Tool holder for a machine tool

Abstract

To provide a tool holder of a machine tool capable of securing accuracy of positioning and combination without damaging a bearing surface in a tool and an end surface in a tool receiving part in a process of removing the tool.SOLUTION: The tool holder includes a holder body and a tool locking mechanism, the holder body has a sleeve connecting hole for inserting a portion of the tool, the tool locking mechanism is disposed in the sleeve connecting hole and includes a shaft sleeve, a pushing block and at least one bearing ball, the shaft sleeve has a shaft hole and is provided with at least one ball joint in a radial direction, the pushing block is movably disposed in the shaft hole, and the pushing block limits the at least one bearing ball to the at least one ball joint.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a machining tool for a machine tool, and more particularly to a tool holder for a machine tool. [Background technology]

[0002] A known tool magazine for a machine tool includes a plurality of tool receiving sections for mounting or inserting tools, and tools of different specifications are fixedly mounted on each tool. To stabilize the tool and prevent it from unduly loosening from the tool receiving section and being damaged, the known tool receiving section typically includes an internal engagement limiting structure. The engagement limiting structure prevents the tool from unduly loosening by providing abutment and engagement with one end of the tool mounted or inserted into the tool receiving section. The engagement limiting structure includes a plurality of radial holes disposed at the rear of the tool receiving section, each of which is fitted with a bearing ball and a spring. The springs allow the bearing balls to be inserted into the tool receiving section by applying a radial force to the bearing balls, forcing them to abut against the tool and inserting it into the tool receiving section, thereby enabling the tool to be mounted or inserted into the tool receiving section stably.

[0003] In the above-described engagement limiting configuration, a spring with a relatively high material stiffness is typically selected to enhance the stability of attaching or inserting a tool into the tool receiving portion. However, this selection requires a relatively large pulling force to overcome the spring's elasticity when removing the tool. As a result, if there is a problem with controlling the force during removal, the operator may make a mistake and be injured. To avoid this problem, a currently used configuration is shown in FIGS. 1 and 2. In this configuration, the operator generally inserts an auxiliary tool (e.g., a tool removal wrench 1) into a gap G reserved in advance at a specific location between the tool 2 and the tool receiving portion 3, and then, as shown in FIG. 3, the tool removal wrench 1 forces the tool 2 away from the tool receiving portion 3. Although the above configuration allows the tool 2 to be easily removed, the portion of the wrench 1 used to remove the tool that is inserted into the gap G is likely to cause wear to the bearing surface 2a of the tool 2 and the end face 3a of the tool receiving portion 3. If this continues for a long period of time, it will indirectly affect the accuracy of subsequent alignment and assembly. In particular, when the tool 2 is coupled to the spindle of a machining center device, the worn bearing surface 2a may affect the stability of coupling the tool 2 to the spindle. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of this, an object of the present invention is to provide a tool holder for a machine tool that can ensure the accuracy of alignment and assembly during the process of removing the tool without damaging the bearing surface of the tool or the end face of the tool receiving portion. [Means for solving the problem]

[0005] To achieve the above object, the present invention provides a tool holder for a machine tool for storing a tool having an end portion. The tool holder includes a holder body and a tool locking means. The holder body has a sleeve connecting hole and at least one side hole, and defines an axis passing through the center of the sleeve connecting hole. The tool advances through the sleeve connecting hole along the axis, and the at least one side hole communicates with the sleeve connecting hole. The tool locking means is installed in the sleeve connecting hole of the holder body and includes a shaft sleeve, a push-up block, and at least one bearing ball. The shaft sleeve has an axial hole, at least one ball joint, and at least one slot, the axis passing through the axial hole, the at least one ball joint communicating with the axial hole and the sleeve connecting hole, and the at least one slot communicating with the axial hole and the at least one side hole. The push-up block is installed in the axial hole of the shaft sleeve and is movable along the axis between a first position and a second position. The at least one bearing ball is received in the at least one ball joint and is movable between a third position and a fourth position. [Effects of the Invention]

[0006] The effect of the present invention is that when a portion of the tool is attached or inserted into the sleeve connection hole in the holder body and the push-up block is positioned in the first position, the at least one bearing ball is restricted to the third position and abuts against the end of the tool, thereby restricting the tool from withdrawing from the sleeve connection hole, while when the push-up block is positioned in the second position, the at least one bearing ball moves to the fourth position, allowing the tool to move away from the sleeve connection hole. [Brief explanation of the drawings]

[0007] [Figure 1]FIG. 1 is a perspective view showing a conventional machine tool tool magazine using a wrench for removing a tool; [Figure 2] 2 is a locally enlarged view of the tool magazine shown in FIG. 1 viewed from another viewing angle. [Figure 3] 2 is a schematic diagram showing a state in which a tool is removed from the tool magazine shown in FIG. 1 by a tool removal wrench. FIG. [Figure 4] 1 is a perspective view showing a tool holder and a tool of a machine tool according to a preferred embodiment of the present invention. FIG. [Figure 5] FIG. 5 is an exploded view of the tool holder shown in FIG. 4. [Figure 6] FIG. 6 is a schematic view of the tool holder shown in FIG. 5 as viewed from another viewing angle. [Figure 7] FIG. 5 is a front view showing the tool holder shown in FIG. 4. [Figure 8] 8 is a cross-sectional view taken along the line 8-8 in FIG. 7. [Figure 9] FIG. 5 is a cross-sectional view showing the attachment of the tool shown in FIG. 4 to a tool holder. [Figure 10] 9, showing the tool in a locked state. [Figure 11] FIG. 10 is a perspective view showing the tool in a locked state and the operating part in use. [Figure 12] FIG. 10 is a side view showing a preparatory operation when removing a tool using the operating unit. [Figure 13] 13 is a cross-sectional view showing one end of the operating portion shown in FIG. 12 extending into a ring-shaped groove in the push-up block. FIG. [Figure 14] 14 is a view similar to FIG. 13, showing the operation of removing the tool by pulling the operating portion. [Figure 15] FIG. 10 is a front view showing a tool holder and a tool according to another preferred embodiment of the present invention. [Figure 16] 16 is a cross-sectional view taken along the line 16-16 in FIG. 15. DETAILED DESCRIPTION OF THE INVENTION

[0008] To more clearly explain the present invention, a preferred embodiment will be described in detail below with reference to the drawings. As shown in FIGS. 4 to 6, a machine tool tool holder 100 according to a preferred embodiment of the present invention is applied to a disk-type tool magazine, but is not limited to this. The tool holder 100 stabilizes a tool 200 and allows the tool 200 to be easily removed. The tool 200 has one end for fixing a tool (not shown) and the other end for providing an end portion. In this embodiment, the end portion is formed by an annular enclosure 201, and an inwardly protruding lip portion 202 is formed on the edge of the annular enclosure 201, and an engaging surface 202a (see FIG. 9) is formed on the inner wall of the inwardly protruding lip portion 202.

[0009] The tool holder 100 according to this embodiment includes a holder body 10 and a tool locking means 20. The holder body 10 has an attachment portion 12 and a sleeve joint 14. One end of the attachment portion 12 is pin-connected to a machine body (not shown) of a machine tool, and the other end is connected to the sleeve joint 14. The sleeve joint 14 has a sleeve connecting hole 14a recessed from an end face 10a and at least one side hole 14b located in a side wall. When an axis L passing through the center of the sleeve connecting hole 14a is defined, the tool 200 advances through the sleeve connecting hole 14a along the axis L. The at least one side hole 14b is an elongated hole and communicates with the sleeve connecting hole 14a. In this embodiment, there is only one side hole 14b, and the sleeve joint 14 further has two through holes 14c at its rear end that communicate with the sleeve connecting hole 14a.

[0010] The tool locking means 20 is installed in the sleeve connecting hole 14a of the holder body 10, and includes a shaft sleeve 21, a limiting part 22, a spring 23, a push-up block 24, and at least one bearing ball 25. The detailed structure and relative position of each part will be described below.

[0011] 6 to 8, the shaft sleeve 21 is a cylinder having an axial hole 21a, two locking holes 21b arranged along the axial direction, and one threaded hole 21c at its tail end. The axial hole 21a and the threaded hole 21c are connected to each other and located on the axis L. The shaft sleeve 21 also has at least one ball joint 21d and at least one slot 21e arranged radially therein. In this embodiment, the shaft sleeve 21 is composed of a small diameter portion 211 and a large diameter portion 212, and the outer diameter of the small diameter portion 211 is smaller than the outer diameter of the large diameter portion 212. The at least one ball joint 21d is located in the small diameter portion 211, and the at least one slot 21e is located in the large diameter portion 212. The shaft sleeve 21 is fixed to the holder body 10 and positioned in the sleeve connecting hole 14a when two bolts 26 are inserted through the through holes 14c and locked into the locking holes 21b. At the same time, the at least one ball joint 21d communicates with the shaft hole 21a and the sleeve connecting hole 14a, and the at least one slot 21e communicates with the shaft hole 21a and the at least one side hole 14b. Preferably, there are three ball joints 21d, distributed around the circumference. There is one slot 21e, cut along the circumference. As shown in FIG. 8, a space S formed between the outer circumferential surface of the small-diameter portion 211 of the shaft sleeve 21 and the inner wall surface of the sleeve connecting hole 14a of the holder body 10 is for the annular enclosure 201 of the tool 200 to be inserted into.

[0012] The limiting portion 22 has a threaded rod 22a that is locked into the threaded hole 21c of the shaft sleeve 21 so that the lock depth can be adjusted, and one end of the threaded rod 22a extends into the axial hole 21a and forms a contact portion 22b. In this embodiment, the limiting portion 22 is a hexagonal socket head screw. The spring 23 is installed in the axial hole 21a of the shaft sleeve 21 and is fitted onto the threaded rod 22a of the limiting portion 22. One end of the spring 23 abuts against the hole bottom 21f of the axial hole 21a.

[0013] The push-up block 24 is installed in the axial hole 21a of the shaft sleeve 21 and is movable along the axis L. The push-up block 24 is a generally cylindrical body having an inclined push-up surface 24a at its front end and a contacted portion 24b formed with a flat end surface at its rear end. The other end of the spring 23 abuts against the contacted portion 24b, and the elastic force of the spring 23 urges the push-up block 24 to move outward. The push-up block 24 has a recessed portion on its outer circumferential surface, which corresponds to the slot 21e in the shaft sleeve 21. In this embodiment, the recessed portion is an annular groove 24c recessed along the circumferential surface of the push-up block 24.

[0014] The at least one bearing ball 25 is three in number to match the ball joint 21d of this embodiment. After the push-up block 24 is inserted into the shaft hole 21a, the plurality of bearing balls 25 are installed one by one in the corresponding ball joint 21d of the shaft sleeve 21. The elastic force of the spring 23 keeps the push-up surface 24a of the push-up block 24 in contact with the bearing ball 25 and pushes the plurality of bearing balls 25 outward in the radial direction. As shown in FIG. 8, some surfaces of the plurality of bearing balls 25 are close to the spherical surface of the ball joint 21d, while other surfaces of the bearing balls 25 protrude into the space S. When so defined, the push-up block 24 in this state is located at the first position P1, the bearing ball 25 is located at the third position P3, and the gap distance between the groove wall 21g in the groove hole 21e (i.e., the bearing surface defined in the present invention) and the groove wall 24d in the annular groove 24c (i.e., the push surface defined in the present invention) becomes the first gap distance G1.

[0015] 9, when the tool 200 is attached to or inserted into the tool holder 100, the annular enclosure 201 is first inserted into the space S between the holder body 10 and the shaft sleeve 21, and then the inwardly protruding lip 202 pushes each of the bearing balls 25 toward the axis L while moving away from the third position P3. At the same time, the bearing balls 25 push the push-up block 24 toward the limiting portion 22 from the first position P1. When the contacted portion 24b of the push-up block 24 contacts the contact portion 22b of the limiting portion 22, the push-up block 24 is defined as being located at the second position P2. At this time, the position of the push-up block 24 can be ensured so that the push-up surface 24a thereof maintains contact with the plurality of bearing balls 25, preventing the bearing balls 25 from unduly dropping from the ball joint 21d where they are located. With this definition, the bearing balls 25 in this state are located at the fourth position P4, and the push-up block 24 simultaneously pushes out the springs 23 so as to deform, increasing the gap between the groove wall 21g and the groove wall 24d to the second gap G2.

[0016] As the tool 200 continues to be inserted into the tool holder 100, when its inwardly protruding lip 202 passes the bearing ball 25, the push-up block 24 is pushed up by the spring 23 and quickly returns from the second position P2 to the first position P1, as shown in FIG. 10 . The gap between the groove wall 21g and the groove wall 24d is restored to the first gap G1, and the distance between the contacted portion 24b of the push-up block 24 and the contact portion 22b of the limiting portion 22 is maintained. At the same time, the push-up surface 24a of the push-up block 24 pushes the bearing ball 25, which is located at the fourth position P4, outward and returns to the third position P3. At the same time, the bearing ball 25 abuts against the push-up surface 24a of the push-up block 24 and the engagement surface 202a of the inwardly protruding lip 202 of the tool 200. As described above, the tool 200 is firmly coupled to the tool holder 100 and is prevented from unexpectedly withdrawing from the sleeve connecting hole 14a.

[0017] When attempting to remove the tool 200, the push-up block 24 is pushed toward the second position P2, and when the bearing balls 25 are loosened, the tool 200 can be easily removed from the tool holder 100. This tool removal method does not damage the end surface 10a of the holder body 10 or the bearing surface 203 of the tool 200 corresponding to the end surface 10a. In an application example, the push-up block 24 is pushed using an operating unit provided by the present invention. As shown in FIG. 11 , the operating unit 30 has a wide portion 32 and a narrow portion 34. The wide portion 32 is designed to facilitate pick-up by an operator, and the narrow portion 34 is connected to the wide portion 32 and has a front edge 34a and a rear edge 34b that face rearward from each other. 12 and 13, the elongated portion 34 of the operating unit 30 passes through the side hole 14b and the slot 21e, and one end of the elongated portion 34 is inserted into the annular groove 24c. As shown in FIG. 14, when the operating unit 30 is pulled, the operating unit 30 uses the portion of the front edge 34a that abuts against the groove wall 21g (i.e., the bearing surface) as a fulcrum and the portion of the rear edge 34b that contacts the groove wall 24d (i.e., the pushing surface) as a functional end. Based on the principle of leverage, the operating unit 30 pushes the push-up block 24 toward the second position P2 with the functional end, and the bearing ball 25 becomes loose. As described above, the operator can easily withdraw the tool 200 from the tool holder 100. Moreover, in this process, the end surface 10a of the holder body 10 and the bearing surface 203 of the tool 200 are not damaged, which ensures precision in assembly. After the operating part 30 is removed, the tool holder 100 is restored to the state shown in FIG. 8, ready for the next attachment or insertion of the tool 200.

[0018] The operating unit 30 in the above embodiment pushes the push-up block 24 toward the second position P2 based on the principle of leverage. However, in practice, the width of the elongated portion of the operating unit may be selected to be slightly larger than the first gap distance G1, and the elongated portion may be directly inserted into the side hole 14b, the slot 21e, and the annular groove 24c. This also pushes the push-up block 24 toward the second position P2, loosening the bearing ball 25, allowing the operator to easily remove the tool 200.

[0019] In the above embodiment, the configuration for preventing the bearing ball 25 from unduly dropping from the ball joint 21d due to the push-up block 24 being retracted further is achieved by locking the limiting portion 22 behind the push-up block 24 and positioning it axially. To achieve this objective, the present invention may employ other embodiments shown in FIGS. 15 and 16. Differences from the configurations of the above embodiments will be described below. Specifically, the shaft sleeve 40 shown in FIG. 16 has an axially disposed axial hole 42, and the shaft sleeve 40 has a threaded hole 44 that radially communicates with the axial hole 42. The limiting portion 46 is a setscrew that is locked in the threaded hole 44. A portion of the setscrew is positioned in the axial hole 42 and forms a contact portion 46a. The push-up block 48 has a contacted portion 48a formed as an enclosure at its rear end. The push-up block 48 can be pressed directly by the operating part or indirectly when attaching or inserting the tool 200, and when the contact part 46a abuts against the contacted part 48a, the push-up block 48 stops moving, ensuring that the bearing ball 25 does not fall from the ball joint 21d.

[0020] The above description is merely a preferred embodiment of the present invention, and any equivalent substitutions that apply to the patent scope together with the specification of the present invention should be included in the patent scope of the present invention. [Explanation of symbols]

[0021] 100 Tool Holders 10 Holder body 10a end face 12 Mounting part 14 Sleeve joint 14a Sleeve connection hole 14b Side hole 14c through hole 20 Tool locking means 21 Shaft sleeve 211 Small diameter section 212 Large diameter section 21a shaft hole 21b Lock hole 21c Threaded hole 21d ball joint 21e slot 21f hole bottom 21g groove wall 22 Restrictions 22a threaded rod 22b Contact part 23 Spring 24 Push-up Block 24a Push-up surface 24b Contacted part 24c annular groove 24d groove wall 25 bearing balls 26 volts 30 Control section 32 Wide section 34 Elongated part 34a Forward edge 34b Posterior edge 40 Shaft sleeve 42 shaft hole 44 screw holes 46 Restricted Section 46a Contact part 48 Push-up Block 48a Contacted part 200 Tools 201 Circular Enclosure 202 Medial protrusion lip 202a Engagement surface 203 Bearing surface L-axis G1 First Interval Distance G2 Second Interval Distance P1 First Position P2 Second Position P3 Third Position P4 Fourth Position S Space

Claims

1. 1. A tool holder for a machine tool for receiving a tool having an end, comprising: a holder body and a tool locking means; the holder body has a sleeve connection hole and at least one side hole, and defines an axis passing through the center of the sleeve connection hole, and when the tool advances through the sleeve connection hole along the axis, the at least one side hole communicates with the sleeve connection hole; the tool locking means is installed in the sleeve connecting hole of the holder body and includes a shaft sleeve, a push-up block and at least one bearing ball, the shaft sleeve has an axial hole, at least one ball joint and at least one slot, the axis passes through the axial hole, the at least one ball joint communicates with the axial hole and the sleeve connecting hole, the at least one slot communicates with the axial hole and the at least one side hole, the push-up block is installed in the axial hole of the shaft sleeve and is movable along the axis between a first position and a second position, the at least one bearing ball is housed in the at least one ball joint and is movable between a third position and a fourth position, A tool holder for a machine tool, wherein a portion of the tool is attached and inserted into the sleeve connection hole in the holder body, and when the push-up block is positioned at the first position, the at least one bearing ball is limited to the third position and abuts against the end of the tool, thereby preventing the tool from withdrawing from the sleeve connection hole, while when the push-up block is positioned at the second position, the at least one bearing ball moves to the fourth position, allowing the tool to withdraw from the sleeve connection hole.

2. Including an operation unit, 2. The tool holder of a machine tool according to claim 1, wherein the operating portion has a functional end portion that is inserted into the at least one side hole and the at least one slot hole and contacts the push-up block, and when the operating portion is controlled, the functional end portion pushes the push-up block to move to the second position.

3. The tool holder for a machine tool according to claim 2 , wherein the push-up block has a recessed portion on its outer circumferential surface, and the functional end portion of the operating portion is insertable into the recessed portion.

4. the at least one slot in the shaft sleeve has a bearing surface, and the recess in the push-up block has a push-up surface; the operating portion has an elongated portion insertable into the at least one side hole, the at least one slot, and the recess, the elongated portion having the functional end portion; 4. The tool holder for a machine tool according to claim 3, wherein the operating portion abuts the functional end against the pushing surface, with the point of the bearing surface that is in contact with the elongated portion as a fulcrum, and when the operating portion is pulled, the pushing block is pushed to move to the second position.

5. 5. A tool holder for a machine tool according to claim 3 or 4, wherein the at least one slot in the shaft sleeve is cut into the circumferential surface, and the recess in the push-up block is an annular groove configured to be recessed into the circumferential surface, and the annular groove corresponds to the at least one slot.

6. 2. The tool holder of a machine tool according to claim 1, wherein the shaft sleeve has a small diameter portion and a large diameter portion, the at least one ball joint being disposed radially on the small diameter portion, and the at least one slot being disposed radially on the large diameter portion.

7. the tool locking means includes a limiting portion, the limiting portion being coupled to the shaft sleeve and having a contact portion; 7. A tool holder for a machine tool according to claim 6, wherein the push-up block has a push-up surface at a front end and a contacted portion at a rear end, holds the push-up surface and the at least one bearing ball so as to be in contact with each other, and when the contacted portion and the contact portion are in contact with each other, the push-up block is located at the second position.

8. The shaft sleeve has a threaded hole communicating with the axial hole, and the axis passes through the threaded hole.

8. The tool holder for a machine tool according to claim 7, wherein the limiting portion has a threaded rod locked in the threaded hole, one end of the threaded rod located in the axial hole constitutes the contacting portion, and the push-up block has an end face at its rear end that constitutes the contacted portion.

9. The shaft sleeve has a threaded hole communicating with the axial hole, and the threaded hole is positioned in a radial direction.

8. The tool holder for a machine tool according to claim 7, wherein the limiting portion has a set screw locked in the threaded hole, a portion of the set screw located in the axial hole forms the contacting portion, and the push-up block has an enclosure at its rear end that forms the contacted portion.

10. the tool locking means includes a spring, and the axial hole in the shaft sleeve has a hole bottom; 2. A tool holder for a machine tool according to claim 1, wherein the spring is installed in the axial hole, one end of the spring abutting against the bottom of the hole and the other end of the spring abutting against the push-up block, and the elastic force of the spring keeps the push-up block moving to the first position.

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