Quick-change tool apron assembly

Abstract

The quick-change tool apron assembly comprises a base, a tool apron and a tool bit which are sequentially connected, a tool bit installation body is arranged on the side, close to the tool bit, of the tool apron, an insertion rod is arranged on the side, close to the base, of the tool apron, the tool bit is detachably installed on the tool bit installation body, and the insertion rod is embedded into a base installation hole formed in the base and detachably connected with the base; the insertion rod comprises a first straight rod part, a conical rod part and a second straight rod part from top to bottom, wherein the outer diameters of the first straight rod part, the conical rod part and the second straight rod part are sequentially reduced. The base mounting hole comprises a first straight cylinder part, a first conical cylinder part and a second straight cylinder part from top to bottom, wherein the inner diameters of the first straight cylinder part, the first conical cylinder part and the second straight cylinder part are sequentially reduced. The outer wall of the first straight rod part is attached to the inner wall of the first straight cylinder part, the outer wall of the conical rod part is in interference fit with the inner wall of the first conical cylinder part, the outer wall of the second straight rod part is attached to the outer wall of the second straight cylinder part, and static friction force locking is still maintained under high-frequency vibration. The locking device has the advantages that first-stage anti-rotation locking is achieved through interference fit, the critical value design that the taper angle is smaller than the friction angle meets the self-locking condition, and it is guaranteed that static friction force locking is still maintained without loosening under high-frequency vibration.

Description

Technical Field

[0001] This utility model relates to a quick-change tool holder assembly, belonging to the field of road machinery engineering technology. Background Technology

[0002] Milling machines are commonly used for road surface maintenance when problems such as boils and cracks appear. The principle is that the milling drum mounted at the bottom of the machine rotates, driving alloy cutters mounted on it to cut the damaged parts of the ground. After the waste is removed, the ground is repaired. Traditionally, the cutter head of the milling drum is directly mounted on the cutter holder, which is welded to the milling drum body. During operation, the cutter head rotates within the mounting hole of the cutter holder, allowing for even wear and longer working time. However, the lifespan of the cutter head is limited. After the cutter head is completely worn, the welded cutter holder may continue to wear. Replacing the cutter holder requires cutting it off and re-welding it, a time-consuming and labor-intensive process, and the on-site welding precision is difficult to guarantee. Therefore, a quick-change cutter holder structure is needed, separating the welded base from the cutter head and adding a transition cutter holder in between. This allows for quick replacement of the cutter head and its mounting holder while protecting the base from damage.

[0003] Existing Chinese patent application CN 117702592 A discloses a quick-change tool holder, milling drum, and milling machine. This application also proposes a milling machine tool holder that enables convenient tool head replacement. However, the disclosed content shows that the tool holder is locked by a limiting recess and a limiting hole on the base, which together achieve lateral limiting. The vertical limiting is achieved by a wedge-shaped pin that penetrates the base laterally and engages with a notch on the fixed shank. This structure achieves the limiting of the tool holder through the combination of these two methods. However, implementing this structure requires multiple drilling and cutting operations on the base, while also ensuring the machining accuracy of the fixed shank, which increases production costs. Therefore, in order to reduce production costs, it is currently necessary to provide a tool holder that can be stably installed and easily disassembled. Summary of the Invention

[0004] Purpose of the invention: To address the shortcomings of existing technologies, this utility model provides a quick-change tool holder assembly. Through the structural design of the insertion rod and the mounting hole of the base, the interference fit between the conical surfaces achieves locking, making disassembly and removal very convenient and simple.

[0005] Technical solution: A quick-change tool holder assembly includes a base, a tool holder, and a tool head connected in sequence. The tool holder has a tool head mounting body near the tool head and an insertion rod near the base. The tool head is detachably mounted on the tool head mounting body, and the insertion rod is inserted into a base mounting hole on the base and detachably connected to the base.

[0006] The insertion rod comprises, from top to bottom, a first straight rod section, a tapered rod section, and a second straight rod section, with the outer diameter decreasing sequentially. The base mounting hole comprises, from top to bottom, a first straight cylinder section, a first tapered cylinder section, and a second straight cylinder section, with the inner diameter decreasing sequentially. The outer wall of the first straight rod section fits against the inner wall of the first straight cylinder section. The outer wall of the tapered rod section and the inner wall of the first tapered cylinder section are interference-fitted. The outer wall of the second straight rod section fits against the outer wall of the second straight cylinder section. The cone angle of any cone surface is less than the critical value of the friction angle, ensuring that static friction locking is maintained even under high-frequency vibration.

[0007] This utility model achieves initial positioning during installation by matching the first straight rod part with the first straight cylinder part. The cone rod part and the first cone cylinder part are interference-fitted to achieve first-level anti-rotation locking. The cone angle design meets the self-locking condition. The cone angle is less than the critical value of the friction angle, ensuring that static friction locking is maintained under high-frequency vibration and ensuring that there is no loosening under vibration conditions.

[0008] The second straight section is provided with a second conical section near the first conical section, and a conical sleeve is fitted on the outer side of the second straight section at the position corresponding to the second conical section. The outer wall of the second straight section is interference-fitted with the inner wall of the second conical section, and the inner wall of the second straight section is interference-fitted with the outer wall of the second straight section.

[0009] To further enhance the stability of the inserted rod after installation and reduce the possibility of loosening, a tapered sleeve is fitted on the outside of the second straight rod. The bottom tapered surface of the base is interference-fitted with the outer tapered surface of the tapered sleeve. By striking the tool holder with a tool, the wedge sleeve generates a radial expansion force, achieving rigid locking between the tool holder and the mounting hole of the base. The tapered sleeve matches the inner wall of the second tapered cylinder to achieve a secondary anti-rotation locking, which, combined with the primary anti-rotation locking, achieves a more secure connection.

[0010] The base and the tool holder are provided with corresponding positioning holes, and a positioning shaft is provided in the positioning hole. The two ends of the positioning shaft are respectively embedded in the positioning holes on the base and the tool holder.

[0011] To further enhance the stability of the tool holder and base, prevent relative rotation, and ensure the safety and stability of the construction process.

[0012] The base is configured with a concave curved surface on the side near the tool holder, and the tool holder is configured with a raised curved support surface that mates with the concave curved surface on the side near the base. The concave curved surface and the curved support surface form a surface contact.

[0013] By setting the connecting surface to a curved surface, surface-to-surface contact is achieved, increasing the contact area by 50% to 70% compared to planar contact, which can effectively disperse the impact force of the cutter head.

[0014] The cutter head mounting body is located near the upper side of the cutter holder, and the angle between the axis of the cutter head mounting body and the axis of the insertion rod is α, where α is 5°~15°.

[0015] In order to enable the cutter head mounting body to generate a downward clamping force and have a good cutting angle, the working capacity can be effectively improved by setting the included angle between the cutter head mounting body and the insertion rod, so that the cutter head can continuously work in the high-efficiency range.

[0016] The maximum angle of the bending support surface is set to β, where β is between 120° and 130°.

[0017] To maximize the contact area between the tool holder and the base, the angle between the connecting surface of the curved support surface and the concave curved surface is set to increase the contact area. This allows the impact force on the tool holder during operation to be better dissipated onto the base, reducing the impact of working vibration on the installation stability of the tool head and preventing the tool head and tool holder from separating during operation.

[0018] The tool holder is provided with a tool head mounting hole that connects the tool holder and the tool head mounting body, and the central longitudinal axis of the tool head mounting hole intersects with the concave curved surface of the base.

[0019] The central longitudinal axis of the cutter head mounting hole intersects with the support surface of the base, and the mounting hole penetrates the base, so that the impact force is transmitted along the normal direction of the support surface, avoiding stress concentration caused by bending moment.

[0020] The cutter head mounting hole is provided with a discharge groove that expands in a direction away from the insertion shaft at one end near the base. A discharge groove is provided on the base at the position corresponding to the cutter head mounting hole, and the direction of the discharge groove is consistent with that of the discharge groove. The extension direction of the discharge groove forms an angle greater than 90° with the central axis of the cutter head mounting hole.

[0021] The base has a rearward discharge groove on the rear side relative to the working direction, which forms an obtuse angle with the central axis of the cutter head mounting hole, providing a channel for the rear side to enter the cutter head mounting hole for cutter head disassembly; at the same time, since the size of the opening at the discharge groove gradually increases rearward, the milling material mixture that enters during milling can be discharged more easily under the action of centrifugal force; when waste material accumulates here, it can also be cleaned very easily.

[0022] An annular sealing groove is provided at the junction of the base mounting hole and the tool holder, and a sealing ring is provided in the sealing groove.

[0023] The sealing ring is made of polyurethane-metal composite material and is embedded in the annular sealing groove at the junction of the base and the upper cutter holder. It can prevent mud, water and gravel particles from entering the inner hole of the base and protect the mounting hole of the base; absorb cutting impact vibration and reduce fretting wear between the tapered sleeve and the base.

[0024] Beneficial effects: This utility model achieves initial positioning during installation by matching the first straight rod part with the first straight cylinder part. The interference fit between the cone rod part and the first cone cylinder part achieves first-level anti-rotation locking. The cone angle design meets the self-locking condition. The cone angle is less than the critical value of the friction angle, ensuring that static friction locking is maintained under high-frequency vibration and ensuring that there is no loosening under vibration conditions.

[0025] To further enhance the stability of the inserted rod after installation and reduce the possibility of loosening, a tapered sleeve is fitted on the outside of the second straight rod. The bottom tapered surface of the base is interference-fitted with the outer tapered surface of the tapered sleeve. By striking the tool holder with a tool, the wedge sleeve generates a radial expansion force, achieving rigid locking between the tool holder and the mounting hole of the base. The tapered sleeve matches the inner wall of the second tapered cylinder to achieve a secondary anti-rotation locking, which, combined with the primary anti-rotation locking, achieves a more secure connection. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 This is the overall assembly drawing of this utility model.

[0028] Figure 2 This is an exploded view of the present invention.

[0029] Figure 3 This is a schematic diagram showing the curved surface angle and the relative angle between the mounting body and the insertion rod of this utility model.

[0030] Figure 4 This is a structural diagram of the tool holder of this utility model.

[0031] Figure 5 This is a structural diagram of the base of this utility model.

[0032] Figure 6 This is a cross-sectional view of the base of this utility model. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] like Figures 1 to 6 As shown, a quick-change tool holder assembly includes a base 1, a tool holder 2, and a tool head 3 connected in sequence. The tool holder 2 is provided with a tool head mounting body 4 near the tool head 3, and an insertion rod 5 is provided near the base 1. The tool head 3 is detachably mounted on the tool head mounting body 4, and the insertion rod 5 is inserted into a base mounting hole 6 opened on the base 1 and is detachably connected to the base 1.

[0037] The insertion rod 5 comprises, from top to bottom, a first straight rod portion 51, a tapered rod portion 52, and a second straight rod portion 53, with their outer diameters decreasing sequentially. The base mounting hole 6 comprises, from top to bottom, a first straight cylindrical portion 61, a first tapered cylindrical portion 62, and a second straight cylindrical portion 63, with their inner diameters decreasing sequentially. The outer wall of the first straight rod portion 51 is fitted to the inner wall of the first straight cylindrical portion 61. The outer wall of the tapered rod portion 52 is interference-fitted to the inner wall of the first tapered cylindrical portion 62. The outer wall of the second straight rod portion 53 is fitted to the outer wall of the second straight cylindrical portion 63. The cone angle of any cone surface is less than the critical value of the friction angle, ensuring that static friction locking is maintained even under high-frequency vibration.

[0038] This utility model achieves initial positioning during installation by matching the first straight rod portion 51 with the first straight cylinder portion 61. The cone rod portion 52 and the first cone cylinder portion 62 are interference-fitted to achieve first-level anti-rotation locking. The cone angle design meets the self-locking condition. The cone angle is less than the critical value of the friction angle, ensuring that static friction locking is maintained under high-frequency vibration and ensuring that there is no loosening under vibration conditions.

[0039] The second straight cylinder 63 is provided with a second conical cylinder 64 near the first conical cylinder 62. A conical sleeve 65 is fitted on the outer side of the second straight rod 53 at a position corresponding to the second conical cylinder 64. The outer wall of the sleeve is in an interference fit with the inner wall of the second conical cylinder 64, and the inner wall is in an interference fit with the outer wall of the second straight cylinder 63.

[0040] To further enhance the stability of the inserted rod 5 after installation and reduce the possibility of loosening, a tapered sleeve 65 is fitted on the outside of the second straight rod. The bottom tapered surface of the base 1 is interference-fitted with the outer tapered surface of the tapered sleeve 65. By striking the tool holder 2, the tapered sleeve 65 generates a radial expansion force, achieving a rigid lock between the tool holder 2 and the mounting hole 6 of the base. The tapered sleeve 65 matches the inner wall of the second tapered cylinder 64 to achieve a secondary anti-rotation lock, which, combined with the primary anti-rotation lock, achieves a more secure connection.

[0041] The base 1 and the tool holder 2 are provided with corresponding positioning holes 7. A positioning shaft 8 is provided in the positioning hole 7, and the two ends of the positioning shaft 8 are respectively embedded in the positioning holes 7 on the base 1 and the tool holder 2.

[0042] To further enhance the stability of the tool holder 2 and the base 1, and to further prevent relative rotation between them, thus ensuring the safety and stability of the construction process.

[0043] The base 1 is configured with a concave curved surface on the side near the tool holder 2, and the tool holder 2 is configured with a raised curved support surface that cooperates with the concave curved surface on the side near the base 1. The concave curved surface and the curved support surface form a surface contact.

[0044] By setting the connecting surface as a curved surface to achieve surface-to-surface contact, the contact area is increased by 50% to 70% compared to planar contact, which can effectively disperse the impact force of the cutter head 3.

[0045] The cutter head mounting body 4 is located near the upper side of the cutter holder 2. The angle between the axis of the cutter head mounting body 4 and the axis of the insertion rod 5 is α, where α is 5°~15°, and in this embodiment, it is 10°.

[0046] In order to enable the cutter head mounting body 4 to generate a downward clamping force and have a good cutting angle, the working capacity can be effectively improved by setting the included angle between the cutter head mounting body 4 and the insertion rod 5, so that the cutter head 3 can continue to work in the high-efficiency range.

[0047] The maximum angle of the bending support surface is set to β, which is 120°~130°. In this embodiment, it is 125°.

[0048] To maximize the contact area between the tool holder 2 and the base 1, the angle between the connecting surface of the curved support surface and the concave curved surface is set to increase the contact area. This allows the impact force on the tool holder during operation to be better dissipated onto the base 1, reducing the impact of working vibration on the installation stability of the tool head 3 and preventing the tool head 3 and tool holder 2 from separating during operation.

[0049] The tool holder 2 is provided with a tool head mounting hole 9 that passes through the tool holder 2 and communicates with the tool head mounting body 4. The central longitudinal axis of the tool head mounting hole 9 intersects with the concave curved surface of the base 1.

[0050] The central longitudinal axis of the cutter head mounting hole 9 intersects with the support surface of the base, and the mounting hole penetrates the base, so that the impact force is transmitted along the normal direction of the support surface, avoiding stress concentration caused by bending moment.

[0051] The cutter head mounting hole 9 is provided with a discharge groove 10 that expands away from the insertion shaft at one end near the base 1. The base 1 is provided with a discharge groove 11 that is consistent with the direction of the discharge groove 10 at the position corresponding to the cutter head mounting hole 9. The extension direction of the discharge groove 11 forms an angle greater than 90° with the central axis of the cutter head mounting hole 9.

[0052] The base 1 has a rearward discharge groove 11 on the rear side relative to the working direction, which forms an obtuse angle with the central axis of the cutter head mounting hole 9, providing a channel for the rear side to enter the cutter head mounting hole 9 for the removal of the cutter head 3; at the same time, since the size of the opening at the discharge groove 11 gradually increases rearward, the milling material mixture that enters during milling can be discharged more easily under the action of centrifugal force; when waste material accumulates here, it can also be cleaned very easily.

[0053] An annular sealing groove 12 is provided at the junction of the base mounting hole 6 and the tool holder 2, and a sealing ring 13 is provided in the sealing groove.

[0054] The sealing ring 13 is made of polyurethane-metal composite material and is embedded in the annular sealing groove 12 at the junction of the base 1 and the upper cutter holder 2. It can prevent mud, water and gravel particles from entering the inner hole of the base 1 and protect the mounting hole 6 of the base; absorb cutting impact vibration and reduce the fretting wear between the tapered sleeve 65 and the base 1.

[0055] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0056] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A quick change tool holder assembly characterized by: It includes a base (1), a cutter holder (2) and a cutter head (3) connected in sequence. The cutter holder (2) is provided with a cutter head mounting body (4) on the side near the cutter head (3) and an insertion rod (5) is provided on the side near the base (1). The cutter head (3) is detachably mounted on the cutter head mounting body (4). The insertion rod (5) is embedded in the base mounting hole (6) opened on the base (1) and is detachably connected to the base (1). The insertion rod (5) includes, from top to bottom, a first straight rod portion (51), a tapered rod portion (52), and a second straight rod portion (53) with successively smaller outer diameters. The base mounting hole (6) includes, from top to bottom, a first straight cylinder portion (61), a first tapered cylinder portion (62), and a second straight cylinder portion (63) with successively smaller inner diameters. The outer wall of the first straight rod portion (51) is fitted with the inner wall of the first straight cylinder portion (61). The outer wall of the tapered rod portion (52) is interference-fitted with the inner wall of the first tapered cylinder portion (62). The outer wall of the second straight rod portion (53) is fitted with the outer wall of the second straight cylinder portion (63). The cone angle of any cone surface is less than the critical value of the friction angle, ensuring that static friction locking is maintained under high-frequency vibration.

2. The quick change tool holder assembly of claim 1, wherein: The second straight cylinder (63) is provided with a second cone cylinder (64) near the first cone cylinder (62). A cone sleeve (65) is fitted on the outer side of the second straight rod (53) at the position corresponding to the second cone cylinder (64), with its outer wall interfering with the inner wall of the second cone cylinder (64) and its inner wall interfering with the outer wall of the second straight cylinder (63).

3. The quick change tool holder assembly of claim 1, wherein: The base (1) and the tool holder (2) are provided with corresponding positioning holes (7), and a positioning shaft (8) is provided in the positioning hole (7). The two ends of the positioning shaft (8) are respectively embedded in the positioning holes (7) on the base (1) and the tool holder (2).

4. The quick change tool holder assembly of claim 1, wherein: The base (1) is provided with a concave curved surface on the side near the tool holder (2), and the tool holder (2) is provided with a raised curved support surface that cooperates with the concave curved surface on the side near the base (1). The concave curved surface and the curved support surface form a surface contact.

5. The quick change tool holder assembly of claim 4, wherein: The cutter head mounting body (4) is located near the upper side of the cutter holder (2). The angle between the axis of the cutter head mounting body (4) and the axis of the insertion rod (5) is α, where α is 5°~15°.

6. The quick change tool holder assembly of claim 5, wherein: The maximum angle of the bending support surface is set to β, where β is between 120° and 130°.

7. The quick change tool holder assembly of claim 6, wherein: The tool holder (2) is provided with a tool head mounting hole (9) that passes through the tool holder (2) and communicates with the tool head mounting body (4). The central longitudinal axis of the tool head mounting hole (9) intersects with the concave curved surface of the base (1).

8. The quick change tool holder assembly of claim 7, wherein: The cutter head mounting hole (9) is provided with a discharge groove (10) that expands away from the insertion shaft at one end near the base (1). The base (1) is provided with a discharge groove (11) that is in the same direction as the discharge groove (10) at the position corresponding to the cutter head mounting hole (9). The extension direction of the discharge groove (11) forms an angle greater than 90° with the central axis of the cutter head mounting hole (9).

9. The quick change tool holder assembly of claim 2, wherein: An annular sealing groove (12) is provided at the junction of the base mounting hole (6) and the knife holder (2), and a sealing ring (13) is provided in the sealing groove.

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