Combined variable-diameter tool for heat treatment of shaft parts capable of reducing permeation resistance

Abstract

The utility model discloses a shaft part heat treatment combined reducing tool capable of reducing seepage resistance, which solves the problem that local soft spots exist after heat treatment due to the fact that the contact area between an existing tool and a shaft part is large, and comprises a bottom material disc, and mounting holes are formed in the bottom material disc; a supporting structure is connected into the mounting hole and connected with a discharging disc. A round hole is formed in the discharging disc, a combined sleeve is arranged in the round hole of the discharging disc, and the combined sleeve is used for connecting and supporting shaft parts. A plurality of cambered surface gradient guide structures are uniformly arranged on the inner wall of the combined sleeve in the circumferential direction, and each cambered surface gradient guide structure is gradually shrunk towards the axis of the combined sleeve from top to bottom; the shaft part is guided and centered through the cambered surface gradient guide structure, on one hand, the shaking amplitude of the shaft part in heat treatment can be reduced, so that radial deformation after heat is reduced, the contact area of the tool and the shaft part can be reduced to the maximum extent, and the problem that local soft spots exist after the shaft part is subjected to heat treatment is solved.

Description

Technical Field

[0001] The utility model belongs to a tool for hot processing of shaft parts, in particular to a combined diameter-changing tool for heat treatment of shaft parts which can reduce resistance to permeation. Background Art

[0002] Shaft components are widely used in engineering and machinery. To achieve high strength and extend service life, they must be heat treated. Heat treatment improves surface wear resistance, and carburizing and quenching can also enhance core toughness. However, due to the length of shaft components and the uncontrollable structural distortion and stress release associated with heat treatment, straightening is required after heat treatment to meet straightness requirements. This necessitates the selection of appropriate tooling to minimize heat treatment deformation.

[0003] In the existing design of combined variable-diameter tooling for heat treatment of shaft parts, due to the different zero radial dimensions of shafts, suitable tooling needs to be designed for each size of shaft parts, resulting in increased investment costs; in addition, shaft parts are generally hung, such as the intermediate shaft, and the hanging position is close to the center of the axis of the shaft parts; those that cannot be hung can only be squatted, such as the output shaft; most of the current tooling will contact the outer wall of the part, resulting in the carburizing atmosphere unable to penetrate into the contact area, which in turn leads to the problem of local soft spots (impermeability) after the shaft parts are heat treated.

[0004] Chinese patent CN220116640U discloses a combined tooling for carburizing heat treatment of shafts, including a base material tray, a spacer sleeve, a column, a material rack and a reducing chuck; positioning screw holes are arranged around the base material tray, and the positioning screw holes are arranged at least at the four corners of the base material tray; the material rack is connected by a number of equilateral hexagons II with equal wall thickness, and positioning through holes are arranged at the four corners; the bottom end of the column is provided with a thread matching the positioning screw hole and is assembled with the base material tray; the upper end of the column is inserted into the spacer sleeve and passes through the positioning through hole of the material rack; the reducing chuck is provided with three 120-degree evenly distributed limit ears, a number of support protrusions and a parts installation positioning inner hole. This patent adopts a split combination design of a material rack and a reducing chuck, which can only meet the versatility of shaft parts that can be hung, and is not suitable for squatting. Moreover, when in use, the contact area of the shaft parts and the tooling is too large. After the shot blasting process, white soft spots will appear on the contact parts because the carburizing atmosphere cannot penetrate into the contact parts; and because the limit hanging ears are fixed on the periphery of the material rack, they occupy the space of the adjacent material rack holes, resulting in the parts having to be equipped in a misplaced manner. Utility Model Content

[0005] The purpose of the utility model is to solve the problem that the existing tooling has a large contact area with shaft parts, resulting in local soft spots (impermeability) after heat treatment, and to provide a combined diameter-changing tooling for heat treatment of shaft parts that reduces impermeability.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A combined diameter-reducing tool for heat treatment of shaft parts for reducing permeation resistance includes a base tray with 4n mounting holes, where n is greater than or equal to 1; each mounting hole of the base tray is connected to the bottom end of a support structure, and the top of every four support structures is connected to a discharge tray; the discharge tray has m circular holes, where m is greater than or equal to 4, and a combined sleeve is disposed in each circular hole of the discharge tray. The combined sleeve is used to connect and support shaft parts. The special feature of the tool is that:

[0008] The inner wall of the combination sleeve is evenly provided with multiple arc-surface gradual guide structures along the circumferential direction. The arc-surface gradual guide structure extends from top to bottom in the axial direction, and the cross-section in the radial direction is an arc-shaped structure that bulges toward the axial direction of the combination sleeve. The height of each arc-surface gradual guide structure gradually increases from top to bottom. The arc-surface gradual guide structure guides and centers the shaft parts, minimizes the contact area between the tooling and the shaft parts, and solves the problem of local soft spots (impermeability) of the shaft parts after heat treatment.

[0009] There are four arc-surface gradual guide structures. Too many of them will lead to poor fluidity of the carburizing atmosphere, while too few of them will make shaft parts easily deviate from the center of the combined sleeve.

[0010] A plurality of support blocks are arranged at equal intervals on one end of the combined sleeve away from the bottom material tray, and each support block is arranged near the inner wall of the combined sleeve to play a role in stably supporting shaft parts.

[0011] The upper end of each support block is rounded all around to increase the fluidity of the carburizing atmosphere. The support block and the rounded corners at both ends can reduce the contact area between the shaft parts and the tooling, thereby promoting uniform heat treatment of the shaft parts.

[0012] There are four support blocks, and the setting position of each support block corresponds to the arc surface gradual guide structure one by one, thereby improving the stability of supporting shaft parts.

[0013] The longitudinal cross-section of the combined sleeve is mushroom-shaped, wherein the outer diameter dimension of the small diameter end is b, the outer diameter dimension of the large diameter end is e, and the aperture of the circular hole is d. The dimensions of the combined sleeve and the circular hole satisfy: b≤d<e, which makes it easy to insert the combined sleeve into the discharge tray. The structure is simple, stable and durable, low cost, and suitable for batch use.

[0014] Each of the supporting structures includes a column, each column is sleeved with multiple supporting sleeves, the bottom end of the column is connected to each mounting hole of the bottom material tray, and the upper part of the column located on the multiple supporting sleeves is connected to the discharge tray.

[0015] Four column holes are provided on the discharge tray for connecting columns.

[0016] The value of n is 2.

[0017] There are multiple types of combined sleeves, and the inner diameter of each combined sleeve is adapted to the outer diameter of the shaft part that needs to be heat treated.

[0018] Beneficial effects of the utility model:

[0019] 1. In the utility model, a combined diameter reducing tool for heat treatment of shaft parts that reduces permeation resistance is provided. The combined sleeve is placed in the circular hole of the discharge tray, which is convenient for disassembly. The inner diameter of the combined sleeve is adapted to the outer diameter of the shaft part to be heat treated, which can meet the versatility of shaft parts of various specifications and reduce investment costs.

[0020] 2. In a combined diameter-changing fixture for heat treatment of shaft parts that reduces resistance to permeation, the utility model features multiple cambered gradually changing guide structures evenly arranged along the circumference of the inner wall of a combined sleeve. Each cambered gradually changing guide structure gradually contracts from top to bottom toward the axis of the combined sleeve, guiding and centering the shaft part. This reduces the amplitude of shaking during heat treatment of the shaft part, thereby reducing radial deformation after heat treatment, facilitating part loading and unloading by operators, and minimizing the contact area between the fixture and the shaft part, thereby resolving the problem of localized soft spots (resistance to permeation) in shaft parts after heat treatment.

[0021] 3. In the utility model, a combined reducing tool for heat treatment of shaft parts that reduces permeation resistance, multiple support blocks are evenly spaced and connected to the end of the combined sleeve away from the base plate. Each support block extends in the axial direction of the combined sleeve to provide stable support for the shaft part. The two corners on the upper end of each support block are rounded to increase the fluidity of the carburizing atmosphere. The design of the support blocks and the rounded corners on both ends can reduce the contact area between the shaft part and the tool, promoting uniform heat treatment of the shaft part.

[0022] 4. In the utility model, a combined reducing tool for heat treatment of shaft parts to reduce resistance to permeation, the longitudinal section of the combined sleeve is mushroom-shaped, and the end with a small outer diameter can be inserted into the discharge tray. It has the advantages of simple structure, stability and durability, low cost, and suitability for batch use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of an embodiment of a combined diameter-reducing tooling for heat treatment of shaft parts for reducing permeation resistance according to the utility model;

[0024] Figure 2 This is a structural diagram of a discharge tray in an embodiment of a combined diameter-changing tooling for heat treatment of shaft parts for reducing permeation resistance of the utility model;

[0025] Figure 3This is a schematic diagram of the three-dimensional structure of a combined sleeve in an embodiment of a combined diameter-reducing tooling for heat treatment of shaft parts for reducing permeation resistance of the utility model;

[0026] Figure 4 This is a side view of a combined sleeve in an embodiment of a combined diameter-reducing tooling for heat treatment of shaft parts for reducing permeation resistance of the utility model;

[0027] Figure 5 This is an assembly diagram of shaft parts and combined sleeves in an embodiment of the present utility model.

[0028] In the figure, 1. bottom material tray, 2. discharge tray, 3. combination sleeve, 4. support block, 5. arc surface gradient guide structure, 6. shaft parts, 7. column, 8. support sleeve, 9. column hole. DETAILED DESCRIPTION

[0029] The following will be combined with the accompanying drawings and embodiments to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] Example

[0031] In this embodiment, a heat treatment combined variable diameter tooling for shaft parts to reduce permeation resistance is provided. Figure 1 As shown, it includes a bottom material tray 1 with eight mounting holes; each mounting hole of the bottom material tray 1 is connected to the bottom end of a column 7, and each column 7 is sleeved with three supporting sleeves 8, and the four columns 7 are located in the column holes 9 connected to the upper part of the three supporting sleeves 8 connected to the discharge tray 2, which play a supporting and connecting role for the four corners of the discharge tray 2; this embodiment adopts a structure of one bottom material tray 1 and two discharge trays 2, wherein each discharge tray 2 is supported and connected by four columns 7 and twelve supporting sleeves 8, thereby increasing the stability of the overall structure.

[0032] like Figure 1 and Figure 2 As shown, the discharge tray 2 has forty-six circular holes, each of which is provided with a combination sleeve 3. The combination sleeve 3 is arranged in the circular holes of the discharge tray 2 for easy removal. The inner diameter of the combination sleeve 3 is adapted to the outer diameter of the shaft part 6 to be heat treated, thereby meeting the versatility of shaft parts of various specifications and reducing investment costs.

[0033] like Figure 3As shown, the inner wall of the combined sleeve 3 is uniformly circumferentially provided with multiple cambered guide structures 5. These cambered guide structures 5 extend axially from top to bottom, and their radial cross-sections form arcs that bulge toward the axis of the combined sleeve 3. The height of each cambered guide structure 5 gradually increases from top to bottom. These cambered guide structures 5 guide and center the shaft component 6, facilitating component loading and unloading by operators and minimizing the contact area between the tooling and the shaft component 6. This addresses the problem of localized soft spots (permeation resistance) that can occur in shaft components after heat treatment.

[0034] like Figure 4 As shown, four support blocks 4 with rounded corners on the upper ends are evenly spaced and connected to the end of the combined sleeve 3 away from the bottom material plate 1. This can increase the fluidity of the carburizing atmosphere and reduce the contact area between the shaft parts and the tooling, thereby promoting uniform heat treatment of the shaft parts.

[0035] The setting position of each support block 4 corresponds one-to-one to the arc-surface gradual guide structure 5. Since the support block 4 is higher than the combined sleeve 3, the arc-surface gradual guide structure 5 corresponds to the support block 4, which will increase the lead of the arc-surface gradual guide structure 5 and make the transition of the shaft parts 6 installed in the combined sleeve 3 smoother.

[0036] like Figure 5 As shown, the longitudinal cross-section of the combined sleeve 3 is mushroom-shaped, with the outer diameter of the smaller end being b, the larger end being e, and the diameter of the circular hole being d. The dimensions of the combined sleeve and the circular hole satisfy the following relationship: b ≤ d < e. The smaller end can be inserted into the discharge tray 2, resulting in a simple structure, stability, durability, low cost, and suitability for mass production.

[0037] According to the outer diameter of the shaft part to be heat treated, a combination sleeve 3 with an adapted inner diameter is selected, and the combination sleeve 3 is placed in the circular hole of the discharge tray 2, and the shaft part 6 is connected to a schematic diagram of a combined diameter reducing tooling for heat treatment of shaft parts with reduced resistance to permeation. Figure 5 As shown, the shaft part 6 is placed from the upper end of the combined sleeve 3, supported by four support blocks 4, and centrally supported by the arc surface gradient guide structure 5. After placement, heat treatment can be performed.

[0038] The above description is merely a specific embodiment of the present invention, and a comparison of the effects of the specific embodiment with the corresponding comparative examples. However, the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention shall be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope of protection of the claims.

Claims

1. A combined diameter-changing tool for heat treatment of shaft parts for reducing permeation resistance, comprising a bottom material tray (1), wherein 4n mounting holes are provided on the bottom material tray (1), wherein n≥1; each mounting hole of the bottom material tray (1) is connected to the bottom end of a supporting structure, and the top ends of every four supporting structures are connected to a discharge tray (2); each discharge tray (2) is provided with m circular holes, wherein m≥4, and a combined sleeve (3) is provided in each circular hole of the discharge tray (2); the characteristics are: The inner wall of the combined sleeve (3) is evenly provided with a plurality of arc-surface gradual guide structures (5) along the circumferential direction. The arc-surface gradual guide structures (5) are arc-shaped structures extending from top to bottom in the axial direction and having a radial cross-section that is convex toward the axis of the combined sleeve (3). The convex height of each arc-surface gradual guide structure (5) gradually increases from top to bottom.

2. The heat treatment combined diameter reducing fixture for shaft parts with reduced permeation resistance according to claim 1, characterized in that: There are four arc-surface gradual guide structures (5).

3. The heat treatment combined diameter reducing fixture for shaft parts with reduced permeation resistance according to claim 2, characterized in that: A plurality of support blocks (4) are arranged at equal intervals on one end of the combined sleeve (3) away from the bottom material plate (1), and each support block (4) is arranged near the inner wall of the combined sleeve (3).

4. The heat treatment combined diameter reducing fixture for shaft parts with reduced permeation resistance according to claim 3, characterized in that: The upper end of each support block (4) is rounded all around.

5. A combined diameter reducing tool for heat treatment of shaft parts to reduce permeation resistance according to claim 3 or 4, characterized in that: There are four support blocks (4), and the setting position of each support block (4) corresponds one-to-one to the arc-surface gradual guide structure (5).

6. The heat treatment combined diameter reducing tool for shaft parts with reduced permeation resistance according to claim 1, characterized in that: The longitudinal section of the combined sleeve (3) is mushroom-shaped, wherein the outer diameter dimension of the small diameter end is b, the outer diameter dimension of the large diameter end is e, and the aperture of the circular hole is d. Then, the dimensions of the combined sleeve (3) and the circular hole satisfy: b≤d<e.

7. The heat treatment combined diameter reducing tool for shaft parts with reduced permeation resistance according to claim 1, characterized in that: Each of the supporting structures comprises a column (7), a plurality of supporting sleeves (8) are sleeved on each column (7), the bottom end of the column (7) is connected to each mounting hole of the bottom material tray (1), and the upper part of the column (7) located above the plurality of supporting sleeves (8) is connected to the discharge tray (2).

8. The heat treatment combined diameter reducing fixture for shaft parts with reduced permeation resistance according to claim 7, characterized in that: Four column holes (9) are provided on the discharge tray (2) for connecting the columns (7).

9. A combined diameter-reducing tool for heat treatment of shaft parts to reduce permeation resistance according to claim 1 or 7, characterized in that: The value of n is 2.

10. The heat treatment combined diameter reducing tool for shaft parts with reduced permeation resistance according to claim 1, characterized in that: There are multiple types of combined sleeves (3), and the inner diameter of each type of combined sleeve (3) is adapted to the outer diameter of the shaft part that needs to be heat treated.

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