Combined broach

Abstract

The utility model provides a combined broach which comprises a broach body, a front handle, a rear handle, a front handle hole, a rear handle hole, a broach body front end hole and a broach body rear end hole, the broach body is in a hollow cylinder shape, the broach body front end hole and the broach body rear end hole are formed in the front end face and the rear end face of the broach body respectively, and the broach body front end hole and the broach body rear end hole are communicated with the broach body front end hole. The front end hole and the rear end hole of the cutter body are through holes and are communicated with the hollow inner cavity of the cutter body; the front handle and the rear handle are cylinders with the two ends different in diameter, the end with the smaller diameter is used for being inserted into an inner cavity of the cutter body, and the end with the larger diameter is exposed out of the cutter body and used for being connected with a machine tool or a tool. The front handle hole and the rear handle hole are formed in the ends, with the large diameter, of the front handle and the rear handle respectively, the front handle hole and the rear handle hole are through holes penetrating through the handle body, one ends of the front handle hole and the rear handle hole are communicated with the outside, and the other ends of the front handle hole and the rear handle hole are communicated with the small-diameter multi-end face of the handle body.

Description

[Technical field]

[0001] The utility model relates to the technical field of broaches, in particular to a combined broach. [Background technology]

[0002] Combined broach is a common machining tool, widely used in turning, drilling, reaming and other processes. Traditional combined broaches usually consist of three main parts: tool body, front handle and rear handle. Among them, the tool body is the most critical functional component, and the front and rear handles mainly play the role of connection and force transmission.

[0003] In traditional designs, the cutter body is usually a hollow cylindrical structure with a cylindrical inner cavity. The front and rear handles are also cylindrical, with a smaller diameter at one end, which is used to insert into the inner cavity of the cutter body and cooperate with it. The other end of the front and rear handles has a larger diameter and is used to connect to the machine tool or tooling to transmit cutting force and torque.

[0004] During assembly, the front and rear handles are inserted from both ends of the knife body, meet in the middle of the knife body, and are fixed to the knife body by means of threads, bayonet, etc. This design has a simple structure and is easy to process and assemble, so it is widely used in actual production.

[0005] Although the traditional combined broach design is relatively mature, there are still some problems in actual use, which are mainly reflected in the following two aspects:

[0006] 1. Difficult to assemble:

[0007] Since the inner cavity of the cutter body is not connected to the outside world, the air in the inner cavity will be compressed when assembling the front and rear handles, generating a large back pressure, which hinders the insertion of the handle body. Especially when the handle body and the cutter body are tightly matched, the assembly process requires a large force, and improper operation may damage the cutter.

[0008] In addition, when the length of the blade is large, the volume of the compressed air in the inner cavity will also increase, and the assembly resistance will further increase. This not only affects the assembly efficiency, but also brings inconvenience to the operator.

[0009] 2. Poor heat dissipation:

[0010] When using a combined broach, a large amount of heat will be generated in the cutting area of ​​the tool body. Since the inner cavity of the tool body is not connected to the outside world, the heat is difficult to dissipate in time and is easily accumulated inside the tool body, causing the temperature to continue to rise.

[0011] The temperature rise will cause thermal expansion of the tool body material, resulting in changes in the tool geometry, which in turn affects the machining accuracy. In addition, excessive temperature will soften the tool body material, accelerate tool wear, and shorten its service life.

[0012] Especially under high-speed and heavy-load processing conditions, the tool generates more heat and the heat dissipation problem becomes more prominent. If the heat dissipation problem cannot be effectively solved, the application range and processing performance of the combined broach will be greatly limited. [Contents of the utility model]

[0013] In view of the deficiencies in the prior art, the purpose of the present application is to provide a combined broach that solves the problems of difficult assembly and poor heat dissipation.

[0014] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0015] A combined broach, comprising:

[0016] The broach body, the front handle and the rear handle, wherein:

[0017] The broach body is a cylindrical structure, and the front handle and the rear handle are respectively fixedly connected to the broach body.

[0018] Optionally, a through inner hole is provided inside the broach body, and a plurality of threaded holes are processed on two end faces of the broach body, and the plurality of threaded holes are distributed in a circumferential array;

[0019] One end of the front handle and / or the rear handle is a cylindrical structure, the size of which matches the inner hole of the broach body, and the other end is a cylindrical structure, and a through hole corresponding to the threaded hole of the broach body is processed on the end surface;

[0020] The combined broach further comprises screws, which sequentially pass through the through holes of the front handle and / or the rear handle and the corresponding threaded holes on the broach body, so that the front handle and the rear handle are fixedly connected to the broach body.

[0021] Optionally, a through hole is respectively provided on the front handle and the rear handle, which are defined as the front handle hole and the rear handle hole respectively, wherein the front handle hole and the rear handle hole are connected to the hollow inner cavity of the broach body.

[0022] Optionally, one end of the front handle and the rear handle is a threaded portion, and a flat surface is processed on the extension of the threaded portion, which are respectively defined as the front handle flat and the rear handle flat.

[0023] Optionally, the front handle flat and the rear handle flat are flat cylinders, or polygonal cylinders.

[0024] The utility model also provides a combined broach, comprising:

[0025] The knife body, the front handle, the rear handle, the front handle hole, the rear handle hole, the front end hole of the knife body and the rear end hole of the knife body, wherein:

[0026] The blade body is in the shape of a hollow cylinder, the front end hole and the rear end hole of the blade body are respectively arranged on the front end face and the rear end face of the blade body, and the front end hole and the rear end hole of the blade body are through holes, connecting the hollow inner cavity of the blade body;

[0027] The front handle and the rear handle are cylinders with different diameters at both ends, the end with a smaller diameter is used to be inserted into the inner cavity of the tool body, and the end with a larger diameter is exposed outside the tool body and is used to connect to a machine tool or tooling;

[0028] The front handle hole and the rear handle hole are respectively arranged at the ends of the front handle and the rear handle with larger diameters, and the front handle hole and the rear handle hole are through holes that penetrate the handle body, one end of which is connected to the outside world and the other end of which is connected to the smaller diameter multi-end surface of the handle body.

[0029] Optionally, the smaller diameter end of the front handle is inserted into the front end hole of the blade body, and the smaller diameter end of the rear handle is inserted into the rear end hole of the blade body, and they merge in the middle of the inner cavity of the blade body.

[0030] Optionally, the front handle hole is arranged at an end of the front handle with a larger diameter and is located at the center of the end surface;

[0031] The shape of the front handle hole is cylindrical, and its diameter is 1 / 4-1 / 3 of the diameter of the front handle;

[0032] The front handle hole extends from the end surface to the small diameter section of the front handle and passes through the handle body of the front handle;

[0033] Furthermore, the axis of the front handle hole is parallel to the axis of the front handle.

[0034] Optionally, the front end hole of the blade body is located at the center of the front end surface of the blade body, directly opposite to the front handle hole, and the diameter of the front end hole of the blade body matches the small diameter section of the front handle to ensure that the front handle can be smoothly inserted; the depth of the front end hole of the blade body is generally less than 1 / 3 of the length of the blade body, and the axis of the front end hole of the blade body coincides with the axis of the blade body.

[0035] Compared with the prior art, the utility model has the following advantages:

[0036] The utility model proposes an improved combined broach design, that is, through holes are opened on the front and rear handles to connect the inner cavity of the broach body with the outside to form a flow channel. This design cleverly solves the problems of difficult assembly and poor heat dissipation, and has significant practical value.

Brief Description of the Drawings

[0037] Figure 1 is a schematic diagram of a modular broach in one embodiment;

[0038] Figure 2 is a schematic diagram of a modular broach in another embodiment;

[0039] Figure 3 is a schematic diagram of a modular broach in another embodiment;

[0040] Figure 4 is a schematic diagram of a modular broach in another embodiment;

[0041] Figure 5 yes Figure 4 A partial enlarged view of the front handle in the figure;

[0042] Figure 6 yes Figure 4 A partial enlarged view of the posterior handle.

[0043] Figure numerals: 1. knife body, 2. front handle, 3. rear handle, 4. front handle hole, 5. rear handle hole, 6. front end hole of knife body, 7. rear end hole of knife body. [Specific implementation method]

[0044] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and is not to be construed as being limited to the embodiments described herein, but rather these embodiments are provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0045] It should be understood that the various steps described in the method implementation of the present utility model can be performed in different orders and / or performed in parallel. In addition, the method implementation may include additional steps and / or omit the steps shown. The scope of the present utility model is not limited in this respect.

[0046] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to". The term "connected" may be directly connected or indirectly connected through intermediate components (elements). The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0047] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish between devices, modules or units, and are not used to limit these devices, modules or units to be different devices, modules or units, nor are they used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0048] In one embodiment, Figure 1As shown, the utility model provides a combined broach, comprising:

[0049] The broach body (or blade body) 1, the front handle 2 and the rear handle 3, wherein:

[0050] The broach body is a cylindrical structure, and the front handle and the rear handle are respectively fixedly connected to the broach body.

[0051] In the prior art, the broach body (or tool body) 1, the front handle 2 and the rear handle 3 do not have a threaded structure. Correspondingly, in the present invention, a through inner hole is provided inside the broach body, and a plurality of threaded holes are processed on the two end faces of the broach body, and the plurality of threaded holes are distributed in a circumferential array;

[0052] One end of the front handle and / or the rear handle is a cylindrical structure, the size of which matches the inner hole of the broach body, and the other end is a cylindrical structure, and a through hole corresponding to the threaded hole of the broach body is processed on the end surface;

[0053] The combined broach further comprises screws, which sequentially pass through the through holes of the front handle and / or the rear handle and the corresponding threaded holes on the broach body, so that the front handle and the rear handle are fixedly connected to the broach body.

[0054] like Figure 1 The broach body (i.e., the tool body) is a hollow cylindrical structure with an inner hole running through it. This inner hole is used as a processing reference. On the two end faces of the broach body, multiple threaded holes are processed. These threaded holes are distributed in a circular array. One end of the front and rear handles (i.e., the front handle and the rear handle) is a smooth cylinder, the size of which matches the inner hole of the broach body. The other end of the front and rear handles is a larger cylinder, and a through hole corresponding to the threaded hole of the broach body is processed on its end face. In addition, the broach as a whole is connected to the broach body by screws through the front and rear handles and the corresponding threaded holes on the broach body in turn, and then tightened.

[0055] The connection process of this structure is as follows:

[0056] 1. Insert the smooth ends of the front and rear handles into the inner holes at both ends of the broach body.

[0057] 2. Rotate the front and rear handles to align the through holes on their end faces with the threaded holes on the end faces of the broach body.

[0058] 3. Pass the screws through the through holes of the front and rear handles in sequence and screw them into the threaded holes of the broach body until they are tightened.

[0059] 4. The front and rear handles thus form a stable whole with the broach body.

[0060] This inner hole is used as a reference, a threaded hole is opened on the end face, and the front and rear handle end face through holes are connected with screws, which can better realize the positioning and fastening of the front and rear handles and the broach body.

[0061] Alternatively, if Figure 2 As shown, in this embodiment, a through hole may be provided on the front handle and the rear handle respectively, which are defined as the front handle hole and the rear handle hole respectively, wherein the front handle hole and the rear handle hole are connected to the hollow inner cavity of the broach body.

[0062] The positions of the front handle hole and the rear handle hole should meet the following requirements:

[0063] a. After installation on the cutter body, the front handle hole and the rear handle hole should be connected to the hollow inner cavity of the cutter body.

[0064] b. The axis of the front handle hole and the rear handle hole should be as close to the axis of the handle body as possible to reduce the impact on the strength of the handle body.

[0065] In addition, the size requirements for the front handle hole and the rear handle hole are:

[0066] a. The hole diameter should be large enough to achieve good ventilation, but not too large to affect the strength of the handle.

[0067] b. The depth of the hole should be reasonably designed according to the length of the handle. The hole depth is usually not less than the length of the handle installed in the cutter body.

[0068] The processing methods of the front handle hole and the rear handle hole include:

[0069] a. Before the front and rear handles are installed on the cutter body, the through holes should be pre-processed, and drilling, reaming and other processes can be used.

[0070] b. The inner wall of the through hole should be smooth to reduce the resistance of gas flow. The hole wall can be surface treated if necessary.

[0071] The through hole designed in this way can play the role of exhaust when installing the front and rear handles:

[0072] When the handle is pressed into the hollow inner cavity of the knife body, the air in the inner cavity can be quickly discharged through the through hole, reducing the resistance caused by air compression, facilitating the smooth installation of the handle and saving installation time.

[0073] During the subsequent processing of the cutter body, the through hole can play a role in heat dissipation:

[0074] When the cutter body is grinding, the temperature of the cutting area will rise rapidly. The through hole connects the inside and outside of the cutter body, and the processing heat can be discharged from the inner cavity to the outside through convection, which slows down the thermal deformation of the cutter body and helps to ensure the processing accuracy.

[0075] It can be seen that the assembly performance and use performance of the combined broach can be significantly improved by reasonably designing and processing through holes on the handle and utilizing the ventilation and heat dissipation effects of the holes.

[0076] Alternatively, if Figure 3 As shown, the front handle hole 4 and the rear handle hole 5 can be replaced by a front handle flat 4 and a rear handle flat 5. Specifically, one end of the front handle and the rear handle is a threaded portion, and a flat surface is processed on the extension of the threaded portion, which are respectively defined as the front handle flat and the rear handle flat.

[0077] Optionally, the front handle flat and the rear handle flat are flat cylinders, or polygonal cylinders.

[0078] Specifically, the geometric shapes of the front handle flat and the rear handle flat can be:

[0079] a. It can be two parallel planes, forming a flat cylinder.

[0080] b. It can also be a square or hexagonal cylinder, which is equivalent to cutting a square column or hexagonal prism out of a cylinder.

[0081] c. It can also be a plurality of evenly distributed pits on the cylindrical surface to facilitate the engagement of the wrench.

[0082] In addition, the size requirements for the front handle flat and the rear handle flat are:

[0083] a. The width of the flat surface should match the opening size of commonly used wrenches. Generally, specifications such as 4mm, 5mm, and 6mm can be selected.

[0084] b. The length of the flat face should be sufficient to allow the wrench to apply force and should usually be greater than the length of the teeth of the wrench.

[0085] c. The height of the flat surface (or the depth of the pit) should not be too large to avoid weakening the strength of the handle, but it should be sufficient to prevent the wrench from slipping.

[0086] The position requirements of the front handle flat and the back handle flat are as follows:

[0087] a. Usually designed near the rear end of the handle, that is, near the end connected to the blade body.

[0088] b. Avoid other structures on the handle, such as threads, through holes, etc.

[0089] c. Multiple sets of flat surfaces can be designed and distributed at different positions around the handle to facilitate applying force from different angles.

[0090] In addition, the processing methods for the front handle flat and the rear handle flat are usually:

[0091] a. When turning the handle, the flat surface can be processed synchronously by CNC or special machine equipment.

[0092] b. You can also first process the cylinder, and then use milling, grinding and other processes to process the flat surface.

[0093] The flat surface designed in this way can cooperate well with the wrench when used:

[0094] When the wrench is stuck on the flat surface, a large torque can be applied with the help of the lever principle, and only a small force is needed to tighten or remove the handle. However, it is difficult for the smooth cylindrical surface to get stuck on the wrench, and it is easy to slip when applying force, which makes loading and unloading inefficient and laborious.

[0095] In addition, a force rod can be put on the wrench rod to further extend the force arm, so as to achieve twice the result with half the effort.

[0096] In another embodiment, if Figure 4 As shown, the utility model also provides a combined broach, comprising:

[0097] The knife body, the front handle, the rear handle, the front handle hole, the rear handle hole, the front end hole of the knife body and the rear end hole of the knife body, wherein:

[0098] The blade body is in the shape of a hollow cylinder, the front end hole and the rear end hole of the blade body are respectively arranged on the front end face and the rear end face of the blade body, and the front end hole and the rear end hole of the blade body are through holes, connecting the hollow inner cavity of the blade body;

[0099] The front handle and the rear handle are cylinders with different diameters at both ends, the end with a smaller diameter is used to be inserted into the inner cavity of the tool body, and the end with a larger diameter is exposed outside the tool body and is used to connect to a machine tool or tooling;

[0100] The front handle hole and the rear handle hole are respectively arranged at the ends of the front handle and the rear handle with larger diameters, and the front handle hole and the rear handle hole are through holes that penetrate the handle body, one end of which is connected to the outside world and the other end of which is connected to the smaller diameter multi-end surface of the handle body.

[0101] The smaller diameter end of the front handle is inserted into the front end hole of the knife body, and the smaller diameter end of the rear handle is inserted into the rear end hole of the knife body, and they meet in the middle of the inner cavity of the knife body.

[0102] In addition, the front handle hole is arranged at an end of the front handle with a larger diameter and is located at the center of the end surface;

[0103] The shape of the front handle hole is cylindrical, and its diameter is 1 / 7-1 / 5 of the diameter of the front handle;

[0104] The front handle hole extends from the end surface to the small diameter section of the front handle and passes through the handle body of the front handle;

[0105] Furthermore, the axis of the front handle hole is parallel to the axis of the front handle.

[0106] In addition, the front end hole of the blade body is located at the center of the front end surface of the blade body, directly opposite to the front handle hole, and the diameter of the front end hole of the blade body matches the small diameter section of the front handle to ensure that the front handle can be smoothly inserted; the depth of the front end hole of the blade body is generally less than 1 / 3 of the length of the blade body, and the axis of the front end hole of the blade body coincides with the axis of the blade body.

[0107] Each component will be described in detail below:

[0108] 1. Overall structure:

[0109] As can be seen from the markings in the figure, the broach is composed of three main parts: a broach body (1), a front handle (2), and a rear handle (3). The three parts are assembled together to form a complete broach.

[0110] 2. Blade body (1):

[0111] The tool body is the core component of the broach and is in the shape of a hollow cylinder.

[0112] There is a hole on the front and rear end surfaces of the cutter body, respectively referred to as the front end hole (6) of the cutter body and the rear end hole (7) of the cutter body.

[0113] The front end hole and the rear end hole of the knife body are through holes, which are connected to the hollow inner cavity of the knife body.

[0114] The hollow inner cavity of the knife body is used to accommodate the front handle and the rear handle to be inserted.

[0115] 3. Front handle (2) and rear handle (3):

[0116] The front handle and the rear handle are cylinders with unequal diameters at both ends.

[0117] The end with a smaller diameter is used to insert into the inner cavity of the cutter body, and the fit is more tight.

[0118] The end with a larger diameter is exposed outside the tool body and is used to connect to a machine tool or tooling.

[0119] 4. Front handle hole (4) and rear handle hole (5):

[0120] The special design of the front and rear handles is that a front handle hole and a rear handle hole are respectively processed on the large diameter end thereof.

[0121] The front handle hole and the rear handle hole are through holes penetrating the handle body, one end of which is communicated with the outside world, and the other end of which is communicated with the small-diameter end face of the handle body.

[0122] When the front and rear handles are assembled on the cutter body, the front handle hole and the rear handle hole will be connected with the inner cavity of the cutter body.

[0123] 5. Overall assembly:

[0124] During assembly, the small diameter end of the front handle is inserted into the front end hole of the cutter body, and the small diameter end of the rear handle is inserted into the rear end hole of the cutter body.

[0125] The front and rear handles are respectively inserted from two ends of the knife body and meet in the middle of the inner cavity of the knife body.

[0126] The front handle hole opens toward the front end of the knife body, and the rear handle hole opens toward the rear end of the knife body.

[0127] The front and rear handles are closely matched with the knife body, and at the same time, the front handle hole, the rear handle hole, the inner cavity of the knife body, and the holes at both ends of the knife body form a mutually penetrating channel.

[0128] The characteristics of this structural design are:

[0129] 1. When the front and rear handles are installed into the cutter body, the air in the inner cavity of the cutter body can be quickly discharged from the front handle hole and the rear handle hole, which is conducive to the smooth insertion of the handle body.

[0130] 2. When using a broach, the heat generated in the cutting area of ​​the tool body can be discharged through the channels formed by the front and rear end holes of the tool body, the inner cavity of the tool body, and the front and rear shank holes, which helps to reduce the temperature of the tool body and reduce thermal deformation.

[0131] This embodiment cleverly utilizes a simple through-hole structure to improve the assembly performance and heat dissipation performance of the broach.

[0132] Furthermore,

[0133] For the front handle hole (4):

[0134] a. The front handle hole is machined at the large diameter end of the front handle, usually located in the center of the end face.

[0135] b. The shape of the hole is cylindrical, and the diameter is determined according to the cutter body model and exhaust requirements, generally 1 / 4 to 1 / 3 of the front handle diameter.

[0136] c. The front handle hole extends from the end face to the small diameter section of the front handle, penetrating the entire handle body.

[0137] d. The inner wall of the hole is smooth without burrs or edges to reduce air flow resistance.

[0138] e. The axis of the front handle hole is parallel to the axis of the front handle to ensure smooth flow channel.

[0139] For the rear handle hole (5):

[0140] a. The position, shape and size of the rear handle hole are basically the same as those of the front handle hole, and it is also processed on the large diameter end face of the rear handle.

[0141] b. The rear handle hole is also a through hole, extending from the end face to the small diameter section of the rear handle.

[0142] c. The inner wall quality requirements of the hole are the same as those of the front handle hole to ensure good flow performance.

[0143] d. The axis of the rear handle hole is also parallel to the axis of the rear handle, maintaining the symmetry of the entire channel.

[0144] For the front hole (6) of the cutter body:

[0145] a. The front end hole of the cutter body is located at the center of the front end surface of the cutter body, directly opposite to the front handle hole.

[0146] b. The diameter of the front end hole matches the small diameter section of the front handle to ensure that the front handle can be inserted smoothly.

[0147] c. The depth of the front hole generally does not exceed 1 / 3 of the length of the blade to ensure the strength and rigidity of the blade.

[0148] d. The inner wall of the front end hole must be smooth, and the mating surface with the front handle must have high precision to ensure good assembly performance.

[0149] e. The axis of the front end hole coincides with the axis of the cutter body, ensuring the coaxiality of the front handle installation.

[0150] For the rear hole (7) of the cutter body:

[0151] a. The position and size of the rear end hole of the cutter body are similar to those of the front end hole and are located in the center of the rear end face of the cutter body.

[0152] b. The diameter of the rear end hole matches the small diameter section of the rear handle to ensure smooth installation of the rear handle.

[0153] c. The depth of the rear end hole is also controlled within 1 / 3 of the length of the cutter body to ensure the strength of the cutter body.

[0154] d. The quality requirements of the inner wall of the rear end hole must be consistent with that of the front end hole to ensure a good fit with the rear handle.

[0155] e. The axis of the rear end hole also coincides with the axis of the cutter body, ensuring the rotation accuracy of the entire cutter.

[0156] It should be noted that the front and rear holes of the knife body are not through-holes. They extend from both ends of the knife body to the middle of the inner cavity and merge at the center of the knife body. This can ensure the overall strength of the knife body and provide sufficient installation depth for the front and rear handles.

[0157] The front and rear end holes and the front and rear handle holes together form a flow channel connecting the inside and outside of the tool body. This channel allows the air in the inner cavity to be discharged smoothly when the tool is assembled, reducing the assembly resistance; when the tool is used, it can quickly export the cutting heat, improving the heat dissipation performance of the tool.

[0158] The following is a detailed description with a specific example:

[0159] In the combined broach structure, through holes are punched on the front and rear handles, so that the air in the tool body can flow when the handle is installed, without forming pressure, and it is easy to tighten. When processing the tool body, the grinding heat can be discharged through the vent holes, reducing heat accumulation and ensuring processing accuracy.

[0160] Position of through holes:

[0161] a. The through hole should be machined at the large diameter end of the front and rear shanks, that is, the end exposed outside the cutter body.

[0162] b. One end of the through hole should be opened on the end surface of the handle body, and the other end should pass through to the small diameter section of the handle body.

[0163] c. The position of the through hole should be as close to the center of the handle as possible to reduce the impact on the strength and rigidity of the handle.

[0164] Through hole size:

[0165] a. The diameter of the through hole should be reasonably designed according to the inner volume of the cutter body and the expected exhaust speed.

[0166] b. A diameter that is too small will affect the exhaust and heat dissipation effects, while a diameter that is too large will weaken the strength of the handle.

[0167] c. Usually the diameter range is 10-16mm, and the specific size needs to be determined according to the cutter body model.

[0168] Number of through holes:

[0169] a. Multiple through holes can be processed on one handle while ensuring strength.

[0170] b. Multiple through holes are distributed on the circumference of the handle body to speed up exhaust and heat dissipation.

[0171] c. The number of through holes should not be too many to avoid weakening the strength of the handle. 2-4 is appropriate.

[0172] Through hole processing:

[0173] a. The through hole can be formed in one step when turning the handle body, or the handle body can be machined first and then the hole can be drilled.

[0174] b. Appropriate drill bits and cutting parameters should be selected to ensure smooth hole walls and reduce flow resistance.

[0175] c. After through hole processing, deburring, chamfering and other treatments can be performed to improve assembly performance.

[0176] Working mechanism of through hole:

[0177] a. During installation, the through hole on the end face of the handle allows the air in the inner cavity of the cutter body to quickly flow into the handle body and then be discharged from the small diameter end of the handle body, forming a smooth flow channel to balance the internal and external pressures.

[0178] b. During use, when the temperature of the cutting area of ​​the cutter body rises, the heat will flow to the inside of the handle body through the air convection in the inner cavity of the cutter body, and then be discharged to the outside through the through holes of the handle body, thus playing an effective heat dissipation role.

[0179] c. The existence of the through hole reduces the degree of occlusion of the inner cavity of the tool body, which is conducive to heat flow, reduces the temperature gradient of the tool body, and reduces thermal deformation, thereby ensuring the processing accuracy of the tool.

[0180] In addition, the optimal design of through holes can include:

[0181] a. Some auxiliary structures, such as spiral grooves, vortex sheets, etc., can be designed inside the through hole to enhance the exhaust and heat dissipation effects.

[0182] b. A groove or boss structure can be designed on the end face of the handle to guide the air flow to the through hole and improve the exhaust efficiency.

[0183] c. You can also design structures such as retaining ring grooves and O-ring grooves at the outer end of the through hole, and install seals or filters to prevent foreign matter such as chips and dust from entering the inner cavity of the cutter body.

[0184] Figure 5 This is a partial enlarged view of the front handle ( Figure 4 The mark A) in Figure 5 As shown, Figure 5 The large diameter end of the front handle (2), that is, the end exposed outside the cutter body, is shown in the figure. On the end face of the large diameter end of the front handle, a clear through hole, namely the front handle hole (4), can be seen. The front handle hole is circular and located at the center of the end face. This design is conducive to ensuring the strength and symmetry of the handle body. The diameter of the front handle hole is moderate, generally between 1 / 7 and 1 / 5 of the handle body diameter. The specific size of the hole diameter needs to be determined according to the cutter body model and exhaust requirements. The inner wall of the front handle hole is smooth without obvious burrs or edges. This shows that the processing quality of the hole is high, which is conducive to reducing air flow resistance. The front handle hole extends from the end face to the small diameter section of the front handle. This means that the front handle hole runs through the entire handle body, forming a channel connected to the inner cavity of the cutter body.

[0185] Figure 6 This is a partial enlarged view of the rear handle ( Figure 4 The mark B) in Figure 5 akin, Figure 6The large diameter end of the rear handle (3), that is, the end exposed outside the blade body, is clearly shown in the figure. Similar to the front handle, a through hole is also processed on the end face of the large diameter end of the rear handle, namely the rear handle hole (5). The position, shape and size of the rear handle hole are basically the same as those of the front handle hole, which reflects the symmetry and balance of the entire design. The inner wall of the rear handle hole is also relatively smooth and has a high surface quality. This helps to reduce the resistance to air flow and improve the exhaust and heat dissipation efficiency. The rear handle hole is also a through hole, extending from the end face to the small diameter section of the rear handle. In this way, the rear handle hole is also connected to the inner cavity of the blade body, forming another flow channel. From Figure 6 It can also be seen that the length of the large diameter section of the rear handle is slightly longer than that of the front handle. This is designed for balance or connection needs.

[0186] Compared with the prior art, the utility model has the following advantages:

[0187] The utility model proposes an improved combined broach design, that is, through holes are opened on the front and rear handles to connect the inner cavity of the broach body with the outside to form a flow channel. This design cleverly solves the problems of difficult assembly and poor heat dissipation, and has significant practical value.

[0188] Some exemplary embodiments of the utility model are described above, but those skilled in the art will appreciate that changes may be made to these exemplary embodiments without departing from the principles or spirit of the utility model, and the scope of the utility model is defined by the claims and their equivalents.

Claims

1. A combined broach, characterized in that: include: The broach body, the front handle and the rear handle, wherein: The broach body is a cylindrical structure, and the front handle and the rear handle are respectively fixedly connected to the broach body; The broach body is provided with a through inner hole, and two end faces of the broach body are processed with a plurality of threaded holes, and the plurality of threaded holes are distributed in a circumferential array; One end of the front handle and / or the rear handle is a cylindrical structure, the size of which matches the inner hole of the broach body, and the other end is a cylindrical structure, and a through hole corresponding to the threaded hole of the broach body is processed on the end surface; The combined broach further comprises a screw, which passes through the through hole of the front handle and / or the rear handle and the corresponding threaded hole on the broach body in sequence, so that the front handle and the rear handle are fixedly connected to the broach body; The front handle and the rear handle are respectively provided with a through hole, which are defined as a front handle hole and a rear handle hole, respectively, wherein the front handle hole and the rear handle hole are communicated with the hollow inner cavity of the broach body.

2. The combined broach according to claim 1, characterized in that: One end of the front handle and the rear handle is a threaded portion, and a flat surface is processed on the extension of the threaded portion, which is defined as the front handle flat and the rear handle flat respectively.

3. The combined broach according to claim 2, characterized in that: The front flat handle and the rear flat handle are flat cylinders or polygonal cylinders.

4. A combined broach, characterized in that: include: The knife body, the front handle, the rear handle, the front handle hole, the rear handle hole, the front end hole of the knife body and the rear end hole of the knife body, wherein: The blade body is in the shape of a hollow cylinder, the front end hole and the rear end hole of the blade body are respectively arranged on the front end face and the rear end face of the blade body, and the front end hole and the rear end hole of the blade body are through holes, connecting the hollow inner cavity of the blade body; The front handle and the rear handle are cylinders with different diameters at both ends, the end with a smaller diameter is used to be inserted into the inner cavity of the tool body, and the end with a larger diameter is exposed outside the tool body and is used to connect to a machine tool or tooling; The front handle hole and the rear handle hole are respectively arranged at the ends of the front handle and the rear handle with larger diameters, and the front handle hole and the rear handle hole are through holes that penetrate the handle body, one end of which is connected to the outside world and the other end of which is connected to the smaller diameter multi-end surface of the handle body.

5. The combined broach according to claim 4, characterized in that: The smaller diameter end of the front handle is inserted into the front end hole of the knife body, and the smaller diameter end of the rear handle is inserted into the rear end hole of the knife body, and they meet in the middle of the inner cavity of the knife body.

6. The combined broach according to claim 4, characterized in that: The front handle hole is arranged at an end of the front handle with a larger diameter and is located at the center of the end surface; The shape of the front handle hole is cylindrical, and its diameter is 1 / 4-1 / 3 of the diameter of the front handle; The front handle hole extends from the end surface to the small diameter section of the front handle and passes through the handle body of the front handle; Furthermore, the axis of the front handle hole is parallel to the axis of the front handle.

7. The combined broach according to claim 4, characterized in that: The front end hole of the knife body is located at the center of the front end surface of the knife body, facing the front handle hole, and the diameter of the front end hole of the knife body matches the small diameter section of the front handle to ensure that the front handle can be smoothly inserted; the depth of the front end hole of the knife body is generally less than 1 / 3 of the length of the knife body, and the axis of the front end hole of the knife body coincides with the axis of the knife body.

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