Combined type drilling reamer for fine hole machining

Abstract

The utility model discloses a combined type drilling reamer for fine hole machining. A tool bit of the combined type drilling reamer comprises two blade sections and two chip removal main grooves formed between the two blade sections, each blade section is provided with a first blade strip and a second blade strip in the clockwise direction, and a chip removal auxiliary groove is formed between the first blade strip and the second blade strip in each set. The two blade flaps, and the first blade strip and the second blade strip which are arranged on the two blade flaps are symmetrically arranged relative to the center of the cross section of the cutter body; the height of the radial section of the lower end of the first edge strip is smaller than that of the radial section of the lower end of the second edge strip, the radial distance of the first edge strip relative to the central axis is smaller than that of the second edge strip relative to the central axis, rough hole machining is conducted on the first edge strip, and then hole reaming and finish machining are conducted on the second edge strip. The utility model has the effects of reducing the tool changing time, increasing the cutting efficiency and the equipment utilization rate, saving the cost and meeting the requirements of large-scale production.

Description

Technical Field

[0001] The utility model relates to the field of machining, and particularly relates to a composite drill reamer for precision hole machining. Background Art

[0002] In industries such as automobiles, aerospace, medical devices, ships, and machine tool manufacturing, many parts involved need to machine precision holes, such as hydraulic power valve holes, engine injector holes, positioning holes, etc.; such holes have many associated dimensions, complex dimensional structures, and high precision requirements. Their common hole depths are within 5 times the diameter, the precision requirement is H6 / H7, and the surface roughness requirement is below 1.6. Therefore, they belong to the difficulties in machining. The traditional process method: first, use a drill bit to rough machine the hole position and leave a margin for the reamer, and then use the reamer to finish machine the rough machined hole. Its defects are as follows: First, one drill and one ream, it is necessary to replace and reposition the tool, the machining is cumbersome, more tool library positions are required, the machining cost is high, the machining efficiency is low, and it is difficult to meet the needs of large-scale production; second, the machining benchmark has deviation due to multiple replacements of machining tools, which affects the machining quality of the product; third, the chips cannot be discharged in time and quickly after cutting, resulting in difficulty in the smooth cutting process, large cutting deformation, and poor surface quality of the drilled hole. Content of the Utility Model

[0003] In order to solve one or more of the above problems, the utility model provides a composite drill reamer for precision hole machining.

[0004] According to one aspect of the utility model, the composite drill reamer for precision hole machining includes a cylindrical tool body, one end of the tool body forms a tool head and the other end forms a tool shank; it is characterized in that:

[0005] The tool head includes two cutting lips and two main chip flutes formed between the two cutting lips. Each cutting lip is respectively provided with a first land and a second land in the clockwise direction. A secondary chip flute is formed between each group of the first land and the second land. The two cutting lips and the first lands and second lands arranged on the two cutting lips are all symmetrically arranged about the cross-sectional center of the tool body;

[0006] The height of the radial section at the lower end of the first land is lower than the height of the radial section at the lower end of the second land, and the radial distance of the first land relative to the central axis is shorter than the radial distance of the second land relative to the central axis. The first land first rough machines the hole, and the second land then reams and finishes machines the hole;

[0007] The cutting lips, the first lands, the second lands, the main chip flutes, and the secondary chip flutes all extend spirally along the axis of the tool body.

[0008] In some embodiments, the value H by which the height of the radial section at the lower end of the first land is lower than the height of the radial section at the lower end of the second land is 0.05 mm - 0.08 mm.

[0009] In some embodiments, a rear angled surface that slopes inward is provided behind the second land.

[0010] In some embodiments, the angle between the rear angled surface and the radial surface is 5° - 7°.

[0011] In some embodiments, the width of the first land is 5% - 7% of the tool diameter;

[0012] The width of the second land is 1.2% - 2.8% of the tool diameter.

[0013] In some embodiments, the internal cooling holes of the tool body extend helically along the axial direction of the tool body and penetrate through the tool shank and the tool tip at both ends, and their helical arrangement is consistent with the direction of the cutting lips.

[0014] In some embodiments, an inverted conical transition section is further provided between the tool shank and the tool tip, and its taper is 30°;

[0015] Or the tool shank is cylindrical or inverted conical; the tool tip is inverted conical.

[0016] In some embodiments, an outer coating with wear resistance, surface heat insulation, and surface lubrication is formed on the outer surface of the tool tip by means of a coating technology.

[0017] In some embodiments, the outer coating is a PVD physical vapor deposition coating.

[0018] In some embodiments, the tool body is made of cemented carbide of ISO grade K20 - 30.

[0019] The composite drill reamer for precision hole machining adopts a first land and a second land integrally arranged on the cutting edge lobe. During the rotation of the tool, it always ensures that the first land participates in cutting first, playing a rough machining role, and the second land can play the role of reaming, completing precision hole machining at one time. In addition, a main chip flute and a secondary chip flute are provided for rapid and effective chip evacuation. Its beneficial effects are as follows: First, for the composite drill reamer adopting this scheme, there is no need to change the tool, no need to first drill a bottom hole with a drill bit and directly process, so the rough machining process can be omitted, which can greatly improve the machining efficiency. At the same time, there is no need to change and reposition the tool twice, reducing the tool change time, simplifying the machining process, reducing the tool library positions, greatly increasing the cutting efficiency, increasing the equipment utilization rate. Especially when machining steel parts and cast iron parts, it saves costs and improves efficiency, meeting the needs of large-scale production; Second, there is no need to change the tool and no need for multiple positioning, with a consistent machining datum and high product quality; Third, by setting the main chip flute and the secondary chip flute, chips are evacuated promptly and quickly after cutting, the cutting process is stable, the cutting deformation is small, ensuring the surface quality of the drilled hole. At the same time, it is convenient to perform multiple grinding operations, improving the maintenance convenience and service life of the cutting tool; Fourth, the first land and the second land can also play a role in reducing friction, ensuring the cutting accuracy and cutting speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. is a front view schematic diagram of a composite drill reamer for precision hole machining according to an embodiment of the present invention;

[0021] Figure 2 is Figure 1 a partially enlarged schematic diagram of the composite drill reamer for precision hole machining shown;

[0022] Figure 3 is Figure 1 a bottom view schematic diagram of the composite drill reamer for precision hole machining shown;

[0023] Figure 4 is Figure 3 a magnified schematic diagram at position A of the composite drill reamer for precision hole machining shown;

[0024] tool body 01;

[0025] tool tip 1, cutting edge lobe 10, first land 101, second land 102, secondary chip flute 103, flank face 104, main chip flute 11;

[0026] tool shank 2;

[0027] internal coolant hole 3;

[0028] transition section 4. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present utility model will be further described in detail below with reference to the accompanying drawings. It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.

[0030] Figures 1 to 4 Schematically shown is a compound drill reamer for precision hole machining according to an embodiment of the present utility model. As shown in the figure, the compound drill reamer for precision hole machining includes a cylindrical tool body 01, with a tool head 1 formed at one end of the tool body 01 and a tool shank 2 formed at the other end; it is characterized in that:

[0031] The tool head 1 includes two cutting lips 10 and two main chip flutes 11 formed between the two cutting lips 10. Each cutting lip 10 is respectively provided with a first cutting edge land 101 and a second cutting edge land 102 in the clockwise direction. A secondary chip flute 103 is formed between each group of the first cutting edge land 101 and the second cutting edge land 102. The two cutting lips 10 and the first cutting edge land 101 and the second cutting edge land 102 provided on the two cutting lips 10 are all symmetrically arranged about the cross-sectional center of the tool body 01;

[0032] The height of the radial cross-section at the lower end of the first cutting edge land 101 is lower than the height of the radial cross-section at the lower end of the second cutting edge land 102, and the radial distance of the first cutting edge land 101 relative to the central axis is shorter than the radial distance of the second cutting edge land 102 relative to the central axis, so that the first cutting edge land 101 participates in cutting first to rough-machine the hole, and the second cutting edge land 102 reams and finely machines the hole on the basis of the rough-machined hole. The value H by which the height of the radial cross-section at the lower end of the first cutting edge land 101 is lower than the height of the radial cross-section at the lower end of the second cutting edge land 102 is preferably 0.05 mm - 0.08 mm.

[0033] The cutting lip 10, the first cutting edge land 101, the second cutting edge land 102, the main chip flute 11 and the secondary chip flute 103 all extend helically along the axis of the tool body 01.

[0034] Furthermore, a rear angle face 104 that inclines inwards is provided behind the second cutting edge land 102. Preferably, the included angle between the rear angle face 104 and the radial face is 5° - 7°. The beneficial effect is that by providing the rear angle face 104, sufficient support can be provided while reducing the friction, so as to achieve and realize higher machining accuracy.

[0035] The compound drill reamer for precision hole machining adopts a first cutting edge band 101 and a second cutting edge band 102 integrally arranged on the cutting edge lobe 10. During the rotation of the tool, it always ensures that the first cutting edge band 22 participates in cutting first, playing a rough machining role, and the second cutting edge band 23 can play a reaming role, completing precision hole machining at one time. In addition, a main chip removal groove 11 and a secondary chip removal groove 103 are provided for rapid and effective chip removal. Its beneficial effects are as follows: First, for the compound drill reamer adopting this scheme, there is no need to change the tool, no need to first drill a bottom hole with a drill bit and directly process, so there is no need for a rough machining process, which can greatly improve the processing efficiency. At the same time, there is no need to change and reposition the tool twice, reducing the tool change time, simplifying the processing procedure, reducing the tool library positions, greatly increasing the cutting efficiency, and increasing the equipment utilization rate. Especially when processing steel parts and cast iron parts, it saves costs and improves efficiency, meeting the needs of large-scale production; Second, there is no need to change the tool and no need for multiple positioning, with a consistent machining reference and high product quality; Third, by setting the main chip removal groove 11 and the secondary chip removal groove 103, chips are removed quickly and timely after cutting, the cutting process is stable, the cutting deformation is small, ensuring the surface quality of the drilled hole, and at the same time facilitating multiple grinding, improving the maintenance convenience and service life of the cutting tool; Fourth, the first cutting edge band 101 and the second cutting edge band 102 can also play a role in reducing friction, ensuring the cutting accuracy and cutting speed.

[0036] In multiple groups of repeated tests, the comparison between the compound drill reamer of the present utility model and the traditional process scheme (first rough cutting with a drill bit and then finish machining with a reamer) is as follows:

[0037] Tool selection: The compound drill reamer has 2 cutting edges and a cutting diameter of 8.2 mm;

[0038] The traditional process scheme is a drill bit with 2 cutting edges and a cutting diameter of 8 mm, and a reamer with 6 cutting edges and a cutting diameter of 8.2 mm.

[0039] Cutting speed: The compound drill reamer is 70 m / min; the drill bit is 70 m / min, and the reamer is 40 m / min.

[0040] Feed rate: The compound drill reamer is 380 mm / min; the drill bit is 390 mm / min, and the reamer is 466 mm / min.

[0041] Service life: The compound drill reamer is 50 m; the drill bit is 50 m, and the reamer is 40 m.

[0042] Processing cycle: The compound drill reamer is 65 m; the traditional process scheme is 132 s.

[0043] It can be seen from this that its overall service life is improved, the processing efficiency is significantly improved, increased by more than 50%, greatly increasing the cutting efficiency and the equipment utilization rate.

[0044] Preferably, the width of the first land 101 is 5%-7% of the tool diameter;

[0045] The width of the second land 102 is 1.2%-2.8% of the tool diameter. The beneficial effect is that the two lands with such dimensions reduce friction and can achieve a better cutting effect.

[0046] Furthermore, two internal cooling holes 3 are provided in the tool body 01. The internal cooling holes 3 extend spirally along the axial direction of the tool body 01 and penetrate through the tool shank 2 and the tool tip 1 at both ends, and their spiral arrangement is consistent with the direction of the cutting lips 10. The beneficial effect is that this setting makes it easy for the cutting fluid to enter the drilling position and the heating position, obtaining good cooling quality and ensuring the machining speed and cutting quality.

[0047] Preferably, a tapered transition section 4 is provided between the tool shank 2 and the tool tip 1, and its taper is 30°. The beneficial effect is that this setting reduces the tool stress.

[0048] Preferably, the tool shank 2 is cylindrical or tapered; the tool tip 1 is tapered. The beneficial effect is that the tool shank 2 with such a setting is convenient for clamping, and the tool tip 1 with such a setting is convenient for protecting the quality of the machined hole position.

[0049] Furthermore, an external coating with wear resistance, surface heat insulation, and surface lubrication is formed on the outer surface of the tool tip 1 by coating technology. The external coating is preferably a PVD physical vapor deposition coating. The beneficial effect is that this setting improves the wear resistance, surface heat insulation performance, and surface lubrication performance of the tool, and improves the machining performance, machining quality, and product life of the equipment.

[0050] Furthermore, the tool body 01 is made of cemented carbide of ISO grade K20-30. The beneficial effect is that the tool with such a setting has good mechanical properties and can effectively machine steel parts and cast iron parts.

[0051] The above are only some embodiments of the present invention. For those of ordinary skill in the art, without departing from the creative concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A compound drill reamer for precision hole machining, comprising a cylindrical tool body (01), one end of the tool body (01) forms a tool tip (1) and the other end forms a tool shank (2); characterized in that: The tool tip (1) includes two cutting lips (10) and two main chip flutes (11) formed between the two cutting lips (10). Each cutting lip (10) is respectively provided with a first cutting edge land (101) and a second cutting edge land (102) in the clockwise direction. A chip flute (103) is formed between each set of the first cutting edge land (101) and the second cutting edge land (102). The two cutting lips (10) and the first cutting edge land (101) and the second cutting edge land (102) provided on the two cutting lips (10) are all symmetrically arranged about the cross-sectional center of the tool body (01); The height of the radial cross-section at the lower end of the first cutting edge land (101) is lower than the height of the radial cross-section at the lower end of the second cutting edge land (102), and the radial distance of the first cutting edge land (101) relative to the central axis is shorter than the radial distance of the second cutting edge land (102) relative to the central axis. The first cutting edge land (101) first rough-machines the hole, and the second cutting edge land (102) then reams and finely machines the hole; The cutting lips (10), the first cutting edge land (101), the second cutting edge land (102), the main chip flutes (11) and the chip flutes (103) all extend spirally along the axis of the tool body (01).

2. The composite drill reamer for precision hole machining according to claim 1, wherein The value H by which the height of the radial cross-section at the lower end of the first cutting edge land (101) is lower than the height of the radial cross-section at the lower end of the second cutting edge land (102) is 0.05 mm - 0.08 mm.

3. The composite drill reamer for precision hole machining according to claim 1, characterized in that, A rear angle surface (104) that inclines inward is provided behind the second cutting edge land (102).

4. The composite drill reamer for precision hole machining according to claim 3, characterized in that, The included angle between the rear angle surface (104) and the radial surface is 5° - 7°.

5. A combined drill reamer for precision hole machining according to any one of claims 1 to 4, characterized in that, The width of the first cutting edge land (101) is 5% - 7% of the tool diameter; The width of the second cutting edge land (102) is 1.2% - 2.8% of the tool diameter.

6. A compound drill reamer for precision hole machining according to claim 1, characterized in that, The internal cooling hole (3) of the tool body (01) extends spirally along the axial direction of the tool body (01) and penetrates through the tool shank (2) and the tool tip (1) at both ends, and its spiral arrangement is in the same direction as that of the cutting lips (10).

7. A combined drill reamer for precision hole machining according to claim 1, characterized in that, A tapered transition section (4) with a taper of 30° is further provided between the tool shank (2) and the tool tip (1); Or the tool shank (2) is cylindrical or tapered; the tool tip (1) is tapered.

8. A compound drill reamer for precision hole machining according to claim 1, characterized in that, An outer coating with wear resistance, surface heat insulation and surface lubrication is formed on the outer surface of the tool tip (1) by means of a coating technology.

9. The composite drill reamer for precision hole machining according to claim 8, wherein, The outer coating is a PVD physical vapor deposition coating.

10. A compound drill reamer for precision hole machining according to claim 1, characterized in that, The tool body (01) is made of cemented carbide of ISO grade K20 - 30.

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