A composite spiral variable diameter cooling channel structure and metal cutting internal cooling tool

Abstract

The present invention relates to the field of cooling channels for metal cutting internally cooled tools, and more particularly to a composite spiral variable-diameter cooling channel structure and a metal cutting internally cooled tool. The composite spiral variable-diameter cooling channel structure is composed of a variable-diameter acceleration section channel, a composite spiral section channel, a transition section channel, and a trumpet outlet section channel, in sequence from the cooling channel inlet to the cooling channel outlet. Coolant flows from the cooling channel inlet into the variable-diameter acceleration section channel, and L>3D is satisfied; wherein L is the total axial projection length of the cooling channel from the cooling channel inlet to the cooling channel outlet, and D is the cutting diameter of the tool, with a value range of D from 3 mm to 40 mm. The composite spiral variable-diameter cooling channel provided by the present invention achieves a 25% to 35% increase in fluid flow rate while fully retaining the fluid kinetic energy of the coolant through its uniquely structured segmented channels, thereby improving the cooling effect by approximately 30%.

Description

Technical Field

[0001] The present invention relates to the field of cooling channels for metal cutting internally-cooled tools, and in particular to a composite spiral variable-diameter cooling channel structure and a metal cutting internally-cooled tool. Background Art

[0002] The cutting process is mainly divided into turning, drilling, milling and grinding according to the processing type; turning refers to the use of the rotational motion of the workpiece and the linear motion or curved motion of the tool to change the shape and size of the blank; drilling refers to the process of using the tool to machine holes on the workpiece; milling refers to fixing the blank and using a rotating multi-edge tool to cut the workpiece into the required shape and size; boring is a cutting process that uses a tool to enlarge holes or other circular contours; grinding refers to the processing method of using abrasives to remove excess material on the workpiece, which belongs to the finishing of mechanical processing.

[0003] The above-mentioned processing will cool the cutting tool. The traditional cooling method is mainly the pouring method (external cooling). This method uses a large amount of cutting fluid to pour into the technician area to ensure actual processing needs. However, this method obviously leads to an increase in processing costs, and is not effective in special processing methods such as deep hole processing. The use of a large amount of cutting fluid can easily cause environmental pollution and is harmful to the health of equipment operators.

[0004] At present, the main method is to use the punching process to process the cooling channel in the cutting tool itself. The conventional cooling channel structure of the existing metal cutting internal cooling tool is as follows: Figures 1 to 5 As shown, this metal cutting internal cooling tool Z has a double cooling channel structure, and the cross-sectional shape of its cooling channel (1) is all circular, and the structure is relatively simple. Except for the area near the channel outlet, the entire channel has almost no significant diameter change structure. This is a cooling channel structure commonly used at present. This cooling channel structure has low cooling efficiency and poor cooling effect. At the same time, the cooling channel is prone to scale accumulation, resulting in further reduction of the cooling effect, so it needs further improvement. Summary of the Invention

[0005] In order to solve the problem of low cooling efficiency of the dual cooling channel structure of the metal cutting internal cooling tool in the above-mentioned prior art, the present invention provides a composite spiral variable diameter cooling channel structure. From the cooling channel inlet to the cooling channel outlet, the structure is composed of a variable diameter acceleration section flow channel, a composite spiral section flow channel, a transition section flow channel and a trumpet outlet section flow channel. The coolant flows from the cooling channel inlet into the variable diameter acceleration section flow channel, and satisfies L>3D;

[0006] Wherein, L is the total axial projection length of the cooling channel from the cooling channel inlet to the cooling channel outlet, D is the cutting diameter of the tool, and the value range of D is 3mm to 40mm.

[0007] In one embodiment, the variable-diameter acceleration section flow channel is composed of an inlet transition straight channel, m reduced-diameter flow channels, and n short straight channels, and satisfies mL5+nΔ1+L7≤L1, and L1≥2D, L7≥D / 5;

[0008] Among them, L1 is the axial projection length of the variable diameter acceleration section flow channel, L7 is the axial projection length of the inlet transition straight channel, Δ1 is the axial projection length of the short straight channel, and L5 is the axial projection length of the reduced diameter flow channel.

[0009] In one embodiment, the composite spiral segment flow channel consists of a central circular flow channel and k auxiliary flow channels uniformly distributed along the periphery of the central circular flow channel, where k is an integer greater than 1 and satisfies L2>D, R1≤D / 4, 0.5D3≥R2>R1≥0.1D3, and D3≤D / 2;

[0010] Wherein, L2 is the axial projection length of the composite spiral section flow channel, R1 is the radius of the auxiliary flow channel, R2 is the radius of the central circular flow channel, and D3 is the circumscribed circle diameter of the cross section of the composite spiral section flow channel.

[0011] In one embodiment, the structure of the central circular flow channel is formed by a circle with a radius R2 swept along the central axis A, and the structure of the auxiliary flow channel is formed by an arc with a radius R1 swept along the spiral curve A1, and the following conditions are satisfied: β ≥ 0°, D4 < D, D5 ≤ D / 2, L6 ≥ 2D;

[0012] The central axis A is a spiral curve with a spiral diameter of D4 and a spiral angle of β, and the spiral curve A1 is a spiral curve with the spiral curve A as the spiral center line, a spiral diameter of D5, and a pitch of L6.

[0013] In one embodiment, the intersection transition positions of the k auxiliary flow channels and the transition section flow channels form k intersection structures, and the k intersection structures are all curved surface structures with a curvature radius of R3, wherein R3=R1≤D / 4 is satisfied.

[0014] In one embodiment, the transition section flow channel is a reduced diameter structure, the cross-sectional diameter size of the transition section flow channel at the location where it connects with the compound spiral section flow channel is 2R2, the cross-sectional diameter size of the transition section flow channel at the location where it connects with the trumpet outlet section flow channel is D2, and the following conditions are satisfied: 2R2 ≥ d3 ≥ D2, L3 ≥ D / 10;

[0015] Wherein, L3 is the axial projection length of the transition section flow channel, and d3 is the cross-sectional circle diameter at the middle position of the transition section flow channel in a direction perpendicular to the central axis J.

[0016] In one embodiment, the bell outlet section flow channel is a variable diameter structure and satisfies D2≤d3, d1≤0.9D2, L4≥0.25D;

[0017] Wherein, L4 is the axial projection length of the flow channel, D2 is the diameter of the circular section at both ends of the flow channel, and d1 is the diameter of the circular section in the middle of the flow channel.

[0018] In one embodiment, the surface roughness of the inner walls of the variable-diameter acceleration section flow channel, the compound spiral section flow channel, the transition section flow channel, and the trumpet outlet section flow channel does not exceed Ra6.3.

[0019] The present invention also provides a metal cutting internal cooling tool, which adopts any of the above-mentioned composite spiral variable-diameter cooling channel structures.

[0020] Based on the above, compared with the existing technology, in summary, the composite spiral variable diameter cooling flow channel provided by the present invention achieves a 25% to 35% increase in the flow rate of the fluid while fully retaining the fluid kinetic energy of the coolant through the unique structure of the various segmented flow channels, namely the variable diameter acceleration section flow channel, the composite spiral section flow channel, the transition section flow channel and the trumpet outlet section flow channel, thereby improving the cooling effect by about 30%. At the same time, the fluid is used to form a relatively regular spiral flow in the flow channel, reducing the contact laminar thickness between the fluid and the flow channel wall, thereby reducing scale accumulation on the flow channel surface, greatly improving the flow channel wall environment, and avoiding the problem of the flow channel being blocked or even blocked due to scale accumulation.

[0021] Other features and beneficial effects of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The objectives and other beneficial effects of the present invention can be achieved and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work. The positional relationships described in the drawings in the following description are based on the directions of the components drawn in the diagrams, unless otherwise specified.

[0023] Figure 1 It is a three-dimensional schematic diagram of the axis of a conventional cooling channel of an existing metal cutting internal cooling tool;

[0024] Figure 2 It is a three-dimensional schematic diagram of two conventional cooling channels;

[0025] Figure 3 A top view of two conventional cooling channels of an existing metal cutting tool with internal cooling;

[0026] Figure 3.1 for Figure 3 Cross-sectional view along GG;

[0027] Figure 3.2 for Figure 3 Cross-sectional view along the middle FF;

[0028] Figure 3.3 for Figure 3 Cross-sectional view along EE;

[0029] Figure 3.4 for Figure 3 Cross-sectional view along CC;

[0030] Figure 4 for Figure 3 Front view of two conventional cooling channels;

[0031] Figure 5 for Figure 4 Left view of two conventional cooling channels in;

[0032] Figure 6 A schematic 3D diagram of the axis of the composite spiral variable-diameter cooling channel of the metal cutting internal cooling tool provided by the present invention;

[0033] Figure 7 It is a three-dimensional schematic diagram of two composite spiral variable-diameter cooling channels provided by the present invention;

[0034] Figure 8 A top view of two composite spiral variable-diameter cooling channels of the metal cutting internal cooling tool provided by the present invention;

[0035] Figure 8.1 for Figure 8 Cross-sectional view along NN;

[0036] Figure 8.2 for Figure 8 Cross-sectional view along the middle MM;

[0037] Figure 8.3 for Figure 8 Cross-sectional view along KK;

[0038] Figure 8.4 for Figure 8 Cross-sectional view along HH;

[0039] Figure 9 for Figure 8 The front view of the two compound spiral variable diameter cooling channels;

[0040] Figure 10 for Figure 9 Left view of the two compound spiral reducing cooling channels;

[0041] Figure 11 A front view of a single composite spiral variable-diameter cooling channel of a metal cutting internally cooled tool according to an embodiment of the present invention;

[0042] Figure 11.1 for Figure 11 A magnified schematic diagram of S1 in the middle;

[0043] Figure 11.1a Schematic diagram of the relationship (Pythagorean theorem) between R4 and d1, D2, and L4;

[0044] Figure 11.2 for Figure 11 A magnified schematic diagram of S2 in the middle;

[0045] Figure 11.3 for Figure 11 A magnified schematic diagram of S3 in the middle;

[0046] Figure 11.3a Schematic diagram of the relationship (Pythagorean theorem) between R5 and d2, D3, and L5;

[0047] Figure 12 for Figure 11 A top view of a single composite spiral variable-diameter cooling channel;

[0048] Figure 12.1 for Figure 12 A magnified schematic diagram of S4 in the middle;

[0049] Figure 12.2 for Figure 12 Cross-sectional view along the PP;

[0050] Figure 12.3 for Figure 12 Cross-sectional view along SS;

[0051] Figure 13 for Figure 11 Left view of a single composite spiral variable-diameter cooling channel;

[0052] Figure 14 for Figure 11 A front view of a single composite spiral variable-diameter cooling channel after rotating 180° around axis J;

[0053] Figure 15 for Figure 14 A top view of a single composite spiral variable-diameter cooling channel;

[0054] Figure 15.1 for Figure 15 Cross-sectional view along TT;

[0055] Figure 15.2 for Figure 15 Cross-sectional view along YY;

[0056] Figure 16 for Figure 14 Left view of a single composite spiral variable-diameter cooling channel;

[0057] Figure 17 3D schematic diagram of the spiral curves of the composite spiral section flow channels of the two composite spiral variable-diameter cooling flow channels in an embodiment of the present invention;

[0058] Figure 18 for Figure 17 A top view of the spiral curve of the compound spiral section flow channel;

[0059] Figure 19 for Figure 17 A front view of the spiral curve of the compound spiral section flow channel;

[0060] Figure 20 Schematic diagram of the spiral curve size structure of the composite spiral section flow channel in an embodiment of the present invention;

[0061] Figure 21.1 This is a simulation cloud diagram of the effect of the variable diameter acceleration section flow channel on fluid acceleration in an embodiment of the present invention;

[0062] Figure 21.2 This is a simulation trace diagram of the effect of the variable diameter acceleration section flow channel on fluid acceleration in an embodiment of the present invention;

[0063] Figure 22 1 is a diagram showing simulation results of the fluid acceleration effect of the transition section flow channel and the trumpet outlet section flow channel in an embodiment of the present invention;

[0064] Figure 23 This is a simulation result diagram of the effect of transition channels and outlet straight channels on fluid acceleration in conventional cooling channels.

[0065] Reference numerals:

[0066] 1 Conventional cooling channel 2 Composite spiral variable diameter cooling 11 Inlet straight channel

[0067] runner

[0068] 12 curved flow channel 13 transition flow channel 14 outlet straight flow channel

[0069] 21 variable diameter acceleration section flow channel 22 compound spiral section flow channel 23 transition section flow channel

[0070] 24 trumpet outlet section flow channel 211 inlet transition straight channel 212 reduced diameter flow channel

[0071] 213 short straight channel 220 central circular channel 221 auxiliary channel

[0072] 222 Interconnection structure 100 Cooling channel inlet 200 Cooling channel outlet DETAILED DESCRIPTION

[0073] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 part of the embodiments of the present invention, not all of the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0074] In the description of the present invention, it should be noted that all terms used in the present invention (including technical terms and scientific terms) have the same meanings as those generally understood by ordinary technicians in the field to which the present invention belongs, and should not be understood as limiting the present invention; it should be further understood that the terms used in the present invention should be understood to have meanings consistent with the meanings of these terms in the context of this specification and in the relevant fields, and should not be understood in an idealized or overly formal sense, unless explicitly defined as such in the present invention.

[0075] In order to more clearly explain the technical problems and causes of the existing conventional cooling channels, before describing the specific embodiments of the present invention, Figures 1 to 5 The existing conventional cooling channels are further described as follows:

[0076] Figures 1 to 5 The example of an existing metal cutting internal cooling tool Z using two conventional cooling channels 1 is shown. The conventional cooling channel 1 mainly consists of an inlet straight channel 11, a curved channel 12, a transition channel 13 and an outlet straight channel 14. The cross-sectional shape of the conventional cooling channel 1 in the direction perpendicular to the axis J is all circular, as shown in FIG. Figure 3 Section CC in Figure 3.4 , Section EE, see Figure 3.3 , Section FF, see Figure 3.2 and cross-section GG, see Figure 3.1 .

[0077] Among them, reference Figure 4The axial projection length of the inlet straight channel 11 is L1, and the cross-sectional circle diameter size is D1. The axial projection length of the curved flow channel 12 is L2, and the cross-sectional circle diameter size is D1. The axial projection length of the transition flow channel 13 is L3, and the cross-sectional circle diameter size in the middle position along the direction perpendicular to the central axis J is d. The axial projection length of the outlet straight channel 14 is L4, and the cross-sectional circle diameter size is D2. The dimensions D1 and d satisfy: D / 2≥D1≥d≥D2, where D is the cutting diameter of the tool, and the value range of D is 3mm to 40mm.

[0078] The problem with the conventional cooling channel 1 is that the overall structure is single, and except for the transition channel 13 near the channel outlet, the entire channel has almost no significant variable diameter structure, which means that the cross-sectional shape and size of the channel are basically single and fixed, resulting in basically no significant change in the flow rate of the coolant when flowing through the conventional cooling channel 1. In addition, the surface roughness of the inner wall of the conventional cooling channel 1 is usually greater than Ra6.3, which will cause the coolant to generate greater friction resistance with the contact wall when flowing through the channel, and the contact laminar thickness between the fluid and the channel wall is greater, resulting in more fluid kinetic energy loss, ultimately resulting in low cooling efficiency and poor cooling effect of this conventional cooling channel 1. At the same time, when the coolant is used for cooling for a long time, the cooling channel is more likely to accumulate scale, causing the cooling effect to be further reduced.

[0079] Reference Figures 6 to 16 In order to overcome the problems of the conventional cooling channel 1, the present invention provides an embodiment of a composite spiral variable diameter cooling channel, such as Figure 7 As shown, its specific structure is composed of a variable diameter acceleration section flow channel 21, a compound spiral section flow channel 22, a transition section flow channel 23 and a trumpet outlet section flow channel 24 in sequence from the cooling flow channel inlet 100 to the cooling flow channel outlet 200. The coolant flows from the cooling flow channel inlet 100 into the variable diameter acceleration section flow channel 21, is accelerated by the variable diameter acceleration section flow channel 21 to flow into the compound spiral section flow channel 22, forms a relatively regular spiral flow in the compound spiral section flow channel 22, then enters the transition section flow channel 23, and finally flows out from the trumpet outlet section flow channel 24.

[0080] Figure 6 A is the central axis of the composite spiral section flow channel. Note: The central axis A is a spiral curve; A1 is the sweep trajectory line forming the auxiliary flow channel. Note: A1 is a spiral curve; J is the axis of the metal cutting internal coolant tool; Z is the metal cutting internal coolant tool; D is the cutting diameter of the tool.

[0081] Reference Figure 8The total axial projection length of the cooling channel from the cooling channel inlet 100 to the cooling channel outlet 200 is L, the axial projection length of the variable diameter acceleration section channel 21 is L1, the axial projection length of the compound spiral section channel 22 is L2, the axial projection length of the transition section channel 23 is L3, and the axial projection length of the trumpet outlet section channel 24 is L4, where L = L1 + L2 + L3 + L4, and L> 3D, where D is the cutting diameter of the tool, see Figure 6 , the value range of D is 3mm to 40mm.

[0082] In one embodiment, referring to Figure 11 Or 12, the variable diameter acceleration section flow channel 21 is composed of an inlet transition straight channel 211, m reduced diameter flow channels 212 and n short straight channels 213, and satisfies mL5+nΔ1+L7≤L1, and L1≥2D, L7≥D / 5,

[0083] Among them, L1 is the axial projection length of the variable-diameter acceleration section flow channel 21, L7 is the axial projection length of the inlet transition straight channel 211, Δ1 is the axial projection length of the short straight channel 213, and L5 is the axial projection length of the reduced-diameter flow channel 212.

[0084] Figure 11 In the embodiment shown in , m=3, n=3, that is, the structure of the variable diameter acceleration section flow channel 21 of this embodiment is composed of an inlet transition straight channel 211, three reduced diameter flow channels 212 and three short straight channels 213, wherein the inlet transition straight channel 211 is a straight channel with a length of L7, a circular cross-section shape and a circular diameter of D3, the short straight channel 213 is a straight channel with a length of Δ1, a circular cross-section shape and a circular diameter of D3, the reduced diameter flow channel 212 has a circular cross-section shape and a flow channel length dimension of L5, as shown in FIG. Figure 8.3 The diameter of the circular cross section at both ends of the reduced diameter flow channel 212 is D3, and the diameter of the circular cross section in the middle of the flow channel is d2. Figure 11.3 or Figure 8.4 The outer generatrix of the flow channel is an arc, and its arc radius is R5. Figure 11.3

[0085] Specifically, in this embodiment, the dimensions Δ1, D3, d2, L5, and R5 are respectively: Δ1=0.8D3, d2=0.9D3, L5=2D3, D3=D / 4, where D is the cutting diameter of the tool, and in this embodiment, D is 16 mm.

[0086] Reference Figure 11.3a , R5 and d2, D3, L5 satisfy the relationship (Pythagorean theorem): Right now

[0087] This regularly distributed alternating diameter reduction structure can effectively increase the coolant flow rate through the flow channel section while minimizing kinetic energy loss. Generally, under the conditions of ensuring mL5+nΔ1+L7≤L1 and L1≥2D, L7≥D / 5, the larger the values ​​of m and n, the better the speed-increasing effect of the variable diameter acceleration section flow channel 21 on the coolant. Here, when m=3 and n=3, the variable diameter acceleration section flow channel 21 can increase the coolant flow rate by about 30%. Its speed-increasing effect has been verified by fluid simulation, such as Figure 21.1 and Figure 21.2 shown.

[0088] It should be noted that Figure 21.1 For simulation cloud map, Figure 21.2 This is a simulation trace graph. Both graphs represent the effect of fluid acceleration, but the presentation format differs slightly. The cloud graph presents the results by coloring the regions, while the trace graph presents the results by combining color with trajectory lines.

[0089] In one embodiment, the composite spiral flow channel 22 is composed of a central circular flow channel 220 and k auxiliary flow channels 221 evenly distributed along the periphery of the central circular flow channel 220, where k is an integer greater than 1 and satisfies L2>D, R1≤D / 4, 0.5D3≥R2>R1≥0.1D3, and D3≤D / 2;

[0090] Wherein, L2 is the axial projection length of the composite spiral section flow channel 22, R1 is the radius of the auxiliary flow channel 221, see Figure 8.3 、 Figure 12.2 or Figure 15.1 , R2 is the radius of the central circular flow channel 220, see Figure 8.3 、 Figure 12.2 or Figure 15.1 , D3 is the diameter of the circumscribed circle of the cross section of the composite spiral section flow channel 22.

[0091] Specifically, refer to Figure 11 Or 12, the composite spiral section flow channel 22 is a composite spiral structure, the axial projection length of the flow channel is L2, and the cross-sectional shape of the flow channel is a flower-shaped cross-section composed of multiple arc segments, see Figure 8.3 、 Figure 12.2 or Figure 15.1The center area of ​​the cross section is a circle with a radius of R2, and the center area of ​​the cross section is connected to k evenly distributed arcs with a radius of R1, forming a flower-shaped cross section composed of multiple arcs. The circumscribed circle diameter of the cross section is D3, where k, L2, R1, R2, and D3 respectively satisfy: k≥2, L2>D, R1≤D / 4, 0.5D3≥R2>R1≥0.1D3, D3≤D / 2. In this embodiment, the values ​​of k, L2, R1, R2, and D3 are: k=4, L2=5D, R1=3D / 64, R2=2R1=3D / 32, and D3=D / 4.

[0092] In one embodiment, referring to Figures 18 to 20 The structure of the central circular flow channel 220 is formed by a circle with a radius of R2 sweeping along the central axis A, and the structure of the auxiliary flow channel 221 is formed by an arc with a radius of R1 sweeping along the spiral curve A1, and the following conditions are satisfied: β ≥ 0°, D4 < D, D5 ≤ D / 2, L6 ≥ 2D;

[0093] The central axis A is a spiral curve with a spiral diameter of D4 and a spiral angle of β, and the spiral curve A1 is a spiral curve with the spiral curve A as the spiral center line, a spiral diameter of D5, and a pitch of L6.

[0094] In this embodiment, the values ​​of β, D4, D5, and L6 are: β = 8°, D4 = 0.525D, D5 = 3D / 16, and L6 = 35D / 16, respectively. Therefore, when the coolant passes through the variable-diameter acceleration section flow channel 21 and accelerates to flow into the compound spiral section flow channel 22, the special composite spiral structure of the composite spiral section flow channel 22 will cause the coolant to form a relatively regular spiral flow in the flow channel. This spiral flow will reduce the thickness of the contact laminar flow formed between the coolant and the flow channel wall when it flows, thereby reducing the accumulation of scale on the flow channel surface, greatly improving the flow channel wall environment, and avoiding the problem of the flow channel being blocked or even blocked due to scale accumulation. In this embodiment, the value of D is also 16 mm, but in fact, for tools with smaller cutting diameters D, the effect of this structure is more prominent.

[0095] In one embodiment, the intersection transition positions of the k auxiliary flow channels 221 and the transition section flow channels 23 will form k intersection structures 222, and the k intersection structures 222 are all curved surface structures with a curvature radius of R3, where R3=R1≤D / 4 is satisfied.

[0096] Specifically, refer to Figure 10 、 Figure 11.2 、 Figure 12.1 、 Figure 12.2 、 Figure 13 、 Figure 15.1 or Figure 16In this embodiment, k = 4 and R3 = 3D / 64. This means that at this point, four intersection structures 222 are formed at the intersections between the four auxiliary channels 221 of the compound spiral channel 22 and the transition channel 23. These four intersection structures 222 all have a curved surface with a radius of curvature of 3D / 64. This intersection structure allows the coolant to gradually decrease in cross-sectional area as it flows from the compound spiral channel 22 into the transition channel 23. This minimizes the loss of fluid kinetic energy caused by the sudden change in channel cross-sectional shape and further increases the coolant's flow rate before entering the transition channel 23.

[0097] In one embodiment, the transition section flow channel 23 is a reduced diameter structure, and the cross-sectional diameter size of the position where it connects with the compound spiral section flow channel 22 is 2R2, and the cross-sectional diameter size of the position where it connects with the trumpet outlet section flow channel 24 is D2, and the following conditions are satisfied: 2R2 ≥ d3 ≥ D2, L3 ≥ D / 10;

[0098] Wherein, L3 is the axial projection length of the transition section flow channel 23, d3 is the cross-sectional diameter of the middle position of the transition section flow channel 23 along the direction perpendicular to the central axis J, see Figure 8.2 .

[0099] Specifically, refer to Figure 8 and Figure 8.2 ,or Figure 9 and Figure 11 In this embodiment, the values ​​of R2, D2, d3, and L3 are: R2 = 3D / 32, D2 = 5D / 32, d3 = 11D / 64, and L3 = 3D / 4. This reduced diameter structure maximizes the kinetic energy of the fluid while further increasing the coolant flow rate as it flows through this section of the flow channel.

[0100] In one embodiment, the bell outlet section flow channel 24 is a variable diameter structure and satisfies D2≤d3, d1≤0.9D2, L4≥0.25D. Figure 11.1 ;

[0101] Wherein, L4 is the axial projection length of the flow channel, D2 is the diameter of the circular section at both ends of the flow channel, and d1 is the diameter of the circular section in the middle of the flow channel.

[0102] In one embodiment, the outer peripheral generatrix of the bell outlet section flow channel 24 is an arc shape, and the arc radius is R4. Figure 11.1 ;

[0103] Reference Figure 11.1a , R4 and d1, D2, L4 satisfy the relationship (Pythagorean theorem): Right now

[0104] The coolant is accelerated through the transition section flow channel 23 and then flows into the bell outlet section flow channel 24. When the coolant flows into the bell outlet section flow channel 24, since the cross-sectional area of ​​the flow channel first decreases and then increases, the flow channel will produce a squeezing effect on the flowing coolant, in which the pressure first increases and then decreases, thereby further increasing the flow rate of the coolant. The speed-up effect has been verified by fluid simulation, such as Figure 22 As shown, the flow rate of the coolant when entering the transition section flow channel 23 is 10m / s, while the flow rate out of the trumpet outlet section flow channel 24 can reach 20m / s. It can be concluded that the speed-up effect is close to 100%. Generally, the flow rate of the coolant can be increased by at least 50% to 100% after flowing through the transition section flow channel 23 and the trumpet outlet section flow channel 24.

[0105] In addition, the present invention also provides Figures 1 to 5 The simulation results of the speed-increasing effect of the conventional cooling channel embodiment at the same position of the channel structure are shown in FIG. Figure 23 , and the speed-increasing effect is approximately 35% (i.e., the coolant has a flow rate of 10 m / s when entering the transition channel 13, and a flow rate of 13.5 m / s when exiting the outlet straight channel 14). Therefore, in terms of the effect, in the cooling channel structure provided by the present invention, the speed-increasing performance of this section of the channel is improved by approximately 48% compared to the channel section at the same position in the conventional channel.

[0106] The present invention also provides a metal cutting internal cooling tool, which adopts any of the above-mentioned composite spiral variable diameter cooling channel structures, referring to Figure 6 Specifically, two composite spiral variable-diameter cooling channels 2 are used.

[0107] To sum up, the composite spiral variable diameter cooling channel provided by the present invention achieves a 25% to 35% increase in the flow rate of the fluid while fully retaining the fluid kinetic energy of the coolant through the unique structure of the various segmented channels, namely the variable diameter acceleration section flow channel, the composite spiral section flow channel, the transition section flow channel and the trumpet outlet section flow channel, thereby improving the cooling effect by about 30%. At the same time, the fluid is used to form a relatively regular spiral flow in the flow channel, reducing the contact laminar thickness between the fluid and the flow channel wall, thereby reducing scale accumulation on the flow channel surface, greatly improving the flow channel wall environment, and avoiding the problem of the flow channel being blocked or even blocked due to scale accumulation.

[0108] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention may be improved in only one or several aspects, without having to simultaneously solve all the technical problems listed in the prior art or background art. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as limiting the claim.

[0109] Although the terms such as conventional cooling channel, compound spiral variable diameter cooling channel, inlet straight channel, curved channel, transition channel, outlet straight channel, variable diameter acceleration section channel, compound spiral section channel, transition section channel, trumpet outlet section channel, inlet transition straight channel, reduced diameter channel, short straight channel, central circular channel, auxiliary channel, junction structure, cooling channel inlet, cooling channel outlet, etc. are used more frequently in this article, the possibility of using other terms is not excluded. The use of these terms is only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention; the terms "first", "second", etc. (if any) in the description and claims of the embodiments of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite spiral variable diameter cooling channel structure, characterized by: The structure from the cooling channel inlet (100) to the cooling channel outlet (200) is composed of a variable diameter acceleration section channel (21), a compound spiral section channel (22), a transition section channel (23) and a trumpet outlet section channel (24) in sequence. The coolant flows from the cooling channel inlet (100) into the variable diameter acceleration section channel (21), and L>3D is satisfied. Wherein, L is the total axial projection length of the cooling channel from the cooling channel inlet (100) to the cooling channel outlet (200), and D is the cutting diameter of the tool, and the value range of D is 3 mm to 40 mm; The composite spiral section flow channel (22) is composed of a central circular flow channel (220) and k auxiliary flow channels (221) uniformly distributed along the periphery of the central circular flow channel (220), where k is an integer greater than 1; The structure of the central circular flow channel (220) is formed by sweeping a circle with a radius of R2 along the central axis A, and the structure of the auxiliary flow channel (221) is formed by sweeping an arc with a radius of R1 along the spiral curve A1.

2. The composite spiral variable-diameter cooling channel structure according to claim 1, characterized in that: The variable-diameter acceleration section flow channel (21) is composed of an inlet transition straight flow channel (211), m reduced-diameter flow channels (212), and n short straight flow channels (213), and satisfies mL5+nΔ1+L7≤L1, and L1≥2D, L7≥D / 5; Wherein, L1 is the axial projection length of the variable diameter acceleration section flow channel (21), L7 is the axial projection length of the inlet transition straight flow channel (211), Δ1 is the axial projection length of the short straight flow channel (213), and L5 is the axial projection length of the reduced diameter flow channel (212).

3. The composite spiral variable-diameter cooling channel structure according to claim 2, characterized in that: The size relationship of the composite spiral section flow channel (22), the central circular flow channel (220), and the auxiliary flow channel (221) satisfies L2>D, R1≤D / 4, 0.5D3≥R2>R1≥0.1D3, D3≤D / 2; Wherein, L2 is the axial projection length of the composite spiral section flow channel (22), R1 is the radius of the auxiliary flow channel (221), R2 is the radius of the central circular flow channel (220), and D3 is the circumscribed circle diameter of the cross section of the composite spiral section flow channel (22).

4. The composite spiral variable-diameter cooling channel structure according to claim 3, characterized in that: The size relationship between the central circular flow channel (220) and the auxiliary flow channel (221) satisfies: β≥0°, D4<D, D5≤D / 2, L6≥2D; The central axis A is a spiral curve with a spiral diameter of D4 and a spiral angle of β, and the spiral curve A1 is a spiral curve with the spiral curve A as the spiral center line, a spiral diameter of D5, and a pitch of L6.

5. The composite spiral variable-diameter cooling channel structure according to claim 3, characterized in that: The intersection transition positions of the k auxiliary flow channels (221) and the transition section flow channel (23) form k intersection structures (222), and the k intersection structures (222) are all curved surface structures with a curvature radius of R3, wherein R3=R1≤D / 4 is satisfied.

6. The composite spiral variable-diameter cooling channel structure according to claim 3, characterized in that: The transition section flow channel (23) is a reduced diameter structure, and the cross-sectional circular diameter size at the position where it connects with the composite spiral section flow channel (22) is 2R2, and the cross-sectional circular diameter size at the position where it connects with the trumpet outlet section flow channel (24) is D2, and the following conditions are satisfied: 2R2 ≥ d3 ≥ D2, L3 ≥ D / 10; Wherein, L3 is the axial projection length of the transition section flow channel (23), and d3 is the diameter of the cross-section circle at the middle position of the transition section flow channel (23) in a direction perpendicular to the central axis J.

7. The composite spiral variable-diameter cooling channel structure according to claim 6, characterized in that: The bell outlet section flow channel (24) is a variable diameter structure and satisfies D2≤d3, d1≤0.9D2, and L4≥0.25D; Among them, L4 is the axial projection length of the bell outlet section flow channel, D2 is the circular cross-sectional diameter at both ends of the bell outlet section flow channel, and d1 is the circular cross-sectional diameter in the middle of the bell outlet section flow channel.

8. The composite spiral variable-diameter cooling channel structure according to claim 7, characterized in that: The outer peripheral generatrix of the reduced diameter flow channel (212) is in the shape of an arc, and the arc radius is R5. ; Wherein, d2 is the diameter of the middle circular cross section of the reduced diameter flow channel (212); The outer peripheral generatrix of the bell outlet section flow channel (24) is in the shape of an arc, and the radius of the arc is R4. .

9. The composite spiral variable-diameter cooling channel structure according to claim 1, characterized in that: The surface roughness of the inner walls of the variable-diameter acceleration section flow channel (21), the composite spiral section flow channel (22), the transition section flow channel (23), and the trumpet outlet section flow channel (24) does not exceed Ra6.

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10. A metal cutting tool with internal cooling, characterized in that: The composite spiral variable diameter cooling channel structure as claimed in any one of claims 1 to 9 is adopted.

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