A drilling and milling fixture for machining centers

Abstract

This utility model provides a drilling and milling fixture for machining centers, belonging to the field of machining technology. It solves the problems of insufficient coaxiality and precision in existing drilling and milling fixtures. This utility model includes a mounting plate, a connecting plate, and several drilling and milling fixtures. The connecting plate is fixedly mounted on the upper part of the mounting plate. A tension drum assembly is fixedly mounted inside the positioning cover. The tension drum assembly includes a tensioning area, a connecting area, and a transmission area. An elastic chuck is installed inside the tension drum assembly and is located within the tensioning area and the connecting area. A connecting flange is installed inside the tensioning area, with its lower end extending into the elastic chuck. The lower end of the tension drum assembly extends into the connecting hole and connects to the connecting plate. A guide post passes through a limiting hole and connects to the lower end of the positioning cover. The lower end of the guide post is fixedly connected to the transmission clamping block. This utility model has the advantage of high clamping precision.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical processing technology and relates to a drilling and milling fixture for machining centers. Background Technology

[0002] Drilling and milling fixtures are devices used in machining to position and clamp workpieces to ensure the accuracy of drilling, milling, and other machining processes. Drilling and milling fixtures restrict the workpiece's degrees of freedom through positioning elements, apply force to fix the workpiece through clamping devices, and provide support through the fixture body, thus realizing closed-loop control of positioning and clamping machining.

[0003] Chinese patent publication number CN206898851U discloses a special fixture for drilling and milling planes using a support in a machining center. It has an upper worktable and a base plate at its upper and lower parts, respectively. The upper worktable is mounted on the base plate via foot posts. Several clamping bodies are provided on the upper worktable, each with a drum at its upper part and a lifting cylinder at its lower part. The lifting cylinder is installed in the gap between the upper worktable and the base plate. The extension piston of the lifting cylinder is connected to the drum via a connecting rod, and the lifting cylinder drives the drum to move up and down via the connecting rod. A spring collet is provided around the outer ring of the drum, and a positioning seat is provided outside the spring collet. The up-and-down movement of the drum causes the spring collet to open outwards, allowing a workpiece support to be placed inside the spring collet. The spring collet clamps the workpiece support. A positioning pin is provided next to each clamping body, and the positioning hole of the workpiece support fits onto the positioning pin to achieve workpiece support positioning.

[0004] In the special fixture for drilling and milling planes for machining centers provided by this patent, the connecting rod is directly connected to the expansion drum and the axial movement of the expansion drum is directly controlled by the lifting cylinder. However, the connecting rod lacks a limiting device and is prone to displacement after long-term use, resulting in insufficient coaxiality and accuracy. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems in the prior art by providing a drilling and milling fixture for machining centers.

[0006] The objective of this utility model can be achieved through the following technical solution: A drilling and milling fixture for a machining center includes a mounting plate, a connecting plate, and several drilling and milling fixtures. The connecting plate is fixedly mounted on the upper end of the mounting plate. Each drilling and milling fixture includes a positioning cover, a expansion drum assembly, a connecting flange, an elastic chuck, a transmission clamping block, a guide column, and a drive cylinder. The positioning cover is annular, and the expansion drum assembly is fixedly mounted inside the positioning cover. The expansion drum assembly is integrally formed and is a multi-layered stepped cylinder. The expansion drum assembly includes a tensioning area, a connecting area, and a transmission area. The elastic chuck is installed inside the expansion drum assembly. The elastic clamp is located inside the tensioning area and the connecting area. The connecting flange is installed inside the tensioning area and its lower end extends into the elastic clamp. The connecting plate has several connecting holes and limiting holes. The lower end of the expansion drum assembly extends into the connecting hole and is connected to the connecting plate. The guide post passes through the limiting hole and is connected to the lower end of the positioning cover. The lower end of the guide post is fixedly connected to the transmission clamping block. The mounting plate has several mounting holes. The driving cylinder is fixedly connected to the mounting plate at the lower end of the mounting hole. The lower end of the transmission clamping block forms a transmission rod, which is connected to the driving cylinder.

[0007] In the aforementioned drilling and milling fixture for a machining center, the upper end of the transmission clamping block is triangular in shape and has a conical surface structure in the upper end.

[0008] In the aforementioned drilling and milling fixture for a machining center, a buffer cavity is formed between the tensioning area of ​​the expansion drum assembly and the interior of the positioning cover.

[0009] In the aforementioned drilling and milling fixture for a machining center, several zero-point positioners are fixedly mounted on the mounting plate.

[0010] In the aforementioned drilling and milling fixture for a machining center, a threaded hole is provided in the transmission zone of the expansion drum assembly.

[0011] Compared with the prior art, the drilling and milling fixture for machining centers provided by this utility model has the following beneficial effects: the guide post passes through the limiting hole of the connecting plate and its lower end is fixedly connected to the transmission clamping block. The limiting hole constrains the radial displacement of the guide post. The transmission clamping block moves linearly along the axis of the guide post under the action of the driving cylinder, eliminating transmission wobbling, ensuring that the clamping action is without deviation, avoiding the loss of clamping accuracy caused by transmission wobbling, and significantly improving the positional accuracy of drilling and milling. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0013] Figure 2 This is a partial cross-sectional structural diagram of the present invention;

[0014] Figure 3 This is a schematic diagram of the exploded structure of a drilling and milling fixture.

[0015] In the diagram: 1. Mounting platform; 11. Mounting hole; 2. Connecting platform; 21. Connecting hole; 22. Limiting hole; 3. Drilling and milling fixture; 31. Positioning cover; 311. Buffer chamber; 32. Expansion drum assembly; 321. Tensioning area; 322. Connecting area; 323. Transmission area; 324. Threaded hole; 33. Connecting flange; 34. Elastic chuck; 35. Transmission clamping block; 351. Transmission rod; 352. Conical structure; 36. Guide column; 37. Drive cylinder; 4. Zero point positioner. Detailed Implementation

[0016] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0017] like Figures 1 to 3 As shown, this embodiment includes a mounting plate 1, a connecting plate 2, several drilling and milling fixtures 3, and zero-point locators 4. The mounting plate 1 has a rectangular flat plate structure. The upper surface of the mounting plate 1 has several evenly distributed mounting holes 11, and the lower surface can be directly connected to the machining center worktable through bolts, forming the basic support platform of the fixture system. The connecting plate 2 is vertically fixed to the upper end face of the mounting plate 1 by bolts. Its surface has connecting holes 21 and limiting holes 22 that are adapted to the drilling and milling fixtures 3, forming a middle-level positioning reference to ensure the positional accuracy of each drilling and milling fixture 3. There are eight drilling and milling fixtures 3, which are connected to the connecting plate 2 and the mounting plate 1 in sequence. The upper surface edge of the mounting plate 1 is fixed with four sets of zero-point locators 4 by bolts. Their positioning pins are precisely matched with the positioning holes of the machining center worktable, realizing the quick change of the fixture system without manual tool setting, and greatly shortening the changeover time.

[0018] like Figures 1 to 3As shown, a single drilling and milling fixture 3 consists of a positioning cover 31, a expansion drum assembly 32, a connecting flange 33, an elastic chuck 34, a transmission clamping block 35, a guide post 36, and a drive cylinder 37. The positioning cover 31 is an annular shell, and its inner wall is interference-fitted with the expansion drum assembly 32 to form a closed tensioning cavity. The expansion drum assembly 32 is an integrally formed multi-layered stepped cylindrical structure, divided from top to bottom into a tensioning area 321, a connecting area 322, and a transmission area 323. The outer diameter of the tensioning area 321 is precisely fitted with the inner wall of the positioning cover 31 to install the elastic chuck 34 and achieve radial tensioning. The connecting area 322 is a central transition structure, and its inner hole slides with the outer diameter of the elastic chuck 34. In order to transmit tension force, the transmission zone 323 is a lower cylindrical body with a tapered guide structure on its outer surface that mates with the transmission clamping block 35. The inner hole has a threaded hole 324. The elastic chuck 34 is installed inside the expansion drum assembly 32, with its upper end located in the tension zone 321 and its lower end extending to the connection zone 322. The elastic chuck 34 mates with the inner wall of the tension zone 321 of the expansion drum assembly 32. When subjected to radial compression, it can elastically expand and hold the outer circle of the workpiece. The connecting flange 33 is a ring-shaped part that is fixed to the lower end of the tension zone 321 by bolts. Its inner diameter is smaller than the outer diameter of the elastic chuck 34, and its lower end face abuts against the upper end face of the elastic chuck 34 to help limit the axial displacement of the chuck and enhance the positioning accuracy.

[0019] like Figures 1 to 3 As shown, the guide post 36 consists of three symmetrically arranged cylindrical guide rods. The upper end is fixed to the lower end face of the positioning cover 31 by a pin, and the lower end passes through the limiting hole 22 of the connecting plate 2 and is bolted to the transmission clamping block 35 to form a rigid transmission mechanism, ensuring that the positioning cover 31 and the transmission clamping block 35 move synchronously. The drive cylinder 37 is fixed to the lower end of the mounting hole 11 of the mounting plate 1 by a flange. The piston rod extends upward and is threadedly connected to the transmission rod 351 at the lower end of the transmission clamping block 35. When the drive cylinder 37 is activated, it pushes the transmission clamping block 35 through the transmission rod 351. Block 35 slides up and down along guide post 36 to achieve the tensioning and loosening of expansion drum assembly 32. The upper end of transmission clamping block 3 is triangular, and the middle part has a conical surface structure 352 that cooperates with transmission area 323 of expansion drum assembly 32. When drive cylinder 37 pushes transmission clamping block 35 to move upward, conical surface structure 352 contacts the inner conical surface of transmission area 323. Through the principle of inclined plane force saving, the axial thrust is converted into radial tensioning force of expansion drum assembly 32, ensuring that elastic chuck 34 evenly clamps the workpiece. When moving in the opposite direction, the conical surface separates, and elastic chuck 34 resets and releases the workpiece.

[0020] To elaborate further, such as Figure 2 As shown, a buffer cavity 311 is formed between the tensioning zone 321 and the inner wall of the positioning cover 31. The cavity can be filled with damping material or have an air gap reserved to absorb the vibration and impact during drilling and milling and improve the stability of the workpiece.

[0021] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0022] Although this document uses a variety of terms, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this invention; interpreting them as any additional limitation would contradict the spirit of this invention.

Claims

1. A drilling and milling fixture for a machining center, comprising a mounting plate (1), a connecting plate (2), and a plurality of drilling and milling fixtures (3), characterized in that: The connecting plate (2) is fixedly installed on the upper end of the mounting plate (1). The drilling and milling fixture (3) includes a positioning cover (31), a drum assembly (32), a connecting flange (33), an elastic chuck (34), a transmission clamping block (35), a guide column (36), and a drive cylinder (37). The positioning cover (31) is annular, and the drum assembly (32) is fixedly installed inside the positioning cover (31). The drum assembly (32) is integrally formed and is a multi-layered cylindrical shape. The drum assembly (32) includes a tensioning area (321), a connecting area (322), and a transmission area (323). The elastic chuck (34) is installed inside the drum assembly (32), and the elastic chuck (34) is located inside the tensioning area (321) and the connecting area (322). The connecting flange (33) is installed inside the drum assembly (32). The connecting plate (2) is installed inside the tensioning area (321) and the lower end of the connecting flange (33) extends into the elastic clamp (34). The connecting plate (2) has several connecting holes (21) and limiting holes (22). The lower end of the expansion drum assembly (32) extends into the connecting hole (21) and is connected to the connecting plate (2). The guide post (36) passes through the limiting hole (22) and is connected to the lower end of the positioning cover (31). The lower end of the guide post (36) is fixedly connected to the transmission clamping block (35). The mounting plate (1) has several mounting holes (11). The driving cylinder (37) is fixedly connected to the mounting plate (1) at the lower end of the mounting hole (11). The lower end of the transmission clamping block (35) forms a transmission rod (351). The transmission rod (351) is connected to the driving cylinder (37).

2. The drilling and milling fixture for a machining center according to claim 1, characterized in that: The upper end of the transmission clamping block (35) is triangular and a conical structure (352) is provided in the middle of the upper end of the transmission clamping block (35).

3. A drilling and milling fixture for a machining center according to claim 1, characterized in that: A buffer cavity (311) is formed between the tensioning area (321) of the expansion drum assembly (32) and the interior of the positioning cover (31).

4. A drilling and milling fixture for a machining center according to claim 1, characterized in that: Several zero-point locators (4) are fixedly installed on the mounting platform (1).

5. A drilling and milling fixture for a machining center according to claim 1, characterized in that: The expansion drum assembly (32) has a threaded hole (324) in its transmission area (323).

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