Collet with improved cooling effect

Abstract

Collet with improved cooling effect, comprising: - a collet main body (10) having a center line (C), a front end (11) and a rear end (12) and including a through hole (13) extending along the center line (C); - a plurality of slots extending from the outer periphery of the collet main body (10) through the collet main body (10) and opening into the through hole (13) and comprising a plurality of front slots (21) and a plurality of rear slots (22), wherein the front slots (21) extend from the front end (11) of the collet main body (10) towards the rear end (12) thereof and the rear slots (22) extend from the rear end (12) of the collet main body (10) towards the front end (11) thereof; - at least one inner coolant groove (30, 30A) which is recessed on the inner surface of the through hole (13) and extends from the front end (11) of the collet main body (10) toward the rear end (12) thereof so as to communicate with the rear slots (22); and - at least one outer coolant bore (40, 40A) which is arranged at a distance from the through hole (13) and extends from the front end (11) of the collet main body (10) towards the rear end (12) thereof so as to communicate with the rear slots (22), the outer coolant bore (40, 40A) being directed towards the front end (11) of the collet main body (10) and successively inclining towards the centre line (C) of the collet main body (10).

Description

[0001] The utility model relates to a collet, in particular a collet with an improved cooling effect.

[0002] A collet is a component used to secure a tool or other machining tools to the spindle. To ensure tool cooling, some collets are designed with a coolant channel inside, allowing coolant to flow through and cool the tool attached to the collet. This lowers the cutting temperature and slows tool wear.

[0003] However, conventional collets only have a single coolant channel. For example, the coolant can directly contact and cool the tool in the collet, or the coolant can be sprayed from the collet toward the workpiece to reduce the temperature of the workpiece at the machining position. In this case, the tool is not cooled sufficiently, and the cooling effect therefore needs to be improved.

[0004] The utility model is based on the object of providing a collet with an improved cooling effect, which is equipped with coolant flow channels of various types so that the coolant can cool the tool at different points in order to improve the cooling effect.

[0005] The object is achieved by a collet with an improved cooling effect having the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0006] The collet with improved cooling effect according to the utility model comprises: - a collet main body having a center line and including a through hole extending along the center line; - a plurality of slots extending from the outer periphery of the collet main body through the collet main body and opening into the through hole 13, and comprising a plurality of front slots and a plurality of rear slots, the front slots extending from the front end of the collet main body toward the rear end thereof, and the rear slots extending from the rear end of the collet main body toward the front end thereof; - at least one inner coolant groove recessed on the inner surface of the through hole and extending from the front end of the collet main body toward the rear end thereof so as to communicate with the rear slots; and - at least one outer coolant hole arranged at a distance from the through hole and extending from the front end of the collet main body toward the rear end thereof so as to communicate with the rear slots, the outer coolant hole being directed toward the front end of the collet main body and successively inclined toward the center line of the collet main body.

[0007] The collet with improved cooling effect according to the utility model is characterized by the following: The at least one inner coolant channel and the at least one outer coolant bore form different cooling paths, via which the tool can be cooled, respectively, inside the collet and at the point where the tool is in contact with the workpiece. Thus, the collet ensures increased cooling of the tool compared to conventional collets with a single coolant channel. This contributes to reducing tool wear caused by thermomechanical fatigue, extending the tool's service life, and reducing tool acquisition costs and manufacturing costs for tool manufacturers.

[0008] The utility model is described in detail below using exemplary embodiments and with reference to the drawings. The drawings show: Fig. 1 is a perspective view of a first preferred embodiment of a collet chuck with improved cooling effect according to the utility model, Fig. 2 a front view of the collet according to the utility model in Fig. 1, Fig. 3 a sectional view along the section line AA in Fig. 2, Fig. 4 a perspective view of the structure of a spindle of the collet according to the utility model in Fig. 1, Fig. 5 a side and sectional view of the structure of a spindle of the collet according to the utility model in Fig. 1, Fig. 6 is a perspective view of a second preferred embodiment of a collet chuck with improved cooling effect according to the utility model, Fig. 7 a front view of the collet according to the utility model in Fig. 6, and Fig. 8 a sectional view along the section line BB in Fig. 7.

[0009] The objects, features, and advantages of the present utility model are explained in more detail below with reference to the detailed description of exemplary embodiments and the accompanying drawings. The utility model is not intended to be limited to the features apparent from the description and the drawings.

[0010] In Fig. 1 shows a first preferred embodiment of a collet 80 with improved cooling effect according to the utility model, which comprises a collet main body 10, a plurality of slots, a plurality of internal coolant grooves 30 and a plurality of coolant holes 40, wherein the slots, the internal coolant grooves 30 and the coolant holes 40 are formed on the collet main body 10.

[0011] As in Fig. 1 to Fig. 3, the collet main body 10 has a center line C, a front end 11, and a rear end 12, wherein the front end 11 and the rear end 12 are arranged opposite each other on the center line C. A tool is inserted from the front end 11 of the collet main body 10 into the collet main body 10 and thus connected to the collet main body 10. The rear end 12 of the collet main body 10 is connected to a tool holder main body so that the collet main body 10 can be mounted on a spindle. The collet main body 10 further has a through hole 13 extending along the center line C to the front end 11 and the rear end 12, wherein a tool can be received in the through hole 13 and thus connected to the collet main body 10.

[0012] As in Fig. 1 to Fig. 3, the slots are spaced apart such that they extend from the outer periphery of the collet main body 10 through the collet main body 10 and open into the through hole 13. The slots include a plurality of front slots 21 and a plurality of rear slots 22, wherein the front slots 21 extend from the front end 11 of the collet main body 10 toward the rear end 12 thereof, and the rear slots 22 extend from the rear end 12 of the collet main body 10 toward the front end 11 thereof.

[0013] In particular, the collet 80 is a conventional elastic collet. The front and rear slots 21, 22, which extend from the outer periphery of the collet main body 10 through the collet main body 10 and open into the through hole 13, ensure that the collet main body 10 deforms when a tool is mounted in and removed from the through hole 13 of the collet main body 10. Once the tool is mounted in the through hole 13, the collet main body 10 is tightened with a lock nut so that the collet main body 10 deforms, thus clamping the tool. This locks the tool and prevents it from coming loose.

[0014] Two circular conical structures are formed at a distance from one another on the collet main body 10, one of which tapers toward the front end 11 of the collet main body 10, the collet main body 10 being deformed by the interaction of said circular conical structure with the front slots 21. The other circular conical structure tapers toward the rear end 12 of the collet main body 10, the collet main body 10 being deformed by the interaction of said circular conical structure with the rear slots 22. A circular conical profiled recess is formed on the inside of the lock nut and the inside of the tool holder main body, the two circular conical structures being positively fixed by the circular conical profiled recesses, so that the collet main body 10 clamps the tool.

[0015] As in Fig. 1 to Fig. As shown in Figure 3, the internal coolant grooves 30 are arranged around the through hole 13. The internal coolant grooves 30 are recessed on the inner surface of the collet main body 10 and extend from the front end 11 of the collet main body 10 toward the rear end 12 thereof, communicating with the rear slots 22, thereby forming a path for coolant to flow. Here, the internal coolant grooves 30 connected to the rear slots 22 are spaced apart from the front slots 21.

[0016] As in Fig. 1 to Fig. 3, the outer coolant holes 40 are also arranged around the through-hole 13. The outer coolant holes 40 are arranged at a distance from the through-hole 13 and the inner coolant grooves 30 and extend continuously from the front end 11 of the collet main body 10 toward the rear end 12 thereof, communicating with the rear slots 22. Furthermore, the outer coolant holes 40 are directed toward the front end 11 of the collet main body 10 and gradually incline toward the centerline C of the collet main body 10, thereby creating another path for the coolant to flow. Here, the outer coolant holes 40 connected to the rear slots 22 are also spaced from the front slots 21.

[0017] For the use of the collet 80 with improved cooling effect on a spindle 91, Fig. 4. The collet 80 is firmly connected to a tool holder main body 92 by means of a lock nut. A tool 94 is inserted into the through hole 13 of the collet 80 and secured therein. The tool holder main body 92 is then attached to the spindle 91. By rotating the spindle 91, the tool 94 is rotated to perform machining of a workpiece.

[0018] As in Fig. As shown in Figure 5, a coolant passage 95 is axially continuous on the tool holder main body 92 in correspondence with the collet chuck 80. During machining, the coolant flows through the passage inside the spindle 91 into the coolant passage 95 of the tool holder main body 92 and enters the extending rear slots 22 at the rear end 12 of the collet main body 10. Further, the coolant flows into the inner coolant grooves 30 and the outer coolant holes 40, respectively, to achieve different cooling effects.

[0019] By allowing the coolant to flow through the rear slots 22 into the internal coolant grooves 30 recessed on the upper surface of the through hole 13, the time during which the coolant inside the collet 80 is in direct contact with the tool 94 can be extended. Thus, the part of the tool 94 located inside the collet 80 and the collet main body 10 can be cooled with the coolant. After flowing through the internal coolant grooves 30, the coolant is sprayed onto the workpiece from the front end 11 of the collet main body 10.

[0020] After the coolant flows through the rear slots 22 into the outer coolant holes 40, which are spaced apart from the through hole 13 and the inner coolant grooves 30, the coolant flows in the path where it is not in contact with the tool 94. After the coolant flows through the outer coolant holes 40, it is sprayed out of the front end 11 of the collet main body 10. By structurally designing the outer coolant holes 40 toward the front end 11 of the collet main body 10 and inclining toward the center line C of the collet main body 10, the coolant can be sprayed from the outer coolant holes 40 onto the part of the tool 94 where the tool 94 is in contact with the workpiece, thereby directly cooling the machining area heated due to friction.

[0021] According to the utility model, the inner coolant channels 30 and the outer coolant bores 40 form different cooling paths, via which the tool can be cooled respectively inside the collet 80 and at the machining point where the tool 94 is in contact with the workpiece, so that the collet 80 according to the utility model ensures increased cooling of the tool 94 compared to conventional collets with a single coolant channel, which contributes to reducing the wear of the tool 94 caused by thermomechanical fatigue, extending the service life of the tool 94 and reducing the purchase costs for tools 94 and the manufacturing costs for tool manufacturers.

[0022] In the first preferred embodiment, the collet 80 includes a plurality of inner coolant grooves 30 and a plurality of outer coolant bores 40, specifically, three inner coolant grooves 30 and three outer coolant bores 40. In further embodiments, different coolant paths can also be formed in a collet with a single inner coolant groove 30 and a single outer coolant bore 40, thereby enhancing the cooling effect. For an optimal cooling effect, the number of inner coolant grooves 30 and outer coolant bores 40 can be determined according to the length and outer diameter of the collet main body 10, the number of rear slots 22, and the hole diameter of the through hole.

[0023] As in Fig. 2, the inner coolant grooves 30 are further arranged at an equal angle to each other around the through hole 13. This ensures that the tool 94 and the collet main body 10 inside the collet 80 are evenly cooled. The outer coolant holes 40 are also arranged at an equal angle to each other around the through hole 13. When the coolant is sprayed from the front end 11 of the collet main body 10, the coolant can be sprayed from different angles onto the tool 94 and the machining point where the tool 94 is in contact with the workpiece, thereby achieving a better cooling effect.

[0024] As in Fig. 2, in the first embodiment, the shortest distance between the inner surface of the outer coolant bore 40 and the inner surface of the through hole 13 is defined as distance G. The through hole 13 has a hole diameter D. As shown in Fig. As shown in Figure 3, an included angle θ exists between the outer coolant hole 40 inclined toward the center line C of the collet main body 10 and the center line C of the collet main body 10, with the tangent value of the included angle θ being one-quarter of the value obtained by dividing the distance G by the hole diameter D. The formula for this is as follows: tanθ=G4D

[0025] As in Fig. 5, the length E of the portion of the tool 94 protruding from the front end 11 of the collet main body 10 is approximately four times the diameter of the tool 94, that is, four times the hole diameter D of the through hole 13 when the tool 94 is mounted in the through hole 13 of the collet 80. This length E is advantageously determined so that the tool 94 does not wobble because the portion of the tool 94 protruding from the collet main body 10 is not too long. At the same time, the length E is not too short, so that the workpiece does not collide with the lock nut 93 or other components on the spindle during machining.

[0026] In a first preferred embodiment, the included angle θ is determined such that the tangent value of the included angle θ is one-quarter of the value obtained by dividing the distance G by the hole diameter D. After the coolant is jetted out of the front end 11 of the collet main body 10 through the external coolant holes, the coolant can be precisely jetted onto the machining location where the tip of the tool 94 is in contact with the workpiece, thus achieving an optimal cooling effect.

[0027] In Fig. 6 to Fig. Figure 8 shows a preferred embodiment of a collet chuck 80A with improved cooling effect according to the utility model. The second preferred embodiment differs from the first preferred embodiment in that in the first preferred embodiment Fig. 2 the inner coolant channels 30 and the outer coolant holes 40 are arranged offset from one another around the through hole 13 and in the second preferred embodiment from Fig. 8 the respective inner coolant groove 30A and the corresponding outer coolant bore 40A are connected to each other by means of the corresponding rear slot 22.

[0028] As in Fig. As shown in Figure 2, in the first preferred embodiment, the inner coolant grooves 30 and the outer coolant bores 40 are arranged offset from each other around the through-hole 13. This means that the inner coolant grooves 30 and the outer coolant bores 40 are located in different radial directions of the through-hole 13. Because the inner coolant grooves 30 and the outer coolant bores 40 are formed at positions in different radial directions, this prevents the structural strength of the through-hole 13 from being reduced in its radial directions during manufacturing.

[0029] As in Fig.As shown in Figure 7, in the second preferred embodiment, the respective inner coolant groove 30A and the corresponding outer coolant bore 40A are connected to each other by means of the corresponding rear slot 22. That is, the respective inner coolant groove 30A and the corresponding outer coolant bore 40A are located in the same radial direction. Thus, the respective coolant bore 40A and the through hole 13 are separated from the corresponding coolant groove 30A. This structural configuration ensures that the heat of the tool 94 transferred through the collet main body 10 to the coolant bores 40A is reduced. Under the action of the coolant sprayed from the coolant bores 40A onto the machining site, the temperature is kept low, thereby enhancing the cooling effect.

[0030] The user can decide to adopt the structural design of the first or second preferred embodiment according to the material and dimensions of the collet 80, the number of front slots 21, and the number of rear slots 22 to achieve a collet 80 with adequate structural strength and exhibit an appropriate cooling effect. Thus, the design of the collet according to the utility model is not limited to specific preferred embodiments.

[0031] Furthermore, in the first and second preferred embodiments, the respective inner coolant groove 30, 30A and the corresponding outer coolant bore 40, 40A are each connected to the one corresponding rear slot 22. For example, in further embodiments, if the rear slots 22 of the collet 80 are arranged closer together and in greater number, it is possible for the respective inner coolant groove and the corresponding outer coolant bore to be connected to two or more of the rear slots 22. In this way, paths for the flow of the coolant can also be formed. Thus, the design of the collet according to the utility model is not limited to the first and second preferred embodiments with regard to the coolant flow path.

[0032] Although the present utility model has been described in detail using exemplary embodiments, it is obvious to those skilled in the art that the utility model is not limited to these exemplary embodiments. Rather, modifications are possible such that individual features can be omitted or different combinations of features can be implemented without exceeding the scope of the appended claims. The disclosure of the present utility model includes all combinations of the individual features presented. List of reference symbols 10 collet main body 11 Front end 12 Rear end 13 through hole 21 front slot 22 rear slot 30, 30A inner coolant channel 40, 40A outer coolant hole 80, 80A collet 91 spindle 92 Tool holder main body 93 Mother 94 tools 95 Coolant channel A cutting line B Cutting line C Center line D hole diameter E Length of the protruding tool section G Distance θ included angle

Claims

[1] Collet with improved cooling effect, comprising: - a collet main body (10) having a center line (C), a front end (11) and a rear end (12) and including a through hole (13) extending along the center line (C); - a plurality of slots extending from the outer periphery of the collet main body (10) through the collet main body (10) and opening into the through hole (13) and comprising a plurality of front slots (21) and a plurality of rear slots (22), wherein the front slots (21) extend from the front end (11) of the collet main body (10) towards the rear end (12) thereof and the rear slots (22) extend from the rear end (12) of the collet main body (10) towards the front end (11) thereof; - at least one inner coolant groove (30, 30A) which is recessed on the inner surface of the through hole (13) and extends from the front end (11) of the collet main body (10) toward the rear end (12) thereof so as to communicate with the rear slots (22); and - at least one outer coolant bore (40, 40A) which is arranged at a distance from the through hole (13) and extends from the front end (11) of the collet main body (10) towards the rear end (12) thereof so as to communicate with the rear slots (22), the outer coolant bore (40, 40A) being directed towards the front end (11) of the collet main body (10) and successively inclining towards the centre line (C) of the collet main body (10). [2] Collet according to claim 1, characterized byin that the collet chuck (80) comprises a plurality of inner coolant grooves (30) and a plurality of outer coolant bores (40), wherein the inner coolant grooves (30, 30A) are arranged around the through-hole (13), wherein the respective inner coolant groove (30) is connected to the one corresponding rear slot (22), wherein the outer coolant bores (40) are arranged around the through-hole (13), wherein the respective outer coolant bore (40) is connected to the one corresponding rear slot (22). [3] Collet according to claim 2, characterized by that the inner coolant channels (30) and the outer coolant bores (40) are arranged offset from one another around the through hole (13). [4] Collet according to claim 2, characterized bythat the respective inner coolant groove (30A) and the corresponding outer coolant bore (40A) are connected to each other by means of the corresponding rear slot (22). [5] Collet according to one of claims 2 to 4, characterized by that the inner coolant channels (30) are arranged at an equal angle to one another around the through hole (13). [6] Collet according to one of claims 2 to 4, characterized by that the outer coolant holes (40) are arranged at an equal angle to one another around the through hole (13). [7] Collet according to one of claims 1 to 4, characterized bythat there is a distance (G) between the inner surface of the outer coolant bore (40) and the inner surface of the through hole (13), the through hole (13) having a hole diameter (D), an included angle (θ) existing between the outer coolant bore (40) and the center line (C) of the collet main body (10), the tangent value of the included angle (θ) being one-quarter of the value obtained by dividing the distance (G) by the hole diameter (D).

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