Adjustable diameter stretch rod

Abstract

The utility model discloses a diameter adjustable pull long mandrel, which comprises a mandrel, a working section of the mandrel has an outer conical surface; a sleeve is sleeved on the working section, and the inner wall of the sleeve is provided with an inner conical surface matched with the working section; the length of the sleeve is the same as the length of the working section of the mandrel; a key connection structure is arranged between the end of the mandrel and the sleeve, and is used for limiting the relative circumferential movement of the sleeve and the mandrel; and a fastener is used for connecting and fixing the key connection structure on the mandrel. The utility model realizes that one mandrel is adapted to multiple specifications of sleeves, thereby reducing the consumption of the pull long mandrel, lowering the cost, improving the use flexibility, and being simple in structure and convenient to manufacture, and being suitable for the cold drawing forming process of various metal pipes and bars.

Description

Technical Field

[0001] This utility model belongs to the field of cold drawing technology, and specifically relates to a drawing mandrel with adjustable diameter. Background Technology

[0002] In the cold drawing of metal tubes or bars, the drawing mandrel is a key tool for controlling the inner diameter of the product. Traditional drawing mandrels are mostly of fixed size, meaning that one type of mandrel is only suitable for processing products with one inner diameter. In actual production, to accommodate products of different specifications, multiple mandrels of different sizes are required, resulting in a large number of mandrels, complex storage and management, and high procurement and maintenance costs.

[0003] Existing technologies typically use multiple fixed-size mandrels for fitting, which can achieve processing, but has the following drawbacks: (1) The number of core rods is large, which takes up a lot of space and is inconvenient to manage; (2) High manufacturing costs and large amounts of repetitive investment; (3) When switching specifications, the entire mandrel needs to be replaced, which is cumbersome and affects production efficiency. Utility Model Content

[0004] To address the aforementioned issues, this invention provides an adjustable diameter drawing mandrel. Through the combination structure of the mandrel and sleeve, a single mandrel can be adapted to various sleeve specifications, thereby reducing material consumption, lowering costs, and improving flexibility of use. The structure is simple, easy to manufacture, and suitable for cold drawing forming processes of various metal pipes and rods.

[0005] The main technical solution adopted in this utility model is as follows: An adjustable diameter drawing mandrel, comprising: The mandrel has an outer conical surface in its working section; A sleeve is fitted onto the working section, and the inner wall of the sleeve is provided with an inner conical surface that mates with the working section. The length of the sleeve is the same as the length of the working section of the mandrel. A keyed connection structure is provided between the ends of the mandrel and the sleeve to restrict relative circumferential movement between the sleeve and the mandrel; Fasteners are used to connect and fix the key connection structure to the mandrel.

[0006] Preferably, the key connection structure includes keyway I, keyway II, and connecting key. Keyway I is located at the working end of the mandrel, and keyway II is located at the end of the sleeve. The positions of keyway I and keyway II correspond one-to-one and work together to form a complete keyway space. The connecting key is installed in the keyway space to achieve circumferential fixation between the mandrel and the sleeve.

[0007] Preferably, the connecting key is a cross key, and the keyway I and keyway II cooperate to form a cross keyway that cooperates with the cross key.

[0008] Preferably, the working section end face of the mandrel is provided with a threaded hole at its center, the connecting key is provided with a through hole at its center, and the fastener passes through the connecting key and connects to the threaded hole of the mandrel.

[0009] Preferably, the end face of the sleeve is provided with a lifting hole.

[0010] Preferably, the outer conical surface of the mandrel working section and the outer conical surface of the inner wall of the sleeve have the same taper.

[0011] Preferably, the outer wall of the sleeve has a conical surface.

[0012] Beneficial effects: This utility model provides a drawing mandrel with an adjustable diameter, which has the following advantages: (1) In this utility model, a combination structure of mandrel and sleeve is adopted. One mandrel can be adapted to multiple specifications of sleeve. By changing the sleeve, the processing requirements of products with different inner diameters can be met, which significantly reduces the number of mandrels purchased, reduces equipment investment, and improves equipment utilization and production flexibility.

[0013] (2) In this utility model, the mandrel and the sleeve are connected by a tapered surface and a key to ensure smooth torque transmission and effectively prevent slippage during operation; and the axial clamping force is applied to the sleeve by the cross key to fix its axial relative position with the mandrel.

[0014] (3) In this utility model, when changing product specifications, only the sleeve needs to be replaced, without disassembling the entire mandrel system. The operation is simple and quick, greatly improving production efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a right view of the overall structure of this utility model; Figure 3 This is a schematic diagram of the mandrel structure of this utility model; Figure 4 This is a right view of the mandrel structure of this utility model; Figure 5 This is a schematic diagram of the sleeve structure of this utility model; Figure 6 This is a right view of the sleeve structure of this utility model; Figure 7 This is a schematic diagram of the cross-shaped key structure of this utility model; Figure 8 This is a vertical cross-sectional view of the cross-key structure of this utility model; In the figure: mandrel 1, clamping section 1-1, working section 1-2, keyway I 1-3, threaded hole 1-4, sleeve 2, keyway II 2-1, lifting hole 2-2, connecting key 3, through hole 3-1, fastener 4. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application. Example 1:

[0017] like Figure 1 and 2 As shown, an adjustable diameter drawing mandrel includes a mandrel 1, a sleeve 2, a connecting key structure, and a fastener 4.

[0018] like Figure 3 and 4 As shown, the mandrel 1 includes a clamping section 1-1 and a working section 1-2. The working section 1-2 has an outer conical surface. Figure 4 As shown, the small end of the working section 1-2 has a threaded hole at its center, and a cross-shaped keyway I1-3 is provided on this end face. In this utility model, the clamping section 1-1 and the working section 1-2 are preferably integrally formed.

[0019] like Figure 5 and 6 As shown, sleeve 2 is fitted onto working section 1-2, and the inner wall of sleeve 2 has an inner conical surface that mates with working section 1-2. The two have the same taper; in this embodiment, the taper is preferably 1:160. The length of sleeve 2 is the same as the length of working section 1-2 of mandrel 1. One end face of sleeve 2 (corresponding to the small end of the working section of mandrel) is provided with keyway II 2-1. In this embodiment, as... Figure 6 As shown, keyway II2-1 includes four cross-shaped openings, with the same axial depth as keyway I1-3. The sleeve 2 also has a lifting hole 2-2 at the same end as keyway II2-1. The outer wall of sleeve 2 is designed as a tapered surface with a taper of 1:160.

[0020] like Figure 1 and 2 As shown, the key connection structure is installed between the ends of the mandrel 1 and the sleeve 2 to restrict the relative circumferential movement between the sleeve 2 and the mandrel 1.

[0021] In this embodiment, as Figure 4 and 6As shown, the key connection structure includes keyway I1-3, keyway II2-1, and connecting key 3. During assembly, the four openings of keyway II2-1 are respectively connected to the cross-shaped keyway I1-3, forming a complete cross-shaped keyway space. Figure 7 As shown, the connecting key 3 is a cross key, which is adapted to the cross keyway space and installed in the keyway space to achieve circumferential fixation of the spindle 1 and the sleeve 2.

[0022] Figure 1 and 8 As shown, fastener 4 connects and fixes the key connection structure to the mandrel 1. A threaded hole 1-4 is provided at the center of the working section end face of the mandrel 1, and a through hole 3-1 is provided at the center of the connecting key 3. The fastener passes through the connecting key 3 and connects to the threaded hole of the mandrel 1. In this embodiment, the fastener 4 is a fastening screw, and the through hole 3-1 can be a countersunk hole.

[0023] The working principle of this utility model is as follows: Based on the inner diameter of the product to be drawn, a sleeve 2 with a corresponding outer diameter specification can be selected. The sleeve 2 is hoisted through the hoisting hole 2-2 and fitted onto the working section 1-2 of the mandrel 1, aligning the keyway II 2-1 on the sleeve 2 with the keyway I 1-3 on the mandrel 1. The connecting key 3 is inserted into the cross-shaped keyway space formed after alignment, and then a fastening screw 4 is passed through the connecting key 3 and screwed into the threaded hole of the mandrel 1 for tightening. During tightening, the fastener 4 applies axial pressure to the sleeve 2 through the connecting key 3. Combined with the tapered surface fit, this firmly fixes the relative axial position of the sleeve 2 and the mandrel 1, ensuring stable torque transmission. After the drawing process is completed, the tapered outer wall of the sleeve 2 facilitates demolding from the product.

[0024] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

Claims

1. A drawing mandrel with adjustable diameter, characterized in that, include: The mandrel (1) has a working section (1-2) with an outer conical surface; A sleeve (2) is fitted onto the working section (1-2), and the inner wall of the sleeve is provided with an inner conical surface that matches the working section (1-2). The length of the sleeve (2) is the same as the length of the working section (1-2) of the mandrel (1). A key connection structure is provided between the ends of the mandrel (1) and the sleeve (2) to restrict the relative circumferential movement between the sleeve and the mandrel (1); Fasteners are used to connect and fix the key connection structure to the mandrel (1).

2. The adjustable diameter drawing mandrel according to claim 1, characterized in that, The key connection structure includes keyway I (1-3), keyway II (2-1) and connecting key (3). Keyway I (1-3) is located at the working end of the mandrel, and keyway II (2-1) is located at the end of the sleeve. The positions of keyway I (1-3) and keyway II (2-1) correspond one-to-one and work together to form a complete keyway space. The connecting key (3) is installed in the keyway space to achieve circumferential fixation between the mandrel and the sleeve.

3. The adjustable diameter drawing mandrel according to claim 2, characterized in that, The connecting key (3) is a cross key, and the keyway I (1-3) and keyway II (2-1) cooperate to form a cross keyway that cooperates with the cross key.

4. The adjustable diameter drawing mandrel according to claim 2, characterized in that, The working section end face of the mandrel (1) is provided with a threaded hole at the center, and the connecting key (3) is provided with a through hole at the center position. The fastener passes through the connecting key (3) and is connected to the threaded hole of the mandrel (1).

5. The adjustable diameter drawing mandrel according to claim 1, characterized in that, The end face of the sleeve (2) is provided with a lifting hole (2-2).

6. The adjustable diameter drawing mandrel according to claim 1, characterized in that, The outer conical surface of the working section (1-2) of the mandrel (1) and the outer conical surface of the inner wall of the sleeve (2) have the same taper.

7. The adjustable diameter drawing mandrel according to claim 1, characterized in that, The outer wall of the sleeve (2) is a conical surface.

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