positioning mechanism includes two symmetrically arranged positioning arms that can form a clamping and enveloping effect on the circumferential surface of the head end of the camshaft. The ends of the two positioning arms are provided with C-shaped grooves that match the circumferential surface of the head end of the camshaft. The angular positioning mechanism includes a positioning connecting seat located between the two positioning arms. A central positioning pin for positioning the center hole of the end face of the camshaft is fixedly provided in the middle of the positioning connecting seat. An eccentric positioning pin for positioning the angular positioning groove of the camshaft is provided on one side of the central positioning pin.
2. The camshaft angular positioning device for a CNC machining center according to claim 1, characterized in that: The positioning fixture includes a fixed base plate fixedly connected to the worktable. The head bracket and tail bracket have the same structure, including an L-shaped positioning seat locked to the fixed base plate and a V-shaped support plate connected above the L-shaped positioning seat. The upper end of the V-shaped support plate is provided with a second V-shaped slot. The second V-shaped slots of the head bracket and tail bracket are respectively engaged between the two cam structures at the head end and the two cam structures at the tail end of the camshaft.
3. The angular positioning device for a camshaft in a CNC machining center according to claim 2, characterized in that: The L-shaped positioning seat has two vertically extending adjustment holes on its vertical sidewall, and two adjustment screws are inserted through the two adjustment holes respectively. The V-shaped support plate has corresponding locking screw holes, which are used to realize the up-and-down sliding adjustment of the V-shaped support plate on one side of the vertical sidewall of the L-shaped positioning seat.
4. The angular positioning device for a camshaft in a CNC machining center according to claim 3, characterized in that: A linear slide rail extending in the left-right direction is fixedly laid on the horizontal side wall of the L-shaped mounting base, and a linear slider is provided at the bottom of the top pressure slider to realize the left-right sliding displacement of the top pressure slider on the horizontal side wall of the L-shaped mounting base.
5. The camshaft angular positioning device for a CNC machining center according to claim 4, characterized in that: A pair of rolling support rollers are symmetrically arranged on the inner sides of the two side walls of the V-shaped groove, and the inner upper roller surfaces of the two support rollers are in rolling contact with the lower circumferential surface of the camshaft.
6. The angular positioning device for a camshaft in a CNC machining center according to claim 5, characterized in that: The top right side wall of the pressing slider is provided with a bullseye ball that can roll in all directions. The top right side wall of the pressing slider pushes the left side wall of the right cam structure through the bullseye ball.
7. The camshaft angular positioning device for a CNC machining center according to claim 6, characterized in that: The bottom of the L-shaped positioning seat is lockingly connected to the fixed base plate via an adjusting base plate, and the adjusting base plate as well as the L-shaped positioning seats of the head support and the tail support are all lockingly connected to the fixed base plate via "convex"-shaped sliding nuts, and the fixed base plate is correspondingly provided with a "convex"-shaped transverse track groove that allows the sliding nuts to slide left and right for displacement.
8. The angular positioning device for a camshaft in a CNC machining center according to claim 1, characterized in that: A "convex"-shaped longitudinal track groove is radially opened on the left side wall of the rotating chuck, two "convex"-shaped locking nuts are fittingly arranged in the longitudinal track groove, and the two positioning clasping arms are correspondingly lockingly connected to the rotating chuck via locking bolts and the two locking nuts.
9. The angular positioning device for a camshaft in a CNC machining center according to claim 1, characterized in that: The four corners of the positioning connection seat are each fixedly connected to the rotating chuck via fixing bolts.