Cam, reciprocating driving mechanism, driving system and resetting method of driven part

Abstract

The invention belongs to the technical field of machining equipment, and discloses a cam, a reciprocating driving mechanism, a driving system and a reset method of a driven part. The cam comprises a cam body, wherein an annular groove is formed in the cam body; the inner ring side wall surface of the annular groove is a driving cam contour curved surface; the outer ring side wall surface of the annular groove is a reset cam contour curved surface; and the maximum stroke point of the profile curved surface of the driving cam and the minimum stroke point of the profile curved surface of the resetting cam are staggered. The reciprocating driving mechanism comprises a cam and further comprises a follower used for being connected with the driven part. And the follower is embedded into the annular groove and can slide along the contour curved surface of the whole driving cam when the follower is not clamped. Reciprocating motion can be driven through the driving cam contour curved surface, the clamping stagnation state can be automatically relieved through the reset cam contour curved surface, shutdown overhaul is avoided, the production cost is reduced, meanwhile, the rotating speed of a motor can be increased, the production takt is reduced, and therefore the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of processing equipment, and in particular relates to a resetting method of a cam, a reciprocating drive mechanism, a drive system and a driven member. Background Art

[0002] A cam is a component with a curved profile. In a cam push rod mechanism, the profile of the cam determines the lift and fall of the push rod. However, as an active component, the cam can only drive the push rod (follower) upward, and cannot drive the push rod downward to reset. Therefore, in the prior art, the restoring force of the reset spring is used to push the push rod downward to fit the profile of the cam to complete the reset of the push rod.

[0003] However, in some cases, the restoring force of the return spring is not enough to overcome the force that causes the push rod to get stuck. For example, in the moving knife drive system, after the moving knife cuts the material, the cutting debris causes the moving knife to get stuck. The moving knife cannot be reset simply by relying on the restoring force of the return spring. Once the moving knife gets stuck, the machine needs to be stopped to change the knife, which has a serious impact on production efficiency and production costs. Summary of the invention

[0004] In order to ensure smooth resetting of the follower, the present invention provides a cam, comprising:

[0005] A wheel body, wherein an annular groove is provided on the wheel body;

[0006] The inner ring side wall surface of the annular groove is an active cam profile curved surface;

[0007] The outer ring side wall surface of the annular groove is a reset cam profile curved surface;

[0008] The maximum stroke point of the active cam profile curved surface is staggered with the minimum stroke point of the reset cam profile curved surface.

[0009] In the present invention, the active cam profile surface is used to convert rotary motion into linear motion, and the reset cam profile surface is used to release the stuck state when the follower is stuck. The maximum stroke point and the minimum stroke point are staggered to ensure that the minimum stroke point is allowed to squeeze the follower wheel to release the stuck state only after the follower reaches the maximum stroke position.

[0010] Furthermore, the value range of the staggered angle α between the maximum travel point and the minimum travel point is 0°<α<360°, and the staggered angle refers to the angle between the lines connecting the rotation center to the maximum travel point and the minimum travel point respectively.

[0011] Furthermore, the staggered angle α between the maximum stroke point and the minimum stroke point is 90°. Under this staggered angle, the transition of the reset cam profile surface is smoother and more natural.

[0012] Further, the wheel body is disc-shaped and is applicable to linear reciprocating motion.

[0013] Further, a shaft hole is provided on the wheel body, and a keyway is formed on the pore wall of the shaft hole for achieving key connection.

[0014] Further, the wheel body is cylindrical and is applicable to reciprocating swing or linear reciprocating motion.

[0015] On the other hand, the present invention provides a reciprocating driving mechanism, which includes the cam of the present invention and also includes a follower for connecting a driven member;

[0016] The follower is embedded in the annular groove and can slide along the entire active cam contour surface when the driven member is not jammed;

[0017] The active cam contour surface is used for driving the follower to perform linear reciprocating motion when the driven member is subject to swing constraint;

[0018] The reset cam contour surface is used for squeezing the follower for resetting through the minimum stroke point when the driven member is jammed.

[0019] Further, the follower is a follower wheel, and the diameter of the follower wheel is smaller than the groove width at the narrowest part of the annular groove; and 0 < r b -r a < d, where d represents the diameter of the follower wheel, and r a represents the radial distance from the rotation center to the maximum stroke point of the active cam contour surface, and r b represents the radial distance from the rotation center to the minimum stroke point of the reset cam contour surface.

[0020] In the present invention, the diameter of the follower wheel is smaller than the groove width at the narrowest part of the annular groove, which enables the follower wheel to smoothly slide relative to the active cam contour surface in the annular groove to complete the forward stroke and return stroke of the driven member. When 0 < r b -r a < d is satisfied, it can be ensured that when the driven member is stuck at the maximum stroke position, the minimum stroke point of the reset cam contour surface contacts and squeezes the follower wheel.

[0021] Further, the axis of the follower wheel is parallel to the axis of the cam.

[0022] It is ensured that both the active cam contour surface and the reset cam contour surface can contact the arc surface of the follower wheel, and the contact between the turning point of the end face and the cylindrical surface of the follower wheel and the reset cam contour surface occurs, thereby reducing wear and prolonging the service life.

[0023] Furthermore, the follower wheel is a ball bearing, which has the advantages of small rolling resistance and high wear resistance, and can reduce the friction between the follower wheel and the active cam profile surface, thereby extending the service life.

[0024] Furthermore, a connecting rod extending outward from the annular groove is provided on the end surface of the follower, and is connected to a sliding portion of the linear guide mechanism through the connecting rod; the sliding portion is used to connect the follower.

[0025] After the follower is connected to the sliding part, the follower can move along the linear guide mechanism, and the movement is smoother.

[0026] Furthermore, the connecting rod is a threaded rod, and the connecting rod is threadedly connected to the sliding part. The threaded connection is convenient for installation and disassembly.

[0027] Furthermore, it also includes a reset mechanism fixedly connected to the sliding part, wherein the reset mechanism is perpendicular to the connecting rod and is used to keep the follower in contact with the active cam contour surface.

[0028] When the follower maintains contact with the active cam profile surface, the active cam profile surface can effectively act on the follower wheel.

[0029] On the other hand, the present invention also provides a driving system, comprising the reciprocating driving mechanism of the present invention, and also comprising a motor and a follower; the rotational motion of the motor is converted into the linear reciprocating motion of the follower wheel by the cam, and the follower wheel drives the follower to perform the linear reciprocating motion

[0030] Furthermore, the motor is a servo motor.

[0031] Furthermore, the driven member is a moving knife or a pin clamping module.

[0032] The present invention also provides a method for resetting a follower, comprising the following steps:

[0033] The driven member performs linear reciprocating motion under the action of the reciprocating drive mechanism of the present invention;

[0034] When the follower stays at the maximum stroke position due to jamming, as the cam continues to rotate, the follower wheel disengages from the maximum stroke point of the active cam profile surface and comes into contact with the minimum stroke point of the reset cam profile surface, and the reset cam profile surface squeezes the follower wheel to release the jammed state of the follower.

[0035] The cam of the present invention has two different contour surfaces at the same time, breaking through the limitation that the cam can only push the follower to move in one direction: the active cam contour surface is used to convert the rotary motion into linear motion, and the reset cam contour surface is used to release the stuck state when the follower is stuck. The reciprocating drive mechanism and drive system of the present invention can drive the follower to reciprocate normally through the cooperation of the cam and the follower wheel, and can automatically release the stuck state when the follower is stuck, avoiding shutdown for maintenance and reducing production costs. At the same time, it can allow the motor speed to increase, reduce the production cycle, and thus improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 It is a cam push rod mechanism in the prior art;

[0038] Figure 2 It is a cutting knife system in the prior art;

[0039] Figure 3 is a schematic diagram of the cam structure in the embodiment;

[0040] Figure 4 is a schematic diagram of the maximum travel point of the follower located on the contour surface of the active cam in Example 2;

[0041] Figure 5 This is a schematic diagram of the case where the follower in Embodiment 2 just contacts the minimum stroke point of the reset cam profile surface. DETAILED DESCRIPTION

[0042] refer to Figure 1 As shown, in the existing cam push rod mechanism, the profile curve of the cam 1-1 determines the lift and fall of the push rod 1-2. However, as an active member, the cam 1-1 can only drive the push rod 1-2 (the driven member) upward, and cannot drive the push rod 1-2 to reset downward. Therefore, in the prior art, the restoring force of the reset spring 1-3 is usually used to push the push rod 1-1 downward to fit the profile curve of the cam 1-1 to complete the reset of the push rod 1-2.

[0043] However, in some cases the restoring force of the return spring is not sufficient to overcome the force causing the push rod to stick.

[0044] refer to Figure 2As shown, in the pin wire cutting process, the cutting knife system is composed of a moving knife 2-2, a fixed knife 2-4 and a driving system 2-1. The driving system includes a driving motor, a cam push rod mechanism and a moving knife. The moving knife is connected to the push rod.

[0045] In the movable knife driving system 2-1, after the movable knife 2-2 cuts the pin wire 2-6, the pin wire 2-6 falls freely and stacks on the carrier 2-5, but the cutting debris often causes the movable knife 2-2 to get stuck, and the movable knife cannot be reset simply by the restoring force of the reset spring 2-3.

[0046] Considering the load and motion rigidity of the drive motor (acceleration and deceleration parameter design), only a reset spring with a smaller restoring force can be used to make the system drive more stable. Therefore, once the jamming force exceeds the restoring force, the cutter system will shut down, the product cannot be cut, and failure occurs. For the cutting of metal materials, such failure frequency is almost once every two days. After each failure, it is necessary to shut down, replace and clean the cutter, which takes 30 minutes per time. At the same time, in order to meet the recovery time of the reset spring, the speed of the drive motor needs to be reduced to meet the time interval for the spring recovery. It can be seen that once the moving knife is stuck, it is necessary to shut down and change the knife, which has a serious impact on production efficiency and production costs.

[0047] In order to ensure smooth resetting of the follower, the present invention provides a cam having two different contour surfaces at the same time, breaking through the limitation that the cam can only push the follower to move in one direction: the active cam contour surface is used to convert the rotary motion into linear motion, and the reset cam contour surface is used to release the stuck state when the follower is stuck.

[0048] Example 1

[0049] refer to Figure 3 As shown, this embodiment provides a cam, comprising:

[0050] A wheel body 1, wherein the wheel body 1 is provided with an annular groove 101;

[0051] The inner ring side wall surface of the annular groove 101 is an active cam profile curved surface 1011;

[0052] The outer ring side wall surface of the annular groove 101 is a reset cam profile curved surface 1012;

[0053] The maximum stroke point a of the active cam profile curved surface 1011 is staggered from the minimum stroke point b of the reset cam profile curved surface 1012 .

[0054] The active cam profile surface 1011 is used to convert rotary motion into linear motion, and the reset cam profile surface 1012 is used to release the jammed state when the follower gets jammed. The staggering of the maximum stroke point and the minimum stroke point ensures that after the follower reaches the maximum stroke position, the minimum stroke point is allowed to squeeze the follower wheel to release the jammed state.

[0055] The value range of the staggering angle α between the maximum stroke point and the minimum stroke point is 0° < α < 360°. The staggering angle refers to the included angle between the connecting lines from the center of rotation to the maximum stroke point and the minimum stroke point respectively.

[0056] Preferably, the staggering angle α between the maximum stroke point and the minimum stroke point is 90°. At this staggering angle, the reset cam profile surface 1012 has a smoother and more natural transition.

[0057] Preferably, the wheel body is disc-shaped. It is suitable for linear reciprocating motion.

[0058] Preferably, a shaft hole is also provided on the wheel body, and a keyway is provided on the hole wall of the shaft hole. It is used to achieve key connection.

[0059] Embodiment 2

[0060] Reference Figure 4 And Figure 5 As shown, this embodiment provides a reciprocating drive mechanism, which includes the cam of Embodiment 1, and also includes a follower 2 for connecting the follower 3;

[0061] The follower 2 is embedded in the annular groove 101 and can slide along the entire active cam profile surface 1011 when the follower 3 is not jammed;

[0062] The active cam profile surface 1011 is used to drive the follower 2 to perform linear reciprocating motion when the follower 3 is subject to swing constraints (such as using a frame 4 to constrain the follower 3 to limit the swing of the follower 3 and thus limit the swing of the follower 2);

[0063] The reset cam profile surface 1012 is used to reset the follower by squeezing the follower through the minimum stroke point when the follower gets jammed.

[0064] The shape of the follower 2 can be any shape. Preferably, the follower 2 is a circular follower wheel.

[0065] The diameter of the follower wheel is smaller than the groove width at the narrowest part of the annular groove; and 0 < r b -r a < d, where d represents the diameter of the follower wheel, and r a represents the radial distance from the center of rotation O to the maximum stroke point a of the active cam profile surface 1011, rb It represents the radial distance from the rotation center O to the minimum stroke point b of the reset cam profile surface 1012.

[0066] Reference Figure 4 With Figure 5 As shown, the diameter d of the follower wheel is smaller than the groove width at the narrowest part of the annular groove, which enables the follower wheel to smoothly slide relative to the active cam profile surface 1011 in the annular groove to complete the forward and return strokes of the follower. When 0 < r b -r a < d, it can be ensured that when the follower is stuck at the maximum stroke position, the minimum stroke point of the reset cam profile surface 1012 contacts and presses the follower wheel.

[0067] Preferably, the axis of the follower wheel is parallel to the axis of the cam.

[0068] Ensure that both the active cam profile surface 1011 and the reset cam profile surface 1012 can contact the arc surface of the follower wheel, and the turning point between the end face and the cylindrical surface of the follower wheel contacts the reset cam profile surface 1012, thereby reducing wear and extending the service life.

[0069] Preferably, the follower wheel is a ball bearing. The ball bearing has the advantages of small rolling resistance and high wear resistance, which can reduce the friction between the follower wheel and the active cam profile surface 1011 and extend the service life.

[0070] Preferably, a connecting rod extending out of the annular groove is provided on the end face of the follower 2, and the connecting rod is connected to the sliding part of the linear guiding mechanism; the sliding part is used to connect the follower. After the follower 2 is connected to the sliding part, the follower 2 can move along the linear guiding mechanism, and the movement is more stable.

[0071] In this embodiment, a linear guide rail is used as the linear guiding mechanism. The slide rail of the linear guide rail is fixed on the frame. The follower 2 is connected to the slider of the linear guide rail through a connecting rod, and the follower is connected to the slider. When the cam drives the follower 2 to move back and forth linearly, the follower can drive the follower to move back and forth linearly through the slide.

[0072] Preferably, the connecting rod is a threaded rod, and the connecting rod is threadedly connected to the sliding part. The threaded connection is convenient for installation and disassembly.

[0073] Preferably, a reset mechanism fixedly connected to the sliding part is further included. The reset mechanism is perpendicular to the connecting rod and is used to keep the follower 2 in contact with the active cam profile surface 1011. In addition, the function of the reset mechanism can also be realized by using the gravity of the follower and the follower 2, but due to the increase in weight, the load on the motor will increase.

[0074] In this embodiment, a mold spring is used as a reset mechanism, and the mold spring includes a housing, which is fixed on the sliding part of the linear guide mechanism. A hole for inserting the follower 2 is provided at the bottom of the housing, and a pressure rod is provided in the housing, one end of the pressure rod is fixedly connected to the top of the housing through a spring, and one end of the pressure rod is pressed against the follower 2 under the pressure of the spring.

[0075] When the follower 2 maintains contact with the active cam profile surface 1011 , the active cam profile surface 1011 can effectively act on the follower wheel.

[0076] Example 3

[0077] This embodiment provides a drive system, including the reciprocating drive mechanism of embodiment 2, and also including a motor and a follower; the rotational motion of the motor is converted into the linear reciprocating motion of the follower wheel by the cam, and the follower wheel drives the follower to perform linear reciprocating motion

[0078] In this embodiment, the motor is a servo motor.

[0079] In this embodiment, the driven member is a moving knife, thereby obtaining a moving knife drive system for cutting materials, such as cutting pin wires, copper tubes, etc.

[0080] A method for resetting a follower comprises the following steps:

[0081] The follower performs linear reciprocating motion under the action of the reciprocating drive mechanism.

[0082] When the follower stays at the maximum stroke position due to jamming, as the cam continues to rotate, the follower wheel disengages from the maximum stroke point of the active cam profile surface 1011 and comes into contact with the minimum stroke point of the reset cam profile surface 1012, and the reset cam profile surface 1012 squeezes the follower wheel to release the jammed state of the follower.

[0083] When the follower reaches the maximum stroke position, if there is no jamming, as the cam continues to rotate, the upward driving force of the cam on the follower is released, and the follower is reset by the reset mechanism, close to the active cam profile surface 1011.

[0084] Example 4

[0085] The difference between this embodiment and embodiment 3 is that the wheel body of the cam is cylindrical, the annular groove is arranged around the cylindrical surface, and the follower is a pin clamping module, thereby obtaining a pin drive system for inserting the pin into the connector.

[0086] Compared with the existing technology, the present invention has made great progress in efficiency and cost:

[0087] 1. Efficiency: The present invention can eliminate the jamming situation to the greatest extent. At the same time, since it no longer relies on the restoring force of the reset spring for reset, there is no need to wait for the recovery time of the spring, and the speed of the drive motor can be increased by 1.5 times, that is, the production cycle can be reduced by 30%.

[0088] 2. Cost: When a jam occurs, the cam automatically eliminates the jam state without the need to change the tool. Whether to replace the tool is no longer determined by the jam state, but by the state of the cutting edge of the material. After comprehensive evaluation, the tool life can be increased by 50% (based on field experience).

[0089] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. A cam, characterized in that: include: A wheel body, wherein an annular groove is provided on the wheel body; The inner ring side wall surface of the annular groove is an active cam profile curved surface; The outer ring side wall surface of the annular groove is a reset cam profile curved surface; The maximum stroke point of the active cam profile curved surface is staggered with the minimum stroke point of the reset cam profile curved surface.

2. The cam according to claim 1, characterized in that: The value range of the staggered angle α between the maximum travel point and the minimum travel point is 0°<α<360°, and the staggered angle refers to the angle between the lines connecting the rotation center to the maximum travel point and the minimum travel point respectively.

3. The cam according to claim 2, characterized in that: The offset angle between the maximum stroke point and the minimum stroke point is α=90°.

4. The cam according to claim 1, characterized in that: The wheel body is disc-shaped.

5. The reciprocating drive mechanism according to claim 4, characterized in that: The wheel body is also provided with an axial hole, and a key groove is opened on the hole wall of the axial hole.

6. The cam according to claim 1, characterized in that: The wheel body is cylindrical.

7. A reciprocating drive mechanism, characterized in that: A cam according to any one of claims 1 to 5, further comprising a follower for connecting to a follower; The follower is embedded in the annular groove and can slide along the entire active cam profile surface when the follower is not stuck; The active cam profile surface is used to drive the follower to perform linear reciprocating motion when the follower is subject to swing constraint; The reset cam profile surface is used to reset the follower by squeezing the follower through the minimum stroke point when the follower is stuck.

8. The reciprocating drive mechanism according to claim 7, characterized in that: The follower is a follower wheel, and the diameter of the follower wheel is smaller than the groove width at the narrowest part of the annular groove; and 0 < r b -r a < d, where d represents the diameter of the follower wheel, and r a represents the radial distance from the center of rotation to the maximum stroke point of the active cam profile surface, and r b represents the radial distance from the center of rotation to the minimum stroke point of the return cam profile surface.

9. The reciprocating drive mechanism according to claim 8, characterized in that: The axis of the follower wheel is parallel to the axis of the cam.

10. The reciprocating drive mechanism according to claim 7, characterized in that: The follower wheel is a ball bearing.

11. The reciprocating drive mechanism according to claim 7, characterized in that: A connecting rod extending outward from the annular groove is provided on the end surface of the follower, and is connected to the sliding part of the linear guide mechanism through the connecting rod; the sliding part is used to connect the follower.

12. The reciprocating drive mechanism according to claim 11, characterized in that: It also includes a reset mechanism fixedly connected to the sliding portion, the reset mechanism is perpendicular to the connecting rod and is used to keep the follower in contact with the active cam profile surface.

13. The reciprocating drive mechanism according to claim 11, characterized in that: The connecting rod is a threaded rod, and the connecting rod is threadedly connected to the sliding part.

14. A drive system, characterized in that: It includes the reciprocating drive mechanism as described in claim 7, and also includes a motor and a follower; the rotational motion of the motor is converted into the linear reciprocating motion of the follower wheel through the cam, and the follower wheel drives the follower to perform linear reciprocating motion.

15. The drive system according to claim 14, characterized in that: The motor is a servo motor.

16. The drive system according to claim 14, characterized in that: The driven part is a moving knife or a pin clamping module.

17. A method for resetting a follower, characterized in that: The following steps are involved: The driven member performs linear reciprocating motion under the action of the reciprocating drive mechanism as claimed in claim 14; When the follower stays at the maximum stroke position due to jamming, as the cam continues to rotate, the follower wheel disengages from the maximum stroke point of the active cam profile surface and comes into contact with the minimum stroke point of the reset cam profile surface, and the reset cam profile surface squeezes the follower wheel to release the jammed state of the follower.

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