A chip-breaking cam for a cam-type automatic lathe

Abstract

This utility model discloses a chip-breaking cam for a cam-type automatic lathe, relating to the field of transmission device technology. It includes a cam body, with a cam surface surrounding one end face edge for contacting a follower, and a mounting hole in the center for mounting a cam spindle. The cam surface includes a starting profile surface, a roughing profile surface, a transition profile surface, and a finishing profile surface that are smoothly connected sequentially in a clockwise direction. Multiple chip-breaking grooves are spaced clockwise on the roughing profile surface, and the cross-section of each groove is arc-shaped. This utility model enables the use of ordinary cutting tools while maintaining the machining parameters of the automatic lathe, achieving chip-breaking effects through a specially designed cam body structure, reducing machine setup difficulty, and improving machining efficiency.

Description

Technical Field

[0001] This utility model relates to the field of transmission device technology, and in particular to a chip-breaking cam for a cam-type automatic lathe used for processing soft material products. Background Technology

[0002] A cam-type automatic lathe is a lathe that uses a cam profile to control the movement of the cutting tool and the feeding mechanism to complete the machining of workpieces. It is mainly used for batch machining of small precision parts such as shafts and discs. When the cam-type automatic lathe is working, the cam rotates continuously at a constant speed around the cam spindle, transmitting the motion to the follower that is in close contact with the cam profile surface. The other end of the follower is connected to the outer diameter tool holder of the automatic lathe through a linkage mechanism. An outer diameter cutting tool is mounted on the tool holder. The rotating cam drives the follower to move through the profile surface. When the follower moves, it drives the outer diameter cutting tool on the tool holder to feed along the workpiece axis to perform cutting work through the linkage mechanism, or to retract along the workpiece axis away from the cutting position.

[0003] Currently, cam-type automatic lathes face the problem of ineffective chip breaking when machining highly ductile soft materials such as aluminum and mild steel. This leads to material entanglement, where the cut material fails to break into short fragments and instead forms continuous, long, thin chips. These chips become entangled on the lathe's cutting tool, workpiece, and even the machine tool's transmission components, causing a series of machining problems. Common solutions include using specialized cutting tools for soft materials and adjusting lathe machining parameters to achieve chip breaking. However, specialized cutting tools are expensive, and adjusting machining parameters is cumbersome and the chip breaking effect is not ideal. Therefore, it is necessary to provide a chip-breaking cam for cam-type automatic lathes used for machining soft material products. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a chip-breaking cam for a cam-type automatic lathe, which can achieve the chip-breaking effect by using ordinary cutting tools and a specially designed cam body structure while keeping the machining parameters of the automatic lathe unchanged, thereby reducing the difficulty of machine adjustment and improving machining efficiency.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A chip-breaking cam for a cam-type automatic lathe includes a cam body. One end face of the cam body is surrounded by a cam surface for contacting a follower. The middle part is provided with a mounting hole for mounting a cam spindle. The cam surface includes a starting profile surface, a roughing profile surface, a transition profile surface, and a finishing profile surface that are smoothly connected in a clockwise direction. Multiple chip-breaking grooves are provided at intervals in a clockwise direction on the roughing profile surface. The cross-section of the chip-breaking grooves is arc-shaped.

[0007] In some embodiments, the initial profile surface is a plane.

[0008] In some embodiments, the roughing profile surface includes a first rising surface, a first holding surface, and a first falling surface that are smoothly connected in a clockwise direction. The first rising surface rises progressively in a clockwise direction, and a plurality of chip breaking grooves are located on the surface of the first rising surface. The first holding surface is a plane, and the height of the first holding surface is higher than the starting profile surface. The first falling surface falls progressively in a clockwise direction.

[0009] In some embodiments, the transition profile surface is a plane, and the height of the transition profile surface is lower than the height of the first retaining surface.

[0010] In some embodiments, the precision machining profile surface includes a second rising surface, a second holding surface, a third rising surface, a third holding surface, and a second falling surface that are smoothly connected in a clockwise direction. The second rising surface and the third rising surface both rise progressively in a clockwise direction. The second holding surface and the third holding surface are planar, and the height of the second holding surface is higher than the height of the transition profile surface, the height of the third holding surface is higher than the height of the second holding surface, and the second falling surface falls progressively in a clockwise direction.

[0011] In some embodiments, a fixed sleeve is coaxially and integrally connected to one end of the cam body away from the cam surface. The sidewall of the fixed sleeve is surrounded by a plurality of screw holes, which penetrate the sidewall of the fixed sleeve radially.

[0012] In some embodiments, the follower is a drive pin, the axis of the follower is perpendicular to the axis of the cam body, and the follower is in close contact with the cam surface.

[0013] Compared with the prior art, this utility model achieves at least the following beneficial effects:

[0014] When the cam body rotates, it drives the follower to move through the cam surface. The follower then drives the linkage mechanism to move, which in turn drives the external cylindrical cutting tool on the tool holder to perform roughing and finishing operations on the product. By setting multiple chip-breaking grooves on the roughing profile, when the follower passes through the first chip-breaking groove, it loses the support of the cam surface and will have a rapid retraction action. That is, the follower drives the external cylindrical cutting tool to quickly retract along the product axis through the linkage mechanism. At this moment, the cutting action is suddenly interrupted. The chips that are forming on the product not only lose the cutting force support of the external cylindrical cutting tool, but also generate a reverse tensile or bending force due to the retraction of the external cylindrical cutting tool. Stress concentration is formed on the basis of work hardening due to plastic deformation in metal cutting. The originally continuous ribbon-like chips will break at the stress concentration point, avoiding the formation of long ribbon-like entanglement. This utility model can achieve the chip-breaking effect in machining by using ordinary tools and a specially designed cam body structure while keeping the machining parameters of the automatic lathe unchanged, solving the chip entanglement problem in the machining process, reducing the difficulty of machine adjustment, and improving machining efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of an embodiment of this application;

[0016] Figure 2 This is a side view of an embodiment of this application;

[0017] Figure 3 This is a schematic diagram of the structure installed on an automatic lathe according to an embodiment of this application;

[0018] Figure 4 This is an unfolded view of the cam body according to an embodiment of this application;

[0019] Figure 5 This is a structural diagram of the processed soft material product.

[0020] The following are the labels in the diagram: 1. Cam body; 2. Mounting hole; 3. Cam spindle; 4. Starting profile surface; 5. Roughing profile surface; 51. First rising surface; 52. First holding surface; 53. First falling surface; 6. Transition profile surface; 7. Finishing profile surface; 71. Second rising surface; 72. Second holding surface; 73. Third rising surface; 74. Third holding surface; 75. Second falling surface; 8. Chip breaking groove; 9. Fixing sleeve; 91. Screw hole; 10. Follower. Detailed Implementation

[0021] The present invention will now be described in detail with reference to exemplary embodiments shown in the accompanying drawings. However, it should be understood that the present application may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided herein to make the disclosure of this application more complete and to fully convey the concept of the present application to those skilled in the art.

[0022] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "several" or "more than" means two or more, unless otherwise explicitly specified. In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In this application, unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. Moreover, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] like Figures 1-4As shown in the embodiment of this application, the chip-breaking cam of the cam-type automatic lathe includes a cam body 1. One end face of the cam body 1 is surrounded by a cam surface for contacting the follower 10, and the middle is provided with a mounting hole 2 for mounting the cam spindle 3. The cam surface includes a starting profile surface 4, a roughing profile surface 5, a transition profile surface 6, and a finishing profile surface 7 that are smoothly connected in a clockwise direction. The roughing profile surface 5 is provided with a plurality of chip-breaking grooves 8 spaced in a clockwise direction, and the cross-section of the chip-breaking grooves 8 is arc-shaped. Before turning the product, the cam body 1 is installed in the correct direction to the position of the follower 10 corresponding to the cam spindle 3, and the cam body 1 is locked. In this example, the follower 10 is a drive pin. The axis of the follower 10 is perpendicular to the axis of the cam body 1, and in the initial state, the outer circular surface of the follower 10 is in close contact with the starting profile surface 4 of the cam body 1, and the outer circular surface of the follower 10 is in sliding contact with the cam surface.

[0024] In processing such as Figure 5 When processing soft material products, the automatic lathe operates, and the cam spindle 3 drives multiple cams to rotate together. Each rotation of the chip-breaking cam completes the turning of one product. The follower 10 is connected to the automatic lathe's outer diameter tool holder via a linkage mechanism. The connection between the follower 10 (transmission pin) and the automatic lathe's outer diameter tool holder via the linkage mechanism is existing technology and will not be elaborated upon here. When the cam body 1 of the chip-breaking cam rotates, it drives the follower 10 to move via the cam surface. The follower 10 then drives the linkage mechanism to move. During this movement, the linkage mechanism drives the external cylindrical cutting tool on the tool holder to perform roughing and finishing operations on the product. During roughing or finishing, the external cylindrical cutting tool feeds along the workpiece axis to cut the outer cylindrical surface of the product, removing excess material (chips). After cutting, it retracts along the workpiece axis, leaving the cutting position.

[0025] Specifically, the initial profile surface 4 is a plane. The roughing profile surface 5 includes a first rising surface 51, a first holding surface 52, and a first falling surface 53 that are smoothly connected in a clockwise direction. The first rising surface 51 rises progressively in a clockwise direction, and multiple chip-breaking grooves 8 are located on the surface of the first rising surface 51. In this example, there are 8 chip-breaking grooves 8. This application does not limit the specific number of chip-breaking grooves 8, and it can be set according to actual processing requirements. The first holding surface 52 is a plane, and the height of the first holding surface 52 is higher than that of the initial profile surface 4. The first falling surface 53 falls progressively in a clockwise direction. The transition profile surface 6 is a plane, and the height of the transition profile surface 6 is lower than that of the first holding surface 52. The precision-machined profile surface 7 includes a second rising surface 71, a second holding surface 72, a third rising surface 73, a third holding surface 74, and a second falling surface 75 that are smoothly connected in a clockwise direction. The second rising surface 71 and the third rising surface 73 both rise gradually in a clockwise direction. The second holding surface 72 and the third holding surface 74 are planar, and the height of the second holding surface 72 is higher than the height of the transition profile surface 6. The height of the third holding surface 74 is higher than the height of the second holding surface 72. The second falling surface 75 falls gradually in a clockwise direction.

[0026] When rough turning the outer cylindrical surface of a workpiece on an automatic lathe, the specific steps are as follows: ① From the initial contour surface 4 to the area of ​​the first rising surface 51, the cam body 1 drives the follower 10 to gradually rise. At this time, the follower 10 drives the external cylindrical cutting tool to feed along the workpiece axis through the linkage mechanism. Since there are multiple chip breaking grooves 8 distributed on the first rising surface 51, when the follower 10 passes through the first chip breaking groove 8 in the area of ​​the first rising surface 51, it loses the support of the cam surface. The follower 10 will have a rapid fall action, that is, the follower 10 drives the external cylindrical cutting tool to quickly retract along the workpiece axis through the linkage mechanism. At this moment, the cutting action is suddenly interrupted, and the chips that are being formed on the product not only lose their outer diameter but also... The cutting force of the circular cutting tool is supported by the reverse tensile or bending force generated by the retraction of the external circular cutting tool. Stress concentration is formed on the basis of work hardening due to plastic deformation in metal cutting. The originally continuous strip of chips will break at the stress concentration point, avoiding the formation of long strips of tangled material. Moreover, the position and size of multiple chip breaking grooves 8 are precisely designed according to the processing requirements. When the cam body 1 rotates, the follower 10 will break a chip every time it passes through the chip breaking groove 8. The chips can be precisely controlled within a fixed short length range. These short chips will not wrap around the tool, workpiece or spindle. The short chips will be easily removed from the processing area by the flushing of the cutting fluid and the airflow, achieving smooth chip removal. When the cam body 1 drives the follower 10 to rise again, and the height exceeds the previous high point, the external turning tool will re-enter the cutting operation. This cycle repeats multiple times until the follower 10 moves to the area of ​​the first holding surface 52. Since the first holding surface 52 is a plane, the follower 10 does not move and therefore no longer drives the external turning tool to perform feed motion, and the external turning tool stops cutting. ② When the follower 10 moves to the end point of the area of ​​the first holding surface 52, it gradually descends from the area of ​​the first descending surface 53 to the area of ​​the transition contour surface 6. Then the external turning tool returns from the cutting position to the original starting position, completing the rough turning of the workpiece's outer diameter.

[0027] When precision turning the outer cylindrical surface of a workpiece on an automatic lathe, the specific steps are as follows: ① From the transition contour surface 6 region to the second rising surface 71 region, the cam body 1 drives the follower 10 to gradually rise along the second rising surface 71. The displacement of the follower 10 drives the external cylindrical cutting tool on the tool holder to perform feed motion, performing precision turning of the outer cylindrical surface of the product until the follower 10 enters the second holding surface 72. Since the second holding surface 72 is a plane, the follower 10 does not move, and the external cylindrical cutting tool stops cutting; ② From the second holding surface 72 region to the third rising surface 73 region, the cam body 1 continues to drive... The follower 10 gradually rises along the third rising surface 73. The displacement of the follower 10 drives the external cylindrical cutting tool on the tool holder to perform feed motion, and performs precision turning on the other outer cylindrical surface of the soft material product until the follower 10 enters the area of ​​the third holding surface 74 and stops cutting; ③ When the follower 10 moves to the end point of the area of ​​the third holding surface 74, it gradually descends from the area of ​​the second falling surface 75 back to the end position. The end position and the starting position of the starting contour surface 4 form a closed loop. Then the external cylindrical cutting tool retracts from the cutting position to the starting position, thus completing the entire precision turning action of the workpiece's outer cylindrical surface.

[0028] A fixed sleeve 9 is coaxially and integrally connected to one end of the cam body 1 away from the cam surface. The side wall of the fixed sleeve 9 is provided with multiple screw holes 91, and each screw hole 91 penetrates the side wall of the fixed sleeve 9 radially. By providing screw holes 91, it is convenient to use screws to lock the cam body 1 onto the cam spindle 3.

[0029] It should be understood that all the above embodiments are exemplary and not restrictive. Any modifications, equivalent changes and alterations made by those skilled in the art to the specific embodiments described above under the concept of this utility model shall still fall within the scope of the technical solution of this utility model.

Claims

1. A chip-breaking cam for a cam-type automatic lathe, comprising a cam body, wherein one end face of the cam body is surrounded by a cam surface for contacting a follower, and a mounting hole is provided in the middle for mounting a cam spindle, characterized in that: The cam surface includes a starting profile surface, a roughing profile surface, a transition profile surface, and a finishing profile surface that are smoothly connected in a clockwise direction. The roughing profile surface has multiple chip-breaking grooves spaced at intervals in a clockwise direction, and the cross-section of the chip-breaking grooves is arc-shaped.

2. The chip-breaking cam of the cam-type automatic lathe according to claim 1, characterized in that: The initial contour surface is a plane.

3. The chip-breaking cam of the cam-type automatic lathe according to claim 2, characterized in that: The roughing profile surface includes a first rising surface, a first holding surface, and a first falling surface that are smoothly connected in a clockwise direction. The first rising surface rises progressively in a clockwise direction, and a plurality of chip-breaking grooves are located on the surface of the first rising surface. The first holding surface is a plane, and the height of the first holding surface is higher than the starting profile surface. The first falling surface falls progressively in a clockwise direction.

4. The chip-breaking cam of the cam-type automatic lathe according to claim 3, characterized in that: The transition profile surface is a plane, and the height of the transition profile surface is lower than the height of the first holding surface.

5. The chip-breaking cam of the cam-type automatic lathe according to claim 4, characterized in that: The precision machining profile includes a second rising surface, a second holding surface, a third rising surface, a third holding surface, and a second falling surface that are smoothly connected in a clockwise direction. The second rising surface and the third rising surface both rise gradually in a clockwise direction. The second holding surface and the third holding surface are planar, and the height of the second holding surface is higher than the height of the transition profile surface, the height of the third holding surface is higher than the height of the second holding surface, and the second falling surface falls gradually in a clockwise direction.

6. The chip-breaking cam of the cam-type automatic lathe according to claim 1, characterized in that: A fixed sleeve is coaxially and integrally connected to one end of the cam body away from the cam surface. The side wall of the fixed sleeve is surrounded by multiple screw holes, which penetrate the side wall of the fixed sleeve radially.

7. The chip-breaking cam of the cam-type automatic lathe according to claim 1, characterized in that: The follower is a transmission pin, the axis of which is perpendicular to the axis of the cam body, and the follower is in close contact with the cam surface.

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