Combined blade fine broach for broaching fir-tree type mortise

Abstract

The application discloses a combined blade fine broach for broaching fir-tree type mortise, which comprises a broach body and a broach tooth part, the broach tooth part comprises a profile cutting area and a tooth crest cutting area arranged in sequence along the length direction of the broach body, the profile cutting area is used for broaching the two side profiles of the mortise, the tooth crest cutting area comprises a tooth crest cutting part and a tooth crest shaping part used for broaching the top of the mortise and arranged in sequence along the length direction of the broach head, the tooth crest cutting part is located between the profile cutting area and the tooth crest shaping part, and the tooth crest height of the tooth crest cutting part is higher than the tooth crest height of the profile cutting area. Since the profile cutting area and the tooth crest cutting area of the combined blade fine broach are integrally machined, the machining precision can be guaranteed to be consistent, so that the generation of "tool joint marks" in the broaching process is avoided, and then the mortise is step by step finely machined through the profile cutting area and the tooth crest cutting area, so that the final profile size, machining precision and surface quality of the mortise are guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of processing fir-tree mortise of turbine disk of aero-engine, in particular to a combined blade fine broach for broaching fir-tree mortise. BACKGROUND

[0002] The traditional complete broach design includes rough broach, semi-fine broach, fine broach and profile correction fine broach, wherein the fine broach is divided into two independent fine broaches. Specifically, it includes tooth top fine broach and profile fine broach. When broaching mortise, the tooth top fine broach is used to broach the top of mortise first, and then the profile fine broach is used to broach the two side profiles of mortise. When designing the profile fine broach, in order to avoid the profile fine broach extruding mortise when broaching the tooth top part, causing the tooth top surface to be hardened or scratched, the tooth top of the profile fine broach is designed to be 0.1-0.2mm lower than the tooth top of the tooth top fine broach. Since the tooth top fine broach and the profile fine broach are two independent broaches, it is difficult to ensure the consistency of the machining accuracy when machining mortise, so the joint position of the tooth top fine broach and the profile fine broach is prone to appear joint marks, thereby causing the risk of damage of mortise due to stress concentration. SUMMARY

[0003] The present application provides a combined blade fine broach for broaching fir-tree mortise, to solve the technical problem of how to eliminate joint marks in the process of machining mortise, and ensure the final profile size, machining accuracy and surface quality of mortise.

[0004] According to the combined blade fine broach for broaching fir-tree mortise provided by the present application, the broach includes a broach body and a broach tooth part. The broach body includes a broach seat and a broach head arranged in sequence along the height direction, and the broach seat is connected with the broaching machine through a pressing block. The broach tooth part includes a profile cutting area and a tooth top cutting area arranged in sequence along the length direction of the broach body. The profile cutting area is used to broach the two side profiles of mortise. The tooth top cutting area includes a tooth top cutting part and a tooth top profile correction part used to broach the top of mortise, which are arranged in sequence along the length direction of the broach head. The tooth top cutting part is located between the profile cutting area and the tooth top profile correction part. The tooth top height of the tooth top cutting part is higher than the tooth top height of the profile cutting area.

[0005] Further, the profile cutting area includes a plurality of profile cutting teeth arranged at intervals along the length direction of the broach head. The rake angle of the profile cutting tooth is the included angle between the blade of the profile cutting tooth and the vertical direction. The relief angle of the profile cutting tooth is the angle between the blade of the profile cutting tooth and the horizontal direction. The rake angle γ1 of the profile cutting tooth is 8°-15°, and the relief angle β1 of the profile cutting tooth is 3°-3°30’.

[0006] Further, the rake angle of the tooth tip cutting part is the included angle between the cutting edge of the tooth tip cutting part and the vertical direction, the relief angle of the tooth tip cutting part is the angle between the cutting edge of the tooth tip cutting part and the horizontal direction, the rake angle γ2 of the tooth tip cutting part is 5°-8°, and the relief angle β1 of the tooth tip cutting part is 2°-2°30'.

[0007] Further, the tooth groove depth of the rake angle of the tooth tip cutting part is 2.5mm-3mm.

[0008] Further, the rake angle of the tooth tip cutting part is the included angle between the cutting edge of the tooth tip cutting part and the vertical direction, the relief angle of the tooth tip cutting part is the angle between the cutting edge of the tooth tip cutting part and the horizontal direction, the rake angle γ2 of the tooth tip cutting part is 5°-8°, and the relief angle β1 of the tooth tip cutting part is 2°-2°30'.

[0009] Further, the tooth tip cutting part comprises a first tooth tip cutting tooth and a second tooth tip cutting tooth arranged in sequence along the direction from the profile cutting part to the tooth tip cutting part, the height of the first tooth tip cutting tooth is higher than the height of the profile cutting tooth, and the height difference is 0.1mm-0.2mm.

[0010] Further, the tooth tip cutting part comprises a first tooth tip cutting tooth and a second tooth tip cutting tooth arranged in sequence along the direction from the profile cutting part to the tooth tip cutting part, the height of the first tooth tip cutting tooth is higher than the height of the profile cutting tooth, and the height difference is 0.1mm-0.2mm.

[0011] Further, the interval distance of the adjacent two profile cutting teeth along the length direction of the tool head is 10mm-12mm; the interval distance of the adjacent first tooth tip cutting tooth and the second tooth tip cutting tooth along the length direction of the tool head is 10mm-12mm; and the interval distance of the adjacent two tooth tip shaping teeth along the length direction of the tool head is 10mm-12mm.

[0012] Further, the tooth tip cutting part further comprises a profile tooth located on both sides of the tool head, the rake angle of the profile tooth is the included angle between the cutting edge of the profile tooth and the vertical direction, and the rake angle γ4 of the profile tooth is 0°.

[0013] Further, the included angle a between the profile tooth and the bottom position of the tooth groove of the rake angle of the tooth tip cutting part is 30'-1°.

[0014] The present application has the following beneficial effects:

[0015] The combined blade fine broach for broaching fir-tree type mortise of the present application, the cutter body includes cutter seat and cutter head arranged in sequence along the height direction, the cutter seat is used for connecting with numerical control horizontal side broaching machine, specifically, the cutter seat is clamped and pressed by pressing block so as to be assembled on the broaching machine, the cutter head is provided with cutter tooth part for broaching mortise, specifically, the cutter tooth part includes profile cutting area and tooth top cutting area arranged in sequence along the length direction of the cutter head, the profile cutting area is used for broaching two side profiles of the mortise, the tooth top cutting area is used for broaching the top of the mortise, wherein the tooth top cutting part is used for primary fine machining broaching of the tooth top of the mortise, the tooth top shaping part is used for further fine machining broaching of the tooth top, and when the two side profiles of the mortise are broached in the profile cutting area, in order to ensure the machining precision of the top of the mortise, the top of the mortise still has machining allowance after profile cutting, so the tooth top height of the top cutting part is higher than the tooth top height of the profile cutting area. In specific implementation, the cutter seat and the broaching machine are connected through the pressing block, and then the broaching machine is used to operate the combined blade fine broach to broach the mortise, specifically, the two side profiles of the mortise are first broached in place by the profile cutting area, and then the top of the mortise is fine machined by the tooth top cutting part, so that the top size of the mortise is close to the design size, and finally the top of the mortise is further fine machined by the tooth top shaping part, so that the mortise reaches the final profile size. Through the design scheme, the profile cutting area of the combined blade fine broach broaches the two side profiles of the mortise in place, and the tooth top cutting area of the combined blade fine broach processes the top of the mortise in place. Since the profile cutting area and the tooth top cutting area of the combined blade fine broach are integrally machined, the machining precision can ensure consistency, thereby avoiding the generation of "tool joint marks" in the broaching process, and then the profile cutting area and the tooth top cutting area are used for step-by-step fine machining of the mortise, thereby ensuring the final profile size, machining precision and surface quality of the mortise.

[0016] In addition to the objects, features, and advantages described above, the present application has other objects, features, and advantages. The present application will be further described in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The drawings illustrate one exemplary embodiment of the present application and, together with the description, serve to explain the principles of the present application. In the drawings:

[0018] Figure 1 is a structure schematic view of the combined blade fine broach for broaching fir-tree type mortise of the preferred embodiment of the present application;

[0019] Figure 2 is a structure schematic view of the combined blade fine broach for broaching fir-tree type mortise of the preferred embodiment of the present application; Figure 1

[0020] Figure 3 is a structure sectional view of A-A in Figure 1 ; and ​

[0021] Figure 4 is Figure 1 a structural section view of C-C in

[0022] Figure 5 is Figure 1 a structural section view of D-D in

[0023] Figure 6 is Figure 1 a structural section view of E-E in

[0024] Figure 7 is a structural schematic diagram of the tooth top correction tooth of the preferred embodiment of the present application.

[0025] Legend:

[0026] 100, cutter body; 101, cutter seat; 102, cutter head; 103, V-shaped groove; 104, positioning groove;

[0027] 200, profile cutting area; 201, profile cutting tooth;

[0028] 300, tooth top cutting area; 301, first tooth top cutting tooth; 302, second tooth top cutting tooth; 303, tooth top correction tooth; 304, profile tooth. DETAILED DESCRIPTION

[0029] The embodiments of the present application are described in detail below with reference to the accompanying drawings, but the present application can be implemented in various different ways as defined and covered by the following.

[0030] As shown in Figures 1-3 , the present embodiment provides a combined blade fine broach for broaching fir tree type dowel groove, comprising a cutter body 100 and a cutter tooth part, the cutter body comprises a cutter seat and a cutter head arranged in sequence along the height direction, the cutter seat is connected with the broaching machine through a pressing block, the cutter tooth part comprises a profile cutting area 200 and a tooth top cutting area 300 arranged in sequence along the length direction of the cutter body 100, the profile cutting area 200 is used for broaching the two side profiles of the dowel groove, the tooth top cutting area 300 comprises a tooth top cutting part and a tooth top correction part used for broaching the top of the dowel groove arranged in sequence along the length direction of the cutter head 102, the tooth top cutting part is located between the profile cutting area 200 and the tooth top correction part, the tooth top height of the tooth top cutting part is higher than the tooth top height of the profile cutting area 200.

[0031] In the embodiment, the bottom surface of the tool seat 101 is the bottom reference, one side surface of the tool seat 101 is the side reference, a V-shaped groove for matching the clamping and pressing of the pressing block is arranged on the opposite surface of the side reference surface, the angle of the V-shaped groove is generally 10° and 15°, and the specific case is selected according to the angle of the pressing block on the numerical control horizontal side broaching machine. In order to further stably clamp the tool seat 101, a positioning groove 104 is arranged on the side reference surface to facilitate clamping of the tool seat 101. The tool body 100 includes the tool seat 101 and the tool head 102 arranged in sequence from bottom to top, the tool seat 101 is used to be connected with the numerical control horizontal side broaching machine, specifically, the tool seat 101 is clamped and pressed by the pressing block so as to be assembled on the broaching machine, the tool head 102 is provided with a tool tooth part for broaching the tenon groove, specifically, the tool tooth part includes the profile cutting area 200 and the tooth crest cutting area 300 arranged in sequence along the length direction of the tool head 102, the profile cutting area 200 is used to broach the two side profiles of the tenon groove, and the tooth crest cutting area 300 is used to broach the top of the tenon groove. The tooth crest cutting part is used to initially finish machining broaching of the tooth crest of the tenon groove, and the tooth crest shaping part is used to further finish machining broaching of the tooth crest. When the two side profiles of the tenon groove are broached by the profile cutting area 200, in order to ensure the machining precision of the top of the tenon groove, it is necessary to ensure that the top of the tenon groove still has a machining allowance after profile cutting, so the tooth crest height of the top cutting part is higher than the tooth crest height of the profile cutting area 200.

[0032] The tenon groove before machining is a tenon groove obtained through semi-finish machining, and then the tenon groove is finish machined by using the combined blade finish broach for broaching the longitudinal tenon groove. In specific implementation, the tool seat 101 is connected with the broaching machine by the pressing block, and then the tenon groove is broached by the combined blade finish broach through the operation of the broaching machine. Specifically, the two side profiles of the tenon groove are first broached to position by the profile cutting area 200, and then the top of the tenon groove is finish machined by the tooth crest cutting part, so that the size of the top of the tenon groove is close to the design size, and finally the top of the tenon groove is further finish machined by the tooth crest shaping part, so that the tenon groove reaches the final profile size. Through the design scheme, the two side profiles of the tenon groove are broached to position by the profile cutting area 200 of the combined blade finish broach, and the top of the tenon groove is machined to position by the tooth crest cutting area 300 of the combined blade finish broach. Since the profile cutting area 200 and the tooth crest cutting area 300 of the combined blade finish broach are integrally machined, the machining precision can ensure consistency, thereby avoiding the generation of “tool joint marks” in the broaching process. The tenon groove is further finish machined by the profile cutting area 200 and the tooth crest cutting area 300, thereby ensuring the final profile size, machining precision and surface quality of the tenon groove.

[0033] As Figure 6The profile cutting area 200 includes a plurality of profile cutting teeth 201 spaced apart along the length of the cutter head 102. The rake angle of the profile cutting tooth 201 is the angle between the cutting edge of the profile cutting tooth 201 and the vertical direction, and the clearance angle of the profile cutting tooth 201 is the angle between the cutting edge of the profile cutting tooth 201 and the horizontal direction. The rake angle γ1 of the profile cutting tooth 201 is 8° to 15°, and the clearance angle β1 of the profile cutting tooth 201 is 3° to 3°30'.

[0034] In this embodiment, the rake angle γ1 of the profile cutting tooth 201 is 8° to 15°. The size of the rake angle is related to the stiffness of the profile cutting tooth 201, and the specific size is selected according to the broaching of turbine disks of different materials. Specifically, the lower the hardness of the turbine disk material, the lower the pulling force when broaching the turbine disk will be. The profile cutting tooth 201 needs to be sharp, so a large rake angle and clearance angle can be selected to ensure the sharpness of the profile cutting tooth 201 and the degree of avoidance during cutting. Therefore, the larger the rake angle of the profile cutting tooth 201, the larger the rake angle γ1 should be, but it should not exceed 15°. If the rake angle exceeds 15°, the stiffness of the profile cutting tooth 201 will be too low, which may cause the profile cutting tooth 201 to break during machining or accelerate the wear rate of the profile cutting tooth 201, thereby affecting the tool life.

[0035] Conversely, the higher the hardness of the turbine disk material, the greater the pulling force during broaching. The profile cutting tooth 201 needs sufficient strength, thus requiring a smaller rake angle for the broach. However, the rake angle γ1 cannot be less than 8°. If the rake angle is less than 8°, the metal chips from broaching the turbine disk will be squeezed against the profile cutting tooth 201, causing wear and resulting in tooth edge defects, affecting the broaching quality. The clearance angle β1 of the profile cutting tooth 201 is 3° to 3°30'. When the clearance angle is less than 3°, the tenon groove increases after broaching, reducing the broaching allowance for subsequent tooth tip cutting, which is detrimental to the finishing of subsequent tooth tip cutting. If the clearance angle is greater than 3°30', it is difficult to machine the two sides of the tenon groove to the correct position, failing to meet design requirements.

[0036] like Figure 4 The rake angle of the tooth tip cutting part is the angle between the cutting edge of the tooth tip cutting part and the vertical direction, and the clearance angle of the tooth tip cutting part is the angle between the cutting edge of the tooth tip cutting part and the horizontal direction. The rake angle γ2 of the tooth tip cutting part is 5° to 8°, and the clearance angle β2 of the tooth tip cutting part is 2° to 2°30'.

[0037] In the embodiment, the rake angle γ2 of the tooth tip cutting portion is 5°-8°, since the tooth tip cutting portion is used to machine the top of the mortise, the machining allowance of the top of the mortise required to be broached is small, and in order to better connect with the profile tooth 304 reserved on both sides of the tooth tip cutting portion, the size of the rake angle γ2 and the relief angle β2 of the tooth tip cutting portion is smaller than the size of the rake angle γ1 and the relief angle β1 of the tooth tip cutting portion. In the embodiment, the size of the rake angle γ2 and the relief angle β2 of the tooth tip cutting portion is related to the rigidity of the tooth tip cutting portion, and the specific size is selected according to the broaching of the turbine disc of different materials. Specifically, the lower the hardness of the turbine disc material, the smaller the broaching force when the turbine disc is broached, the tooth edge of the tooth tip cutting portion requires to be sharp, and the large rake angle and the large relief angle can be selected to ensure the sharpness of the tooth edge of the tooth tip cutting portion and the avoidance degree during cutting. The larger the rake angle of the tooth tip cutting portion, but the rake angle γ2 cannot exceed 8°, if the rake angle exceeds 8°, the rigidity of the tooth tip cutting portion is too low, which is easy to cause the tooth tip cutting portion to collapse during machining or accelerate the wear speed of the tooth tip cutting portion, thereby affecting the service life of the tool.

[0038] Conversely, the higher the hardness of the turbine disc material, the larger the broaching force when the turbine disc is broached, and the tooth tip cutting portion requires sufficient strength, so the smaller the rake angle of the broach is selected, but the rake angle γ2 cannot be less than 5°, if the rake angle is less than 5°, the iron filings after the turbine disc is broached will be extruded with the tooth tip cutting portion, thereby wearing the tooth tip cutting portion, causing the tooth edge defect, and affecting the broaching quality of the tool. The relief angle β2 of the tooth tip cutting portion is 2°-2°30', when the relief angle β2 is less than 2°, after broaching, the broaching allowance of the top of the mortise is reduced, thereby being not conducive to the finish machining of the tooth tip shaping portion, if the relief angle β2 is greater than 2°30', it is difficult to machine the profile of the two sides of the mortise in place, and the design requirements cannot be met.

[0039] As Figure 7 described, the rake angle of the tooth tip shaping portion is the included angle between the cutting edge of the tooth tip shaping portion and the vertical direction, the relief angle of the tooth tip shaping portion is the angle between the cutting edge of the tooth tip shaping portion and the horizontal direction, the rake angle γ3 of the tooth tip shaping portion is 5°-8°, and the relief angle β3 of the tooth tip shaping portion is 1°-1°30'.

[0040] In the embodiment, the rake angle γ3 of the tooth tip shaping portion is 5°-8°, which is consistent with the size of the rake angle γ2 of the tooth tip cutting portion, in order to improve the broaching accuracy, the relief angle β3 of the tooth tip shaping portion is smaller than the relief angle β2 of the tooth tip cutting portion, in this way, the sharpness of the tooth edge of the tooth tip shaping portion is increased, which is more conducive to the broaching of the top of the mortise, so as to improve the accuracy of the mortise and make the size of the mortise more easily machined to the design size.

[0041] Further, the addendum cutting portion comprises a first addendum cutting tooth 301 and a second addendum cutting tooth 302 arranged in sequence along the direction from the profile cutting area 200 to the addendum cutting area 300, the height of the first addendum cutting tooth 301 is higher than the height of the profile cutting tooth 201, and the height difference is 0.1mm-0.2mm. In the embodiment, the height of the first addendum cutting tooth 301 is 0.1mm-0.2mm higher than the height of the profile cutting tooth 201, so that the profile cutting tooth 201 can only perform finish machining on the two side profiles of the mortise during finish machining, so that the two side profiles of the mortise are machined to the design size, but the top of the profile cutting tooth 201 does not contact the top of the mortise, so as to ensure that the addendum cutting tooth has a 0.03mm-0.05mm broaching amount when machining the addendum. In the case that the size of the first addendum cutting tooth 301 is unchanged, if the height difference between the first addendum cutting tooth 301 and the profile cutting tooth 201 is less than 0.1mm, the profile cutting tooth 201 will broach the top of the mortise, so that the machining allowance of the top of the mortise is reduced, thereby reducing the broaching amount of the first addendum cutting tooth 301, and affecting the machining precision of the top of the mortise; if the height difference between the first addendum cutting tooth 301 and the profile cutting tooth 201 is greater than 0.2mm, the overall size of the profile cutting tooth 201 will be affected, so that the profile cutting tooth 201 is difficult to machine the two side profiles of the mortise to the design size.

[0042] Further, the addendum correction portion comprises a plurality of addendum correction teeth 303 arranged in sequence along the direction from the profile cutting area 200 to the addendum cutting area 300, the height of the second addendum cutting tooth 302 is higher than the height of the first addendum cutting tooth 301, and the height difference is 0.02-0.05mm, the height of the addendum correction tooth 303 is higher than the height of the second addendum cutting tooth 302, and the height difference is 0.02-0.05mm.

[0043] In the embodiment, the number of the tooth tip correction teeth 303 is three, and the distance between every two tooth tip correction teeth 303 is determined according to the thickness of the machined part, and is usually 1.25-1.35 times of the thickness of the part, so that only one single tooth tip correction tooth 303 works at a time when each tooth tip correction tooth 303 works, and a relief distance of 5-8 mm is reserved when every two adjacent tooth tip correction teeth 303 work. The tooth tip height of the second tooth tip cutting tooth 302 is 0.02-0.05 mm higher than the height of the first tooth tip cutting tooth 301, and the tooth tip height of the tooth tip correction tooth 303 is 0.02-0.05 mm higher than the height of the second tooth tip cutting tooth 302. This setting gradually transitions when broaching the top of the mortise and tenon joint, on the one hand, ensures the broaching quality and precision, and gradually processes the top of the mortise and tenon joint to close to the design size by the first tooth tip cutting tooth 301 and the second tooth tip cutting tooth 302, and further processes by the tooth tip correction part, so that the tooth tip correction part processes the top of the mortise and tenon joint to meet the design size, thereby ensuring the final profile size, machining precision and surface quality of the mortise and tenon joint. On the other hand, the first tooth tip cutting tooth 301, the second tooth tip cutting tooth 302 and the tooth tip correction tooth 303 are designed in the form of gradually increasing height, and the broaching work of the top of the mortise and tenon joint is divided into multiple stages, thereby reducing the wear degree of the first tooth tip cutting tooth 301, the second tooth tip cutting tooth 302 and the tooth tip correction tooth 303, and improving the service life of the first tooth tip cutting tooth 301, the second tooth tip cutting tooth 302 and the tooth tip correction tooth 303.

[0044] Further, the interval distance of every two adjacent profile cutting teeth 201 along the length direction of the tool head 102 is 10-12 mm; the interval distance of the adjacent first tooth tip cutting tooth 301 and the second tooth tip cutting tooth 302 along the length direction of the tool head 102 is 10-12 mm, and the interval distance of every two adjacent tooth tip correction teeth 303 along the length direction of the tool head 102 is 10-12 mm. In the embodiment, the interval distance of every two profile cutting teeth 201, the interval distance of the first tooth tip cutting tooth 301 and the adjacent profile cutting tooth 201, and the interval distance of the first tooth tip cutting tooth 301 and the second tooth tip cutting tooth 302 are determined according to the thickness of the broached part, in order to ensure that 2-3 cutting teeth participate in broaching, the interval distance of every two cutting teeth is 10-12 mm. When the interval distance of every two cutting teeth is less than 10 mm, the cutting teeth are too compact, and more than three cutting teeth may work at the same time, and when the interval distance of every two cutting teeth is greater than 12 mm, the cutting teeth are too dispersed, and only a single cutting tooth may participate in broaching.

[0045] Reference Figure 5The tooth top cutting area 300 further comprises profile teeth 304 on both sides of the tool head 102, the rake angle of the profile teeth is the included angle between the cutting edge of the profile teeth and the vertical direction, and the rake angle γ4 of the profile teeth 304 is 0°. In the embodiment, the rake angle of the profile teeth 304 is designed to be 0° to avoid the collision of the profile teeth 304 on both sides with the two side profiles of the machined mortise, and if the rake angle γ4 of the profile teeth 304 has an angle, the profile teeth 304 will collide with the mortise and appear concave damage when the mortise is ground.

[0046] Further, the depth of the tooth groove of the rake angle of the tooth top cutting area is 2.5mm-3mm. In the embodiment, when the depth of the tooth groove is less than 2.5mm, the broaching depth is not enough to make the top of the mortise difficult to be machined in place, and when the depth of the tooth groove is greater than 3mm, the rigidity of the tooth of the tooth top broaching area will be reduced, so that the fine broach is easy to break when used.

[0047] Further, the included angle a between the profile teeth 304 and the bottom position of the tooth groove of the rake angle of the tooth top cutting area 300 is 30'-1°. In the embodiment, the above setting is to avoid the rake angle of the tooth top cutting area 300 coinciding with the rake angle of the profile teeth 304 on both sides, so that the profile teeth 304 can better avoid the two side profiles which do not participate in the broaching of the mortise when the tooth top cutting area 300 grinds the mortise.

[0048] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A combined blade fine broach for broaching fir-tree mortises, characterized in that, The utility model relates to a combined blade precision broach, comprising: a tool body (100) comprising a tool seat (101) and a tool head (102) arranged in sequence along a height direction, the tool seat (101) being connected with a broaching machine through a pressing block; a tool tooth part arranged on the tool head (102), the tool tooth part comprising a profile cutting area (200) and a tooth crest cutting area (300) arranged in sequence along a length direction of the tool head (102), the profile cutting area (200) being used for broaching two side profiles of a tenon groove, the tooth crest cutting area (300) comprising a tooth crest cutting part used for broaching a top part of the tenon groove and a tooth crest shaping part used for improving broaching precision of the top part of the tenon groove and arranged in sequence along the length direction of the tool head (102), the tooth crest cutting part being located between the profile cutting area (200) and the tooth crest shaping part, a tooth crest height of the tooth crest cutting part being higher than a tooth crest height of the profile cutting area (200), the profile cutting area (200) and the tooth crest cutting area (300) of the combined blade precision broach being integrally machined and formed, the profile cutting area (200) comprising a plurality of profile cutting teeth (201) arranged at intervals along the length direction of the tool head (102), a rake angle of the profile cutting tooth (201) being an included angle between a blade of the profile cutting tooth (201) and a vertical direction, a relief angle of the profile cutting tooth (201) being an angle between the blade of the profile cutting tooth (201) and a horizontal direction, the rake angle Y1 of the profile cutting tooth (201) being 8-15 DEG, and the relief angle beta1 of the profile cutting tooth (201) being 3-3 DEG 30', the tooth crest cutting part comprising a first tooth crest cutting tooth (301) and a second tooth crest cutting tooth (302) arranged in sequence along a direction of the profile cutting area (200) towards the tooth crest cutting area (300), a height of the first tooth crest cutting tooth (301) being higher than a height of the profile cutting tooth (201), and a height difference being 0.1-0.2 mm, the tooth crest shaping part comprising a plurality of tooth crest shaping teeth (303) arranged in sequence along the direction of the profile cutting area (200) towards the tooth crest cutting area (300), a height of the second tooth crest cutting tooth (302) being higher than a height of the first tooth crest cutting tooth (301), and a height difference being 0.02-0.05 mm, and a height of the tooth crest shaping tooth (303) being higher than a height of the second tooth crest cutting tooth (302), and a height difference being 0.02-0.05 mm.

2. The combined blade finish broach for broaching fir-tree slot according to claim 1, wherein A rake angle of the tooth crest cutting part is an included angle between a blade of the tooth crest cutting part and a vertical direction, a relief angle of the tooth crest cutting part is an angle between the blade of the tooth crest cutting part and a horizontal direction, the rake angle gamma2 of the tooth crest cutting part being 5-8 DEG, and the relief angle beta1 of the tooth crest cutting part being 2-2 DEG 30'.

3. The combined blade finish broach for broaching fir-tree slot according to claim 2, wherein A tooth groove depth of the rake angle of the tooth crest cutting part is 2.5-3 mm.

4. The combined blade finish broach for broaching fir-tree slot according to claim 1, wherein The rake angle of the tooth tip correction part is the included angle between the cutting edge of the tooth tip correction part and the vertical direction, the relief angle of the tooth tip correction part is the angle between the cutting edge of the tooth tip correction part and the horizontal direction, the rake angle γ3 of the tooth tip correction part is 5°-8°, and the relief angle β3 of the tooth tip correction part is 1°-1°30'.

5. The combined blade finish broach for broaching fir-tree slot according to claim 1, wherein The interval distance of two adjacent profile cutting teeth (201) along the length direction of the cutter head (102) is 10mm-12mm; the interval distance of the adjacent first tooth tip cutting tooth (301) and the second tooth tip cutting tooth (302) along the length direction of the cutter head (102) is 10mm-12mm; and the interval distance of two adjacent tooth tip correction teeth (303) along the length direction of the cutter head (102) is 10mm-12mm.

6. The combined blade finish broach for broaching fir-tree slot according to claim 1, wherein The tooth tip cutting area (300) further comprises profile teeth (304) located on both sides of the cutter head (102), the rake angle of the profile teeth (304) is the included angle between the cutting edge of the profile teeth (304) and the vertical direction, and the rake angle γ4 of the profile teeth (304) is 0°.

7. The combined blade finish broach for broaching fir-tree slot according to claim 6, characterized in that, The included angle a between the profile teeth (304) and the bottom position of the tooth groove of the rake angle of the tooth tip cutting area (300) is 30'-1°.

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