A laser cladding device with a wide range of adjustable duty cycles

Abstract

The present invention discloses a laser cladding device with a wide range of adjustable duty cycle, comprising a parabolic focusing mirror, a first conical mirror, a second conical mirror and a powder spraying device. The parabolic focusing mirror and the second conical mirror are both annular, and the reflection surfaces of the first conical mirror and the second conical mirror are opposite to the reflection surface of the parabolic focusing mirror, so that the light beam incident on the first conical mirror and the second conical mirror from the central axis of the parabolic focusing mirror is reflected toward the circumference by the reflection surfaces of the two and incident on the reflection surface of the parabolic focusing mirror, and is further reflected and focused by the reflection surface of the parabolic focusing mirror. The position of the second conical mirror is fixed, the first conical mirror can be moved along the central axis of the parabolic focusing mirror, and the powder spraying device is arranged below the second conical mirror. The laser cladding device with a wide range of adjustable duty cycle of the present invention can change the duty cycle without changing the outer diameter of the annular light beam, and the adjustment range of the duty cycle is large.

Description

Technical Field

[0001] The invention relates to the field of additive manufacturing, and in particular to a laser cladding device with a wide range of adjustable duty cycles. Background Art

[0002] As an advanced surface coating preparation technology, laser cladding has achieved rapid development in recent years. The traditional annular laser cladding device adjusts the mirror group to shape the solid spot into an annular spot. At the same time, each laser beam has the same optical focus and converges into a solid point spot at this position.

[0003] The duty cycle is a geometric parameter of the annular laser beam, which has a significant impact on the microstructure of metal materials after cladding. The material structure is different at different duty cycle values. Through research, it is found that the expected microstructure can be obtained by changing the duty cycle of the annular laser beam, and a large number of experiments have shown that the microstructure control effect when the duty cycle is between 0 and 0.5 is more ideal and obvious.

[0004] At present, the conventional method of changing the duty cycle of the laser beam is to obtain different duty cycle values ​​by changing the defocus amount. However, this method will change other parameters while obtaining different duty cycles. For example, after changing the defocus amount, while obtaining a new duty cycle, the inner and outer diameters of the spot will change significantly. The change in outer diameter will affect the change in the width of the single cladding channel (melt width). Therefore, it is impossible to explore the impact of different duty cycles while ensuring a certain melt width. At the same time, because the defocus amount is changed, it is impossible to determine the extent of the influence of the duty cycle itself on the laser cladding process. Summary of the invention

[0005] The purpose of the present invention is to provide a laser cladding device with a wide range of adjustable duty cycle, which can change the duty cycle without changing the outer diameter of the annular spot, and the adjustment range of the duty cycle is relatively large.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A laser cladding device with a wide range of adjustable duty cycle, comprising a parabolic focusing mirror, a first axle, a second axle and a powder spraying device, wherein the parabolic focusing mirror and the second axle are both annular, and the reflection surfaces of the first axle and the second axle are opposite to the reflection surface of the parabolic focusing mirror, so that a light beam incident on the first axle and the second axle from the central axis of the parabolic focusing mirror is reflected toward the circumference by the reflection surfaces of the two and incident on the reflection surface of the parabolic focusing mirror, and is further reflected and focused by the reflection surface of the parabolic focusing mirror;

[0008] The position of the second conical mirror is fixed, the first conical mirror can be moved along the central axis of the parabolic focusing mirror, the powder spraying device is arranged below the second conical mirror, and the reflecting surface of the parabolic focusing mirror makes the focus of the light form a ring line around the central axis of the parabolic focusing mirror.

[0009] Optionally, the focus of the light reflected by the parabolic focusing mirror is located on an optical focal plane, and there is a preset plane on the optical focal plane close to the parabolic focusing mirror, and the light reflected from the parabolic focusing mirror forms a solid light spot on the preset plane.

[0010] Optionally, the focus of the light reflected by the parabolic focusing mirror is located on an optical focal plane, and a working plane is selected on a side of the optical focal plane close to the parabolic focusing mirror, and the defocus amount of the working plane satisfies:

[0011] ;

[0012] Among them, F represents the defocus amount of the working plane, D represents the diameter of the ring formed by the focus of the light reflected by the parabolic focusing mirror, and θ3 represents the angle between the outgoing light path at the lower limit position of the first conical mirror and the central axis.

[0013] Optionally, the duty cycle adjustment range of the light reflected by the parabolic focusing mirror in the selected working plane is:

[0014] ;

[0015] Among them, K represents the duty cycle of the light reflected by the parabolic focusing mirror in the selected working plane, θ2 represents the angle between the output light path at the upper limit position of the first conical mirror and the central axis, and θ represents the angle between the output light path of the second conical mirror and the central axis.

[0016] Optionally, an inner diameter of the second axle is smaller than or equal to a diameter of the first axle.

[0017] Optionally, it also includes a mirror seat and a motion adjustment member, the mirror seat includes a first annular fixing portion, the second conical mirror is fixed to the first annular fixing portion, the motion adjustment member is passed through the first annular fixing portion and drives the first conical mirror to move along the central axis of the parabolic focusing mirror, the first conical mirror is fixed to the top end of the motion adjustment member, and the powder spraying device is fixed to the bottom end of the motion adjustment member.

[0018] Optionally, the mirror mount also includes a connecting portion for fixing the first annular fixing portion, the motion adjustment member is a lifting bolt, the connecting portion is provided with a channel extending through the first annular fixing portion, an adjusting bolt is provided in the channel, and the first annular fixing portion is provided with a multi-stage bevel gear for transmission connecting the adjusting bolt and the lifting bolt.

[0019] Optionally, the mirror seat further includes a second annular fixing portion, the parabolic focusing mirror is fixed to the second annular fixing portion, the second annular fixing portion is located on the outer periphery of the first annular fixing portion, and the two are connected by the connecting portion.

[0020] Optionally, a water cooling space for absorbing heat accumulated in the first conical mirror is provided inside the lifting bolt and the first conical mirror, and a cooling space is provided inside the parabolic focusing mirror.

[0021] Optionally, it also includes a device housing, which cooperates with the mirror base to encapsulate the parabolic focusing mirror.

[0022] It can be seen from the above technical scheme that the laser cladding device with a wide range of adjustable duty cycle provided by the present invention includes a parabolic focusing mirror, a first conical mirror, a second conical mirror and a powder spraying device, the parabolic focusing mirror and the second conical mirror are both annular, and the reflection surfaces of the first conical mirror and the second conical mirror are opposite to the reflection surface of the parabolic focusing mirror, so that the light beam incident on the first conical mirror and the second conical mirror from the central axis of the parabolic focusing mirror is reflected by the reflection surfaces of the two mirrors toward the circumference and incident on the reflection surface of the parabolic focusing mirror, and is further reflected and focused by the reflection surface of the parabolic focusing mirror. Among them, the position of the second conical mirror is fixed, the first conical mirror can move along the central axis of the parabolic focusing mirror, and the powder spraying device is arranged below the second conical mirror.

[0023] After the outgoing light beam is focused by the parabolic focusing mirror, there is a section of annular light beam, and the light reflected by the second axle mirror forms the outer light of the section of annular light beam, and the light reflected by the first axle mirror forms the inner light of the section of annular light beam. Therefore, the position of the second axle mirror is fixed, and when the first axle mirror is moved along the central axis of the parabolic focusing mirror, the outer diameter of the section of annular light beam remains unchanged, and the inner diameter of the section of annular light beam changes as the first axle mirror moves along the central axis of the parabolic focusing mirror, so as to adjust the duty cycle of the section of the outgoing light beam, and change the duty cycle without changing the outer diameter of the annular light beam. In addition, the reflective surface of the parabolic focusing mirror makes the focus of the light beam form a ring line around the central axis of the parabolic focusing mirror, so that the focus of the light reflected by the parabolic focusing mirror deviates from the central axis of the parabolic focusing mirror, which can greatly reduce the inner diameter of the section of the annular light beam of the outgoing light beam, and reduce the outer diameter of the section of the annular light beam to a smaller extent, so that the adjustment range of the duty cycle of the section of the annular light beam can be increased. Therefore, the laser cladding device with a wide range of adjustable duty cycle of the present invention can change the duty cycle without changing the outer diameter of the annular light beam, and the adjustment range of the duty cycle is relatively large. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A schematic diagram of the optical path of an outgoing light beam of a laser cladding device with a wide range of adjustable duty cycle according to an embodiment of the present invention;

[0026] Figure 2 for Figure 1 Schematic diagram of the change of the duty cycle of the outgoing light beam at each defocus plane;

[0027] Figure 3 A schematic diagram of the optical path of the outgoing light beam with the focus on the central axis of the parabolic focusing mirror and a schematic diagram of the change of the duty cycle at each defocus plane;

[0028] Figure 4 A longitudinal cross-sectional view of a laser cladding device with a wide range of adjustable duty cycles provided by an embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of the duty cycle change of the laser cladding device in the selected working plane according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0031] This embodiment provides a laser cladding device with a wide range of adjustable duty cycle, including a parabolic focusing mirror, a first cone mirror, a second cone mirror and a powder spraying device.

[0032] The parabolic focusing mirror and the second axicon are both annular, and the reflection surfaces of the first axicon and the second axicon are opposite to the reflection surface of the parabolic focusing mirror, so that the light beam incident on the first axicon and the second axicon from the central axis of the parabolic focusing mirror is reflected toward the circumference by the reflection surfaces of the two axicon and incident on the reflection surface of the parabolic focusing mirror, and is further reflected and focused by the reflection surface of the parabolic focusing mirror;

[0033] The position of the second conical mirror is fixed, the first conical mirror can be moved along the central axis of the parabolic focusing mirror, the powder spraying device is arranged below the second conical mirror, and the reflecting surface of the parabolic focusing mirror makes the focus of the light form a ring line around the central axis of the parabolic focusing mirror.

[0034] The light beam is incident from the central axis of the parabolic focusing mirror to the first axicon and the second axicon, and is reflected by the reflection surfaces of the two and emitted toward the circumference. The reflected light beam is incident on the reflection surface of the parabolic focusing mirror, and is reflected and focused by the reflection surface of the parabolic focusing mirror. The light beam reflected by the reflection surface of the parabolic focusing mirror is focused to form a loop around the central axis of the parabolic focusing mirror. A loop refers to a closed curve.

[0035] After the outgoing light beam is focused by the parabolic focusing mirror, there is a section of annular light beam, and the light reflected by the second axle mirror forms the outer light beam of the section of annular light beam, and the light reflected by the first axle mirror forms the inner light beam of the section of annular light beam. Since the position of the second axle mirror is fixed, when the first axle mirror is moved along the central axis of the parabolic focusing mirror, the outer diameter of the section of annular light beam remains unchanged, and the inner diameter of the section of annular light beam changes as the first axle mirror moves along the central axis of the parabolic focusing mirror. In this way, the duty cycle of the section of the outgoing light beam is adjusted, and the duty cycle is changed without changing the outer diameter of the annular light beam.

[0036] In addition, in the present device, the reflective surface of the parabolic focusing mirror makes the focus of the light form a ring line around the central axis of the parabolic focusing mirror, so that the focus of the light reflected by the parabolic focusing mirror deviates from the central axis of the parabolic focusing mirror, which can greatly reduce the inner diameter of the segment of the annular beam of the outgoing light beam, and reduce the outer diameter of the segment of the annular beam to a smaller extent, so that the duty cycle of the segment of the annular beam can be increased. Therefore, the laser cladding device with a wide range of adjustable duty cycle of the present embodiment can change the duty cycle without changing the outer diameter of the annular beam, and the duty cycle has a large adjustment range.

[0037] The focus of the light reflected by the parabolic focusing mirror is located on the optical focal plane, and the light reflected by the parabolic focusing mirror is focused on the optical focal plane and the focus of each part of the light forms a ring line. For example, please refer to Figure 1 and Figure 2 , Figure 1 Schematic diagram of the optical path of the outgoing light beam of the laser cladding device with a wide range of adjustable duty cycle in this embodiment. Figure 2 for Figure 1 The schematic diagram of the change of the duty cycle of the outgoing light beam at each defocus plane is shown in FIG. Figure 1 and Figure 2 Shown is the Figure 4 The change process of beam duty cycle in area A. Combined with reference Figure 1 and Figure 2As shown, the e-plane is the optical focal plane, the optical focus of the parabolic focusing mirror is located on the e-plane, the outgoing light beam is focused on the e-plane, and the outgoing light beam is in a ring shape on the e-plane.

[0038] More specifically, there is a preset plane on the side of the optical focal plane close to the parabolic focusing mirror, and the light reflected by the parabolic focusing mirror forms a solid light spot on the preset plane. Figure 1 and Figure 2 , there is a c-plane above the e-plane, and the outgoing light beam forms a solid spot on the c-plane, which is formed by the cross-overlapping parts of the outgoing light beam. This spot can be considered as the geometric focus of the outgoing light beam, and its duty cycle can be regarded as 1, and its duty cycle value cannot be changed by changing the position of the first conic mirror.

[0039] The d plane below the c plane is a positive defocusing plane. When the first conical mirror is moved along the central axis of the parabolic focusing mirror, the inner diameter of the light spot of the outgoing light beam on the d plane of the positive defocusing plane remains unchanged, while the outer diameter changes.

[0040] The a plane and the b plane above the c plane are negative defocus planes. This laser cladding device selects the negative defocus plane as the working plane for laser cladding. Figure 2 , Figure 2 The two columns of light spots on the right side are the light spots when the first conical mirror is in the upper limit position and the light spots when the first conical mirror is in the lower limit position. As shown in the figure, when the first conical mirror is in the upper limit position, the inner diameter of the light spot on plane a is very small, and the inner diameter of the light spot on plane b is very small. For plane a, the inner diameter of the light spot on plane a changes greatly when the first conical mirror is in the upper limit position compared to when it is in the lower limit position; similarly, for plane b, the inner diameter of the light spot on plane b changes greatly when the first conical mirror is in the upper limit position compared to when it is in the lower limit position. By moving the first conical mirror between the upper limit position and the lower limit position, the light spot can be changed between the two limit sizes, and the duty cycle can be changed within a certain range.

[0041] For example, reference may be made to Figure 3 , Figure 3 The figure is a schematic diagram of the optical path of the outgoing light beam with the focus on the central axis of the parabolic focusing mirror and a schematic diagram of the change of the duty cycle at each defocus plane. In the figure, a and b are negative defocus working planes, c is the focus plane, and d is the positive defocus working plane. It can be clearly seen that Figure 3 Shown with Figure 1 and Figure 2 Compared with the above, without changing the incident angle of the optical path and other optical structures, Figure 1 and Figure 2 The laser cladding device of the present embodiment shown has a larger adjustment range of the spot size and duty cycle of the output light beam at different defocus amounts.

[0042] For example, please refer to Figure 4 , Figure 4 A longitudinal cross-sectional view of a laser cladding device with a wide range of adjustable duty ratio provided in this embodiment, as shown in the figure, the parabolic focusing mirror 103 and the second axle 102 are annular, and the reflection surfaces of the first axle 101 and the second axle 102 are opposite to the reflection surface of the parabolic focusing mirror 103. The position of the second axle 102 is fixed, and the first axle 101 can move along the central axis of the parabolic focusing mirror 103.

[0043] In the figure, the first axicon 101 indicated by the dotted line indicates the upper limit position of the first axicon 101, and the dotted line light represents the light propagation path of the first axicon 101 when it is in the upper limit position. The first axicon 101 indicated by the solid line indicates the lower limit position of the first axicon 101, and the corresponding solid line light represents the light propagation path of the first axicon 101 when it is in the lower limit position. The solid line light corresponding to the second axicon 102 represents the light propagation path of the second axicon 102.

[0044] Specifically, the inner diameter of the second axle 102 is less than or equal to the diameter of the first axle 101. For example, if the light beam is incident vertically, if the inner diameter of the second axle 102 is greater than the diameter of the first axle 101, the incident solid circular light beam will not be able to completely fall on the two axle oblique mirror surfaces (i.e., the reflection surfaces of the two axles), and the light beam will irradiate other parts, causing the parts to be damaged due to direct exposure to the laser beam, and it can also avoid affecting the size of the final emitted light beam. The first axle 101 can move up and down along the central axis of the parabolic focusing mirror 103. Preferably, when the first axle 101 is in the upper limit position, the top of the first axle 101 is not higher than the top of the reflection surface of the parabolic focusing mirror 103, so as to avoid that when the top of the first axle 101 is higher than the top of the reflection surface of the parabolic focusing mirror 103, the light beam will be split by the first axle 101 and will be directed to the parts above the parabolic focusing mirror 103, and the parts above do not have the ability to reflect light. When the first conical mirror 101 is at the lower limit position, the bottom end of the first conical mirror 101 is not lower than the top end of the second conical mirror 102. If the bottom end of the first conical mirror 101 is lower than the top end of the second conical mirror 102 at this time, the light separated by the first conical mirror 101 will be projected into the inner wall of the second conical mirror 102 and blocked, which will not only affect the final light beam size but also damage the second conical mirror 102.

[0045] Among them, the reflecting surface of the parabolic focusing mirror 103 satisfies the optical path corresponding to the first cone mirror 101 being in the upper limit position and the optical path corresponding to the lower limit position. Both optical paths maintain a certain safety distance from the powder spraying device 104, and the light reflected by the first cone mirror 101 when it is in the upper limit position cannot be incident on the second cone mirror 102 again.

[0046] Furthermore, the device of this embodiment may also include a mirror seat and a motion adjustment member, the mirror seat includes a first annular fixing portion, the second cone mirror is fixed to the first annular fixing portion, the motion adjustment member is inserted into the first annular fixing portion and drives the first cone mirror to move along the central axis of the parabolic focusing mirror, the first cone mirror is fixed to the top of the motion adjustment member, and the powder spraying device is fixed to the bottom of the motion adjustment member. In this embodiment, the method of driving the motion adjustment member to move to drive the first cone mirror 101 to move is not limited. Optionally, in some embodiments, the mirror seat may also include a connecting portion for fixing the first annular fixing portion, the motion adjustment member is a lifting bolt, the connecting portion is provided with a channel passing through the first annular fixing portion, the channel is provided with an adjustment bolt, and the first annular fixing portion is provided with a multi-stage bevel gear that drives the adjustment bolt and the lifting bolt. By rotating the adjustment bolt, the multi-stage bevel gear is driven to rotate, and then the lifting bolt is driven to drive the first cone mirror at its top to move.

[0047] For example, please refer to Figure 4 As shown, the second conical mirror 102 is fixed to the first annular fixing portion 105, the motion adjustment member 106 is inserted through the first annular fixing portion 105, the first conical mirror 101 is fixed to the top of the motion adjustment member 106, and the powder spraying device 104 is fixed to the bottom of the motion adjustment member 106. The adjusting bolt 107 is inserted into the channel of the connecting portion (not shown in the figure), and the adjusting bolt 107 and the lifting bolt are connected by transmission through the multi-stage gear 108. By rotating the adjusting bolt, the multi-stage bevel gear is driven to rotate, and then the lifting bolt is driven to drive the first conical mirror at its top to move, so as to drive the first conical mirror 101 to move up and down along the central axis of the parabolic focusing mirror 103.

[0048] Furthermore, the mirror base may further include a second annular fixing portion, the parabolic focusing mirror is fixed to the second annular fixing portion, the second annular fixing portion is located at the outer periphery of the first annular fixing portion, and the two are connected by the connecting portion. Figure 4 As shown, the parabolic focusing mirror 103 is fixed to the second annular fixing portion 109. Specifically, a channel is provided in the second annular fixing portion 109, the channel is communicated with the channel of the connecting portion, and the adjusting bolt 107 is passed through the channel of the second annular fixing portion 109 and the channel of the connecting portion.

[0049] Preferably, a water cooling space for absorbing the accumulated heat of the first conical mirror 101 is provided inside the lifting bolt and the first conical mirror 101, and a cooling space 110 can be provided inside the parabolic focusing mirror 103 to cool the parabolic focusing mirror 103 and the first conical mirror 101. A knob can be provided on the outer end surface of the adjusting bolt 107 and the duty cycle data can be marked to achieve quantitative adjustment. Further, the laser cladding device also includes a device housing, the device housing is provided with a light inlet channel 100, and the device housing and the second annular fixing portion 109 of the mirror seat cooperate to encapsulate the parabolic focusing mirror 103, so that the light inlet channel 100, the device housing, the parabolic focusing mirror 103, the first conical mirror 101 and the second conical mirror 102 are all coaxially arranged, and the light inlet channel 100 can be used for the laser beam to enter and reach the reflection surface of the first conical mirror 101 and the second conical mirror 102. Further, the laser cladding device also includes a laser source, which is connected to the light inlet channel to incident the laser beam into the light inlet channel.

[0050] The following is an explanation of the situation where the laser cladding device can adjust the duty cycle in a wide range, in which a position other than the upper and lower limit positions is used for specific explanation, and the entire device is simplified. For the convenience of explanation, the light paths at the two limit positions are indicated by dotted lines, as shown in FIG. Figure 5 As shown, Figure 5 This is a schematic diagram of the duty cycle change of the laser cladding device of this embodiment in the selected working plane, and the working plane with a defocus amount of F is taken as an example for explanation.

[0051] Wherein, F represents the defocus amount of the working plane, and D represents the diameter of the ring formed by the focus of the light reflected by the parabolic focusing mirror. L represents the output light path of the second conical mirror, L1 represents the actual output light path of the first conical mirror, L2 represents the output light path at the lower limit position of the first conical mirror, and L3 represents the output light path at the upper limit position of the first conical mirror. C1 represents the light spot at the actual working plane of the first conical mirror, C2 represents the light spot of the output light path at the lower limit position of the first conical mirror, and C3 represents the light spot of the output light path at the upper limit position of the first conical mirror. θ1 represents the angle between the output light path at the actual working position of the first conical mirror and the central axis, and θ2 represents the angle between the output light path at the upper limit position of the first conical mirror and the central axis. θ3 represents the angle between the output light path at the lower limit position of the first conical mirror and the central axis, and θ represents the angle between the output light path of the second conical mirror and the central axis.

[0052] The focus of the light reflected by the parabolic focusing mirror is located on the optical focal plane. A working plane is selected on the side of the optical focal plane close to the parabolic focusing mirror, and the defocus amount of the working plane satisfies:

[0053] .

[0054] When the adjusting bolt 107 is rotated to drive the lifting bolt to move to a certain position, the second cone mirror 102 is located at Figure 5The actual outgoing light path L1 of the first axle is between the outgoing light path L2 of the lower limit position of the first axle and the outgoing light path L3 of the upper limit position of the first axle, which can be regarded as a general situation during laser cladding.

[0055] At this time, the working spot that can be taken on the plane with a defocus amount of F is C1, and its inner radius and outer radius r1 and r2 are respectively:

[0056] ;

[0057] ;

[0058] The maximum light spot on the working plane is the light spot C3 formed by the light path L3 at the upper limit position of the first axon and the light path L at the second axon, and its inner radius and outer radius r3 and r4 are respectively:

[0059] ;

[0060] ;

[0061] The minimum light spot on the working plane is the light spot C2 formed by the light path L2 at the lower limit position of the first axon and the light path L of the second axon, and its inner radius and outer radius r5 and r6 are respectively:

[0062] ;

[0063] ;

[0064] Then the value of the laser duty cycle K in this working plane is:

[0065] ;

[0066] In this embodiment, the duty cycle is the area ratio of the hollow area and the spot area of ​​the annular spot formed by the outgoing light beam on the working plane. Its range of variation is:

[0067] .

[0068] Substitute this into the data commonly used in experiments: , .

[0069] The expected data are: , .

[0070] The expected achievable duty cycle range is 0.185 to 0.668.

[0071] The above is a detailed introduction to a laser cladding device with a wide range of adjustable duty cycles provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A laser cladding device with a wide range of adjustable duty cycle, characterized in that: The invention comprises a parabolic focusing mirror, a first axicon, a second axicon and a powder spraying device, wherein the parabolic focusing mirror and the second axicon are both annular, and the reflection surfaces of the first axicon and the second axicon are opposite to the reflection surface of the parabolic focusing mirror, so that the light beam incident on the first axicon and the second axicon from the central axis of the parabolic focusing mirror is reflected toward the circumference by the reflection surfaces of the two axicon and incident on the reflection surface of the parabolic focusing mirror, and is further reflected and focused by the reflection surface of the parabolic focusing mirror; The position of the second axle is fixed, the first axle can move along the central axis of the parabolic focusing mirror, the powder spraying device is arranged below the second axle, the reflecting surface of the parabolic focusing mirror makes the focus of the light form a ring line around the central axis of the parabolic focusing mirror, and the focus of the light reflected by the parabolic focusing mirror deviates from the central axis of the parabolic focusing mirror; The focus of the light reflected by the parabolic focusing mirror is located on the optical focal plane. There is a preset plane on the side of the optical focal plane close to the parabolic focusing mirror. The light reflected from the parabolic focusing mirror forms a solid light spot on the preset plane, which is formed by the cross-overlapping part of the outgoing light beams. A working plane is selected on the side of the optical focal plane close to the parabolic focusing mirror, and the defocus amount of the working plane satisfies: ； Among them, F represents the defocus amount of the working plane, D represents the diameter of the ring formed by the focus of the light reflected by the parabolic focusing mirror, and θ3 represents the angle between the outgoing light path at the lower limit position of the first conical mirror and the central axis.

2. The laser cladding device with a wide range of adjustable duty cycle according to claim 1 is characterized in that: The duty cycle adjustment range of the light reflected by the parabolic focusing mirror in the selected working plane is: ； Among them, K represents the duty cycle of the light reflected by the parabolic focusing mirror in the selected working plane, θ2 represents the angle between the output light path at the upper limit position of the first conical mirror and the central axis, and θ represents the angle between the output light path of the second conical mirror and the central axis.

3. The laser cladding device with a wide range of adjustable duty cycle according to claim 1 is characterized in that: The inner diameter of the second axle is smaller than or equal to the diameter of the first axle.

4. The laser cladding device with a wide range of adjustable duty cycle according to claim 1, characterized in that: It also includes a mirror seat and a motion adjustment member, the mirror seat includes a first annular fixing portion, the second conical mirror is fixed to the first annular fixing portion, the motion adjustment member is passed through the first annular fixing portion and drives the first conical mirror to move along the central axis of the parabolic focusing mirror, the first conical mirror is fixed to the top end of the motion adjustment member, and the powder spraying device is fixed to the bottom end of the motion adjustment member.

5. The laser cladding device with a wide range of adjustable duty cycle according to claim 4 is characterized in that: The mirror mount also includes a connecting portion for fixing the first annular fixing portion, the motion adjustment member is a lifting bolt, the connecting portion is provided with a channel extending through the first annular fixing portion, an adjusting bolt is provided in the channel, and the first annular fixing portion is provided with a multi-stage bevel gear for transmission connection between the adjusting bolt and the lifting bolt.

6. The laser cladding device with a wide range of adjustable duty cycle according to claim 5, characterized in that: The mirror seat also includes a second annular fixing portion, the parabolic focusing mirror is fixed to the second annular fixing portion, the second annular fixing portion is located at the outer periphery of the first annular fixing portion, and the two are connected by the connecting portion.

7. The laser cladding device with a wide range of adjustable duty cycle according to claim 5, characterized in that: A water cooling space for absorbing the heat accumulated in the first conical mirror is arranged inside the lifting bolt and the first conical mirror, and a cooling space is arranged inside the parabolic focusing mirror.

8. The laser cladding device with a wide range of adjustable duty cycle according to claim 4, characterized in that: It also includes a device housing, which cooperates with the mirror base to encapsulate the parabolic focusing mirror.

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