CN108098025B - Reaming cutter for processing ultra-short stepped hole - Google Patents

Abstract

The invention provides a reaming cutter for processing ultra-short stepped holes, which can solve the problems of high processing difficulty, low precision, and easy measurement error of reaming forming cutters for ultra-short multi-step formed holes with a step length less than 3 mm. . The cutter body is a stepped cylinder coaxial with the tool handle; the stepped cylinder includes a first cylinder and a second cylinder connected concentrically, the rear end of the second cylinder is concentrically connected to the tool handle, and the outer peripheral surface of the first cylinder There are four main chip removal grooves and four auxiliary chip removal grooves, and the four main chip removal grooves and the four auxiliary chip removal grooves are arranged at intervals along the circumferential direction and extend backward to the second cylinder at the same time, so that on the stepped cylinder, Eight blade teeth are formed on the outer peripheral surface. The eight blade teeth include four first blade teeth and four second blade teeth. Among them, the blade teeth located on the clockwise side of the main chip removal groove are the first blade teeth, and the counter teeth are the first blade teeth. The blade tooth on one side in the clockwise direction is the second blade tooth, and the first blade tooth and the second blade tooth each include a first cylindrical part and a second cylindrical part.

Description

Hole enlarging tool for ultra-short step hole machining

Technical field

The present invention relates to the field of cutting tools for metal cutting, specifically a hole enlarging tool used for processing ultra-short step holes.

Background technique

With the widespread use of CNC machine tools and machining centers, many process steps in the mechanical field can be concentrated on the same equipment, greatly improving the machining efficiency; and the continuous application of composite cutting tools has also greatly improved the use efficiency of CNC machine tools and machining centers, further It speeds up the production cycle and effectively reduces the cost of a single piece; especially the processing of complex multi-step molding contours has higher requirements on the production cycle.

Currently, for the processing of forming holes with complex structures, many related dimensions, and high precision, in order to improve efficiency, a step drill is usually used to process a step base hole, and then a step reamer is used to ream the step base hole to meet the molding requirements. One-time shaping of the contour. However, for the expansion processing of ultra-short multi-step formed holes with a step length less than 3mm, especially for the expansion processing of stepped blind holes, since the step length does not exceed 3mm, the processing of the step reaming tool is difficult; at the same time, due to the step expansion There is root clearance at the step transition of the hole cutter, which results in a small debugging margin and can easily lead to debugging and scrapping; and because the dimensional tolerance of the step hole chamfer of the part is tight, it is difficult to ensure the processing accuracy during manufacturing, especially at the step chamfer. There is a grinding wheel fillet R, as shown in Figures 6 and 7. Therefore, its measurement is difficult and easy to use, causing measurement errors. Therefore, it cannot meet the accuracy requirements of the contour dimensions of the part. II in Figure 6 is a traditional step reaming tool; in addition, When grinding the traditional step reaming tool after use, the first step must be removed before grinding, so the tool material is wasted seriously and the tool cost is high. In view of this, for the hole expansion processing of this kind of ultra-short multi-step formed holes, in order to ensure the processing accuracy and avoid measurement errors, it is often only possible to process the step holes separately first and then use a chamfering tool to process the step chamfers separately. However, this is not good for The accuracy requirements of machine tools are extremely high, which will greatly extend the production cycle and reduce processing efficiency.

Contents of the invention

In response to the above problems, the present invention provides a reaming cutter for ultra-short step hole processing, which can solve the problem that the reaming forming cutter for ultra-short multi-step formed holes with a step length less than 3 mm is difficult to process, has low precision, and is extremely easy to process. Problems causing errors in debugging measurements.

The technical solution is a reaming cutter for ultra-short step hole processing, which includes a cutter body and a cutter handle. The cutter handle is a cylinder, and the cutter body is a step coaxial with the cutter handle. Cylinder, characterized in that: the stepped cylinder includes a concentrically connected first cylinder with a diameter D1 and a second cylinder with a diameter D2 and D1<D2, and the rear end of the second cylinder is concentric with the tool holder. Integrated connection, the first cylinder is used for enlarging the front end hole, the second cylinder is used for enlarging the rear end hole and step chamfering forming, the outer circumferential surface of the first cylinder is provided with four rows The main chip groove and the four auxiliary chip removal grooves are arranged at intervals along the circumferential direction and extend backward to the second cylinder at the same time, so that on the stepped cylinder Eight blade teeth are formed on the outer circumferential surface of the chip. The eight blade teeth include four first blade teeth and four second blade teeth. The blade teeth located on the clockwise side of the main chip removal groove are the The first blade teeth and the blade teeth on the counterclockwise side are the second blade teeth. The four first blade teeth and the four second blade teeth are all arranged symmetrically with the axis center line in pairs. Each of the first blade tooth and the second blade tooth includes a first cylindrical portion and a second cylindrical portion.

Further, the first cylindrical portion of the four second blade teeth is provided with a guide edge on the tooth back on one side of the main chip removal groove, and the front end of the guide edge is provided with an end chamfer. The tooth heights of the first cylindrical portions of each of the first cutting teeth are smaller than the tooth heights of the first cylindrical portions of the four second cutting teeth.

Further, the guide edge extends rearward to the second cylindrical portion of the second tooth.

Further, the tooth back of the second cylindrical part of the second cutting tooth is radially thinned into an arc surface from the rear end to the front end, and the tooth height of the second cylindrical part of the second cutting tooth is the same as that of the first cylindrical part. The tooth heights are equal and connected into one.

Further, among the four first cutting teeth, the second cylindrical portion of a pair of first cutting teeth is transitionally connected to the first cylindrical portion through a step angle, and two of the step angles are located in the auxiliary chip removal groove. A first land is provided on one side to form two chamfered cutting edges, and the second cylindrical portion of the other pair of first teeth is located on one side of the chip removal auxiliary groove and is respectively provided with a second land to form two enlarged edges. Hole cutting edge.

Further, the core thickness of the main chip removal groove is φa=0.45D1～0.65D1.

Further, the core thickness of the auxiliary chip removal groove is φb=0.75D1～0.85D1.

The beneficial effect of the present invention is that it can meet the ultra-short, complex, multi-step reaming process, especially for ultra-short step reaming drills when the step length is less than 3 mm, it can reduce the manufacturing scrap rate and manufacturing difficulty; In addition, four main chip removal grooves and four auxiliary chip removal grooves are spaced on the stepped cylinder to form centrally symmetrical four first cutting teeth and four second cutting teeth at intervals on the outer circumferential surface of the stepped cylinder. , and the first and second cutting teeth both include the first cylindrical part and the second cylindrical part, so that the tool can complete the step hole expansion forming and step chamfering forming in a single feed, greatly shortening the production cycle and improving processing. Efficiency; in addition, using the processing of the present invention, the molding size is determined by the tool, so it can ensure that the dimensional contour is guaranteed in one process, and has little dependence on the accuracy of the machine tool.

Description of the drawings

Figure 1 is a schematic structural diagram of a hole enlarging tool used for processing ultra-short step holes according to the present invention;

Figure 2 is an enlarged structural diagram of Figure 1 looking from the right;

Figure 3 is a schematic three-dimensional structural diagram of the reaming tool used for processing ultra-short step holes according to the present invention;

Figure 4 is a schematic diagram of using the reaming tool for ultra-short step hole processing according to the present invention to chamfer the workpiece;

Figure 5 is a schematic diagram of the enlarged structure in the A-A direction in Figure 4;

Figure 6 is a schematic diagram of using a conventional step reamer to chamfer and ream the workpiece;

Figure 7 is an enlarged structural diagram of the grinding wheel R angle at B in Figure 6.

Reference signs: 10-cutter body, 11-first cylinder, 12-second cylinder, 13-main chip removal groove, 14-auxiliary chip removal groove, 15-first tooth, 151-th of the first tooth A cylindrical part, 152-the second cylindrical part of the first tooth, 15a-the first tooth, 152a-the second cylindrical part of the first tooth, 153-step angle, 15b-the first tooth, 152b-th The second cylindrical part of a tooth, 16-second tooth, 17-guide land, 171-end chamfer, 18-first land, 19-second land, 20-tool handle, 30-workpiece , 31-chamfering, 32-molding surface.

Detailed ways

Referring to Figures 1 and 2, the reaming cutter I used for ultra-short step hole processing of the present invention includes a cutter body 10 and a cutter handle 20. The cutter handle 20 is a cylinder, and the cutter body 10 is a coaxial shaft with the cutter handle. The stepped cylinder of the line; the stepped cylinder includes a concentrically connected first cylinder 11 with a diameter D1 and a second cylinder 12 with a diameter D2 and D1<D2. The rear end of the second cylinder is concentrically connected to the tool handle 20. One cylinder 11 is used for enlarging the front end hole, and the second cylinder 12 is used for enlarging the rear end hole and step chamfering. The outer peripheral surface of the first cylinder 11 is provided with four main chip removal grooves 13 and four rows. The auxiliary chip groove 14 and the four main chip removal grooves 13 and the four auxiliary chip removal grooves 14 are arranged at intervals in the circumferential direction and extend backward to the second cylinder 12, thereby forming eight edges on the outer peripheral surface of the stepped cylinder. teeth, the core thickness of the chip removal main groove 13 is φa=0.45D1~0.65D1, the core thickness of the chip removal auxiliary groove 14 is φb=0.75D1~0.85D1; the eight cutting teeth include four first cutting teeth 15 and four second cutting teeth. Two cutting teeth 16, in which the clockwise end of each main chip removal groove 13 forms a first cutting tooth 15, and the counterclockwise end forms a second cutting tooth 16, thereby forming mutual intervals on the outer peripheral surface of the stepped cylinder. There are four first blade teeth 15 and four second blade teeth 16. The four first blade teeth 15 and the four second blade teeth 16 are arranged symmetrically in pairs with respect to the axis center line. The first blade teeth 15 include the A cylindrical part 151 and a second cylindrical part 152, the second tooth 16 includes a first cylindrical part 161 and a second cylindrical part 162.

As shown in Figure 3, the first cylindrical portion 161 of the four second blade teeth 16 is provided with a guide edge 17 on the tooth back on one side of the main chip removal groove 13, and the front end of the guide edge 17 is provided with an end chamfer 171. The tooth heights of the first cylindrical portions 151 of the four first blade teeth 15 are all smaller than the tooth heights of the first cylindrical portions 161 of the four second blade teeth 16, so the first cylindrical portions 151 of the first blade teeth 15 do not participate. When the front end hole is expanded and formed, only the first cylindrical portion 161 of the four second teeth 16 participates in the expansion and forming cutting of the front end hole, and the guide land 17 is used as the cutting edge when the end chamfer 171 is used for expansion cutting. It plays an effective guiding and supporting role; and the guide blade 17 extends backward to the second cylindrical part 162 of the second tooth 16, so the extension of the guide blade 17 can increase the number of regrinding times of the reaming knife and improve the cost performance; The tooth back of the second cylindrical portion 162 of the second blade tooth 16 is radially thinned from the rear end to the front end into an arc-shaped surface with a diameter D3. The tooth heights are equal and connected into one body, that is, D3 is equal to the diameter D1 of the first cylinder 11, which can provide enough space for the rearward extension of the guide land 17 after grinding of the reamer. The tooth back of the cylindrical part 162 is radially thinned from the rear end to the front part, so that the tooth height of the second cylindrical part 162 of the second blade tooth 16 is smaller than the tooth height of the second cylindrical part 152 of the first blade tooth 15 , that is, four The second cylindrical portion 162 of the second cutting tooth 16 does not participate in the enlarging and forming process of the rear end hole.

Among the four first cutting teeth 15 , the second cylindrical portion 152 a of a pair of the first cutting teeth 15 a is transitionally connected to the first cylindrical portion 151 through a step angle 153 , and the two step angles 153 are located on one side of the chip removal auxiliary groove 14 A first land 18 is provided to form two chamfered cutting edges, see Figure 3, for forming a chamfer 31 at the step transition of the step hole in the workpiece 30, see Figures 4 and 5; another pair of first blade teeth The second cylindrical portion 152b of 15b is located on one side of the chip removal auxiliary groove 14 and is respectively provided with a second land 19 to form two reaming cutting edges, which are used to form the reaming molding of the step hole forming surface 32 of the workpiece; in Figure 4, Ⅰ is a schematic diagram of the reamer drill of the present invention. Since the chamfering cutting edge and the reaming cutting edge are respectively provided on different cutting teeth 15a and 15b, the integrity of the stepped hole contour of the workpiece after processing can be ensured. See Figure 1. θ in Figure 1 is the angle between two step angles 153.

The front end of the guide land 17 is provided with an end chamfer 171, which is located on the second blade tooth 16. Therefore, it has no structural connection with the first land 18 and the second land 19, ensuring the integrity of the chamfer 171, so that The regrinding of the reamer drill no longer needs to remove the first step, and can be directly regrinded; and while ensuring the diameter, the number of regrinding times can be increased by 5-8 times, thereby effectively improving the cost performance of the tool and reducing the tool cost.

The specific implementation of the present invention has been described in detail above, but the content is only the preferred embodiment of the present invention and cannot be considered to limit the implementation scope of the present invention. All equivalent changes and improvements made within the scope of the invention shall still fall within the scope of the patent of the invention.

Claims (4)

1. A reaming cutter for ultra-short step hole processing, which includes a cutter body (10) and a cutter handle (20). The cutter handle (20) is a cylinder, and the cutter body (10) is a cylinder. The tool holder (20) is a coaxial stepped cylinder, characterized in that: the stepped cylinder includes a concentrically connected first cylinder (11) with a diameter D1 and a second cylinder (12) with a diameter D2, and D1<D2, the rear end of the second cylinder is concentrically connected to the tool holder (20), the first cylinder (11) is used for enlarging the front end hole, and the second cylinder (12) is For the enlarging and step chamfering forming of the rear end hole, four main chip removal grooves (13) and four auxiliary chip removal grooves (14) are provided on the outer peripheral surface of the first cylinder (11), and the four chip removal grooves (14) are provided on the outer peripheral surface of the first cylinder (11). The main chip flute (13) and the four auxiliary chip flutes (14) are arranged at intervals along the circumferential direction and extend backward to the second cylinder (12) at the same time, thereby forming a formation on the outer peripheral surface of the stepped cylinder. Eight blade teeth, the eight blade teeth include four first blade teeth (15) and four second blade teeth (16), among which the one located on the clockwise side of the main chip removal groove (13) The blade teeth are the first blade teeth (15), the blade teeth on the counterclockwise side are the second blade teeth (16), the four first blade teeth (15), and the four second blade teeth (16) are arranged symmetrically with respect to the axis center line. The first blade teeth (15) and the second blade teeth (16) each include a first cylindrical part (151, 161) and a second cylindrical part (152, 161). 162); The first cylindrical portion (161) of the four second cutting teeth (16) is provided with a guide edge (17) on the tooth back on one side of the main chip removal groove (13), and the guide edge The front end of (17) is provided with an end chamfer (171), and the tooth heights of the first cylindrical parts (151) of the four first blade teeth (15) are all smaller than the tooth heights of the four second blade teeth (16). The tooth height of the first cylindrical portion (161); The guide land (17) extends rearward to the second cylindrical portion (162) of the second tooth (16); The tooth back of the second cylindrical portion (162) of the second cutting tooth (16) is radially thinned into an arc surface from the rear end to the front end, and the second cylindrical portion (162) of the second cutting tooth (16) ) has the same height as the teeth of the first cylindrical part (161) and is connected into one body. 2. The reaming cutter for ultra-short step hole processing according to claim 1, characterized in that: among the four first cutting teeth (15), the second one of a pair of first cutting teeth (15a) The cylindrical part (152a) and the first cylindrical part (151) are transitionally connected through a step angle (153), and the two step angles (153) are provided with a first edge on one side of the auxiliary chip removal groove (14) (18) Two chamfered cutting edges are thus formed, and the second cylindrical portion (152b) of the other pair of first teeth (15b) is located on one side of the chip removal auxiliary groove (14) and is respectively provided with a second edge land ( 19) Thus forming two reaming cutting edges. 3. The reaming tool for ultra-short step hole processing according to claim 2, characterized in that: the core thickness of the main chip removal groove (13) is φa=0.45D1~0.65D1. 4. The reaming cutter for processing ultra-short step holes according to claim 3, characterized in that: the core thickness of the auxiliary chip removal groove (14) is φb=0.75D1~0.85D1.